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https://ajayshahblog.blogspot.com/2016/05/understanding-judicial-delays-in-india.html
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Wednesday, May 18, 2016
Understanding judicial delays in India: Evidence from Debt Recovery Tribunals
by Prasanth Regy, Shubho Roy and Renuka Sane
The Insolvency and Bankruptcy Code passed by the Lok Sabha last week envisages Debt Recovery Tribunals (DRTs) as the adjudicating authority for individuals and partnership firms. When originally set up, DRTs were expected to resolve cases within a limit of 180 days. But experience tells us that judicial delay is as much of a problem in the DRTs as with other courts.
There is a great uproar about judicial delays in India today. We are now a country where it is widely felt that we know how to run elections but we don't know how to run courts. A commonly touted solution is to hire more judges. However, if the institutional arrangements in which judges operate is faulty, adding more judges is not likely to help.
In fact, little is known about why delays occur. The present approach of collecting information about judicial delays concentrates on a few macro-level statistics of pendency and disposal rates. There is very limited information or research that uses micro data about the time taken for judicial proceedings, and the reasons for the delay. In this article, we bring a novel research strategy to bear on understanding the issue of judicial delays. While this strategy is general, we apply it to Debt Recovery Tribunals (DRTs), and present our findings.
1 Debt recovery tribunals
Debt Recovery Tribunals (DRTs) are statutory bodies established under the Recovery of Debts Due to Banks and Financial Institutions Act, 1993. They were created because the existing mechanisms of debt recovery were ineffective. DRTs were expected to enable the "expeditious adjudication and recovery of debts" within one hundred and eighty days of filing the case. Subsequently, DRTs have also been tasked with enforcing some provisions of the Securitisation and Reconstruction of Financial Assets and Enforcement of Security Interest Act (SARFAESI), and of the Insolvency and Bankruptcy Code, 2015.
DRTs have not been successful in realising the objective of efficient disposal of debt-related disputes. We knew, at the time of the creation of DRTs, that the previous debt-resolution mechanisms were slow and ineffective. The DRTs were meant to be an antidote to this problem. But now, more than 20 years after DRTs were set up, we know (Committee on Financial Reforms, 2009) that the DRTs have not been any faster than other courts in resolving issues.
2 Questions
If DRTs suffer from long delays, they will not be able to fulfil the new Insolvency and Bankruptcy Code-related responsibilities placed on them. So how can DRTs work better and faster? An answer to this question depends upon the answers to many other questions: Who causes delays at DRTs? What is the immediate cause of these delays, and what is their root cause? What is the role of the tribunal in enabling delays? And importantly, what are the incentives of the different stakeholders that lead to delays? Answering these questions is key to designing and implementing reforms to make our courts work better.
3 A dataset about the working of debt recovery tribunals
We hand-constructed micro data for a sample of cases disposed by the Debt Recovery Tribunal (DRT) in Delhi. We obtained complete information for 22 cases disposed between February and April 2014. The earliest of these cases had been instituted in 2006, and the last in 2013. We captured information about who filed the case, against whom, and the key issue at stake. At the end of each hearing, an order is passed. We analysed each hearing and each order. This yielded observations of 474 orders over these 22 cases, an average of 21.5 orders per case. We captured data about the date of the order, the content of the order and the date of the next order. If there was an adjournment, we noted who asked for it and why.
The data files have been released here.
4 How large are the delays
When a hearing resulted in an avoidable and unpenalised adjournment, we classified it as a failure. Most often, these adjournments were requested by one of the parties, but sometimes they are caused by the tribunal itself. On average, each failure adds about a month of delay to the case.
The cases we examined went on for about 2.7 years on average. This conceals a lot of variance — the duration varied from as few as 5 months to as many as seven and a half years. See Figure 1 below:
Figure 1: Histogram of the case duration
How much of this was necessary? In other words, if the system had functioned well, how much delay could have been avoided? It turns out that of these 474 hearings, 279 hearings (about 60%) were failures. These failures induced half the delay.
Can we envision a world where trial failures are eliminated? At first blush, it seems that we could reduce the duration of the average case by roughly half if we are able to eliminate trial failures. The full gain is, however, larger than this. If there were fewer trial failures, cases would finish sooner, freeing up slots on the judicial dockets. This would let other cases have more frequent hearings. So the delay would drop by more than half if these failures were avoided.
5 Who causes delays: borrower or lender?
At DRTs, there are broadly two kinds of cases: those filed by the lender, and those filed by the borrower. The cases filed by borrowers typically ask the tribunal to stop action taken by the lenders under SARFAESI. In these cases, one would expect that the borrowers would have an incentive to delay: they already have use of the money, and they would like to repay as late as possible. This is indeed what's seen in the data. For the cases filed by borrowers, adjournments due to the borrower account for 46% of the total time lost, while about 21% is lost due to the lender, and about 17% due to the tribunal (see Figure 2).
Figure 2: Who delayed?
In the cases filed by the lender, one would expect that the lender-petitioner would want a quick disposal of the case. After all, it has lent the money, and would presumably like it back as soon as possible. Besides, these lenders are sophisticated institutions that maintain proper documentation and have expensive lawyers in their service.
Remarkably enough, in these cases, the petitioner is the major cause of delays. The lender-petitioner accounts for 37% of the delay, compared to 20% caused by the defendant and 26% by the tribunal. Many of these delays are because the lender asks for adjournments while it locates and files documents. This clearly violates our expectation that the lender would want his money back quickly. Given that they have good documentation and good quality legal counsel, it is not clear why they would take so long to perform tasks that lie well within their control.
6 Looking deeper into the delays
This raises several questions. Why do lenders file cases in courts, and then ask for so many adjournments? Is it possible that their objective in filing the case is not to obtain a judicial mandate in their favour, but to exert pressure on the borrower to come to a negotiated settlement? The large number of cases that seem to be settled outside the court-room (about half of the cases we studied) would seem to indicate so.
It is likely that the cost of prolonging a legal fight is lower for a financial institution than for most borrowers. Financial institutions have legal departments and lawyers on retainers, while for most small borrowers, the legal system is a source of anxiety and expense. Perhaps banks delay, in the expectation that the borrower would wilt under the pressure and would be willing to come to a negotiated agreement.
But if we look at Figure 2, about 70% of the delays are due to the lawyers. The large number of times the lawyers (on both sides) ask for more time to file documents, as well as the many instances where one or the other (often both) lawyers are absent, or both lawyers request adjournments, suggests another possibility: that the lawyers are in no hurry to finish the case. If the incentives of the lawyers are perverse — for instance, if they get paid not on the basis of prompt resolution of the case in favour of their client, but on the basis of the number of hearings — then it is reasonable to expect that they would prefer to have more hearings.
An important weak link is the behaviour of the court. Those asking for repeated adjournments are imposing a cost on the judiciary. Judicial time and capacity are scarce public resources, and repeated delays are a waste of these precious resources. In spite of this, we have seen very little evidence of the court imposing penalties on the parties for causing delays. There is emotion about hiring more judges, but not about cracking down on delaying tactics.
Another facet of the data is how often the tribunal itself causes delays. Figure 2 shows that more than a quarter of the time lost is attributable to the court. The reasons are many: the registrar might be on leave, the judge may be attending a conference, or the bar association might have requested a holiday. Most other institutions find ways to ensure that work is not held up due to such reasons. As an example, a railway station or a stock exchange or a bank branch works all the time.
7 Conclusions
To summarise, our study has shown that more than half the time of a case is lost in avoidable and unpenalised adjournments. The parties to the case, the lawyers, and the tribunals, all participate in this delay. The study indicates that lenders may use court delays as a strategy to pressure the borrower to come to a negotiated agreement. Lawyers may have perverse incentives to draw out cases, and tribunals often contribute to delay themselves due to administrative reasons.
These results suggest two clear directions for reform:
1. Laws must provide incentives for litigants, lawyers, and judges to reduce litigation time. For an example, see here on how smart drafting of rules can create incentives to quickly resolve disputes.
2. Poor administrative processes also contribute to delays. Judicial time gets wasted because the administrative functions of a case (like serving notices) have not been completed. The solution to this is better administration, through investment in the court infrastructure, as well as through the separation of administrative and judicial functions of the tribunal.
Such reform should be grounded in a sophisticated understanding of the value (to a protagonist) and the cost (to society) of judicial delays, and it should be guided by the principles of law, economics, and public administration. The work we have presented above is a step in this direction. Future work will aim to derive rigorous inferences about the causes of delay, the incentives of the various stakeholders, and how these incentives could be modified.
References
Committee on Financial Sector Reforms. A Hundred Small Steps: Report of the Committee on Financial Sector Reforms. Planning Commission, Government of India, 2009.
Martin A. Levin. Delay in Five Criminal Courts. The Journal of Legal Studies, Vol. 4, No. 1, pp. 83-131, January 1975.
Richard A. Posner. An Economic Approach to Legal Procedure and Judicial Administration. Journal of Legal Studies, 399--458, 1973.
Shubho Roy. Reducing delays in litigation by reshaping the incentives of litigants. Ajay Shah's Blog, January 8, 2016.
Pratik Datta and Ajay Shah. How to make courts work? Ajay Shah's Blog, February 22, 2015.
Pratik Datta. Transforming the operational efficiency of tribunals and courts. Ajay Shah's Blog, February 8, 2016.
Prasanth Regy and Shubho Roy are researchers at the National Institute of Public Finance and Policy. Renuka Sane is an academic at the Indian Statistical Institute. We thank Anirudh Burman, Pratik Datta, Kushagra Priyadarshi and Sanhita Sapatnekar for their participation and contributions in the early stages of this research project.
Please note: LaTeX mathematics works. This means that if you want to say $10 you have to say \$10.
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https://dlmf.nist.gov/9.2
|
# §9.2 Differential Equation
## §9.2(i) Airy’s Equation
9.2.1 $\frac{{\mathrm{d}}^{2}w}{{\mathrm{d}z}^{2}}=zw.$ ⓘ Defines: $w$: ODE solution (locally) Symbols: $\frac{\mathrm{d}\NVar{f}}{\mathrm{d}\NVar{x}}$: derivative of $f$ with respect to $x$ and $z$: complex variable Source: Olver (1997b, (1.01), p. 392) A&S Ref: 10.4.1 (in slightly different form) Referenced by: §36.8, 9.10.10, 9.10.20, 9.10.21, 9.10.8, 9.10.9, §9.10(iii), 9.11.2, §9.11(i), §9.11(iv), §9.12(i), §9.17(ii), §9.17(ii), 9.2.16, §9.2(iii), §9.2(vi), 9.8.14, 9.8.16, 9.8.18, 9.8.19 Permalink: http://dlmf.nist.gov/9.2.E1 Encodings: TeX, pMML, png See also: Annotations for 9.2(i), 9.2 and 9
All solutions are entire functions of $z$.
Standard solutions are:
9.2.2 $w=\mathrm{Ai}\left(z\right),\;\mathrm{Bi}\left(z\right),\;\mathrm{Ai}\left(ze^% {\mp 2\pi\mathrm{i}/3}\right).$ ⓘ Symbols: $\mathrm{Ai}\left(\NVar{z}\right)$: Airy function, $\mathrm{Bi}\left(\NVar{z}\right)$: Airy function, $\pi$: the ratio of the circumference of a circle to its diameter, $\mathrm{e}$: base of natural logarithm, $z$: complex variable and $w$: ODE solution Source: Olver (1997b, pp. 392–393, 413–414) Permalink: http://dlmf.nist.gov/9.2.E2 Encodings: TeX, pMML, png See also: Annotations for 9.2(i), 9.2 and 9
## §9.2(ii) Initial Values
9.2.3 $\displaystyle\mathrm{Ai}\left(0\right)$ $\displaystyle=\frac{1}{3^{2/3}\Gamma\left(\tfrac{2}{3}\right)}=0.35502\;80538\ldots,$ ⓘ Symbols: $\mathrm{Ai}\left(\NVar{z}\right)$: Airy function and $\Gamma\left(\NVar{z}\right)$: gamma function Source: Olver (1997b, (1.03), p. 392) A&S Ref: 10.4.4 (with more digits) Permalink: http://dlmf.nist.gov/9.2.E3 Encodings: TeX, pMML, png See also: Annotations for 9.2(ii), 9.2 and 9 9.2.4 $\displaystyle\mathrm{Ai}'\left(0\right)$ $\displaystyle=-\frac{1}{3^{1/3}\Gamma\left(\tfrac{1}{3}\right)}=-0.25881\;9403% 7\ldots,$ ⓘ Symbols: $\mathrm{Ai}\left(\NVar{z}\right)$: Airy function and $\Gamma\left(\NVar{z}\right)$: gamma function Source: Olver (1997b, (1.03), p. 392) A&S Ref: 10.4.5 (with more digits) Permalink: http://dlmf.nist.gov/9.2.E4 Encodings: TeX, pMML, png See also: Annotations for 9.2(ii), 9.2 and 9 9.2.5 $\displaystyle\mathrm{Bi}\left(0\right)$ $\displaystyle=\frac{1}{3^{1/6}\Gamma\left(\tfrac{2}{3}\right)}=0.61492\;66274\ldots,$ ⓘ Symbols: $\mathrm{Bi}\left(\NVar{z}\right)$: Airy function and $\Gamma\left(\NVar{z}\right)$: gamma function Source: Olver (1997b, (1.11), p. 393) A&S Ref: 10.4.4 (in different form) Referenced by: 9.12.15 Permalink: http://dlmf.nist.gov/9.2.E5 Encodings: TeX, pMML, png See also: Annotations for 9.2(ii), 9.2 and 9 9.2.6 $\displaystyle\mathrm{Bi}'\left(0\right)$ $\displaystyle=\frac{3^{1/6}}{\Gamma\left(\tfrac{1}{3}\right)}=0.44828\;83573\ldots.$ ⓘ Symbols: $\mathrm{Bi}\left(\NVar{z}\right)$: Airy function and $\Gamma\left(\NVar{z}\right)$: gamma function Source: Olver (1997b, (1.11), p. 393) A&S Ref: 10.4.5 (in different form) Referenced by: 9.12.15 Permalink: http://dlmf.nist.gov/9.2.E6 Encodings: TeX, pMML, png See also: Annotations for 9.2(ii), 9.2 and 9
## §9.2(iii) Numerically Satisfactory Pairs of Solutions
Table 9.2.1 lists numerically satisfactory pairs of solutions of (9.2.1) for the stated intervals or regions; compare §2.7(iv).
## §9.2(iv) Wronskians
9.2.7 $\mathscr{W}\left\{\mathrm{Ai}\left(z\right),\mathrm{Bi}\left(z\right)\right\}=% \frac{1}{\pi},$ ⓘ Symbols: $\mathrm{Ai}\left(\NVar{z}\right)$: Airy function, $\mathrm{Bi}\left(\NVar{z}\right)$: Airy function, $\mathscr{W}$: Wronskian, $\pi$: the ratio of the circumference of a circle to its diameter and $z$: complex variable Source: Olver (1997b, (1.19), p. 393) A&S Ref: 10.4.10 Referenced by: 9.10.2, 9.10.3, 9.11.2, 9.8.13, 9.8.17, 9.9.3, 9.9.4 Permalink: http://dlmf.nist.gov/9.2.E7 Encodings: TeX, pMML, png See also: Annotations for 9.2(iv), 9.2 and 9
9.2.8 $\mathscr{W}\left\{\mathrm{Ai}\left(z\right),\mathrm{Ai}\left(ze^{\mp 2\pi i/3}% \right)\right\}=\frac{e^{\pm\pi i/6}}{2\pi},$ ⓘ Symbols: $\mathrm{Ai}\left(\NVar{z}\right)$: Airy function, $\mathscr{W}$: Wronskian, $\pi$: the ratio of the circumference of a circle to its diameter, $\mathrm{e}$: base of natural logarithm and $z$: complex variable Source: Derivable from Olver (1997b, p. 416). A&S Ref: 10.4.11 10.4.12 Permalink: http://dlmf.nist.gov/9.2.E8 Encodings: TeX, pMML, png See also: Annotations for 9.2(iv), 9.2 and 9
9.2.9 $\mathscr{W}\left\{\mathrm{Ai}\left(ze^{-2\pi i/3}\right),\mathrm{Ai}\left(ze^{% 2\pi i/3}\right)\right\}=\frac{1}{2\pi i}.$ ⓘ Symbols: $\mathrm{Ai}\left(\NVar{z}\right)$: Airy function, $\mathscr{W}$: Wronskian, $\pi$: the ratio of the circumference of a circle to its diameter, $\mathrm{e}$: base of natural logarithm and $z$: complex variable Source: Derivable from Olver (1997b, p. 416). A&S Ref: 10.4.13 Permalink: http://dlmf.nist.gov/9.2.E9 Encodings: TeX, pMML, png See also: Annotations for 9.2(iv), 9.2 and 9
## §9.2(v) Connection Formulas
9.2.10 $\mathrm{Bi}\left(z\right)=e^{-\pi i/6}\mathrm{Ai}\left(ze^{-2\pi i/3}\right)+e% ^{\pi i/6}\mathrm{Ai}\left(ze^{2\pi i/3}\right).$ ⓘ Symbols: $\mathrm{Ai}\left(\NVar{z}\right)$: Airy function, $\mathrm{Bi}\left(\NVar{z}\right)$: Airy function, $\pi$: the ratio of the circumference of a circle to its diameter, $\mathrm{e}$: base of natural logarithm and $z$: complex variable Source: Derivable from Olver (1997b, p. 414). A&S Ref: 10.4.6 Referenced by: 9.10.19, 9.5.5 Permalink: http://dlmf.nist.gov/9.2.E10 Encodings: TeX, pMML, png See also: Annotations for 9.2(v), 9.2 and 9
9.2.11 $\mathrm{Ai}\left(ze^{\mp 2\pi i/3}\right)=\tfrac{1}{2}e^{\mp\pi i/3}\left(% \mathrm{Ai}\left(z\right)\pm i\mathrm{Bi}\left(z\right)\right).$ ⓘ Symbols: $\mathrm{Ai}\left(\NVar{z}\right)$: Airy function, $\mathrm{Bi}\left(\NVar{z}\right)$: Airy function, $\pi$: the ratio of the circumference of a circle to its diameter, $\mathrm{e}$: base of natural logarithm and $z$: complex variable Source: Olver (1997b, (8.04), p. 414) A&S Ref: 10.4.9 Permalink: http://dlmf.nist.gov/9.2.E11 Encodings: TeX, pMML, png See also: Annotations for 9.2(v), 9.2 and 9
9.2.12 $\mathrm{Ai}\left(z\right)+e^{-2\pi i/3}\mathrm{Ai}\left(ze^{-2\pi i/3}\right)+% e^{2\pi i/3}\mathrm{Ai}\left(ze^{2\pi i/3}\right)=0,$ ⓘ Symbols: $\mathrm{Ai}\left(\NVar{z}\right)$: Airy function, $\pi$: the ratio of the circumference of a circle to its diameter, $\mathrm{e}$: base of natural logarithm and $z$: complex variable Source: Olver (1997b, (8.03), p. 414) A&S Ref: 10.4.7 Permalink: http://dlmf.nist.gov/9.2.E12 Encodings: TeX, pMML, png See also: Annotations for 9.2(v), 9.2 and 9
9.2.13 $\mathrm{Bi}\left(z\right)+e^{-2\pi i/3}\mathrm{Bi}\left(ze^{-2\pi i/3}\right)+% e^{2\pi i/3}\mathrm{Bi}\left(ze^{2\pi i/3}\right)=0.$ ⓘ Symbols: $\mathrm{Bi}\left(\NVar{z}\right)$: Airy function, $\pi$: the ratio of the circumference of a circle to its diameter, $\mathrm{e}$: base of natural logarithm and $z$: complex variable Source: Derivable from Olver (1997b, p. 414). A&S Ref: 10.4.8 Permalink: http://dlmf.nist.gov/9.2.E13 Encodings: TeX, pMML, png See also: Annotations for 9.2(v), 9.2 and 9
9.2.14 $\displaystyle\mathrm{Ai}\left(-z\right)$ $\displaystyle=e^{\pi i/3}\mathrm{Ai}\left(ze^{\pi i/3}\right)+e^{-\pi i/3}% \mathrm{Ai}\left(ze^{-\pi i/3}\right),$ ⓘ Symbols: $\mathrm{Ai}\left(\NVar{z}\right)$: Airy function, $\pi$: the ratio of the circumference of a circle to its diameter, $\mathrm{e}$: base of natural logarithm and $z$: complex variable Source: Olver (1997b, p. 414) Permalink: http://dlmf.nist.gov/9.2.E14 Encodings: TeX, pMML, png See also: Annotations for 9.2(v), 9.2 and 9 9.2.15 $\displaystyle\mathrm{Bi}\left(-z\right)$ $\displaystyle=e^{-\pi i/6}\mathrm{Ai}\left(ze^{\pi i/3}\right)+e^{\pi i/6}% \mathrm{Ai}\left(ze^{-\pi i/3}\right).$
## §9.2(vi) Riccati Form of Differential Equation
9.2.16 $\frac{\mathrm{d}W}{\mathrm{d}z}+W^{2}=z,$ ⓘ Defines: $W$: Riccati solution (locally) Symbols: $\frac{\mathrm{d}\NVar{f}}{\mathrm{d}\NVar{x}}$: derivative of $f$ with respect to $x$ and $z$: complex variable Source: Derive properties using (9.2.1). Permalink: http://dlmf.nist.gov/9.2.E16 Encodings: TeX, pMML, png See also: Annotations for 9.2(vi), 9.2 and 9
$W=(1/w)\ifrac{\mathrm{d}w}{\mathrm{d}z}$, where $w$ is any nontrivial solution of (9.2.1). See also Smith (1990).
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https://forum.allaboutcircuits.com/threads/fourier-transform-of-an-time-integral.70273/
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# Fourier transform of an time integral
Discussion in 'Homework Help' started by epsilonjon, May 20, 2012.
1. ### epsilonjon Thread Starter Member
Feb 15, 2011
65
1
Question:
Derive the relationship
$\int^t_{- \infty} f(\tau) d \tau \Leftrightarrow \frac{F(\omega)}{j \omega} + \pi F(0) \delta (\omega)$
(where $\Leftrightarrow$ means "Fourier transforms into").
Attempt:
I have already proved the relationship
$\frac{dg(t)}{dt} \Leftrightarrow j \omega G( \omega)$
so define $h(t) = \frac{dg(t)}{dt}$. Then we have
$\int^t_{- \infty} h(\tau) d \tau = \int^t_{- \infty} \frac{dg}{d \tau} d \tau = [g(\tau)]^t_{- \infty} = g(t) - g(-\infty)$
so
$g(t) = \int ^t _{- \infty} h(\tau) d \tau + g(- \infty)$
Using the Fourier differentiation relationship above we get
$\mathcal{F}[h(t)] = j \omega \mathcal{F}[g(t)] = j \omega \mathcal{F} \left [ \int ^t _{- \infty} h(\tau) d \tau + g(- \infty) \right ] = j \omega \mathcal{F} \left [ \int ^t _{- \infty} h(\tau) d \tau \right ] + j \omega \mathcal{F}[g(- \infty)]$
$= j \omega \mathcal{F} \left [ \int ^t _{- \infty} h(\tau) d \tau \right ] + j \omega 2 \pi g(-\infty) \delta(\omega)$
so
$\mathcal{F} \left [ \int ^t _{- \infty} h(\tau) d \tau \right ] = \frac{\mathcal{F}[h(t)]}{j \omega} - 2 \pi g(-\infty) \delta(\omega)$
I'm not sure if i've done something wrong here or if somehow this is equivalent to the correct relationship? Could someone help please
Thanks!
Jon.
Last edited: May 21, 2012
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https://figshare.shef.ac.uk/articles/dispersion_m_-_A_MatLab_script_for_phase_angle_and_amplitude_correction_of_pressure_bar_signals/3996876/1
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## dispersion.m - A MatLab script for phase angle and amplitude correction of pressure bar signals
2016-10-12T12:04:38Z (GMT)
In processing the signals from split Hopkinson pressure bar (SHPB) experiments it is often assumed that longitudinal stress waves in the pressure bars propagate one-dimensionally at a common velocity c_0, and so measurements taken at the strain gauges are often simply translated to the end of the bar using a suitable time delay. In reality, stress waves propagate at a specific phase velocity, c_p, which is a function of frequency and the bar's diameter, one-dimensional wave speed and Poisson's ratio. Phase velocity decreases as the frequency of a wave increases, leading to dispersion of a signal as it propagates down the bar. Dispersion of the stress pulse is accompanied by a frequency-dependent variation in stress and strain across the bar cross-section, so that a signal recorded on the surface of the bar at some distance from the specimen will not accurately describe the stresses the specimen was subjected to, and hence cannot be used to accurately determine the specimen response.<p>This script uses an implementation of the dispersion-correction method described by Tyas and Pope (2005) to ensure that the inferred measurements of axial stress and strain accurately represent the specimen behaviour. In this method:</p><ol><li>The time-domain strain signal is converted into the frequency domain using the fast Fourier transform (FFT)</li><li>A correction is applied to the phase angle of each frequency component to account for the dispersion over the distance between the strain gauge and the bar end, using Bancroft's equation.</li><li>A correction is applied to the amplitude of each frequency component using the factors M_1 and M_2, which account for the variation of strain and Young's modulus across the bar cross section, respectively. These are derived from Davies' analysis of the radial effects in a cylindrical pressure bar.</li><li>The signal is transformed back into the time domain using the inverse FFT.</li></ol><p>Dispersion.m uses a pre-calculated, normalised look-up table of phase velocity, M1 and M2 to improve calculation time. A lookup table for a Poisson's ratio of 0.29 has been provided in the .zip file, and other tables can be constructed using the relationships defined in Tyas and Pope (2005).<br></p><p><br></p><p>Further information on the operation of the script is also available in Barr (2016), linked below.</p>
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https://www.ideals.illinois.edu/handle/2142/107539
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## Files in this item
FilesDescriptionFormat
application/pdf
4619.pdf (18kB)
AbstractPDF
## Description
Title: A SEARCH FOR LIGHT HYDRIDES IN THE ENVELOPES OF EVOLVED STARS Author(s): Siebert, Mark A. Contributor(s): Burkhardt, Andrew M; Shingledecker, Christopher N; McGuire, Brett A.; Remijan, Anthony Subject(s): Astronomy Abstract: The circumstellar envelopes of asymptotic giant branch (AGB) and red supergiant (RSG) stars are known for their unique chemistry and efficient production of dust grains. Though dust grain composition and behavior at micron-size is well-studied in the ISM, the chemical processes leading to their formation are poorly understood from an observational lens. Thus, characterizing the reservoir of gas-phase molecules in the Dust Production Zones" of evolved stellar envelopes (5--20 R*) is crucial to understanding the process of grain condensation. Thermochemical equilibrium models predict that a variety of light hydrides (XH) are abundant in these regions; however, only three such species have been observed in CSEs to-date (HCl, HF, and OH). Using SOFIA's GREAT receiver, we conducted a search for the diatomic hydrides SiH and PH toward two well-studied circumstellar envelopes: IRC+10216 and VY CMa. We present spectra for these objects ranging from 600 GHz to 1.5 THz, where most ro-vibrational emission comes from highly excited molecules near the stellar photosphere. Neither SiH nor PH were detected in these envelopes, likely owing to their weak dipole moments and severe beam dilution expected from molecules in the inner envelope. We calculated upper limit abundances for SiH and PH in IRC+10216 and VY CMa and discuss their implications for equilibrium chemistry and dust grain formation theories in these important astronomical laboratories. Issue Date: 24-Jun-20 Publisher: International Symposium on Molecular Spectroscopy Citation Info: APS Genre: CONFERENCE PAPER/PRESENTATION Type: Text Language: English URI: http://hdl.handle.net/2142/107539 Date Available in IDEALS: 2020-06-26
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https://worldwidescience.org/topicpages/d/digital+subtraction+angiogram.html
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#### Sample records for digital subtraction angiogram
1. Digital subtraction laryngography
Brown, B.W.; Enzmann, D.R.; Hopp, M.L.; Castellino, R.A.
1983-06-01
Digital subtraction laryngography was used to evaluate laryngeal function in 8 patients: 4 with normal larynxes and 4 with laryngeal disease. Subtracted digital images provided a dynamic display of the extent and symmetry of vocal cord excursions and pyriform sinus inflation, and the vocal cord resting position was also clearly depicted. The technical details of digital subtraction laryngography and its application are described.
2. Digital image processing of vascular angiograms
Selzer, R. H.; Beckenbach, E. S.; Blankenhorn, D. H.; Crawford, D. W.; Brooks, S. H.
1975-01-01
The paper discusses the estimation of the degree of atherosclerosis in the human femoral artery through the use of a digital image processing system for vascular angiograms. The film digitizer uses an electronic image dissector camera to scan the angiogram and convert the recorded optical density information into a numerical format. Another processing step involves locating the vessel edges from the digital image. The computer has been programmed to estimate vessel abnormality through a series of measurements, some derived primarily from the vessel edge information and others from optical density variations within the lumen shadow. These measurements are combined into an atherosclerosis index, which is found in a post-mortem study to correlate well with both visual and chemical estimates of atherosclerotic disease.
3. Clinical and radiological of acute ischemic stroke patients without angiographic occlusion on digital subtraction angiogram. A pooled analysis of case series
Shah, Qaisar A.; Memon Zeeshan, Muhammad; Vazquez, Gabriela; Suri, M. Fareed K.; Hussein, Haitham M.; Qureshi, Adnan I. [Zeenat Qureshi Stroke Research Center, Department of Neurology, University of Minnesota, Minneapolis, MN (United States); Mohammad, Yousef M. [Department of Neurology, Ohio State University, Columbus, OH (United States)
2008-11-15
Approximately 20-30% of the patients with acute ischemic stroke do not have any occlusion demonstrated on initial digital subtraction angiography (DSA). We sought to determine the risk and rates of cerebral infarction and favorable neurological outcome in this group of acute ischemic stroke patients. Patients were identified from a prospectively maintained stroke database and from literature search of MEDLINE, PubMed, and Cochrane databases. All patients had initial neurological assessment on National Institutes of Health Stroke Scale (NIHSS). Patients then underwent DSA after initial head computed tomography (CT) scans. Follow-up radiological assessment at 24-72 h was performed with CT and magnetic resonance imaging scans. Association of stroke risk factors with clinical and radiological outcomes was estimated. A total of 81 patients was analyzed (mean age 63 years; 28 were women). The median NIHSS score was 8 (range 2-25). None of the patients received either intravenous or intra-arterial thrombolytic. Cerebral infarction was detected in 62 (76%) of the 81 patients. Twenty-four to 48-h NIHSS was available for 51 patients only. Neurological improvement was observed in 22 (43%) of the 51 patients. Favorable outcome ascertained at 3-month follow-up was seen in 48 (59%) of the 81 patients. After adjusting for age, sex, and baseline NIHSS, male patients [odds ratio (OR) 4.5 (1.4-14.3), p value=0.01] and patients with age{>=} =65 [OR 4.3 (1.2-16.2), p value=0.03] have a higher risk of cerebral infarcts on the follow-up imaging. Similarly, patients who presented with <10 NIHSS had a better 3-month outcome than those with >10 NIHSS [OR 0.21 (0.08-0.61), p value=0.004]. Ischemic stroke patients without arterial occlusion on DSA have a higher risk of cerebral infarction and disability particularly in men, patients over 65 years of age and with NIHSS{>=}=10. The cause of infarction may have been arterial obstruction with spontaneous recanalization or small vessel occlusion
4. Digital subtraction angiography of the thoracic aorta
Grossman, L.B.; Buonocore, E.; Modic, M.T.; Meaney, T.F.
1984-02-01
Forty-three patients with acquired and congenital abnormalities of the thoracic aorta were studied using digital subtraction angiography (DSA) after an intravenous bolus injection of 40 ml of contrast material. Abnormalities studied included coarctation, pseudocoarctation, Marfan syndrome, cervical aorta, double aortic arch, aneurysm, dissection, and tumor. Twenty-four patients also had conventional angiography. DSA was accurate in 95% of cases; in the other 5%, involving patients with acute type I dissection, the coronary arteries could not be seen. The authors concluded that in 92% of their patients, DSA could have replaced the standard aortogram.
5. Coherent bremsstrahlung used for digital subtraction angiography
Überall, Herbert
2007-05-01
Digital subtraction angiography (DSA), also known as Dichromography, using synchrotron radiation beams has been developed at Stanford University (R. Hofstadter) and was subsequently taken over at the Brookhaven Synchrotron and later at Hamburg (HASYLAB) [see, e.g., W.R. Dix, Physik in unserer Zeit. 30 (1999) 160]. The imaging of coronary arteries is carried out with an iodine-based contrast agent which need not be injected into the heart. The radiation must be monochromatized and is applied above and below the K-edge of iodine (33.16 keV), with a subsequent digital subtraction of the two images. Monochromatization of the synchrotron radiation causes a loss of intensity of 10 -3. We propose instead the use of coherent bremsstrahlung [see, e.g., A.W. Saenz and H. Uberall, Phys. Rev. B25 (1982) 448] which is inherently monochromatic, furnishing a flux of 10 12 photon/sec. This requires a 10-20 MeV electron linac which can be obtained by many larger hospitals, eliminating the scheduling problems present at synchrotrons. The large, broad incoherent bremsstrahlung background underlying the monochromatic spike would lead to inadmissible overexposure of the patient. This problem can be solved with the use of Kumakhov's capillary optics [see e.g., S.B.Dabagov, Physics-Uspekhi 46 (2003) 1053]: the low-energy spiked radiation can be deflected towards the patient, while the higher energy incoherent background continues forward, avoiding the patient who is placed several meters from the source.
6. Use of digital subtraction angiography for assessment of digital replantatlon
Liu-hong WANG; Guang-qiang ZHANG
2012-01-01
Objective:To assess the blood flow of the proper digital artery using digital subtraction angiography (DSA) in the early stage after replantation.Methods:From January 2006 to October 2010,27 anastomosed arteries in 27 replanted digits were included in the study.The patients included nine males and four females.The patients received DSA at 48 to 96 h after digital replantation.Based on DSA image,the blood flow was classified into normal,slow-running,and flow-stopping types.The patients with normal digital blood flow were given continuous routine treatments; the patients with slow-running flow were given the conservative treatments,such as release of the tight dressings,removal of stitches,keeping warm,the use of massage,and the use of anticoagulants and anti-inflammatory drugs; the patients with flow-stopping received immediate surgical re-exploration.Results:In this series,23 digits in 11 patients showed a normal blood flow,and these digits all survived.In one of 13 patients,two digits which displayed slow-running flow also survived after conservative treatments.In two of 13 patients,two digits showed flow stopping,with one surviving and one failing after re-exploration and arterial revision.Conclusions:The DSA can be used to assess the blood flow of the proper digital artery in the early stage after replantation.It provides essential information for salvaging the replanted finger.
7. Digital contrast subtraction radiography for proximal caries diagnosis
Kang, Byung Cheol; Yoon, Suk Ja [Department of Dental Radiology, Chonnam National University Hospital, Gwangju (Korea, Republic of)
2002-06-15
8. Digital subtraction angiography in cerebral infarction
Cho, Sin Young; Kim, Ji Hun; Suh, Hong Kil; Kim, Hyo Heon; Kwack, Eun Young; Lee, Il Seong [College of Medicine Hallym University, Seoul (Korea, Republic of)
1995-01-15
The usefulness and radiographic findings of the angiography in cerebral infarction are well known. We attempted to evaluate the angiographic causes, findings, and the usefulness of DSA in cerebral infarction. The authors reviewed retrospectively DSA images of 51 patients who were diagnosed as having cerebral infarction by brain CT and/or MRI and clinical settings. DSA was performed in all 51 patients, and in 3 patients, conventional angiogram was also done. Both carotid DSA images were obtained in AP, lateral, oblique projections, and one or both vertebral DSA images in AP and lateral. The authors reviewed the patient's charts for symptoms, operative findings and final diagnosis, and analysed DSA findings of cerebral atherosclerosis with focus on 6 major cerebral arteries. Among the 51 patients of cerebral infarction 43 patients (84.3%) had cerebral atherosclerosis, 1 dissecting aneurysm, 1 moyamoya disease and 6 negative in angiogram. DSA findings of cerebral atherosclerosis were multiple narrowing in 42 patients (97.7%), tortuosity in 22 (51.2%), dilatation in 14, occlusion in 12, avascular region in 8, collaterals in 7, ulcer in 6, and delayed washout of contrast media in 3. In cerebral atherosclerosis, internal carotid artery was involved in 37 patients (86.0%), middle cerebral artery in 29 (67.4%) posterior cerebral artery in 28, anterior cerebral artery in 26, vertebral artery in 22, and basilar artery in 15. Intracranial involvement of cerebral atherosclerosis (64.9%) was more common than extracranial involvement (16.2%). In cerebral infarction MRA may be the screening test, but for more precise evaluation of vascular abnormality and its extent, DSA should be considered.
9. Carbon dioxide digital subtraction angiography in percutaneous sclerotherapy of venous hemangiomas
Park, Jae Hyung; Chung, Jin Wook; Kang, Heung Sik; Han, Man Chung [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)
1997-08-01
To investigate the usefulness of carbon dioxide digital subtraction angiography (CO{sub 2}-DSA) in direct puncture sclerotherapy of venous hemangiomas involving extremities. Direct puncture sclerotherapy was performed in 12 patients with venous hemangioma of extremities. After direct puncture of the venous hemangiomas, 30-50cc of CO{sub 2} was manually injected and digital subtraction angiograms were obtained. If draining vein was visualized, a tourniquet was applied at the proximal site to compress the draining veins. Thereafter, radiopaque embolic materials such as 1:3 mixture of Lipiodol and absolute ethanol or ethanolamine oleate-Lipiodol-Avitene(microfibrillar collagen hemostat) mixture were slowly injected under the fluoroscopic guidance. Rapid injection of large amount of CO{sub 2} enabled the visualization of wide areas of venous hemangiomas in 11 patients. Draining veins were reliably demonstrated in 10 patients and pulmonary embolism of embolic materials was effectively prevented by proximal tourniquet application. Because of radiolucent nature of CO{sub 2} retained in hemangiomas, we could clearly identify the distribution of radiopaque embolic materials under fluoroscopy. Retained CO{sub 2} also could be used as a guide for additional multiple puncture of hemangiomas. There was no systemic symptoms or complications related to CO{sub 2}-DSA. CO{sub 2}-DSA is a convenient, safe and useful angiographic technique in direct puncture sclerotherapy of hemangiomas involving extremities.
10. Peripheral Angiogram
... any medicines (including over-the-counter, herbs and vitamins) you take. He or she may ask you ... I need a procedure to open up or bypass any blocked arteries? Learn more: Atherosclerosis Coronary Angiogram ...
11. Digital subtraction angiography in pediatric cerebrovascular occlusive disease
Faerber, E.N.; Griska, L.A.B.; Swartz, J.D.; Capitanio, M.A.; Popky, G.L.
1984-08-01
While conventional angiography has been used to demonstrate cerebrovascular occlusive disease in the past, digital subtraction angiography (DSA) is capable of showing progressive vascular involvement with ease, simplicity, and extremely low morbidity, making it particularly well suited for children and outpatients either alone or coordinated with computed tomography. The authors discuss the usefulness and advantages of DSA as demonstrated in 7 infants and children with hemiplegia, 4 of whom had sickle-cell disease.
12. Multi-section CT angiography compared with digital subtraction angiography in diagnosing major arterial hemorrhage in inflammatory pancreatic disease
Hyare, Harpreet [Department of Imaging, University College London Hospitals NHS Foundation Trust, University College Hospital, 235 Euston Road, London NW1 2BU (United Kingdom)]. E-mail: [email protected]; Desigan, Sharmini [Department of Imaging, University College London Hospitals NHS Foundation Trust, University College Hospital, 235 Euston Road, London NW1 2BU (United Kingdom); Nicholl, Helen [Department of Imaging, University College London Hospitals NHS Foundation Trust, University College Hospital, 235 Euston Road, London NW1 2BU (United Kingdom); Guiney, Michael J. [Department of Imaging, University College London Hospitals NHS Foundation Trust, University College Hospital, 235 Euston Road, London NW1 2BU (United Kingdom); Brookes, Jocelyn A. [Department of Imaging, University College London Hospitals NHS Foundation Trust, University College Hospital, 235 Euston Road, London NW1 2BU (United Kingdom); Lees, William R. [Department of Imaging, University College London Hospitals NHS Foundation Trust, University College Hospital, 235 Euston Road, London NW1 2BU (United Kingdom)
2006-08-15
Purpose: Major arterial hemorrhage is an uncommon but serious complication of pancreatitis with high morbidity and mortality. Digital subtraction angiography (DSA) has long been the gold standard for the detection of a visceral artery pseudoaneurysm or for the site of active bleeding in patients with pancreatitis. Multi-section CT angiography is a minimally invasive technique which can provide high-resolution and high-contrast images of the arterial lumen and wall, with a much lower risk of complication and morbidity compared to DSA. The aim of this study was to determine the accuracy of multi-section CT angiography for the diagnosis of arterial complications of inflammatory pancreatitic disease. Materials and methods: A retrospective analysis of all patients undergoing visceral angiography for major bleeding as a complication of pancreatitis between 1998 and 2004 was performed. Twenty-nine studies in 25 patients (20 males, 5 females) with a mean age of 50.9 years (range 11-67 years) were identified where multi-section CT angiography was performed in the 24 h preceding the digital subtraction angiogram. Results: Digital subtraction angiography detected a pseudoaneurysm or contrast extravasation in 19 studies and no bleeding was demonstrated in 9 studies. CT angiography correctly identified the site and type of bleeding in 18 of the 19 positive studies. CT angiography detected extravasation of contrast in one study that was not demonstrated on digital subtraction angiography. The sensitivity and specificity for multi-section CT angiography for the detection of major arterial bleeding on a background of pancreatitis were 0.947 and 0.900, respectively. Conclusion: Multi-section CT angiography is a sensitive and accurate technique for the detection of major arterial hemorrhage in inflammatory pancreatic disease and should be considered as the first investigation in the management of these patients.
Carmody, R.F.; Seeger, J.F.; Smith, R.L.; Horsley, W.W.; Miller, R.W.
1984-07-01
Intravenous digital subtraction angiography (IVDSA) was used to evaluate 44 patients with suspected otolaryngologic abnormalities. Sixteen had IVDSA for pulsatile tinnitus or suspected glomus tumor of the petrous bone. Nine patients were evaluated because of pulsatile neck masses, and 12 others had suspected tumors of the neck, face, and paranasal sinuses. Seven had IVDSA following head and neck trauma. The technique of examination is described. The current indications of IVDSA in head and neck radiology are discussed. It is concluded that IVDSA is a suitable substitute for conventional angiography for many otolaryngologic conditions and, because of its safety, can be used more liberally.
14. Developmental venous anomalies: appearance on whole-brain CT digital subtraction angiography and CT perfusion
2011-05-15
Developmental venous anomalies (DVA) consist of dilated intramedullary veins that converge into a large collecting vein. The appearance of these anomalies was evaluated on whole-brain computed tomography (CT) digital subtraction angiography (DSA) and CT perfusion (CTP) studies. CT data sets of ten anonymized patients were retrospectively analyzed. Five patients had evidence of DVA and five age- and sex-matched controls were without known neurovascular abnormalities. CT angiograms, CT arterial-venous views, 4-D CT DSA and CTP maps were acquired on a dynamic volume imaging protocol on a 320-detector row CT scanner. Whole-brain CTP parameters were evaluated for cerebral blood flow (CBF), cerebral blood volume (CBV), time to peak (TTP), mean transit time (MTT), and delay. DSA was utilized to visualize DVA anatomy. Radiation dose was recorded from the scanner console. Increased CTP values were present in the DVA relative to the unaffected contralateral hemisphere of 48%, 32%, and 26%; and for the control group with matched hemispheric comparisons of 2%, -10%, and 9% for CBF, CBV, and MTT, respectively. Average effective radiation dose was 4.4 mSv. Whole-brain DSA and CTP imaging can demonstrate a characteristic appearance of altered DVA hemodynamic parameters and capture the anomalies in superior cortices of the cerebrum and the cerebellum. Future research may identify the rare subsets of patients at increased risk of adverse outcomes secondary to the altered hemodynamics to facilitate tailored imaging surveillance and application of appropriate preventive therapeutic measures. (orig.)
15. The Principle of Digital Subtraction Angiography and Radiological Protection
Okamoto, K.; Ito, J.; Sakai, K.; Yoshimura, S.
2000-01-01
Summary Recent improvements in x-ray technology have greatly contributed to the advancement of diagnostic imaging. Fluoroscopically guided neurointerventional procedures with digital subtraction angiography (DSΛ) are being performed with increasing frequency as the treatment of choice for a variety of neurovascular diseases. Radiation-induced skin injuries can occur after extended fluoroscopic exposure times, and the injuries have recently been reported. In this article, measured radiation doses at the surface of Rando Phantom with Skin Dose Monitor, and estimated and measured entrance skin doses in patients underwent neurointerventional procedures are reported as well as means of reducing radiation doses absorbed by patients and personnel to avoid occurrence of radiation-induced injuries. PMID:20667218
16. Gadobutrol: an alternative contrast agent for digital subtraction dacryocystography
Priebe, M.; Mohr, A.; Brossmann, J.; Heller, M.; Frahm, C. [Department of Diagnostic Radiology, Christian-Albrechts-University of Kiel, Arnold-Heller-Strasse 9, 24105 Kiel (Germany)
2002-08-01
17. Value of intravenous digital subtraction angiography for amaurosis fugax
Horio, Shunji; Uchida, Sunao
1987-07-01
We performed intravenous digital subtraction angiography (IVDSA) in 12 cases of amaurosis fugax to evaluate the arteries in the head and neck region. We could detect stenosis or irregularity in the arterial wall in 5 cases (46 %). These 5 cases were treated with surgical or medical antiplatelet therapy. Amaurosis fugax disappeared in all treated cases. We also performed IVDSA in 11 cases with obstructive retinal vascular diseases. Stenosis of internal carotid artery was detected in one case (9 %). IVDSA proved thus to be of value in detecting abnormalities of carotid artery and its tributaries. While it is unlikely that IVDSA will replace conventional intraarterial angiography, IVDSA is much safer than direct arterial puncture and does not require admission in hospital.
18. Diagnosis of carotid body tumor by digital subtraction angiography
戚跃勇; 邹利光; 孙清荣; 徐健; 周政; 谭颖徽
2004-01-01
Objective: To make a further understanding of the features of the carotid body tumor (CBT) by digital subtraction angiography (DSA) so as to explore the clinical value of DSA diagnosis and interventional therapy for CBT. Methods: DSA data from 12 cases of CBT were analyzed retrospectively. A consensus interpretation of the DSA appearances in all of the patients was reached after dynamic observation by 2 experienced radiologists in a double-blind manner. Results: Definite diagnosis in all cases could be made by DSA. The DSA features of the CBT included bigger bifurcation angles of the internal and external carotid arteries, displacement of internal and external carotid arteries, CBT supplied by external carotid arteries in most cases and the significant increase of tumor blood vessels in bifurcation. Invasion of internal or external carotid arteries was found in 6 cases. Smaller stained area of the tumor and significantly reduced intraoperative bleeding were found after embolization of the supplying arteria in 2 cases. Conclusion: DSA is the effective method for the diagnosis and preoperative assessment of CBT. Preoperative embolization of CBT may contribute to the reduced intraoperative bleeding.
19. The concept of apparent cardiac arrest as a prerequisite for coronary digital subtraction angiography
Werf, T. van der; Heethaar, R.M.; Stegehuis, H.; Meijler, F.L.
1984-01-01
This study was undertaken to evaluate the possible use of digital subtraction applied after selective coronary arteriography. An identical position of the objects with and without contrast medium is an absolute requirement for the application of subtraction techniques. Because coronary arteries are
20. Digital subtraction angiography of the cerebral vessels by intraarterial injection
Nagata, Izumi; Kikuchi, Haruhiko; Karasawa, Jun; Mitsugi, Toru; Naruo, Yoshito; Takamiya, Makoto (National Cardiovascular Center, Suita, Osaka (Japan))
1984-10-01
Three hundred and fifty-seven digital subtraction angiography (DSA) were performed in 184 neurosurgical patients by intraarterial injection. Examinations consisted of 192 carotid angiography, 110 vertebral angiography, 23 aortography, 11 spinal angiography and 21 other angiography. In all examinations, visualization of the vessels was excellent and the complications were never experienced. High contrast sensitivity of DSA resulted in better visualization of tumor stains, phlebogram, and arteries in cerebral arteriovenous malformations with large shunt blood flow than conventional angiography. Selective catheterization into each cerebral arteries was not necessarily demanded for good opacification of the vessels because of high sensitivity. High contrast sensitivity also permitted low concentration of contrast material, small dose of contrast material, and slow injection rate. Low concentration of contrast material reduced pain and heat during injection especially in the external carotid and vertebral angiography. Using slow injection, recoiling of catheter into the aorta was reduced, so that injection from the innominate and subclavian arteries for visualization of origin of the cerebral arteries were always successful. Full study of cerebral arteries by Seldinger's method, if necessary, was easily achieved using DSA even in patient with high age or with severe atherosclerosis. Bolus injection of small dose of contrast material as well as serial imaging was helpful in evaluating hemodynamics in the lesion. Real time display of DSA reduced the time required for angiography and was very convenient for artificial embolization. Besides these advantages, DSA became comparable to conventional angiography in spacial resolution by use of intraarterial injection and could be a preoperative genuine examination as well as a screening method.
1. Proximal caries detection using digital subtraction radiography in the artificial caries activity model
Park, Jong Hoon; Lee, Gi Ja; Choi, Sam Jin; Park, Young Ho; Kim, Kyung Soo; Jin, Hyun Seok; Hong, Kyung Won; Oh, Berm Seok; Park, Hun Kuk [Department of Biomedical Engineering, School of Medicine, Kyung Hee University, Seoul (Korea, Republic of); Choi, Yong Suk; Hwang, Eui Hwan [Department of Oral and Maxillofacial Radiology, Institute of Oral Biology, School of Dentistry, Kyung Hee University, Seoul (Korea, Republic of)
2009-03-15
The purpose of the experiment was to evaluating the diagnostic ability of dental caries detection using digital subtraction in the artificial caries activity model. Digital radiographs of five teeth with 8 proximal surfaces were obtained by CCD sensor (Kodak RVG 6100 using a size no.2). The digital radiographic images and subtraction images from artificial proximal caries were examined and interpreted. In this study, we proposed novel caries detection method which could diagnose the dental proximal caries from single digital radiographic image. In artificial caries activity model, the range of lesional depth was 572-1,374 {mu}m and the range of lesional area was 36.95-138.52 mm{sup 2}. The lesional depth and the area were significantly increased with demineralization time (p<0.001). Furthermore, the proximal caries detection using digital subtraction radiography showed high detection rate compared to the proximal caries examination using simple digital radiograph. The results demonstrated that the digital subtraction radiography from single radiographic image of artificial caries was highly efficient in the detection of dental caries compared to the data from simple digital radiograph.
2. Clinical evaluation of intravenous digital subtraction angiography in chest diseases in the elderly
Yamamoto, Kazuhide; Adachi, Satoru; Suzuki, Kanzo and others
1988-01-01
To evaluate the image quality, we performed intravenous digital subtraction angiography for various chest diseases in 62 elderly subjects. In large vessel diseases in the chest, adequate imaging was possible in most cases, especially in the main, right and left pulmonary artery and the aorta. However, second order (subsegmental) and more distal order branches were sometimes judged unsatisfactory because of poor image quality. Five cases were evaluated as inadequate because of motion, i.e. respiratory or cardiac movement. The pulmonary circulating time was measured by the time density curve of the pulmonary artery and vein by digital subtraction angiography, and converse correlation between pulmonary circulating time and cardiac index was obtained. Thus it was possible to evaluate the pulmonary circulating dynamics. As mentioned above, intravenous digital subtraction angiography was a useful and safe method for chest diseases, especially in evaluation of large vessels in the elderly.
3. Titanium plate artefact mimicking popliteal artery dissection on digital subtraction CT angiography.
Woodacre, Timothy; Wienand-Barnett, Sophie
2013-04-05
Titanium plates used for the internal fixation of long bone fractures cause significant artefact on CT scans but have not been reported to affect digital subtraction CT angiography. We present a patient with clinical suspicion of popliteal artery injury following a high tibial osteotomy. The osteotomy was stabilised with a titanium locking plate. During the digital subtraction process used to produce reconstruction CT angiography, removal of artefact caused by the titanium plate produced CT images mimicking the appearance of a popliteal artery dissection. The imaging inaccuracy was realised prior to the patient undergoing further intervention. We highlight the potential error caused by titanium plates on digital subtraction CT angiography and recommend careful analysis of such images prior to further treatment.
4. Procedures for imaging of hemodialysis fistulas with particular reference to digital subtraction angiography (DSA)
Neufang, K.F.R.; Erasmi-Koerber, H.; Wimmer, G.
1983-05-01
All angiographic procedures established for imaging of hemodialysis fistulas, such as direct venous angiography, intravenous subtraction angiography and arteriography by direct puncture of the brachial artery by Seldinger's transfemoral technique, can also be effected with digital image processing. Depending on the angiographic technique, the use of digital subtraction angiography has several advantages: lower doses and concentrations of the contrast agent, lower risk of complications (thrombosis of the fistula, vasospasm) and freedom from pain. In addition, there is a marked reduction of examination time and film cost.
5. Suppression of DC term in Fresnel digital holography by sequence subtraction of holograms
Kang, Jong-Chol; Im, Song-Jin
2016-01-01
An experimental method for suppression of DC term in the reconstructed images from Fresnel digital holograms is presented. In this method, two holograms for the same object are captured sequentially and subtracted. Since these two holograms are captured at different moments, they are slightly different from each other for fluctuations of noises. The DC term is suppressed in the image reconstructed from the subtraction hologram, while the two virtual and real images are successfully reconstructed. This method can be potentially used for the improvement of image quality reconstructed from Fresnel digital holograms.
6. Acquisition-related motion compensation for digital subtraction angiography.
Ionasec, Razvan Ioan; Heigl, Benno; Hornegger, Joachim
2009-06-01
Subtraction methods in angiography are generally applied in order to enhance the visualization of blood vessels by eliminating bones and surrounding tissues from X-ray images. The main limitation of these methods is the sensitivity to patient movement, which leads to artifacts and reduces the clinical value of the subtraction images. In this paper we present a novel method for rigid motion compensation with primary application to road mapping, frequently used in image-guided interventions. Using the general concept of image-based registration, we optimize the physical position and orientation of the C-arm X-ray device, thought of as the rigid 3D transformation accounting for the patient movement. The registration is carried out using a hierarchical optimization strategy and a similarity measure based on the variance of intensity differences, which has been shown to be most suitable for fluoroscopic images. Performance evaluation demonstrated the capabilities of the proposed approach to compensate for potential intra-operative patient motion, being more resilient to the fundamental problems of pure image-based registration.
7. Role of digital tomosynthesis and dual energy subtraction digital radiography in detecting pulmonary nodules
Kumar, Sarvana G. [Department of Radiodiagnosis and Imaging, Postgraduate Institute of Medical Education and Research (PGIMER), Sector 12, Chandigarh 160012 (India); Garg, Mandeep Kumar, E-mail: [email protected] [Department of Radiodiagnosis and Imaging, Postgraduate Institute of Medical Education and Research (PGIMER), Sector 12, Chandigarh 160012 (India); Khandelwal, Niranjan; Gupta, Pankaj [Department of Radiodiagnosis and Imaging, Postgraduate Institute of Medical Education and Research (PGIMER), Sector 12, Chandigarh 160012 (India); Gupta, Dheeraj; Aggarwal, Ashutosh Nath [Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research (PGIMER), Sector 12, Chandigarh 160012 (India); Bansal, Subash Chand [Department of Radiodiagnosis and Imaging, Postgraduate Institute of Medical Education and Research (PGIMER), Sector 12, Chandigarh 160012 (India)
2015-07-15
Highlights: • Accuracy of digital tomosynthesis for nodule detection is substantially higher. • Improvement in diagnostic accuracy is most pronounced for nodules <10 mm. • There is five times increase in radiation dose compared to DR. - Abstract: Objective: Digital tomosynthesis (DT) and dual-energy subtraction digital radiography (DES-DR) are known to perform better than conventional radiography in the detection of pulmonary nodules. Yet the comparative diagnostic performances of DT, DES-DR and digital radiography (DR) is not known. The present study compares the diagnostic performances of DT, DES-DR and DR in detecting pulmonary nodules. Subjects and methods: The institutional Review Board approved the study and informed written consent was obtained. Fifty-five patients (30 with pulmonary nodules, 25 with non-nodular focal chest pathology) were included in the study. DT and DES-DR were performed within14 days of MDCT. Composite images acquired at high kVp as part of DES-DR were used as DR images. Images were analyzed for presence of nodules and calcification in nodules. Interpretations were assigned confidence levels from 1 to 5 according to Five-Point rating scale. Areas under the receiver operating characteristic curves were compared using Z test. Results: A total of 110 (88 non-calcified, 22 calcified) nodules were identified on MDCT. For detection of nodules, DR showed cumulative sensitivity and specificity of 25.45% and 67.97%, respectively. DT showed a cumulative sensitivity and specificity of 60.9% and 85.07%, respectively. The performance was significantly better than DR (p < 0.003). DES-DR showed sensitivity and specificity of 27.75% and 82.64%, not statistically different from those of DR (p—0.92). In detection of calcification, there was no statistically significant difference between DT, DES-DR and DR. Conclusions: DT performs significantly better than DES-DR and DR at the cost of moderate increase in radiation dose.
8. Digital subtraction cystography for detection of communicating holes of spinal extradural arachnoid cysts
Gu, Kyo Won; Kwon, Jong Won; Kim, Eun Sang [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)
2016-02-15
The purpose of this study was to demonstrate the usefulness of digital subtraction cystography to identify communicating holes between a spinal extradural arachnoid cyst (SEAC) and the subarachnoid space prior to cyst removal and hole closure. Six patients with SEAC were enrolled in this retrospective study. Digital subtraction cystography and subsequent CT myelography were performed for every patient. The presence and location of the communicating holes on cystography were documented. We evaluated the MRI characteristics of the cysts, including location, size, and associated spinal cord compression; furthermore, we reviewed cystographic images, CT myelograms, procedural reports, and medical records for analysis. If surgery was performed after cystography, intraoperative findings were compared with preoperative cystography. The location of the communicating hole between the arachnoid cyst and the subarachnoid space was identified by digital subtraction cystography in all cases (n = 6). Surgical resection of SEAC was performed in 4 patients, and intraoperative location of the communicating hole exactly corresponded to the preoperative identification. Fluoroscopic-guided cystography for SEAC accurately demonstrates the presence and location of dural defects. Preoperative digital subtraction cystography is useful for detection of a communicating hole between a cyst and the subarachnoid space.
9. Digital subtraction angiography and intraarterial contrast medium injection for coronary examinations
Tobio, R.; Kallmeyer, C.; Castello, J.
1985-01-01
Digital subtraction angiography (DSA) is an established method of vasography, most extensively used as i.v. DSA. Intraarterial injection, however, applying selective or non-selective contrast medium injection, seems to be at least as important a technique although it has not yet met with corresponding interest. The article explains advantages of the technique for angiographic examinations, in particular of coronary angiography.
10. [The improved design of table operating box of digital subtraction angiography device].
Qi, Xianying; Zhang, Minghai; Han, Fengtan; Tang, Feng; He, Lemin
2009-12-01
In this paper are analyzed the disadvantages of CGO-3000 digital subtraction angiography table Operating Box. The authors put forward a communication control scheme between single-chip microcomputer(SCM) and programmable logic controller(PLC). The details of hardware and software of communication are given.
11. Digital subtraction angiography for tumours of the ear, nose and throat
Langer, M.; Zwicker, C.; Eichstaedt, H.; Maeurer, J.
1986-08-01
Intravenous and intra-arterial digital subtraction angiography is able to demonstrate hypervascular tumours in the ear, nose and throat territory. Direct puncture of a venous bypass used for intra-arterial chemotherapy, within the external carotid artery territory, is devoid of risk and can be used for assessing the accessibility of the tumour. Lesions of low vascularity can only be recognised by DSA on the basis of vessel displacement. These lesions are not a primary indication for examination by digital angiography. (orig).
12. Digital subtraction peripheral angiography using image stacking: initial clinical results.
Kump, K S; Sachs, P B; Wilson, D L
2001-07-01
Using clinically acquired x-ray angiography image sequences, we compared three algorithms for creating a single diagnostic quality image that combined input images containing flowing contrast agent. These image-stacking algorithms were: maximum opacity with the minimum gray-scale value across time recorded at each spatial location, (REC) recursive temporal filtering followed by a maximum opacity operation, and (AMF) an approximate matched filter consisting of a convolution with a kernel approximating the matched filter followed by a maximum opacity operation. Eighteen clinical exams of the peripheral arteries of the legs were evaluated. AMF gave 2.7 times greater contrast to noise ratio than the single best subtraction image and 1.3 times improvement over REC, the second best stacking algorithm. This is consistent with previous simulations showing that AMF performs nearly equal to the optimal result from matched filtering without the well-known limitations. For example, unlike matched filtering, AMF filter coefficients were obtained automatically using an image-processing algorithm. AMF effectively brought out small collateral arteries, otherwise difficult to see, without degrading artery sharpness or stenosis grading. Comparing results using reduced and full contrast agent volumes demonstrated that contrast agent load could be reduced to one-third of the conventional amount with AMF processing. By simulating reduced x-ray exposures on clinical exams, we determined that x-ray exposure could be reduced by 80% with AMF processing. We conclude that AMF is a promising, potential technique for reducing contrast agent load and for improving vessel visibility, both very important characteristics for vascular imaging.
13. Accuracy of Digital Subtraction Radiography in the Detection of Vertical Root Fractures.
Queiroz, Polyane Mazucatto; Nascimento, Helena Aguiar Ribeiro; da Paz, Thais Diniz Jacome; Anacleto, Felipe Nogueira; Freitas, Deborah Queiroz
2016-06-01
14. Two-dimensional thick-slice MR digital subtraction angiography for assessment of cerebrovascular occlusive diseases
Aoki, S.; Yoshikawa, T.; Hori, M.; Ishigame, K.; Nambu, A.; Kumagai, H.; Araki, T. [Dept. of Radiology, Yamanashi Medical Univ. (Japan)
2000-12-01
Although spatial resolution of current MR angiography is excellent, temporal resolution has remained unsatisfactory. We evaluated clinical applicability of 2D thick-slice, contrast-enhanced subtraction MR angiography (2D-MR digital subtraction angiography) with sub-second temporal resolution in cerebrovascular occlusive diseases. Twenty-five patients with cerebrovascular occlusive diseases (8 moyamoya diseases, 10 proximal internal carotid occlusions, and 2 sinus thromboses) were studied with a 1.5-T MR unit. The MR digital subtraction angiography (MRDSA) was performed per 0.97 s continuously just after a bolus injection of 15 ml of gadolinium chelates up to 40 s in sagittal (covering hemisphere) or coronal planes. Subtraction images were generated at a workstation. We evaluated imaging quality and hemodynamic information of MRDSA in comparison with those of routine MR imaging, non-contrast MR angiography, and X-ray intra-arterial DSA. Major cerebral arteries, all of the venous sinuses, and most tributaries were clearly visualized with 2D MRDSA. Also, pure arterial phases were obtained in all cases. The MRDSA technique demonstrated prolonged circulation in sinus thromboses, distal patent lumen of proximal occlusion, and some collateral circulation. Such hemodynamic information was comparable to that of intra-arterial DSA. Two-dimensional thick-slice MRDSA with high temporal resolution has a unique ability to demonstrate cerebral hemodynamics equivalent to that of intra-arterial DSA and may play an important role for evaluation of cerebrovascular occlusive diseases. (orig.)
15. Gadofosveset-enhanced MR angiography of carotid arteries: does steady-state imaging improve accuracy of first-pass imaging? Comparison with selective digital subtraction angiography.
Anzidei, Michele; Napoli, Alessandro; Marincola, Beatrice Cavallo; Nofroni, Italo; Geiger, Daniel; Zaccagna, Fulvio; Catalano, Carlo; Passariello, Roberto
2009-05-01
16. Strategies for Human Tumor Virus Discoveries: from Microscopic Observation to Digital Transcriptome Subtraction
Ezra David Mirvish
2016-05-01
Full Text Available Over 20% of human cancers worldwide are associated with infectious agents, including viruses, bacteria, and parasites. Various methods have been used to identify human tumor viruses, including electron microscopic observations of viral particles, immunologic screening, cDNA library screening, nucleic acid hybridization, consensus PCR, viral DNA array chip, and representational difference analysis (RDA. With the Human Genome Project, a large amount of genetic information from humans and other organisms has accumulated over the last decade. Utilizing the available genetic databases, Patrick S. Moore, Yuan Chang, and colleagues developed digital transcriptome subtraction (DTS, an in silico method to sequentially subtract human sequences from tissue or cellular transcriptome, and discovered Merkel cell polyomavirus (MCV from Merkel cell carcinoma (MCC. Here we review the background and methods underlying the human tumor virus discoveries and explain how DTS was developed and used for the discovery of MCV.
17. Accuracy of digital subtraction radiography in combination with a contrast media in assessment of proximal caries depth
2008-07-01
Full Text Available Background and aims. Radiography is used to diagnose the demineralization process and carious lesions; however, conventional radiography and direct digital images do not show these lesions when the amount of demineralization is less than 40%. Digital subtraction radiography has recently been used to improve the diagnostic quality of these lesions. The purpose of this study was to compare the caries depth estimated by digital subtraction radiography in combination with barium sulfate in diagnosing proximal dental caries with histopathologic evaluation. Materials and methods. In this study 30 molars and premolars (24 demineralized lesions with cavity, 8 without cavity were studied. Direct digital images were taken (kVp: 68, mA: 8; t: 0.12 for premolars and t: 0.16 for molars whereas the position of X-ray tube and CCD receptor and teeth was fixed. To prepare the second images 135 gr/L barium sulfate was used. The images obtained with the same exposure and geometry and then subtracted. The depth of the lesions in direct digital and subtracted images were assessed and compared with the depth measured in histopathologic assessments. Results. The mean depths (± SD of the lesions were 1.80 ± 0.77 mm in direct digital radiography, 2.32 ± 0.76 mm in subtracted images after barium sulfate treatment, and 2.51 ± 0.43 mm in histopathologic sections. The statistical difference between direct digital radiography and the other methods was significant (P < 0.05. However, the differences were not statistically significant between subtracted images and histopathologic sections. The average intra-class correlation coefficient was 0.7241 (CI: 95%. Conclusion. The present study has demonstrated that digital subtraction radiography images have the potential to measure the depth of proximal caries with no significant difference with histopathologic evaluation.
18. Digital Subtraction Phonocardiography (DSP applied to the detection and characterization of heart murmurs
2011-12-01
Full Text Available Abstract Background During the cardiac cycle, the heart normally produces repeatable physiological sounds. However, under pathologic conditions, such as with heart valve stenosis or a ventricular septal defect, blood flow turbulence leads to the production of additional sounds, called murmurs. Murmurs are random in nature, while the underlying heart sounds are not (being deterministic. Innovation We show that a new analytical technique, which we call Digital Subtraction Phonocardiography (DSP, can be used to separate the random murmur component of the phonocardiogram from the underlying deterministic heart sounds. Methods We digitally recorded the phonocardiogram from the anterior chest wall in 60 infants and adults using a high-speed USB interface and the program Gold Wave http://www.goldwave.com. The recordings included individuals with cardiac structural disease as well as recordings from normal individuals and from individuals with innocent heart murmurs. Digital Subtraction Analysis of the signal was performed using a custom computer program called Murmurgram. In essence, this program subtracts the recorded sound from two adjacent cardiac cycles to produce a difference signal, herein called a "murmurgram". Other software used included Spectrogram (Version 16, GoldWave (Version 5.55 as well as custom MATLAB code. Results Our preliminary data is presented as a series of eight cases. These cases show how advanced signal processing techniques can be used to separate heart sounds from murmurs. Note that these results are preliminary in that normal ranges for obtained test results have not yet been established. Conclusions Cardiac murmurs can be separated from underlying deterministic heart sounds using DSP. DSP has the potential to become a reliable and economical new diagnostic approach to screening for structural heart disease. However, DSP must be further evaluated in a large series of patients with well-characterized pathology to determine
19. Digital Subtraction Phonocardiography (DSP) applied to the detection and characterization of heart murmurs.
Akbari, Mohammad Ali; Hassani, Kamran; Doyle, John D; Navidbakhsh, Mahdi; Sangargir, Maryam; Bajelani, Kourosh; Ahmadi, Zahra Sadat
2011-12-20
During the cardiac cycle, the heart normally produces repeatable physiological sounds. However, under pathologic conditions, such as with heart valve stenosis or a ventricular septal defect, blood flow turbulence leads to the production of additional sounds, called murmurs. Murmurs are random in nature, while the underlying heart sounds are not (being deterministic). We show that a new analytical technique, which we call Digital Subtraction Phonocardiography (DSP), can be used to separate the random murmur component of the phonocardiogram from the underlying deterministic heart sounds. We digitally recorded the phonocardiogram from the anterior chest wall in 60 infants and adults using a high-speed USB interface and the program Gold Wave http://www.goldwave.com. The recordings included individuals with cardiac structural disease as well as recordings from normal individuals and from individuals with innocent heart murmurs. Digital Subtraction Analysis of the signal was performed using a custom computer program called Murmurgram. In essence, this program subtracts the recorded sound from two adjacent cardiac cycles to produce a difference signal, herein called a "murmurgram". Other software used included Spectrogram (Version 16), GoldWave (Version 5.55) as well as custom MATLAB code. Our preliminary data is presented as a series of eight cases. These cases show how advanced signal processing techniques can be used to separate heart sounds from murmurs. Note that these results are preliminary in that normal ranges for obtained test results have not yet been established. Cardiac murmurs can be separated from underlying deterministic heart sounds using DSP. DSP has the potential to become a reliable and economical new diagnostic approach to screening for structural heart disease. However, DSP must be further evaluated in a large series of patients with well-characterized pathology to determine its clinical potential.
20. The potential for neurovascular intravenous angiography using K-edge digital subtraction angiography
Schültke, E.; Fiedler, S.; Kelly, M.; Griebel, R.; Juurlink, B.; LeDuc, G.; Estève, F.; Le Bas, J.-F.; Renier, M.; Nemoz, C.; Meguro, K.
2005-08-01
Background: Catheterization of small-caliber blood vessels in the central nervous system can be extremely challenging. Alternatively, intravenous (i.v.) administration of contrast agent is minimally invasive and therefore carries a much lower risk for the patient. With conventional X-ray equipment, volumes of contrast agent that could be safely administered to the patient do not allow acquisition of high-quality images after i.v. injection, because the contrast bolus is extremely diluted by passage through the heart. However, synchrotron-based digital K-edge subtraction angiography does allow acquisition of high-quality images after i.v. administration of relatively small doses of contrast agent. Materials and methods: Eight adult male New Zealand rabbits were used for our experiments. Animals were submitted to both angiography with conventional X-ray equipment and synchrotron-based digital subtraction angiography. Results: With conventional X-ray equipment, no contrast was seen in either cerebral or spinal blood vessels after i.v. injection of iodinated contrast agent. However, using K-edge digital subtraction angiography, as little as 1 ml iodinated contrast agent, when administered as i.v. bolus, yielded images of small-caliber blood vessels in the central nervous system (both brain and spinal cord). Conclusions: If it would be possible to image blood vessels of the same diameter in the central nervous system of human patients, the synchrotron-based technique could yield high-quality images at a significantly lower risk for the patient than conventional X-ray imaging. Images could be acquired where catheterization of feeding blood vessels has proven impossible.
1. Equilibrium radionuclide ventriculography: Comparison with echo-ventriculography and digital subtraction angiocardiography, evaluation of multiparameters
Hoer, G.; Standke, R.; Klepzig, H. Jr.; Maul, F.D.; Tuengerthal, S.; Tezak, S.; Reifarth, N.; Kanemoto, N.; Happ, J.; Baum, R.P.
1986-09-01
Subsequent to the discussion of technical prerequisites (fully-automated, reproducible multiparameter-analysis (MPA), rest, exercise) which is followed by remarks concerning the pathophysiology of ischemic left ventricular functional disorders in diastole and systole, the following points are considered: 1) comparative results of RNV, cineventriculoangiography, echo-ventriculography and intraveneous digital subtraction angiocardiography; 2) 'normal' values of RNV in MPA; 3) heart and pulmonary diseases (coronary artery disease with sensitivity and specificity of MPA), chronic obstructive pulmonary disease, chronic aortic insufficiency, hypertension; 4) summary of, and prospects for future potentialities (software, clinical indications).
2. Intravenous digital subtraction angiography in patients with coarctation of the aorta (stenosis of the aortic isthmus)
Rauber, K.; Kollath, J.
1985-02-01
The authors report on 18 patients with stenoses of the aortic isthmus in whom digital subtraction angiography had been carried out. In three patients DSA yielded the primary diagnosis of a postductal stenosis of the aortic isthmus. In all postoperative patients, restenosis of the aorta could either be excluded or confirmed. In three cases with complications after an operation, DSA supplied diagnostic information which was decisive for proceeding further. According to the authors' experience, intravenous DSA can replace conventional angiography in the majority of postoperative controls and in future also in primary diagnosis.
3. Role of digital tomosynthesis and dual energy subtraction digital radiography in detection of parenchymal lesions in active pulmonary tuberculosis
Sharma, Madhurima, E-mail: [email protected] [Department of Radiodiagnosis and Imaging, PGIMER, Chandigarh 160012 (India); Sandhu, Manavjit Singh, E-mail: [email protected] [Department of Radiodiagnosis and Imaging, PGIMER, Chandigarh 160012 (India); Gorsi, Ujjwal, E-mail: [email protected] [Department of Radiodiagnosis and Imaging, PGIMER, Chandigarh 160012 (India); Gupta, Dheeraj, E-mail: [email protected] [Department of Pulmonary Medicine, PGIMER, Chandigarh 160012 (India); Khandelwal, Niranjan, E-mail: [email protected] [Department of Radiodiagnosis and Imaging, PGIMER, Chandigarh 160012 (India)
2015-09-15
Highlights: • Digital tomosynthesis and dual energy subtraction digital radiography are modifications of digital radiography. • These modalities perform better than digital radiography in detection of parenchymal lesions in active pulmonary tuberculosis. • Digital tomosynthesis has a sensitivity of 100% in detection of cavities. • Centrilobular nodules seen on CT in active pulmonary tuberculosis, were also demonstrated on digital tomosynthesis in our study. • Digital tomosynthesis can be used for diagnosis and follow up of patients in pulmonary tuberculosis, thereby reducing the number of CT examinations. - Abstract: Objective: To assess the role of digital tomosynthesis (DTS) and dual energy subtraction digital radiography (DES-DR) in detection of parenchymal lesions in active pulmonary tuberculosis (TB) and to compare them with digital radiography (DR). Materials and methods: This prospective study was approved by our institutional review committee. DTS and DES-DR were performed in 62 patients with active pulmonary TB within one week of multidetector computed tomography (MDCT) study. Findings of active pulmonary TB, that is consolidation, cavitation and nodules were noted on digital radiography (DR), DTS and DES-DR in all patients. Sensitivity, specificity, positive and negative predictive values of all 3 modalities was calculated with MDCT as reference standard. In addition presence of centrilobular nodules was also noted on DTS. Results: Our study comprised of 62 patients (33 males, 29 females with age range 18–82 years). Sensitivity and specificity of DTS for detection of nodules and cavitation was better than DR and DES-DR. Sensitivity and specificity of DTS for detection of consolidation was comparable to DR and DES-DR. DES-DR performed better than DR in detection of nodules and cavitation. DTS was also able to detect centrilobular nodules with sensitivity and specificity of 57.4% and 86.5% respectively. Conclusion: DTS and DES-DR perform better
4. Accuracy of digital subtraction radiography in combination with a contrast media in assessment of proximal caries depth.
2008-01-01
Radiography is used to diagnose the demineralization process and carious lesions; however, conventional radiography and direct digital images do not show these lesions when the amount of demineralization is less than 40%. Digital subtraction radiography has recently been used to improve the diagnostic quality of these le-sions. The purpose of this study was to compare the caries depth estimated by digital subtraction radiog-raphy in combination with barium sulfate in diag-nosing proximal dental caries with histopathologic evaluation. In this study 30 molars and premolars (24 demineralized lesions with cavity, 8 without cavity) were studied. Direct digital images were taken (kVp: 68, mA: 8; t: 0.12 for premolars and t: 0.16 for molars) whereas the position of X-ray tube and CCD receptor and teeth was fixed. To prepare the second images 135 gr/L barium sulfate was used. The images obtained with the same exposure and geometry and then subtracted. The depth of the lesions in direct digital and subtracted images were assessed and compared with the depth measured in histopathologic assessments. The mean depths (± SD) of the lesions were 1.80 ± 0.77 mm in direct digital radiography, 2.32 ± 0.76 mm in subtracted images after barium sulfate treatment, and 2.51 ± 0.43 mm in histopathologic sections. The statistical difference between direct digital radiography and the other methods was significant (P digital subtraction radiography images have the potential to measure the depth of proximal caries with no significant difference with histopathologic evaluation.
5. Assessment of vasospasm in experimental subarachnoid hemorrhage in rats by selective biplane digital subtraction angiography
Weidauer, Stefan; Dettmann, Edgar; Zanella, Friedhelm E. [University of Frankfurt, Institute of Neuroradiology, Frankfurt (Germany); Vatter, Hartmut; Seifert, Volker [University of Frankfurt, Clinic of Neurosurgery, Frankfurt (Germany)
2006-03-15
Although the rat subarachnoid hemorrhage model is well established in vasospasm research, the angiographic evaluation is difficult due to the animal's small size. For this reason, the aim of the study was to develop a standardized angiographic examination technique without additional complex equipment. Under general anesthesia, 11 Sprague-Dawley rats underwent selective cerebral digital subtraction angiography using a 0.3 mm focal spot and a 2.0-fold linear magnification. Five animals had experimental subarachnoid hemorrhage according to the ''double-hemorrhage'' model. Comparison with the intraarterial tip of the microcatheter enabled calibration of the vessel lumen. The diameter of the normal basilar artery (n=6) was 0.34{+-}0.03 mm (mean{+-}SD), whereas delayed vasospastic constriction (mean 6.2 days) caused a reduction in diameter of 32.4% (0.23{+-}0.09 mm) as well as impaired collateral blood flow via the posterior communicating artery and anterior spinal artery. Histological examination of sections stained with hematoxylin and eosin under a light microscope confirmed vasospasm. In conclusion, biplane digital subtraction angiography allows precise and reliable evaluation of arterial diameter reduction and hemodynamic parameters in a rat vasospasm model. However, further investigation is required for assessment of vasoactive drugs, e.g., endothelin receptor antagonists. (orig.)
6. Comparison of the diagnostic accuracy of direct digital radiography system, filtered images, and subtraction radiography
Wilton Mitsunari Takeshita
2013-01-01
Full Text Available Background: To compare the diagnostic accuracy of three different imaging systems: Direct digital radiography system (DDR-CMOS, four types of filtered images, and a priori and a posteriori registration of digital subtraction radiography (DSR in the diagnosis of proximal defects. Materials and Methods: The teeth were arranged in pairs in 10 blocks of vinyl polysiloxane, and proximal defects were performed with drills of 0.25, 0.5, and 1 mm diameter. Kodak RVG 6100 sensor was used to capture the images. A posteriori DSR registrations were done with Regeemy 0.2.43 and subtraction with Image Tool 3.0. Filtered images were obtained with Kodak Dental Imaging 6.1 software. Images (n = 360 were evaluated by three raters, all experts in dental radiology. Results: Sensitivity and specificity of the area under the receiver operator characteristic (ROC curve (Az were higher for DSR images with all three drills (Az = 0.896, 0.979, and 1.000 for drills 0.25, 0.5, and 1 mm, respectively. The highest values were found for 1-mm drills and the lowest for 0.25-mm drills, with negative filter having the lowest values of all (Az = 0.631. Conclusion: The best method of diagnosis was by using a DSR. The negative filter obtained the worst results. Larger drills showed the highest sensitivity and specificity values of the area under the ROC curve.
7. The Reduction Of Motion Artifacts In Digital Subtraction Angiography By Geometrical Image Transformation
Fitzpatrick, J. Michael; Pickens, David R.; Mandava, Venkateswara R.; Grefenstette, John J.
1988-06-01
In the diagnosis of arteriosclerosis, radio-opaque dye is injected into the interior of the arteries to make them visible. Because of its increased contrast sensitivity, digital subtraction angiography has the potential for providing diagnostic images of arteries with reduced dye volumes. In the conventional technique, a mask image, acquired before the introduction of the dye, is subtracted from the contrast image, acquired after the dye is introduced, to produce a difference image in which only the dye in the arteries is visible. The usefulness of this technique has been severely limited by the image degradation caused by patient motion during image acquisition. This motion produces artifacts in the difference image that obscure the arteries. One technique for dealing with this problem is to reduce the degradation by means of image registration. The registration is carried out by means of a geometrical transformation of the mask image before subtraction so that it is in registration with the contrast image. This paper describes our technique for determining an optimal transformation. We employ a one-to-one elastic mapping and the Jacobian of that mapping to produce a geometrical image transformation. We choose a parameterized class of such mappings and use a heuristic search algorithm to optimize the parameters to minimize the severity of the motion artifacts. To increase the speed of the optimization process we use a statistical image comparison technique that provides a quick approximate evaluation of each image transformation. We present the experimental results of the application of our registration system to mask-contrast pairs, for images acquired from a specially designed phantom (described in a companion paper), and for clinical images.
8. Novel method for digital subtraction of tagged stool in virtual colonoscopy
Guendel, Lutz; Suehling, Michael; Eckert, Helmut
2008-03-01
Colon cancer is one of the most frequent causes of death. CT colonography is a novel method for the detection of polyps and early cancer. The general principle of CT colonography includes a cathartic bowel preparation. The resulting discomfort for patients leads to limited patient acceptance and therefore to limited cancer detection rates. Reduced bowel preparation, techniques for stool tagging, and electronic cleansing, however, improve the acceptance rates. Hereby, the high density of oral contrast material highlights residual stool and can be digitally removed. Known subtraction methods cause artifacts: additional 3D objects are introduced and small bowel folds are perforated. We propose a new algorithm that is based on the 2 nd derivative of the image data using the Hessian matrix and the following principal axis transform to detect tiny folds which shall not be subtracted together with tagged stool found by a thresholding method. Since the stool is usually not homogenously tagged with contrast media a detection algorithm for island-like structures is incorporated. The interfaces of air-stool level and colon wall are detected by a 3-dimensional difference of Gaussian module. A 3-dimensional filter smoothes the transitions between removed stool and colon tissue. We evaluated the efficacy of the new algorithm with 10 patient data sets. The results showed no introduced artificial objects and no perforated folds. The artifacts at the air-stool and colon tissue-stool transitions are considerably reduced compared to those known from the literature.
9. Quantitative digital subtraction radiography for assessment of bone density changes following periodontal guided tissue regeneration.
Christgau, M; Wenzel, A; Hiller, K A; Schmalz, G
1996-01-01
The quantitative assessment of alveolar bone density changes in periodontal defects following guided tissue regeneration (GTR). Twelve patients with 30 intrabony lesions and 16 furcation defects took part. Standardized radiographic and clinical examinations were carried out immediately before and then 5 and 13 months after surgery. Intra-oral radiographs were evaluated by means of digital subtraction radiography (DSR). Within the subtraction images, a window ('experimental region') was defined covering the visible density changes in the defect area. Background noise was measured by using a similarly sized window ('control region') located in an area not affected by GTR. Bone density changes were quantitatively evaluated by calculation of the mean, standard deviation and maximum and minimum values of the grey-level histogram within these windows. DSR revealed significant bone density gain after GTR in intrabony and furcation defects. While a continuous increase was observed over the 13 month period in intrabony defects, changes in furcation defects occurred mostly in the 5-13 month period. Clinically, a distinct vertical and horizontal attachment gain was found. The correlation coefficients between changes in radiographic density and clinical parameters were low, indicating a difference in the information obtained by the two diagnostic methods. Quantitative DSR is a valuable, non-invasive, objective method to obtain information on density changes in intrabony and furcation defects treated by GTR. However, a full assessment of soft and hard tissue changes requires both clinical evaluation and DSR.
10. Three-dimensional digital subtraction angiography vs two-dimensional digital subtraction angiography for detection of ruptured intracranial aneurysms: A study of 86 aneurysms
Kawashima Masatou
2005-01-01
Full Text Available Aims : Three-dimensional reconstruction of intracranial vessels is of interest for evaluation of aneurysms. This study determined diagnostic difference of three-dimensional digital subtraction angiography (3D-DSA, volume-rendering image versus 2D-DSA for evaluating ruptured intracranial aneurysms, particularly focusing on the size of aneurysms as depicted in both images. Settings and Design : Sixty-nine patients underwent 3D-DSA and 2D-DSA. The relative size of an aneurysm, which is the ratio of the maximal diameter of an aneurysm to the diameter of a major vessel, was compared between imaging techniques. In addition, relative sizes of smaller aneurysms (10 mm. Statistical analysis used : For comparison of aneurysm size and location of aneurysm, statistical analysis was performed with the Yates chi square test; statistical significance was set with a P value of less than 0.05. Results: Sixty-three (73.3% of the 86 total aneurysms were bigger when measured with 3D-DSA versus 2D-DSA. When measured with 3D-DSA, 28 (84.8% of the 33 smaller aneurysms were bigger, and 50% of the larger aneurysms were bigger versus measurements of 2D-DSA images ( P P Conclusions : 3D-DSA, especially volume-rendering images, tends to depict ruptured intracranial aneurysms bigger than 2D-DSA. This is particularly true with cerebral aneurysms that are <5 mm in size and are located in the anterior circulation, especially ICA and ACA territories.
11. [Affine transformation-based automatic registration for peripheral digital subtraction angiography (DSA)].
Kong, Gang; Dai, Dao-Qing; Zou, Lu-Min
2008-07-01
In order to remove the artifacts of peripheral digital subtraction angiography (DSA), an affine transformation-based automatic image registration algorithm is introduced here. The whole process is described as follows: First, rectangle feature templates are constructed with their centers of the extracted Harris corners in the mask, and motion vectors of the central feature points are estimated using template matching technology with the similarity measure of maximum histogram energy. And then the optimal parameters of the affine transformation are calculated with the matrix singular value decomposition (SVD) method. Finally, bilinear intensity interpolation is taken to the mask according to the specific affine transformation. More than 30 peripheral DSA registrations are performed with the presented algorithm, and as the result, moving artifacts of the images are removed with sub-pixel precision, and the time consumption is less enough to satisfy the clinical requirements. Experimental results show the efficiency and robustness of the algorithm.
12. Idiopathic Thrombus in the Common Carotid Artery on Digital Subtraction Angiography
Anand Alurkar
2012-01-01
Full Text Available In the present study, we discuss the accuracy of digital subtraction angiography (DSA in diagnosis of thrombus in the common carotid artery and its role in the medical management of this disorder. Between 2006 and 2011, four patients (age group ranging from 26 to 48 years presented to our institution with symptoms of stroke. DSA in all these patients showed cigar-shaped filling defect in the common carotid artery. All the patients were managed successfully with anticoagulation treatment. Follow-up Duplex scan was done in all the patients. DSA is the gold standard to diagnose free floating thrombus in the common carotid artery. Medical management can be effective in these patients but a multidisciplinary team approach is needed for appropriate management.
13. K-edge digital subtraction imaging based on a dichromatic and compact x-ray source
Sarnelli, A.; Taibi, A.; Tuffanelli, A.; Baldazzi, G.; Bollini, D.; Cabal Rodriguez, A. E.; Gombia, M.; Prino, F.; Ramello, L.; Tomassi, E.; Gambaccini, M.
2004-07-01
This work proposes a compact dichromatic imaging system for the application of the K-edge digital subtraction technique based on a conventional x-ray tube and a monochromator system. A quasi-monochromatic x-ray beam at the energy of iodine K-edge is produced by Bragg diffraction on a mosaic crystal. Two thin adjacent beams with energies that bracket the K-edge discontinuity are obtained from the diffracted beam by means of a proper collimation system. They are then detected using an array of Si detectors. A home-made phantom is used to study the image quality as a function of iodine concentration. Signal and signal-to-noise ratio analysis has also been performed. The results are compared with theoretical expectations.
14. The use of neurovascular ultrasound versus digital subtraction angiography in acute ischemic stroke
Marcos C. Lange
2015-03-01
Full Text Available Cervical and intracranial arterial evaluation is an important issue for acute ischemic stroke (IS. Objective Compare the use of the neurovascular ultrasound examination (NVUE to digital subtraction angiography (DSA in acute IS patients for diagnosing significant extracranial and intracranial arteriopathy. Method Nonconsecutive patients with IS or transient ischemic attack admitted within 12 hours of the onset of symptoms were evaluated retrospectively. Standardized NVUE and DSA were done in all patients within the first 120 hours of hospital admission. Results Twenty-four patients were included in the study. Compared to DSA, the NVUE demonstrated 94.7% sensitivity and 100% specificity for identifying symptomatic extracranial and/or intracranial arteriopathy. Conclusion The standardized NVUE technique demonstrated high sensitivity and specificity compared to DSA for diagnosing arterial abnormalities in acute IS patients.
15. K-edge digital subtraction imaging based on a dichromatic and compact x-ray source
Sarnelli, A [Dipartimento di Fisica dell' Universita di Ferrara and INFN Sezione di Ferrara, Via Paradiso 12, I-44100 Ferrara (Italy); Taibi, A [Dipartimento di Fisica dell' Universita di Ferrara and INFN Sezione di Ferrara, Via Paradiso 12, I-44100 Ferrara (Italy); Tuffanelli, A [Dipartimento di Fisica dell' Universita di Ferrara and INFN Sezione di Ferrara, Via Paradiso 12, I-44100 Ferrara (Italy); Baldazzi, G [Dipartimento di Fisica dell' Universita di Bologna and INFN Sezione di Bologna, Viale Berti Pichat 64/2, 40127 Bologna (Italy); Bollini, D [Dipartimento di Fisica dell' Universita di Bologna and INFN Sezione di Bologna, Viale Berti Pichat 64/2, 40127 Bologna (Italy); Rodriguez, A E Cabal [CAEDAN, Havana (Cuba); Gombia, M [Dipartimento di Fisica dell' Universita di Bologna and INFN Sezione di Bologna, Viale Berti Pichat 64/2, 40127 Bologna (Italy); Prino, F [Dipartimento di Scienze e Tecnologie Avanzate, Universita del Piemonte Orientale and INFN Sezione di Alessandria, C.so, Borsalino 54, I-15100 Alessandria (Italy); Ramello, L [Dipartimento di Scienze e Tecnologie Avanzate, Universita del Piemonte Orientale and INFN Sezione di Alessandria, C.so, Borsalino 54, I-15100 Alessandria (Italy); Tomassi, E [Dipartimento di Scienze e Tecnologie Avanzate, Universita del Piemonte Orientale and INFN Sezione di Alessandria, C.so, Borsalino 54, I-15100 Alessandria (Italy); Gambaccini, M [Dipartimento di Fisica dell' Universita di Ferrara and INFN Sezione di Ferrara, Via Paradiso 12, I-44100 Ferrara (Italy)
2004-07-21
This work proposes a compact dichromatic imaging system for the application of the K-edge digital subtraction technique based on a conventional x-ray tube and a monochromator system. A quasi-monochromatic x-ray beam at the energy of iodine K-edge is produced by Bragg diffraction on a mosaic crystal. Two thin adjacent beams with energies that bracket the K-edge discontinuity are obtained from the diffracted beam by means of a proper collimation system. They are then detected using an array of Si detectors. A home-made phantom is used to study the image quality as a function of iodine concentration. Signal and signal-to-noise ratio analysis has also been performed. The results are compared with theoretical expectations.
16. Effectiveness of digital subtraction radiography in detecting artificially created osteophytes and erosions in the temporomandibular joint
Kocasarac, Husniye Demirturk [Dept. of Comprehensive Dentistry, The University of Texas Health Science Center, San Antonio (United States); Celenk, Peruze [Dept. of Oral and Maxillofacial Radiology, Faculty of Dentistry, Ondokuz Mayis University, Samsun (Turkmenistan)
2017-06-15
Erosions and osteophytes are radiographic characteristics that are found in different stages of temporomandibular joint (TMJ) osteoarthritis. This study assessed the effectiveness of digital subtraction radiography (DSR) in diagnosing simulated osteophytes and erosions in the TMJ. Five intact, dry human skulls were used to assess the effectiveness of DSR in detecting osteophytes. Four cortical bone chips of varying thicknesses (0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm) were placed at the medial, central, and lateral aspects of the condyle anterior surface. Two defects of varying depth (1.0 mm and 1.5 mm) were created on the lateral, central, and medial poles of the condyles of 2 skulls to simulate erosions. Panoramic images of the condyles were acquired before and after artificially creating the changes. Digital subtraction was performed with Emago dental image archiving software. Five observers familiar with the interpretation of TMJ radiographs evaluated the images. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic accuracy of the imaging methods. The area under the ROC curve (Az) value for the overall diagnostic accuracy of DSR in detecting osteophytic changes was 0.931. The Az value for the overall diagnostic accuracy of panoramic imaging was 0.695. The accuracy of DSR in detecting erosive changes was 0.854 and 0.696 for panoramic imaging. DSR was remarkably more accurate than panoramic imaging in detecting simulated osteophytic and erosive changes. The accuracy of panoramic imaging in detecting degenerative changes was significantly lower than the accuracy of DSR (P<.05). DSR improved the accuracy of detection using panoramic images.
17. Pilot study: digital subtraction radiography as a tool to assess alveolar bone changes in periodontitis patients under treatment with subantimicrobial doses of doxycycline
A.D. Goren; S.M. Dunn; M. Wolff; P.F. van der Stelt; D.C. Colosi; L.M. Golub
2008-01-01
Background Subtle changes in marginal alveolar bone level can be demonstrated using digital subtraction of sequential radiographs. Objective We aimed to evaluate the practical application of geometrically corrected digital subtraction in a clinical study of alveolar bone response to a drug previousl
18. Evaluation of chronic periapical lesions by digital subtraction radiography by using Adobe Photoshop CS: a technical report.
Carvalho, Fabiola B; Gonçalves, Marcelo; Tanomaru-Filho, Mário
2007-04-01
The purpose of this study was to describe a new technique by using Adobe Photoshop CS (San Jose, CA) image-analysis software to evaluate the radiographic changes of chronic periapical lesions after root canal treatment by digital subtraction radiography. Thirteen upper anterior human teeth with pulp necrosis and radiographic image of chronic periapical lesion were endodontically treated and radiographed 0, 2, 4, and 6 months after root canal treatment by using a film holder. The radiographic films were automatically developed and digitized. The radiographic images taken 0, 2, 4, and 6 months after root canal therapy were submitted to digital subtraction in pairs (0 and 2 months, 2 and 4 months, and 4 and 6 months) choosing "image," "calculation," "subtract," and "new document" tools from Adobe Photoshop CS image-analysis software toolbar. The resulting images showed areas of periapical healing in all cases. According to this methodology, the healing or expansion of periapical lesions can be evaluated by means of digital subtraction radiography by using Adobe Photoshop CS software.
19. A digital subtraction radiography based tool for periodontal bone resorption analysis
Schiabel, Homero; Rodrigues, Eveline B., E-mail: [email protected] [University of Sao Paulo (EESC/USP), Sao Carlos, SP (Brazil). Dept. of Electrical Engineering; Rubira-Bullen, Izabel R.F. [University of Sao Paulo (USP), Bauru, SP (Brazil). Bauru Dentistry School
2011-07-01
The aim of this paper was to describe an aided diagnosis scheme for periodontal bone resorption so that the dentist can make an early diagnosis of the periodontal disease and establish the best treatment plan to increase the success of healing. Three ways of displaying the results are provided: qualitative, simple quantitative and colored-percentage quantitative views. A total of 72 pairs of in vitro radiographic images were used. The main procedure registers the images perspective projection aimed to align them in rotation and translation, and is followed by the application of a contrast correction technique. The results from the subtraction were evaluated firstly by the comparison between the actual and the digital sizes corresponding to the holes made by drills in phantoms. The mean error was 4.2%. The method was also applied to actual tooth radiographic images and could detect clearly the effect of treatment of periodontal diseases. It is dependent on the reproducibility of the process of radiographs acquisition and digitization, but the calculated mean error allows to conclude its better efficacy compared to usual procedures in this field. (author)
20. Clinical relevance of negative initial angiogram in spontaneous subarachnoid hemorrhage.
Moscovici, Samuel; Fraifeld, Shifra; Ramirez-de-Noriega, Fernando; Rosenthal, Guy; Leker, Ronen R; Itshayek, Eyal; Cohen, José E
2013-03-01
We aimed to compare the presentation, management, and clinical course in patients with perimesencephalic and nonperimesencephalic (aneurysmal) bleeding patterns on noncontrast CT, but negative initial 4-vessel digital subtraction angiography (DSA). We retrospectively reviewed clinical and imaging data for 280 patients presenting with spontaneous SAH admitted between 2005 and 2011. We identified 56 patients (20%) with SAH diagnosed on high resolution head CT performed within 48 hours of admission, and negative initial DSA, and divided them into perimesencephalic and non-perimesencephalic groups based on hemorrhage patterns. Patients with traumatic subarachnoid bleeding and those with initial positive DSA were excluded from this analysis. Perimesencephalic SAH was seen in 25 patients (45%); non-perimesencephalic bleeding patterns were seen in 31 (55%). All patients with perimesencephalic SAH presented with Hunt and Hess (HH) I, versus 45% HH I and 55% HH II-IV in those with non-perimecenphalic SAH. All patients with perimesencephalic SAH achieved modified Rankin score (mRS) 0 at discharge and 6-month follow-up, compared with 45% mRS 0 at discharge and 68% at 6-month follow-up in non-perimesencephalic SAH. Patients with perimesencephalic SAH presented a uniformly uncomplicated clinical course. Among non-perimesencephalic SAH patients there were 19 neurological/neurosurgical and 10 medical complications, two small aneurysms diagnosed at follow-up DSA, and one death. In this series, perimesencephalic SAH was associated with good clinical grades, consistently negative initial and follow-up angiograms, and an excellent prognosis. In contrast, non-perimesencephalic SAH was associated with a worse clinical presentation, higher complication rates, higher rates of true aneurysm detection on follow-up angiogram, and a poorer outcome.
1. Intravenous digital subtraction angiography in the assessment of patients with left to right shunts before and after surgical correction
Yiannikas, J.; Moodie, D.S.; Gill, C.C.; Sterba, R.; McIntyre, R.; Buonocore, E.
1984-06-01
Pre- and postoperative structural changes and pulmonary to systemic flow (QP/QS) ratios were assessed using digital angiography in 34 patients documented to have a left to right shunt at cardiac catheterization. There were 16 men and 18 women whose ages ranged from 4 months to 60 years. The radiographic single mask mode was used for all digital subtraction angiographic studies with a typical radiographic sequence being 80 to 100 kV, 5 to 10 mA/frame at six frames/s for 15 seconds. Renografin-76 was used as a bolus injection at 0.5 to 1.0 ml/kg via an arm vein in most patients. The level of the left to right shunt and any associated anomalies were noted and compared with results from cardiac catheterization. Digital subtraction angiographic flow curves were generated from the pulmonary arteries, and QP/QS ratios were calculated pre- and postoperatively using the gamma variate fit method and compared with the QP/QS ratio from first pass radionuclide studies. A strong correlation between preoperative digital subtraction angiographically derived QP/QS ratio and radionuclide-derived QP/QS ratio was found, with an r value equal to 0.89, p less than 0.0001. Postoperatively, all patients had a QP/QS ratio less than 1.2:1.0 for both digital subtraction angiography and radionuclide studies. The level of left to right shunt was accurately assessed in all patients, and its absence observed postoperatively. Associated anomalies, such as a persistent left superior vena cava, coarctation of the aorta and partial anomalous venous return, were identified in all cases.
2. K-edge digital subtraction imaging with dichromatic x-ray sources: SNR and dose studies
Sarnelli, A.; Elleaume, H.; Taibi, A.; Gambaccini, M.; Bravin, A.
2006-09-01
The aim of the present work is to analytically evaluate the signal to noise ratio (SNR) and the delivered dose in K-edge digital subtraction imaging (KES) using two types of x-ray sources: a monochromatic x-ray source (available at synchrotron radiation facilities and considered as gold standard) and a quasi-monochromatic compact source. The energy separation ΔE between the two monochromatic beams is 1 keV and 4 keV for the two sources, respectively. The evaluation has been performed for both radiography and computed tomography. Different geometries have been studied to mimic clinical situations. In mammography, a pathology perfused by a contrast agent has been modelled; in angiography, a vessel superimposed to a ventricle or a stand-alone artery stenosis has been studied. The SNR and the skin dose have been calculated as a function of the detail diameter, the contrast agent (iodine and gadolinium), and its concentration in the tissues. Results show that for ΔE = 4 keV a slightly higher delivered dose is required to obtain the same SNR with respect to ΔE < 1 keV. A similar study has been performed for KES-CT. Computer simulations of CT images performed with Snark software are shown to validate the analytical calculations.
3. Predictive value of digital subtraction angiography in patients with tuberculous meningitis
Rojas-Echeverri, L.A. [Dept. of Neuroimaging and Endovascular Therapy, National Inst. for Neurology and Neurosurgery, Mexico City (Mexico); Soto-Hernandez, J.L. [Infectious Disease Dept., National Inst. for Neurology and Neurosurgery, Tlalpan (Mexico); Garza, S. [Div. of Neurology, National Inst. for Neurology and Neurosurgery, Tlalpan (Mexico); Martinez-Zubieta, R. [Div. of Neurology, National Inst. for Neurology and Neurosurgery, Tlalpan (Mexico); Miranda, L.I. [Div. of Neurology, National Inst. for Neurology and Neurosurgery, Tlalpan (Mexico); Garcia-Ramos, G. [Div. of Neurology, National Inst. for Neurology and Neurosurgery, Tlalpan (Mexico); Zenteno, M. [Dept. of Neuroimaging and Endovascular Therapy, National Inst. for Neurology and Neurosurgery, Mexico City (Mexico)
1996-01-01
Digital subtraction angiography (DSA) was performed in 24 adults with tuberculous meningitis (TBM) and results were correlated with 24 admission and 16 follow-up CT examinations. 19 MRI studies and clinical outcome at a mean follow-up of 44 weeks. DSA was abnormal in 11 patients. Abnormal DSA was associated with advenced clinical stages of the Medical Research Council classification, admission CT with hydrocephalus or gyral cortical enhancement. MRI disclosed brain infarcts not seen on initial CT in 8 cases. Of seven patients who died, 4 had abnormal and 3 normal DSA. Among patients who survived, those with normal DSA had a better functional outcome by Karnofsky scores. During follow-up infarcts were evident in 16 patients. Abnormal DSA in relation to brain infarcts had a sensitivity of 0.56, specificity 0.75, positive predictive value 0.82 and negative predictive value 0.46. A single arteriogram does not predict the outcome in patients with TBM and its value is limited in the assessment of vascular complications of TBM. Angiography in TBM is justified only in specific clinical trials to assess new therapeutic modalities against infarcts. (orig.)
4. Blood flow measurement using digital subtraction angiography for assessing hemodialysis access function
Koirala, Nischal; Setser, Randolph M.; Bullen, Jennifer; McLennan, Gordon
2017-03-01
Blood flow rate is a critical parameter for diagnosing dialysis access function during fistulography where a flow rate of 600 ml/min in arteriovenous graft or 400-500 ml/min in arteriovenous fistula is considered the clinical threshold for fully functioning access. In this study, a flow rate computational model for calculating intra-access flow to evaluate dialysis access patency was developed and validated in an in vitro set up using digital subtraction angiography. Flow rates were computed by tracking the bolus through two regions of interest using cross correlation (XCOR) and mean arrival time (MAT) algorithms, and correlated versus an in-line transonic flow meter measurement. The mean difference (mean +/- standard deviation) between XCOR and in-line flow measurements for in vitro setup at 3, 6, 7.5 and 10 frames/s was 118+/-63 37+/-59 31+/-31 and 46+/-57 ml/min respectively while for MAT method it was 86+/-56 57+/-72 35+/-85 and 19+/-129 ml/min respectively. The result of this investigation will be helpful for selecting candidate algorithms while blood flow computational tool is developed for clinical application.
5. Digital subtraction angiography in the diagnosis of invasive hydatidiform mole. Comparison with PAG, CT and USG
Ikuma, Kenichiro; Daimon, Michiko; Muranaka, Junko; Suno, Shigeo; Takayasu, Yukio; Shibahara, Hiroaki; Sawai, Hideaki
1987-11-01
Pelvic angiography (PAG) by Seldinger is one of the most useful examinations for the diagnosis of trophoblastic disease and also for the assessment of the therapeutic results. This technique, however, causes some stress to the patient. Therefore, noninvasive method, such as computed tomography (CT) and ultrasonography (USG) have recently been introduced. In the 1980s, digital subtraction angiography (DSA) was developed. It is now being used increasingly in the fields of Obstetrics and Gynecology as a substitute for the conventional PAG. In this report, the results of DSA, PAG, CT and USG which were carried out before and after chemotherapy in a patient with invasive hydatidiform mole were compared. In terms of the location, size and shape of the lesion, the CT findings were almost the same as those of USG. In terms of the angiographic findings in the affected area, intravenous DSA (IVDSA) was a sufficiently substitutional examination for conventional PAG. With IVDSA, arterial images can be obtained following the intravenous injection of a contrast medium. Therefore, this technique is excellent in terms of simplicity and safety. From now on, DSA will be utilized instead of PAG as an effective diagnostic method for trophoblastic disease and for follow-up such cases.
6. Experience with intravenous digital subtraction angiography following shunting in 4 cases of congenital heart diseases
Higashidate, Masafumi; Konno, Susumu; Sumitomo, Naokata; Ito, Sango; Kobayashi, Hiroshi
1985-01-01
Intravenous digital subtraction angiography (IV-DSA) was performed in two patients with Fallot's tetralogy who underwent Blalock-Taussing operation, a patient with coarctation of the aortic arch who underwent extra-anastomic bypass between the ascending aorta and the descending aorta, and a patient with stenosis of the tricuspid valve who underwent Fontan type operation (anastomosis between the right atrium and the pulmonary artery). The conventional cardiac angiography was also performed for the comparison with IV-DSA in all patients. IV-DSA revealed the thickness of the subclavian artery anastomosed by Blaloch-Taussing operation, but failed to determine the accurate thickness of the pulmonary artery required for PA-index for radical surgery in cases of Fallot's tetralogy. Bypass from the ascending aorta to the descending aorta was well visualized by IV-DSA because the heart did not overlap on the image. In cases of Fontan type operation, IV-DSA permitted the visualization of blood flow from the right atrium to the pulmonary artery and the shape of the pulmonary artery. It is concluded that IV-DSA is a less invasive, simple technique to evaluate patients' condition following shunting for congenital heart diseases, as compared to the conventional method. (Namekawa, K.).
7. Patient radiation dose from computed tomography angiography and digital subtraction angiography of the brain
Netwong, Y.; Krisanachinda, A.
2016-03-01
The 64-row multidetector computed tomography angiography (64-MDCTA) provides vascular image quality of the brain similar to digital subtraction angiography (DSA), but the effective dose of CTA is lower than DSA studied in phantom. The purpose of this study is to evaluate the effective dose from 64-MDCTA and DSA. Effective dose (according to ICRP 103) from 64-MDCTA and DSA flat panel detector for cerebral vessels examination of the brain using standard protocols as recommended by the manufacturer was calculated for 30 cases of MDCTA (15 male and 15 female).The mean patient age was 49.5 (23-89) yrs. 30 cases of DSA (14 male and 16 female), the mean patient age was 46.8 (21-81) yrs. For CTA, the mean effective dose was 3.7 (2.82- 5.19) mSv. For DSA, the mean effective dose was 5.78 (3.3-10.06) mSv. The effective dose of CTA depends on the scanning protocol and scan length. Low tube current can reduce patient dose whereas the number of exposures and number of series in 3D rotational angiography (3D RA) resulted in increasing effective dose in DSA patients.
8. Clinical application of dynamic digital subtraction angiography in cerebrovascular ischemic diseases
Hirata, Yoshifumi; Nonaka, Nobuhito; Matsukado, Yasuhiko; Takahashi, Mutsumasa.
1987-09-01
Dynamic intravenous digital subtraction angiography (IV-DSA) was performed in 37 patients with cerebrovascular ischemic diseases. The time density curve of IV-DSA was analysed, and peak time, mean transit time and mode of transit time were obtained in each patient. On the basis of these values, cerebral perfusion was classified into low, normal and high perfusion patterns. Normal perfusion pattern was noted in 40% of patients with transient ischemic attack (TIA) and 7 % of patients with cerebral infarction. Low perfusion pattern was observed in 60 % of patients with TIA and 87 % of patients with cerebral infarction. High perfusion pattern was encountered only in 7 % of patients with cerebral infarction. In ischemic patients with moyamoya disease, extremely prolonged cerebral circulation time was evidenced by the presence of a flat or uphill type of the time density curve. This finding well correlated with decreased cerebral blood flow on single photon emission tomography. These findings suggest that the analysis of dynamic DSA is very important and useful in the clinical evaluation of patients with cerebrovascular ischemic diseases.
9. Remapping of digital subtraction angiography on a standard fluoroscopy system using 2D-3D registration
Alhrishy, Mazen G.; Varnavas, Andreas; Guyot, Alexis; Carrell, Tom; King, Andrew; Penney, Graeme
2015-03-01
Fluoroscopy-guided endovascular interventions are being performing for more and more complex cases with longer screening times. However, X-ray is much better at visualizing interventional devices and dense structures compared to vasculature. To visualise vasculature, angiography screening is essential but requires the use of iodinated contrast medium (ICM) which is nephrotoxic. Acute kidney injury is the main life-threatening complication of ICM. Digital subtraction angiography (DSA) is also often a major contributor to overall patient radiation dose (81% reported). Furthermore, a DSA image is only valid for the current interventional view and not the new view once the C-arm is moved. In this paper, we propose the use of 2D-3D image registration between intraoperative images and the preoperative CT volume to facilitate DSA remapping using a standard fluoroscopy system. This allows repeated ICM-free DSA and has the potential to enable a reduction in ICM usage and radiation dose. Experiments were carried out using 9 clinical datasets. In total, 41 DSA images were remapped. For each dataset, the maximum and averaged remapping accuracy error were calculated and presented. Numerical results showed an overall averaged error of 2.50 mm, with 7 patients scoring averaged errors < 3 mm and 2 patients < 6 mm.
10. [Digital subtraction angiography with carbon dioxide in severe arterial ischemia and allergy to iodinated compounds].
Calvo Cascallo, J; Mundi Salvadó, N; Cardona Fontanet, M
1993-01-01
When in some selected patients, a direct arterial surgery (DAS) procedure or an endoluminal surgery (ES) are required for a chronic arterial ischemia (III or IV degrees), and an arteriography with contrast is absolutely contraindicated (because of severe renal failure without hemodialysis program or a severe congestive heart failure or a hyperthyroidism or a seriously demonstrated hypersensibility against the contrast agents); an angiography by digital subtraction with carbon dioxide (DIVAS-CO2) is indicated. This technique provides good quality images with minimal risks for the patient and an adequate study for ulterior treatment. We report a case of a 67-years-old woman, with diabetes-II, ischemic cardiopathy, arterial hypertension and a demonstrated hypersensibility against the iodide compounds. The patient was admitted because of a chronic ischemia (IV degree) with ischemic ulcerations on some fingers from the left foot. High doses of analgesic drugs were needed. Because the hypersensibility against the iodide compounds, an angiography with CO2 was carried out. The good quality images provided by this technique showed the factibility of a revascularization.
11. A LabVIEW Platform for Preclinical Imaging Using Digital Subtraction Angiography and Micro-CT.
Badea, Cristian T; Hedlund, Laurence W; Johnson, G Allan
2013-01-01
CT and digital subtraction angiography (DSA) are ubiquitous in the clinic. Their preclinical equivalents are valuable imaging methods for studying disease models and treatment. We have developed a dual source/detector X-ray imaging system that we have used for both micro-CT and DSA studies in rodents. The control of such a complex imaging system requires substantial software development for which we use the graphical language LabVIEW (National Instruments, Austin, TX, USA). This paper focuses on a LabVIEW platform that we have developed to enable anatomical and functional imaging with micro-CT and DSA. Our LabVIEW applications integrate and control all the elements of our system including a dual source/detector X-ray system, a mechanical ventilator, a physiological monitor, and a power microinjector for the vascular delivery of X-ray contrast agents. Various applications allow cardiac- and respiratory-gated acquisitions for both DSA and micro-CT studies. Our results illustrate the application of DSA for cardiopulmonary studies and vascular imaging of the liver and coronary arteries. We also show how DSA can be used for functional imaging of the kidney. Finally, the power of 4D micro-CT imaging using both prospective and retrospective gating is shown for cardiac imaging.
12. Analysis of the venous channel within the clivus using multidetector computed tomography digital subtraction venography.
Mizutani, Katsuhiro; Toda, Masahiro; Kurasawa, Jun; Akiyama, Takenori; Fujiwara, Hirokazu; Jinzaki, Masahiro; Yoshida, Kazunari
2017-03-01
Although neuroradiologists and skull base neurosurgeons are aware of the existence of veins within the clivus, such vessels have seldom been described in the literature. The aim of the present study is to elucidate the detailed venous structure of the clivus. Computed tomography digital subtraction venography (CT-DSV) images of 50 unruptured aneurysm cases were examined retrospectively. Eighteen emissary veins were identified in 14 (28.0%) cases. A half of the emissary veins connected the inferior petrosal sinus with the inferior petro-occipital vein (IPOV) in the middle clivus. The clival diploic vein (CDV) was identified in 14.0% of cases, 42.9% of which had the clivus of the presellar type. The CDV was connected to the posterior intercavernous sinus or the rostral end of the basilar plexus superiorly, and was connected to the IPOV, anterior condylar vein, marginal sinus, or the anterior condylar confluence. The CDV provides collateral channels between the cavernous sinus and the internal jugular vein and the inferior petrosal sinus and the IPOV. Understanding of the emissary veins in the clivus and the CDV is valuable for skull base surgery, especially for endonasal endoscopic skull base procedures.
13. In vivo small-animal imaging using micro-CT and digital subtraction angiography
Badea, C T; Johnson, G A [Center for In Vivo Microscopy, Department of Radiology, Duke University, Durham, NC 27710 (United States); Drangova, M; Holdsworth, D W [Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, ON N6A 5K8 (United States)], E-mail: [email protected]
2008-10-07
Small-animal imaging has a critical role in phenotyping, drug discovery and in providing a basic understanding of mechanisms of disease. Translating imaging methods from humans to small animals is not an easy task. The purpose of this work is to review in vivo x-ray based small-animal imaging, with a focus on in vivo micro-computed tomography (micro-CT) and digital subtraction angiography (DSA). We present the principles, technologies, image quality parameters and types of applications. We show that both methods can be used not only to provide morphological, but also functional information, such as cardiac function estimation or perfusion. Compared to other modalities, x-ray based imaging is usually regarded as being able to provide higher throughput at lower cost and adequate resolution. The limitations are usually associated with the relatively poor contrast mechanisms and potential radiation damage due to ionizing radiation, although the use of contrast agents and careful design of studies can address these limitations. We hope that the information will effectively address how x-ray based imaging can be exploited for successful in vivo preclinical imaging. (topical reviews)
14. The comparative study on diagnostic validity of cerebral aneurysm by computed tomography angiography versus digital subtraction angiography after subarachnoid hemorrhage
Masih Saboori
2011-01-01
Full Text Available Background: In order to declare the preoperative diagnostic value of brain aneurysms, two radiological modalities, computed tomographic angiography and digital subtraction angiography were compared. Methods: In this descriptive analytic study, diagnostic value of computed tomographic angiography (CTA was com-pared with digital subtraction angiography (DSA. Sensitivity, specificity, positive and negative predictive values were calculated and compared between the two modalities. All data were analyzed with SPSS software, version 16. Results: Mean age of patients was 49.5 ± 9.13 years. 57.9 % of subjects were female. CTA showed 89% sensitivity and 100% specificity whereas DSA demonstrated 74% sensitivity and 100% specificity. Positive predictive value of both methods was 100%, but negative predictive value of CTA and DSA was 85% and 69%, respectively. Conclusions: Based on our data, CTA is a valuable diagnostic modality for detection of brain aneurysm and su-barachnoid hemorrhage.
15. Minimally Invasive Monitoring of Chronic Central Venous Catheter Patency in Mice Using Digital Subtraction Angiography (DSA.
Giovanna Figueiredo
Full Text Available Repetitive administration of medication or contrast agents is frequently performed in mice. The introduction of vascular access mini-ports (VAMP for mice allows long-term vascular catheterization, hereby eliminating the need for repeated vessel puncture. With catheter occlusion being the most commonly reported complication of chronic jugular vein catheterization, we tested whether digital subtraction angiography (DSA can be utilized to evaluate VAMP patency in mice.Twenty-three mice underwent catheterization of the jugular vein and subcutaneous implantation of a VAMP. The VAMP was flushed every second day with 50 μL of heparinized saline solution (25 IU/ml. DSA was performed during injection of 100 μL of an iodine based contrast agent using an industrial X-ray inspection system intraoperatively, as well as 7±2 and 14±2 days post implantation.DSA allowed localization of catheter tip position, to rule out dislocation, kinking or occlusion of a microcatheter, and to evaluate parent vessel patency. In addition, we observed different ante- and retrograde collateral flow patterns in case of jugular vein occlusion. More exactly, 30% of animals showed parent vessel occlusion after 7±2 days in our setting. At this time point, nevertheless, all VAMPs verified intravascular contrast administration. After 14±2 days, intravascular contrast injection was verified in 70% of the implanted VAMPs, whereas at this point of time 5 animals had died or were sacrificed and in 2 mice parent vessel occlusion hampered intravascular contrast injection. Notably, no occlusion of the catheter itself was observed.From our observations we conclude DSA to be a fast and valuable minimally invasive tool for investigation of catheter and parent vessel patency and for anatomical studies of collateral blood flow in animals as small as mice.
16. Vascular invasion of klatskin tumor : computed tomography vs digital subtraction angiography in determining resectability
Cha, Joo Hee; Han, Joon Koo; Kim, Tae Kyoung; Sin, Sang Jun; Hong, Hye Sook; Park, Jae Hyung; Choi, Byung Ihn; Kim, Sun Whe [College of Medicine, the Institute of Radiation Medicine, Seoul National University, Seoul (Korea, Republic of); Song, Chi Sung [Borame Hospital, Seoul (Korea, Republic of)
2000-02-01
To compare the accuracy of computed tomography (CT) with that of digital subtraction angiography (DSA) in predicting the resectability of Klatskin tumor on the basis of vascular invasion. Twenty-five patients with Klatskin tumor who had undergone laparotomy were included in this study. In order to assess the surgical resectability of their tumors, the preoperative CT scans and DSA of these patients were retrospectively assessed in terms of vascular invasion. The criteria of unresectability were tumoral invasion of the proper hepatic artery or main portal vein, or simultaneous invasion of the hepatic artery on one side and the other side portal vein. Tumors were unresectable in 13 cases, and resectable in 12. CT and DSA predicted nine and three tumors as unresectable ones, respectively. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of CT in determining whether a tumor was unresectable were 61.5%, 91.7%, 88.9%, 68.8% and 76.0%, respectively. For DSA, the respective figures were 23.1%, 100%, 100%, 54.5%, and 60%. For the detection of vascular invasion without diameter change, CT was superior to DSA; for the evaluation of vascular anatomy, it was, however, less effective. CT failed to detect small hepatic metastasis (n=3D2), lymph node metastasis (n=3D1), variation of the bile duct (n=3D1), and the distal extent of tumor in the bile duct (n=3D1), factors which precluded surgical resection. CT is a reliable method for the detection of vascular invasion and tumor unresectability. For the detection of vascular anatomic variation, the combined use of CT and DSA would be helpful. (author)
17. Quantitative blood flow measurements in the small animal cardiopulmonary system using digital subtraction angiography
Lin Mingde; Marshall, Craig T.; Qi, Yi; Johnston, Samuel M.; Badea, Cristian T.; Piantadosi, Claude A.; Johnson, G. Allan [Department of Radiology, Center for In Vivo Microscopy and Department of Biomedical Engineering, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Division of Pulmonary and Critical Care Medicine and Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Box 3823, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy and Department of Biomedical Engineering, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Division of Pulmonary and Critical Care Medicine and Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Box 3823, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy and Department of Biomedical Engineering, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States)
2009-11-15
Purpose: The use of preclinical rodent models of disease continues to grow because these models help elucidate pathogenic mechanisms and provide robust test beds for drug development. Among the major anatomic and physiologic indicators of disease progression and genetic or drug modification of responses are measurements of blood vessel caliber and flow. Moreover, cardiopulmonary blood flow is a critical indicator of gas exchange. Current methods of measuring cardiopulmonary blood flow suffer from some or all of the following limitations--they produce relative values, are limited to global measurements, do not provide vasculature visualization, are not able to measure acute changes, are invasive, or require euthanasia. Methods: In this study, high-spatial and high-temporal resolution x-ray digital subtraction angiography (DSA) was used to obtain vasculature visualization, quantitative blood flow in absolute metrics (ml/min instead of arbitrary units or velocity), and relative blood volume dynamics from discrete regions of interest on a pixel-by-pixel basis (100x100 {mu}m{sup 2}). Results: A series of calibrations linked the DSA flow measurements to standard physiological measurement using thermodilution and Fick's method for cardiac output (CO), which in eight anesthetized Fischer-344 rats was found to be 37.0{+-}5.1 ml/min. Phantom experiments were conducted to calibrate the radiographic density to vessel thickness, allowing a link of DSA cardiac output measurements to cardiopulmonary blood flow measurements in discrete regions of interest. The scaling factor linking relative DSA cardiac output measurements to the Fick's absolute measurements was found to be 18.90xCO{sub DSA}=CO{sub Fick}. Conclusions: This calibrated DSA approach allows repeated simultaneous visualization of vasculature and measurement of blood flow dynamics on a regional level in the living rat.
18. Clinical applications of MR digital subtraction angiography for the evaluation of intracranial vascular and tumorous lesions
Katase, Shichiro; Tsuchiya, Kazuhiro; Hachiya, Junichi [Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine
2001-07-01
MR digital subtraction angiography (MR DSA), which is performed by a rapid two-dimensional T1-weighted sequence in combination with bolus injection of gadolinium-based contrast agent was applied to the evaluation of cerebral arteriovenous malformations (AVMs), brain tumors (intraaxial and extraaxial tumors), and other vascular lesions. This study was performed to evaluate the clinical usefulness of the method in the diagnosis of these lesions. We studied 19 cases of cerebral AVM, 36 cases of intraaxial tumor (metastatic brain tumors in 14, glioblastomas in five, astrocytomas in eight, malignant lymphomas in four, pineal tumors in two, and other tumors, in three), 34 cases of extraaxial tumor (meningiomas in 29, and pituitary adenomas in five), and 10 cases of other vascular lesions (cerebral aneurysms in five, venous thrombosis in two, and other lesion in three). For cerebral AVMs, the feeder, nidus, and drainer were evaluated on a 4 - point grading scale (0=poor, 1=fair, 2=good, 3=excellent), and the results obtained were compared with those of conventional cerebral angiography or MR angiography using the postcontrast three-dimensional time-of-flight method. Brain tumors were classified into six enhancement patterns, and were compared with the findings of conventional cerebral angiography. Other vascular lesions were assessed visually. All cases were evaluated independently by two radiologists, and inter-observer agreement was assessed using the {kappa}-test. In all cerebral AVM cases, the hemodynamics of the feeder, nidus, and drainer could be observed. In all but five brain tumor cases, tumor stain could be confirmed in MR DSA images. The findings of tumor stain corresponded to those of cerebral angiographic images. For other vascular lesions, results of lesion detection and lesion morphology were almost in congruence with other methods. MR DSA provides information on the hemodynamics of vascular and tumorous lesions. When used in conjunction with routine MR
19. Classification-based summation of cerebral digital subtraction angiography series for image post-processing algorithms
Schuldhaus, D; Spiegel, M; Polyanskaya, M; Hornegger, J [Pattern Recognition Lab, University Erlangen-Nuremberg (Germany); Redel, T [Siemens AG Healthcare Sector, Forchheim (Germany); Struffert, T; Doerfler, A, E-mail: [email protected] [Department of Neuroradiology, University Erlangen-Nuremberg (Germany)
2011-03-21
X-ray-based 2D digital subtraction angiography (DSA) plays a major role in the diagnosis, treatment planning and assessment of cerebrovascular disease, i.e. aneurysms, arteriovenous malformations and intracranial stenosis. DSA information is increasingly used for secondary image post-processing such as vessel segmentation, registration and comparison to hemodynamic calculation using computational fluid dynamics. Depending on the amount of injected contrast agent and the duration of injection, these DSA series may not exhibit one single DSA image showing the entire vessel tree. The interesting information for these algorithms, however, is usually depicted within a few images. If these images would be combined into one image the complexity of segmentation or registration methods using DSA series would drastically decrease. In this paper, we propose a novel method automatically splitting a DSA series into three parts, i.e. mask, arterial and parenchymal phase, to provide one final image showing all important vessels with less noise and moving artifacts. This final image covers all arterial phase images, either by image summation or by taking the minimum intensities. The phase classification is done by a two-step approach. The mask/arterial phase border is determined by a Perceptron-based method trained from a set of DSA series. The arterial/parenchymal phase border is specified by a threshold-based method. The evaluation of the proposed method is two-sided: (1) comparison between automatic and medical expert-based phase selection and (2) the quality of the final image is measured by gradient magnitudes inside the vessels and signal-to-noise (SNR) outside. Experimental results show a match between expert and automatic phase separation of 93%/50% and an average SNR increase of up to 182% compared to summing up the entire series.
20. Classification-based summation of cerebral digital subtraction angiography series for image post-processing algorithms
Schuldhaus, D.; Spiegel, M.; Redel, T.; Polyanskaya, M.; Struffert, T.; Hornegger, J.; Doerfler, A.
2011-03-01
X-ray-based 2D digital subtraction angiography (DSA) plays a major role in the diagnosis, treatment planning and assessment of cerebrovascular disease, i.e. aneurysms, arteriovenous malformations and intracranial stenosis. DSA information is increasingly used for secondary image post-processing such as vessel segmentation, registration and comparison to hemodynamic calculation using computational fluid dynamics. Depending on the amount of injected contrast agent and the duration of injection, these DSA series may not exhibit one single DSA image showing the entire vessel tree. The interesting information for these algorithms, however, is usually depicted within a few images. If these images would be combined into one image the complexity of segmentation or registration methods using DSA series would drastically decrease. In this paper, we propose a novel method automatically splitting a DSA series into three parts, i.e. mask, arterial and parenchymal phase, to provide one final image showing all important vessels with less noise and moving artifacts. This final image covers all arterial phase images, either by image summation or by taking the minimum intensities. The phase classification is done by a two-step approach. The mask/arterial phase border is determined by a Perceptron-based method trained from a set of DSA series. The arterial/parenchymal phase border is specified by a threshold-based method. The evaluation of the proposed method is two-sided: (1) comparison between automatic and medical expert-based phase selection and (2) the quality of the final image is measured by gradient magnitudes inside the vessels and signal-to-noise (SNR) outside. Experimental results show a match between expert and automatic phase separation of 93%/50% and an average SNR increase of up to 182% compared to summing up the entire series.
1. A 2D driven 3D vessel segmentation algorithm for 3D digital subtraction angiography data
Spiegel, M; Hornegger, J [Pattern Recognition Lab, University Erlangen-Nuremberg, Erlangen (Germany); Redel, T [Siemens AG Healthcare Sector, Forchheim (Germany); Struffert, T; Doerfler, A, E-mail: [email protected] [Department of Neuroradiology, University Erlangen-Nuremberg, Erlangen (Germany)
2011-10-07
Cerebrovascular disease is among the leading causes of death in western industrial nations. 3D rotational angiography delivers indispensable information on vessel morphology and pathology. Physicians make use of this to analyze vessel geometry in detail, i.e. vessel diameters, location and size of aneurysms, to come up with a clinical decision. 3D segmentation is a crucial step in this pipeline. Although a lot of different methods are available nowadays, all of them lack a method to validate the results for the individual patient. Therefore, we propose a novel 2D digital subtraction angiography (DSA)-driven 3D vessel segmentation and validation framework. 2D DSA projections are clinically considered as gold standard when it comes to measurements of vessel diameter or the neck size of aneurysms. An ellipsoid vessel model is applied to deliver the initial 3D segmentation. To assess the accuracy of the 3D vessel segmentation, its forward projections are iteratively overlaid with the corresponding 2D DSA projections. Local vessel discrepancies are modeled by a global 2D/3D optimization function to adjust the 3D vessel segmentation toward the 2D vessel contours. Our framework has been evaluated on phantom data as well as on ten patient datasets. Three 2D DSA projections from varying viewing angles have been used for each dataset. The novel 2D driven 3D vessel segmentation approach shows superior results against state-of-the-art segmentations like region growing, i.e. an improvement of 7.2% points in precision and 5.8% points for the Dice coefficient. This method opens up future clinical applications requiring the greatest vessel accuracy, e.g. computational fluid dynamic modeling.
2. Classification-based summation of cerebral digital subtraction angiography series for image post-processing algorithms.
Schuldhaus, D; Spiegel, M; Redel, T; Polyanskaya, M; Struffert, T; Hornegger, J; Doerfler, A
2011-03-21
X-ray-based 2D digital subtraction angiography (DSA) plays a major role in the diagnosis, treatment planning and assessment of cerebrovascular disease, i.e. aneurysms, arteriovenous malformations and intracranial stenosis. DSA information is increasingly used for secondary image post-processing such as vessel segmentation, registration and comparison to hemodynamic calculation using computational fluid dynamics. Depending on the amount of injected contrast agent and the duration of injection, these DSA series may not exhibit one single DSA image showing the entire vessel tree. The interesting information for these algorithms, however, is usually depicted within a few images. If these images would be combined into one image the complexity of segmentation or registration methods using DSA series would drastically decrease. In this paper, we propose a novel method automatically splitting a DSA series into three parts, i.e. mask, arterial and parenchymal phase, to provide one final image showing all important vessels with less noise and moving artifacts. This final image covers all arterial phase images, either by image summation or by taking the minimum intensities. The phase classification is done by a two-step approach. The mask/arterial phase border is determined by a Perceptron-based method trained from a set of DSA series. The arterial/parenchymal phase border is specified by a threshold-based method. The evaluation of the proposed method is two-sided: (1) comparison between automatic and medical expert-based phase selection and (2) the quality of the final image is measured by gradient magnitudes inside the vessels and signal-to-noise (SNR) outside. Experimental results show a match between expert and automatic phase separation of 93%/50% and an average SNR increase of up to 182% compared to summing up the entire series.
3. Estimating breast thickness for dual-energy subtraction in contrast-enhanced digital mammography using calibration phantoms
Lau, Kristen C.; Kwon, Young Joon; Aziz, Moez Karim; Acciavatti, Raymond J.; Maidment, Andrew D. A.
2016-04-01
Dual-energy contrast-enhanced digital mammography (DE CE-DM) uses an iodinated contrast agent to image the perfusion and vasculature of the breast. DE images are obtained by a weighted logarithmic subtraction of the high-energy (HE) and low-energy (LE) image pairs. We hypothesized that the optimal DE subtraction weighting factor is thickness-dependent, and developed a method for determining breast tissue composition and thickness in DE CE-DM. Phantoms were constructed using uniform blocks of 100% glandular-equivalent and 100% adipose-equivalent material. The thickness of the phantoms ranged from 3 to 8 cm, in 1 cm increments. For a given thickness, the glandular-adipose composition of the phantom was varied using different combinations of blocks. The logarithmic LE and logarithmic HE signal intensities were measured; they decrease linearly with increasing glandularity for a given thickness. The signals decrease with increasing phantom thickness and the x-ray signal decreases linearly with thickness for a given glandularity. As the thickness increases, the attenuation difference per additional glandular block decreases, indicating beam hardening. From the calibration mapping, we have demonstrated that we can predict percent glandular tissue and thickness when given two distinct signal intensities. Our results facilitate the subtraction of tissue at the boundaries of the breast, and aid in discriminating between contrast agent uptake in glandular tissue and subtraction artifacts.
4. Projection-based energy weighting on photon-counting X-ray images in digital subtraction mammography: a feasibility study
Choi, Sung-Hoon; Lee, Seung-Wan; Choi, Yu-Na; Lee, Young-Jin; Kim, Hee-Joung
2014-03-01
In digital subtraction mammography where subtracts the one image (with contrast medium) from the other (anatomical background) for observing the tumor structure, tumors which include more blood vessels than normal tissue could be distinguished through the enhancement of contrast-to-noise ratio (CNR). In order to improve CNR, we adopted projection-based energy weighting for iodine solutions with four different concentrations embedded in a breast phantom (50% adipose and 50% glandular tissues). In this study, a Monte Carlo simulation was used to simulate a 40 mm thickness breast phantom, which has 15 and 30 mg/cm3 iodine solutions with two different thicknesses, and an energy resolving photon-counting system. The input energy spectrum was simulated in a range of 20 to 45 keV in order to reject electronic noise and include k-edge energy of iodine (33.2 keV). The results showed that the projection-based energy weighting improved the CNR by factors of 1.05-1.86 compared to the conventional integrating images. Consequently, the CNR of images from the digital subtraction mammography could be improved by the projection-based energy weighting with photon-counting detectors.
5. Comparison of conventional panoramic radiography and panoramic digital subtraction radiography in detection of simulated lesions of mandibular condyle
Panjnoush M.
2008-12-01
Full Text Available "n "nBackground and Aim: Digital subtraction Radiography (DSR is a method of accurate assessing condylar head changes. several studies have been carried out in applying DSR in dentistry, however there is a few number of studies in efficacy of DSR method in assesment of condylar head changes, The aim of this study was to compare panoramic radiography and DSR detecting simulated lesions of the mandibular condyl. "nMaterials and Methods: this was a process reaserch study, in which two dry human skulls with no obvious temporomandibular joint pathology were used. Osteophytic lesions were simulated using three sizes of bone chips that were placed on the medial portion of anterior and superolateral aspects of the condyle. Osteolytic lesions were simulated making 1 and 2 mm holes using round burr in the central portion of anterior aspect and Lateral pole of the condyle. Panoramic radiographs were prepared with and without the lesions in place. These paired radiographs were digitized and digital- subtraction images of the original panoramic images were obtained. Eight observers evaluated 155 images of each modality for the presence or absence and the type of simulated lesions of the mandibular condyle. Sensitivity, specificity, reliability and measure of agreement were analyzed using kappa test and crossed tables and qualitative variables were assess by chi-square and fisher's Exact test. "nResults: Specificity of panoramic and DSR methods were 15.4% and 66.7% respectively. Sensitivity of panoramic and DSR methods were 61.1% and 80.6% for osteophytic lesions and 37.5% and 83.3% for Osteolytic lesions. The percentage of correct decisions made in DSR method was significantly more than conventional panoramic method (82.6% vs 41.9% (p<0.0001. "nConclusion: Based on the results of this study digital subtraction technique was significantly more accurate than the panoramic radiographs in detection of simulated lesions of the mandibular condyle.
6. Digital subtraction radiographic analysis of the combination of bioabsorbable membrane and bovine morphogenetic protein pool in human periodontal infrabony defects
2010-08-01
Full Text Available OBJECTIVES: This study assessed the bone density gain and its relationship with the periodontal clinical parameters in a case series of a regenerative therapy procedure. MATERIAL AND METHODS: Using a split-mouth study design, 10 pairs of infrabony defects from 15 patients were treated with a pool of bovine bone morphogenetic proteins associated with collagen membrane (test sites or collagen membrane only (control sites. The periodontal healing was clinically and radiographically monitored for six months. Standardized pre-surgical and 6-month postoperative radiographs were digitized for digital subtraction analysis, which showed relative bone density gain in both groups of 0.034 ± 0.423 and 0.105 ± 0.423 in the test and control group, respectively (p>0.05. RESULTS: As regards the area size of bone density change, the influence of the therapy was detected in 2.5 mm² in the test group and 2 mm² in the control group (p>0.05. Additionally, no correlation was observed between the favorable clinical results and the bone density gain measured by digital subtraction radiography (p>0.05. CONCLUSIONS: The findings of this study suggest that the clinical benefit of the regenerative therapy observed did not come with significant bone density gains. Long-term evaluation may lead to a different conclusions.
7. Multimodality evaluation of dural arteriovenous fistula with CT angiography, MR with arterial spin labeling, and digital subtraction angiography: case report.
Alexander, Matthew; McTaggart, Ryan; Santarelli, Justin; Fischbein, Nancy; Marks, Michael; Zaharchuk, Greg; Do, Huy
2014-01-01
Dural arteriovenous fistulae (DAVF) are cerebrovascular lesions with pathologic shunting into the venous system from arterial feeders. Digital subtraction angiography (DSA) has long been considered the gold standard for diagnosis, but advances in noninvasive imaging techniques now play a role in the diagnosis of these complex lesions. Herein, we describe the case of a patient with right-side pulsatile tinnitus and DAVF diagnosed using computed tomography angiography, magnetic resonance with arterial spin labeling, and DSA. Implications for imaging analysis of DAVFs and further research are discussed.
8. [X-ray semiotics of sialolithiasis in functional digital subtraction sialography].
Iudin, L A; Kondrashin, S A; Afanas'ev, V V; Shchipskiĭ, A V
1995-01-01
Twenty-seven patients with sialolithiasis were examined using functional subtraction sialography developed by the authors. Differential diagnostic signs characterizing the degree of involvement of the salivary gland were defined. High efficacy of the method helps correctly plan the treatment strategy.
9. Clinical value of three-dimensional digital subtraction angiography in the endovascular treatment of intracranial aneurysms
Tianxiao Li; Dengwei Zong
2006-01-01
BACKGROUND: The endovascular treatment of intracranial aneurysms requires clearly displayed anatomic structures of the aneurysm and the reference image of the aneurysm neck, the images of the form and struc ture of the aneurysm and the three-dimensional (3D) intracranial vascular structure are very important for the diagnosis and treatment of cerebral aneurysms. OBJECTIVE: To investigate the value of 3D digital subtraction angiography (3D DSA) in diagnosing intracra nial aneurysm, and compare the reliability with two-dimensional (2D) DSA in evaluating the intracranial aneurysm suitable for the endovascular occlusion: DESIGN: A double-blind case observation. SETTING: Department of Interventional Radiology, Henan People's Hospital. PARTICIPANTS: The patients, who were suspected to have intracranial aneurysms, were examined with 2D DSA and 3D DSA in Henan People's Hospital from October 2004 to October 2005. Fifty intracranial aneurysms were detected in 44 patients (19 males and 25 females) of 30-75 years, with an average of 51 years, including 5 cases were multiple aneurysms, including 2 aneurysms in 4 cases and 3 aneurysms in 1 case. The aneurysms located respectively at internal carotid artery (n =19), anterior cerebral artery (n =16), middle cerebral artery (n =8), basilar artery (n =6), and posterior inferior cerebellar artery (n =1 ). METHODS: The 50 ruptured intracranial aneurysms were examined with 2D DSA and 3D DSA. The method of volume reconstruction was applied to reconstruct the 3D DSA images, and the automatically generated images could be shifted, rotated and magnified, besides, the corresponding processing could also be performed, including resecting the unnecessary structure and sharpening margin of the images. Observations: ① Display of aneurysm neck: The site and range of the aneurysm neck, and the involvement of branches originated from the aneurysm arteries; ② Display of aneurysm form: The displays of aneurysm form and with or without arteries
10. Three-dimensional volume rendering digital subtraction angiography in comparison with two-dimensional digital subtraction angiography and rotational angiography for detecting aneurysms and their morphological properties in patients with subarachnoid hemorrhage
Kucukay, Fahrettin, E-mail: [email protected] [Turkiye Yuksek Ihtisas Hospital, Department of Radiology, Ankara (Turkey); Okten, R. Sarper [Turkiye Yuksek Ihtisas Hospital, Department of Radiology, Ankara (Turkey); Tekiner, Ayhan [Ankara Education and Teaching Hospital, Department of Neurosurgery, Ankara (Turkey); Dagli, Mustafa [Turkiye Yuksek Ihtisas Hospital, Department of Radiology, Ankara (Turkey); Gocek, Cevdet; Bayar, Mehmet Akif [Ankara Education and Teaching Hospital, Department of Neurosurgery, Ankara (Turkey); Cumhur, Turhan [Turkiye Yuksek Ihtisas Hospital, Department of Radiology, Ankara (Turkey)
2012-10-15
Objective: Subarachnoid hemorrhage (SAH), which can cause mortality and severe morbidity, is a serious condition whose underlying cause must be determined. We aimed to compare 2D digital subtraction angiography (2DDSA), rotational angiography (RA) and 3D volume rendering digital subtraction angiography (3DVRDSA) for detecting aneurysms and their morphological properties in patients with subarachnoid hemorrhage. Materials and methods: After an initial diagnosis of SAH with computed tomography, 122 patients (52 males and 70 females with a mean age of 47.77 ± 12.81 ranging between 20 and 83 years) underwent 2DDSA imaging, RA and 3DVRDSA imaging for detection of aneurysms. The location of the aneurysm, the best working angles, the dome/neck ratios, the largest diameter of the aneurysm, the shape of the aneurysm, the presence of spasms or pseudostenoses, and the relationship to the neighboring arteries were recorded. Results: 2DDSA missed 15.6% of the aneurysms that had a mean size of 2.79 ± 0.74 mm. RA was superior to 2DDSA for detecting aneurysm neck, and 3DVRDSA was superior to RA for detecting aneurysm neck. 3DVRDSA conclusively depicted the shape of the aneurysms in all patients. 3DVRDSA imaging was superior to 2DDSA and RA in the detection of the aneurysm relationship to neighboring arteries. The sensitivity and specificity of 3DVRDSA imaging for the detection of vasospasms were 100 and 84%, respectively. Conclusions: 3DVRDSA imaging is superior to 2DDSA and RA for detecting intracranial aneurysms and their morphological properties, especially those of small, ruptured aneurysms. However, 2DDSA should not be neglected in cases of vasospasm.
11. Subtraction CT angiography for evaluation of intracranial aneurysms: comparison with conventional CT angiography
Li, Qi; Li, Kewei; Xie, Peng [The First Affiliated Hospital, Chongqing Medical University, Department of Neurology, Chongqing (China); Lv, Fajin; Li, Yongmei; Luo, Tianyou [The First Affiliated Hospital, Chongqing Medical University, Department of Radiology, Chongqing (China)
2009-09-15
The purpose of our study was to compare the diagnostic performance of subtraction computed tomography angiography (CTA) with conventional nonsubtracted CTA and digital subtraction angiography (DSA) for the detection of intracranial aneurysms. A total of 76 patients underwent both subtraction CTA and conventional CTA for the detection and therapy planning of suspected intracranial aneurysms. Subtraction and conventional CTA images were independently assessed by two readers in a blinded manner. The possibility of endovascular treatment or surgical clipping was also assessed based on information provided by CT angiograms alone. In 64 patients, 75 aneurysms were present on DSA. On a per-aneurysm basis, the sensitivity of subtraction CTA was 98.6% for reader 1, and 100% for reader 2. However, sensitivity of conventional CTA was 94.6% for reader 1, and 93.3% for reader 2. Therapeutic decisions could be made regarding 63 patients based on information provided by subtraction CTA images. However, conventional CTA provided sufficient information to make this decision for 55 patients. Conventional CTA has limited sensitivity in detecting very small aneurysms as well as aneurysms adjacent to bone. Subtraction CTA performed on a 64-row multidetector CT is an accurate and promising diagnostic tool that seems to be equivalent to 2D DSA for the detection and pretreatment planning of intracranial aneurysms. (orig.)
12. Evaluation of the lower limb vasculature before free fibula flap transfer. A prospective blinded comparison between magnetic resonance angiography and digital subtraction angiography
Klein, Steven; Van Lienden, Krijn P; Van't Veer, Marcel; Smit, Jeroen M; Werker, Paul M N
2013-01-01
Introduction The aim of this study was to compare magnetic resonance angiography (MRA) with digital subtraction angiography (DSA) in the preoperative assessment of crural arteries and their skin perforators prior to free fibular transfer. Patients and methods Fifteen consecutive patients, scheduled
13. A feasibility study of projection-based energy weighting based on a photon-counting detector in contrast-enhanced digital subtraction mammography: A simulation study
Choi, Sunghoon; Lee, Seungwan; Choi, Yu-Na; Kim, Hee-Joung
2014-06-01
Contrast media, such as iodine and gadolinium, are generally used in digital subtraction mammography to enhance the contrast between target and background materials. In digital subtraction mammography, where one image (with contrast medium) is subtracted from another (anatomical background) to facilitate visualization of the tumor structure, tumors can be more easily distinguished after the injection of a contrast medium. In order to have more an effective method to increase the contrast-to-noise ratio (CNR), we applied a projection-based energy-weighting method. The purpose of this study is to demonstrate the feasibility of using the projection-based energy-weighting method in digital subtraction mammography. Unlike some other previous studies, we applied the projection-based energy-weighting method to more practical mammography conditions by using the Monte Carlo method to simulate four different iodine solutions embedded in a breast phantom comprised of 50% adipose and 50% glandular tissues. We also considered an optimal tube voltage and anode/filter combination in digital iodine contrast media mammography in order to maximize the figure-of-merit (FOM). The simulated source energy was from 20 to 45 keV to prevent electronic noise and include the k-edge energy of iodine (33.2 keV). The results showed that the projection-based energy-weighting improved the CNR by factors of 1.05-1.86 compared to the conventionally integrated images. Consequently, the CNR of digital subtraction mammography images can be improved by using projection-based energy-weighting with photon-counting detectors.
14. Suppression of high-density artifacts in x-ray CT images using temporal digital subtraction with application to cryotherapy
Baissalov, Roustem; Sandison, George A.; Donnelly, Bryan J.; Saliken, John C.; Muldrew, Ken; Rewcastle, John C.
2000-06-01
Image guidance of cryotherapy is usually performed using ultrasound or x-ray CT. Despite the ability of CT to display the full 3D structure of the iceball, including frozen and unfrozen regions, the quality of the images is compromised by the presence of high density streak artifacts. To suppress these artifacts we applied Temporal Digital Subtraction (TDS). This TDS method has the added advantage of improving the gray scale contrast between frozen and unfrozen tissue in the CT images. Two sets of CT images were taken of a phantom material, cryoprobes and a urethral warmer (UW) before and during the cryoprobe freeze cycle. The high density artifacts persisted in both image sets. TDS was performed on these two image sets using the corresponding mask image of unfrozen material and the same geometrical configuration of the cryoprobes and the UW. The resultant difference image had a significantly reduced content of the artifacts. This TDS can be used in x-ray CT assisted cryotherapy to significantly suppress or eliminate high density x-ray CT streak artifacts by digitally processing x-ray CT images. Applying TDS in cryotherapy will facilitate estimation of the amount and location of all frozen and unfrozen regions, potentially making cryotherapy safer and less operator dependent.
15. A quantitative study of bone repair after endodontic therapy on digital subtraction radiography
Kim, Jae Duk [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Chosun University, Kwangju (Korea, Republic of)
1997-08-15
This study was performed to prepare the quantitative method of judging the sensitive prognosis of chronic apical periodontitis as early as possible. The subjects were 25 cases with periapical radiolucencies of which were treated with endodontic treatment. Serial radiographs were taken by standardized method longitudinally. The density slice function of digital radiographic system were employed for quantitative and longitudinal assessment of the radiolucent area and the condensing osteitis simultaneously. Obtained results were as follows: 1. The amount of bone repair after endodontic treatment could be detected quantitatively by the density slice function of digital radiographic system. 2. Within the 6-week period after root canal filling, the prognosis could be evaluated by assessment both radiolucent area and condensing osteitis on digital radiographic system. 3. The pattern of bone repair showed peripheral type in most cases from the 6th week after root canal filling. 4. In longitudinal change, bone repair showed two patterns; the succeeding reduction of radiolucent area showing the increase of condensing osteitis in size till 6th week and following by static state or reduction tendency and the reduction following the initial increase of both areas. 5. Cases with pulpitis by trauma showed initial increase of condensing osteitis at 2nd week, marked reduction of radiolucent area and condensing osteitis at 6th week, and approximately normal bone state at 8th week after root canal filling.
16. Evaluation of the pedal artery: comparison of three-dimensional gadolinium-enhanced MR angiography with digital subtraction angiography
Lee, Jeong Min; Kang, Sung Gwon; Byun, Joo Nam; Kim, Young Cheol; Choi, Jeong Yeol; Kim, Dong Hyun [College of Medicine, Chosun Univ., Kwangju (Korea, Republic of)
2002-07-01
To compare the three-dimensional gadolinium-enhanced MR angiography with digital subtraction angiography (DSA) for evaluation of the pedal artery. In 12 extremities of 11 patients, both digital subtraction angiography (DSA) and contrast-enhanced MR angiography (CE-MR angiography) were performed during the same week. Among ten of the 11 patients, the following conditions were present: atherosclerosis (n=4), diabetic foot (n=3), Buerger's disease (n=1), calciphylactic arteriopathy (n=1) and arteriovenous malformation of the foot (n=1). The remaining patient underwent angiography prior to flap surgery. For MR angiography, a 1.5T system using an extremity or head coil was used. A three-dimensional FISP (fast imaging with steady state precession) sequence was obtained before enhancement, followed by four sequential acquisitions (scan time, 20 secs, scan interval time, 10 secs) 10 seconds after intravenous bolus injection of normal saline (total 10 cc), following intravenous administration of gadolinium (0.02 mmol/kg, 3 ml/sec). Arterial segments of the ankle and foot were classified as the anterior or posterior tibial artery, the distal peroneal artery, the medial or lateral plantar artery, the pedal arch, and the dorsalis pedis artery. Two radiologists independently analysed visualization of each arteraial segment and the mean of visible arterial segments in one extreminty using CE-MR angiography and DSA. Among 84 arterial segments, 16 were invisible at both CE-MR angiography and DSA, while 39 were demonstrated by both modalities. Twenty-six segments were visible only at CE-MR angiography and three only at DSA. CE-MR angiography displayed a higher number of arterial segments than DSA (mean, 5.42 vs. mean 3.50, respectively), a difference which was statistically significant (p<0.000). The difference between each arterial segment was not statistically significant, except for the dorsalis pedis artery (t test, p<0.000). In that it provides additional information for
Larwin, K. H.; Thomas, Eugene M.; Larwin, David A.
2015-01-01
This paper introduces a new term and concept to the leadership discourse: Subtractive Leadership. As an extension of the distributive leadership model, the notion of subtractive leadership refers to a leadership style that detracts from organizational culture and productivity. Subtractive leadership fails to embrace and balance the characteristics…
18. Use of cone-beam tomography and digital subtraction radiography for diagnosis and evaluation of traumatized teeth treated with endodontic surgery and MTA. A case report.
de Carvalho, Fabíola Bastos; Gonçalves, Paloma Souza; Lima, Regina Karla de Pontes; Guerreiro-Tanomaru, Juliane Maria; Rasquin, Luis Cardoso; Tanomaru-Filho, Mário
2013-10-01
The aim of this paper was to report the diagnosis and evaluation of periradicular bone repair by using computed tomography and digital subtraction radiography in an endodontic surgery case treated with mineral trioxide aggregate (MTA). The patient had local swelling and fistula 7 years after trauma in the upper jaw. Periapical lesion on tooth #12 and root resorption of tooth #11 were detected radiographically. Endodontic therapy and placement of intracanal medication were carried out. After 3 months, with no improvement in the clinical signs and symptoms, computed tomography was performed, showing extensive apical bone resorption on tooth #12 and dental resorption promoting communication of the root canal with the periodontium of tooth #11. The patient was referred to endodontic surgery. After surgery and postoperative periods of 15, 30, 60, 90, and 120 days, standardized radiographs were taken, digitized, and subjected to digital subtraction of the images using Adobe Photoshop CS software. Four years later, a cone-beam computed tomography was performed, showing bone repair and absence of root resorption at tooth #11. In this clinical case, digital subtraction radiography was effective for early detection of new bone formation and evolution of repair. © 2011 John Wiley & Sons A/S.
19. Cerebral Circulation Time is Prolonged and Not Correlated with EDSS in Multiple Sclerosis Patients: A Study Using Digital Subtracted Angiography
Monti, Lucia; Donati, Donatella; Menci, Elisabetta; Cioni, Samuele; Bellini, Matteo; Grazzini, Irene; Leonini, Sara; Galluzzi, Paolo; Severi, Sauro; Burroni, Luca; Casasco, Alfredo; Morbidelli, Lucia; Santarnecchi, Emiliano; Piu, Pietro
2015-01-01
Literature has suggested that changes in brain flow circulation occur in patients with multiple sclerosis. In this study, digital subtraction angiography (DSA) was used to measure the absolute CCT value in MS patients and to correlate its value to age at disease onset and duration, and to expand disability status scale (EDSS). DSA assessment was performed on eighty MS patients and on a control group of forty-four age-matched patients. CCT in MS and control groups was calculated by analyzing the angiographic images. Lesion and brain volumes were calculated in a representative group of MS patients. Statistical correlations among CCT and disease duration, age at disease onset, lesion load, brain volumes and EDSS were considered. A significant difference between CCT in MS patients (mean = 4.9s; sd = 1.27s) and control group (mean = 2.8s; sd = 0.51s) was demonstrated. No significant statistical correlation was found between CCT and the other parameters in all MS patients. Significantly increased CCT value in MS patients suggests the presence of microvascular dysfunctions, which do not depend on clinical and MRI findings. Hemodynamic changes may not be exclusively the result of a late chronic inflammatory process. PMID:25679526
20. Cerebral circulation time is prolonged and not correlated with EDSS in multiple sclerosis patients: a study using digital subtracted angiography.
Lucia Monti
Full Text Available Literature has suggested that changes in brain flow circulation occur in patients with multiple sclerosis. In this study, digital subtraction angiography (DSA was used to measure the absolute CCT value in MS patients and to correlate its value to age at disease onset and duration, and to expand disability status scale (EDSS. DSA assessment was performed on eighty MS patients and on a control group of forty-four age-matched patients. CCT in MS and control groups was calculated by analyzing the angiographic images. Lesion and brain volumes were calculated in a representative group of MS patients. Statistical correlations among CCT and disease duration, age at disease onset, lesion load, brain volumes and EDSS were considered. A significant difference between CCT in MS patients (mean = 4.9s; sd = 1.27 s and control group (mean = 2.8s; sd = 0.51 s was demonstrated. No significant statistical correlation was found between CCT and the other parameters in all MS patients. Significantly increased CCT value in MS patients suggests the presence of microvascular dysfunctions, which do not depend on clinical and MRI findings. Hemodynamic changes may not be exclusively the result of a late chronic inflammatory process.
1. Suppression of high-density artefacts in x-ray CT images using temporal digital subtraction with application to cryotherapy
Baissalov, R.; Sandison, G.A.; Rewcastle, J.C. [Department of Medical Physics, Tom Baker Cancer Center, Calgary, Canada, T2N 4N2 2 Department of Physics and Astronomy, University of Calgary, Calgary T2N 2N4 (Canada); Donnelly, B.J. [Department of Surgery, Tom Baker Cancer Center, Calgary, Canada, T2N 4N2 4 Department of Surgery, Foothills Hospital, Calgary T2N 2T7 (Canada); Saliken, J.C. [Department of Surgery, Tom Baker Cancer Center, Calgary T2N 4N2 (Canada); Department of Diagnostic Imaging, Foothills Hospital, Calgary T2N 2T7 (Canada); McKinnon, J.G. [Department of Surgery, Foothills Hospital, Calgary T2N 2T7 (Canada); Muldrew, K. [Department of Surgery, Faculty of Medicine, University of Calgary, Calgary T2N 2T7 (Canada)
2000-05-01
Image guidance in cryotherapy is usually performed using ultrasound. Although not currently in routine clinical use, x-ray CT imaging is an alternative means of guidance that can display the full 3D structure of the iceball, including frozen and unfrozen regions. However, the quality of x-ray CT images is compromised by the presence of high-density streak artefacts. To suppress these artefacts we applied temporal digital subtraction (TDS). This TDS method has the added advantage of improving the grey-scale contrast between frozen and unfrozen tissue in the CT images. Two sets of CT images were taken of a phantom material, cryoprobes and a urethral warmer (UW) before and during the cryoprobe freeze cycle. The high-density artefacts persisted in both image sets. TDS was performed on these two image sets using the corresponding mask image of unfrozen material and the same geometrical configuration of the cryoprobes and the UW. The resultant difference image had a significantly reduced artefact content. Thus TDS can be used to significantly suppress or eliminate high-density CT streak artefacts without reducing the metallic content of the cryoprobes. In vivo study needs to be conducted to establish the utility of this TDS procedure for CT assisted prostate or liver cryotherapy. Applying TDS in x-ray CT guided cryotherapy will facilitate estimation of the number and location of all frozen and unfrozen regions, potentially making cryotherapy safer and less operator dependent. (author)
2. Evaluation of changes of intracranial blood flow after carotid artery stenting using digital subtraction angiography flow assessment
2015-01-01
AIM: To evaluate the changes of intracranial blood flow after carotid artery stenting(CAS), using the flow assessment application "Flow-Insight", which was developed in our department.METHODS: Twenty patients treated by CAS participated in this study. We analyzed the change in concentration of the contrast media at the anterior-posterior and profile view image with the flow assessment application "Flow-Insight". And we compared the results with N-isopropyl-p-[123I] iodoamphetamine-single-photon emission computed tomography(IMP SPECT) performed before and after the treatment. RESULTS: From this study, 200% of the parameter "blood flow" change in the post/pre-treatment is suggested as the critical line of the hyperperfusion syndrome arise. Although the observed blood flow increase in the digital subtraction angiography system did not strongly correlate with the rate of increase of SPECT, the "Flow-Insight" reflected the rate of change of the vessels well. However, for patients with reduced reserve blood flow before CAS, a highly elevated site was in agreement with the site analysis results. CONCLUSION: We concluded that the cerebral angiography flow assessment application was able to more finely reveal hyperperfusion regions in the brain after CAS compared to SPECT.
3. Double-blind comparison of safety and efficacy of iomeprol and iopamidol in carotid digital subtraction angiography.
Beltramello, A; Piovan, E; Rosta, L
1994-05-01
Iomeprol is a nonionic monomer which provides injectable formulations with the lowest osmolalities and the lowest viscosities among the currently available low-osmolar radiographic contrast agents of the same category. These favourable physico-chemical characteristics, together with high water solubility and low molecular toxicity, make this agent particularly suitable for carotid angiography, a procedure in which contrast-induced blood-brain barrier damage is maximal. This single-centre, randomised, double-blind, parallel-group study aimed at comparing the safety, tolerance and efficacy of 200 mgI/ml solutions of iomeprol and iopamidol in 100 consenting adult inpatients undergoing carotid intra-arterial digital subtraction angiography (IA-DSA). Both agents appeared to be safe and well tolerated. Only minor and transient adverse events occurred throughout the study. Electroencephalographic and neurological examinations performed pre- and post-contrast showed no abnormality induced by the test compounds. Vessel opacification was good or excellent in the vast majority of technically adequate examinations. Information provided by the angiographic examination was useful for subsequent patient management in almost all cases. It is concluded that iomeprol-200 and iopamidol-200 are safe and effective contrast media when used for carotid IA-DSA, an examination which proves useful not only for the diagnosis of vascular lesions, but also to best direct the management of patients scheduled for surgery of intracranial tumors.
4. Cerebral circulation time is prolonged and not correlated with EDSS in multiple sclerosis patients: a study using digital subtracted angiography.
Monti, Lucia; Donati, Donatella; Menci, Elisabetta; Cioni, Samuele; Bellini, Matteo; Grazzini, Irene; Leonini, Sara; Galluzzi, Paolo; Bracco, Sandra; Severi, Sauro; Burroni, Luca; Casasco, Alfredo; Morbidelli, Lucia; Santarnecchi, Emiliano; Piu, Pietro
2015-01-01
Literature has suggested that changes in brain flow circulation occur in patients with multiple sclerosis. In this study, digital subtraction angiography (DSA) was used to measure the absolute CCT value in MS patients and to correlate its value to age at disease onset and duration, and to expand disability status scale (EDSS). DSA assessment was performed on eighty MS patients and on a control group of forty-four age-matched patients. CCT in MS and control groups was calculated by analyzing the angiographic images. Lesion and brain volumes were calculated in a representative group of MS patients. Statistical correlations among CCT and disease duration, age at disease onset, lesion load, brain volumes and EDSS were considered. A significant difference between CCT in MS patients (mean = 4.9s; sd = 1.27 s) and control group (mean = 2.8s; sd = 0.51 s) was demonstrated. No significant statistical correlation was found between CCT and the other parameters in all MS patients. Significantly increased CCT value in MS patients suggests the presence of microvascular dysfunctions, which do not depend on clinical and MRI findings. Hemodynamic changes may not be exclusively the result of a late chronic inflammatory process.
5. Whole-brain CT digital subtraction angiography of cerebral dural arteriovenous fistula using 320-detector row CT
Fujiwara, Hirokazu; Momoshima, Suketaka; Kuribayashi, Sachio [Keio University, Department of Diagnostic Radiology, School of Medicine, Tokyo (Japan); Akiyama, Takenori [Keio University, Department of Neurosurgery, School of Medicine, Tokyo (Japan)
2013-07-15
The purpose of this study was to evaluate the usefulness of CT digital subtraction angiography (CTDSA) by using 320-detector row CT in the diagnosis and classification of cerebral dural arteriovenous fistula (dAVF) and comparing it with DSA as the standard reference. A total of 29 CTDSA/DSA from 25 patients with dAVF were retrospectively evaluated by two neuroradiologists. The presence, Cognard classification, and feeding arteries of dAVFs on CTDSA were assessed according to DSA. DSA depicted 33 dAVFs in 28 cases. By consensus reading, CTDSA correctly detected 32 dAVFs in 27 cases and properly graded 31 lesions. The intermodality agreement for the presence and classification of dAVFs was excellent (kappa = 0.955 and 0.921, respectively). CTDSA detected 77 of 109 feeding arteries (70.6 %) in 25 cases. The intermodality agreement for the feeding arteries was good (kappa = 0.713). Although CTDSA is limited in temporal and spatial resolution in comparison with DSA, it is an effective non-invasive tool for the detection and classification of dAVF. (orig.)
6. Initial testing of a 3D printed perfusion phantom using digital subtraction angiography
Wood, Rachel P.; Khobragade, Parag; Ying, Leslie; Snyder, Kenneth; Wack, David; Bednarek, Daniel R.; Rudin, Stephen; Ionita, Ciprian N.
2015-03-01
Perfusion imaging is the most applied modality for the assessment of acute stroke. Parameters such as Cerebral Blood Flow (CBF), Cerebral Blood volume (CBV) and Mean Transit Time (MTT) are used to distinguish the tissue infarct core and ischemic penumbra. Due to lack of standardization these parameters vary significantly between vendors and software even when provided with the same data set. There is a critical need to standardize the systems and make them more reliable. We have designed a uniform phantom to test and verify the perfusion systems. We implemented a flow loop with different flow rates (250, 300, 350 ml/min) and injected the same amount of contrast. The images of the phantom were acquired using a Digital Angiographic system. Since this phantom is uniform, projection images obtained using DSA is sufficient for initial validation. To validate the phantom we measured the contrast concentration at three regions of interest (arterial input, venous output, perfused area) and derived time density curves (TDC). We then calculated the maximum slope, area under the TDCs and flow. The maximum slope calculations were linearly increasing with increase in flow rate, the area under the curve decreases with increase in flow rate. There was 25% error between the calculated flow and measured flow. The derived TDCs were clinically relevant and the calculated flow, maximum slope and areas under the curve were sensitive to the measured flow. We have created a systematic way to calibrate existing perfusion systems and assess their reliability.
7. Marginal Accuracy and Internal Fit of Dental Copings Fabricated by Modern Additive and Subtractive Digital Technologies.
Nelson, Neha; K S, Jyothi; Sunny, Kiran
2017-03-01
The margins of copings for crowns and retainers of fixed partial dentures affect the progress of microleakage and dental caries. Failures occur due to altered fit which is also influenced by the method of fabrication. An in-vitro study was conducted to determine among the cast base metal, copy milled zirconia, computer aided designing computer aided machining/manufacturing zirconia and direct metal laser sintered copings which showed best marginal accuracy and internal fit. Forty extracted maxillary premolars were mounted on an acrylic model and reduced occlusally using a milling machine up to a final tooth height of 4 mm from the cementoenamel junction. Axial reduction was accomplished on a surveyor and a chamfer finish line was given. The impressions and dies were made for fabrication of copings which were luted on the prepared teeth under standardized loading, embedded in self-cure acrylic resin, sectioned and observed using scanning electron microscope for internal gap and marginal accuracy. The copings fabricated using direct metal laser sintering technique exhibited best marginal accuracy and internal fit. Comparison of mean between the four groups by ANOVA and post-hoc Tukey HSD tests showed a statistically significant difference between all the groups (p⟨0.05). It was concluded that the copings fabricated using direct metal laser sintering technique exhibited best marginal accuracy and internal fit. Additive digital technologies such as direct metal laser sintering could be cost-effective for the clinician, minimize failures related to fit and increase longevity of teeth and prostheses. Copyright© 2017 Dennis Barber Ltd.
8. Diagnostic yield and accuracy of CT angiography, MR angiography, and digital subtraction angiography for detection of macrovascular causes of intracerebral haemorrhage: prospective, multicentre cohort study
van Asch, Charlotte J. J.; Birgitta K Velthuis; Rinkel, Gabriël J E; Algra, Ale; de Kort, Gerard A. P.; Witkamp, Theo D.; de Ridder, Johanna C M; van Nieuwenhuizen, Koen M.; De Leeuw, Frank Erik; Schonewille, Wouter J.; de Kort, Paul L. M.; Dippel, Diederik W; Raaymakers, Theodora W M; Hofmeijer, Jeannette; Wermer, Marieke J. H.
2015-01-01
Study question What are the diagnostic yield and accuracy of early computed tomography (CT) angiography followed by magnetic resonance imaging/angiography (MRI/MRA) and digital subtraction angiography (DSA) in patients with non-traumatic intracerebral haemorrhage? Methods This prospective diagnostic study enrolled 298 adults (18-70 years) treated in 22 hospitals in the Netherlands over six years. CT angiography was performed within seven days of haemorrhage. If the result was negative, MRI/MR...
9. Pedal angiography in peripheral arterial occlusive disease: first-pass i.v. contrast-enhanced MR angiography with blood pool contrast medium versus intraarterial digital subtraction angiography.
Kos, Sebastian; Reisinger, Clemens; Aschwanden, Markus; Bongartz, Georg M; Jacob, Augustinus L; Bilecen, Deniz
2009-03-01
The purpose of this study was to prospectively evaluate first-pass i.v. gadofosveset-enhanced MR angiography in patients with peripheral arterial occlusive disease for visualization of the pedal arteries and stenosis or occlusion of those arteries with intraarterial digital subtraction angiography as the reference standard. Twenty patients with peripheral arterial occlusive disease (nine women, 11 men; age-range 58-83 years) were prospectively enrolled. Gadofosveset first-pass contrast-enhanced MR angiography was performed with a 1.5-T system, a dedicated foot coil, and cuff compression to the calf. Arterial segments were assessed for degree of arterial stenosis, arterial visibility, diagnostic utility, and venous contamination. Detection of vessel stenosis or occlusion was evaluated in comparison with findings at digital subtraction angiography. The unpaired Student's t test was used to test arterial visibility with the two techniques. First-pass MR angiography with gadofosveset had good diagnostic utility in 83.9% of all segments and no venous contamination in 96.8% of all segments. There was no difference between the performance of intraarterial digital subtraction angiography and that of i.v. contrast-enhanced MR angiography in arterial visibility overall (p = 0.245) or in subgroup analysis of surgical arterial bypass targets (p = 0.202). The overall sensitivity, specificity, and accuracy of i.v. gadofosveset-enhanced MR angiography for characterization of clinically significant stenosis and occlusion were 91.4%, 96.1%, and 93.9%. In the subgroup analysis, the sensitivity, specificity, and accuracy were 85.5%, 96.5%, and 92.1%. Gadofosveset-enhanced MR angiography of the pedal arteries in patients with peripheral arterial occlusive disease has arterial visibility equal to that of digital subtraction angiography and facilitates depiction of clinically significant stenosis and occlusion.
10. Follow-up after embolization of ruptured intracranial aneurysms: A prospective comparison of two-dimensional digital subtraction angiography, three-dimensional digital subtraction angiography, and time-of-flight magnetic resonance angiography
Serafin, Zbigniew; Strzesniewski, Piotr; Lasek, Wladyslaw [Nicolaus Copernicus University, Collegium Medicum, Department of Radiology and Diagnostic Imaging, Bydgoszcz (Poland); Beuth, Wojciech [Nicolaus Copernicus University, Collegium Medicum, Department of Neurosurgery and Neurotraumatology, Bydgoszcz (Poland)
2012-11-15
To prospectively compare of the diagnostic value of digital subtraction angiography (DSA) and time-of-flight magnetic resonance angiography (TOF-MRA) in the follow-up of intracranial aneurysms after endovascular treatment. Seventy-two consecutive patients were examined 3 months after the embolization. The index tests included: two-dimensional DSA (2D-DSA), three-dimensional DSA (3D-DSA), and TOF-MRA. The reference test was a retrospective consensus between 2D-DSA images, 3D-DSA images, and source rotational DSA images. The evaluation included: detection of the residual flow, quantification of the flow, and validity of the decision regarding retreatment. Intraobserver agreement and interobserver agreement were determined. The sensitivity and specificity of residual flow detection ranged from 84.6 % (2D-DSA and TOF-MRA) to 92.3 % (3D-DSA) and from 91.3 % (TOF-MRA) to 97.8 % (3D-DSA), respectively. The accuracy of occlusion degree evaluation ranged from 0.78 (2D-DSA) to 0.92 (3D-DSA, Cohen's kappa). The 2D-DSA method presented lower performance in the decision on retreatment than 3D-DSA (P < 0.05, ROC analysis). The intraobserver agreement was very good for all techniques ({kappa} = 0.80-0.97). The interobserver agreement was moderate for TOF-MRA and very good for 2D-DSA and 3D-DSA ({kappa} = 0.72-0.94). Considering the invasiveness of DSA and the minor difference in the diagnostic performance between 3D-DSA and TOF-MRA, the latter method should be the first-line modality for follow-up after aneurysm embolization. (orig.)
11. An automatic fuzzy-based multi-temporal brain digital subtraction angiography image fusion algorithm using curvelet transform and content selection strategy.
Momeni, Saba; Pourghassem, Hossein
2014-08-01
Recently image fusion has prominent role in medical image processing and is useful to diagnose and treat many diseases. Digital subtraction angiography is one of the most applicable imaging to diagnose brain vascular diseases and radiosurgery of brain. This paper proposes an automatic fuzzy-based multi-temporal fusion algorithm for 2-D digital subtraction angiography images. In this algorithm, for blood vessel map extraction, the valuable frames of brain angiography video are automatically determined to form the digital subtraction angiography images based on a novel definition of vessel dispersion generated by injected contrast material. Our proposed fusion scheme contains different fusion methods for high and low frequency contents based on the coefficient characteristic of wrapping second generation of curvelet transform and a novel content selection strategy. Our proposed content selection strategy is defined based on sample correlation of the curvelet transform coefficients. In our proposed fuzzy-based fusion scheme, the selection of curvelet coefficients are optimized by applying weighted averaging and maximum selection rules for the high frequency coefficients. For low frequency coefficients, the maximum selection rule based on local energy criterion is applied to better visual perception. Our proposed fusion algorithm is evaluated on a perfect brain angiography image dataset consisting of one hundred 2-D internal carotid rotational angiography videos. The obtained results demonstrate the effectiveness and efficiency of our proposed fusion algorithm in comparison with common and basic fusion algorithms.
12. CT angiographic analysis of carotid artery stenosis: comparison of manual assessment, semiautomatic vessel analysis, and digital subtraction angiography.
Silvennoinen, H M; Ikonen, S; Soinne, L; Railo, M; Valanne, L
2007-01-01
To compare multisection CT angiography (CTA) analyzed with source/maximum intensity projection (MIP) images as well as semiautomated vessel analysis software with intra-arterial digital subtraction angiography (DSA) in detection and grading of carotid artery bifurcation stenosis. Consecutive patients with sonography evidence of a marked internal carotid artery stenosis underwent both carotid CTA and DSA (37 patients, 73 vessels). In CTA, the grade of stenosis was determined using axial source and MIP images as well as vessel analysis. The scans were blind-analyzed by 2 neuroradiologists using the NASCET criteria. Correlation of CTA source/MIP images versus DSA estimates of stenosis (R = 0.95) was higher than for the vessel analysis method versus DSA (R = 0.89). Compared with DSA, CTA source/MIP images underestimated high (78.2% versus 86.4%, P grades of stenosis (57.3% versus 63.1%, P grade stenosis, sensitivity and specificity of source/MIP image CTA were 75% and 96%, respectively, whereas for the vessel analysis method, they were 47% and 96%, respectively. For moderate stenosis, the source/MIP image CTA sensitivity and specificity were 88% and 82%, respectively, and for vessel analysis method, 62% and 82%, respectively. CTA detected all 4 occlusions. In evaluation of carotid stenosis, CTA provides an adequate, less invasive alternative with a high correlation to conventional DSA, though it tends to underestimate clinically relevant grades of stenosis. Its accuracy is not improved by semiautomated analysis. The data support the use of CTA in confirming carotid occlusion.
13. Blood Pool Contrast-enhanced Magnetic Resonance Angiography with Correlation to Digital Subtraction Angiography: A Pictorial Review
Martha-Grace Knuttinen
2014-01-01
14. Effect of injection technique on temporal parametric imaging derived from digital subtraction angiography in patient specific phantoms
Ionita, Ciprian N.; Garcia, Victor L.; Bednarek, Daniel R.; Snyder, Kenneth V.; Siddiqui, Adnan H.; Levy, Elad I.; Rudin, Stephen
2014-03-01
Parametric imaging maps (PIM's) derived from digital subtraction angiography (DSA) for the cerebral arterial flow assessment in clinical settings have been proposed, but experiments have yet to determine the reliability of such studies. For this study, we have observed the effects of different injection techniques on PIM's. A flow circuit set to physiologic conditions was created using an internal carotid artery phantom. PIM's were derived for two catheter positions, two different contrast bolus injection volumes (5ml and 10 ml), and four injection rates (5, 10, 15 and 20 ml/s). Using a gamma variate fitting approach, we derived PIM's for mean-transit-time (MTT), time-to-peak (TTP) and bolus-arrivaltime (BAT). For the same injection rates, a larger bolus resulted in an increased MTT and TTP, while a faster injection rate resulted in a shorter MTT, TTP, and BAT. In addition, the position of the catheter tip within the vasculature directly affected the PIM. The experiment showed that the PIM is strongly correlated with the injection conditions, and, therefore, they have to be interpreted with caution. PIM images must be taken from the same patient to be able to be meaningfully compared. These comparisons can include pre- and post-treatment images taken immediately before and after an interventional procedure or simultaneous arterial flow comparisons through the left and right cerebral hemispheres. Due to the strong correlation between PIM and injection conditions, this study indicates that this assessment method should be used only to compare flow changes before and after treatment within the same patient using the same injection conditions.
15. Comparison of contrast-enhanced multi-station MR angiography and digital subtraction angiography of the lower extremity arterial disease.
Burbelko, Mykhaylo; Augsten, Michael; Kalinowski, Marc O; Heverhagen, Johannes T
2013-06-01
To compare diagnostic accuracy of multi-station, high-spatial resolution contrast-enhanced MR angiography (CE-MRA) of the lower extremities with digital subtraction angiography (DSA) as the reference standard in patients with symptomatic peripheral arterial occlusive disease. Of 485 consecutive patients undergoing a run-off CE-MRA, 152 patients (86 male, 66 female; mean age, 71.6 years) with suspected peripheral arterial occlusive disease were included into our Institutional Review Board approved study. All patients underwent MRA and DSA of the lower extremities within 30 days. MRA was performed at 1.5 Tesla with a single bolus of 0.1 mmol/kg body weight of gadobutrol administered at a rate of 2.0 mL/s at three stations. Two readers evaluated the MRA images independently for stenosis grade and image quality. Sensitivity and specificity were derived. Sensitivity and specificity ranged from 73% to 93% and 64% to 89% and were highest in the thigh area. Both readers showed comparable results. Evaluation of good and better quality MRAs resulted in a considerable improvement in diagnostic accuracy. Contrast-enhanced MRA demonstrates good sensitivity and specificity in the investigation of the vasculature of the lower extremities. While a minor investigator experience dependence remains, it is standardizable and shows good inter-observer agreement. Our results confirm that the administration of Gadobutrol at a standard dose of 0.1 mmol/kg for contrast-enhanced runoff MRA is able to detect hemodynamically relevant stenoses. Use of contrast-enhanced MRA as an alternative to intra-arterial DSA in the evaluation and therapeutic planning of patients with suspected peripheral arterial occlusive disease is well justified. Copyright © 2012 Wiley Periodicals, Inc.
16. Intra-Arterial MR Perfusion Imaging of Meningiomas: Comparison to Digital Subtraction Angiography and Intravenous MR Perfusion Imaging
Martin, Alastair J.; Alexander, Matthew D.; McCoy, David B.; Cooke, Daniel L.; Lillaney, Prasheel; Moftakhar, Parham; Amans, Matthew R.; Settecase, Fabio; Nicholson, Andrew; Dowd, Christopher F.; Halbach, Van V.; Higashida, Randall T.; McDermott, Michael W.; Saloner, David; Hetts, Steven W.
2016-01-01
Background and Purpose To evaluate the ability of IA MR perfusion to characterize meningioma blood supply. Methods Studies were performed in a suite comprised of an x-ray angiography unit and 1.5T MR scanner that permitted intraprocedural patient movement between the imaging modalities. Patients underwent intra-arterial (IA) and intravenous (IV) T2* dynamic susceptibility MR perfusion immediately prior to meningioma embolization. Regional tumor arterial supply was characterized by digital subtraction angiography and classified as external carotid artery (ECA) dural, internal carotid artery (ICA) dural, or pial. MR perfusion data regions of interest (ROIs) were analyzed in regions with different vascular supply to extract peak height, full-width at half-maximum (FWHM), relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), and mean transit time (MTT). Linear mixed modeling was used to identify perfusion curve parameter differences for each ROI for IA and IV MR imaging techniques. IA vs. IV perfusion parameters were also directly compared for each ROI using linear mixed modeling. Results 18 ROIs were analyzed in 12 patients. Arterial supply was identified as ECA dural (n = 11), ICA dural (n = 4), or pial (n = 3). FWHM, rCBV, and rCBF showed statistically significant differences between ROIs for IA MR perfusion. Peak Height and FWHM showed statistically significant differences between ROIs for IV MR perfusion. RCBV and MTT were significantly lower for IA perfusion in the Dural ECA compared to IV perfusion. Relative CBF in IA MR was found to be significantly higher in the Dural ICA region and MTT significantly lower compared to IV perfusion. PMID:27802268
17. Sensor noise in direct digital imaging (the RadioVisioGraphy, Sens-a-Ray, and Visualix/Vixa systems) evaluated by subtraction radiography.
Wenzel, A
1994-01-01
The aim of this study was to evaluate sensor noise with the use of the subtraction method in radiographs captured with three direct digital intraoral systems. Ten radiographs were taken of the lower left molar region of a phantom head at each of three exposure times: 0.20 seconds, 0.46 seconds, and 0.60 seconds with the use of the RadioVisioGraphy (Trophy Radiologie, Vincennes, France), Sens-a-Ray (Regam Medical Systems, AB, Sundsvall, Sweden), and Visualix (Gendex, Philips Medical Systems, Inc., Monza, Italy) systems. Neither the x-ray tube nor the phantom were moved between exposures, and the three sensors were identically positioned. The images were stored in the tagged image file format provided by the systems in 8-bit depth and imported by a subtraction program. Subtractions were performed between identical images taken with the three systems. The standard deviation for the distribution of the shades of grey in the subtraction image histogram served as an expression for image noise. Paired t tests evaluated differences between the standard deviations of the subtraction images from the three systems. The standard deviation increased with increasing exposure time for all three systems (p < 0.00001). The standard deviation for the images performed with Visualix were 6.47, 10.34, and 11.16 at exposure times 0.20, 0.46, and 0.60, respectively. For the RadioVisioGraphy, these values were 1.61, 2.03, and 2.18, and for Sens-a-Ray 2.90, 3.98, and 3.96, respectively. The differences between the systems were highly statistically significant (p < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)
18. Comparison of C-arm Computed Tomography and Digital Subtraction Angiography in Patients with Chronic Thromboembolic Pulmonary Hypertension
Hinrichs, Jan B., E-mail: [email protected]; Marquardt, Steffen, E-mail: [email protected]; Falck, Christian von, E-mail: [email protected] [Hannover Medical School, Department for Diagnostic and Interventional Radiology, German Center for Lung Research (DZL) (Germany); Hoeper, Marius M., E-mail: [email protected]; Olsson, Karen M., E-mail: [email protected] [Hannover Medical School, Clinic for Pneumology, German Center for Lung Research (DZL) (Germany); Wacker, Frank K., E-mail: [email protected]; Meyer, Bernhard C., E-mail: [email protected] [Hannover Medical School, Department for Diagnostic and Interventional Radiology, German Center for Lung Research (DZL) (Germany)
2016-01-15
PurposeTo assess the feasibility and diagnostic performance of contrast-enhanced, C-arm computed tomography (CACT) of the pulmonary arteries compared to digital subtraction angiography (DSA) in patients suffering from chronic thromboembolic pulmonary hypertension (CTEPH).MaterialsFifty-two patients with CTEPH underwent ECG-gated DSA and contrast-enhanced CACT. Two readers (R1, R2) independently evaluated pulmonary artery segments and their sub-segmental branching using DSA and CACT for optimal image quality. Afterwards, the diagnostic findings, i.e., intraluminal filling defects, stenosis, and occlusion, were compared. Inter-modality and inter-observer agreement was calculated, and subsequently consensus reading was done and correlated to a reference standard representing the overall consensus of both modalities. Fisher’s exact test and Cohen’s Kappa were applied.ResultsA total of 1352 pulmonary segments were evaluated, of which 1255 (92.8 %) on DSA and 1256 (92.9 %) on CACT were rated to be fully diagnostic. The main causes of the non-diagnostic image quality were motion artifacts on CACT (R1:37, R2:78) and insufficient contrast enhancement on DSA (R1:59, R2:38). Inter-observer agreement was good for DSA (κ = 0.74) and CACT (κ = 0.75), while inter-modality agreement was moderate (R1: κ = 0.46, R2: κ = 0.47). Compared to the reference standard, the inter-modality agreement for CACT was excellent (κ = 0.96), whereas it was inferior for DSA (κ = 0.61) due to the higher number of abnormal consensus findings read as normal on DSA.ConclusionCACT of the pulmonary arteries is feasible and provides additional information to DSA. CACT has the potential to improve the diagnostic work-up of patients with CTEPH and may be particularly useful prior to surgical or interventional treatment.
19. Inter- and intra-rater agreement in the assessment of the vascularity of spinal metastases using digital subtraction angiography tumor blush
Clausen, Caroline; Dahl, Benny; Christiansen Frevert, Susanne;
2016-01-01
Background: Preoperative embolization is based on the preoperative digital subtraction angiography (DSA) tumor blush, and as such is considered the “gold standard” for determining tumor vascularity. However, to our knowledge reliability studies evaluating vascularity ratings of DSA tumor blush...... in spinal metastases have not been published previously. Purpose: To evaluate inter- and intra-rater agreement in the assessment of the vascularity of spinal metastases using DSA tumor blush. Material and Methods: This reliability study included 46 patients with symptomatic metastatic spinal cord...
20. Identification of Students' Intuitive Mental Computational Strategies for 1, 2 and 3 Digits Addition and Subtraction: Pedagogical and Curricular Implications
Ghazali, Munirah; Alias, Rohana; Ariffin, Noor Asrul Anuar; Ayub, Ayminsyadora
2010-01-01
This paper reports on a study to examine mental computation strategies used by Year 1, Year 2, and Year 3 students to solve addition and subtraction problems. The participants in this study were twenty five 7 to 9 year-old students identified as excellent, good and satisfactory in their mathematics performance from a school in Penang, Malaysia.…
1. Identification of Students' Intuitive Mental Computational Strategies for 1, 2 and 3 Digits Addition and Subtraction: Pedagogical and Curricular Implications
Ghazali, Munirah; Alias, Rohana; Ariffin, Noor Asrul Anuar; Ayub, Ayminsyadora
2010-01-01
This paper reports on a study to examine mental computation strategies used by Year 1, Year 2, and Year 3 students to solve addition and subtraction problems. The participants in this study were twenty five 7 to 9 year-old students identified as excellent, good and satisfactory in their mathematics performance from a school in Penang, Malaysia.…
2. Gradient-based 3D-2D registration of cerebral angiograms
Mitrović, Uroš; Markelj, Primož; Likar, Boštjan; Miloševič, Zoran; Pernuš, Franjo
2011-03-01
Endovascular treatment of cerebral aneurysms and arteriovenous malformations (AVM) involves navigation of a catheter through the femoral artery and vascular system into the brain and into the aneurysm or AVM. Intra-interventional navigation utilizes digital subtraction angiography (DSA) to visualize vascular structures and X-ray fluoroscopy to localize the endovascular components. Due to the two-dimensional (2D) nature of the intra-interventional images, navigation through a complex three-dimensional (3D) structure is a demanding task. Registration of pre-interventional MRA, CTA, or 3D-DSA images and intra-interventional 2D DSA images can greatly enhance visualization and navigation. As a consequence of better navigation in 3D, the amount of required contrast medium and absorbed dose could be significantly reduced. In the past, development and evaluation of 3D-2D registration methods received considerable attention. Several validation image databases and evaluation criteria were created and made publicly available in the past. However, applications of 3D-2D registration methods to cerebral angiograms and their validation are rather scarce. In this paper, the 3D-2D robust gradient reconstruction-based (RGRB) registration algorithm is applied to CTA and DSA images and analyzed. For the evaluation purposes five image datasets, each comprised of a 3D CTA and several 2D DSA-like digitally reconstructed radiographs (DRRs) generated from the CTA, with accurate gold standard registrations were created. A total of 4000 registrations on these five datasets resulted in mean mTRE values between 0.07 and 0.59 mm, capture ranges between 6 and 11 mm and success rates between 61 and 88% using a failure threshold of 2 mm.
3. A comparison between magnetic resonance angiography at 3 teslas (time-of-flight and contrast-enhanced and flat-panel digital subtraction angiography in the assessment of embolized brain aneurysms
Guilherme S. Nakiri
2011-01-01
Full Text Available PURPOSE: To compare the time-of-flight and contrast-enhanced- magnetic resonance angiography techniques in a 3 Tesla magnetic resonance unit with digital subtraction angiography with the latest flat-panel technology and 3D reconstruction in the evaluation of embolized cerebral aneurysms. INTRODUCTION: Many embolized aneurysms are subject to a recurrence of intra-aneurismal filling. Traditionally, imaging surveillance of coiled aneurysms has consisted of repeated digital subtraction angiography. However, this method has a small but significant risk of neurological complications, and many authors have advocated the use of noninvasive imaging methods for the surveillance of embolized aneurysms. METHODS: Forty-three aneurysms in 30 patients were studied consecutively between November 2009 and May 2010. Two interventional neuroradiologists rated the time-of-flight-magnetic resonance angiography, the contrast-enhanced-magnetic resonance angiography, and finally the digital subtraction angiography, first independently and then in consensus. The status of aneurysm occlusion was assessed according to the Raymond scale, which indicates the level of recanalization according to degrees: Class 1: excluded aneurysm; Class 2: persistence of a residual neck; Class 3: persistence of a residual aneurysm. The agreement among the analyses was assessed by applying the Kappa statistic. RESULTS: Inter-observer agreement was excellent for both methods (K = 0.93; 95 % CI: 0.84-1. Inter-technical agreement was almost perfect between time-of-flight-magnetic resonance angiography and digital subtraction angiography (K = 0.98; 95 % CI: 0.93-1 and between time-of-flight-magnetic resonance angiography and contrast-enhanced-magnetic resonance angiography (K = 0.98; 95% CI: 0.93-1. Disagreement occurred in only one case (2.3%, which was classified as Class I by time-of-flight-magnetic resonance angiography and Class II by digital subtraction angiography. The agreement between
4. Subtracted geometry
Saleem, Zain Hamid
In this thesis we study a special class of black hole geometries called subtracted geometries. Subtracted geometry black holes are obtained when one omits certain terms from the warp factor of the metric of general charged rotating black holes. The omission of these terms allows one to write the wave equation of the black hole in a completely separable way and one can explicitly see that the wave equation of a massless scalar field in this slightly altered background of a general multi-charged rotating black hole acquires an SL(2, R) x SL(2, R) x SO(3) symmetry. The "subtracted limit" is considered an appropriate limit for studying the internal structure of the non-subtracted black holes because new 'subtracted' black holes have the same horizon area and periodicity of the angular and time coordinates in the near horizon regions as the original black hole geometry it was constructed from. The new geometry is asymptotically conical and is physically similar to that of a black hole in an asymptotically confining box. We use the different nice properties of these geometries to understand various classically and quantum mechanically important features of general charged rotating black holes.
5. A new method for analyzing auditory brain-stem response waveforms using a moving-minimum subtraction procedure of digitized analog recordings
Källstr
2014-06-01
Full Text Available Johan Källstrand,1 Tommy Lewander,2 Eva Baghdassarian,2,3 Sören Nielzén4 1SensoDetect AB, Lund, 2Department of Neuroscience, Medical Faculty, Uppsala University, 3Department of Psychiatry, Uppsala University Hospital, Uppsala, 4Department of Psychiatry, Medical Faculty, University of Lund, Lund, Sweden Abstract: The auditory brain-stem response (ABR waveform comprises a set of waves (labeled I–VII recorded with scalp electrodes over 10 ms after an auditory stimulation with a brief click sound. Quite often, the waves are fused (confluent and baseline-irregular and sloped, making wave latencies and wave amplitudes difficult to establish. In the present paper, we describe a method, labeled moving-minimum subtraction, based on digitization of the analog ABR waveform (154 data points/ms in order to achieve alignment of the ABR response to a straight baseline, often with clear baseline separation of waves and resolution of fused waves. Application of the new method to groups of patients showed marked differences in ABR waveforms between patients with schizophrenia versus patients with adult attention deficit/hyperactivity disorder versus healthy controls. The findings show promise regarding the possibility to identify ABR markers to be used as biomarkers as support for clinical diagnoses of these and other neuropsychiatric disorders. Keywords: auditory brain-stem response, digitization, moving-minimum subtraction method, baseline alignment, schizophrenia, ADHD
6. Using digital subtraction in computer simulated images as a tool to aid the visual detection of masked lesions in dense breasts
Schiabel, Homero; Guimarães, Luciana T.; Sousa, Maria A. Z.
2015-03-01
This work proposes a simulation model involving subtraction of digital mammography images obtained at different X-ray beam levels of energy to aid the detection of breast malignant lesions. Absorption coefficients behavior of 3 main structures of clinical interest - adipose tissue, fiber glandular tissue and the typical carcinoma - as a function of the beam energy from a Mo X-ray tube was the basis to develop a computer simulation of the possible acquired images. The simulation has considered a typical compressed breast with 4.5cm in thickness, and variations of the carcinoma and glandular tissues thicknesses - 0.4 up to 2.0cm and 4.1 to 2.5cm, respectively - were evaluated as a function of the photons mean energy - 14 up to 25 keV, in the typical mammography energy range. Results have shown that: (a) if the carcinoma thickness is over 0.4cm, its detection may be feasible even masked by fiber tissue with exposures in the range of 19 to 25 keV; (b) for masked carcinoma with thickness in the range of 0.4-2.0cm, the proposed procedure can enhance it in the image resulting from the digital subtraction between images obtained at 14 and at 22 keV. Therefore such results indicate that this simulation procedure can be a useful tool in aiding the identification of possible missed malignant lesions which could not be detected in the typical exam, mainly considering dense breasts.
7. Dynamic Contrast-Enhanced MR Angiography Exploiting Subspace Projection for Robust Angiogram Separation.
Park, Suhyung; Kim, Eung Yeop; Sohn, Chul-Ho; Park, Jaeseok
2017-02-01
Dynamic contrast-enhanced magnetic resonance angiography (DCE MRA) has been widely used as a clinical routine for diagnostic assessment of vascular morphology and hemodynamics. It requires high spatial and temporal resolution to capture rapid variation of DCE signals within a limited imaging time. Subtraction-based approaches are typically employed to selectively delineate arteries while eliminating unwanted background signals. Nevertheless, in the presence of subject motion with time, conventional subtraction approaches suffer from incomplete background suppression that impairs the detectability of arteries. In this work, we propose a novel, DCE MRA method that exploits subspace projection (SP) based angiogram separation for robust background suppression. A new, SP-based DCE signal model is introduced, in which images are decomposed into stationary background tissues, motion-induced artifacts, and DCE angiograms of interest. Constrained image reconstruction with sparsity priors is performed to project motion-induced artifacts onto the predefined subspace while extracting DCE angiograms of interest. Simulations and experimental studies validate that the proposed method outperforms existing techniques with increasing reduction factors in suppressing artifacts and noise.
8. Local connected fractal dimensions and lacunarity analyses of 60 degrees fluorescein angiograms.
Landini, G; Murray, P I; Misson, G P
1995-12-01
The retinal vascular tree exhibits fractal characteristics. These findings relate to the mechanisms involved in the vascularization process and to the objective morphologic characterization of retinal vessels using fractal analysis. Although normal retinas show uniform patterns of blood vessels, in pathologic retinas with central vein or artery occlusions, the patterns are irregular. Because the generalized box fractal dimension fails to differentiate successfully between normal and abnormal retinal vessels in 60 degrees fluorescein angiograms, the authors have further investigated this problem using the local connected fractal dimension (alpha). The authors studied 24 digitized 60 degrees fluorescein angiograms of patients with normal retinas and 5 angiograms of patients with central retinal vein or artery occlusion. The pointwise method estimated the local complexity of the angiogram within a finite window centered on those pixels that belong to the retinal vessels. Color-coded dimensional images of the angiograms were constructed by plotting the pixels forming the object with a color that corresponded to specific values of alpha +/- delta alpha. The color-coded representation allowed recognition of areas with increased or decreased local angiogram complexity. The alpha distributions showed differences between normal and pathologic retinas, which overcomes problems encountered when using the methods of calculating the generalized fractal dimensions. A multivariate linear discriminant function using parameters from the alpha distribution and a further fractal parameter--lacunarity--reclassified 23 of the 24 normal and 4 of the 5 pathologic angiograms in their original groups (total: 92.1% correct). This methodology may be used for automatic detection and objective characterization of local retinal vessel abnormalities.
9. Image subtraction by solid state electroradiography
1984-06-01
An analog radiographic image subtraction technique is presented. A selenium photoconductor is used as the radiation sensitive medium and image subtraction is achieved by electrostatically adding latent images of opposite polarities to get a latent image of the region of interest. In principle, the technique is simple and a comparison with commercial digital techniques shows a similar image quality, suggesting that the electrostatic subtraction technique could be developed into a clinical tool as an inexpensive alternative to digital radiography.
10. A novel approach to background subtraction in contrast-enhanced dual-energy digital mammography with commercially available mammography devices: Polychromaticity correction.
Contillo, Adriano; Di Domenico, Giovanni; Cardarelli, Paolo; Gambaccini, Mauro; Taibi, Angelo
2015-11-01
Contrast-enhanced digital mammography is an image subtraction technique that is able to improve the detectability of lesions in dense breasts. One of the main sources of error, when the technique is performed by means of commercial mammography devices, is represented by the intrinsic polychromaticity of the x-ray beams. The aim of the work is to propose an iterative procedure, which only assumes the knowledge of a small set of universal quantities, to take into account the polychromaticity and correct the subtraction results accordingly. In order to verify the procedure, it has been applied to an analytical simulation of a target containing a contrast medium and to actual radiographs of a breast phantom containing cavities filled with a solution of the same medium. The reconstructed densities of contrast medium were compared, showing very good agreement between the theoretical predictions and the experimental results already after the first iteration. Furthermore, the convergence of the iterative procedure was studied, showing that only a small number of iterations is necessary to reach limiting values. The proposed procedure represents an efficient solution to the polychromaticity issue, qualifying therefore as a viable alternative to inverse-map functions.
11. A novel approach to background subtraction in contrast-enhanced dual-energy digital mammography with commercially available mammography devices: Polychromaticity correction
Contillo, Adriano, E-mail: [email protected]; Di Domenico, Giovanni; Cardarelli, Paolo; Gambaccini, Mauro; Taibi, Angelo [Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara, Via Saragat 1, Ferrara I-44122 (Italy)
2015-11-15
Purpose: Contrast-enhanced digital mammography is an image subtraction technique that is able to improve the detectability of lesions in dense breasts. One of the main sources of error, when the technique is performed by means of commercial mammography devices, is represented by the intrinsic polychromaticity of the x-ray beams. The aim of the work is to propose an iterative procedure, which only assumes the knowledge of a small set of universal quantities, to take into account the polychromaticity and correct the subtraction results accordingly. Methods: In order to verify the procedure, it has been applied to an analytical simulation of a target containing a contrast medium and to actual radiographs of a breast phantom containing cavities filled with a solution of the same medium. Results: The reconstructed densities of contrast medium were compared, showing very good agreement between the theoretical predictions and the experimental results already after the first iteration. Furthermore, the convergence of the iterative procedure was studied, showing that only a small number of iterations is necessary to reach limiting values. Conclusions: The proposed procedure represents an efficient solution to the polychromaticity issue, qualifying therefore as a viable alternative to inverse-map functions.
12. Behavior Subtraction
2009-01-01
Background subtraction has been a driving engine for many computer vision and video analytics tasks. Although its many variants exist, they all share the underlying assumption that photometric scene properties are either static or exhibit temporal stationarity. While this works in some applications, the model fails when one is interested in discovering {\\it changes in scene dynamics} rather than those in a static background; detection of unusual pedestrian and motor traffic patterns is but one example. We propose a new model and computational framework that address this failure by considering stationary scene dynamics as a background'' with which observed scene dynamics are compared. Central to our approach is the concept of an {\\it event}, that we define as short-term scene dynamics captured over a time window at a specific spatial location in the camera field of view. We compute events by time-aggregating motion labels, obtained by background subtraction, as well as object descriptors (e.g., object size)....
13. 3D-2D registration of cerebral angiograms based on vessel directions and intensity gradients
Mitrovic, Uroš; Špiclin, Žiga; Štern, Darko; Markelj, Primož; Likar, Boštjan; Miloševic, Zoran; Pernuš, Franjo
2012-02-01
Endovascular treatment of cerebral aneurysms and arteriovenous malformations (AVM) involves navigation of a catheter through the femoral artery and vascular system to the site of pathology. Intra-interventional navigation is done under the guidance of one or at most two two-dimensional (2D) X-ray fluoroscopic images or 2D digital subtracted angiograms (DSA). Due to the projective nature of 2D images, the interventionist needs to mentally reconstruct the position of the catheter in respect to the three-dimensional (3D) patient vasculature, which is not a trivial task. By 3D-2D registration of pre-interventional 3D images like CTA, MRA or 3D-DSA and intra-interventional 2D images, intra-interventional tools such as catheters can be visualized on the 3D model of patient vasculature, allowing easier and faster navigation. Such a navigation may consequently lead to the reduction of total ionizing dose and delivered contrast medium. In the past, development and evaluation of 3D-2D registration methods for endovascular treatments received considerable attention. The main drawback of these methods is that they have to be initialized rather close to the correct position as they mostly have a rather small capture range. In this paper, a novel registration method that has a higher capture range and success rate is proposed. The proposed method and a state-of-the-art method were tested and evaluated on synthetic and clinical 3D-2D image-pairs. The results on both databases indicate that although the proposed method was slightly less accurate, it significantly outperformed the state-of-the-art 3D-2D registration method in terms of robustness measured by capture range and success rate.
14. Nonenhanced peripheral MR-angiography (MRA) at 3 Tesla: evaluation of quiescent-interval single-shot MRA in patients undergoing digital subtraction angiography.
Wagner, Moritz; Knobloch, Gesine; Gielen, Martin; Lauff, Marie-Teres; Romano, Valentina; Hamm, Bernd; Kröncke, Thomas
2015-04-01
Quiescent-interval single-shot MRA (QISS-MRA) is a promising nonenhanced imaging technique for assessment of peripheral arterial disease (PAD). Previous studies at 3 Tesla included only very limited numbers of patients for correlation of QISS-MRA with digital subtraction angiography (DSA) as standard of reference (SOR). The aim of this prospective institutional review board-approved study was to compare QISS-MRA at 3 Tesla with DSA in a larger patient group. Our study included 32 consecutive patients who underwent QISS-MRA, contrast-enhanced MRA (CE-MRA), and DSA. Two readers independently performed a per-segment evaluation of QISS-MRA and CE-MRA for image quality and identification of non-significant stenosis (Tesla showed similar diagnostic accuracy in the assessment of PAD. A limitation of QISS-MRA was the lower rate of assessable vessel segments compared to CE-MRA.
15. Spectrum of results of arterial digital subtraction angiography in patients after renal transplantation. Befundspektrum der arteriellen digitalen Subtraktionsangiographie bei Patienten nach Nierentransplantation
Gruetzner, G. (Heinrich-Heine-Univ., Duesseldorf (Germany). Inst. fuer Diagnostische Radiologie); Bach, D. (Medizinische Klinik und Poliklinik, Duesseldorf (Germany). Abteilung fuer Nephrologie); Fluer, P. (Heinrich-Heine-Univ., Duesseldorf (Germany). Inst. fuer Diagnostische Radiologie); Kniemeyer, H.W. (Chirurgische Klinik und Poliklinik, Duesseldorf (Germany). Abteilung fuer Gefaesschirurgie und Nierentransplantation); Moedder, U. (Heinrich-Heine-Univ., Duesseldorf (Germany). Inst. fuer Diagnostische Radiologie)
1994-06-01
Digital subtraction angiography (DSA) was performed in 53 of 417 patients with renal transplants. The incidence of clinical apparent vascular complications was 9.1% of all patients with renal transplants (38/417). The most frequent vascular disorders were formed by arterial stenoses at 5.0% of the cases followed by arterial obstructions in 1.7% of the patients. Rare vascular complications were arteriovenous fistulas (0.7%), aneurysms (0.5%) and venous thrombose (0.2%). Because of the high diagnostic value of intraarterial DSA, all patients with renal transplants with a complicated postoperative course should be eligible for angiographic control. In case of a suspected vascular disorder intraarterial DSA should be performed at an early stage. (orig.)
16. Measurement of cerebral circulation times by means of the analysis of the time-density curve using digital subtraction angiography
Tazawa, Toshiaki; Karasawa, Jun; Touho, Hajime; Kobayashi, Keisuke; Nakagawara, Jyoji; Nakauchi, Mikio; Kuriyama, Yoshihiro
1987-04-01
Five patients who had suffered a transient ischemic attack (TIA) with a normal angiogram were selected as a control group for the study of the internal-carotid-artery system, while 2 patients were selected as the controls in the study of the vertebral-artery system in order to evaluate the effect of cerebrovascular lesions. The cerebral circulation time of the internal carotid artery system was defined as the difference in the arrival times of the intraarterial contrast bolus between Fischer's C1 portion and the middle of the transverse sinus, while that of the vertebral artery system was defined as the difference in arraival times between Krayenbuhl's third or fourth segment and the middle of the transverse sinus. In the internal-carotid-artery system, the circulation time (as the time difference between the two points for the control) was 4.76 +- 0.28 (mean +- SD) sec. in TTP and 4.66 +- 0.11 sec. in MTT. In the vertebral-artery system, it was 3.97 sec. on the average in TTP and 4.16 sec. in MTT. Eleven patients with middle cerebral artery stenosis or occlusion and one patient with ''MoyaMoya'' disease were selected for a study of the ischemic lesions, while one patient with an arteriovenous malformation (AVM) was selected for a study of the effect of an arteriovenous shunt. In the symptomatic patients with middle-cerebral-artery occlusion or stenosis, the circulation time was slower than that of the control group both in TTP and in MTT. There was a significant correlation between the values of the circulation time in TTP and that in MTT. The circulation time of the patient with ''MoyaMoya'' disease was significantly slower than that of the control. In the patient with an AVM, the circulation time was much faster than in the control in TTP, while it was normal in MTT. (J.P.N.).
17. Behavior subtraction.
Jodoin, Pierre-Marc; Saligrama, Venkatesh; Konrad, Janusz
2012-09-01
Background subtraction has been a driving engine for many computer vision and video analytics tasks. Although its many variants exist, they all share the underlying assumption that photometric scene properties are either static or exhibit temporal stationarity. While this works in many applications, the model fails when one is interested in discovering changes in scene dynamics instead of changes in scene's photometric properties; the detection of unusual pedestrian or motor traffic patterns are but two examples. We propose a new model and computational framework that assume the dynamics of a scene, not its photometry, to be stationary, i.e., a dynamic background serves as the reference for the dynamics of an observed scene. Central to our approach is the concept of an event, which we define as short-term scene dynamics captured over a time window at a specific spatial location in the camera field of view. Unlike in our earlier work, we compute events by time-aggregating vector object descriptors that can combine multiple features, such as object size, direction of movement, speed, etc. We characterize events probabilistically, but use low-memory, low-complexity surrogates in a practical implementation. Using these surrogates amounts to behavior subtraction, a new algorithm for effective and efficient temporal anomaly detection and localization. Behavior subtraction is resilient to spurious background motion, such as due to camera jitter, and is content-blind, i.e., it works equally well on humans, cars, animals, and other objects in both uncluttered and highly cluttered scenes. Clearly, treating video as a collection of events rather than colored pixels opens new possibilities for video analytics.
18. Contexts for Column Addition and Subtraction
Lopez Fernandez, Jorge M.; Velazquez Estrella, Aileen
2011-01-01
In this article, the authors discuss their approach to column addition and subtraction algorithms. Adapting an original idea of Paul Cobb and Erna Yackel's from "A Contextual Investigation of Three-Digit Addition and Subtraction" related to packing and unpacking candy in a candy factory, the authors provided an analogous context by…
19. Contexts for Column Addition and Subtraction
Lopez Fernandez, Jorge M.; Velazquez Estrella, Aileen
2011-01-01
In this article, the authors discuss their approach to column addition and subtraction algorithms. Adapting an original idea of Paul Cobb and Erna Yackel's from "A Contextual Investigation of Three-Digit Addition and Subtraction" related to packing and unpacking candy in a candy factory, the authors provided an analogous context by…
20. NOTE: Suppression of high-density artefacts in x-ray CT images using temporal digital subtraction with application to cryotherapy
Baissalov, R.; Sandison, G. A.; Donnelly, B. J.; Saliken, J. C.; McKinnon, J. G.; Muldrew, K.; Rewcastle, J. C.
2000-05-01
Image guidance in cryotherapy is usually performed using ultrasound. Although not currently in routine clinical use, x-ray CT imaging is an alternative means of guidance that can display the full 3D structure of the iceball, including frozen and unfrozen regions. However, the quality of x-ray CT images is compromised by the presence of high-density streak artefacts. To suppress these artefacts we applied temporal digital subtraction (TDS). This TDS method has the added advantage of improving the grey-scale contrast between frozen and unfrozen tissue in the CT images. Two sets of CT images were taken of a phantom material, cryoprobes and a urethral warmer (UW) before and during the cryoprobe freeze cycle. The high-density artefacts persisted in both image sets. TDS was performed on these two image sets using the corresponding mask image of unfrozen material and the same geometrical configuration of the cryoprobes and the UW. The resultant difference image had a significantly reduced artefact content. Thus TDS can be used to significantly suppress or eliminate high-density CT streak artefacts without reducing the metallic content of the cryoprobes. In vivo study needs to be conducted to establish the utility of this TDS procedure for CT assisted prostate or liver cryotherapy. Applying TDS in x-ray CT guided cryotherapy will facilitate estimation of the number and location of all frozen and unfrozen regions, potentially making cryotherapy safer and less operator dependent.
1. The value of magnetic resonance imaging for the detection of the bleeding source in non-traumatic intracerebral haemorrhages: a comparison with conventional digital subtraction angiography
Lummel, Nina; Lutz, Juergen; Brueckmann, Hartmut; Linn, Jennifer [University of Munich, Department of Neuroradiology, Munich (Germany)
2012-07-15
Conventional digital subtraction angiography (DSA) is currently regarded as the gold standard in detecting underlying vascular pathologies in patients with intracerebral haemorrhages (ICH). However, the use of magnetic resonance imaging (MRI) in the diagnostic workup of ICHs has considerably increased in recent years. Our aim was to evaluate the diagnostic accuracy and yield of MRI for the detection of the underlying aetiology in ICH patients. Sixty-seven consecutive patients with an acute ICH who underwent MRI (including magnetic resonance angiography (MRA) and DSA during their diagnostic workup) were included in the study. Magnetic resonance images were retrospectively analysed by two independent neuroradiologists to determine the localisation and cause of the ICH. DSA was used as a reference standard. In seven patients (10.4%), a DSA-positive vascular aetiology was present (one aneurysm, four arteriovenous malformations, one dural arteriovenous fistula and one vasculitis). All of these cases were correctly diagnosed by both readers on MRI. In addition, MRI revealed the following probable bleeding causes in 39 of the 60 DSA-negative patients: cerebral amyloid angiopathy (17), cavernoma (9), arterial hypertension (8), haemorrhagic transformation of an ischaemic infarction (3) and malignant brain tumour with secondary ICH (2). Performing MRI with MRA proved to be an accurate diagnostic tool in detecting vascular malformations in patients with ICH. In addition, MRI provided valuable information regarding DSA-negative ICH causes, and thus had a high diagnostic yield in ICH patients. (orig.)
2. Dual-energy direct bone removal CT angiography for evaluation of intracranial aneurysm or stenosis: comparison with conventional digital subtraction angiography
Watanabe, Yoshiyuki [National Cardiovascular Center, Department of Radiology, Osaka (Japan); St. Luke' s International Hospital, Department of Radiology, Tokyo (Japan); Uotani, Kensuke; Nakazawa, Tetsuro; Higashi, Masahiro; Yamada, Naoaki; Hori, Yoshiro; Kanzaki, Suzu; Fukuda, Tetsuya; Naito, Hiroaki [National Cardiovascular Center, Department of Radiology, Osaka (Japan); Itoh, Toshihide [Siemens Asahi Medical Technologies, Tokyo (Japan)
2009-04-15
Dual-energy CT can be applied for bone elimination in cerebral CT angiography (CTA). The aim of this study was to compare the results of dual-energy direct bone removal CTA (DE-BR-CTA) with those of digital subtraction angiography (DSA). Twelve patients with intracranial aneurysms and/or ICA stenosis underwent a dual-source CT in dual-energy mode. Post-processing software selectively removed bone structures using the two energy data sets. Three-dimensional images with and without bone removal were reviewed and compared to DSA. Dual-energy bone removal was successful in all patients. For 10 patients, bone removal was good and CTA maximum-intensity projection (MIP) images could be used for vessel evaluation. For two patients, bone removal was moderate with some bone remnants, but this did not inhibit the three-dimensional visualization. Three aneurysms adjacent to the skull base were only partially visible in conventional CTA but were fully visible in DE-BR-CTA. In five patients with ICA stenosis, DE-BR-CTA revealed the stenotic lesions on the MIP images. The correlation between DSA and DE-BR-CTA was good (R {sup 2}=0.822), but DE-BR-CTA led to an overestimation of stenosis. DE-BR-CTA was able to eliminate bone structure using only a single CT data acquisition and is useful to evaluate intracranial aneurysms and stenosis. (orig.)
3. Non-contrast-enhanced MR angiography in the diagnosis of Budd-Chiari syndrome (BCS) compared with digital subtraction angiography (DSA): Preliminary results.
Yang, Chun; Li, Ceng; Zeng, Mengsu; Lu, Xin; Li, Jingjing; Wang, Jiali; Sami, Muhammad Umair; Xu, Kai
2017-02-01
Non-CE MRA techniques (true steady-state free-precession, SSFP) have been used effectively for the selective visualization of the portal venous system and inferior vena cava. Budd-Chiari Syndrome (BCS) encompasses a number of conditions that cause the obstruction of the hepatic outflow tract from the small hepatic veins to the junction of the inferior vena cava (IVC) and right atrium. The purpose of this study was to diagnose BCS with IVC obstruction using respiratory triggered three-dimensional (3D) true SSFP with T-SLIP and compare to digital subtraction angiography (DSA). The image acquisition of 3D true SSFP scans was successfully performed in 108 patients (≧2 score). The mean and SDs of the relative SNR and CNR were 55.96±2.32 and 30.72±1.56, respectively. Intergroup agreement for the detection of the 4 types (membranous obstruction, segmental occlusion, and membranous obstruction with a hole and segmental stenosis) of BCS with IVC obstruction was excellent between the Time-SLIP and the DSA. In conclusion, Time-SLIP for the detection of IVC obstruction BCS does not require the use of contrast. This procedure can achieve a high success rate, high accuracy rate and fine image quality for the diagnosis of IVC obstruction BCS. Copyright © 2016 Elsevier Inc. All rights reserved.
4. Usefulness of magnetic resonance imaging (MRI) in the detection of the lesions of gestational trophoblastic disease; Comparison with computed tomography and digital subtraction angiography
Takeuchi, Satoshi; Akahori, Taiichiro; Mochizuki, Matsuto; Kono, Michio (Kobe Univ. (Japan). School of Medicine)
1992-02-01
Twenty patients with gestational trophoblastic disease (GTN) were examined by magnetic resonance imaging (MRI), computed tomography (CT) and digital subtraction angiography (DSA), to evaluate their usefulness in the diagnosis of the disease. The lesions of hydatidiform mole were mainly composed of molar vesicles, dilated vessels and hemorrhage which were depicted as small round high intensity lesions on the T2-weighted images and as tree-like low intensity lesions and high or low intensity lesions of various shapes in the T1-, T2-weighted images. These MRI findings closely corresponded to the histopathological findings. On the other hand, CT findings obtained with hydatidiform mole were characterized by filling defects or a small round low density area on contrast enhanced images. The detection ratio for intramural lesions of invasive mole and choriocarcinoma by MRI was 83% (5/6), while that by CT was 50% (3/6). The obliteration of the junctional zone and interruption of the myometrium observed in MRI were significant signs suggesting intramural invasion of the disease. In fact, these signs in MRI were observed in all of the six cases of invasive mole or choriocarcinoma examined. In conclusion, MRI is a powerful means for the determining the intramural invasive mole and choriocarcinoma. Thus more accurate diagnosis of GTN will be obtained with the combined use of MRI and DSA. (author).
5. Flow modification in canine intracranial aneurysm model by an asymmetric stent: studies using digital subtraction angiography (DSA) and image-based computational fluid dynamics (CFD) analyses
Hoi, Yiemeng; Ionita, Ciprian N.; Tranquebar, Rekha V.; Hoffmann, Kenneth R.; Woodward, Scott H.; Taulbee, Dale B.; Meng, Hui; Rudin, Stephen
2006-03-01
An asymmetric stent with low porosity patch across the intracranial aneurysm neck and high porosity elsewhere is designed to modify the flow to result in thrombogenesis and occlusion of the aneurysm and yet to reduce the possibility of also occluding adjacent perforator vessels. The purposes of this study are to evaluate the flow field induced by an asymmetric stent using both numerical and digital subtraction angiography (DSA) methods and to quantify the flow dynamics of an asymmetric stent in an in vivo aneurysm model. We created a vein-pouch aneurysm model on the canine carotid artery. An asymmetric stent was implanted at the aneurysm, with 25% porosity across the aneurysm neck and 80% porosity elsewhere. The aneurysm geometry, before and after stent implantation, was acquired using cone beam CT and reconstructed for computational fluid dynamics (CFD) analysis. Both steady-state and pulsatile flow conditions using the measured waveforms from the aneurysm model were studied. To reduce computational costs, we modeled the asymmetric stent effect by specifying a pressure drop over the layer across the aneurysm orifice where the low porosity patch was located. From the CFD results, we found the asymmetric stent reduced the inflow into the aneurysm by 51%, and appeared to create a stasis-like environment which favors thrombus formation. The DSA sequences also showed substantial flow reduction into the aneurysm. Asymmetric stents may be a viable image guided intervention for treating intracranial aneurysms with desired flow modification features.
6. Computed tomography angiography in the evaluation of carotid artery bifurcation stenosis: comparison with intraarterial digital subtraction angiography; Angio-TC en la evaluacion de estenosis de la bifurcacion arterial carotidea: comparacion con arteriografia por sustraccion digital intraarterial
Santos, A. L.; Ramos, M.; Delgado, F.; Cano, A.; Bravo, F. [Hospital Universitario Reina Sofia. Cordoba (Spain)
2001-07-01
To determine the value of computed tomography (CT) angiography in grading cervical carotid artery stenosis, comparing it with that of intraarterial digital subtraction angiography (IADSA), and to demonstrate the utility of CT angiography, under certain circumstances, as an alternative to carotid angiography in the diagnosis of arterial disease. Of the 428 patients who underwent CT andiography of the supraaortic trunk in our hospital between lily 1998 and September 2000, the results in the first 55 in whom Id's was performed concomitantly were reviewed, and the findings with two techniques compared. In the discrimination of stenosis >70%, CT angiography showed a sensitivity of 92%, a specificity of 98% and an overall precision of 95% with respect to IADSA. The good correlation of the grading of carotid artery stenosis by CT angiography with that of IADSA suggests its high diagnostic reliability. (Author) 38 refs.
7. TU-CD-207-03: Time Evolution of Texture Parameters of Subtracted Images Obtained by Contrast-Enhanced Digital Mammography (CEDM)
Mateos, M-J; Brandan, M-E [Instituto de Fisica, Universidad Nacional Autonom de Mexico, Mexico, Distrito Federal (Mexico); Gastelum, A; Marquez, J [Centro de Ciencias Aplicadas y Desarrollo Tecnologico Universidad Nacional Autonoma de Mexico, Mexico, Distrito Federal (Mexico)
2015-06-15
Purpose: To evaluate the time evolution of texture parameters, based on the gray level co-occurrence matrix (GLCM), in subtracted images of 17 patients (10 malignant and 7 benign) subjected to contrast-enhanced digital mammography (CEDM). The goal is to determine the sensitivity of texture to iodine uptake at the lesion, and its correlation (or lack of) with mean-pixel-value (MPV). Methods: Acquisition of clinical images followed a single-energy CEDM protocol using Rh/Rh/48 kV plus external 0.5 cm Al from a Senographe DS unit. Prior to the iodine-based contrast medium (CM) administration a mask image was acquired; four CM images were obtained 1, 2, 3, and 5 minutes after CM injection. Temporal series were obtained by logarithmic subtraction of registered CM minus mask images.Regions of interest (ROI) for the lesion were drawn by a radiologist and the texture was analyzed. GLCM was evaluated at a 3 pixel distance, 0° angle, and 64 gray-levels. Pixels identified as registration errors were excluded from the computation. 17 texture parameters were chosen, classified according to similarity into 7 groups, and analyzed. Results: In all cases the texture parameters within a group have similar dynamic behavior. Two texture groups (associated to cluster and sum mean) show a strong correlation with MPV; their average correlation coefficient (ACC) is r{sup 2}=0.90. Other two groups (contrast, homogeneity) remain constant with time, that is, a low-sensitivity to CM uptake. Three groups (regularity, lacunarity and diagonal moment) are sensitive to CM uptake but less correlated with MPV; their ACC is r{sup 2}=0.78. Conclusion: This analysis has shown that, at least groups associated to regularity, lacunarity and diagonal moment offer dynamical information additional to the mean pixel value due to the presence of CM at the lesion. The next step will be the analysis in terms of the lesion pathology. Authors thank PAPIIT-IN105813 for support. Consejo Nacional de Ciencia Y
8. Role of biplane digital subtraction angiography, and 3D rotational angiography in craniopagus twins: A case report, detailed pictorial evaluation, and review of literature.
Sudha, Lakshmi; Dev, Bhawna; Kamble, Ravindra; Joseph, Santhosh
2009-07-01
Cranially conjoined twins (craniopagus) are regarded as one of the rarest human malformations. Craniopagus represents 2 to 6% of conjoined twins and is the rarest type of disorder. A conventional angiogram with three dimensions is needed to confirm the exact extent of sharing of the arterial / venous tree. 3D angiography was first proposed by CORNELIUS and advanced into clinical practice by VOIGT in 1975. We present a case of craniopagus vertical type II twins, evaluated for cerebral circulation.
9. Role of biplane digital subtraction angiography, and 3D rotational angiography in craniopagus twins: A case report, detailed pictorial evaluation, and review of literature
Lakshmi Sudha; Bhawna Dev; Ravindra Kamble; Santhosh Joseph
2009-01-01
Cranially conjoined twins (craniopagus) are regarded as one of the rarest human malformations. Craniopagus represents 2 to 6% of conjoined twins and is the rarest type of disorder. A conventional angiogram with three dimensions is needed to confirm the exact extent of sharing of the arterial / venous tree. 3D angiography was first proposed by CORNELIUS and advanced into clinical practice by VOIGT in 1975. We present a case of craniopagus vertical type II twins, evaluated for cerebral circulat...
10. Role of biplane digital subtraction angiography, and 3D rotational angiography in craniopagus twins: A case report, detailed pictorial evaluation, and review of literature
Lakshmi Sudha
2009-01-01
Full Text Available Cranially conjoined twins (craniopagus are regarded as one of the rarest human malformations. Craniopagus represents 2 to 6% of conjoined twins and is the rarest type of disorder. A conventional angiogram with three dimensions is needed to confirm the exact extent of sharing of the arterial / venous tree. 3D angiography was first proposed by CORNELIUS and advanced into clinical practice by VOIGT in 1975. We present a case of craniopagus vertical type II twins, evaluated for cerebral circulation.
11. Color-coded digital subtraction angiography in the management of a rare case of middle cerebral artery pure arterial malformation. A technical and case report.
Feliciano, Caleb E; Pamias-Portalatin, Eva; Mendoza-Torres, Jorge; Effio, Euclides; Moran, Yadira; Rodriguez-Mercado, Rafael
2014-12-01
The advent of flow dynamics and the recent availability of perfusion analysis software have provided new diagnostic tools and management possibilities for cerebrovascular patients. To this end, we provide an example of the use of color-coded angiography and its application in a rare case of a patient with a pure middle cerebral artery (MCA) malformation. A 42-year-old male chronic smoker was evaluated in the emergency room due to sudden onset of severe headache, nausea, vomiting and left-sided weakness. Head computed tomography revealed a right basal ganglia hemorrhage. Cerebral digital subtraction angiography (DSA) showed a right middle cerebral artery malformation consisting of convoluted and ectatic collateral vessels supplying the distal middle cerebral artery territory-M1 proximally occluded. An associated medial lenticulostriate artery aneurysm was found. Brain single-photon emission computed tomography with and without acetazolamide failed to show problems in vascular reserve that would indicate the need for flow augmentation. Twelve months after discharge, the patient recovered from the left-sided weakness and did not present any similar events. A follow-up DSA and perfusion study using color-coded perfusion analysis showed perforator aneurysm resolution and adequate, albeit delayed perfusion in the involved vascular territory. We propose a combined congenital and acquired mechanism involving M1 occlusion with secondary dysplastic changes in collateral supply to the distal MCA territory. Angiographic and cerebral perfusion work-up was used to exclude the need for flow augmentation. Nevertheless, the natural course of this lesion remains unclear and long-term follow-up is warranted.
12. Three-dimensional time-of-flight MR angiography for evaluation of intracranial aneurysms after endosaccular packing with Guglielmi detachable coils: comparison with 3D digital subtraction angiography
Okahara, Mika [Department of Radiology, Nagatomi Neurosurgical Hospital, Oita (Japan); Department of Radiology, Oita University Faculty of Medicine, 1-1 Hasama-machi, 879-5503, Oita (Japan); Kiyosue, Hiro; Mori, Hiromu [Department of Radiology, Oita University Faculty of Medicine, 1-1 Hasama-machi, 879-5503, Oita (Japan); Hori, Yuzo [Department of Radiology, Nagatomi Neurosurgical Hospital, Oita (Japan); Yamashita, Masanori; Nagatomi, Hirofumi [Department of Neurosurgery, Nagatomi Neurosurgical Hospital, Oita (Japan)
2004-07-01
The sensitivities and specificities of three-dimensional time-of-flight MR angiography (3D-TOF MRA) and 3D digital subtraction angiography (3D-DSA) were compared for evaluation of cerebral aneurysms after endosaccular packing with Guglielmi detachable coils (GDCs). Thirty-three patients with 33 aneurysms were included in this prospective study. 3D-TOF MRA and 3D-DSA were performed in the same week on all patients. Maximal intensity projection (MIP) and 3D reconstructed MRA images were compared with 3D-DSA images. The diameters of residual/recurrent aneurysms detected on 3D-DSA were calculated on a workstation. In 3 (9%) of 33 aneurysms, 3D-TOF MRA did not provide reliable information due to significant susceptibility artifacts on MRA. The sensitivity and specificity rates of MRA were 72.7 and 90.9%, respectively, for the diagnosis of residual/recurrent aneurysm. The diameters of residual/recurrent aneurysms that could not be detected by MRA were significantly smaller than those of detected aneurysms (mean 1.1 vs mean 2.3 mm). In one aneurysm of the anterior communicating artery (ACoA), the relationship between the residual aneurysm and the ACoA was more evident on MRA than DSA images. MRA can detect the recurrent/residual lumen of aneurysms treated with GDCs of up to at least 1.8 mm in diameter. 3D-TOF MRA is useful for follow-up of intracranial aneurysms treated with GDCs, and could partly replace DSA. (orig.)
13. Time-of-flight MR angiography at 3 T versus digital subtraction angiography in the imaging follow-up of 51 intracranial aneurysms treated with coils
Ferre, Jean-Christophe [Department of Neuroradiology, Hopital Pontchaillou, University Hospital Rennes, 2 rue Henri Le Guilloux, 35000 Rennes (France)], E-mail: [email protected]; Carsin-Nicol, Beatrice [Department of Neuroradiology, Hopital Pontchaillou, University Hospital Rennes, 2 rue Henri Le Guilloux, 35000 Rennes (France); Morandi, Xavier [Department of Neurosurgery, Hopital Pontchaillou, University Hospital Rennes, 2 rue Henri Le Guilloux, 35000 Rennes (France); Carsin, Michel [Department of Neuroradiology, Hopital Pontchaillou, University Hospital Rennes, 2 rue Henri Le Guilloux, 35000 Rennes (France); Kersaint-Gilly, Axel de [Department of Neuroradiology, Hopital Laennec, University Hospital Nantes, Boulevard Jacques Monod, 44800 Saint-Herblain (France); Gauvrit, Jean-Yves [Department of Neuroradiology, Hopital Pontchaillou, University Hospital Rennes, 2 rue Henri Le Guilloux, 35000 Rennes (France); Desal, Hubert-Armand [Department of Neuroradiology, Hopital Laennec, University Hospital Nantes, Boulevard Jacques Monod, 44800 Saint-Herblain (France)
2009-12-15
Objective: To compare 3D time-of-flight MR angiography (TOF-MRA) at 3 Tesla (3 T) with digital subtraction angiography (DSA) for the evaluation of intracranial aneurysm occlusion after endovascular coiling. Methods: In a prospective study, 51 consecutive patients (25 females, 26 males; median age, 51 years) with 51 saccular aneurysms treated with endovascular coiling underwent simultaneous DSA and 3 T TOF-MRA at follow-up. DSA and TOF-MRA images were analyzed independently by two senior neuroradiologists. Findings were assigned to 1 of 3 categories in the Raymond classification: complete obliteration, residual neck or residual aneurysm. Agreement between observers and techniques was evaluated using {kappa} statistics. Results: DSA images were not interpretable for one patient. Interobserver agreement was determined as excellent for DSA ({kappa} = 0.86) and TOF-MRA ({kappa} = 0.80). After reaching a consensus, DSA follow-up showed 26 (51%) complete obliterations, 20 (39%) residual necks and 4 (8%) residual aneurysms. TOF-MRA showed 23 (45%) complete obliterations, 22 (43%) residual necks and 6 (12%) residual aneurysms. Comparison between TOF-MRA and DSA showed excellent agreement between the techniques ({kappa} = 0.86). In the four cases that were misclassified, TOF-MRA findings were assigned to a higher class than for DSA. Conclusion: TOF-MRA at 3 T is at least as efficient as DSA for the evaluation of intracranial aneurysm occlusion after endovascular treatment with detachable coils. We suggest that TOF-MRA at 3 T might be used as the primary method for imaging follow-up of coiled intracranial aneurysms.
14. Contrast-enhanced angiographic computed tomography for detection of aneurysm remnants after clipping: a comparison with digital subtraction angiography in 112 clipped aneurysms.
Gölitz, Philipp; Struffert, Tobias; Ganslandt, Oliver; Lang, Stefan; Knossalla, Frauke; Doerfler, Arnd
2014-06-01
For preclusion of remnants after aneurysm clipping, a reliable, noninvasive imaging technique is desirable. To evaluate the reliability of optimized angiographic computed tomography with intravenous contrast agent injection (ivACT) in detecting remnants after aneurysmal clipping compared with digital subtraction angiography (DSA), the gold standard. We included 84 patients with 112 clipped cerebral aneurysms of the anterior circulation. For treatment, 116 clips of cobalt and 57 clips of titanium alloy were used. In each patient, we performed an ivACT with dual rotational acquisition and a DSA. Data from ivACT were postprocessed with a dual-volume technique with newly implemented reconstructions modes. Aneurysm remnants were measured, classified, and correlated with DSA by 2 raters. In total, 12 remnants were revealed by DSA, meaning a prevalence of 11%. IvACT demonstrated a sensitivity of 75% to 92% and a specificity of 99% in detecting remnants up to a minimal size of 0.7 × 0.3 mm. Classification of remnants by ivACT was identical to that by DSA, and assessment of size showed a significant correlation with DSA (P < .001). No significant differences between cobalt and titanium alloy were revealed concerning artifacts. Optimized ivACT with enhanced postprocessing demonstrated high sensitivity and specificity in detecting remnants after aneurysm clipping in the anterior circulation. Classification and assessment of remnant size and detection of relevant parent artery stenosis showed high accuracy of ivACT compared with DSA. Our results indicate that ivACT might become a noninvasive alternative to DSA for postsurgical control.
15. Non-enhanced, ECG-gated MR angiography of the pedal vasculature: comparison with contrast-enhanced MR angiography and digital subtraction angiography in peripheral arterial occlusive disease.
Schubert, Tilman; Takes, Martin; Aschwanden, Markus; Klarhoefer, Markus; Haas, Tanja; Jacob, Augustinus L; Liu, David; Gutzeit, Andreas; Kos, Sebastian
2016-08-01
This study was conducted in order to compare a high resolution, non-contrast-enhanced MRA (NATIVE SPACE, NE-MRA) of the pedal vasculature with contrast-enhanced MRA (CE-MRA) and digital subtraction angiography (DSA) in patients with peripheral arterial occlusive disease (PAOD). The prospective study consists of 20 PAOD patients. All patients underwent percutaneous transluminal angioplasty or stenting and received MR angiographies the following day. With CE-MRA, 75.7 % of vessel segments showed good, 16.4 % suboptimal and 7.9 % not usable image quality. With NE-MRA, 64.6 % showed good, 18.6 % suboptimal and 16.8 % not usable image quality. CE-MRA showed a sensitivity and negative predictive value of 90 %/95 % regarding significant stenosis (greater than 50 %), and specificity and positive predictive value were 88 %/77 %. Accordingly, sensitivity and negative predictive value for the NE-MRA were 96 %/97 % and specificity and positive predictive value were 80 %/69 % for stenoses greater than 50 %. The applied NE-MRA technique achieves high diagnostic accuracy even in very small distal arteries of the foot. However, the rate of non-diagnostic vessel segments is considerably higher for NE-MRA than for CE-MRA. NE-MRA is a valuable alternative to CE-MRA in selected patients. • Comparison of non-enhanced MRA with contrast-enhanced MRA and DSA as gold standard. • High resolution MRA at 3 T for the depiction of small pedal vessels. • Evaluation of high resolution non-enhanced MRA in PAOD patients.
16. A prospective feasibility study of duplex ultrasound arterial mapping, digital-subtraction angiography, and magnetic resonance angiography in management of critical lower limb ischemia by endovascular revascularization.
Lowery, A J; Hynes, N; Manning, B J; Mahendran, M; Tawfik, S; Sultan, S
2007-07-01
Duplex ultrasound arterial mapping (DUAM) allows precise evaluation of peripheral vascular disease (PVD). However, magnetic resonance angiography (MRA) and digital-subtraction angiography (DSA) are the diagnostic tools used most frequently prior to intervention. Our aim was to compare clinical pragmatism, hemodynamic outcomes, and cost-effectiveness when using DUAM alone compared to DSA or MRA as preoperative assessment tools for endovascular revascularization (EvR) in critical lower limb ischemia (CLI). From 2002 through 2005, 465 patients were referred with PVD. Of these, 199 had CLI and 137 required EvR. Preoperative diagnostic evaluation included DUAM (n = 41), DSA (n = 50), or MRA (n = 46). EvR was aortoiliac in 27% of cases and infrainguinal in 73%. Patients were assessed at day 1, 6 weeks, 3 months, and 6 months. Composite end points were relief of rest pain, ulcer/gangrene healing, and increase in perfusion pressure, as measured by ankle-brachial index (ABI) and digital pressures. Patency by DUAM, limb salvage, morbidity, mortality, length of stay, and cost-effectiveness were compared between groups using nonparametric t-test, analysis of variance, and Kaplan-Meier analysis. The three groups were comparable in terms of age, sex, comorbidity, and Society for Vascular Surgery/International Society of Cardiovascular Surgery clinical classification. Six-month mean improvement in ABI in the DUAM group was comparable to that in the DSA group (P = 0.25) and significantly better than that in the MRA group (P < 0.05). Six-month patency rates for the DUAM group were comparable to those in the DSA group (P = 0.68, relative risk [RR] = 0.74, 95% confidence interval [CI] 0.18-2.99) and superior to that in the MRA group (P = 0.022, RR = 0.255, 95% CI 0.09-0.71). Length of hospital stay was lower in the DUAM group compared with the DSA group (P < 0.0001) and the MRA group (P = 0.0003). The cost of DUAM is lower than that of both DSA and MRA. DUAM accurately identified the
17. Evaluation of Anterior Ethmoidal Artery by 320-Slice CT Angiography with Comparison to Three-Dimensional Spin Digital Subtraction Angiography: Initial Experiences
Ding, Juan; Sun, Gang; Yu, Bling Bing; Li, Min; Li, Guo Ying; Peng, Zhao Hui; Zhang, Xu Ping [Dept. of Medical Imaging, Jinan Military General Hospital, Jinan (China); Lu, Yang [Dept. of Radiology, University of Illinois College of Medicine, Illinois (United States)
2012-11-15
To explore the usefulness of 320-slice CT angiography (CTA) for evaluating the course of the anterior ethmoidal artery (AEA) and its relationship with adjacent structures by using three-dimensional (3D) spin digital subtraction angiography (DSA) as standard reference. From December 2008 to December 2010, 32 patients with cerebrovascular disease, who underwent both cranial 3D spin DSA and 320-slice CTA within a 30 day period from each other, were retrospectively reviewed. AEA course in ethmoid was analyzed in DSA and CTA. In addition, adjacent bony landmarks (bony notch in medial orbital wall, anterior ethmoidal canal, and anterior ethmoidal sulcus) were evaluated with CTA using the MPR technique oriented along the axial, coronal and oblique coronal planes in all patients. The dose length product (DLP) for CTA and the dose-area product (DAP) for 3D spin DSA were recorded. Effective dose (ED) was calculated. The entire course of the AEA was seen in all 32 cases (100%) with 3D spine DSA and in 29 of 32 cases (90.1%) with 320-slice CTA, with no significant difference (p = 0.24). In three cases where AEA was not visualized on 320-slice CTA, two were due to the dominant posterior ethmoidal artery, while the remaining case was due to diminutive AEA. On MPR images of 320-slice CT, a bony notch in the orbital medial walls was detected in all cases (100%, 64 of 64); anterior ethmoidal canal was seen in 28 of 64 cases (43.8%), and the anterior ethmoidal sulcus was seen in 63 of 64 cases (98.4%). The mean effective dose in CTA was 0.6 {+-} 0.25 mSv, which was significantly lower than for 3D spin DSA (1.3 {+-} 0.01 mSv) (p < 0.001). 320-slice CTA has a similar detection rate for AEA to that of 3D spin DSA; however, it is noninvasive, and may be preferentially used for the evaluation of AEA and its adjacent bony variations and pathologic changes in preoperative patients with paranasal sinus diseases.
18. Internal carotid artery stenosis: accuracy of subjective visual impression for evaluation with digital subtraction angiography and contrast-enhanced MR angiography.
U-King-Im, Jean Marie; Graves, Martin J; Cross, Justin J; Higgins, Nicholas J; Wat, Josephine; Trivedi, Rikin A; Tang, Tjun; Howarth, Simon P S; Kirkpatrick, Peter J; Antoun, Nagui M; Gillard, Jonathan H
2007-07-01
To prospectively determine, for both digital subtraction angiography (DSA) and contrast material-enhanced magnetic resonance (MR) angiography, the accuracy of subjective visual impression (SVI) in the evaluation of internal carotid artery (ICA) stenosis, with objective caliper measurements serving as the reference standard. Local ethics committee approval and written informed patient consent were obtained. A total of 142 symptomatic patients (41 women, 101 men; mean age, 70 years; age range, 44-89 years) suspected of having ICA stenosis on the basis of Doppler ultrasonographic findings underwent both DSA and contrast-enhanced MR angiography. With each modality, three independent neuroradiologists who were blinded to other test results first visually estimated and subsequently objectively measured stenoses. Diagnostic accuracy and percentage misclassification for correct categorization of 70%-99% stenosis were calculated for SVI, with objective measurements serving as the reference standard. Interobserver variability was determined with kappa statistics. After exclusion of arteries that were unsuitable for measurement, 180 vessels remained for analysis with DSA and 159 vessels remained for analysis with contrast-enhanced MR angiography. With respect to 70%-99% stenosis, SVI was associated with average misclassification of 8.9% for DSA (8.9%, 7.8%, and 10.0% for readers A, B, and C, respectively) and of 11.7% for contrast-enhanced MR angiography (11.3%, 8.8%, and 15.1% for readers A, B, and C, respectively). Negative predictive values were excellent (92.3%-100%). Interobserver variability was higher for SVI (DSA, kappa = 0.62-0.71; contrast-enhanced MR angiography, kappa = 0.57-0.69) than for objective measurements (DSA, kappa = 0.75-0.80; contrast-enhanced MR angiography, kappa = 0.66-0.72). SVI alone is not recommended for evaluation of ICA stenosis with both DSA and contrast-enhanced MR angiography. SVI may be acceptable as an initial screening tool to exclude the
19. Carbon dioxide (CO{sub 2}) digital subtraction angiography. Evaluation of a new delivery system; Angiografia con anidride carbonica. Nuovo sistema di iniezione
Nicolini, A.; Lovaria, A.; Meregaglia, D. [Ospedale Maggiore IRCCS Policlinico, Milan (Italy). Dipt. di Scienze Radiologiche; Palatresi, S. [Ospedale Maggiore IRCCS Policlinico, Milan (Italy). Ist. di Clinica Medica Generale e Terapia Medica
2000-02-01
Purpose of this work is to evaluate the usefulness of a new carbon dioxide (CO{sub 2}) intravascular injection system in digital subtraction angiography. March 1998 to May 1999, 39 patients were submitted to digital subtraction angiography with CO{sub 2} injection by a new delivery system, CO{sub 2}-Angio set, OptiMed, Ettingen, Germany. The patients were 29 men and 10 women, whose age ranged 32 to 76 (mean: 47), 18 of them with absolute or relative contraindications to iodinated contrast media and 6 with poor diagnostic findings at previous conventional angiography. CO{sub 2} was used for comparison with iodinated contrast agents in 4 patients. It was studied the following vascular districts: renal arteries in 9 patients, portal vein in 18, lower limb arteries in 7, upper limb veins in 4. In 1 patient CO{sub 2} angiography was carried out for the diagnosis and interventional treatment, by transcatheter embolization, of a postbioptic arteriovenous renal fistula. During the procedure, arterial blood pressure, EKG status and oxygen saturation were monitored, and subjective sensations recorded in all patients. CO{sub 2} angiography provided adequate visualization of vascular districts and of abnormal findings in 32 cased (82%), while its results were considered insufficient for correct and complete assessment in 7 cases (18%). CO{sub 2}-Angio set delivery system has proved to be a simple and safe tool, particularly suitable for use in patients at risk for allergic reactions to iodinated contrast agents and in those with renal function impairment. Also, the system can help carry out some interventional procedures such as arteriovenous fistula embolization and trans jugular portosystemic shunting. [Italian] Scopo di questo articolo e' verificare la validita' e l'efficacia di un nuovo sistema di iniezione angiografico per anidride carbonica. Da marzo 1998 a maggio 1999 sono stati sottoposti ad angiografia con anidride carbonica mediante sistema non
20. Aneurysm shape reconstruction from biplane angiograms in the ISUIA collection
Raghavan, Madhavan L; Sharda, Gaurav V; Huston, John; Mocco, J; Capuano, Ana W; Torner, James C; Saha, Punam K; Meissner, Irene; Brown, Robert D; Groen, Rob
2014-01-01
The International Study of Unruptured Intracranial Aneurysms (ISUIA) is an epidemiologic international study of the natural history of unruptured intracranial aneurysms that enrolled 4,060 subjects. A conventional biplane cerebral angiogram available for central review was required for enrollment re
1. Value of radionuclide angiogram for the diagnosis of Ebstein's anomaly.
Gould, L; Gopalaswamy, C; Yang, D; Patel, D M; Kim, B S; Patel, C
1984-12-01
A radionuclide angiogram in a patient with Ebstein's anomaly showed a very dilated right atrium with a minimally enlarged right ventricle and a normal sized left ventricle. This study led to the establishment of a definitive diagnosis by means of an echocardiogram. Late close of the tricuspid valve was demonstrated. In addition prolapse of the tricuspid and mitral valves was documented. A tricuspid valve prolapse has never been reported in this condition.
2. The value of three-dimension digital subtraction angiography in cerebro-vascular diseases%3D-DSA在脑血管疾病诊断中的应用价值
刘康; 缪南东; 任勇军; 徐浩; 闵旭立; 杨林; 张小明
2015-01-01
Objective:To study the value of three-dimension digital subtraction angiography (3D-DSA) in cerebrovascular dis-eases. Methods:A retrospective analysis of 208 patients who underwent both 2D-DSA and 3D-DSA for evaluation of previously untreat-ed cerebrovascular diseases was conducted. The data of 2D-DSA and 3D-DSA images were analyzed. Results:Among the 208 patients, there are 128 patients with artery aneurysm,and 29 with artery stenosis or obstruction,22 with AVM,10 with moyamoya disease and 4 intracranial tumors. The detection rate of 2D-DSA is 80. 3%,while the rate of 3D-DSA is 92. 8%. This difference was significant in sta-tistics ( P< 0. 05 ) . Conclusion:Three-dimension DSA plays an important role in diagnosis and treatment of cerebrovascular diseases, and is an optimized and complemental imaging technique of 2D-DSA.%目的：：探讨三维数字减影血管造影(three-dimension digital subtraction angiography,3D-DSA)在脑血管疾病诊断中的应用价值。方法：对临床怀疑脑血管疾病患者208例,同时进行常规DSA(2D-DSA)和3D-DSA检查,并对结果进行对比分析。结果：208例中,检出动脉瘤128例,脑动脉狭窄或闭塞29例,动静脉畸22例,烟雾病10例,脑肿瘤4例。2D-DSA病变检出率80．3%(167/208)；3D-DSA病变检出率92．8%(193/208)；两组检出率差异具有统计学意义(P<0．05)。结论：3D-DSA在脑血管疾病诊断中具有重要的应用价值,是2D-DSA的优化和补充。
3. Suppression subtractive hybridization.
Ghorbel, Mohamed T; Murphy, David
2011-01-01
Comparing two RNA populations that differ from the effects of a single independent variable, such as a drug treatment or a specific genetic defect, can establish differences in the abundance of specific transcripts that vary in a population dependent manner. There are different methods for identifying differentially expressed genes. These methods include microarray, Serial Analysis of Gene Expression (SAGE), and quantitative Reverse-Transcriptase Polymerase Chain Reaction (qRT-PCR). Herein, the protocol describes an easy and cost-effective alternative that does not require prior knowledge of the transcriptomes under examination. It is specifically relevant when low levels of RNA starting material are available. This protocol describes the use of Switching Mechanism At RNA Termini Polymerase Chain Reaction (SMART-PCR) to amplify cDNA from small amounts of RNA. The amplified cDNA populations under comparison are then subjected to Suppression Subtractive Hybridization (SSH-PCR). SSH-PCR is a technique that couples subtractive hybridization with suppression PCR to selectively amplify fragments of differentially expressed genes. The resulting products are cDNA populations enriched for significantly overrepresented transcripts in either of the two input RNAs. These cDNA populations can then be cloned to generate subtracted cDNA library. Microarrays made with clones from the subtracted forward and reverse cDNA libraries are then screened for differentially expressed genes using targets generated from tester and driver total RNAs.
4. Transient Loss of Vision after Coronary Angiogram - A Case Report.
Pasha, K; Sengupta, P; Alauddin, S; Sheikh, A K; Hossain, M Z; Sumon, S M
2015-07-01
A 50-year old, diabetic, hypertensive patient with post-CABG status developed complete loss of vision about one hour after coronary angiogram (CAG). Thorough ophthalmological and neurological examination as well as magnetic resonance imaging of brain especially of the occipital region revealed no abnormality. The patient had complete recovery of vision about 48 hours later. We could not document any specific cause or mechanism for the visual loss, although the selective vulnerability of occipital lobes to contrast agent toxicity (Cortical blindness) was the most likely underlying mechanism.
5. Outcome following a negative CT Angiogram for gastrointestinal hemorrhage.
Chan, Victoria; Tse, Donald; Dixon, Shaheen; Shrivastava, Vivek; Bratby, Mark; Anthony, Suzie; Patel, Rafiuddin; Tapping, Charles; Uberoi, Raman
2015-04-01
This study was designed to evaluate the role of a negative computed tomography angiogram (CTA) in patients who present with gastrointestinal (GI) hemorrhage. A review of all patients who had CTAs for GI hemorrhage over an 8-year period from January 2005 to December 2012 was performed. Data for patient demographics, location of hemorrhage, hemodynamic stability, and details of angiograms and/or the embolization procedure were obtained from the CRIS/PACS database, interventional radiology database, secure electronic medical records, and patient's clinical notes. A total of 180 patients had 202 CTAs during the 8-year period: 87 CTAs were performed for upper GI hemorrhage (18 positive for active bleeding, 69 negative) and 115 for lower GI hemorrhage (37 positive for active bleeding, 78 negative); 58.7 % (37/63) of patients with upper GI bleed and 77.4 % (48/62) of patients with lower GI bleed who had an initial negative CTA did not rebleed without the need for radiological or surgical intervention. This difference was statistically significant (p = 0.04). The relative risk of rebleeding, following a negative CTA, in lower GI bleeding versus upper GI bleeding patients is 0.55 (95 % confidence interval 0.32-0.95). Patients with upper GI bleed who had negative CTAs usually require further intervention to stop the bleeding. In contrast, most patients presenting with lower GI hemorrhage who had a negative first CTA were less likely to rebleed.
6. Segmentation of choroidal neovascularization in fundus fluorescein angiograms.
Abdelmoula, Walid M; Shah, Syed M; Fahmy, Ahmed S
2013-05-01
Choroidal neovascularization (CNV) is a common manifestation of age-related macular degeneration (AMD). It is characterized by the growth of abnormal blood vessels in the choroidal layer causing blurring and deterioration of the vision. In late stages, these abnormal vessels can rupture the retinal layers causing complete loss of vision at the affected regions. Determining the CNV size and type in fluorescein angiograms is required for proper treatment and prognosis of the disease. Computer-aided methods for CNV segmentation is needed not only to reduce the burden of manual segmentation but also to reduce inter- and intraobserver variability. In this paper, we present a framework for segmenting CNV lesions based on parametric modeling of the intensity variation in fundus fluorescein angiograms. First, a novel model is proposed to describe the temporal intensity variation at each pixel in image sequences acquired by fluorescein angiography. The set of model parameters at each pixel are used to segment the image into regions of homogeneous parameters. Preliminary results on datasets from 21 patients with Wet-AMD show the potential of the method to segment CNV lesions in close agreement with the manual segmentation.
7. Technical innovation: Multidimensional computerized software enabled subtraction computed tomographic angiography.
Bhatia, Mona; Rosset, Antoine; Platon, Alexandra; Didier, Dominique; Becker, Christoph D; Poletti, Pierre-Alexandre
2010-01-01
Computed tomographic angiography (CTA) is a frequent noninvasive alternative to digital subtraction angiography. We previously reported the development of a new subtraction software to overcome limitations of adjacent bone and calcification in CT angiographic subtraction. Our aim was to further develop and improve this fast and automated computerized software, universally available for free use and compatible with most CT scanners, thus enabling better delineation of vascular structures, artifact reduction, and shorter reading times with potential clinical benefits. This computer-based free software will be available as an open source in the next release of OsiriX at the Web site http://www.osirix-viewer.com.
8. The value of MRI in angiogram-negative intracranial haemorrhage
1994-08-01
In one year, cerebral angiograms were performed for intracranial haemorrhage (ICH) on 334 patients. No cause for haemorrhage could be identified in 41 (12 %), 30 of whom had predominantly subarachnoid (SAH) and 11 predominantly parenchymal haemorrhage (PH). These patients were prospectively examined by cranial MRI 1-6 weeks after the ictus. The MRI studies were positive in 7 patients (17 %). In the 30 patients examined after SAH, 2 studies were positive, showing an aneurysm in one case and a brain stem lesion of uncertain aetiology in the other. In those examined after PH, cavernous angiomas were shown in 2, a tumour in 1 and a vascular malformation in another; useful diagnostic information was thus obtained in 36 % of this group. (orig.)
9. Vessel extraction in X-ray angiograms using deep learning.
Nasr-Esfahani, E; Samavi, S; Karimi, N; Soroushmehr, S M R; Ward, K; Jafari, M H; Felfeliyan, B; Nallamothu, B; Najarian, K
2016-08-01
Coronary artery disease (CAD) is the most common type of heart disease which is the leading cause of death all over the world. X-ray angiography is currently the gold standard imaging technique for CAD diagnosis. These images usually suffer from low quality and presence of noise. Therefore, vessel enhancement and vessel segmentation play important roles in CAD diagnosis. In this paper a deep learning approach using convolutional neural networks (CNN) is proposed for detecting vessel regions in angiography images. Initially, an input angiogram is preprocessed to enhance its contrast. Afterward, the image is evaluated using patches of pixels and the network determines the vessel and background regions. A set of 1,040,000 patches is used in order to train the deep CNN. Experimental results on angiography images of a dataset show that our proposed method has a superior performance in extraction of vessel regions.
10. Colourful FKS subtraction
Frixione, Stefano
2011-01-01
I formulate in a colour-friendly way the FKS method for the computation of QCD cross sections at the next-to-leading order accuracy. This is achieved through the definition of subtraction terms for squared matrix elements, constructed with single colour-dressed or pairs of colour-ordered amplitudes. The latter approach relies on the use of colour flows, is exact to all orders in $N$, and is thus particularly suited to being organized as a systematic expansion in 1/N.
11. Outcome Following a Negative CT Angiogram for Gastrointestinal Hemorrhage
Chan, Victoria, E-mail: [email protected]; Tse, Donald, E-mail: [email protected]; Dixon, Shaheen, E-mail: [email protected] [John Radcliffe Hospital, Department of Radiology, Level 2 (United Kingdom); Shrivastava, Vivek, E-mail: [email protected] [Hull Royal Infirmary, Department of Radiology (United Kingdom); Bratby, Mark, E-mail: [email protected]; Anthony, Suzie, E-mail: [email protected]; Patel, Rafiuddin, E-mail: [email protected]; Tapping, Charles, E-mail: [email protected]; Uberoi, Raman, E-mail: [email protected] [John Radcliffe Hospital, Department of Radiology, Level 2 (United Kingdom)
2015-04-15
ObjectiveThis study was designed to evaluate the role of a negative computed tomography angiogram (CTA) in patients who present with gastrointestinal (GI) hemorrhage.MethodsA review of all patients who had CTAs for GI hemorrhage over an 8-year period from January 2005 to December 2012 was performed. Data for patient demographics, location of hemorrhage, hemodynamic stability, and details of angiograms and/or the embolization procedure were obtained from the CRIS/PACS database, interventional radiology database, secure electronic medical records, and patient’s clinical notes.ResultsA total of 180 patients had 202 CTAs during the 8-year period: 87 CTAs were performed for upper GI hemorrhage (18 positive for active bleeding, 69 negative) and 115 for lower GI hemorrhage (37 positive for active bleeding, 78 negative); 58.7 % (37/63) of patients with upper GI bleed and 77.4 % (48/62) of patients with lower GI bleed who had an initial negative CTA did not rebleed without the need for radiological or surgical intervention. This difference was statistically significant (p = 0.04). The relative risk of rebleeding, following a negative CTA, in lower GI bleeding versus upper GI bleeding patients is 0.55 (95 % confidence interval 0.32–0.95).ConclusionsPatients with upper GI bleed who had negative CTAs usually require further intervention to stop the bleeding. In contrast, most patients presenting with lower GI hemorrhage who had a negative first CTA were less likely to rebleed.
12. Computed tomography hepatic arteriography has a hepatic falciform artery detection rate that is much higher than that of digital subtraction angiography and 99mTc-MAA SPECT/CT: Implications for planning 90Y radioembolization?
2012-12-15
Purpose: To compare the hepatic falciform artery (HFA) detection rates of digital subtraction angiography (DSA), computed tomography hepatic arteriography (CTHA) and 99mTc-macroaggregated albumin (99mTc-MAA) single photon emission computed tomography with integrated CT (SPECT/CT) and to correlate HFA patency with complication rates of yttrium-90 (90Y) radioembolization. Material and methods: From August 2008 to November 2010, 79 patients (range 23–83 years, mean 62.3 years; 67 male) underwent pre-treatment DSA, CTHA and 99mTc-MAA scintigraphy (planar/SPECT/CT) to assess suitability for radioembolization with 90Y resin microspheres. Thirty-seven patients were excluded from the study, because CTHA was performed with a catheter position that did not result in opacification of the liver parenchyma adjacent to the falciform ligament. DSA, CTHA and 99mTc-MAA SPECT/CT images and medical records were retrospectively reviewed. Results: A patent HFA was detected in 22 of 42 patients (52.3%). The HFA detection rates of DSA, CTHA and 99mTc-MAA SPECT/CT were 11.9%, 52.3% and 13.3%, respectively (p < 0.0001). An origin from the segment 4 artery was seen in 51.7% of HFAs. Prophylactic HFA coil-embolization prior to 90Y microspheres infusion was performed in 2 patients. Of the patients who underwent radioembolization with a patent HFA, none developed supra-umbilical radiation dermatitis. One patient experienced epigastric pain attributed to post-embolization syndrome and was managed conservatively. Conclusion: The HFA detection rate of CTHA is superior to that of DSA and 99mTc-MAA SPECT/CT. Complications related to non-target radiation of the HFA vascular territory rarely occur, even in patients undergoing radioembolization with a patent HFA.
13. Image Quality and Stenosis Assessment of Non-Contrast-Enhanced 3-T Magnetic Resonance Angiography in Patients with Peripheral Artery Disease Compared with Contrast-Enhanced Magnetic Resonance Angiography and Digital Subtraction Angiography.
Liu, Jiayi; Zhang, Nan; Fan, Zhaoyang; Luo, Nan; Zhao, Yike; Bi, Xiaoming; An, Jing; Chen, Zhong; Liu, Dongting; Wen, Zhaoying; Fan, Zhanming; Li, Debiao
2016-01-01
To evaluate the diagnostic performance of flow-sensitive dephasing (FSD)-prepared steady-state free precession (SSFP) magnetic resonance angiography (MRA) at 3 T for imaging infragenual arteries relative to contrast-enhanced MRA (CE-MRA) and digital subtraction angiography (DSA). A series of 16 consecutive patients with peripheral arterial disease (PAD) underwent a combined peripheral MRA protocol consisting of FSD-MRA for the calves and large field-of-view CE-MRA. DSA was performed on all patients within 1 week of the MR angiographies. Image quality and degree of stenosis was assessed by two readers with rich experience. Inter-observer agreement was determined using kappa statistics. Receiver operating characteristic (ROC) curve analysis determined the diagnostic value of FSD-MRA, CE-MRA, and CE-MRA combined with FSD-MRA (CE+FSD MRA) in predicting vascular stenosis. At the calf station, no significantly difference of subjective image quality scores was found between FSD-MRA and CE-MRA. Inter-reader agreement was excellent for both FSD-MRA and CE-MRA. Both of FSD-MRA and CE-MRA carry a stenosis overestimation risk relative to DSA standard. With DSA as the reference standard, ROC curve analysis showed that the area under the curve was largest for CE+FSD MRA. The greatest sensitivity and specificity were obtained when a cut-off stenosis score of 2 was used. In patients with severe PAD,3 T FSD-MRA provides good-quality diagnostic images without a contrast agent and is a good supplement for CE-MRA. CE+FSD MRA can improve the accuracy of vascular stenosis diagnosis.
14. Intra-arterial MR-angiography on an open-bore MR-scanner compared to digital-subtraction angiography of the infra-popliteal runoff in patients with peripheral arterial occlusive disease
Huegli, Rolf W. [Department of Radiology University Hospital of Basel, Petersgraben 4, 4031 Basel (Switzerland)], E-mail: [email protected]; Thalhammer, Christoph [Department of Angiology, University Hospital of Basel, Petersgraben 4, 4031 Basel (Switzerland)], E-mail: [email protected]; Jacob, Augustinus L. [Department of Radiology University Hospital of Basel, Petersgraben 4, 4031 Basel (Switzerland)], E-mail: [email protected]; Jaeger, Kurt [Department of Angiology, University Hospital of Basel, Petersgraben 4, 4031 Basel (Switzerland)], E-mail: [email protected]; Bilecen, Deniz [Department of Radiology University Hospital of Basel, Petersgraben 4, 4031 Basel (Switzerland)], E-mail: [email protected]
2008-06-15
Purpose: To evaluate the diagnostic value of contrast-enhanced intra-arterial 3D-MR-angiography (IA-MRA) of the infra-popliteal arteries in an open-bore magnet. Number, severity of arterial lesions, and artefacts were compared to routinely performed intra-arterial digital-subtraction angiography (IA-DSA) in patients suffering from symptomatic peripheral arterial occlusive disease (PAOD). Material and methods: Fifteen patients admitted for PAOD underwent percutaneous transluminal angioplasty (PTA) by IA-DSA. After PTA, IA-MRA of the infra-popliteal station was performed on an open-bore 1.5 T MR-scanner applying a low dose intra-arterial contrast-enhanced 3D-gradient-echo-MRA with gadopentate dimeglumine. The reading was performed by three blinded readers distinguishing moderate ({<=}50%), significant stenoses (51-99%) and vessel occlusions. Imaging artefacts were recorded and binary classified as not disturbing or compromising the observation of the arterial tree. Results: Overall IA-DSA revealed 36 moderate stenoses ({<=}50%), 38 significant stenoses (51-99%), and 10 vessel occlusions. For the detection of significant stenoses and occlusions, the overall sensitivity, specificity, positive predictive value, negative predictive value and accuracy of IA-MRA were 96%, 83%, 88%, 94% and 90%. The only observed artefact was venous overlay in four stations. The readout was not hampered in any case. Conclusion: Intra-arterial contrast-enhanced 3D-gradient-echo-MRA on an open-bore MR-scanner offers an acceptable diagnostic accuracy in diagnosing peripheral arterial occlusive disease in the infra-popliteal region and correlates well with DSA.
15. A Workflow for Patient-Individualized Virtual Angiogram Generation Based on CFD Simulation
Jürgen Endres
2012-01-01
Full Text Available Increasing interest is drawn on hemodynamic parameters for classifying the risk of rupture as well as treatment planning of cerebral aneurysms. A proposed method to obtain quantities such as wall shear stress, pressure, and blood flow velocity is to numerically simulate the blood flow using computational fluid dynamics (CFD methods. For the validation of those calculated quantities, virtually generated angiograms, based on the CFD results, are increasingly used for a subsequent comparison with real, acquired angiograms. For the generation of virtual angiograms, several patient-specific parameters have to be incorporated to obtain virtual angiograms which match the acquired angiograms as best as possible. For this purpose, a workflow is presented and demonstrated involving multiple phantom and patient cases.
16. Application of a Morse filter in the processing of brain angiograms
Venegas Bayona, Santiago
2014-06-01
The angiograms are frequently used to find anomalies in the blood vessels. Hence, for improving the quality of the images with an angiogram, a Morse filter will be implemented (based on the model of the Morse Potential) in a brain's vessels angiogram using both softwares Maple ® and ImageJ ®. It will be shown the results of applying a Morse filter to an angiogram of the brain vessels. First, the image was processed with ImageJ using the plug-in Anisotropic Diffusion 2D and then, the filter was implemented. As it is illustrated in the results, the edges of the stringy elements are emphasized. Particularly, this is very useful in the medical image processing of blood vessels, like angiograms, due to the narrowing or obstruction which may be caused by illness like aneurysms, thrombosis or other diseases.
17. Regression-based algorithm for bulk motion subtraction in optical coherence tomography angiography.
Camino, Acner; Jia, Yali; Liu, Gangjun; Wang, Jie; Huang, David
2017-06-01
We developed an algorithm to remove decorrelation noise due to bulk motion in optical coherence tomography angiography (OCTA) of the posterior eye. In this algorithm, OCTA B-frames were divided into segments within which the bulk motion velocity could be assumed to be constant. This velocity was recovered using linear regression of decorrelation versus the logarithm of reflectance in axial lines (A-lines) identified as bulk tissue by percentile analysis. The fitting parameters were used to calculate a reflectance-adjusted upper bound threshold for bulk motion decorrelation. Below this threshold, voxels are identified as non-flow tissue, their flow values are set to zeros. Above this threshold, the voxels are identified as flow voxels and bulk motion velocity is subtracted from each using a nonlinear decorrelation-velocity relationship previously established in laboratory flow phantoms. Compared to the simpler median-subtraction method, the regression-based bulk motion subtraction improved angiogram signal-to-noise ratio, contrast, vessel density repeatability, and bulk motion noise cleanup in the foveal avascular zone, while preserving the connectivity of the vascular networks in the angiogram.
18. Optimising Optimal Image Subtraction
Israel, H; Schuh, S; Israel, Holger; Hessman, Frederic V.; Schuh, Sonja
2006-01-01
Difference imaging is a technique for obtaining precise relative photometry of variable sources in crowded stellar fields and, as such, constitutes a crucial part of the data reduction pipeline in surveys for microlensing events or transiting extrasolar planets. The Optimal Image Subtraction (OIS) algorithm permits the accurate differencing of images by determining convolution kernels which, when applied to reference images of particularly good quality, provide excellent matches to the point-spread functions (PSF) in other images of the time series to be analysed. The convolution kernels are built as linear combinations of a set of basis functions, conventionally bivariate Gaussians modulated by polynomials. The kernel parameters must be supplied by the user and should ideally be matched to the PSF, pixel-sampling, and S/N of the data to be analysed. We have studied the outcome of the reduction as a function of the kernel parameters using our implementation of OIS within the TRIPP package. From the analysis o...
19. Pulse subtraction Doppler
Mahue, Veronique; Mari, Jean Martial; Eckersley, Robert J.; Caro, Colin G.; Tang, Meng-Xing
2010-01-01
Recent advances have demonstrated the feasibility of molecular imaging using targeted microbubbles and ultrasound. One technical challenge is to selectively detect attached bubbles from those freely flowing bubbles and surrounding tissue. Pulse Inversion Doppler is an imaging technique enabling the selective detection of both static and moving ultrasound contrast agents: linear scatterers generate a single band Doppler spectrum, while non-linear scatterers generate a double band spectrum, one being uniquely correlated with the presence of contrast agents and non-linear tissue signals. We demonstrate that similar spectrums, and thus the same discrimination, can be obtained through a Doppler implementation of Pulse Subtraction. This is achieved by reconstructing a virtual echo using the echo generated from a short pulse transmission. Moreover by subtracting from this virtual echo the one generated from a longer pulse transmission, it is possible to fully suppress the echo from linear scatterers, while for non-linear scatterers, a signal will remain, allowing classical agent detection. Simulations of a single moving microbubble and a moving linear scatterer subject to these pulses show that when the virtual echo and the long pulse echo are used to perform pulsed Doppler, the power Doppler spectrum allows separation of linear and non-linear moving scattering. Similar results are obtained on experimental data acquired on a flow containing either microbubble contrast agents or linear blood mimicking fluid. This new Doppler method constitutes an alternative to Pulse Inversion Doppler and preliminary results suggest that similar dual band spectrums could be obtained by the combination of any non-linear detection technique with Doppler demodulation.
20. Effectiveness of ProTaper Universal® and D-RaCe® retreatment files in the removal of root canal filling material: an in vitro study using digital subtraction radiography
Caroline Zanesco
2014-01-01
Full Text Available Aim: To compare the effectiveness of the ProTaper Universal ® Retreatment system, the D-Race ® NiTi system and Hedströem fi les for removal of fi lling material from curved root canals. Methodology: A total of 39 fi rst mandibular molars were selected and their mesiobuccal (MB canals were used for the study. Teeth were assigned to one of three identical groups (n = 13 per group according to removal technique: G1 – ProTaper Universal ® Retreatment (D1, D2, D3; G2 – D-RaCe ® (DR1, DR2; or G3 – Hedströem fi les (35, 30, 25, 20. In all groups, supplementary fi les were used for re-preparation. Digital subtraction radiography images were produced by superimposing the fi rst radiograph, taken after fi lling the canal, over the second, taking after removal of the fi lling, in buccolingual (BL and mesiodistal (MD projections. Quantitative data were analyzed using intraclass correlation coef fi cients and the Kruskal-Wallis and Friedman non-parametric tests (p ≤ 0.05. Results: Comparison of groups detected no differences in fi lling removal between teeth in the ProTaper Universal ® Retreatment, D-RaCe ® or Hedströem fi le groups for the cervical or mid thirds (for either MD or BL projections. In the apical third (MD projection, ProTaper Universal ® Retreatment produced the best results; and Hedströem fi les exhibited the worst results (MD projection. Intra-group comparisons showed that the cervical third was the cleanest and the apical third was the least well-cleaned, for the ProTaper Universal ® Retreatment and D-RaCe ® groups (MD projection, while less fi lling material was removed using Hedströem when the canals approached the apical third (MD and BL projections. Conclusions: Our fi ndings indicate that the ProTaper Universal ® Retreatment system is the best choice for endodontic fi lling material removal, combined with supplementary instrumentation to achieve better results in the apical third.
1. Background subtraction theory and practice
Elgammal, Ahmed
2014-01-01
Background subtraction is a widely used concept for detection of moving objects in videos. In the last two decades there has been a lot of development in designing algorithms for background subtraction, as well as wide use of these algorithms in various important applications, such as visual surveillance, sports video analysis, motion capture, etc. Various statistical approaches have been proposed to model scene backgrounds. The concept of background subtraction also has been extended to detect objects from videos captured from moving cameras. This book reviews the concept and practice of back
2. Smartphone as a Remote Touchpad to Facilitate Visualization of 3D Cerebral Angiograms during Aneurysm Surgery.
2017-09-01
Background During aneurysm surgery, neurosurgeons may need to look at the cerebral angiograms again to better orient themselves to the aneurysm and also the surrounding vascular anatomy. Simplification of the intraoperative imaging review and reduction of the time interval between the view under the microscope and the angiogram review can theoretically improve orientation. Objective To describe the use of a smartphone as a remote touchpad to simplify intraoperative visualization of three-dimensional (3D) cerebral angiograms and reduce the time interval between the view under the microscope and the angiogram review. Methods Anonymized 3D angiograms of the patients in Virtual Reality Modelling Language format are securely uploaded to sketchfab.com, accessible through smartphone Web browsers. A simple software has been developed and made available to facilitate the workflow. The smartphone is connected wirelessly to an external monitor using a Chromecast device and is used intraoperatively as a remote touchpad to view/rotate/zoom the 3D aneurysms angiograms on the external monitor. Results Implementation of the method is practical and helpful for the surgeon in certain cases. It also helps the operating staff, registrars, and students to orient themselves to the surgical anatomy. I present 10 of the uploaded angiograms published online. Conclusion The concept and method of using the smartphone as a remote touchpad to improve intraoperative visualization of 3D cerebral angiograms is described. The implementation is practical, using easily available hardware and software, in most neurosurgical centers worldwide. The method and concept have potential for further development. Georg Thieme Verlag KG Stuttgart · New York.
3. Developing a Model to Support Students in Solving Subtraction
Nila Mareta Murdiyani
2013-01-01
Full Text Available Subtraction has two meanings and each meaning leads to the differentstrategies. The meaning of “taking away something” suggests a directsubtraction, while the meaning of “determining the difference betweentwo numbers” is more likely to be modeled as indirect addition. Manyprior researches found that the second meaning and second strategy rarely appeared in the mathematical textbooks and teacher explanations, including in Indonesia. Therefore, this study was conducted to contribute to the development of a local instruction theory for subtraction by designing instructional activities that can facilitate first grade of primary school students to develop a model in solving two digit numbers subtraction. Consequently, design research was chosen as an appropriate approach for achieving the research aim and Realistic Mathematics Education (RME was used as a guide to design the lesson. This study involved 6 students in the pilot experiment, 31 students in the teaching experiment, and a first grade teacher of SDN 179 Palembang. The result of this study shows that the beads string could bridge students from the contextual problems (taking ginger candies and making grains bracelets to the use of the empty number line. It also shows that the empty number line could promote students to use different strategies (direct subtraction, indirect addition, and indirect subtraction in solving subtraction problems. Based on these findings, it is recommended to apply RME in the teaching learning process to make it more meaningful for students.
4. Developing a Model to Support Students in Solving Subtraction
Nila Mareta Murdiyani
2013-01-01
Full Text Available Subtraction has two meanings and each meaning leads to the different strategies. The meaning of “taking away something” suggests a direct subtraction, while the meaning of “determining the difference between two numbers” is more likely to be modeled as indirect addition. Many prior researches found that the second meaning and second strategy rarely appeared in the mathematical textbooks and teacher explanations, including in Indonesia. Therefore, this study was conducted to contribute to the development of a local instruction theory for subtraction by designing instructional activities that can facilitate first grade of primary school students to develop a model in solving two digit numbers subtraction. Consequently, design research was chosen as an appropriate approach for achieving the research aim and Realistic Mathematics Education (RME was used as a guide to design the lesson. This study involved 6 students in the pilot experiment, 31 students in the teaching experiment, and a first grade teacher of SDN 179 Palembang. The result of this study shows that the beads string could bridge students from the contextual problems (taking ginger candies and making grains bracelets to the use of the empty number line. It also shows that the empty number line could promote students to use different strategies (direct subtraction, indirect addition, and indirect subtraction in solving subtraction problems. Based on these findings, it is recommended to apply RME in the teaching learning process to make it more meaningful for students. Keywords: Subtraction, Design Research, Realistic Mathematics Education, The Beads String, The Empty Number Line DOI: http://dx.doi.org/10.22342/jme.4.1.567.95-112
5. Digital subtraktion
Mussmann, Bo Redder
2004-01-01
Digital subtraktion er en metode til at fjerne uønskede oplysninger i et røntgenbillede. Subtraktionsteknikken bruges primært i forbindelse med angiografi hvor man kun er interesseret i at se selve karret. Derfor er digital subtraktion i daglig tale synonymt med DSA eller DVI – hhv. Digital...... Subtraction Angiography eller Digital Vascular Imaging. Benævnelserne er to røntgenfirmaers navn for den samme teknik. Digital subtraktion kræver speciel software, samt at apparaturet kan eksponere i serier....
6. Application of preoperative systematic health education in digital subtraction angiography%术前系统性健康教育在数字减影全脑血管造影中的应用
马学英; 陈建伟; 宋淑霞; 袁桂敏; 宋立霞; 王青青
2012-01-01
目的:探讨术前系统性健康教育在数字减影全脑血管造影(DSA)中的应用效果.方法:将124例住院行DSA的患者随机分为观察组与对照组各62例.对照组按常规进行宣教,2 d内共进行3次.观察组成立由2名主管护师和2名护师组成的健康教育小组,制订系统性健康教育计划表和时间表,根据DSA术前、术中及术后的基础护理知识确定DSA前的教育内容,并制成小册子和图片,根据患者的身心状况,面对面地对患者和家属实施个体化的心理护理和疾病健康指导,2 d内共3次,并对主要内容和注意事项进行提问,直到患者和家属掌握为止.结果:与对照组同期比较,观察组术前教育后和术后SAS评分明显降低(P＜0.01),且观察组术后并发症明显少于对照组(P＜0.01,P＜0.05).结论:对DSA患者术前进行系统性健康教育可明显改善其心理状态,提高其治疗依从性,减少术后并发症.%Objective: To investigate the application effect of preoperative systematic health education in digital subtraction angiography ( DSA ). Methods: 124 hospitalized patients who would undergo DSA were randomly divided into an observation group and a control group ( 62 cases in each group ). The routine health education was conducted for 3 times within 2 days in the control group; the preoperative systematic health education program and schedule were formulated by the group composed of 2 nurses in - charge and 2 nurses, and the contents of preoperative health education were compiled according to the basic nursing knowledge of DSA in preoperative, intraoperative and postoperative period. The individualized psychological care and health guidance were given to the patients and their families 3 times in 2 days according to the patients physical and mental conditions by using booklet and pictures. Results: SAS score significantly decreased after health education and after surgery in the observation group compared with control
7. Digitization
Finnemann, Niels Ole
2014-01-01
Processes of digitization have for years represented a major trend in the developments of modern society but have only recently been related to processes of mediatization. The purpose of this article is to look into the relation between the concepts of mediatization and digitization and to clarify...... what a concept of digital media might add to the understanding of processes of mediatization and what the concept of mediatization might add to the understanding of digital media. It is argued that digital media open an array of new trajectories in human communication, trajectories which were...... not anticipated in previous conceptualizations of media and mediatization. If digital media are to be included, the concept of mediatization has to be revised and new parameters are to be built into the concept of media. At the same time it is argued that the concept of mediatization still provides a variety...
8. Color Addition and Subtraction Apps
Ruiz, Frances; Ruiz, Michael J.
2015-10-01
Color addition and subtraction apps in HTML5 have been developed for students as an online hands-on experience so that they can more easily master principles introduced through traditional classroom demonstrations. The evolution of the additive RGB color model is traced through the early IBM color adapters so that students can proceed step by step in understanding mathematical representations of RGB color. Finally, color addition and subtraction are presented for the X11 colors from web design to illustrate yet another real-life application of color mixing.
9. Digital subtraction angiography of predominant artery feeding pancreatic body and tail%胰体尾优势供血动脉的数字减影血管造影
吴志贤; 蔡锦全; 杨熙章; 廖联明; 罗芳; 杨利; 林宇宁; 谭建明
2013-01-01
Objective To investigate the anatomical characteristics of predominant artery feeding pancreatic body and tail (PBT). Methods One hundred and eight patients with diabetes (61 males and 47 females) underwent digital subtraction angiography ( DSA). Selective DSA of the celiac trunk, gastroduodenal artery, and superior mesenteric artery were performed to localize the potential predominant feeding artery of the PBT. The feeding artery was catheterized and DSA was performed. All images were documented for later analysis. Results The feeding arteries for the PBT included the sole dorsal pancreatic artery ( DPA, 58. 3% ) , sole great pancreatic artery (GPA, 13. 9% ) , both DPA and GPA (11. 1% ) , and transverse pancreatic artery (TPA, 14.8%). The DPA originated from the first segment of the splenic artery (52.0%), common hepatic artery (21.3%), or superior mesenteric artery (24.0%). The GPA was mostly from the middle segment of the splenic artery (96. 3% ) The TPA was from either the gastroduodenal artery (68. 8% ) or the pancreaticoduodenal artery (31.2% ). Conclusion The origins and identities of the predominant artery in the PBT are variable, which require comprehensive study before interventional therapy for diabetic patients.%目的 采用数字减影血管造影(DSA)方法,研究糖尿病患者胰体尾优势供血动脉的解剖特点,为临床胰腺介入治疗提供血管解剖依据.方法 糖尿病患者108例,男61例,女47例,于介入治疗手术室行胰体尾动脉造影.第一阶段进行腹腔干、胃十二指肠动脉、肠系膜上动脉造影,初步定位胰尾体部优势供血动脉,之后将导管直接置入目标动脉,行DSA,观察胰体尾显影情况.如置入失败,则采用脾动脉远端球囊堵塞近端造影的方法,对胰体尾进行显影.保存介入影像进行分析.结果 造影显示,胰体尾优势供血动脉分别为胰背动脉(58.3％,63/108)、胰大动脉(13.9％,15/108)、胰背动脉联合胰大动脉(11.1％,12/108)
10. Behavior Subtraction applied to radar
Rossum, W.L. van; Caro Cuenca, M.
2014-01-01
An algorithm developed for optical images has been applied to radar data. The algorithm, Behavior Subtraction, is based on capturing the dynamics of a scene and detecting anomalous behavior. The radar application is the detection of small surface targets at sea. The sea surface yields the expected s
11. Color Addition and Subtraction Apps
Ruiz, Frances; Ruiz, Michael J.
2015-01-01
Color addition and subtraction apps in HTML5 have been developed for students as an online hands-on experience so that they can more easily master principles introduced through traditional classroom demonstrations. The evolution of the additive RGB color model is traced through the early IBM color adapters so that students can proceed step by step…
12. Color Addition and Subtraction Apps
Ruiz, Frances; Ruiz, Michael J.
2015-01-01
Color addition and subtraction apps in HTML5 have been developed for students as an online hands-on experience so that they can more easily master principles introduced through traditional classroom demonstrations. The evolution of the additive RGB color model is traced through the early IBM color adapters so that students can proceed step by step…
13. PCA-derived respiratory motion surrogates from X-ray angiograms for percutaneous coronary interventions
H. Ma (Hua); G. Dibildox (Gerardo); C. Schultz (Carl); E.S. Regar (Eveline); T.W. van Walsum (Theo)
2015-01-01
textabstractPurpose: Intraoperative coronary motion modeling with motion surrogates enables prospective motion prediction in X-ray angiograms (XA) for percutaneous coronary interventions. The motion of coronary arteries is mainly affected by patients breathing and heartbeat. Purpose of our work is t
14. Coronary artery segmentation in X-ray angiogram using Gabor filters and differential evolution
Cervantes S, F.; Hernandez A, A.; Cruz A, I. [Centro de Investigacion en Matematicas, A. C., Jalisco s/n, Col. Valenciana, 36240 Guanajuato, Gto. (Mexico); Solorio M, S. [IMSS, Unidad de Investigacion, UMAE Hospital de Especialidades No. 1 del Centro Medico Nacional del Bajio, 37260 Leon, Guanajuato (Mexico); Cordova F, T. [Universidad de Guanajuato, Departamento de Ingenieria Fisica, 37150 Leon, Guanajuato (Mexico); Avina C, J. G., E-mail: [email protected] [Universidad de Guanajuato, Departamento de Electronica, 36885 Salamanca, Guanajuato (Mexico)
2016-10-15
Segmentation of coronary arteries in X-ray angiograms represents an essential task for computer-aided diagnosis, since it can help cardiologists in diagnosing and monitoring vascular abnormalities. Due to the main disadvantages of the X-ray angiograms are the nonuniform illumination, and the weak contrast between blood vessels and image background, different vessel enhancement methods have been introduced. In this paper, a novel method for blood vessel enhancement based on Gabor filters tuned using the optimization strategy of Differential evolution (De) is proposed. Because the Gabor filters are governed by three different parameters, the optimal selection of those parameters is highly desirable in order to maximize the vessel detection rate while reducing the computational cost of the training stage. To obtain the optimal set of parameters for the Gabor filters, the area (Az) under the receiver operating characteristic curve is used as objective function. In the experimental results, the proposed method obtained the highest detection performance with Az = 0.956 using a test set of 60 angiograms, and Az = 0.934 with a training set of 20 angiograms compared with different state-of-the-art vessel detection methods. In addition, the experimental results in terms of computational time have also shown that the proposed method can be highly suitable for clinical decision support. (Author)
15. Myocardial ischaemia with a normal coronary angiogram due to the primary antiphospholipid syndrome
de Vries, PAM; van der Sluis, A; van der Horst, JCC; van Veldhuisen, DJ
2002-01-01
In this case report, we describe a 33-year-old woman with a history of two unprovoked thrombo-embolic events presenting with acute myocardial ischaemia. She had a normal coronary angiogram (CAG). The diagnosis primary antiphospholipid syndrome (APS), an acquired hypercoagulability disorder, was esta
16. 胸部双能量减影摄影对气胸的诊断价值%The value of dual-energy subtraction with direct digital radiography in diagnosis of pneumothorax
赵钊; 陈立鹏; 王秀河; 黄力; 刘文华
2012-01-01
目的 探讨双能量减影摄片技术对气胸的诊断价值.方法 收集在本院行双能量胸部摄影,经CT检查证实为气胸的42例患者,由1位高年资放射科医师及1位高年资胸外科医生共同阅片,对其标准数字化摄影(DR)图像与双能量数字减影(DES)软组织图像进行分析,评价两者对气胸的显示情况.结果 对于大、中量气胸(13例,肺压缩≥20%),标准DR图像及DES软组织图像均能清楚显示(100%),但对于少量气胸(肺压缩＜20%),尤其肺压缩边缘与肋骨、锁骨、肩胛骨重叠者,DES软组织图像比标准DR图像检出率更高,对肺压缩边缘的显示更清晰,差异有统计学意义.结论 双能量减影摄片技术能提高气胸的诊断率,降低漏诊率,是对DR图像诊断气胸的有效补充.%Objective To evaluate the ability of DR dual-energy subtraction(DES) in diagnosing pneumothorax.Methods 42 patients with pneumothorax confirmed by CT underwent dual-energy subtraction radiography of the chest in our hospital.The chest films were analysed by one senior radiologist and one surgeon.The detection of pneumothorax was evaluated with both DR and DES.Results The magnanimous or moderately pneumothorax (13 cases,pulmonary compression≥20% (could be detected by DR images and DES soft tissue images (100%) ,but for slight pneumothorax (pulmonary compression<20% ) , especially when pneumothorax line overlap with costa,clavicle and scapula,DES soft tissue images could detect it more sensitively than regular DR images,and the pneumothorax lines were showed more clearly, there was statistical difference between these two images.Conclusion Dual-energy subtraction technique is superior to regular DR images in showing the pneumothorax line,so it can improve the diagnosis of pneumothorax and reduce the rate of misdiagnosis.Dual energy subtraction images can act as an effective complement for the original DR images in diagnosing pneumothorax.
17. Dual-energy subtraction radiography of the breast
Asaga, Taro; Masuzawa, Chihiro; Kawahara, Satoru; Motohashi, Hisahiko; Okamoto, Takashi; Tamura, Nobuo
1988-06-01
18. Automated computer evaluation and optimization of image compression of x-ray coronary angiograms for signal known exactly detection tasks
Eckstein, Miguel P.; Bartroff, Jay L.; Abbey, Craig K.; Whiting, James S.; Bochud, Francois O.
2003-03-01
We compared the ability of three model observers (nonprewhitening matched filter with an eye filter, Hotelling and channelized Hotelling) in predicting the effect of JPEG and wavelet-Crewcode image compression on human visual detection of a simulated lesion in single frame digital x-ray coronary angiograms. All three model observers predicted the JPEG superiority present in human performance, although the nonprewhitening matched filter with an eye filter (NPWE) and the channelized Hotelling models were better predictors than the Hotelling model. The commonly used root mean square error and related peak signal to noise ratio metrics incorrectly predicted a JPEG inferiority. A particular image discrimination/perceptual difference model correctly predicted a JPEG advantage at low compression ratios but incorrectly predicted a JPEG inferiority at high compression ratios. In the second part of the paper, the NPWE model was used to perform automated simulated annealing optimization of the quantization matrix of the JPEG algorithm at 25:1 compression ratio. A subsequent psychophysical study resulted in improved human detection performance for images compressed with the NPWE optimized quantization matrix over the JPEG default quantization matrix. Together, our results show how model observers can be successfully used to perform automated evaluation and optimization of diagnostic performance in clinically relevant visual tasks using real anatomic backgrounds.
19. Value of Subtraction in Fat-Saturated Three-Dimensional Contrast-Enhanced Magnetic Resonance Angiography of the Hemodialysis Fistula
Takahashi, N.; Sato, M.; Niitsu, M.; Saida, Y. [Univ. of Tsukuba Hospital, Ibaraki (Japan). Dept. of Radiology
2004-10-01
Purpose: To evaluate image subtraction in a three-dimensional contrast-enhanced magnetic resonance angiography (3D CE-MRA) using fat suppression for the hemodialysis fistula. Material and Methods: Fifteen patients suffering from hemodialysis fistula dysfunction were imaged with 3D CE-MRA using fat suppression and digital subtraction angiography (DSA). Non-subtracted and subtracted MRA images using maximum intensity projection (MIP) were constructed and the validity of the MRA interpretations of the degree of vascular stenoses was evaluated using DSA as the standard of reference. Image quality was assessed using qualitative analysis (vessel contrast) and quantitative analysis (contrast-to-noise ratio (CNR) of the vessel versus the background). Results: In the vessels with stenosis of 50% or greater, the sensitivity and specificity of the non-subtracted MRA were 89.5% and 81.8%, respectively, and of the subtracted MRA 89.5% and 86.4%, respectively. There was no significant difference in the detectability of stenoses between either MRA. The vessel contrast of the anterior interosseous artery and the CNR of the anterior interosseous artery versus the background on the subtracted MRA were significantly superior to those on the non-subtracted MRA. With regard to the radial artery and cephalic vein, there was no significant difference in the vessel contrast and CNR between either MRA. Conclusion: Both subtracted and non-subtracted MRA techniques are useful in detecting hemodialysis fistula dysfunction.
20. [Acute epidural hematoma with extravasation on cerebral angiogram in an infant (author's transl)].
Oseki, J; Oana, K; Kobayashi, T; Kawada, Y; Kanaya, H
1977-03-01
The authors recently operated on a boy four years of age with acute epidural hematoma showing an extravasation on the cerebral angiogram. The hematoma (hematoma volume 125 ml) was evacuated 7 hours after the head injury. The postoperative course was quite uneventful, and he was discharged a month after surgery without any neurologic deficits. The authors reviewed the literature and found 4 cases of acute epidural hematoma with extravasations in infants and children. In all cases the operative results were good. The age incidence and frequency of occurence overall for acute epidural hematomas, extravasations on cerebral angiograms and their mechanism, and the length of time from injury to operation were also discussed. It should be emphasized that, for acute epidural hematoma in infants and children, the early diagnosis and early surgery are essential to save the patients.
1. The coronary computed tomography angiogram: from the basics to advanced interpretation
Tiong Kiam ONG; Stephan Achenbach
2006-01-01
@@ Introduction According to the WHO's World Health Report 2003, 1cardiovascular disease was responsible for 16.7 million deaths annually. As a result, it is now the leading cause of death in developed countries and in many developing countries. Detecting and preventing the progression of coronary artery disease is the target of many pharmaceutical, technological and other scientific programs today. Presently, the main diagnostic tool for evaluating coronary arteries is thc conventional coronary angiogram (CCA).
2. Assessment of Potential Live Kidney Donors and Computed Tomographic Renal Angiograms at Christchurch Hospital
Thamer Alsulaiman
2016-01-01
Full Text Available Aims. To examine the outcome of potential live kidney donors (PLKD assessment program at Christchurch Hospital and, also, to review findings of Computed Tomographic (CT renal angiograms that led to exclusion in the surgical assessment. Methods. Clinical data was obtained from the database of kidney transplants, Proton. Radiological investigations were reviewed using the hospital database, Éclair. The transplant coordinator was interviewed to clarify information about PLKD who did not proceed to surgery, and a consultant radiologist was interviewed to explain unfavorable findings on CT renal angiograms. Results. 162 PLKD were identified during the period January 04–June 08. Of those, 65 (40% proceeded to have nephrectomy, 15 were accepted and planned to proceed to surgery, 13 were awaiting further assessment, and 69 (42.5% did not proceed to nephrectomy. Of the 162 PLKD, 142 (88% were directed donors. The proportion of altruistic PLKD who opted out was significantly higher than that of directed PLKD (45% versus 7%, P=0.00004. Conclusions. This audit demonstrated a positive experience of live kidney donation at Christchurch Hospital. CT renal angiogram can potentially detect incidental or controversial pathologies in the kidney and the surrounding structures. Altruistic donation remains controversial with higher rates of opting out.
3. Assessment of Potential Live Kidney Donors and Computed Tomographic Renal Angiograms at Christchurch Hospital.
Alsulaiman, Thamer; Mark, Stephen; Armstrong, Sarah; McGregor, David
2016-01-01
Aims. To examine the outcome of potential live kidney donors (PLKD) assessment program at Christchurch Hospital and, also, to review findings of Computed Tomographic (CT) renal angiograms that led to exclusion in the surgical assessment. Methods. Clinical data was obtained from the database of kidney transplants, Proton. Radiological investigations were reviewed using the hospital database, Éclair. The transplant coordinator was interviewed to clarify information about PLKD who did not proceed to surgery, and a consultant radiologist was interviewed to explain unfavorable findings on CT renal angiograms. Results. 162 PLKD were identified during the period January 04-June 08. Of those, 65 (40%) proceeded to have nephrectomy, 15 were accepted and planned to proceed to surgery, 13 were awaiting further assessment, and 69 (42.5%) did not proceed to nephrectomy. Of the 162 PLKD, 142 (88%) were directed donors. The proportion of altruistic PLKD who opted out was significantly higher than that of directed PLKD (45% versus 7%, P = 0.00004). Conclusions. This audit demonstrated a positive experience of live kidney donation at Christchurch Hospital. CT renal angiogram can potentially detect incidental or controversial pathologies in the kidney and the surrounding structures. Altruistic donation remains controversial with higher rates of opting out.
4. Eigenspectrum Noise Subtraction Methods in Lattice QCD
Guerrero, Victor; Wilcox, Walter
2010-01-01
We propose a new noise subtraction method, which we call "eigenspectrum subtraction", which uses low eigenmode information to suppress statistical noise at low quark mass. This is useful for lattice calculations involving disconnected loops or all-to-all propagators. It has significant advantages over perturbative subtraction methods. We compare unsubtracted, eigenspectrum and perturbative error bar results for the scalar operator on a small Wilson QCD matrix.
5. New Noise Subtraction Methods in Lattice QCD
Baral, Suman; Morgan, Ronald B
2016-01-01
Noise subtraction techniques can help reduce the statistical uncertainty in the extraction of hard to detect signals. We describe new noise subtraction methods in Lattice QCD which apply to disconnected diagram evaluations. Some of the noise suppression techniques include polynomial quark matrix methods, eigenspectrum deflation methods, and combination methods. Our most promising technique combines polynomial and Hermitian deflation subtraction methods. The overall goal is to improve the efficiency of Lattice QCD noise method algorithms.
6. Clinical values of hemodynamics assessment by parametric color coding of digital subtraction angiography before and after endovascular therapy for critical limb ischaemia%彩色编码血流成像在严重下肢动脉缺血腔内治疗前后循环变化的评估价值
苏浩波; 楼文胜; 顾建平
2015-01-01
Objective To investigate the feasibility of parametric color coding of digital subtraction angiography(Syngo iFlow)for hemodynamics assessment in patients with critical limb ischemia in pre-and post-endovascular therapy.To explore the correlation between Syngo iFlow and the conventional techniques.Methods from January 2013 to December 2014,Clinical data of 21 patients with TASC Ⅱ type B and type C femoropopliteal arteriosclerotic occlusive disease who were treated by percutaneous transluminal angioplasty and/or primary stent implantation in Nanjing first hospital were analyzed retrospectively.Of these patients there were 10 males and 11 females with an average age of (72 ±6) years (range from 58-85 years).The treatment efficacy was assessed by the variation of a series of clinical symptoms indexes (such as pain score,cold sensation score and intermittent claudication score),ankle braehial index (ABI) and transcutaneous oxygen pressure (TcPO2).Angiography was performed with the same protocol before and after treatment and parametric color coding of digital subtraction angiography was created by Syngo iFlow software on a dedicated workstation.The time to peak (TTP) of artery and tissue perfusion selected at the same regions of foot and ankle were measured and analyzed to evaluate the improvement of microcirculation and hemodynamics of the ischemic limb.The correlations between Syngo iFlow and the traditional clinical evaluation methods were explored using the Spearman rank correlation test.Results All patients (21 limbs) underwent successful endovaseular therapy.The mean pain score,cold sensation score,intermittent claudication score,ABI and TcPO2 before treatment were(0.48 ± 0.68),(2.71 ± 0.72),(2.86 ± 0.85),ABI (0.33 ± 0.07),TcPO2 (26.83 ± 3.41) mmHg.While 1 week after treatment all above indicators were (2.57 ± 0.93),(0.33 ± 0.48),(0.90 ± 0.54),(0.69 ± 0.11),TcPO2 (53.75 ± 3.60) mmHg respectively.There were significant statistical differences between
7. Supplementary angiography when lumbar angiograms fail to demonstrate the vessels to the leg
Noer, Ivan; Praestholm, J; Tønnesen, K H
1981-01-01
The peripheral run-off arteries were insufficiently visualized due to occlusions in the aorto-iliac segments in studies of 10 patients (15 legs) in 183 consecutive aorto-femoral angiograms. Guided by a combination of the Doppler technique and fluoroscopy, the non-opacified and pulseless common...... was considered as representing non-reconstructable lesions by our vascular surgeons. The findings in the present study showed that in these patients surgical reconstruction of only the aorto-iliac segments will suffice to save the limb from amputation....
8. A Case of Cardiac Cephalalgia Showing Reversible Coronary Vasospasm on Coronary Angiogram
Yang, YoungSoon; Jin, Dong Gyu; Jang, Il Mi; Jang, YoungHee; Na, Hae Ri; Kim, SanYun
2010-01-01
Background Under certain conditions, exertional headaches may reflect coronary ischemia. Case Report A 44-year-old woman developed intermittent exercise-induced headaches with chest tightness over a period of 10 months. Cardiac catheterization followed by acetylcholine provocation demonstrated a right coronary artery spasm with chest tightness, headache, and ischemic effect of continuous electrocardiography changes. The patient's headache disappeared following intra-arterial nitroglycerine injection. Conclusions A coronary angiogram with provocation study revealed variant angina and cardiac cephalalgia, as per the International Classification of Headache Disorders (code 10.6). We report herein a patient with cardiac cephalalgia that manifested as reversible coronary vasospasm following an acetylcholine provocation test. PMID:20607049
9. Helping Students to Connect Subtraction Strategies Improves Mathematical Reasoning for Students and Teachers
Sci, Eve
2011-01-01
After administering an end of unit assessment written by the school's math program, teachers of three second grade classes in a New York City school noticed a majority of the students had not demonstrated mastery of subtracting two, two-digit numbers. The teachers worked with the school's math coach to implement an instructional unit that required…
10. Device and methods for "gold standard" registration of clinical 3D and 2D cerebral angiograms
2015-03-01
Translation of any novel and existing 3D-2D image registration methods into clinical image-guidance systems is limited due to lack of their objective validation on clinical image datasets. The main reason is that, besides the calibration of the 2D imaging system, a reference or "gold standard" registration is very difficult to obtain on clinical image datasets. In the context of cerebral endovascular image-guided interventions (EIGIs), we present a calibration device in the form of a headband with integrated fiducial markers and, secondly, propose an automated pipeline comprising 3D and 2D image processing, analysis and annotation steps, the result of which is a retrospective calibration of the 2D imaging system and an optimal, i.e., "gold standard" registration of 3D and 2D images. The device and methods were used to create the "gold standard" on 15 datasets of 3D and 2D cerebral angiograms, whereas each dataset was acquired on a patient undergoing EIGI for either aneurysm coiling or embolization of arteriovenous malformation. The use of the device integrated seamlessly in the clinical workflow of EIGI. While the automated pipeline eliminated all manual input or interactive image processing, analysis or annotation. In this way, the time to obtain the "gold standard" was reduced from 30 to less than one minute and the "gold standard" of 3D-2D registration on all 15 datasets of cerebral angiograms was obtained with a sub-0.1 mm accuracy.
11. Adaptive Ridge Point Refinement for Seeds Detection in X-Ray Coronary Angiogram
Ruoxiu Xiao
2015-01-01
Full Text Available Seed point is prerequired condition for tracking based method for extracting centerline or vascular structures from the angiogram. In this paper, a novel seed point detection method for coronary artery segmentation is proposed. Vessels on the image are first enhanced according to the distribution of Hessian eigenvalue in multiscale space; consequently, centerlines of tubular vessels are also enhanced. Ridge point is extracted as candidate seed point, which is then refined according to its mathematical definition. The theoretical feasibility of this method is also proven. Finally, all the detected ridge points are checked using a self-adaptive threshold to improve the robustness of results. Clinical angiograms are used to evaluate the performance of the proposed algorithm, and the results show that the proposed algorithm can detect a large set of true seed points located on most branches of vessels. Compared with traditional seed point detection algorithms, the proposed method can detect a larger number of seed points with higher precision. Considering that the proposed method can achieve accurate seed detection without any human interaction, it can be utilized for several clinical applications, such as vessel segmentation, centerline extraction, and topological identification.
12. Segmentation of Coronary Angiograms Using Gabor Filters and Boltzmann Univariate Marginal Distribution Algorithm
Cervantes-Sanchez, Fernando; Hernandez-Aguirre, Arturo; Solorio-Meza, Sergio; Ornelas-Rodriguez, Manuel; Torres-Cisneros, Miguel
2016-01-01
This paper presents a novel method for improving the training step of the single-scale Gabor filters by using the Boltzmann univariate marginal distribution algorithm (BUMDA) in X-ray angiograms. Since the single-scale Gabor filters (SSG) are governed by three parameters, the optimal selection of the SSG parameters is highly desirable in order to maximize the detection performance of coronary arteries while reducing the computational time. To obtain the best set of parameters for the SSG, the area (Az) under the receiver operating characteristic curve is used as fitness function. Moreover, to classify vessel and nonvessel pixels from the Gabor filter response, the interclass variance thresholding method has been adopted. The experimental results using the proposed method obtained the highest detection rate with Az = 0.9502 over a training set of 40 images and Az = 0.9583 with a test set of 40 images. In addition, the experimental results of vessel segmentation provided an accuracy of 0.944 with the test set of angiograms. PMID:27738422
13. Segmentation of Coronary Angiograms Using Gabor Filters and Boltzmann Univariate Marginal Distribution Algorithm
Fernando Cervantes-Sanchez
2016-01-01
Full Text Available This paper presents a novel method for improving the training step of the single-scale Gabor filters by using the Boltzmann univariate marginal distribution algorithm (BUMDA in X-ray angiograms. Since the single-scale Gabor filters (SSG are governed by three parameters, the optimal selection of the SSG parameters is highly desirable in order to maximize the detection performance of coronary arteries while reducing the computational time. To obtain the best set of parameters for the SSG, the area (Az under the receiver operating characteristic curve is used as fitness function. Moreover, to classify vessel and nonvessel pixels from the Gabor filter response, the interclass variance thresholding method has been adopted. The experimental results using the proposed method obtained the highest detection rate with Az=0.9502 over a training set of 40 images and Az=0.9583 with a test set of 40 images. In addition, the experimental results of vessel segmentation provided an accuracy of 0.944 with the test set of angiograms.
14. Digital Artery Occlusion Secondary to Plastic Shopping Bag Trauma
Joy, R; Isaacs, JL; McCarthy, RJ
2007-01-01
Upper limb digital arterial occlusion is uncommon. We present the case of a 47-year-old man with an ischaemic right middle finger (dominant hand) due to trauma from carrying a heavy plastic shopping bag. Duplex scanning revealed no proximal source of emboli. An angiogram demonstrated occlusions in the medial and lateral digital arteries of the middle digit at the level of the proximal phalanx. Treatment with heparin and warfarin resulted in complete resolution of symptoms. PMID:18201465
15. Digital artery occlusion secondary to plastic shopping bag trauma.
Joy, R; Isaacs, J L; McCarthy, R J
2007-09-01
Upper limb digital arterial occlusion is uncommon. We present the case of a 47-year-old man with an ischaemic right middle finger (dominant hand) due to trauma from carrying a heavy plastic shopping bag. Duplex scanning revealed no proximal source of emboli. An angiogram demonstrated occlusions in the medial and lateral digital arteries of the middle digit at the level of the proximal phalanx. Treatment with heparin and warfarin resulted in complete resolution of symptoms.
16. Polynomial Subtraction Method for Disconnected Quark Loops
Liu, Quan; Morgan, Ron
2014-01-01
The polynomial subtraction method, a new numerical approach for reducing the noise variance of Lattice QCD disconnected matrix elements calculation, is introduced in this paper. We use the MinRes polynomial expansion of the QCD matrix as the approximation to the matrix inverse and get a significant reduction in the variance calculation. We compare our results with that of the perturbative subtraction and find that the new strategy yields a faster decrease in variance which increases with quark mass.
17. A Mathematical Model for Suppression Subtractive Hybridization
2002-01-01
Suppression subtractive hybridization (SSH) is frequently used to unearth differentially expressed genes on a whole-genome scale. Its versatility is based on combining cDNA library subtraction and normalization, which allows the isolation of sequences of varying degrees of abundance and differential expression. SSH is a complex process with many adjustable parameters that affect the outcome of gene isolation.We present a mathematical model of SSH based on DNA hybridization kinetics for assess...
18. FLAIR vascular hyperintensities and dynamic 4D angiograms for the estimation of collateral blood flow in posterior circulation occlusion
Foerster, Alex; Wenz, Holger; Kerl, Hans Ulrich; Al-Zghloul, Mansour; Habich, Sonia; Groden, Christoph [University of Heidelberg, Department of Neuroradiology, Universitaetsmedizin Mannheim, Mannheim (Germany)
2014-09-15
The objectives of this paper are to assess collateral blood flow in posterior circulation occlusion by MRI-based approaches (fluid-attenuated inversion recovery (FLAIR) vascular hyperintensities (FVHs), collateralization on dynamic 4D angiograms) and investigate its relation to ischemic lesion size and growth. In 28 patients with posterior cerebral artery (PCA) and 10 patients with basilar artery (BA) occlusion, MRI findings were analyzed, with emphasis on distal FVH and collateralization on dynamic 4D angiograms. In PCA occlusion, distal FVH was observed in 18/29 (62.1 %), in BA occlusion, in 8/10 (80 %) cases. Collateralization on dynamic 4D angiograms was graded 1 in 8 (27.6 %) patients, 2 in 1 (3.4 %) patient, 3 in 12 (41.4 %) patients, and 4 in 8 (27.6 %) patients with PCA occlusion and 0 in 1 (10 %) patient, 2 in 3 (30 %) patients, 3 in 1 (10 %) patient, and 4 in 5 (50 %) patients with BA occlusion. FVH grade showed neither correlation with initial or follow-up diffusion-weighted image (DWI) lesion size nor DWI-perfusion-weighted imaging (PWI) mismatch ratio. Collateralization on dynamic 4D angiograms correlated inversely with initial DWI lesion size and moderately with the DWI-(PWI) mismatch ratio. The combination of distal FVH and collateralization grade on dynamic 4D angiograms correlated inversely with initial as well as follow-up DWI lesion size and highly with the DWI-PWI mismatch ratio. In posterior circulation occlusion, FVH is a frequent finding, but its prognostic value is limited. Dynamic 4D angiograms are advantageous to examine and graduate collateral blood flow. The combination of both parameters results in an improved characterization of collateral blood flow and might have prognostic relevance. (orig.)
19. Assessing Intra-arterial Complications of Planning and Treatment Angiograms for Y-90 Radioembolization.
Ahmed, Osman; Patel, Mikin V; Masrani, Abdulrahman; Chong, Bradford; Osman, Mohammed; Tasse, Jordan; Soni, Jayesh; Turba, Ulku Cenk; Arslan, Bulent
2017-05-01
To report hepatic arterial-related complications encountered during planning and treatment angiograms for radioembolization and understand any potential-associated risk factors. 518 mapping or treatment angiograms for 180 patients with primary or metastatic disease to the liver treated by Yttrium-90 radioembolization between 2/2010 and 12/2015 were retrospectively reviewed. Intra-procedural complications were recorded per SIR guidelines. Patient demographics, indication for treatment, prior exposure to chemotherapeutic agents, operator experience, and disease burden were reviewed. Technical variables including type of radioembolic (glass vs. resin microspheres), indication for angiography (mapping vs. treatment), variant anatomy, and attempts at coil embolization were also assessed. Thirteen (13/518, 2.5%) arterial-related complications occurred in 13 patients. All but two complications resulted during transcatheter coil embolization to prevent non-target embolization. Complications included coil migration (n = 6), arterial dissection (n = 2), focal vessel perforation (n = 2), arterial thrombus (n = 2), and vasospasm prohibiting further arterial sub-selection (n = 1). Transarterial coiling was identified as a significant risk factor of complications on both univariate and multivariate regression analysis (odds ratio 7.8, P = 0.004). Usage of resin microspheres was also a significant risk factor (odds ratio 9.5, P = 0.042). No other technical parameters or pre-procedural variables were significant after adjusting for confounding on multivariate analysis (P > 0.05). Intra-procedural hepatic arterial complications encountered during radioembolization were infrequent but occurred mainly during coil embolization to prevent non-target delivery to extra-hepatic arteries.
20. Enhanced image reconstruction of three-dimensional fluorescent assays by subtractive structured-light illumination microscopy.
Choi, Jong-ryul; Kim, Donghyun
2012-10-01
We investigate improved image reconstruction of structured light illumination for high-resolution imaging of three-dimensional (3D) cell-based assays. For proof of concept, an in situ fluorescence optical detection system was built with a digital micromirror device as a spatial light modulator, for which phase and tilting angle in a grid pattern were varied to implement specific image reconstruction schemes. Subtractive reconstruction algorithms based on structured light illumination were used to acquire images of fluorescent microbeads deposited as a two-dimensional monolayer or in 3D alginate matrix. We have confirmed that an optical subtraction algorithm improves axial and lateral resolution by effectively removing out-of-focus fluorescence. The results suggest that subtractive image reconstruction can be useful for structured illumination microscopy of broad types of cell-based assays with high image resolution.
1. The Spectrum of Static Subtracted Geometries
2016-01-01
Subtracted geometries are black hole solutions of the four dimensional STU model with rather interesting ties to asymptotically flat black holes. In addition, a peculiar feature is that the solutions to the Klein-Gordon equation on this subtracted background can be organized according to representations of the conformal group $SO(2,2)$. We test if this behavior persists for the linearized fluctuations of gravitational and matter fields on static, electrically charged backgrounds of this kind. We find that there is a subsector of the modes that do display conformal symmetry, while some modes do not. We also discuss two different effective actions that describe these subtracted geometries and how the spectrum of quasinormal modes is dramatically different depending upon the action used.
2. Subtraction Radiographic Assessment of Underlying Dentin After Partial Carious Dentin Removal in Primary Teeth.
Phonghanyudh, Araya; Ruangdit, Chayathorn; Pornprasertsuk-D Amrongsri, Suchaya; Phanthumvanit, Prathip
2017-09-21
To assess the one-year outcome of glass-ionomer cement (GIC) restorations with partial carious dentin removal in primary molars using digital subtraction radiographs. Children ages 6-8 years were recruited. Forty-nine primary molars with deep carious lesions were studied. The carious dentin was removed at the dentoenamel junction (DEJ) and restored with GIC. Digital radiographs were taken immediately after restoration, and at 6 and 12 months after restoration. The sets of digital radiographs were subtracted and analysed using Image-Pro Plus software. At the 12-month follow-up, 38 of the original 49 primary molars were analysed. No postoperative pain or signs of pulp pathology were reported. 76% and 87% of molars showed an increase in density of the studied areas compared to control areas at 6- and 12- month follow-ups, respectively. The density of digital subtraction radiographs increased to 5.3 and 8.2 at 6 and 12 months from baseline, respectively. The mean density of the areas under restoration at 6 months and 12 months was statistically significantly higher than at baseline (paired t-test; p carious dentin removal in primary molars showed a high potential for dentin remineralisation after 1 year.
3. Probabilistic Model-Based Background Subtraction
Krüger, Volker; Andersen, Jakob; Prehn, Thomas
2005-01-01
manner. Bayesian propagation over time is used for proper model selection and tracking during model-based background subtraction. Bayes propagation is attractive in our application as it allows to deal with uncertainties during tracking. We have tested our approach on suitable outdoor video data....... is the correlation between pixels. In this paper we introduce a model-based background subtraction approach which facilitates prior knowledge of pixel correlations for clearer and better results. Model knowledge is being learned from good training video data, the data is stored for fast access in a hierarchical...
4. Construction of Differential-Methylation Subtractive Library
Wei Hu
2014-01-01
Full Text Available Stress-induced ROS changes DNA methylation patterns. A protocol combining methylation-sensitive restriction endonuclease (MS-RE digestion with suppression subtractive hybridization (SSH to construct the differential-methylation subtractive library was developed for finding genes regulated by methylation mechanism under cold stress. The total efficiency of target fragment detection was 74.64%. DNA methylation analysis demonstrated the methylation status of target fragments changed after low temperature or DNA methyltransferase inhibitor treatment. Transcription level analysis indicated that demethylation of DNA promotes gene expression level. The results proved that our protocol was reliable and efficient to obtain gene fragments in differential-methylation status.
5. Renormalizing the NN interaction with multiple subtractions
Timoteo, V.S. [Faculdade de Tecnologia, Universidade Estadual de Campinas, 13484-332 Limeira, SP (Brazil); Frederico, T. [Instituto Tecnologico de Aeronautica, Comando de Tecnologia Aeroespacial, 12228-900 Sao Jose dos Campos, SP (Brazil); Delfino, A. [Departamento de Fisica, Universidade Federal Fluminense, 24210-150 Niteroi, RJ (Brazil); Tomio, L. [Instituto de Fisica Teorica, Universidade Estadual Paulista, 01140-070 Sao Paulo, SP (Brazil); Szpigel, S.; Duraes, F.O. [Centro de Ciencias e Humanidades, Universidade Presbiteriana Mackenzie, 01302-907 Sao Paulo, SP (Brazil)
2010-02-15
The aim of this work is to show how to renormalize the nucleon-nucleon interaction at next-to-next-to-leading order using a systematic subtractive renormalization approach with multiple subtractions. As an example, we calculate the phase shifts for the partial waves with total angular momentum J=2. The intermediate driving terms at each recursive step as well as the renormalized T-matrix are also shown. We conclude that our method is reliable for singular potentials such as the two-pion exchange and derivative contact interactions.
6. Removal of power-line interference from the ECG: a review of the subtraction procedure
Christov Ivaylo
2005-08-01
Full Text Available Abstract Background Modern biomedical amplifiers have a very high common mode rejection ratio. Nevertheless, recordings are often contaminated by residual power-line interference. Traditional analogue and digital filters are known to suppress ECG components near to the power-line frequency. Different types of digital notch filters are widely used despite their inherent contradiction: tolerable signal distortion needs a narrow frequency band, which leads to ineffective filtering in cases of larger frequency deviation of the interference. Adaptive filtering introduces unacceptable transient response time, especially after steep and large QRS complexes. Other available techniques such as Fourier transform do not work in real time. The subtraction procedure is found to cope better with this problem. Method The subtraction procedure was developed some two decades ago, and almost totally eliminates power-line interference from the ECG signal. This procedure does not affect the signal frequency components around the interfering frequency. Digital filtering is applied on linear segments of the signal to remove the interference components. These interference components are stored and further subtracted from the signal wherever non-linear segments are encountered. Results Modifications of the subtraction procedure have been used in thousands of ECG instruments and computer-aided systems. Other work has extended this procedure to almost all possible cases of sampling rate and interference frequency variation. Improved structure of the on-line procedure has worked successfully regardless of the multiplicity between the sampling rate and the interference frequency. Such flexibility is due to the use of specific filter modules. Conclusion The subtraction procedure has largely proved advantageous over other methods for power-line interference cancellation in ECG signals.
7. Detecting cerebral vascular diseases by transcranial Doppler ultrasound and dolor Doppler flow imaging in comparison with digital subtracted angiography%经颅多普勒及彩色多普勒超声与数字减影脑血管造影对脑血管病检测的比较研究
张小征; 吕健; 李俊; 胡军民; 龚杰; 徐国政; 马廉亭; 陈欣林
2000-01-01
目的 评价经颅多普勒(TCD)在脑血管病诊断、疗效评估中的应用价值.方法 应用TCD检测脑血管疾病患者306例,其中脑动静脉畸形170例,颈动脉海绵窦瘘(CCF)69例,颅内动脉瘤67例,并与数字减影脑血管造影(DSA)、彩色多普勒血流显像(CDFI)进行对比研究.结果 以DSA脑血管造影为金指标,TCD检出脑动静脉畸形93%,检出CCF 100%,判断CCF静脉回流方式96%,检出颅内动脉瘤67%.对颅内较大动脉瘤(>1．5 cm)的检测有特征性表现,提出"动脉瘤样频谱"的新概念.结论 TCD能实时、准确反映颅内血流动力学改变及侧支循环代偿情况,对脑血管病诊断、疗效评估有重要价值.%Objective To evaluate the effect of transcranial Doppler(TCD)on detecting cerebral vascular diseases．Methods One hundred and seventy patients with cerebral arterovenous malformation(AVM),69 carotid cavernous fistula (CCF)and 67 intracranial aneurysms were examined early or late by TCD, digital subtracted angiography(DSA)and color Dopplor flow imaging．The results of their examination were compared and analyzed．Results If the results of DSA examination was regarded as a golden criterion of diagnosing the cerebral vascular dNease,93%of the 170 patients with AVMs,100% of the 69 patients with CCFS and 67％of the 67 patients with the aneurysms were detected by TCD respectively．It was found that the relative larger aneurysm(diameter>1．5 crn)had a special TCD manifestation, the SO-called ”aneurysm-like spectrum”． Conclusion TCD is necessary for detecting the cerebral vascular lesions because it can reveal accurately a change in the intracranial hemodynamics and a condition of the collateral circulation．
8. Follow-up of intracranial aneurysms treated by flow diverter: comparison of three-dimensional time-of-flight MR angiography (3D-TOF-MRA) and contrast-enhanced MR angiography (CE-MRA) sequences with digital subtraction angiography as the gold standard.
Attali, Jonathan; Benaissa, Azzedine; Soize, Sébastien; Kadziolka, Krzysztof; Portefaix, Christophe; Pierot, Laurent
2016-01-01
Follow-up of intracranial aneurysms treated by flow diverter with MRI is complicated by imaging artifacts produced by these devices. This study compares the diagnostic accuracy of three-dimensional time-of-flight MR angiography (3D-TOF-MRA) and contrast-enhanced MRA (CE-MRA) at 3 T for the evaluation of aneurysm occlusion and parent artery patency after flow diversion treatment, with digital subtraction angiography (DSA) as the gold standard. Patients treated with flow diverters between January 2009 and January 2013 followed by MRA at 3 T (3D-TOF-MRA and CE-MRA) and DSA within a 48 h period were included in a prospective single-center study. Aneurysm occlusion was assessed with full and simplified Montreal scales and parent artery patency with three-grade and two-grade scales. Twenty-two patients harboring 23 treated aneurysms were included. Interobserver agreement using simplified scales for occlusion (Montreal) and parent artery patency were higher for DSA (0.88 and 0.61) and CE-MRA (0.74 and 0.55) than for 3D-TOF-MRA (0.51 and 0.02). Intermodality agreement was higher for CE-MRA (0.88 and 0.32) than for 3D-TOF-MRA (0.59 and 0.11). CE-MRA yielded better accuracy than 3D-TOF-MRA for aneurysm remnant detection (sensitivity 83% vs 50%; specificity 100% vs 100%) and for the status of the parent artery (specificity 63% vs 32%; sensitivity 100% vs 100%). At 3 T, CE-MRA is superior to 3D-TOF-MRA for the evaluation of aneurysm occlusion and parent artery patency after flow diversion treatment. However, intraluminal evaluation remains difficult with MRA regardless of the sequence used. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
9. 多层螺旋CT对孤立性肠系膜上动脉夹层的诊断价值及与数字减影血管造影的对比分析%Comparison of diagnostic value between multislice CT and digital subtraction angiography in isolated supe-rior mesenteric artery dissection
张杨贵; 何旭升; 温志玲; 陈珊红; 高振华; 许俊丽
2016-01-01
目的：探讨64层螺旋CT血管成像及后处理技术对孤立性肠系膜上动脉夹层（SISMAD）的诊断价值，及与数字减影血管造影对比分析。方法回顾分析17例使用64层螺旋CT及数字减影血管造影（DSA）所发现的孤立性肠系膜上动脉夹层，结合横断位原始图像及各后处理方法重建图像，分析其影像征像。结果64层螺旋CT血管成像动脉期能清晰显示肠系膜上动脉及其低密度的内膜片，真假腔及破裂口显示良好，夹层累及范围，是否存在血栓及累及分支血管，术后追踪观察方便、准确。结论多层螺旋CT能清晰显示孤立性肠系膜上动脉夹层的病变特征，其检出率、并发症显示优于DSA，并能较好地指导DSA介入治疗及预后观察，是孤立性肠系膜上动脉夹层首选的无创检查方法。%Objective To compare the diagnostic value between 64-slice CT and digital subtraction angiogra-phy (DSA) in isolated superior mesenteric artery (SISMAD) dissection. Methods Retrospective study was taken in 17 patients with SMA Dissection, evidenced by both 64-slice CT and DSA,analyze the eikonic signs according to trans-verse view and reconstruction images. Results In artetial phase, multislice CT could clearly showed superior mesen-teric artery, its hypodense intimal orifice, true and false double lumen and oral cleft, intercalated bed range involved, with or without thrombus and lateral branch blood vessels could be indicated well, which had great convenience to follow-up postoperative. Conclusion Multislice CT, an atraumatic mothod for SMA dissection, could clearly present its pathological changes. It also has better detection rate and less complication compared with DAS. Moreover, multi-slice CT could help to direct treatment by DSA.
10. Diagnosis of Subtraction Bugs Using Bayesian Networks
Lee, Jihyun; Corter, James E.
2011-01-01
Diagnosis of misconceptions or "bugs" in procedural skills is difficult because of their unstable nature. This study addresses this problem by proposing and evaluating a probability-based approach to the diagnosis of bugs in children's multicolumn subtraction performance using Bayesian networks. This approach assumes a causal network relating…
11. Polygon Subtraction in 2 or 3 Dimensions
Wilson, John E.
2013-10-01
When searching for computer code to perform the ubiquitous task of subtracting one polygon from another, it is difficult to find real examples and detailed explanations. This paper outlines the step-by-step process necessary to accomplish this basic task.
12. Robust Background Subtraction with Incremental Eigen Models
Gritti, T.
2008-01-01
In this report we first describe a background subtraction algorithm based on the use of eigen space decomposition. We then present a method to achive incremental modelling, which allows for faster computation and saving in memory requirements. We discuss the performanceof the algorithm and the issu
13. Children's Understanding of Addition and Subtraction Concepts
Robinson, Katherine M.; Dube, Adam K.
2009-01-01
After the onset of formal schooling, little is known about the development of children's understanding of the arithmetic concepts of inversion and associativity. On problems of the form a+b-b (e.g., 3+26-26), if children understand the inversion concept (i.e., that addition and subtraction are inverse operations), then no calculations are needed…
14. Video Background Subtraction in Complex Environments
Juana E. Santoyo-Morales
2014-06-01
Full Text Available Background subtraction models based on mixture of Gaussians have been extensively used for detecting objects in motion in a wide variety of computer vision applications. However, background subtraction modeling is still an open problem particularly in video scenes with drastic illumination changes and dynamic backgrounds (complex backgrounds. The purpose of the present work is focused on increasing the robustness of background subtraction models to complex environments. For this, we proposed the following enhancements: a redefine the model distribution parameters involved in the detection of moving objects (distribution weight, mean and variance, b improve pixel classification (background/foreground and variable update mechanism by a new time-space dependent learning-rate parameter, and c replace the pixel-based modeling currently used in the literature by a new space-time region-based model that eliminates the noise effect caused by drastic changes in illumination. Our proposed scheme can be implemented on any state of the art background subtraction scheme based on mixture of Gaussians to improve its resilient to complex backgrounds. Experimental results show excellent noise removal and object motion detection properties under complex environments.
15. Rod strain after pedicle subtraction osteotomy
Gehrchen, Poul Martin; Hallager, Dennis Winge; Dahl, Benny
2016-01-01
Pedicle subtraction osteotomy (PSO) can provide major sagittal correction for adult spinal deformity, sometimes achieving correction greater than 308. Surgeons have reported failure rates up to 30% within 2 years, increasing to 46% after 4 to 5 years (SDC Figure 1, http://links.lww.com/BRS/B87). ...
16. Robust Optimization-Based Coronary Artery Labeling From X-Ray Angiograms.
Liu, Xinglong; Hou, Fei; Qin, Hong; Hao, Aimin
2016-11-01
In this paper, we present an efficient robust labeling method for coronary arteries from X-ray angiograms based on energy optimization. The fundamental goal of this research is to facilitate the analysis and diagnosis of interventional surgery in the most efficient way, and such effort could also improve the performance during doctor training, and surgery simulation and planning. Compared to the prior state-of-the-art, our method is much more robust to resist noises and is tolerant to even incomplete data because of the "built-in" nature of global optimization. We start with a fully parallelized algorithm based on Hessian matrix to extract the tubular structure from the X-ray angiograms as vessel candidates. Then, instead of using the candidates directly, we use the grow cut (Vezhnevets and V. Konouchine, Growcut: Interactive multi-label N-D image segmentation by cellular automata, in Proc. of Graphicon, 2005, pp. 150-156.) method, which is similar to graph cut (Boykov et al. , Fast approximate energy minimization via graph cuts, IEEE Trans. Pattern Anal. Mach. Intell. , vol. 23, no. 11, pp. 1222-1239, Nov. 2001.)but with better performance to extract the precise vessel structure from the images. Next, we use the fast marching method with second derivatives and cross neighbors to extract the accurate skeleton segments. After that, we propose an efficient method based on iterative closest point (Z. Zhang, Iterative point matching for registration of free-form curves and surfaces, Int J. Comput. Vis., vol. 13, no. 2, pp. 119-152, 1994.) to organize the skeleton segments by treating the continuity and similarity as extra constraints. Finally, we formulate the vessel labeling problem as an energy optimization problem and solve it using belief propagation. We also demonstrate several typical applications including flow velocity estimation, heart beat estimation, and vessel diameter estimation to show its practical uses in clinical diagnosis and treatment. Our
17. Evaluation of angiogram visualization methods for fast and reliable aneurysm diagnosis
Lesar, Žiga; Bohak, Ciril; Marolt, Matija
2015-03-01
In this paper we present the results of an evaluation of different visualization methods for angiogram volumetric data-ray casting, marching cubes, and multi-level partition of unity implicits. There are several options available with ray-casting: isosurface extraction, maximum intensity projection and alpha compositing, each producing fundamentally different results. Different visualization methods are suitable for different needs, so this choice is crucial in diagnosis and decision making processes. We also evaluate visual effects such as ambient occlusion, screen space ambient occlusion, and depth of field. Some visualization methods include transparency, so we address the question of relevancy of this additional visual information. We employ transfer functions to map data values to color and transparency, allowing us to view or hide particular tissues. All the methods presented in this paper were developed using OpenCL, striving for real-time rendering and quality interaction. An evaluation has been conducted to assess the suitability of the visualization methods. Results show superiority of isosurface extraction with ambient occlusion effects. Visual effects may positively or negatively affect perception of depth, motion, and relative positions in space.
18. Dimensions of the foveal avascular zone using the Heidelberg retinal angiogram-2 in normal eyes
John Deepa
2011-01-01
Full Text Available Purpose: The purpose was to study the dimensions of the foveal avascular zone (FAZ using Heidelberg Retinal Angiogram-2 (HRA-2; Heidelberg Engineering GmBH, Dossenheim, Germany. Materials and Methods: An observational study of the FAZ area and circumference was done with fundus fluorescein angiography (FFA using HRA-2 in 31 normal individuals. The FAZ was studied using both contrast-adjusted and nonadjusted methods. Contrast adjustment was done to obtain better visualization of the finer capillaries around the fovea enabling more precise measurements of the FAZ in normal eyes. Results: The mean area of the FAZ calculated by the contrast-adjusted method was 0.2753 mm 2 (±0.074 and the mean circumference was 2.22 mm (±0.048. By the conventional method, the area and circumference of the FAZ were 0.6241 mm 2 (±0.177 and 3.23 mm (±0.454, respectively. Conclusion: The measurements of area and circumference of FAZ using contrast-adjusted methods were significantly smaller than the conventional method.
19. 3D imaging of myocardial perfusion and coronary tree morphology from a single rotational angiogram
Lauritsch, Günter; Rohkohl, Christopher; Hornegger, Joachim; Sinha, Anil-Martin; Brachmann, Johannes; Rieber, Johannes; Rittger, Harald
2011-03-01
Diagnosis and treatment of coronary heart disease are performed in the catheter laboratory using an angiographic X-ray C-arm system. The morphology of the coronary tree and potentially ischemic lesions are determined in 2D projection views. The hemodynamic impact of the lesion would be valuable information for treatment decision. Using other modalities for functional imaging is disrupting the clinical workflow since the patient has to be transferred from the catheter laboratory to another scanner, and back to the catheter laboratory for performing the treatment. In this work a novel technology is used for simultaneous 3D imaging of first pass perfusion and the morphology of the coronary tree from a single rotational angiogram. A selective, single shot of contrast agent of less than 20ml directly into the coronaries is sufficient for a proper contrast resolution. Due to the long acquisition time cardiac motion has to be considered. A novel reconstruction technique for estimation and compensation of cardiac motion from the acquired projection data is used. The overlay of the 3D structure of the coronary tree and the perfusion image shows the correlation of myocardial areas and the associated coronary sections supporting that region. In a case example scar lesions caused by a former myocardial infarct are investigated. A first pass perfusion defect is found which is validated by a late enhancement magnetic resonance image. No ischemic defects are found. The non vital regions are still supported by the coronary vasculature.
20. Triple Rule Out versus CT Angiogram Plus Stress Test for Evaluation of Chest Pain in the Emergency Department
Sawyer, Kelly N.; Payal Shah; Lihua Qu; Kurz, Michael C.; Clark, Carol L.; Swor, Robert A.
2015-01-01
Introduction: Undifferentiated chest pain in the emergency department (ED) is a diagnostic challenge. One approach includes a dedicated chest computed tomography (CT) for pulmonary embolism or dissection followed by a cardiac stress test (TRAD). An alternative strategy is a coronary CT angiogram with concurrent chest CT (Triple Rule Out, TRO). The objective of this study was to describe the ED patient course and short-term safety for these evaluation methods. Methods: This was ...
1. Motion Tracking with Fast Adaptive Background Subtraction
Xiao; De-Gui; Yu; Sheng-sheng; 等
2003-01-01
To extract and track moving objects is usually one of the most important tasks of intelligent video surveillance systems. This paper presents a fast and adaptive background subtraction algorithm and the motion tracking process using this algorithm. The algorithm uses only luminance components of sampled image sequence pixels and models every pixel in a statistical model.The algorithm is characterized by its ability of real time detecting sudden lighting changes, and extracting and tracking motion objects faster. It is shown that our algorithm can be realized with lower time and space complexity and adjustable object detection error rate with comparison to other background subtraction algorithms. Making use of the algorithm, an indoor monitoring system is also worked out and the motion tracking process is presented in this paper.Experimental results testify the algorithms' good performances when used in an indoor monitoring system.
2. Interferometry with Photon-Subtracted Thermal Light
Rafsanjani, Seyed Mohammad Hashemi; Magana-Loaiza, Omar S; Gard, Bryan T; Birrittella, Richard; Koltenbah, B E; Parazzoli, C G; Capron, Barbara A; Gerry, Christopher C; Dowling, Jonathan P; Boyd, Robert W
2016-01-01
We propose and implement a quantum procedure for enhancing the sensitivity with which one can determine the phase shift experienced by a weak light beam possessing thermal statistics in passing through an interferometer. Our procedure entails subtracting exactly one (which can be generalized to m) photons from the light field exiting an interferometer containing a phase-shifting element in one of its arms. As a consequence of the process of photon subtraction, and somewhat surprisingly, the mean photon number and signal-to-noise ratio of the resulting light field are thereby increased, leading to enhanced interferometry. This method can be used to increase measurement sensitivity in a variety of practical applications, including that of forming the image of an object illuminated only by weak thermal light.
3. Customized CT angiogram planning for intraoperative transesophageal echography-guided endovascular exclusion of thoracic aorta penetrating ulcer.
Piazza, Michele; Lupia, Mario; Grego, Franco; Antonello, Michele
2015-04-01
The technique is demonstrated in a 78-year-old man; the preoperative CT angiogram showed a descending thoracic aorta ulcer of 5.9 cm in maximum diameter and 3.8 cm longitudinal extension. A ZTEG-2P-36-127-PF (Cook Medical) single tubular endograft was planned to be deployed. From the preoperative CT angiogram we planned to land 4.7 cm above the midline of the descending thoracic aorta ulcer and 8.0 cm below. In the operating room, under radioscopic vision the centre of the transesophageal echography probe was used as marker to identify the correspondent midline of the descending thoracic aorta ulcer and a centimeter-sized pigtail catheter in the aorta was used to calculate the desired length above and below the ulcer midline. The endograft was introduced and placed in the desired position compared to the transesophageal echography probe and the catheter; under transesophageal echography vision the graft was finally deployed. The CT angiogram at 1 month showed the correct endograft position, descending thoracic aorta ulcer exclusion with no signs of endoleak. In selected cases, this method allows planning in advance safe stent graft positioning and deployment totally assisted by transesophageal echography, with no risk of periprocedural contrast-related renal failure and reduced radiation exposure for the patient and operators.
4. Moving object detection using background subtraction
Shaikh, Soharab Hossain; Chaki, Nabendu
2014-01-01
This Springer Brief presents a comprehensive survey of the existing methodologies of background subtraction methods. It presents a framework for quantitative performance evaluation of different approaches and summarizes the public databases available for research purposes. This well-known methodology has applications in moving object detection from video captured with a stationery camera, separating foreground and background objects and object classification and recognition. The authors identify common challenges faced by researchers including gradual or sudden illumination change, dynamic bac
5. Blind foreground subtraction for intensity mapping experiments
Alonso, David; Bull, Philip; Ferreira, Pedro G.; Santos, Mário G.
2015-02-01
We make use of a large set of fast simulations of an intensity mapping experiment with characteristics similar to those expected of the Square Kilometre Array in order to study the viability and limits of blind foreground subtraction techniques. In particular, we consider three different approaches: polynomial fitting, principal component analysis (PCA) and independent component analysis (ICA). We review the motivations and algorithms for the three methods, and show that they can all be described, using the same mathematical framework, as different approaches to the blind source separation problem. We study the efficiency of foreground subtraction both in the angular and radial (frequency) directions, as well as the dependence of this efficiency on different instrumental and modelling parameters. For well-behaved foregrounds and instrumental effects, we find that foreground subtraction can be successful to a reasonable level on most scales of interest. We also quantify the effect that the cleaning has on the recovered signal and power spectra. Interestingly, we find that the three methods yield quantitatively similar results, with PCA and ICA being almost equivalent.
6. Subtractive Structural Modification of Morpho Butterfly Wings.
Shen, Qingchen; He, Jiaqing; Ni, Mengtian; Song, Chengyi; Zhou, Lingye; Hu, Hang; Zhang, Ruoxi; Luo, Zhen; Wang, Ge; Tao, Peng; Deng, Tao; Shang, Wen
2015-11-11
Different from studies of butterfly wings through additive modification, this work for the first time studies the property change of butterfly wings through subtractive modification using oxygen plasma etching. The controlled modification of butterfly wings through such subtractive process results in gradual change of the optical properties, and helps the further understanding of structural optimization through natural evolution. The brilliant color of Morpho butterfly wings is originated from the hierarchical nanostructure on the wing scales. Such nanoarchitecture has attracted a lot of research effort, including the study of its optical properties, its potential use in sensing and infrared imaging, and also the use of such structure as template for the fabrication of high-performance photocatalytic materials. The controlled subtractive processes provide a new path to modify such nanoarchitecture and its optical property. Distinct from previous studies on the optical property of the Morpho wing structure, this study provides additional experimental evidence for the origination of the optical property of the natural butterfly wing scales. The study also offers a facile approach to generate new 3D nanostructures using butterfly wings as the templates and may lead to simpler structure models for large-scale man-made structures than those offered by original butterfly wings.
7. Severity Analysis of Neurovascular Contact in Patients with Trigeminal Neuralgia: Assessment with the Inner View of the 3D MR Cisternogram and Angiogram Fusion Imaging
Satoh, T; Omi, M; Nabeshima, M; Onoda, K; Date, I
2009-01-01
.... The frequency and severity of the NVC among the affected, contralateral, and normal trigeminal nerves were analyzed by 3D MR cisternogram and angiogram fusion imaging in relation to the cause of TN...
8. High-risk carotid plaques identified by CT-angiogram can predict acute myocardial infarction.
Mosleh, Wassim; Adib, Keenan; Natdanai, Punnanithinont; Carmona-Rubio, Andres; Karki, Roshan; Paily, Jacienta; Ahmed, Mohamed Abdel-Aal; Vakkalanka, Sujit; Madam, Narasa; Gudleski, Gregory D; Chung, Charles; Sharma, Umesh C
2016-11-19
Prior studies identified the incremental value of non-invasive imaging by CT-angiogram (CTA) to detect high-risk coronary atherosclerotic plaques. Due to their superficial locations, larger calibers and motion-free imaging, the carotid arteries provide the best anatomic access for the non-invasive characterization of atherosclerotic plaques. We aim to assess the ability of predicting obstructive coronary artery disease (CAD) or acute myocardial infarction (MI) based on high-risk carotid plaque features identified by CTA. We retrospectively examined carotid CTAs of 492 patients that presented with acute stroke to characterize the atherosclerotic plaques of the carotid arteries and examined development of acute MI and obstructive CAD within 12-months. Carotid lesions were defined in terms of calcifications (large or speckled), presence of low-attenuation plaques, positive remodeling, and presence of napkin ring sign. Adjusted relative risks were calculated for each plaque features. Patients with speckled (<3 mm) calcifications and/or larger calcifications on CTA had a higher risk of developing an MI and/or obstructive CAD within 1 year compared to patients without (adjusted RR of 7.51, 95%CI 1.26-73.42, P = 0.001). Patients with low-attenuation plaques on CTA had a higher risk of developing an MI and/or obstructive CAD within 1 year than patients without (adjusted RR of 2.73, 95%CI 1.19-8.50, P = 0.021). Presence of carotid calcifications and low-attenuation plaques also portended higher sensitivity (100 and 79.17%, respectively) for the development of acute MI. Presence of carotid calcifications and low-attenuation plaques can predict the risk of developing acute MI and/or obstructive CAD within 12-months. Given their high sensitivity, their absence can reliably exclude 12-month events.
9. Effect of color coding and subtraction on the accuracy of contrast echocardiography
Pasquet, A.; Greenberg, N.; Brunken, R.; Thomas, J. D.; Marwick, T. H.
1999-01-01
BACKGROUND: Contrast echocardiography may be used to assess myocardial perfusion. However, gray scale assessment of myocardial contrast echocardiography (MCE) is difficult because of variations in regional backscatter intensity, difficulties in distinguishing varying shades of gray, and artifacts or attenuation. We sought to determine whether the assessment of rest myocardial perfusion by MCE could be improved with subtraction and color coding. METHODS AND RESULTS: MCE was performed in 31 patients with previous myocardial infarction with a 2nd generation agent (NC100100, Nycomed AS), using harmonic triggered or continuous imaging and gain settings were kept constant throughout the study. Digitized images were post processed by subtraction of baseline from contrast data and colorized to reflect the intensity of myocardial contrast. Gray scale MCE alone, MCE images combined with baseline and subtracted colorized images were scored independently using a 16 segment model. The presence and severity of myocardial contrast abnormalities were compared with perfusion defined by rest MIBI-SPECT. Segments that were not visualized by continuous (17%) or triggered imaging (14%) after color processing were excluded from further analysis. The specificity of gray scale MCE alone (56%) or MCE combined with baseline 2D (47%) was significantly enhanced by subtraction and color coding (76%, pcolorized images (59%) was also significantly greater than gray scale MCE (43% and 29%, pcolor coding significantly improves the accuracy and specificity of MCE for detection of perfusion defects.
10. Application of flat-panel digital subtraction angiography in interventional therapy for carotid cavernous fistutas:initial clinical experience%平板DSA新技术在介入治疗颈内动脉海绵窦瘘中应用初探
石强; 梁传声; 臧培卓; 徐克
2009-01-01
Objective To assess the clinical value offlat-panel digital subtraction angiography (DSA)in interventional therapy for carotid-cavemous fistula (CCF). Methods Three-dimensional (3D)DSA Was performed in 12 patients with CCF before the interventional therapy.The fistular orifice was located and measured with multiplanar reconstruction technique,and the Landscap roadmap of the fistula was obtained.Fistula embolization was performed according to the location of the fistular orifice and the surrounding bony marker indicated by 3D and Landscap roadmap. Results The fistular orifices were clearly displayed in the 12 patients with an average orifice diameter of 3.7 mm.The intemal carotid artery(ICA)and the bony marker of the cavernous sinus were shown simultaneously.Ten patients received endovascular embolization wiith detachable balloon, and 1 patient was treated wiith coil and 1 with stent placement.The ICA remained patent in 11 cases and carotid artery occlusion was performed in 1 case. Conclusion The 3D flat-panel DSA provides rich infolrmati,Ion on the fistular orifice,,and the bony markers can be identified by landscape roadmap technique..The combination of these two techniques guarantees effective and safe treatment of CCE.%目的 探讨平板DSA新技术在介入治疗颈内动脉海绵窦瘘(CCF)中的应用价值.方法 12例CCF患者术前行3DDSA检查,应用多平面重建技术定位瘘口并对瘘口进行测量.治疗中利用可调控实时透视路途技术(Landscap技术)制作路径图,以3D图像所示瘘口及周围骨性标志作为对照进行封堵治疗.结果 12例CCF均可清晰定位瘘口,瘘口直径平均3.7 mm.利用Landscap技术使颈内动脉路径及海绵窦骨性标志同时可见.球囊栓塞10例,弹簧圈栓塞1例,支架封堵瘘口1例.颈内动脉通畅11例,1例行颈内动脉闭塞.结论 平板DSA 3D技术提供了瘘口的丰富信息,Landscap技术为治疗增加了骨性标志,其联合应用为治疗CCF提供了安全保障.
11. Comparison of contrast-enhanced MR angiography of the aortoiliac vessels using a 1.0 molar contrast agent at 1.0T with intra-arterial digital subtraction angiography; Ergebnisse der kontrastverstaerkten MR-Angiographie der aortoiliakalen Gefaesse mit einem 1-molaren Kontrastmittel bei 1,0 T; Vergleich zur i.a. DSA
Mohrs, O.K. [Klinik und Poliklinik fuer Radiologie, Johannes Gutenberg-Univ. Mainz (Germany); Cardioangiologisches Centrum Bethanien, Frankfurt/Main (Germany); Oberholzer, K.; Bernhard, S.; Kalden, P.; Thelen, M.; Kreitner, K.F. [Klinik und Poliklinik fuer Radiologie, Johannes Gutenberg-Univ. Mainz (Germany); Krummenauer, F. [Inst. fuer Med. Biometrie, Epidemiologie und Informatik, Johannes Gutenberg-Univ. Mainz (Germany); Neufang, A. [Klinik fuer Herz- und Thoraxchirurgie, Johannes Gutenberg-Univ. Mainz (Germany)
2004-07-01
Purpose: To evaluate the diagnostic accuracy of contrast-enhanced MR angiography (CE-MRA) using a 1.0 molar contrast agent at 1.0 T for the diagnosis of abdominal aortic aneurysms and stenoses of renal or iliac arteries in comparison to intraarterial digital subtraction angiography (DSA). Materials and Methods: A total of 19 patients with the suspicion of abdominal aortic aneurysm or stenosis of renal or iliac arteries were examined with CE-MRA at 1.0 T. Intra-arterial DAS served as reference in all cases. After test bolus tracking, 10 or 8 ml of the 1.0 molar contrast agent Gadobutrol corresponding to a dose of 0.1-0.15 mmol/kg bw were injected and imaging performed using a FLASH-3D sequence. To evaluate the interobserver-variability, the blinded images were analyzed by two radiologists. Besides the rating of overall image quality on a 4-point-scale, the images were evaluated for aneurysms and arteriosclerotic lesions with a stenosis of < 50% or > 50% or occlusion. Results: A total of 144 segments were analyzed. The mean value of the CE-MRA image quality was 3.4 on a 4-point scale. The sensitivity of CE-MRA in depicting relevant pathological findings was 96% and the specifity 99%. The positive predictive value was 96% and the negative predictive value 99%. Inter-observer variability was low with a kappa value of 0.82. Conclusion: CE-MRA using a 1.0 molar contrast agent at 1.0 Tenables an excellent diagnosis or exclusion of pathologies of the aortoiliac vessels. (orig.) [German] Ziel: Vergleich der MR-Angiographie (ce-MRA) der aortoiliakalen Gefaesse unter Verwendung eines 1-molaren, paramagnetischen Kontrastmittels bei 1,0 T zur intraarteriellen digitalen Subtraktionsangiographie (i.a. DSA). Material und Methoden: Es wurden 19 Patienten mit Verdacht auf ein infrarenales Aortenaneurysma bzw. eine Stenose der Nieren- oder Iliakalarterien untersucht. Die Messungen erfolgten bei 1,0 T unter Verwendung des 1-molaren, paramagnetischen Kontrastmittels Gadobutrol
12. Bone images from dual-energy subtraction chest radiography in the detection of rib fractures
Szucs-Farkas, Zsolt, E-mail: [email protected] [Department of Diagnostic, Interventional and Pediatric Radiology, University Hospital Bern, Freiburgstrasse 4, Bern CH-3010 (Switzerland); Lautenschlager, Katrin, E-mail: [email protected] [Department of Diagnostic, Interventional and Pediatric Radiology, University Hospital Bern, Freiburgstrasse 4, Bern CH-3010 (Switzerland); Flach, Patricia M., E-mail: [email protected] [Institute of Forensic Medicine, University of Bern, Freiburgstrasse 4, Bern CH-3010 (Switzerland); Ott, Daniel, E-mail: [email protected] [Department of Diagnostic, Interventional and Pediatric Radiology, University Hospital Bern, Freiburgstrasse 4, Bern CH-3010 (Switzerland); Strautz, Tamara, E-mail: [email protected] [Department of Diagnostic, Interventional and Pediatric Radiology, University Hospital Bern, Freiburgstrasse 4, Bern CH-3010 (Switzerland); Vock, Peter, E-mail: [email protected] [Department of Diagnostic, Interventional and Pediatric Radiology, University Hospital Bern, Freiburgstrasse 4, Bern CH-3010 (Switzerland); Ruder, Thomas D., E-mail: [email protected] [Institute of Forensic Medicine, University of Bern, Freiburgstrasse 4, Bern CH-3010 (Switzerland)
2011-08-15
Objective: To assess the sensitivity and image quality of chest radiography (CXR) with or without dual-energy subtracted (ES) bone images in the detection of rib fractures. Materials and methods: In this retrospective study, 39 patients with 204 rib fractures and 24 subjects with no fractures were examined with a single exposure dual-energy subtraction digital radiography system. Three blinded readers first evaluated the non-subtracted posteroanterior and lateral chest radiographs alone, and 3 months later they evaluated the non-subtracted images together with the subtracted posteroanterior bone images. The locations of rib fractures were registered with confidence levels on a 3-grade scale. Image quality was rated on a 5-point scale. Marks by readers were compared with fracture localizations in CT as a standard of reference. Results: The sensivity for fracture detection using both methods was very similar (34.3% with standard CXR and 33.5% with ES-CXR, p = 0.92). At the patient level, both sensitivity (71.8%) and specificity (92.9%) with or without ES were identical. Diagnostic confidence was not significantly different (2.61 with CXR and 2.75 with ES-CXR, p = 0.063). Image quality with ES was rated higher than that on standard CXR (4.08 vs. 3.74, p < 0.001). Conclusions: Despite a better image quality, adding ES bone images to standard radiographs of the chest does not provide better sensitivity or improved diagnostic confidence in the detection of rib fractures.
13. Confirmation of T1-Bright Vein of Galen Aneurysm Spontaneous Thrombosis by Subtraction Magnetic Resonance Venography: A Case Report
Irfan, M.; Lohman, B.; McKinney, A.M. (Dept. of Radiology/Neuroradiology, Univ. of Minnesota, Minneapolis, Minnesota (United States))
2009-08-15
Spontaneous thrombosis of a vein of Galen aneurysmal malformation (VOGM) is rare. We describe a 2-month-old patient with a patent VOGM and hydrocephalus, also confirmed patent at 6 months, but with subsequent lack of filling on pre-embolization catheter digital subtraction angiography (DSA) at 9 months' age. Due to the presence of T1- and T2-bright signal, noncontrast T1-weighted images (T1WI), T2-weighted images (T2WI), two-dimensional (2D) time-of-flight (TOF) magnetic resonance venography (MRV), and postcontrast T1WI were ambiguous for patency. However, subtracting the pre- from the postcontrast MRV images confirmed closure compared to subtracted images at 6 months' age. The factors contributing to thrombosis were likely a combination of a disproportionately small straight sinus, ventriculostomy, and contrast medium from DSA.
14. Parallel decompositions of Mueller matrices and polarimetric subtraction
Gil J.J.
2010-06-01
Full Text Available From a general formulation of the physically realizable parallel decompositions of the Mueller matrix M of a given depolarizing system, a procedure for determining the set of pure Mueller matrices susceptible to be subtracted from M is presented. This procedure provides a way to check if a given pure Mueller matrix N can be subtracted from M or not. If this check is positive, the value of the relative cross section of the subtracted component is also determined.
15. Parallel decompositions of Mueller matrices and polarimetric subtraction
Gil J.J.
2010-01-01
From a general formulation of the physically realizable parallel decompositions of the Mueller matrix M of a given depolarizing system, a procedure for determining the set of pure Mueller matrices susceptible to be subtracted from M is presented. This procedure provides a way to check if a given pure Mueller matrix N can be subtracted from M or not. If this check is positive, the value of the relative cross section of the subtracted component is also determined.
16. Perfusion-weighted imaging and dynamic 4D angiograms for the estimation of collateral blood flow in lacunar infarction.
Förster, Alex; Mürle, Bettina; Böhme, Johannes; Al-Zghloul, Mansour; Kerl, Hans U; Wenz, Holger; Groden, Christoph
2016-10-01
Although lacunar infarction accounts for approximately 25% of ischemic strokes, collateral blood flow through anastomoses is not well evaluated in lacunar infarction. In 111 lacunar infarction patients, we analyzed diffusion-weighted images, perfusion-weighted images, and blood flow on dynamic four-dimensional angiograms generated by use of Signal Processing In NMR-Software. Blood flow was classified as absent (type 1), from periphery to center (type 2), from center to periphery (type 3), and combination of type 2 and 3 (type 4). On diffusion-weighted images, lacunar infarction was found in the basal ganglia (11.7%), internal capsule (24.3%), corona radiata (30.6%), thalamus (24.3%), and brainstem (9.0%). In 58 (52.2%) patients, perfusion-weighted image showed a circumscribed hypoperfusion, in one (0.9%) a circumscribed hyperperfusion, whereas the remainder was normal. In 36 (62.1%) patients, a larger perfusion deficit (>7 mm) was observed. In these, blood flow was classified type 1 in four (11.1%), 2 in 17 (47.2%), 3 in 9 (25.0%), and 4 in six (16.7%) patients. Patients with lacunar infarction in the posterior circulation more often demonstrated blood flow type 2 and less often type 3 (p = 0.01). Detailed examination and graduation of blood flow in lacunar infarction by use of dynamic four-dimensional angiograms is feasible and may serve for a better characterization of this stroke subtype.
17. Analysis of Hysterosalpingography in 1369 Infertility Patients with Water Soluble Contrast Medium under Digital Subtraction Angiography%1369例不孕患者水溶性造影剂DSA下动态子宫输卵管造影分析
田芳玲; 陈硕飞; 王海峰; 曲尔青; 郭晓丽; 田锦林
2014-01-01
目的：探讨原发性不孕（PI）与继发性不孕（SI）患者子宫输卵管造影（HSG）的特点及导致输卵管不通畅的危险因素。方法回顾性分析1369例不孕患者的水溶性造影剂DSA下HSG造影资料，根据不孕的原因为PI及SI两组，对两组一般情况及造影结果进行比较；再以双侧输卵管通畅与否为因变量，以年龄、生育史、是否有宫外孕史、盆腔手术史、输卵管结核病史、流产史、原发或继发性不孕、合并其它疾病与否、子宫形态异常与否为自变量，进行多因素二分类logistic回归分析，探讨输卵管不通畅的危险因素。结果 PI组年龄比SI组小[（27.27±3.82）岁vs（29.97±4.80）岁]，双侧输卵管通畅率较SI组高（45.50%vs 34.74%），两组比较有统计学差异（P<0.05）；Logistic回归分析显示年龄、宫外孕史、流产史及子宫形态异常是输卵不通畅的危险因素(OR值=0.903、0.198、1.542、0.120；95%的可信区间：0.903～0.958、0.120～0.352、1.002～2.375、0.036～0.399)。结论 PI和SI在年龄及输卵管通畅率方面存在差异，大龄、宫外孕史、流产史及子宫形态异常是输卵不通畅的危险因素。%Objective To analysis the hysterosalpingography(HSG) features of primary infertile(PI) and secondary infertile(SI) patients and related risk factors of Fallopian tubal blockage and incomplete patency. Methods Digital subtraction angiography(DSA) imaging data of HSG with water soluble contrast medium in 1369 infertile patients were retrospectively analyzed. Patients were divided into two groups according to etiopathogenisis of infertility, including PI group and SI group. The general states and appearance of HSG were compared between the two groups. And then, with bilateral tubal patency or not as a dependent, and with age,childbearing history or not, ectopic pregnancy(EP) history or not, pelvic surgery history or not, tubal tuberculosis history or not
18. Analysis of the anatomical relationship between the uterine artery and the bony landmarks in cesarean scar pregnancy by CT angiography and digital subtraction angiography%剖宫产瘢痕妊娠子宫动脉开口位置与骨性标志关系的 CT 血管成像与DSA 研究
熊浪; 王进华; 孙进; 邓美香; 郑伟增; 肖新兰
2015-01-01
目的：利用 CTA 与 DSA 技术,采用骶髂垂直分段定位法探讨剖宫产术后子宫瘢痕妊娠(CSP)患者子宫动脉开口位置与骨性解剖标志的关系。方法回顾性分析2013年10月—2014年6月浙江大学医学院附属妇产科医院收治的91例 CSP 患者的临床资料和 CTA、DSA 影像学资料。患者年龄23~44岁,平均(32.7±4.2)岁。在骶髂关节骶骨面中,以骶骨的最高点(如左侧 A 点)与髂骨左右两侧的最低点(a、b)为骨盆骨性解剖标志。采用骶髂垂直分段定位法连接 a、b 两点做一水平线 ab,从 A 点向 ab 水平线做一垂线,交点为 D 点,B、C 等分 AD,将骶髂垂直等分为 AB、BC、CD 和 D点远端4段,在患者 CTA 与 DSA 图片上,观察统计患者双侧子宫动脉开口位置在各段的分布情况。结果91例182支子宫动脉中,3支子宫动脉已结扎,CTA 与 DSA 均未见其显示；179支子宫动脉显影,子宫动脉开口位置左侧低于右侧,左侧在 AB、BC、CD 及 D 点远端的比例为0%(0)、3.3%(3/90)、70.0%(63/90)及26.7%(24/90),右侧的比例为0%(0)、11.2%(10/89)、85.4%(76/89)及3.4%(3/89),左右两侧均以 CD 段所占比例最多,两侧在各段分布构成情况差异有统计学意义(χ2=22.618,P <0.01)。结论 CSP 患者子宫动脉开口位置在骶髂各段中分布具有一定的特征,当 CSP患者子宫动脉栓塞治疗无法准确判断子宫动脉开口位置时,利用骶髂垂直分段定位法可为介入治疗提供新的影像学指导和参考。%Objective To investigate the anatomical relationship between the uterine artery and the adjacent bony landmarks in cesarean scar pregnancy ( CSP ) with the method of sacroiliac vertical segmentation localization using CT angiography ( CTA ) and digital subtraction angiography ( DSA ). Methods From October 2013 to June 2014, 91 patients of CSP were examined by CTA and DSA in Department of Radiology of the Women′s Hospital of Medicine Zhejiang University. The
19. 多层螺旋CT与数字减影血管造影诊断下消化道出血的比较%Comparison Between Multislice Spiral CT and Digital Subtraction Angiography in the Diagnosis of Lower Digestive Tract Hemorrhage
石磊; 邹文远; 陈光斌; 胡久民
2012-01-01
目的:通过与数字减影血管造影(DSA)的对照分析,评价多层螺旋CT(MSCT)对下消化道出血的诊断价值.方法:临床怀疑下消化道出血的29例患者进行MSCT增强扫描,并结合MSCT多平面重组(MPR)、最大密度投影(MIP)等后处理模式对图像进行分析判断,找出出血部位及供血动脉,与DSA对照来评估MSCT血管成像技术对于显示下消化道出血的敏感性、准确率.结果:①MSCT显示出血部位25例,出血显示率86.2％(25/29).DSA检查发现出血灶22例,出血显示率75.9％ (22/29).MSCT对于发现出血部位的敏感性和DSA无显著差异(P＞0.05).②MSCT显示以下出血部位:空回肠出血9例,结肠出血16例,诊断肿瘤15例,炎症4例,憩室2例,溃疡2例,血管畸形1例,未明确病因1例.MSCT未见异常的4例DSA均表现阴性.DSA显示的出血部位:小肠8例,结肠14例,术中诊断肿瘤10例,血管畸形1例,其余11例未明确病因.统计结果表明:MSCT对于下消化道出血的病因诊断准确率明显高于DSA(P＜0.05).结论:MSCT对于判断下消化道出血部位的敏感性可与DSA相媲美,并且能较准确地进行病因诊断,具有较高的临床应用价值,可作为下消化道出血性疾病的常规首选检查方法.%Objective: To evaluate multislice spiral CT (MSCT) in the diagnosis of lower digestive tract hemorrhage as compared with digital subtraction angiography (DSA). Methods: Twenty-nine cases of suspected lower digestive tract bleeding received MSCT enhanced scan, combined with multiplanar reformation (MPR) , maximum intensity projection (MIP) image analysis, to identify the bleeding site and the supplying artery. The results were compared with those of DSA to evaluate the sensitivity and accuracy of MSCT. Results: MSCT showed the bleeding sites of the 25 cases (86.2%) while DSA found 22 sites of bleeding (75. 9%). MSCT showed 9 cases of jejunum and ileum bleeding, 16 cases of colonic bleeding, 15 cases of tumor, 4 cases of
20. Astronomical Image Subtraction by Cross-Convolution
Yuan, Fang; Akerlof, Carl W.
2008-04-01
In recent years, there has been a proliferation of wide-field sky surveys to search for a variety of transient objects. Using relatively short focal lengths, the optics of these systems produce undersampled stellar images often marred by a variety of aberrations. As participants in such activities, we have developed a new algorithm for image subtraction that no longer requires high-quality reference images for comparison. The computational efficiency is comparable with similar procedures currently in use. The general technique is cross-convolution: two convolution kernels are generated to make a test image and a reference image separately transform to match as closely as possible. In analogy to the optimization technique for generating smoothing splines, the inclusion of an rms width penalty term constrains the diffusion of stellar images. In addition, by evaluating the convolution kernels on uniformly spaced subimages across the total area, these routines can accommodate point-spread functions that vary considerably across the focal plane.
1. Digital imaging primer
Parkin, Alan
2016-01-01
Digital Imaging targets everyyone with an interest in digital imaging, be they professional or private, who uses even quite modest equipment such as a PC, digital camera and scanner, a graphics editor such as Paint, and an inkjet printer. Uniquely, it is intended to fill the gap between highly technical texts for academics (with access to expensive equipment) and superficial introductions for amateurs. The four-part treatment spans theory, technology, programs and practice. Theory covers integer arithmetic, additive and subtractive color, greyscales, computational geometry, and a new presentation of discrete Fourier analysis; Technology considers bitmap file structures, scanners, digital cameras, graphic editors, and inkjet printers; Programs develops several processing tools for use in conjunction with a standard Paint graphics editor and supplementary processing tools; Practice discusses 1-bit, greyscale, 4-bit, 8-bit, and 24-bit images for the practice section. Relevant QBASIC code is supplied an accompa...
2. Tomography of photon-added and photon-subtracted states
Bazrafkan, MR; Man'ko, [No Value
2003-01-01
The purpose of this paper is to introduce symplectic and optical tomograms of photon-added and photon-subtracted quantum states. Explicit relations for the tomograms of photon-added and photon-subtracted squeezed coherent states and squeezed number states are obtained. Generating functions for the m
3. Developing a Model to Support Students in Solving Subtraction
Murdiyani, N.M.; Zulkardi, Z.; Putri, R.I.; van Eerde, H.A.A.; van Galen, F.H.J.
2013-01-01
Subtraction has two meanings and each meaning leads to the different strategies. The meaning of “taking away something” suggests a direct subtraction, while the meaning of “determining the difference between two numbers” is more likely to be modeled as indirect addition. Many prior researches found
4. Developing a Model to Support Students in Solving Subtraction
Murdiyani, N.M.; Zulkardi, Z.; Putri, R.I.; van Eerde, H.A.A.|info:eu-repo/dai/nl/071855343; van Galen, F.H.J.|info:eu-repo/dai/nl/069437025
2013-01-01
Subtraction has two meanings and each meaning leads to the different strategies. The meaning of “taking away something” suggests a direct subtraction, while the meaning of “determining the difference between two numbers” is more likely to be modeled as indirect addition. Many prior researches found
5. Developing a Model to Support Students in Solving Subtraction
Murdiyani, Nila Mareta; Zulkardi; Putri, Ratu Ilma Indra; van Eerde, Dolly; van Galen, Frans
2013-01-01
Subtraction has two meanings and each meaning leads to the different strategies. The meaning of "taking away something" suggests a direct subtraction, while the meaning of "determining the difference between two numbers" is more likely to be modeled as indirect addition. Many prior researches found that the second meaning and…
6. Tomography of photon-added and photon-subtracted states
Bazrafkan, MR; Man'ko, [No Value
The purpose of this paper is to introduce symplectic and optical tomograms of photon-added and photon-subtracted quantum states. Explicit relations for the tomograms of photon-added and photon-subtracted squeezed coherent states and squeezed number states are obtained. Generating functions for the
7. [Construction of subtractive cDNA libraries of the sporogony stage of Eimeria tenella by suppression subtractive hybridization].
Han, Hong-Yu; Lin, Jiao-Jiao; Zhao, Qi-Ping; Dong, Hui; Jiang, Lian-Lian; Wang, Xin; Han, Jing-Fang; Huang, Bing
2007-11-01
In order to clone and identify differentially expressed genes in the sporogony stage of Eimeria tenella, the cDNAs from unsporulated oocysts and sporulated oocysts of E. tenella were used as driver, respectively, the cDNAs from sporozoites of E. tenella was used tester, Two subtractive cDNA libraries of sporozoites were constructed by using the technique of suppression subtractive hybridization (SSH). the cDNAs from unsporulated oocysts was used driver, the cDNAs from sporulated ooceysts was used tester, one subtractive cDNA library of sporulated oocysts was constructed. PCR amplification revealed that the two subtractive cDNA libraries of sporozoites and one subtractive cDNA library of sporulated oocysts contained approximated 96%, 96% and 98% recombinant clones, respectively. Fifty positive clones were sequenced and analyzed in GenBank with Blast search from three subtractive cDNA libraries, respectively, thirteen unique sequences were found from the subtractive cDNA library of sporulated oocysts, eight ESTs shared significant identity with previously described. A total of forty unique sequences were obtained from the two subtractive cDNA libraries, nine ESTs shared significant identity with previously described, the other sequences represent novel genes of E. tenella with no significant homology to the proteins in Genbank. These results have provided the foundation for cloning new genes of E. tenella and further studying new approaches to control coccidiosis.
8. Accessing the diffracted wavefield by coherent subtraction
Schwarz, Benjamin; Gajewski, Dirk
2017-10-01
Diffractions have unique properties which are still rarely exploited in common practice. Aside from containing subwavelength information on the scattering geometry or indicating small-scale structural complexity, they provide superior illumination compared to reflections. While diffraction occurs arguably on all scales and in most realistic media, the respective signatures typically have low amplitudes and are likely to be masked by more prominent wavefield components. It has been widely observed that automated stacking acts as a directional filter favouring the most coherent arrivals. In contrast to other works, which commonly aim at steering the summation operator towards fainter contributions, we utilize this directional selection to coherently approximate the most dominant arrivals and subtract them from the data. Supported by additional filter functions which can be derived from wave front attributes gained during the stacking procedure, this strategy allows for a fully data-driven recovery of faint diffractions and makes them accessible for further processing. A complex single-channel field data example recorded in the Aegean sea near Santorini illustrates that the diffracted background wavefield is surprisingly rich and despite the absence of a high channel count can still be detected and characterized, suggesting a variety of applications in industry and academia.
9. Gd-enhanced subtraction MR venography
Hoshi, Toshiko; Hachiya, Takashi; Kanauchi, Tetsu; Hando, Yumiko; Homma, Tsuguo [Saitama Cardiovascular and Respiratory Center, Konan (Japan)
1999-10-01
We succeeded in distinctly imaging the calf veins using Gd-enhanced subtraction MR venography (Gd SMRV). Gd SMRV was performed in 15 normal legs, 33 varicose legs and 22 legs with suspected deep venous thrombosis. Conventional venography was performed in 46 legs in all. The deep veins of the calf, greater saphenous vein, and intramuscular veins had high rates of demonstration in normal legs and varicose legs (84, 100%, 87, 97%, 67, 73%). The varices were also well demonstrated (100%). When Gd SMRV was compared with conventional venography in terms of diagnosis of calf venous thrombosis, the sensitivity of this method was 100%, specificity was 92% and accuracy was 93%. We found high intensity thrombi on precontrast images in most cases, a finding that was important for the diagnosis of local thrombi. This method was non-invasive and was able to clearly visualize veins in the calf. We concluded that Gd SMRV was useful for calf venous disease, especially calf venous thrombosis. (author)
10. Manifestations of hepatic cavernous hemangioma in carbon dioxidedigital subtraction angiography
LU Wei; LI Yan-ha0; HE Xiao-feng; CHEN Yong; ZENG Qing-le
2002-01-01
Objective: To describe the characteristic appearance of cavernous hemangioma of the liver (CHL)presented in carbon dioxide digital subtraction angiography (CO2-DSA) and to evaluate the significance of CO2-DSA in the diagnosis of CHL. Methods: Both CO2-DSA and iodinated contrast DSA (IC-DSA) were performed in all 16 patients with CHL, and the angiographic manifestations in the same patients were compared. The image quality was rated by three experienced angiographers, and the complications were also assessed. Results; There was good correlation between angiographers on image quality (R=0. 73). Diagnostic images were obtained with both CO2-DSA and IC-DSA in all CHL patients. No difference was noted between IC-DSA and CO2-DSA in visualizing the proper hepatic arteries and its branches (P＞0. 05). CO2-DSA produced better images that clearly described the tumor size, shape and margination than those by IC-DSA (P＜0. 05), but both demonstrated characteristic appearances of early opacification and persistent contrast enhancement of the tumors. The portal vein branches near the tumors were constantly demonstrated by CO2-DSA in 15 cases (15/16) but only in 2 cases (2/16) by IC-DSA. Conclusion: CO2-DSA is sensitive in CHL diagnosis, and in patients with contraindications to IC or with unsatisfactory imaging results by IC-DSA,CO2-DSA is a good alternative. As show in most cases by CO2-DSA, the portal veins might act as the main drainage vein of CHLs.
11. Bi-Event Subtraction Technique at Hadron Colliders
Dutta, Bhaskar; Kolev, Nikolay; Krislock, Abram
2011-01-01
We propose the Bi-Event Subtraction Technique (BEST) as a method of modeling and subtracting large portions of the combinatoric background which arises during reconstruction of particle decay chains at particle colliders. The combinatoric background arises because it is impossible to know experimentally which observed particles come from the decay chain of interest. BEST models this combinatoric background by combining observable particles from different collision events. The combinatoric background modeled by BEST can then be subtracted away, greatly reducing the overall background. This technique can be applied towards two goals of hadron colliders: To improve our understanding of the Standard Model and to search for new physics beyond the Standard Model.
12. Improvements in floating point addition/subtraction operations
Farmwald, P.M.
1984-02-24
Apparatus is described for decreasing the latency time associated with floating point addition and subtraction in a computer, using a novel bifurcated, pre-normalization/post-normalization approach that distinguishes between differences of floating point exponents.
13. An auto-adaptive background subtraction method for Raman spectra
Xie, Yi; Yang, Lidong; Sun, Xilong; Wu, Dewen; Chen, Qizhen; Zeng, Yongming; Liu, Guokun
2016-05-01
Background subtraction is a crucial step in the preprocessing of Raman spectrum. Usually, parameter manipulating of the background subtraction method is necessary for the efficient removal of the background, which makes the quality of the spectrum empirically dependent. In order to avoid artificial bias, we proposed an auto-adaptive background subtraction method without parameter adjustment. The main procedure is: (1) select the local minima of spectrum while preserving major peaks, (2) apply an interpolation scheme to estimate background, (3) and design an iteration scheme to improve the adaptability of background subtraction. Both simulated data and Raman spectra have been used to evaluate the proposed method. By comparing the backgrounds obtained from three widely applied methods: the polynomial, the Baek's and the airPLS, the auto-adaptive method meets the demand of practical applications in terms of efficiency and accuracy.
14. Increasing Entanglement between Gaussian States by Coherent Photon Subtraction
Ourjoumtsev, Alexei; Dantan, Aurelien Romain; Tualle Brouri, Rosa
2007-01-01
We experimentally demonstrate that the entanglement between Gaussian entangled states can be increased by non-Gaussian operations. Coherent subtraction of single photons from Gaussian quadrature-entangled light pulses, created by a nondegenerate parametric amplifier, produces delocalized states w...
Lloyd, G.A.S.; Barker, P.G.; Phelps, P.D. (Royal National Throat, Nose and Ear Hospital, London (United Kingdom))
1993-01-01
The subtraction method of Des Plantes was applied to gadolinium enhanced magnetic resonance imaging (GdMR). Using short acquisition times, T[sub 1] weighted spin echo pulse sequences are made immediately before and after intravenous administration of gadolinium DTPA. The needle is placed in the vein prior to putting the patient into the scanner and is irrigated with saline while the control series is obtained. 42 patients with naso-sinus or skull base tumours have been successfully investigated by this technique and satisfactory subtraction studies are now obtained on all patients other than the claustrophobic. Subtraction GdMR provides the best demonstration of the effects of gadolinium DTPA on the magnetic resonance signal for both normal and abnormal tissues. Tbe signal recorded on the subtraction image is dependent on tissue blood supply and provides a more accurate record of tumour extent than that shown by unsubtracted GdMR scans. (author).
16. Background Subtraction for Automated Multisensor Surveillance: A Comprehensive Review
Cristani Marco
2010-01-01
Full Text Available Background subtraction is a widely used operation in the video surveillance, aimed at separating the expected scene (the background from the unexpected entities (the foreground. There are several problems related to this task, mainly due to the blurred boundaries between background and foreground definitions. Therefore, background subtraction is an open issue worth to be addressed under different points of view. In this paper, we propose a comprehensive review of the background subtraction methods, that considers also channels other than the sole visible optical one (such as the audio and the infrared channels. In addition to the definition of novel kinds of background, the perspectives that these approaches open up are very appealing: in particular, the multisensor direction seems to be well-suited to solve or simplify several hoary background subtraction problems. All the reviewed methods are organized in a novel taxonomy that encapsulates all the brand-new approaches in a seamless way.
17. Background Subtraction for Automated Multisensor Surveillance: A Comprehensive Review
Cristani, Marco; Farenzena, Michela; Bloisi, Domenico; Murino, Vittorio
2010-12-01
Background subtraction is a widely used operation in the video surveillance, aimed at separating the expected scene (the background) from the unexpected entities (the foreground). There are several problems related to this task, mainly due to the blurred boundaries between background and foreground definitions. Therefore, background subtraction is an open issue worth to be addressed under different points of view. In this paper, we propose a comprehensive review of the background subtraction methods, that considers also channels other than the sole visible optical one (such as the audio and the infrared channels). In addition to the definition of novel kinds of background, the perspectives that these approaches open up are very appealing: in particular, the multisensor direction seems to be well-suited to solve or simplify several hoary background subtraction problems. All the reviewed methods are organized in a novel taxonomy that encapsulates all the brand-new approaches in a seamless way.
18. Differential cDNA cloning by enzymatic degrading subtraction (EDS).
1994-01-01
We describe a new method, called enzymatic degrading subtraction (EDS), for the construction of subtractive libraries from PCR amplified cDNA. The novel features of this method are that i) the tester DNA is blocked by thionucleotide incorporation; ii) the rate of hybridization is accelerated by phenol-emulsion reassociation; and iii) the driver cDNA and hybrid molecules are enzymatically removed by digestion with exonucleases III and VII rather than by physical partitioning. We demonstrate th...
19. IR subtraction schemes. Integrating the counterterms at NNLO in QCD
Bolzoni, Paolo; Somogyi, Gabor
2010-06-15
We briefly review a subtraction scheme for computing radiative corrections to QCD jet cross sections that can be defined at any order in perturbation theory. Hereafter we discuss the computational methods used to evaluate analytically and numerically the integrated counterterms arising from such a subtraction scheme. Basically these methods the Mellin-Barnes (MB) representations technique together with the harmonic summation and the sector decomposition. (orig.)
20. Voxel significance mapping in epilepsy studies using subtraction ictal SPECT
Brinkmann, Benjamin H.; O'Brien, Terence J.; Webster, Desmond B.; Robins, Peter D.; Mullan, Brian P.; Robb, Richard A.
1999-05-01
Subtraction ictal SPECT coregistered to MRI (SISCOM) has been shown to aid epileptogenic localization and improve surgical outcomes in partial epilepsy patients. This paper reports a new method of identifying significant areas of epileptogenic activation in the SISCOM subtraction image taking into account normal variation between sequential Tc-99m Ethyl Cysteinate Diethylester SPECT scans of single individuals. The method uses the AIR 3.0 nonlinear registration software to combine a group of subtraction images into a common anatomical framework. A map of the pixel intensity standard deviation values in the subtraction images is created, and this map is nonlinearly registered to a patient's SISCOM subtraction image. Pixels in the patient subtraction image may then be evaluated based upon the statistical characteristics of corresponding pixels in the atlas. Validation experiments were performed to verify that local image variances are not constant across the image and that nonlinear registration preserves local image variances. SISCOM images created with the voxel variance method were rated higher in quality than the conventional image variance method in images from fifteen patients. No difference in localization rate was observed between the voxel variance mapping and image variance methods. The voxel significance mapping method was shown to improve the quality of clinical SISCOM images without removing localizing information.
1. Advanced Background Subtraction Applied to Aeroacoustic Wind Tunnel Testing
Bahr, Christopher J.; Horne, William C.
2015-01-01
An advanced form of background subtraction is presented and applied to aeroacoustic wind tunnel data. A variant of this method has seen use in other fields such as climatology and medical imaging. The technique, based on an eigenvalue decomposition of the background noise cross-spectral matrix, is robust against situations where isolated background auto-spectral levels are measured to be higher than levels of combined source and background signals. It also provides an alternate estimate of the cross-spectrum, which previously might have poor definition for low signal-to-noise ratio measurements. Simulated results indicate similar performance to conventional background subtraction when the subtracted spectra are weaker than the true contaminating background levels. Superior performance is observed when the subtracted spectra are stronger than the true contaminating background levels. Experimental results show limited success in recovering signal behavior for data where conventional background subtraction fails. They also demonstrate the new subtraction technique's ability to maintain a proper coherence relationship in the modified cross-spectral matrix. Beam-forming and de-convolution results indicate the method can successfully separate sources. Results also show a reduced need for the use of diagonal removal in phased array processing, at least for the limited data sets considered.
2. Statistically tuned Gaussian background subtraction technique for UAV videos
R Athi Lingam; K Senthil Kumar
2014-08-01
Background subtraction is one of the efficient techniques to segment the targets from non-informative background of a video. The traditional background subtraction technique suits for videos with static background whereas the video obtained from unmanned aerial vehicle has dynamic background. Here, we propose an algorithm with tuning factor and Gaussian update for surveillance videos that suits effectively for aerial videos. The tuning factor is optimized by extracting the statistical features of the input frames.With the optimized tuning factor and Gaussian update an adaptive Gaussian-based background subtraction technique is proposed. The algorithm involves modelling, update and subtraction phases. This running Gaussian average based background subtraction technique uses updation at both model generation phase and subtraction phase. The resultant video extracts the moving objects from the dynamic background. Sample videos of various properties such as cluttered background, small objects, moving background and multiple objects are considered for evaluation. The technique is statistically compared with frame differencing technique, temporal median method and mixture of Gaussian model and performance evaluation is done to check the effectiveness of the proposed technique after optimization for both static and dynamic videos.
3. Evaluation of sacroiliitis: contrast-enhanced MRI with subtraction technique
Algin, Oktay; Gokalp, Gokhan; Baran, Bulent; Ocakoglu, Gokhan; Yazici, Zeynep [Uludag University, Medical Faculty, Department of Radiology, Gorukle, Bursa (Turkey)
2009-10-15
The purpose of the study was to investigate the diagnostic value of contrast-enhanced MRI using the subtraction technique in the detection of active sacroiliitis. Magnetic resonance imaging was performed in 8 asymptomatic volunteers and 50 patients with clinically suspected active sacroiliitis. On precontrast MR images, T1-weighted spin-echo images with and without fat saturation (T1WFS and T1W), STIR and 3D-FLASH images with fat saturation were obtained in the semicoronal plane using a 1.5 Tesla imager. Postcontrast MRI was performed using the same T1WFS sequence as before contrast injection for all volunteers and patients. Postcontrast images were subtracted from fat-suppressed precontrast images. Enhancement within the joint space and bone marrow was considered to demonstrate active sacroiliitis. In 50 patients (100 sacroiliac joints [SIJs]), 40 (76 SIJs) were considered to have active sacroiliitis based on MR images. Bone marrow edema was present in 33 patients (62 SIJs) on STIR images. Routine MRI allowed identification of contrast enhancement in SIJs on postcontrast T1WFS images in 31 patients (49 SIJs). Contrast enhancement was observed in 40 patients (76 SIJs) who were examined by MRI using the subtraction technique. Contrast enhancement was significantly more conspicuous on subtraction images than on non-subtracted postcontrast T1WFS images (Mann-Whitney U test, p<0.001). Contrast-enhanced MRI with subtraction technique may be useful for early detection of active sacroiliitis. (orig.)
4. Assessment of diffuse coronary artery disease by quantitative analysis of coronary morphology based upon 3-D reconstruction from biplane angiograms.
Wahle, A; Wellnhofer, E; Mugaragu, I; Saner, H U; Oswald, H; Fleck, E
1995-01-01
Quantitative evaluations on coronary vessel systems are of increasing importance in cardiovascular diagnosis, therapy planning, and surgical verification. Whereas local evaluations, such as stenosis analysis, are already available with sufficient accuracy, global evaluations of vessel segments or vessel subsystems are not yet common. Especially for the diagnosis of diffuse coronary artery diseases, the authors combined a 3D reconstruction system operating on biplane angiograms with a length/volume calculation. The 3D reconstruction results in a 3D model of the coronary vessel system, consisting of the vessel skeleton and a discrete number of contours. To obtain an utmost accurate model, the authors focussed on exact geometry determination. Several algorithms for calculating missing geometric parameters and correcting remaining geometry errors were implemented and verified. The length/volume evaluation can be performed either on single vessel segments, on a set of segments, or on subtrees. A volume model based on generalized elliptical conic sections is created for the selected segments. Volumes and lengths (measured along the vessel course) of those elements are summed up. In this way, the morphological parameters of a vessel subsystem can be set in relation to the parameters of the proximal segment supplying it. These relations allow objective assessments of diffuse coronary artery diseases.
5. Towards Predicting Patient-Specific Flow-Diverter Treatment Outcomes for Bifurcation Aneurysms: From Implantation Rehearsal to Virtual Angiograms.
Peach, T W; Spranger, K; Ventikos, Y
2016-01-01
Despite accounting for the majority of all cerebral aneurysm cases, bifurcation aneurysms present many challenges to standard endovascular treatment techniques. This study examines the treatment of bifurcation aneurysms endovascularly with flow-diverting stents and presents an integrative computational modeling suite allowing for rehearsing all aspects of the treatment. Six bifurcation aneurysms are virtually treated with 70% porosity flow-diverters. Substantial reduction (>50%) in aneurysm inflow due to device deployment is predicted in addition to reductions in peak and average aneurysm wall shear stress to values considered physiologically normal. The subsequent impact of flow-diverter deployment on daughter vessels that are jailed by the device is investigated further, with a number of simulations conducted with increased outlet pressure conditions at jailed vessels. Increased outlet pressures at jailed daughter vessels are found to have little effect on device-induced aneurysm inflow reduction, but large variation (13-86%) is seen in the resulting reduction in daughter vessel flow rate. Finally, we propose a potentially powerful approach for validation of such models, by introducing an angiographic contrast model, with contrast transport modeled both before and after virtual treatment. Virtual angiograms and contrast residence curves are created, which offer unique clinical relevance and the potential for future in vivo verification of simulated results.
6. Subtraction and dynamic MR images of breast cancer
Murakami, Yoshitaka; Aoki, Manabu; Harada, Junta (Jikei Univ., Tokyo (Japan). School of Medicine)
1993-04-01
The purpose of this study was to evaluate the diagnostic effectiveness of subtraction and dynamic MR imaging in patients with breast masses. In 23 breast cancers and six fibroadenomas, spin echo T1 images were obtained at 0.2 Tesla before and every minute after intravenous injection of Gd-DTPA (0.1 or 0.2 mmol/kg). Subtraction images were obtained sequentially on the CRT monitor. All breast masses were enhanced after gadolinium and stood out as bright lesions on subtraction images. The tumor margin and its extension were more precisely evaluated on subtraction MR images than on conventional postcontrast MR images. Breast cancer showed a characteristic time-intensity curve with an early peak, in contrast to fibroadenoma, which showed a gradual increase in signal intensity. Subtraction MR imaging is a simple method for the evaluation of breast masses, and further, the time-intensity curve obtained by dynamic study is helpful in the differential diagnosis of lesions. (author).
7. Blind Source Separation Algorithms for PSF Subtraction from Direct Imaging
Shapiro, Jacob; Ranganathan, Nikhil; Savransky, Dmitry; Ruffio, Jean-Baptise; Macintosh, Bruce; GPIES Team
2017-01-01
The principal difficulty with detecting planets via direct imaging is that the target signal is similar in magnitude, or fainter, than the noise sources in the image. To compensate for this, several methods exist to subtract the PSF of the host star and other confounding noise sources. One of the most effective methods is Karhunen-Loève Image Processing (KLIP). The core algorithm within KLIP is Principal Component Analysis, which is a member of a class of algorithms called Blind Source Separation (BSS).We examine three other BSS algorithms that may potentially also be used for PSF subtraction: Independent Component Analysis, Stationary Subspace Analysis, and Common Spatial Pattern Filtering. The underlying principles of each of the algorithms is discussed, as well as the processing steps needed to achieve PSF subtraction. The algorithms are examined both as primary PSF subtraction techniques, as well as additional postprocessing steps used with KLIP.These algorithms have been used on data from the Gemini Planet Imager, analyzing images of β Pic b. To build a reference library, both Angular Differential Imaging and Spectral Differential Imaging were used. To compare to KLIP, three major metrics are examined: computation time, signal-to-noise ratio, and astrometric and photometric biases in different image regimes (e.g., speckle-dominated compared to Poisson-noise dominated). Preliminary results indicate that these BSS algorithms improve performance when used as an enhancement for KLIP, and that they can achieve similar SNR when used as the primary method of PSF subtraction.
8. Appearance of the canine meninges in subtraction magnetic resonance images.
Lamb, Christopher R; Lam, Richard; Keenihan, Erin K; Frean, Stephen
2014-01-01
The canine meninges are not visible as discrete structures in noncontrast magnetic resonance (MR) images, and are incompletely visualized in T1-weighted, postgadolinium images, reportedly appearing as short, thin curvilinear segments with minimal enhancement. Subtraction imaging facilitates detection of enhancement of tissues, hence may increase the conspicuity of meninges. The aim of the present study was to describe qualitatively the appearance of canine meninges in subtraction MR images obtained using a dynamic technique. Images were reviewed of 10 consecutive dogs that had dynamic pre- and postgadolinium T1W imaging of the brain that was interpreted as normal, and had normal cerebrospinal fluid. Image-anatomic correlation was facilitated by dissection and histologic examination of two canine cadavers. Meningeal enhancement was relatively inconspicuous in postgadolinium T1-weighted images, but was clearly visible in subtraction images of all dogs. Enhancement was visible as faint, small-rounded foci compatible with vessels seen end on within the sulci, a series of larger rounded foci compatible with vessels of variable caliber on the dorsal aspect of the cerebral cortex, and a continuous thin zone of moderate enhancement around the brain. Superimposition of color-encoded subtraction images on pregadolinium T1- and T2-weighted images facilitated localization of the origin of enhancement, which appeared to be predominantly dural, with relatively few leptomeningeal structures visible. Dynamic subtraction MR imaging should be considered for inclusion in clinical brain MR protocols because of the possibility that its use may increase sensitivity for lesions affecting the meninges.
9. Coronary Artery Calcification Is Often Unreported in CT Pulmonary Angiograms in Patients With Suspected Pulmonary Embolism: An Opportunity to Improve Diagnosis of Acute Coronary Syndrome
Johnson, Patrick Connor
2015-01-01
Objective: In patients with suspected pulmonary thromboembolism (PTE), coronary artery calcification (CAC) can be an incidental finding in CT pulmonary angiograms. We evaluated the frequency of unreported CAC and its association with diagnosis of acute coronary syndrome (ACS). Methods: The data of 469 consecutive patients who were referred to the emergency radiology department for CT pulmonary angiography because of suspicion for PTE were reviewed. Radiology reports were rechecked, and pos...
10. Non-contrast-enhanced MR angiography in critical limb ischemia: performance of quiescent-interval single-shot (QISS) and TSE-based subtraction techniques
Altaha, Mustafa A. [University Health Network, Department of Medical Imaging, Peter Munk Cardiac Centre, Toronto, Ontario (Canada); Jaskolka, Jeffrey D.; Tan, Kongteng; Menezes, Ravi J. [University Health Network, Department of Medical Imaging, Peter Munk Cardiac Centre, Toronto, Ontario (Canada); University of Toronto, Department of Medical Imaging, Toronto, Ontario (Canada); Rick, Manuela; Schmitt, Peter [Siemens Healthcare, Erlangen (Germany); Wintersperger, Bernd J. [University Health Network, Department of Medical Imaging, Peter Munk Cardiac Centre, Toronto, Ontario (Canada); University of Toronto, Department of Medical Imaging, Toronto, Ontario (Canada); Toronto General Hospital, Department of Medical Imaging, Toronto, Ontario (Canada)
2017-03-15
The aim of this study was to evaluate diagnostic performance of non-contrast-enhanced 2D quiescent-interval single-shot (QISS) and 3D turbo spin-echo (TSE)-based subtraction magnetic resonance angiography (MRA) in the assessment of peripheral arteries in patients with critical limb ischemia (CLI). Nineteen consecutive patients (74 % male, 72.8 ± 9.9 years) with CLI underwent 2D QISS and 3D TSE-based subtraction MRA at 1.5 T. Axial-overlapping QISS MRA (3 mm/2 mm; 1 x 1 mm{sup 2}) covered from the toes to the aortic bifurcation while coronal 3D TSE-based subtraction MRA (1.3 x 1.2 x 1.3 mm{sup 3}) was restricted to the calf only. MRA data sets (two readers) were evaluated for stenosis (≥50 %) and image quality. Results were compared with digital subtraction angiography (DSA). Two hundred and sixty-seven (267) segments were available for MRA-DSA comparison, with a prevalence of stenosis ≥50 % of 41.9 %. QISS MRA was rated as good to excellent in 79.5-96.0 % of segments without any nondiagnostic segments; 89.8-96.1 % of segments in 3D TSE-based subtraction MRA were rated as nondiagnostic or poor. QISS MRA sensitivities and specificities (segmental) were 92 % and 95 %, respectively, for reader one and 81-97 % for reader two. Due to poor image quality of 3D TSE-based subtraction MRA, diagnostic performance measures were not calculated. QISS MRA demonstrates excellent diagnostic performance and higher robustness than 3D TSE-based subtraction MRA in the challenging patient population with CLI. (orig.)
11. pyKLIP: PSF Subtraction for Exoplanets and Disks
Wang, Jason J.; Ruffio, Jean-Baptise; De Rosa, Robert J.; Aguilar, Jonathan; Wolff, Schuyler G.; Pueyo, Laurent
2015-06-01
pyKLIP subtracts out the stellar PSF to search for directly-imaged exoplanets and disks using a Python implementation of the Karhunen-Loève Image Projection (KLIP) algorithm. pyKLIP supports ADI, SDI, and ADI+SDI to model the stellar PSF and offers a large array of PSF subtraction parameters to optimize the reduction. pyKLIP relies on a minimal amount of dependencies (numpy, scipy, and astropy) and parallelizes the KLIP algorithm to speed up the reduction. pyKLIP supports GPI and P1640 data and can interface with other data sources with the addition of new modules. It also can inject simulated planets and disks as well as automatically search for point sources in PSF-subtracted data.
12. Proper image subtraction - optimal transient detection, photometry and hypothesis testing
Zackay, Barak; Gal-Yam, Avishay
2016-01-01
Transient detection and flux measurement via image subtraction stand at the base of time domain astronomy. Due to the varying seeing conditions, the image subtraction process is non-trivial, and existing solutions suffer from a variety of problems. Starting from basic statistical principles, we develop the optimal statistic for transient detection, flux measurement and any image-difference hypothesis testing. We derive a closed-form statistic that: (i) Is mathematically proven to be the optimal transient detection statistic in the limit of background-dominated noise; (ii) Is numerically stable; (iii) For accurately registered, adequately sampled images, does not leave subtraction or deconvolution artifacts; (iv) Allows automatic transient detection to the theoretical sensitivity limit by providing credible detection significance; (v) Has uncorrelated white noise; (vi) Is a sufficient statistic for any further statistical test on the difference image, and in particular, allows to distinguish particle hits and ...
13. Accurate Sky Continuum Subtraction with Fibre-fed Spectrographs
Yang, Yanbin; Puech, Mathieu; Flores, Hector; Royer, Frederic; Disseau, Karen; Gonçalves, Thiago; Hammer, François; Cirasuolo, Michele; Evans, Chris; Causi, Gianluca Li; Maiolino, Roberto; Melo, Claudio
2013-01-01
Fibre-fed spectrographs now have throughputs equivalent to slit spectrographs. However, the sky subtraction accuracy that can be reached has often been pinpointed as one of the major issues associated with the use of fibres. Using technical time observations with FLAMES-GIRAFFE, two observing techniques, namely dual staring and cross beam-switching, were tested and the resulting sky subtraction accuracy reached in both cases was quantified. Results indicate that an accuracy of 0.6% on sky subtraction can be reached, provided that the cross beam-switching mode is used. This is very encouraging with regard to the detection of very faint sources with future fibre-fed spectrographs, such as VLT/MOONS or E-ELT/MOSAIC.
14. Proposed smart integrated-optical preprocessor using holographic subtraction
Verber, C. M.; Vahey, D. W.
1979-01-01
The paper presents a proposed integrated-optical preprocessor with a holographic subtraction. It is based on an optical analog of a set of N analog voltages formed by passing an optical plane wave, confined in an electrooptic waveguide, under a set of N electrodes to which the voltages are applied; in the limit in which diffraction is ignored, the wavefront of the emerging guided wave will have superimposed upon it N discrete phase shifts. Processors which operate upon voltages encoded in this manner are being fabricated; they include a comparator in which incoming data are compared to a holographic record of the optical analog of a reference set, and a 'smart' system based upon holographic self-subtraction, in which the processor can independently adapt to changes in background information. The preprocessor operation is described in the screening, identification, and the self-subtraction modes, and implementation of devices in an integrated optical configuration is discussed.
15. Construction of a metastasis-associated gene subtracted cDNA library of human colorectal carcinoma by suppression subtraction hybridization
Li Liang; Yan-Qing Ding; Xin Li; Guang-Zhi Yang; Jun Xiao; Li-Chun Lu; Jin-Hua Zhang
2004-01-01
AIM: To construct a differentially-expressed gene subtracted cDNA library from two colorectal carcinoma (CRC) cell lines with different metastatic phenotypes by suppression subtractive hybridization.METHODS: Two cell lines of human CRC from the same patient were used. SW620 cell line showing highly metastatic potential was regarded as tester in the forward subtractive hybridization, while SW480 cell line with lowly metastatic potential was treated as tester in the reverse hybridization. Suppression subtractive hybridization (SSH)was employed to obtain cDNA fragments of differentially expressed genes for the metastasis of CRC. These fragments were ligated with T vectors, screened through the bluewhite screening system to establish cDNA library.RESULTS: After the blue-white screening, 235 white clones were picked out from the positive-going hybridization and 232 from the reverse. PCR results showed that 200-700 bp inserts were seen in 98% and 91% clones from the forward and reverse hybridizations, respectively.CONCLUSIONS: A subtractive cDNA library of differentially expressed genes specific for metastasis of CRC can be constructed with SSH and T/A cloning techniques.
16. Predictors of Morbidity and Cleavage Plane in Surgical Resection of Pure Convexity Meningiomas Using Cerebrospinal Fluid Sensitive Image Subtraction Magnetic Resonance Imaging
THENIER-VILLA, José LUIS; CAMPOVERDE, Raúl ALEJANDRO GALÁRRAGA; DE LA LAMA ZARAGOZA, Adolfo RAMÓN; ALONSO, Cesáreo CONDE
2017-01-01
17. Comparisons of FIR and IIR implementations of a subtraction-based stimulus artifact rejection algorithm.
Azin, Meysam; Chiel, Hillel J; Mohseni, Pedram
2007-01-01
Finite impulse response (FIR) and infinite impulse response (IIR) temporal filtering techniques are investigated to assess the feasibility of very-large-scale-integrated (VLSI) implementation of a subtraction-based stimulus artifact rejection (SAR) algorithm in implantable, closed-loop neuroprostheses. The two approaches are compared in terms of their system architectures, overall performances, and the associated computational costs. Pre-recorded neural data from an Aplysia californica are used to demonstrate the functionality of the proposed implementations. Digital building blocks for an FIR-based system are also simulated in a 0.18-microm CMOS technology, showing a total power consumption of IIR-based system can further reduce the required power consumption and die area.
18. Quantitative analysis of alveolar bone change following implant placement using intraoral radiographic subtraction
Kimura, Hiroyuki; Kanda, Shigenobu [Kyushu Univ., Fukuoka (Japan). Graduate School of Dental Science; Tanaka, Takemasa [Kyushu Univ., Fukuoka (Japan). Dental Hospital
2002-12-01
The purpose of this study was to develop a procedure for quantitative analysis using intraoral radiographs of alveolar bone after placement of dental implants and to consider the validity of the method. We evaluated the ten patients (2 males and 8 females, average age: 48.4 years-old), who were treated with dental implant operation in the site of mandibular molar region, since October of 1999 until September of 2000 in Kimura Dental Clinic (Kumamoto, Japan). We evaluated the intraoral radiographs taken pre- and post- operatively and at follow-up examination. To detect alveolar bone change on radiograph, we adopted the digital subtraction method. Although the radiographs were taken under an ordinary technique with cone indicator, we did not apply the standardized technique with fixing material customized for each patient. Therefore, we used geometric correction and density compensation before subtraction. We assessed the basic statistical values (mean, variance, kurtosis and skewness) of the region of interest (ROI) of the subtracted images. Also, we noted PPD (probing pocket depth) and BOP (bleeding on probing) at each site as indicators of clinical findings and all implanted sites were classified according to the PPD or BOP, i.e. PPD increased group ''PPD (+)'' and PPD stable group ''PPD (-)'', likewise BOP positive group ''BOP (+)'' and negative group ''BOP (-)''. We considered the statistical values of ROI in each group and compared these findings. Mean and variance values of PPD (+) were higher than those of PPD (-) and there was a significant difference in mean value (p=0.031). Similarly, mean and variance values of BOP (+) were statistically higher than those of BOP (-) (p=0.041 and p=0.0087, respectively). Concerning kurtosis and skewness, there was no difference between PPD (+) and PPD (-), or between BOP (+) and BOP (-). Using our method, the radiographs taken for follow
19. Triple Rule Out versus CT Angiogram Plus Stress Test for Evaluation of Chest Pain in the Emergency Department
Kelly N. Sawyer
2015-10-01
Full Text Available Introduction: Undifferentiated chest pain in the emergency department (ED is a diagnostic challenge. One approach includes a dedicated chest computed tomography (CT for pulmonary embolism or dissection followed by a cardiac stress test (TRAD. An alternative strategy is a coronary CT angiogram with concurrent chest CT (Triple Rule Out, TRO. The objective of this study was to describe the ED patient course and short-term safety for these evaluation methods. Methods: This was a retrospective observational study of adult patients presenting to a large, community ED for acute chest pain who had non-diagnostic electrocardiograms (ECGs and normal biomarkers. We collected demographics, ED length of stay, hospital costs, and estimated radiation exposures. We evaluated 30-day return visits for major adverse cardiac events. Results: A total of 829 patients underwent TRAD, and 642 patients had TRO. Patients undergoing TRO tended to be younger (mean 52.3 vs 56.5 years and were more likely to be male (42.4% vs. 30.4%. TRO patients tended to have a shorter ED length of stay (mean 14.45 vs. 21.86 hours, to incur less cost (median $449.83 vs.$1147.70, and to be exposed to less radiation (median 7.18 vs. 16.6mSv. No patient in either group had a related 30-day revisit. Conclusion: Use of TRO is feasible for assessment of chest pain in the ED. Both TRAD and TRO safely evaluated patients. Prospective studies investigating this diagnostic strategy are needed to further assess this approach to ED chest pain evaluation.
20. Triple Rule Out versus CT Angiogram Plus Stress Test for Evaluation of Chest Pain in the Emergency Department.
Sawyer, Kelly N; Shah, Payal; Qu, Lihua; Kurz, Michael C; Clark, Carol L; Swor, Robert A
2015-09-01
Undifferentiated chest pain in the emergency department (ED) is a diagnostic challenge. One approach includes a dedicated chest computed tomography (CT) for pulmonary embolism or dissection followed by a cardiac stress test (TRAD). An alternative strategy is a coronary CT angiogram with concurrent chest CT (Triple Rule Out, TRO). The objective of this study was to describe the ED patient course and short-term safety for these evaluation methods. This was a retrospective observational study of adult patients presenting to a large, community ED for acute chest pain who had non-diagnostic electrocardiograms (ECGs) and normal biomarkers. We collected demographics, ED length of stay, hospital costs, and estimated radiation exposures. We evaluated 30-day return visits for major adverse cardiac events. A total of 829 patients underwent TRAD, and 642 patients had TRO. Patients undergoing TRO tended to be younger (mean 52.3 vs 56.5 years) and were more likely to be male (42.4% vs. 30.4%). TRO patients tended to have a shorter ED length of stay (mean 14.45 vs. 21.86 hours), to incur less cost (median $449.83 vs.$1147.70), and to be exposed to less radiation (median 7.18 vs. 16.6 mSv). No patient in either group had a related 30-day revisit. Use of TRO is feasible for assessment of chest pain in the ED. Both TRAD and TRO safely evaluated patients. Prospective studies investigating this diagnostic strategy are needed to further assess this approach to ED chest pain evaluation.
1. Subtraction of beam-associated background in R measurement
Yan Wen Biao; Chi Shao Peng; Huang Guang Shun; Zhang Lei; Zhang Li; Zhao Zheng Gu; Dai Yu Mei; Li Hui; Wang Zhi Yong
2002-01-01
Using R scan data collected at BES II detector, the authors study the character of beam-associated background. The authors use the method of f factor and the fitting of event vertices to subtract the residual beam-associated background. The difference between the R values obtained by using these two methods is between 0.3% and 2.3%
2. Addition and Subtraction by Students with Down Syndrome
Herrera, Aurelia Noda; Bruno, Alicia; Gonzalez, Carina; Moreno, Lorenzo; Sanabria, Hilda
2011-01-01
We present a research report on addition and subtraction conducted with Down syndrome students between the ages of 12 and 31. We interviewed a group of students with Down syndrome who executed algorithms and solved problems using specific materials and paper and pencil. The results show that students with Down syndrome progress through the same…
3. "Abuelita" Epistemologies: Counteracting Subtractive Schools in American Education
Gonzales, Sandra M.
2015-01-01
This autoethnographic inquiry examines the intersection of elder epistemology and subtractive education, exploring how one "abuelita" countered her granddaughter's divestment of Mexican-ness. I demonstrate how the grandmother used "abuelita" epistemologies to navigate this tension and resist the assimilative pressures felt…
Nunes, Terezinha; Bryant, Peter; Hallett, Darcy; Bell, Daniel; Evans, Deborah
2009-01-01
Two intervention studies are described. Both were designed to study the effects of teaching children about the inverse relation between addition and subtraction. The interventions were successful with 8-year-old children in Study 1 and to a limited extent with 5-year-old children in Study 2. In Study 1 teaching children about inversion increased…
5. Addition and Subtraction by Students with Down Syndrome
Herrera, Aurelia Noda; Bruno, Alicia; Gonzalez, Carina; Moreno, Lorenzo; Sanabria, Hilda
2011-01-01
We present a research report on addition and subtraction conducted with Down syndrome students between the ages of 12 and 31. We interviewed a group of students with Down syndrome who executed algorithms and solved problems using specific materials and paper and pencil. The results show that students with Down syndrome progress through the same…
6. Adding and Subtracting Vectors: The Problem with the Arrow Representation
Heckler, Andrew F.; Scaife, Thomas M.
2015-01-01
A small number of studies have investigated student understanding of vector addition and subtraction in generic or introductory physics contexts, but in almost all cases the questions posed were in the vector arrow representation. In a series of experiments involving over 1000 students and several semesters, we investigated student understanding…
7. Fusion and subtraction post-processing in body MRI
Watson, Tom A.; Olsen, Oeystein E. [Great Ormond Street Hospital for Children NHS Foundation Trust, Department of Radiology, London (United Kingdom)
2014-09-02
Interpreting complex paediatric body MRI studies requires the integration of information from multiple sequences. Image processing software, some freely available, allows the radiologist to use simple and rapid post-processing techniques that may aid diagnosis. We demonstrate the use of fusion and subtraction post-processing techniques with examples from four areas of application: enterography, oncological imaging, musculoskeletal imaging and MR fistulography. (orig.)
8. Cutaneous Force Feedback as a Sensory Subtraction Technique in Haptics.
Prattichizzo, D; Pacchierotti, C; Rosati, G
2012-01-01
A novel sensory substitution technique is presented. Kinesthetic and cutaneous force feedback are substituted by cutaneous feedback (CF) only, provided by two wearable devices able to apply forces to the index finger and the thumb, while holding a handle during a teleoperation task. The force pattern, fed back to the user while using the cutaneous devices, is similar, in terms of intensity and area of application, to the cutaneous force pattern applied to the finger pad while interacting with a haptic device providing both cutaneous and kinesthetic force feedback. The pattern generated using the cutaneous devices can be thought as a subtraction between the complete haptic feedback (HF) and the kinesthetic part of it. For this reason, we refer to this approach as sensory subtraction instead of sensory substitution. A needle insertion scenario is considered to validate the approach. The haptic device is connected to a virtual environment simulating a needle insertion task. Experiments show that the perception of inserting a needle using the cutaneous-only force feedback is nearly indistinguishable from the one felt by the user while using both cutaneous and kinesthetic feedback. As most of the sensory substitution approaches, the proposed sensory subtraction technique also has the advantage of not suffering from stability issues of teleoperation systems due, for instance, to communication delays. Moreover, experiments show that the sensory subtraction technique outperforms sensory substitution with more conventional visual feedback (VF).
9. Children's Understanding of the Addition/Subtraction Complement Principle
Torbeyns, Joke; Peters, Greet; De Smedt, Bert; Ghesquière, Pol; Verschaffel, Lieven
2016-01-01
Background: In the last decades, children's understanding of mathematical principles has become an important research topic. Different from the commutativity and inversion principles, only few studies have focused on children's understanding of the addition/subtraction complement principle (if a - b = c, then c + b = a), mainly relying on verbal…
10. Image Segmentation in Video Sequences Using Modified Background Subtraction
D. W. Chinchkhede
2012-03-01
Full Text Available In computer vision, "Background subtraction" is a technique for finding moving objects in a video sequences for example vehicle driving on a freeway. For to detect non stationary (dynamic objects, it is necessary to subtracting current image from a time-averaged background image. There are various background subtraction algorithms for detecting moving vehicles or any moving object(s like pedestrians in urban traffic video sequences. A crude approximation to the task of classifying each pixel on the frame of current image, locate slow-moving objects or in poor image qualities of videos and distinguish shadows from moving objects by using modified background subtraction method. While classifying each pixel on the frame of the current image, it is to be detect the moving object at foreground and background conditional environment that we can classify each pixel using a model of how that pixellooks when it is part of video frame classes. A mixture of Gaussians classification model for each pixel using an unsupervised technique is an efficient, incremental version of Expectation Maximization (EM is used for the purpose. Unlike standard image-averaging approach, this method automatically updates the mixture component for each video frame class according to likelihood of membership; hence slowmoving objects and poor image quality of videos are also being handled perfectly. Our approach identifies and eliminates shadows much more effectively than other techniques like thresholding.
11. Subtraction-noise projection in gravitational-wave detector networks
Harms, Jan; Otto, Markus; Priess, Malte
2008-01-01
In this paper, we present a successful implementation of a subtraction-noise projection method into a simple, simulated data analysis pipeline of a gravitational-wave search. We investigate the problem to reveal a weak stochastic background signal which is covered by a strong foreground of compact-binary coalescences. The foreground which is estimated by matched filters, has to be subtracted from the data. Even an optimal analysis of foreground signals will leave subtraction noise due to estimation errors of template parameters which may corrupt the measurement of the background signal. The subtraction noise can be removed by a noise projection. We apply our analysis pipeline to the proposed future-generation space-borne Big Bang Observer (BBO) mission which seeks for a stochastic background of primordial GWs in the frequency range $\\sim 0.1-1$Hz covered by a foreground of black-hole and neutron-star binaries. Our analysis is based on a simulation code which provides a dynamical model of a time-delay interfe...
12. A method for dynamic subtraction MR imaging of the liver
Setti Ernesto
2006-06-01
Full Text Available Abstract Background Subtraction of Dynamic Contrast-Enhanced 3D Magnetic Resonance (DCE-MR volumes can result in images that depict and accurately characterize a variety of liver lesions. However, the diagnostic utility of subtraction images depends on the extent of co-registration between non-enhanced and enhanced volumes. Movement of liver structures during acquisition must be corrected prior to subtraction. Currently available methods are computer intensive. We report a new method for the dynamic subtraction of MR liver images that does not require excessive computer time. Methods Nineteen consecutive patients (median age 45 years; range 37–67 were evaluated by VIBE T1-weighted sequences (TR 5.2 ms, TE 2.6 ms, flip angle 20°, slice thickness 1.5 mm acquired before and 45s after contrast injection. Acquisition parameters were optimized for best portal system enhancement. Pre and post-contrast liver volumes were realigned using our 3D registration method which combines: (a rigid 3D translation using maximization of normalized mutual information (NMI, and (b fast 2D non-rigid registration which employs a complex discrete wavelet transform algorithm to maximize pixel phase correlation and perform multiresolution analysis. Registration performance was assessed quantitatively by NMI. Results The new registration procedure was able to realign liver structures in all 19 patients. NMI increased by about 8% after rigid registration (native vs. rigid registration 0.073 ± 0.031 vs. 0.078 ± 0.031, n.s., paired t-test and by a further 23% (0.096 ± 0.035 vs. 0.078 ± 0.031, p t-test after non-rigid realignment. The overall average NMI increase was 31%. Conclusion This new method for realigning dynamic contrast-enhanced 3D MR volumes of liver leads to subtraction images that enhance diagnostic possibilities for liver lesions.
13. A Quantitative and Standardized Method for the Evaluation of Choroidal Neovascularization Using MICRON III Fluorescein Angiograms in Rats.
Jonathan P Wigg
Full Text Available In-vivo imaging of choroidal neovascularization (CNV has been increasingly recognized as a valuable tool in the investigation of age-related macular degeneration (AMD in both clinical and basic research applications. Arguably the most widely utilised model replicating AMD is laser generated CNV by rupture of Bruch's membrane in rodents. Heretofore CNV evaluation via in-vivo imaging techniques has been hamstrung by a lack of appropriate rodent fundus camera and a non-standardised analysis method. The aim of this study was to establish a simple, quantifiable method of fluorescein fundus angiogram (FFA image analysis for CNV lesions.Laser was applied to 32 Brown Norway Rats; FFA images were taken using a rodent specific fundus camera (Micron III, Phoenix Laboratories over 3 weeks and compared to conventional ex-vivo CNV assessment. FFA images acquired with fluorescein administered by intraperitoneal injection and intravenous injection were compared and shown to greatly influence lesion properties. Utilising commonly used software packages, FFA images were assessed for CNV and chorioretinal burns lesion area by manually outlining the maximum border of each lesion and normalising against the optic nerve head. Net fluorescence above background and derived value of area corrected lesion intensity were calculated.CNV lesions of rats treated with anti-VEGF antibody were significantly smaller in normalised lesion area (p < 0.001 and fluorescent intensity (p < 0.001 than the PBS treated control two weeks post laser. The calculated area corrected lesion intensity was significantly smaller (p < 0.001 in anti-VEGF treated animals at 2 and 3 weeks post laser. The results obtained using FFA correlated with, and were confirmed by conventional lesion area measurements from isolectin stained choroidal flatmounts, where lesions of anti-VEGF treated rats were significantly smaller at 2 weeks (p = 0.049 and 3 weeks (p < 0.001 post laser.The presented method of in
14. Computerized analysis of coronary artery disease: Performance evaluation of segmentation and tracking of coronary arteries in CT angiograms
Zhou, Chuan, E-mail: [email protected]; Chan, Heang-Ping; Chughtai, Aamer; Kuriakose, Jean; Agarwal, Prachi; Kazerooni, Ella A.; Hadjiiski, Lubomir M.; Patel, Smita; Wei, Jun [Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109 (United States)
2014-08-15
Purpose: The authors are developing a computer-aided detection system to assist radiologists in analysis of coronary artery disease in coronary CT angiograms (cCTA). This study evaluated the accuracy of the authors’ coronary artery segmentation and tracking method which are the essential steps to define the search space for the detection of atherosclerotic plaques. Methods: The heart region in cCTA is segmented and the vascular structures are enhanced using the authors’ multiscale coronary artery response (MSCAR) method that performed 3D multiscale filtering and analysis of the eigenvalues of Hessian matrices. Starting from seed points at the origins of the left and right coronary arteries, a 3D rolling balloon region growing (RBG) method that adapts to the local vessel size segmented and tracked each of the coronary arteries and identifies the branches along the tracked vessels. The branches are queued and subsequently tracked until the queue is exhausted. With Institutional Review Board approval, 62 cCTA were collected retrospectively from the authors’ patient files. Three experienced cardiothoracic radiologists manually tracked and marked center points of the coronary arteries as reference standard following the 17-segment model that includes clinically significant coronary arteries. Two radiologists visually examined the computer-segmented vessels and marked the mistakenly tracked veins and noisy structures as false positives (FPs). For the 62 cases, the radiologists marked a total of 10191 center points on 865 visible coronary artery segments. Results: The computer-segmented vessels overlapped with 83.6% (8520/10191) of the center points. Relative to the 865 radiologist-marked segments, the sensitivity reached 91.9% (795/865) if a true positive is defined as a computer-segmented vessel that overlapped with at least 10% of the reference center points marked on the segment. When the overlap threshold is increased to 50% and 100%, the sensitivities were 86
15. Subtraction of Positive and Negative Numbers: The Difference and Completion Approaches with Chips
Flores, Alfinio
2008-01-01
Diverse contexts such as "take away," comparison," and "completion" give rise to subtraction problems. The take-away interpretation of subtraction has been explored using two-colored chips to help students understand addition and subtraction of integers. This article illustrates how the difference and completion (or missing addend) interpretations…
16. Robust Background Subtraction with Foreground Validation for Urban Traffic Video
Cheung, S S; Kamath, C
2004-01-15
Identifying moving objects in a video sequence is a fundamental and critical task in many computer-vision applications. Background subtraction techniques are commonly used to separate foreground moving objects from the background. Most background subtraction techniques assume a single rate of adaptation, which is inadequate for complex scenes such as a traffic intersection where objects are moving at different and varying speeds. In this paper, we propose a foreground validation algorithm that first builds a foreground mask using a slow-adapting Kalman filter, and then validates individual foreground pixels by a simple moving object model, built using both the foreground and background statistics as well as the frame difference. Ground-truth experiments with urban traffic sequences show that our proposed algorithm significantly improves upon results using only Kalman filter or frame-differencing, and outperforms other techniques based on mixture of Gaussians, median filter, and approximated media filter.
17. BBO and the Neutron-Star-Binary Subtraction Problem
Cutler, C
2006-01-01
The Big Bang Observer (BBO) is a proposed space-based gravitational-wave (GW) mission designed primarily to search for an inflation-generated GW background in the frequency range 0.1-1 Hz. The major astrophysical foreground in this range is gravitational radiation from inspiraling compact binaries. This foreground is expected to be much larger than the inflation-generated background, so to accomplish its main goal, BBO must be sensitive enough to identify and subtract out practically all such binaries in the observable universe. It is somewhat subtle to decide whether BBO's current baseline design is sufficiently sensitive for this task, since, at least initially, the dominant noise source impeding identification of any one binary is confusion noise from all the others. Here we present a self-consistent scheme for deciding whether BBO's baseline design is indeed adequate for subtracting out the binary foreground. We conclude that the current baseline should be sufficient. However if BBO's instrumental sensiti...
18. Spinal pedicle subtraction osteotomy for fixed sagittal imbalance patients.
Hyun, Seung-Jae; Kim, Yongjung J; Rhim, Seung-Chul
2013-11-16
In addressing spinal sagittal imbalance through a posterior approach, the surgeon now may choose from among a variety of osteotomy techniques. Posterior column osteotomies such as the facetectomy or Ponte or Smith-Petersen osteotomy provide the least correction, but can be used at multiple levels with minimal blood loss and a lower operative risk. Pedicle subtraction osteotomies provide nearly 3 times the per-level correction of Ponte/Smith-Petersen osteotomies; however, they carry increased technical demands, longer operative time, and greater blood loss and associated significant morbidity, including neurological injury. The literature focusing on pedicle subtraction osteotomy for fixed sagittal imbalance patients is reviewed. The long-term overall outcomes, surgical tips to reduce the complications and suggestions for their proper application are also provided.
19. ZAP -- Enhanced PCA Sky Subtraction for Integral Field Spectroscopy
Soto, Kurt T; Bacon, Roland; Richard, Johan; Conseil, Simon
2016-01-01
We introduce Zurich Atmosphere Purge (ZAP), an approach to sky subtraction based on principal component analysis (PCA) that we have developed for the Multi Unit Spectrographic Explorer (MUSE) integral field spectrograph. ZAP employs filtering and data segmentation to enhance the inherent capabilities of PCA for sky subtraction. Extensive testing shows that ZAP reduces sky emission residuals while robustly preserving the flux and line shapes of astronomical sources. The method works in a variety of observational situations from sparse fields with a low density of sources to filled fields in which the target source fills the field of view. With the inclusion of both of these situations the method is generally applicable to many different science cases and should also be useful for other instrumentation. ZAP is available for download at http://muse-vlt.eu/science/tools.
20. Direct Imaging of Exoplanets Without Background Subtraction: Implications for ELTs
Frazin, Richard A
2015-01-01
The ultra-high contrast capability required to form images of other solar systems is arguably the highest-profile challenge in astronomy today. The current high-contrast imaging efforts all require background subtraction to separate the planetary image from the image of the host star. Background estimation is difficult due to the presence of non-common path aberrations (NCPAs) that change with time. The only major source of information that is not being utilized by current efforts is the random encoding of the planetary image and the NCPAs by the atmosphere on millisecond time-scales. Here, a method that utilizes this information in order to avoid background subtraction altogether is proposed. This new paradigm will allow simultaneous estimation of the time-dependent NCPAs and the planetary image via rigorous statistical inference procedures. These procedures are fully compatible with other information sources, such as diurnal field rotation and spectral diversity. Given the open-ended nature of the backgroun...
1. An Adaptive Background Subtraction Method Based on Kernel Density Estimation
Mignon Park
2012-09-01
Full Text Available In this paper, a pixel-based background modeling method, which uses nonparametric kernel density estimation, is proposed. To reduce the burden of image storage, we modify the original KDE method by using the first frame to initialize it and update it subsequently at every frame by controlling the learning rate according to the situations. We apply an adaptive threshold method based on image changes to effectively subtract the dynamic backgrounds. The devised scheme allows the proposed method to automatically adapt to various environments and effectively extract the foreground. The method presented here exhibits good performance and is suitable for dynamic background environments. The algorithm is tested on various video sequences and compared with other state-of-the-art background subtraction methods so as to verify its performance.
2. Momentum-subtraction renormalization techniques in curved space-time
Foda, O.
1987-10-01
Momentum-subtraction techniques, specifically BPHZ and Zimmermann's Normal Product algorithm, are introduced as useful tools in the study of quantum field theories in the presence of background fields. In a model of a self-interacting massive scalar field, conformally coupled to a general asymptotically-flat curved space-time with a trivial topology, momentum-subtractions are shown to respect invariance under general coordinate transformations. As an illustration, general expressions for the trace anomalies are derived, and checked by explicit evaluation of the purely gravitational contributions in the free field theory limit. Furthermore, the trace of the renormalized energy-momentum tensor is shown to vanish at the Gell-Mann Low eigenvalue as it should.
3. Increasing entanglement between Gaussian states by coherent photon subtraction.
Ourjoumtsev, Alexei; Dantan, Aurélien; Tualle-Brouri, Rosa; Grangier, Philippe
2007-01-19
We experimentally demonstrate that the entanglement between Gaussian entangled states can be increased by non-Gaussian operations. Coherent subtraction of single photons from Gaussian quadrature-entangled light pulses, created by a nondegenerate parametric amplifier, produces delocalized states with negative Wigner functions and complex structures more entangled than the initial states in terms of negativity. The experimental results are in very good agreement with the theoretical predictions.
4. Increasing entanglement between Gaussian states by coherent photon subtraction
Ourjoumtsev, A; Tualle-Brouri, R; Grangier, P; Ourjoumtsev, Alexei; Dantan, Aurelien; Tualle-Brouri, Rosa; Grangier, Philippe
2006-01-01
We experimentally demonstrate that the entanglement between Gaussian entangled states can be increased by non-Gaussian operations. Coherent subtraction of single photons from Gaussian quadrature-entangled light pulses, created by a non-degenerate parametric amplifier, produces delocalized "Schroedinger kitten" states with complex negative Wigner functions, more entangled than the initial states in terms of negativity. The experimental results are in very good agreement with the theoretical predictions.
5. Manufacturability analysis to combine additive and subtractive processes
Kerbrat, Olivier; MOGNOL, Pascal; Hascoët, Jean-Yves
2010-01-01
International audience; Purpose - The purpose of this paper is to propose a methodology to estimate manufacturing complexity for both machining and layered manufacturing. The goal is to take into account manufacturing constraints at design stage in order to realize tools (dies and molds) by a combination of a subtractive process (high-speed machining) and an additive process (selective laser sintering). Design/methodology/approach - Manufacturability indexes are defined and calculated from th...
6. Subtraction Radiography for the Diagnosis of Bone Lesions in Dogs.
1984-05-31
Avail ander Journal of Periodontology Dist Special Ř 211 East Chicago Avenue Room 924 Chicago, IL 60611 Dear Sirs: I m submitting an original...research article titled "Subtraction Radiography for the Diagnosis of Bone Lesions in Dogs" solely to the Journal of Periodontology for review and... clinical practice in our area. 60-70 Kvp would have produced more contrast in the radiographic films used for the conventional technique, but likely
7. Manufacturability analysis to combine additive and subtractive processes
Kerbrat, Olivier; Mognol, Pascal; Hascoët, Jean-Yves
2010-01-01
International audience; Purpose - The purpose of this paper is to propose a methodology to estimate manufacturing complexity for both machining and layered manufacturing. The goal is to take into account manufacturing constraints at design stage in order to realize tools (dies and molds) by a combination of a subtractive process (high-speed machining) and an additive process (selective laser sintering). Design/methodology/approach - Manufacturability indexes are defined and calculated from th...
8. Subtractive Renormalization Group Invariance: Pionless EFT at NLO
Timóteo, Varese S.; Szpigel, Sérgio; Durães, Francisco O.
2010-11-01
We show some results concerning the renormalization group (RG) invariance of the nucleon-nucleon (NN) interaction in pionless effective field theory at next-to-leading order (NLO), using a non-relativistic Callan-Symanzik equation (NRCS) for the driving term of the Lippmann-Schwinger (LS) equation with three recursive subtractions. The phase-shifts obtained for the RG evolved potential are same as those for the original potential, apart from relative differences of order 10-15.
9. ROBUST TECHNIQUES FOR BACKGROUND SUBTRACTION IN URBAN TRAFFIC VIDEO
Kamath, C; Cheung, S S
2003-10-28
Identifying moving objects from a video sequence is a fundamental and critical task in many computer-vision applications. A common approach is to perform background subtraction, which identifies moving objects from the portion of a video frame that differs significantly from a background model. There are many challenges in developing a good background subtraction algorithm. First, it must be robust against changes in illumination. Second, it should avoid detecting non-stationary background objects such as swinging leaves, rain, snow, and shadow cast by moving objects. Finally, its internal background model should react quickly to changes in background such as starting and stopping of vehicles. In this paper, we compare various background subtraction algorithms for detecting moving vehicles and pedestrians in urban traffic video sequences. We consider approaches varying from simple techniques such as frame differencing and adaptive median filtering, to more sophisticated probabilistic modeling techniques. While complicated techniques often produce superior performance, our experiments show that simple techniques such as adaptive median filtering can produce good results with much lower computational complexity.
10. N-jettiness Subtractions for NNLO QCD Calculations
Gaunt, Jonathan; Tackmann, Frank J; Walsh, Jonathan R
2015-01-01
We present a subtraction method utilizing the N-jettiness observable, Tau_N, to perform QCD calculations for arbitrary processes at next-to-next-to-leading order (NNLO). Our method employs soft-collinear effective theory (SCET) to determine the IR singular contributions of N-jet cross sections for Tau_N -> 0, and uses these to construct suitable Tau_N-subtractions. The construction is systematic and economic, due to being based on a physical observable. The resulting NNLO calculation is fully differential and in a form directly suitable for combining with resummation and parton showers. We explain in detail the application to processes with an arbitrary number of massless partons at lepton and hadron colliders together with the required external inputs in the form of QCD amplitudes and lower-order calculations. We provide explicit expressions for the Tau_N-subtractions at NLO and NNLO. The required ingredients are fully known at NLO, and at NNLO for processes with two external QCD partons. The remaining NNLO ...
11. Addition and subtraction in wild New Zealand robins.
Garland, Alexis; Low, Jason
2014-11-01
This experiment aimed to investigate proto-arithmetic ability in a wild population of New Zealand robins. We investigated numerical competence from the context of computation: behavioural responses to arithmetic operations over small numbers of prey objects (mealworms). Robins' behavioural responses (such as search time) to the simple addition and subtraction problems presented in a Violation of Expectancy (VoE) paradigm were measured. Either a congruent (expected) or incongruent (unexpected) quantity of food items were hidden in a trap door out of view of the subject. Within view of the subject, a quantity of items were added into (and in some cases subtracted from) the apparatus which was either the same as that hidden, or different. Robins were then allowed them to find a quantity that either preserved or violated addition and subtraction outcomes. Robins searched around the apparatus longer when presented with an incongruent scenario violating arithmetic rules, demonstrating potential proto-arithmetic awareness of changes in prey quantity. This article is part of a Special Issue entitled: Cognition in the wild.
12. Genome subtraction for novel target definition in Salmonella typhi.
Rathi, Bhawna; Sarangi, Aditya N; Trivedi, Nidhi
2009-10-11
Large genomic sequencing projects of pathogens as well as human genome leads to immense genomic and proteomic data which would be very beneficial for the novel target identification in pathogens. Subtractive genomic approach is one of the most useful strategies helpful in identification of potential targets. The approach works by subtracting the genes or proteins homologous to both host and the pathogen and identify those set of gene or proteins which are essential for the pathogen and are exclusively present in the pathogen. Subtractive genomic approach is employed to identify novel target in salmonella typhi. The pathogen has 4718 proteins out of which 300 are found to be essential (" indispensable to support cellular life") in the pathogen with no human homolog. Metabolic pathway analyses of these 300 essential proteins revealed that 149 proteins are exclusively involved in several metabolic pathway of S. typhi. 8 metabolic pathways are found to be present exclusively in the pathogen comprising of 27 enzymes unique to the pathogen. Thus, these 27 proteins may serve as prospective drug targets. Sub-cellular localization prediction of the 300 essential proteins was done which reveals that 11 proteins lie on the outer membrane of the pathogen which could be probable vaccine candidates.
13. An improved dark-object subtraction technique for atmospheric scattering correction of multispectral data
Chavez, P.S.
1988-01-01
Digital analysis of remotely sensed data has become an important component of many earth-science studies. These data are often processed through a set of preprocessing or "clean-up" routines that includes a correction for atmospheric scattering, often called haze. Various methods to correct or remove the additive haze component have been developed, including the widely used dark-object subtraction technique. A problem with most of these methods is that the haze values for each spectral band are selected independently. This can create problems because atmospheric scattering is highly wavelength-dependent in the visible part of the electromagnetic spectrum and the scattering values are correlated with each other. Therefore, multispectral data such as from the Landsat Thematic Mapper and Multispectral Scanner must be corrected with haze values that are spectral band dependent. An improved dark-object subtraction technique is demonstrated that allows the user to select a relative atmospheric scattering model to predict the haze values for all the spectral bands from a selected starting band haze value. The improved method normalizes the predicted haze values for the different gain and offset parameters used by the imaging system. Examples of haze value differences between the old and improved methods for Thematic Mapper Bands 1, 2, 3, 4, 5, and 7 are 40.0, 13.0, 12.0, 8.0, 5.0, and 2.0 vs. 40.0, 13.2, 8.9, 4.9, 16.7, and 3.3, respectively, using a relative scattering model of a clear atmosphere. In one Landsat multispectral scanner image the haze value differences for Bands 4, 5, 6, and 7 were 30.0, 50.0, 50.0, and 40.0 for the old method vs. 30.0, 34.4, 43.6, and 6.4 for the new method using a relative scattering model of a hazy atmosphere. ?? 1988.
14. Temporal subtraction contrast-enhanced dedicated breast CT
Gazi, Peymon M.; Aminololama-Shakeri, Shadi; Yang, Kai; Boone, John M.
2016-09-01
The development of a framework of deformable image registration and segmentation for the purpose of temporal subtraction contrast-enhanced breast CT is described. An iterative histogram-based two-means clustering method was used for the segmentation. Dedicated breast CT images were segmented into background (air), adipose, fibroglandular and skin components. Fibroglandular tissue was classified as either normal or contrast-enhanced then divided into tiers for the purpose of categorizing degrees of contrast enhancement. A variant of the Demons deformable registration algorithm, intensity difference adaptive Demons (IDAD), was developed to correct for the large deformation forces that stemmed from contrast enhancement. In this application, the accuracy of the proposed method was evaluated in both mathematically-simulated and physically-acquired phantom images. Clinical usage and accuracy of the temporal subtraction framework was demonstrated using contrast-enhanced breast CT datasets from five patients. Registration performance was quantified using normalized cross correlation (NCC), symmetric uncertainty coefficient, normalized mutual information (NMI), mean square error (MSE) and target registration error (TRE). The proposed method outperformed conventional affine and other Demons variations in contrast enhanced breast CT image registration. In simulation studies, IDAD exhibited improvement in MSE (0-16%), NCC (0-6%), NMI (0-13%) and TRE (0-34%) compared to the conventional Demons approaches, depending on the size and intensity of the enhancing lesion. As lesion size and contrast enhancement levels increased, so did the improvement. The drop in the correlation between the pre- and post-contrast images for the largest enhancement levels in phantom studies is less than 1.2% (150 Hounsfield units). Registration error, measured by TRE, shows only submillimeter mismatches between the concordant anatomical target points in all patient studies. The algorithm was
15. Non-contrast-enhanced MR angiography in critical limb ischemia: performance of quiescent-interval single-shot (QISS) and TSE-based subtraction techniques.
Altaha, Mustafa A; Jaskolka, Jeffrey D; Tan, Kongteng; Rick, Manuela; Schmitt, Peter; Menezes, Ravi J; Wintersperger, Bernd J
2017-03-01
The aim of this study was to evaluate diagnostic performance of non-contrast-enhanced 2D quiescent-interval single-shot (QISS) and 3D turbo spin-echo (TSE)-based subtraction magnetic resonance angiography (MRA) in the assessment of peripheral arteries in patients with critical limb ischemia (CLI). Nineteen consecutive patients (74 % male, 72.8 ± 9.9 years) with CLI underwent 2D QISS and 3D TSE-based subtraction MRA at 1.5 T. Axial-overlapping QISS MRA (3 mm/2 mm; 1 × 1 mm(2)) covered from the toes to the aortic bifurcation while coronal 3D TSE-based subtraction MRA (1.3 × 1.2 × 1.3 mm(3)) was restricted to the calf only. MRA data sets (two readers) were evaluated for stenosis (≥50 %) and image quality. Results were compared with digital subtraction angiography (DSA). Two hundred and sixty-seven (267) segments were available for MRA-DSA comparison, with a prevalence of stenosis ≥50 % of 41.9 %. QISS MRA was rated as good to excellent in 79.5-96.0 % of segments without any nondiagnostic segments; 89.8-96.1 % of segments in 3D TSE-based subtraction MRA were rated as nondiagnostic or poor. QISS MRA sensitivities and specificities (segmental) were 92 % and 95 %, respectively, for reader one and 81-97 % for reader two. Due to poor image quality of 3D TSE-based subtraction MRA, diagnostic performance measures were not calculated. QISS MRA demonstrates excellent diagnostic performance and higher robustness than 3D TSE-based subtraction MRA in the challenging patient population with CLI. • QISS MRA allows reliable diagnosis of peripheral artery stenosis in critical limb ischemia. • Robustness of TSE-based subtraction MRA is limited in critical limb ischemia. • QISS MRA allows robust therapy planning in PAD patients with resting leg pain.
16. Reconstruction of Intima and Adventitia Models into a State Undeformed by a Catheter by Using CT, IVUS, and Biplane X-Ray Angiogram Images
Jinwon Son
2017-01-01
Full Text Available The number of studies on blood flow analysis using fluid-structure interaction (FSI analysis is increasing. Though a 3D blood vessel model that includes intima and adventitia is required for FSI analysis, there are difficulties in generating it using only one type of medical imaging. In this paper, we propose a 3D modeling method for accurate FSI analysis. An intravascular ultrasound (IVUS image is used with biplane X-ray angiogram images to calculate the position and orientation of the blood vessel. However, these images show that the blood vessel is deformed by the catheter inserted into the blood vessel for IVUS imaging. To eliminate such deformation, a CT image was added and the two models were registered. First, a 3D model of the undeformed intima was generated using a CT image. In the second stage, a model of intima and adventitia deformed by the catheter was generated by combining the IVUS image and the X-ray angiogram images. A 3D model of intima and adventitia with the deformation caused by insertion of the catheter eliminated was generated by matching these 3D blood vessel models in different states. In addition, a 3D blood vessel model including bifurcation was generated using the proposed method.
17. Digital X-ray Imaging in Dentistry
Kim, Eun Kyung [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Dankook University, Yongin (Korea, Republic of)
1999-08-15
18. Adding and subtracting vectors: The problem with the arrow representation
Andrew F. Heckler
2015-01-01
Full Text Available A small number of studies have investigated student understanding of vector addition and subtraction in generic or introductory physics contexts, but in almost all cases the questions posed were in the vector arrow representation. In a series of experiments involving over 1000 students and several semesters, we investigated student understanding of vector addition and subtraction in both the arrow and algebraic notation (using i[over ^], j[over ^], k[over ^] in generic mathematical and physics contexts. First, we replicated a number of previous findings of student difficulties in the arrow format and discovered several additional difficulties, including the finding that different relative arrow orientations can prompt different solution paths and different kinds of mistakes, which suggests that students need to practice with a variety of relative orientations. Most importantly, we found that average performance in the ijk format was typically excellent and often much better than performance in the arrow format in either the generic or physics contexts. Further, while we find that the arrow format tends to prompt students to a more physically intuitive solution path, we also find that, when prompted, student solutions in the ijk format also display significant physical insights into the problem. We also find a hierarchy in correct answering between the two formats, with correct answering in the ijk format being more fundamental than for the arrow format. Overall, the results suggest that many student difficulties with these simple vector problems lie with the arrow representation itself. For instruction, these results imply that introducing the ijk notation (or some equivalent with the arrow notation concurrently may be a very useful way to improve student performance as well as help students to learn physics concepts involving vector addition and subtraction.
19. Leading Guard Digits in Finite-Precision Redundant Representations
Muller, Jean-Michel; Kornerup, Peter
2006-01-01
Redundant number representations are generally used to allow constant time additions, based on the fact that only bounded carry-ripples take place. But, carries may ripple out into positions which may not be needed to represent the final value of the result and, thus, a certain amount of leading guard digits are needed to correctly determine the result. Also, when cancellation during subtractions occurs, there may be nonzero digits in positions not needed to represent the result of the calcul...
20. Intermediate Palomar Transient Factory: Realtime Image Subtraction Pipeline
Cao, Yi; Kasliwal, Mansi M
2016-01-01
A fast-turnaround pipeline for realtime data reduction plays an essential role in discovering and permitting follow-up observations to young supernovae and fast-evolving transients in modern time-domain surveys. In this paper, we present the realtime image subtraction pipeline in the intermediate Palomar Transient Factory. By using high-performance computing, efficient database, and machine learning algorithms, this pipeline manages to reliably deliver transient candidates within ten minutes of images being taken. Our experience in using high performance computing resources to process big data in astronomy serves as a trailblazer to dealing with data from large-scale time-domain facilities in near future.
1. Addition and subtraction by students with Down syndrome
Noda Herrera, Aurelia; Bruno, Alicia; González, Carina; Moreno, Lorenzo; Sanabria, Hilda
2011-01-01
We present a research report on addition and subtraction conducted with Down syndrome students between the ages of 12 and 31. We interviewed a group of students with Down syndrome who executed algorithms and solved problems using specific materials and paper and pencil. The results show that students with Down syndrome progress through the same procedural levels as those without disabilities though they have difficulties in reaching the most abstract level (numerical facts). The use of fingers or concrete representations (balls) appears as a fundamental process among these students. As for errors, these vary widely depending on the students, and can be attributed mostly to an incomplete knowledge of the decimal number system.
2. Black hole entropy thermodynamics, statistical-mechanics and subtraction procedure
Frolov, V P; Zelnikov, A I
1996-01-01
The thermodynamical one-loop entropy S^{TD} of a two-dimensional black hole in thermal equilibrium with the massless quantum gas is calculated. It is shown that S^{TD} includes the Bekenstein-Hawking entropy, evaluated for the quantum corrected geometry, and the finite difference of statistical mechanical entropies -Tr\\hat{\\rho}\\ln\\hat{\\rho} for the gas on the black hole and Rindler spaces. This result demonstrates in an explicit form that the relation between thermodynamical and statistical-mechanical entropies of a black hole is non-trivial and requires special subtraction procedure.
3. Subtracting Technique of Baselines for Capillary Electrophoresis Signals
WANG Ying; MO Jin-yuan; CHEN Zuan-guang; GAO Yan
2004-01-01
The drifting baselines of capillary electrophoresis affect the veracity of analysis greatly. This paper presents Threshold Fitting Technique(TFT) so as to subtract the baselines from the original signals and emendate the signals. In TFT, wav elet and curve fitting technique are applied synthetically, thresholds are decided by the computer automatically. Many experiments of signal processing indicate that TFT is simple for being used, there are few man-induced factors, and the results are satisfactory. TFT can be applied for noisy signals without any pre-processing.
4. [Ziedses des Plantes: inventor of planigraphy and subtraction].
van Gijn, Jan; Gijselhart, Joost P
2011-01-01
Bernard George Ziedses des Plantes (1902-1993) trained in Utrecht, the Netherlands, as specialist in nervous diseases, but his lifelong passion was to improve X-ray imaging of living tissues. In the 1930s he not only built the first machine for planigraphy, in which the X-ray tube and the film moved together around the plane of interest, but he also designed the subtraction method to improve images after injection of contrast agents. Eventually a full-time radiologist, he also developed the 'somersault' technique of ventriculography and pioneered isotope scintigraphy.
5. Comparing Background Subtraction Algorithms and Method of Car Counting
Thakur, Gautam S; Hui, Pan; Helmy, Ahmed
2012-01-01
In this paper, we compare various image background subtraction algorithms with the ground truth of cars counted. We have given a sample of thousand images, which are the snap shots of current traffic as records at various intersections and highways. We have also counted an approximate number of cars that are visible in these images. In order to ascertain the accuracy of algorithms to be used for the processing of million images, we compare them on many metrics that includes (i) Scalability (ii) Accuracy (iii) Processing time.
6. Speech enhancement by array crosstalk resistant ANC and spectrum subtraction
ZENG Qingning; OUYANG Shan
2008-01-01
Microphone array-based speech enhancement has great importance for speech com-munications and speech recognition. To reduce the aperture of the microphone array and to increase the effect of the speech enhancement will greatly broaden the application areas of the microphone array. An array crosstalk resistant adaptive noise cancellation method is therefore presented. And then an improved spectral subtraction algorithm is further cascaded to obtain better enhancement results. Theoretic analysis and experiments indicate that the proposed scheme needs only a very small microphone array while it simultaneously achieves a higher SNR improvement. Besides, the proposed scheme can be used in many noisy environments and is easy for real-time implementation.
7. Development of a voxel-matching technique for substantial reduction of subtraction artifacts in temporal subtraction images obtained from thoracic MDCT.
Itai, Yoshinori; Kim, Hyoungseop; Ishikawa, Seiji; Katsuragawa, Shigehiko; Doi, Kunio
2010-02-01
A temporal subtraction image, which is obtained by subtraction of a previous image from a current one, can be used for enhancing interval changes (such as formation of new lesions and changes in existing abnormalities) on medical images by removing most of the normal structures. However, subtraction artifacts are commonly included in temporal subtraction images obtained from thoracic computed tomography and thus tend to reduce its effectiveness in the detection of pulmonary nodules. In this study, we developed a new method for substantially removing the artifacts on temporal subtraction images of lungs obtained from multiple-detector computed tomography (MDCT) by using a voxel-matching technique. Our new method was examined on 20 clinical cases with MDCT images. With this technique, the voxel value in a warped (or nonwarped) previous image is replaced by a voxel value within a kernel, such as a small cube centered at a given location, which would be closest (identical or nearly equal) to the voxel value in the corresponding location in the current image. With the voxel-matching technique, the correspondence not only between the structures but also between the voxel values in the current and the previous images is determined. To evaluate the usefulness of the voxel-matching technique for removal of subtraction artifacts, the magnitude of artifacts remaining in the temporal subtraction images was examined by use of the full width at half maximum and the sum of a histogram of voxel values, which may indicate the average contrast and the total amount, respectively, of subtraction artifacts. With our new method, subtraction artifacts due to normal structures such as blood vessels were substantially removed on temporal subtraction images. This computerized method can enhance lung nodules on chest MDCT images without disturbing misregistration artifacts.
8. Temporal Subtraction of Digital Breast Tomosynthesis Images for Improved Mass Detection
2007-10-01
number of low-dose cone-beam projection images", Medical Physics 30 (3), 365 (2003). 9 E.A. Sickles, W.N. Weber, H.B. Galvin, S.H. Ominsky, and R.A...temporal pairs of mammograms for interval change analysis--local affine transformation for improved localization", Medical Physics 28 (6), 1070 (2001...aided classification of malignant and benign breast masses", Medical Physics 28 (11), 2309 (2001). 25 K. Marias, C. Behrenbruch, S. Parbhoo, A
9. Comparative evaluation of 64-slice CT angiography and digital subtraction angiography in assessing the cervicocranial vasculature
Randolf Klingebiel
2008-08-01
Full Text Available Randolf Klingebiel1, Max Kentenich3, Hans-Christian Bauknecht3, Florian Masuhr2, Eberhard Siebert1, Markus Busch2, Georg Bohner11Department of Neuroradiology, 2Department of Neurology, 3Department of Radiology, Charité Universitary Medicine Berlin, GermanyBackground: Noninvasive 64-slice computed tomography angiography (64-MSCTA closely approximates conventional catheter angiography (DSA in terms of detail resolution. Objective: Retrospective evaluation of cervicocranial (cc 64-MSCTA in comparison with DSA in patients with presumptive cc vascular disorders.Material and methods: Twenty-four 64-MSCTA studies (32 mm detector width, slice thickness 0.5 mm, 120 kv, 150 mAs, pitch 0.75 of patients with presumptive cc vascular pathology (13 men, 11 women, mean age 38.3 ± 11.3 yrs, range 19–54 yrs were assessed in comparison with DSA studies without abnormal findings in age-matched patients (11 men, 13 women, mean age 39.7 ± 11.9 yrs, range 18–54 yrs. Study readings were performed in a blinded manner by two neuroradiologists with respect to image quality and assessibility of various cc vascular segments by using a five-point scale. Radiation exposure was calculated for 64-MSCTA.Results: Each reader assessed 384/528 different vessel segments (64-MSCTA/DSA. Superior image quality was attributed to DSA with respect to the C1 ICA–C6 ICA, A3 ACA, and P3 PCA segments as well the AICA and SCA. 64-MSCTA was scored superior for C7 ICA and V4 VA segments. A significantly increased number of nonassessable V2- and V3 VA segments in DSA studies was noted. The effective dose for 64-MSCTA amounted to 2.2 mSv.Conclusions: 64-MSCTA provides near-equivalent diagnostic information of the cc vasculature as compared with DSA. According to our results, DSA should be considered primarily when peripheral vessels (A3/P3 or ICA segments close to the skull base (C2-5 are of interest, such as in primary angiitis or stenoocclusive ICA disease, respectively.Keywords: CT-angiography, CNS, angiography
10. Value of digital subtraction angiography for the evaluation of peripheral arteriovenous shunts in patients with haemodialysis
Beil, D.; Bolsinger, G.; Deininger, H.K.
1987-02-01
Direct and indirect examination of arteriovenous shunts was performed in 50 patients undergoing haemodialysis. The various methods of puncture of the vessels, the indications and the limitations of DSA are considered. The advantages of direct puncture of the arteriovenous shunt are emphasised. Puncture of the venous branch is almost without risk and allows immediate diagnosis. Only in a very few cases it will be necessary to perform the risky puncture of the arterial branch or the time-consuming central venous injection of a bolus of the contrast medium.
11. Transvenous digital subtraction angiography (DSA) of the thoracic aorta after surgical correction of aortic coarctation
Arlart, I.P.; Hamann, H.; Stenz, R.
1985-01-01
25 patients (normotensive n = 19, hypertensive n = 6) underwent DSA control following corrective surgery of a coarcatation of the thoracic aorta to exclude vascular complications. Simultaneously pressure gradients were determined between upper and lower extremities using the doppler-sonography. DSA was diagnostic in all patients. 2 cases showed a patch-dependent dilatation, in 1 case an anastomotic aneurysm could be demonstrated. In 6 patients with hypoplastic aortic arch and 2 patients with a slight reduction of the diameter in the anastomotic region a pathological pressure-gradient was measured. In these patients the ratio of aortic arch rsp. anastomosis/descending aorta was reduced in diameter (< 0,66) and area (< 44). Hypertension could not be related to pressure gradients or vascular disorders.
12. The analysis of cerebro-vascular circulation time using digital subtraction angiography (DSA)
Han, D. G.; Kim, D. H.; Lee, H. K.; Kwon, K. H.; Kim, K. J. [Soonchunhyang University College of Medicine, Asan (Korea, Republic of)
1986-10-15
We analyzed the cerebral arterio-venous circulation time of 141 cases of cranial DSA in 136 patients, for the assessment of cerebral circulatory dynamics. IV-DSA was 111 cases, IA-DSA 30 cases. The results were as follows: 1. There was no significant difference in arterio-venous circulation time between IA-DSA and IV-DSA, if the disease pattern was not considered (P > 0.1). 2. Prolongation of arterio-venous circulation time was noted in the cases of cerebral (cerebellar) hemorrhage, subarachnoid hemorrhage, intracranial hematoma, brain abscess, acute stage of cerebra-vascular occlusive disease, acute stage of postoperative follow up, and acute stage of cerebral contusion (p > 0.05). 3. Compared the chronic stage of cerebra-vascular occlusive disease, postoperative follow up, and cerebral contusion with acute stage, significant decrement of arterio-venous circulation time was resulted (p > 0.05). 4. DSA was a useful modality for the assessment of circulatory dynamics, including measurement of arterio-venous circulation time.
13. Quantitative digital subtraction radiography for assessment of bone density changes following periodontal guided tissue regeneration
Christgau, M; Wenzel, A; Hiller, K A; Schmalz, G
1996-01-01
...). Twelve patients with 30 intrabony lesions and 16 furcation defects took part. Standardized radiographic and clinical examinations were carried out immediately before and then 5 and 13 months after surgery...
14. Evaluation of renal donors and recipients using intravenous digital subtraction angiography
Choi, Deuk Lin; Kim, Ki Jeung [Soonchunhyang Medical College, Seoul (Korea, Republic of)
1986-04-15
Renal IV DSA was applied to evaluate 15 potential renal donors and 14 examinations of 12 renal allograft recipients. We evaluate the angiographic acute or chronic rejection, alteration of renal size after transplantation, excretion time of the contrast media and pre, post DSA serum creatinine level. DSA is a safe, easily performed, outpatient procedure and useful in evaluation and distinguishing status of surgical anastomosis, intrarenal vasculatures, arterial exception time and rejection phenomenon.
15. Nested soft-collinear subtractions in NNLO QCD computations
Caola, Fabrizio [CERN, Theoretical Physics Department, Geneva (Switzerland); IPPP, Durham University, Durham (United Kingdom); Melnikov, Kirill; Roentsch, Raoul [Institute for Theoretical Particle Physics, KIT, Karlsruhe (Germany)
2017-04-15
We discuss a modification of the next-to-next-to-leading order (NNLO) subtraction scheme based on the residue-improved sector decomposition that reduces the number of double-real emission sectors from five to four. In particular, a sector where energies and angles of unresolved particles vanish in a correlated fashion is redundant and can be discarded. This simple observation allows us to formulate a transparent iterative subtraction procedure for double-real emission contributions, to demonstrate the cancellation of soft and collinear singularities in an explicit and (almost) process-independent way and to write the result of a NNLO calculation in terms of quantities that can be computed in four space-time dimensions. We illustrate this procedure explicitly in the simple case of O(α{sub s}{sup 2}) gluonic corrections to the Drell-Yan process of q anti q annihilation into a lepton pair. We show that this framework leads to fast and numerically stable computation of QCD corrections. (orig.)
16. Background Subtraction Based on Three-Dimensional Discrete Wavelet Transform.
Han, Guang; Wang, Jinkuan; Cai, Xi
2016-03-30
Background subtraction without a separate training phase has become a critical task, because a sufficiently long and clean training sequence is usually unavailable, and people generally thirst for immediate detection results from the first frame of a video. Without a training phase, we propose a background subtraction method based on three-dimensional (3D) discrete wavelet transform (DWT). Static backgrounds with few variations along the time axis are characterized by intensity temporal consistency in the 3D space-time domain and, hence, correspond to low-frequency components in the 3D frequency domain. Enlightened by this, we eliminate low-frequency components that correspond to static backgrounds using the 3D DWT in order to extract moving objects. Owing to the multiscale analysis property of the 3D DWT, the elimination of low-frequency components in sub-bands of the 3D DWT is equivalent to performing a pyramidal 3D filter. This 3D filter brings advantages to our method in reserving the inner parts of detected objects and reducing the ringing around object boundaries. Moreover, we make use of wavelet shrinkage to remove disturbance of intensity temporal consistency and introduce an adaptive threshold based on the entropy of the histogram to obtain optimal detection results. Experimental results show that our method works effectively in situations lacking training opportunities and outperforms several popular techniques.
17. Quasi-Normal Modes for Subtracted Rotating and Magnetised Geometries
Cvetic, M; Saleem, Z H
2014-01-01
We obtain explicit separable solutions of the wave equation of massless minimally coupled scalar fields in the subtracted geometry of four-dimensional rotating and Melvin (magnetised) four-charge black holes of the STU model, a consistent truncation of maximally supersymmetric supergravity with four types of electromagnetic fields. These backgrounds possess a hidden SL(2,R) x SL(2,R) x SO(3) symmetry and faithfully model the near horizon geometry of these black holes, but locate them in a confining asymptotically conical box. For each subtracted geometry we obtain two branches of quasi-normal modes, given in terms of hypergeometric functions and spherical harmonics. One branch is over-damped and the other under-damped and they exhibit rotational splitting. No black hole bomb is possible because the Killing field which co-rotates with the horizon is everywhere timelike outside the black hole. A five-dimensional lift of these geometries is given locally by the product of a BTZ black hole with a a two-sphere. Th...
18. Infinite S-expansion with ideal subtraction and some applications
Peñafiel, D. M.; Ravera, L.
2017-08-01
According to the literature, the S-expansion procedure involving a finite semigroup is valid no matter what the structure of the original Lie (super)algebra is; however, when something about the structure of the starting (super)algebra is known and when certain particular conditions are met, the S-expansion method (with its features of resonance and reduction) is able not only to lead to several kinds of expanded (super)algebras but also to reproduce the effects of the standard as well as the generalized Inönü-Wigner contraction. In the present paper, we propose a new prescription for S-expansion, involving an infinite abelian semigroup S(∞ ) and the subtraction of an infinite ideal subalgebra. We show that the subtraction of the infinite ideal subalgebra corresponds to a reduction. Our approach is a generalization of the finite S-expansion procedure presented in the literature, and it offers an alternative view of the generalized Inönü-Wigner contraction. We then show how to write the invariant tensors of the target (super)algebras in terms of those of the starting ones in the infinite S-expansion context presented in this work. We also give some interesting examples of application on algebras and superalgebras.
19. Digital Preservation.
Yakel, Elizabeth
2001-01-01
Reviews research on digital preservation issues, including born-digital and digitally recreated documents. Discusses electronic records research; metadata and other standards; electronic mail; Web-based documents; moving images media; selection of materials for digitization, including primary sources; administrative issues; media stability…
20. Restenosis in coronary bare metal stents. Importance of time to follow-up: a comparison of coronary angiograms 6 months and 4 years after implantation
Jørgensen, Erik; Helqvist, Steffen; Kløvgaard, Lene
2008-01-01
Objectives. Angiographic late lumen loss measured 6 to 9 month after bare metal stent implantation in the coronary arteries is a validated restenosis parameter. Design. We performed a second angiographic follow-up after 4 years in event free survivors from the DANSTENT trial cohort. Results....... Quantitative comparison of paired coronary angiograms at 6 months and 4 years showed a reduction of late loss from 0.68+/-0.52mm to 0.42 (+/-0.52) (mean difference 0.26 (0.17 to 0.36), p...% confidence interval: -0.34mm to -0.14mm, pstenosis decreased from 24.8+/-14.2% to 18.6+/-9.3% (mean difference 6.16%, 95% confidence interval: 2.82 to 9.48%, p=0.0006). This observed spontaneous decrease of instent restenosis corresponds to a 19% increase of minimal cross...
1. Surgical treatment of moyamoya disease: operative technique for encephalo-duro-arterio-myo-synangiosis, its follow-up, clinical results, and angiograms.
Kinugasa, K; Mandai, S; Kamata, I; Sugiu, K; Ohmoto, T
1993-04-01
Moyamoya syndrome is defined as the development of collateral anastomosis pathways at the base of the brain, associated with chronic progressive stenosis of the carotid fork. Both reconstructive vascular surgery and conservative strategies are used to treat this syndrome, but the latter cannot prevent the disease from progressing. We describe the procedure of encephalo-duro-arterio-myo-synangiosis (EDAMS), and report the results in 17 patients (28 sides) who underwent EDAMS. The clinical symptoms of moyamoya disease include transient ischemic attacks, reversible ischemic neurological deficits, stroke, seizures, Gerstmann's syndrome, involuntary movements, or mental retardation resulting from the lack of cerebral blood flow. The clinical results of EDAMS were poor in one patient, fair in two, good in five, excellent in eight, and fair on one side and excellent on the other side in one patient. Postoperative angiograms showed widespread collateral circulation on the ischemic brain surface in patients undergoing EDAMS.
2. Once and twice subtracted dispersion relations in the analysis of pi pi amplitudes
Kaminski, R; Peláez, J R; Ynduráin, F J
2009-01-01
Once and twice subtracted crossing symmetric dispersion relations applied to $\\pi\\pi \\to \\pi\\pi$ scattering data are analyzed and compared. Both sets of dispersion relations can be used to test the $\\pi\\pi$ amplitudes in low partial waves up to about 1 GeV. We show how once subtracted dispersion relations can provide stronger constraints for $\\pi\\pi$ amplitudes than twice subtracted ones in the 400 to 1100 MeV range, given the same experimental input.
3. A level-set method for pathology segmentation in fluorescein angiograms and en face retinal images of patients with age-related macular degeneration
Mohammad, Fatimah; Ansari, Rashid; Shahidi, Mahnaz
2013-03-01
The visibility and continuity of the inner segment outer segment (ISOS) junction layer of the photoreceptors on spectral domain optical coherence tomography images is known to be related to visual acuity in patients with age-related macular degeneration (AMD). Automatic detection and segmentation of lesions and pathologies in retinal images is crucial for the screening, diagnosis, and follow-up of patients with retinal diseases. One of the challenges of using the classical level-set algorithms for segmentation involves the placement of the initial contour. Manually defining the contour or randomly placing it in the image may lead to segmentation of erroneous structures. It is important to be able to automatically define the contour by using information provided by image features. We explored a level-set method which is based on the classical Chan-Vese model and which utilizes image feature information for automatic contour placement for the segmentation of pathologies in fluorescein angiograms and en face retinal images of the ISOS layer. This was accomplished by exploiting a priori knowledge of the shape and intensity distribution allowing the use of projection profiles to detect the presence of pathologies that are characterized by intensity differences with surrounding areas in retinal images. We first tested our method by applying it to fluorescein angiograms. We then applied our method to en face retinal images of patients with AMD. The experimental results included demonstrate that the proposed method provided a quick and improved outcome as compared to the classical Chan-Vese method in which the initial contour is randomly placed, thus indicating the potential to provide a more accurate and detailed view of changes in pathologies due to disease progression and treatment.
4. The association between symbolic and nonsymbolic numerical magnitude processing and mental versus algorithmic subtraction in adults.
Linsen, Sarah; Torbeyns, Joke; Verschaffel, Lieven; Reynvoet, Bert; De Smedt, Bert
2016-03-01
There are two well-known computation methods for solving multi-digit subtraction items, namely mental and algorithmic computation. It has been contended that mental and algorithmic computation differentially rely on numerical magnitude processing, an assumption that has already been examined in children, but not yet in adults. Therefore, in this study, we examined how numerical magnitude processing was associated with mental and algorithmic computation, and whether this association with numerical magnitude processing was different for mental versus algorithmic computation. We also investigated whether the association between numerical magnitude processing and mental and algorithmic computation differed for measures of symbolic versus nonsymbolic numerical magnitude processing. Results showed that symbolic, and not nonsymbolic, numerical magnitude processing was associated with mental computation, but not with algorithmic computation. Additional analyses showed, however, that the size of this association with symbolic numerical magnitude processing was not significantly different for mental and algorithmic computation. We also tried to further clarify the association between numerical magnitude processing and complex calculation by also including relevant arithmetical subskills, i.e. arithmetic facts, needed for complex calculation that are also known to be dependent on numerical magnitude processing. Results showed that the associations between symbolic numerical magnitude processing and mental and algorithmic computation were fully explained by individual differences in elementary arithmetic fact knowledge.
5. It Works Both Ways: Transfer Difficulties between Manipulatives and Written Subtraction Solutions
David H. Uttal
2013-01-01
Full Text Available Three experiments compared performance and transfer among children aged 83–94 months after written or manipulatives instruction on two-digit subtraction. In Experiment 1a, children learned with manipulatives or with traditional written numerals. All children then completed a written posttest. Experiment 1b investigated whether salient or perceptually attractive manipulatives affected transfer. Experiment 2 investigated whether instruction with writing would transfer to a manipulatives-based posttest. Children demonstrated performance gains when the posttest format was identical to the instructed format but failed to demonstrate transfer from the instructed format to an incongruent posttest. The results indicate that the problem in transferring from manipulatives instruction to written assessments stems from a general difficulty in using knowledge gained in one format (e.g., manipulatives in another format (e.g., writing. Taken together, the results have important implications for research and teaching in early mathematics. Teachers should consider making specific links and alignments between written and manipulatives-based representations of the same problems.
6. A posterior registration and subtraction of periapical radiographs for the evaluation of external apical root resorption after orthodontic treatment
Kreich, Eliane Maria; Chibinski, Ana Claudia; Coelho, Ulisses; Wambier, Leticia Stadler; Zedebski, Rosaio De Arruda Moura [School of Dentistry, Ponta Grossa State University, Ponta Grossa, Parana (Brazil); De Moraes, Mari Eli Leonelli; De Moraes, Luiz Cesar [Dept. of Dental Radiology, School of Dentistry, State University of Sao Paulo, Sao Jose dos Campos, Sao Paulo (Brazil)
2016-03-15
This study employed a posteriori registration and subtraction of radiographic images to quantify the apical root resorption in maxillary permanent central incisors after orthodontic treatment, and assessed whether the external apical root resorption (EARR) was related to a range of parameters involved in the treatment. A sample of 79 patients (mean age, 13.5±2.2 years) with no history of trauma or endodontic treatment of the maxillary permanent central incisors was selected. Periapical radiographs taken before and after orthodontic treatment were digitized and imported to the Regeemy software. Based on an analysis of the posttreatment radiographs, the length of the incisors was measured using Image J software. The mean EARR was described in pixels and relative root resorption (%). The patient's age and gender, tooth extraction, use of elastics, and treatment duration were evaluated to identify possible correlations with EARR. The mean EARR observed was 15.44±12.1 pixels (5.1% resorption). No differences in the mean EARR were observed according to patient characteristics (gender, age) or treatment parameters (use of elastics, treatment duration). The only parameter that influenced the mean EARR of a patient was the need for tooth extraction. A posteriori registration and subtraction of periapical radiographs was a suitable method to quantify EARR after orthodontic treatment, and the need for tooth extraction increased the extent of root resorption after orthodontic treatment.
7. A posteriori registration and subtraction of periapical radiographs for the evaluation of external apical root resorption after orthodontic treatment
Chibinski, Ana Cláudia; Coelho, Ulisses; Wambier, Letícia Stadler; Zedebski, Rosário de Arruda Moura; de Moraes, Mari Eli Leonelli; de Moraes, Luiz Cesar
2016-01-01
Purpose This study employed a posteriori registration and subtraction of radiographic images to quantify the apical root resorption in maxillary permanent central incisors after orthodontic treatment, and assessed whether the external apical root resorption (EARR) was related to a range of parameters involved in the treatment. Materials and Methods A sample of 79 patients (mean age, 13.5±2.2 years) with no history of trauma or endodontic treatment of the maxillary permanent central incisors was selected. Periapical radiographs taken before and after orthodontic treatment were digitized and imported to the Regeemy software. Based on an analysis of the posttreatment radiographs, the length of the incisors was measured using Image J software. The mean EARR was described in pixels and relative root resorption (%). The patient's age and gender, tooth extraction, use of elastics, and treatment duration were evaluated to identify possible correlations with EARR. Results The mean EARR observed was 15.44±12.1 pixels (5.1% resorption). No differences in the mean EARR were observed according to patient characteristics (gender, age) or treatment parameters (use of elastics, treatment duration). The only parameter that influenced the mean EARR of a patient was the need for tooth extraction. Conclusion A posteriori registration and subtraction of periapical radiographs was a suitable method to quantify EARR after orthodontic treatment, and the need for tooth extraction increased the extent of root resorption after orthodontic treatment. PMID:27051635
8. Cadmium Subtraction Method for the Active Albedo Neutron Interrogation of Uranium
Worrall, Louise G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Croft, Stephen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
2015-02-01
This report describes work performed under the Next Generation Safeguards Initiative (NGSI) Cadmium Subtraction Project. The project objective was to explore the difference between the traditional cadmium (Cd) ratio signature and a proposed alternative Cd subtraction (or Cd difference) approach. The thinking behind the project was that a Cd subtraction method would provide a more direct measure of multiplication than the existing Cd ratio method. At the same time, it would be relatively insensitive to changes in neutron detection efficiency when properly calibrated. This is the first published experimental comparison and evaluation of the Cd ratio and Cd subtraction methods.
9. On-sky tests of sky-subtraction methods for fiber-fed spectrographs
Rodrigues, Myriam; Hammer, Francois; Royer, Frederic; Evans, C J; Puech, Mathieu; Flores, Hector; Guinouard, Isabelle; Causi, Gianluca Li; Disseau, Karen; Yang, Yanbin
2016-01-01
We present preliminary results on on-sky test of sky subtraction methods for fiber-fed spectrograph. Using dedicated observation with FLAMES/VLT in I-band, we have tested the accuracy of the sky subtraction for 4 sky subtraction methods: mean sky, closest sky, dual stare and cross-beam switching. The cross beam-switching and dual stare method reach accuracy and precision of the sky subtraction under 1%. In contrast to the commonly held view in the literature, this result points out that fiber-fed spectrographs are adapted for the observations of faint targets.
10. Suppression Subtractive Hybridization (SSH) and its modifications in microbiological research.
Huang, Xiaowei; Li, Yunxia; Niu, Qiuhong; Zhang, Keqin
2007-09-01
Suppression subtractive hybridization (SSH) is an effective approach to identify the genes that vary in expression levels during different biological processes. It is often used in higher eukaryotes to study the molecular regulation in complex pathogenic progress, such as tumorigenesis and other chronic multigene-associated diseases. Because microbes have relatively smaller genomes compared with eukaryotes, aside from the analysis at the mRNA level, SSH as well as its modifications have been further employed to isolate specific chromosomal locus, study genomic diversity related with exceptional bacterial secondary metabolisms or genes with special microbial function. This review introduces the SSH and its associated methods and focus on their applications to detect specific functional genes or DNA markers in microorganisms.
Razzak, M.A.; Botti, R.E.; Macintyre, W.J.
1976-05-01
A method is presented for the simple, non-computerized analysis of the radiohippuran renogram by subtraction of the extrarenal radioactivity as monitored simultaneously by a detector centered over the manubrium sterni. This method requires the application of a calibration factor, relating the level of radioactivity recorded by the sternal detector to that over each kidney area at the end point of the phase of initial rise on each side separately. The results in 15 normal individuals showed a narrow range of values, indicating a high degree of resolution. Verification of the basis of this method of analysis was obtained by accounting for all of the counting rate as extrarenal sources in the tracings of nephrectomized subjects. A further advantage is that the tracing recorded by the sternal detector may be used to calculate renal blood flow.
12. Background Subtraction with DirichletProcess Mixture Models.
Haines, Tom S F; Tao Xiang
2014-04-01
Video analysis often begins with background subtraction. This problem is often approached in two steps-a background model followed by a regularisation scheme. A model of the background allows it to be distinguished on a per-pixel basis from the foreground, whilst the regularisation combines information from adjacent pixels. We present a new method based on Dirichlet process Gaussian mixture models, which are used to estimate per-pixel background distributions. It is followed by probabilistic regularisation. Using a non-parametric Bayesian method allows per-pixel mode counts to be automatically inferred, avoiding over-/under- fitting. We also develop novel model learning algorithms for continuous update of the model in a principled fashion as the scene changes. These key advantages enable us to outperform the state-of-the-art alternatives on four benchmarks.
13. Hierarchical CodeBook for background subtraction in MRF
Shao, Quan; Tang, Zhixing; Han, Songchen
2013-11-01
Foreground detection is the key low-level fundamental work in intelligent video surveillance. This paper proposed a hierarchical background subtraction algorithm consisted of block-based stage and pixel-based stage for it. In block-based stage, obvious backgrounds got detected via block-based CodeBook, leaving spatial relations among suspicious foreground pixels undestroyed. Pixel-based stage further eliminated the left background pixels with the introduction of spatial and temporal relations in a MRF-MAP framework. Then comparative experiments were conducted to evaluate the performance of the scheme in three dimensions - detection accuracy, update speed and memory consumption. Proposed approach possesses the highest detection precision and consumes the second least memories. And the update speed is of real-time level.
14. Subtraction of "accidentals" and the validity of Bell tests
Thompson, C H
1999-01-01
In some key Bell experiments, including two of the well-known ones by Alain Aspect, 1981-2, it is only after the subtraction of accidentals'' from the coincidence counts that we get violations of Bell tests. The data adjustment, producing increases of up to 60% in the test statistics, has never been adequately justified. Few published experiments give sufficient information for the reader to make a fair assessment. There is a straightforward and well known realist model that fits the unadjusted data very well. In this paper, the logic of this realist model and the reasoning used by experimenters in justification of the data adjustment are discussed. It is concluded that the evidence from all Bell experiments is in urgent need of re-assessment, in the light of all the known loopholes''. Invalid Bell tests have frequently been used, neglecting an improved one derived by Clauser and Horne in 1974. Local causal'' explanations for the observations have been wrongfully neglected.
15. PSF subtraction to search for distant Jupiters with SPITZER
Rameau, Julien; Artigau, Etienne; Baron, Frédérique; Lafrenière, David; Doyon, Rene; Malo, Lison; Naud, Marie-Eve; Delorme, Philippe; Janson, Markus; Albert, Loic; Gagné, Jonathan; Beichman, Charles
2015-12-01
In the course of the search for extrasolar planets, a focus has been made towards rocky planets very close (within few AUs) to their parent stars. However, planetary systems might host gas giants as well, possibly at larger separation from the central star. Direct imaging is the only technique able to probe the outer part of planetary systems. With the advent of the new generation of planet finders like GPI and SPHERE, extrasolar systems are now studied at the solar system scale. Nevertheless, very extended planetary systems do exist and have been found (Gu Ps, AB Pic b, etc.). They are easier to detect and characterize. They are also excellent proxy for close-in gas giants that are detected from the ground. These planets have no equivalent in our solar system and their origin remain a matter of speculation. In this sense, studying planetary systems from its innermost to its outermost part is therefore mandatory to have a clear understanding of its architecture, hence hints of its formation and evolution. We are carrying out a space-based survey using SPITZER to search for distant companions around a well-characterized sample of 120 young and nearby stars. We designed an observing strategy that allows building a very homogeneous PSF library. With this library, we perform a PSF subtraction to search for planets from 10’’ down to 1’’. In this poster, I will present the library, the different algorithms used to subtract the PSF, and the promising detection sensitivity that we are able to reach with this survey. This project to search for the most extreme planetary systems is unique in the exoplanet community. It is also the only realistic mean of directly imaging and subsequently obtaining spectroscopy of young Saturn or Jupiter mass planets in the JWST-era.
16. Digital Culture and Digital Library
Yalçın Yalçınkaya
2016-12-01
Full Text Available In this study; digital culture and digital library which have a vital connection with each other are examined together. The content of the research consists of the interaction of culture, information, digital culture, intellectual technologies, and digital library concepts. The study is an entry work to integrity of digital culture and digital library theories and aims to expand the symmetry. The purpose of the study is to emphasize the relation between the digital culture and digital library theories acting intersection of the subjects that are examined. Also the perspective of the study is based on examining the literature and analytical evaluation in both studies (digital culture and digital library. Within this context, the methodology of the study is essentially descriptive and has an attribute for the transmission and synthesis of distributed findings produced in the field of the research. According to the findings of the study results, digital culture is an inclusive term that describes the effects of intellectual technologies in the field of information and communication. Information becomes energy and the spectrum of the information is expanding in the vertical rise through the digital culture. In this context, the digital library appears as a new living space of a new environment. In essence, the digital library is information-oriented; has intellectual technology support and digital platform; is in a digital format; combines information resources and tools in relationship/communication/cooperation by connectedness, and also it is the dynamic face of the digital culture in time and space independence. Resolved with the study is that the digital libraries are active and effective in the formation of global knowing and/or mass wisdom in the process of digital culture.
17. The AAPM/RSNA physics tutorial for residents: digital fluoroscopy.
Pooley, R A; McKinney, J M; Miller, D A
2001-01-01
A digital fluoroscopy system is most commonly configured as a conventional fluoroscopy system (tube, table, image intensifier, video system) in which the analog video signal is converted to and stored as digital data. Other methods of acquiring the digital data (eg, digital or charge-coupled device video and flat-panel detectors) will become more prevalent in the future. Fundamental concepts related to digital imaging in general include binary numbers, pixels, and gray levels. Digital image data allow the convenient use of several image processing techniques including last image hold, gray-scale processing, temporal frame averaging, and edge enhancement. Real-time subtraction of digital fluoroscopic images after injection of contrast material has led to widespread use of digital subtraction angiography (DSA). Additional image processing techniques used with DSA include road mapping, image fade, mask pixel shift, frame summation, and vessel size measurement. Peripheral angiography performed with an automatic moving table allows imaging of the peripheral vasculature with a single contrast material injection.
18. A subtraction scheme for computing QCD jet cross sections at NNLO. Integrating the iterated singly-unresolved subtraction terms
Bolzoni, Paolo [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik; Somogyi, Gabor [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Trocsanyi, Zoltan [Debrecen Univ. (Hungary); Hungarian Academy of Sciences, Debrecen (Hungary). Inst. of Nuclear Research
2010-11-15
We perform the integration of all iterated singly-unresolved subtraction terms over the two-particle factorized phase space. We also sum over the unresolved parton flavours. The final result can be written as a convolution (in colour space) of the Born cross section and an insertion operator. We spell out the insertion operator in terms of 24 basic integrals that are defined explicitly. We compute the coefficients of the Laurent-expansion of these integrals in two different ways, with the method of Mellin-Barnes representations and sector decomposition. Finally, we present the Laurentexpansion of the full insertion operator for the specific examples of electron-positron annihilation into two and three jets. (orig.)
19. Digital photography
Windsor, J S; Rodway, G W; Middleton, P M; McCarthy, S
2006-01-01
The emergence of a new generation of "point-and-shoot" digital cameras offers doctors a compact, portable and user-friendly solution to the recording of highly detailed digital photographs and video images...
20. Putting Essential Understanding of Addition and Subtraction into Practice: Pre-K-2
Caldwell, Janet H.; Kobett, Beth; Karp, Karen
2014-01-01
Do your students have the incorrect idea that addition "makes numbers bigger" and subtraction "makes numbers smaller"? Do they believe that subtraction is always "taking away"? What tasks can you offer--what questions can you ask--to determine what your students know or don't know--and move them forward in their…
1. Putting Essential Understanding of Addition and Subtraction into Practice: Pre-K-2
Caldwell, Janet H.; Kobett, Beth; Karp, Karen
2014-01-01
Do your students have the incorrect idea that addition "makes numbers bigger" and subtraction "makes numbers smaller"? Do they believe that subtraction is always "taking away"? What tasks can you offer--what questions can you ask--to determine what your students know or don't know--and move them forward in their…
2. Curricular Approaches to Connecting Subtraction to Addition and Fostering Fluency with Basic Differences in Grade 1
Baroody, Arthur J.
2016-01-01
Six widely used US Grade 1 curricula do not adequately address the following three developmental prerequisites identified by a proposed learning trajectory for the meaningful learning of the subtraction-as-addition strategy (e.g., for 13-8 think "what + 8 = 13?"): (a) reverse operations (adding 8 is undone by subtracting 8); (b) common…
3. Digital Tectonics
Christiansen, Karl; Borup, Ruben; Søndergaard, Asbjørn;
2014-01-01
Digital Tectonics treats the architectonical possibilities in digital generation of form and production. The publication is the first volume of a series, in which aspects of the strategic focus areas of the Aarhus School of Architecture will be disseminated.......Digital Tectonics treats the architectonical possibilities in digital generation of form and production. The publication is the first volume of a series, in which aspects of the strategic focus areas of the Aarhus School of Architecture will be disseminated....
4. Digital squares
Forchhammer, Søren; Kim, Chul E
1988-01-01
Digital squares are defined and their geometric properties characterized. A linear time algorithm is presented that considers a convex digital region and determines whether or not it is a digital square. The algorithm also determines the range of the values of the parameter set of its preimages....... The analysis involves transforming the boundary of a digital region into parameter space of slope and y-intercept...
5. Digital Citizenship
Isman, Aytekin; Canan Gungoren, Ozlem
2014-01-01
Era in which we live is known and referred as digital age.In this age technology is rapidly changed and developed. In light of these technological advances in 21st century, schools have the responsibility of training "digital citizen" as well as a good citizen. Digital citizens must have extensive skills, knowledge, Internet and …
6. Speech Enhancement with Geometric Advent of Spectral Subtraction using Connected Time-Frequency Regions Noise Estimation
Nasir Saleem
2013-06-01
Full Text Available Speech enhancement with Geometric Advent of Spectral subtraction using connected time-frequency regions noise estimation aims to de-noise or reduce background noise from the noisy speech for better quality, pleasantness and improved intelligibility. Numerous enhancement methods are proposed including spectral subtraction, subspace, statistical with different noise estimations. The traditional spectral subtraction techniques are reasonably simple to implement and suffer from musical noise. This study addresses the new approach for speech enhancement which has minimized the insufficiencies in traditional spectral subtraction algorithms using MCRA. This approach with noise estimation has been evolved with PESQ, the ITU-T standard; Frequency weighted segmental SNR and weighted spectral slope. The analysis shows that Geometric approach with time-frequency connected regions has improved results than old-fashioned spectral subtraction algorithms. The normal hearing tests has suggested that new approach has lower audible musical noise.
7. Improvement of two-way continuous-variable quantum key distribution with virtual photon subtraction
Zhao, Yijia; Zhang, Yichen; Li, Zhengyu; Yu, Song; Guo, Hong
2017-08-01
We propose a method to improve the performance of two-way continuous-variable quantum key distribution protocol by virtual photon subtraction. The virtual photon subtraction implemented via non-Gaussian post-selection not only enhances the entanglement of two-mode squeezed vacuum state but also has advantages in simplifying physical operation and promoting efficiency. In two-way protocol, virtual photon subtraction could be applied on two sources independently. Numerical simulations show that the optimal performance of renovated two-way protocol is obtained with photon subtraction only used by Alice. The transmission distance and tolerable excess noise are improved by using the virtual photon subtraction with appropriate parameters. Moreover, the tolerable excess noise maintains a high value with the increase in distance so that the robustness of two-way continuous-variable quantum key distribution system is significantly improved, especially at long transmission distance.
8. Digital preservation
Deegan, Marilyn
2013-01-01
Digital preservation is an issue of huge importance to the library and information profession right now. With the widescale adoption of the internet and the rise of the world wide web, the world has been overwhelmed by digital information. Digital data is being produced on a massive scale by individuals and institutions: some of it is born, lives and dies only in digital form, and it is the potential death of this data, with its impact on the preservation of culture, that is the concern of this book. So how can information professionals try to remedy this? Digital preservation is a complex iss
9. Digital Natives or Digital Tribes?
Watson, Ian Robert
2013-01-01
This research builds upon the discourse surrounding digital natives. A literature review into the digital native phenomena was undertaken and found that researchers are beginning to identify the digital native as not one cohesive group but of individuals influenced by other factors. Primary research by means of questionnaire survey of technologies…
10. Dual energy subtraction method for breast calcification imaging
Koukou, Vaia; Martini, Niki; Fountos, George; Michail, Christos; Sotiropoulou, Panagiota; Bakas, Athanasios; Kalyvas, Nektarios; Kandarakis, Ioannis; Speller, Robert; Nikiforidis, George
2017-03-01
The aim of this work was to present an experimental dual energy (DE) method for the visualization of microcalcifications (μCs). A modified radiographic X-ray tube combined with a high resolution complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) X-ray detector was used. A 40/70 kV spectral combination was filtered with 100 μm cadmium (Cd) and 1000 μm copper (Cu) for the low/high-energy combination. Homogenous and inhomogeneous breast phantoms and two calcification phantoms were constructed with various calcification thicknesses, ranging from 16 to 152 μm . Contrast-to-noise ratio (CNR) was calculated from the DE subtracted images for various entrance surface doses. A calcification thickness of 152 μm was visible, with mean glandular doses (MGD) in the acceptable levels (below 3 mGy). Additional post-processing on the DE images of the inhomogeneous breast phantom resulted in a minimum visible calcification thickness of 93 μm (MGD=1.62 mGy). The proposed DE method could potentially improve calcification visibility in DE breast calcification imaging.
11. Skycorr: A general tool for spectroscopic sky subtraction
Noll, S; Kimeswenger, S; Barden, M; Jones, A M; Modigliani, A; Szyszka, C; Taylor, J
2014-01-01
Airglow emission lines, which dominate the optical-to-near-IR sky radiation, show strong, line-dependent variability on various time scales. Therefore, the subtraction of the sky background in the affected wavelength regime becomes a problem if plain sky spectra have to be taken at a different time as the astronomical data. A solution of this issue is the physically motivated scaling of the airglow lines in the plain sky data to fit the sky lines in the object spectrum. We have developed a corresponding instrument-independent approach based on one-dimensional spectra. Our code skycorr separates sky lines and sky/object continuum by an iterative approach involving a line finder and airglow line data. The sky lines are grouped according to their expected variability. The line groups in the sky data are then scaled to fit the sky in the science data. Required pixel-specific weights for overlapping groups are taken from a comprehensive airglow model. Deviations in the wavelength calibration are corrected by fitti...
12. Microwave detection of breast tumors: comparison of skin subtraction algorithms
Fear, Elise C.; Stuchly, Maria A.
2000-07-01
Early detection of breast cancer is an important part of effective treatment. Microwave detection of breast cancer is of interest due to the contrast in dielectric properties of normal and malignant breast tissues. We are investigating a confocal microwave imaging system that adapts ideas from ground penetrating radar to breast cancer detection. In the proposed system, the patient lies prone with the breast extending through a hole in the examining table and encircled by an array of antennas. The breast is illuminated sequentially by each antenna with an ultrawideband signal, and the returns are recorded at the same antenna. Because the antennas are offset from the breast, the dominant component of the recorded returns is the reflection from the thin layer of breast skin. Two methods of reducing this reflection are compared, namely approximation of the signal with two time shifted, scaled and summed returns from a cylinder of skin, and subtraction of the mean of the set of aligned returns. Both approaches provide effective decrease of the skin signal, allowing for tumor detection.
13. Subtractive fuzzy classifier based driver distraction levels classification using EEG.
2013-09-01
[Purpose] In earlier studies of driver distraction, researchers classified distraction into two levels (not distracted, and distracted). This study classified four levels of distraction (neutral, low, medium, high). [Subjects and Methods] Fifty Asian subjects (n=50, 43 males, 7 females), age range 20-35 years, who were free from any disease, participated in this study. Wireless EEG signals were recorded by 14 electrodes during four types of distraction stimuli (Global Position Systems (GPS), music player, short message service (SMS), and mental tasks). We derived the amplitude spectrum of three different frequency bands, theta, alpha, and beta of EEG. Then, based on fusion of discrete wavelet packet transforms and fast fourier transform yield, we extracted two features (power spectral density, spectral centroid frequency) of different wavelets (db4, db8, sym8, and coif5). Mean ± SD was calculated and analysis of variance (ANOVA) was performed. A fuzzy inference system classifier was applied to different wavelets using the two extracted features. [Results] The results indicate that the two features of sym8 posses highly significant discrimination across the four levels of distraction, and the best average accuracy achieved by the subtractive fuzzy classifier was 79.21% using the power spectral density feature extracted using the sym8 wavelet. [Conclusion] These findings suggest that EEG signals can be used to monitor distraction level intensity in order to alert drivers to high levels of distraction.
14. Data series subtraction with unknown and unmodeled background noise
Vitale, Stefano; Dolesi, Rita; Ferroni, Valerio; Hueller, Mauro; Vetrugno, Daniele; Weber, William Joseph; Audley, Heather; Danzmann, Karsten; Diepholz, Ingo; Hewitson, Martin; Korsakova, Natalia; Ferraioli, Luigi; Gibert, Ferran; Karnesis, Nikolaos; Nofrarias, Miquel; Inchauspe, Henri; Plagnol, Eric; Jennrich, Oliver; McNamara, Paul W; Armano, Michele; Thorpe, James Ira; Wass, Peter
2014-01-01
LISA Pathfinder (LPF), ESA's precursor mission to a gravitational wave observatory, will measure the degree to which two test-masses can be put into free-fall, aiming to demonstrate a residual relative acceleration with a power spectral density (PSD) below 30 fm/s$^2$/Hz$^{1/2}$ around 1 mHz. In LPF data analysis, the measured relative acceleration data series must be fit to other various measured time series data. This fitting is required in different experiments, from system identification of the test mass and satellite dynamics to the subtraction of noise contributions from measured known disturbances. In all cases, the background noise, described by the PSD of the fit residuals, is expected to be coloured, requiring that we perform such fits in the frequency domain. This PSD is unknown {\\it a priori}, and a high accuracy estimate of this residual acceleration noise is an essential output of our analysis. In this paper we present a fitting method based on Bayesian parameter estimation with an unknown frequ...
15. Generalized Subtraction Schemes for the Difference Formulation in Radiation Transport
Luu, T; Brooks, E; Szoke, A
2008-07-25
In the difference formulation for the transport of thermally emitted photons, the photon intensity is defined relative to a reference field, the black body at the local material temperature. This choice of reference field removes the cancellation between thermal emission and absorption that is responsible for noise in the Monte Carlo solution of thick systems, but introduces time and space derivative source terms that can not be determined until the end of the time step. It can also lead to noise induced crashes under certain conditions where the real physical photon intensity differs strongly from a black body at the local material temperature. In this report, we consider a difference formulation relative to the material temperature at the beginning of the time step, and in the situations where the radiation intensity more closely follows a temperature other than the local material temperature, that temperature. The result is a method where iterative solution of the material energy equation is efficient and noise induced crashes are avoided. To support our contention that the resulting generalized subtraction scheme is robust, and therefore suitable for practical use, we perform a stability analysis in the thick limit where instabilities usually occur.
16. Suppression subtractive hybridization: a method for generating differentially regulated or tissue-specific cDNA probes and libraries.
1996-01-01
A new and highly effective method, termed suppression subtractive hybridization (SSH), has been developed for the generation of subtracted cDNA libraries. It is based primarily on a recently described technique called suppression PCR and combines normalization and subtraction in a single procedure. The normalization step equalizes the abundance of cDNAs within the target population and the subtraction step excludes the common sequences between the target and driver populations. In a model sys...
17. Normal angiogram after myocardial infarction in young patients: a prospective clinical-angiographic and long-term follow-up study.
Fournier, J A; Sánchez-González, A; Quero, J; Cortacero, J A; Cabello, A; Revello, A; Romero, R
1997-08-08
This is an observational study in which we compared the clinical characteristics and the long-term course of young patients having acute myocardial infarction and angiographically normal coronary arteries and young patients showing significant coronary artery disease. In 87 patients aged 1 risk factor, P or = 2 packs per day, P < 0.05), had less frequent hypertension (0 vs. 25%, P < 0.05), hypercholesterolemia (17% vs. 52%, P = 0.02) and had a lower mean total cholesterol level (201 +/- 42 vs. 245 +/- 60 mg/100 ml, P < 0.05) than patients in Group 2. They also had a more common onset of their infarction during heavy physical exertion (67% vs. 17%, P < 0.001). A history of previous myocardial infarction, infarct location, global left ventricular function and regional wall motion were similar in both groups. After a mean follow-up period of 41 +/- 23 months, no patient died or had a second myocardial infarction in Group 1, and 4 patients had died in Group 2. The appearance of angina, less frequent in Group 1 than Group 2, tended to correlate with the extension of the coronary artery disease. We concluded that young patients with myocardial infarction have good prognosis irrespective of the coronary anatomy, although patients with normal coronary angiograms had less risk factors and less frequent new ischaemic events.
18. Comparison of operator radiation exposure with optimized radiation protection devices during coronary angiograms and ad hoc percutaneous coronary interventions by radial and femoral routes.
Brasselet, Camille; Blanpain, Thierry; Tassan-Mangina, Sophie; Deschildre, Alain; Duval, Sébastien; Vitry, Fabien; Gaillot-Petit, Nathalie; Clément, Jean Paul; Metz, Damien
2008-01-01
19. A Wireless FSCV Monitoring IC with Analog Background Subtraction and UWB Telemetry
Dorta-Quiñones, Carlos I.; Wang, Xiao Y.; Dokania, Rajeev K.; Gailey, Alycia; Lindau, Manfred; Apsel, Alyssa B.
2015-01-01
A 30-μW wireless fast-scan cyclic voltammetry monitoring integrated circuit for ultra-wideband (UWB) transmission of dopamine release events in freely-behaving small animals is presented. On-chip integration of analog background subtraction and UWB telemetry yields a 32-fold increase in resolution versus standard Nyquist-rate conversion alone, near a four-fold decrease in the volume of uplink data versus single-bit, third-order, delta-sigma modulation, and more than a 20-fold reduction in transmit power versus narrowband transmission for low data rates. The 1.5-mm2 chip, which was fabricated in 65-nm CMOS technology, consists of a low-noise potentiostat frontend, a two-step analog-to-digital converter (ADC), and an impulse-radio UWB transmitter (TX). The duty-cycled frontend and ADC/UWB-TX blocks draw 4 μA and 15 μA from 3-V and 1.2-V supplies, respectively. The chip achieves an input-referred current noise of 92 pArms and an input current range of ±430 nA at a conversion rate of 10 kHz. The packaged device operates from a 3-V coin-cell battery, measures 4.7 × 1.9 cm2, weighs 4.3 g (including the battery and antenna), and can be carried by small animals. The system was validated by wirelessly recording flow-injection of dopamine with concentrations in the range of 250 nM to 1 μM with a carbon-fiber microelectrode (CFM) using 300-V/s FSCV. PMID:26057983
20. A Wireless FSCV Monitoring IC With Analog Background Subtraction and UWB Telemetry.
Dorta-Quiñones, Carlos I; Wang, Xiao Y; Dokania, Rajeev K; Gailey, Alycia; Lindau, Manfred; Apsel, Alyssa B
2016-04-01
A 30-μW wireless fast-scan cyclic voltammetry monitoring integrated circuit for ultra-wideband (UWB) transmission of dopamine release events in freely-behaving small animals is presented. On-chip integration of analog background subtraction and UWB telemetry yields a 32-fold increase in resolution versus standard Nyquist-rate conversion alone, near a four-fold decrease in the volume of uplink data versus single-bit, third-order, delta-sigma modulation, and more than a 20-fold reduction in transmit power versus narrowband transmission for low data rates. The 1.5- mm(2) chip, which was fabricated in 65-nm CMOS technology, consists of a low-noise potentiostat frontend, a two-step analog-to-digital converter (ADC), and an impulse-radio UWB transmitter (TX). The duty-cycled frontend and ADC/UWB-TX blocks draw 4 μA and 15 μA from 3-V and 1.2-V supplies, respectively. The chip achieves an input-referred current noise of 92 pA(rms) and an input current range of ±430 nA at a conversion rate of 10 kHz. The packaged device operates from a 3-V coin-cell battery, measures 4.7 × 1.9 cm(2), weighs 4.3 g (including the battery and antenna), and can be carried by small animals. The system was validated by wirelessly recording flow-injection of dopamine with concentrations in the range of 250 nM to 1 μM with a carbon-fiber microelectrode (CFM) using 300-V/s FSCV.
1. Redefining the Whole: Common Errors in Elementary Preservice Teachers' Self-Authored Word Problems for Fraction Subtraction
Dixon, Juli K.; Andreasen, Janet B.; Avila, Cheryl L.; Bawatneh, Zyad; Deichert, Deana L.; Howse, Tashana D.; Turner, Mercedes Sotillo
2014-01-01
A goal of this study was to examine elementary preservice teachers' (PSTs) ability to contextualize and decontextualize fraction subtraction by asking them to write word problems to represent fraction subtraction expressions and to choose prewritten word problems to support given fraction subtraction expressions. Three themes emerged from the…
2. Exponential Renormalization II: Bogoliubov's R-operation and momentum subtraction schemes
Ebrahimi-Fard, Kurusch
2011-01-01
We develop further the recently introduced exponential method for renormalisation in perturbative quantum field theory. It turns out that exponential renormalisation provides a meaningful recursive method in the context of renormalisation using momentum subtraction schemes. We explore in detail its link to Bogoliubov's R-operation. Our results shed new light on classical ideas, such as the role of oversubtractions in the BPHZ method. They also suggest that the ambiguities of the renormalisation process carry, besides a physical structure (encoded, e.g. in the RG equations and the choice of subtraction points in momentum subtraction schemes), an interesting, though purely algebraic structure.
3. Exponential renormalisation. II. Bogoliubov's R-operation and momentum subtraction schemes
Ebrahimi-Fard, Kurusch [Instituto de Ciencias Matematicas, C/ Nicolas Cabrera, no. 13-15, 28049 Madrid (Spain); Patras, Frederic [Laboratoire J.-A. Dieudonne UMR 6621, CNRS, Parc Valrose, 06108 Nice Cedex 02 (France)
2012-08-15
This article aims at advancing the recently introduced exponential method for renormalisation in perturbative quantum field theory. It is shown that this new procedure provides a meaningful recursive scheme in the context of the algebraic and group theoretical approach to renormalisation. In particular, we describe in detail a Hopf algebraic formulation of Bogoliubov's classical R-operation and counterterm recursion in the context of momentum subtraction schemes. This approach allows us to propose an algebraic classification of different subtraction schemes. Our results shed light on the peculiar algebraic role played by the degrees of Taylor jet expansions, especially the notion of minimal subtraction and oversubtractions.
4. Digital Insights
Knudsen, Gry Høngsmark
, by incorporating media as both channel, frame, and apparatus for advertising response, the dissertation brings into attention that more aspects than the text-reader relationship influence ad response. Finally, the dissertation proposes the assemblage approach for exploring big data in consumer culture research......This dissertation forwards the theory of digital consumer-response as a perspective to examine how digital media practices influence consumers’ response to advertising. Digital consumer-response is a development of advertising theory that encompasses how consumers employ their knowledge...... and practices with digital media, when they meet and interpret advertising. Through studies of advertising response on YouTube and experiments with consumers’ response to digitally manipulated images, the dissertation shows how digital media practices facilitate polysemic and socially embedded advertising...
5. WAXS fat subtraction model to estimate differential linear scattering coefficients of fatless breast tissue: Phantom materials evaluation
Tang, Robert Y., E-mail: [email protected] [Biomolecular Sciences Program, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario P3E 2C6 (Canada); Laamanen, Curtis, E-mail: [email protected]; McDonald, Nancy, E-mail: [email protected] [Department of Physics, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario P3E 2C6 (Canada); LeClair, Robert J., E-mail: [email protected] [Department of Physics, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario P3E 2C6, Canada and Biomolecular Sciences Program, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario P3E 2C6 (Canada)
2014-05-15
measure μ{sub s} of homogeneous samples was quantitatively accurate. Simple WAXS models predicted the probabilities for specific x-ray scattering to occur from heterogeneous biopsies. The fat subtraction model can allow μ{sub s} signals of breast cancer and fibroglandular tissue to be compared without the effects of fat provided there is an independent measurement of the fat volume fraction ν{sub f}. Future work will consist of devising a quantitative x-ray digital imaging method to estimate ν{sub f} in ex vivo breast samples.
6. Digital Forensics
Ψευτέλης, Αθανάσιος Δημήτρης
2013-01-01
A reprint from American Scientist the magazine of Sigma Xi, The Scientific Research Society Since the 1980s, computers have had increasing roles in all aspects of human life—including an involvement in criminal acts. This development has led to the rise of digital forensics, the uncovering and examination of evidence located on all things electronic with digital storage, including computers, cell phones, and networks. Digital forensics researchers and practitione...
7. Digital printing
Sobotka, Werner K.
1997-02-01
Digital printing is described as a tool to replace conventional printing machines completely. Still this goal was not reached until now with any of the digital printing technologies to be described in the paper. Productivity and costs are still the main parameters and are not really solved until now. Quality in digital printing is no problem anymore. Definition of digital printing is to transfer digital datas directly on the paper surface. This step can be carried out directly or with the use of an intermediate image carrier. Keywords in digital printing are: computer- to-press; erasable image carrier; image carrier with memory. Digital printing is also the logical development of the new digital area as it is pointed out in Nicholas Negropotes book 'Being Digital' and also the answer to networking and Internet technologies. Creating images text and color in one country and publishing the datas in another country or continent is the main advantage. Printing on demand another big advantage and last but not least personalization the last big advantage. Costs and being able to coop with this new world of prepress technology is the biggest disadvantage. Therefore the very optimistic growth rates for the next few years are really nonexistent. The development of complete new markets is too slow and the replacing of old markets is too small.
8. Digital displacements
Pors, Anja Svejgaard
2014-01-01
In recent years digital reforms are being introduced in the municipal landscape of Denmark. The reforms address the interaction between citizen and local authority. The aim is, that by 2015 at least 80 per cent of all correspondence between citizens and public authority will be transmitted through...... digital interface. However, the transformation of citizen services from traditional face-to-face interaction to digital self-service gives rise to new practices; some citizens need support to be able to manage self-service through digital tools. A mixture of support and teaching, named co...
9. Contrast-enhanced digital mammography
Dromain, Clarisse [Department of Radiology, Institut Gustave-Roussy, 39, rue Camille Desmoulins, 94805 Villejuif Cedex (France)], E-mail: [email protected]; Balleyguier, Corinne; Adler, Ghazal [Department of Radiology, Institut Gustave-Roussy, 39, rue Camille Desmoulins, 94805 Villejuif Cedex (France); Garbay, Jean Remi [Department of Surgery, Institut Gustave-Roussy, 39, rue Camille Desmoulins, 94805 Villejuif Cedex (France); Delaloge, Suzette [Department of Medicine, Institut Gustave-Roussy, 39, rue Camille Desmoulins, 94805 Villejuif Cedex (France)
2009-01-15
CEDM is a recent development of digital mammography using the intra-venous injection of an iodinated contrast agent in conjunction with a mammography examination. Two techniques have been developed to perform CEDM examinations: the temporal subtraction technique with acquisition of high-energy images before and after contrast medium injection and the dual energy technique with acquisition of a pair of low and high-energy images only after contrast medium injection. The temporal subtraction technique offered the possibility to analyze the kinetic curve of enhancement of breast lesions, similarly to breast MRI. The dual energy technique do not provide information about the kinetic of tumor enhancement but allows the acquisition of multiples views of the same breast or bilateral examination and is less sensitive to patient motion than temporal CEDM. Initial clinical experience has shown the ability of CEDM to map the distribution of neovasculature induced by cancer using mammography. Moreover, previous studies have shown a superiority of MX + CEDM, either for the assessment of the probability of malignancy than for BIRADS assessment comparing to MX alone. The potential clinical applications are the clarification of mammographically equivocal lesions, the detection of occult lesions on standard mammography, particularly in dense breast, the determination of the extent of disease, the assessment of recurrent disease and the monitoring of the response to chemotherapy. CEDM should result in a simple way to enhance the detection and the characterization of breast lesions.
10. Digital hum filtering
Knapp, R.W.; Anderson, N.L.
1994-01-01
Data may be overprinted by a steady-state cyclical noise (hum). Steady-state indicates that the noise is invariant with time; its attributes, frequency, amplitude, and phase, do not change with time. Hum recorded on seismic data usually is powerline noise and associated higher harmonics; leakage from full-waveform rectified cathodic protection devices that contain the odd higher harmonics of powerline frequencies; or vibrational noise from mechanical devices. The fundamental frequency of powerline hum may be removed during data acquisition with the use of notch filters. Unfortunately, notch filters do not discriminate signal and noise, attenuating both. They also distort adjacent frequencies by phase shifting. Finally, they attenuate only the fundamental mode of the powerline noise; higher harmonics and frequencies other than that of powerlines are not removed. Digital notch filters, applied during processing, have many of the same problems as analog filters applied in the field. The method described here removes hum of a particular frequency. Hum attributes are measured by discrete Fourier analysis, and the hum is canceled from the data by subtraction. Errors are slight and the result of the presence of (random) noise in the window or asynchrony of the hum and data sampling. Error is minimized by increasing window size or by resampling to a finer interval. Errors affect the degree of hum attenuation, not the signal. The residual is steady-state hum of the same frequency. ?? 1994.
11. Dynamic graded subtraction: a simple method to background correct and display multicompartmental radiopharmaceutical scintigrams
Tuscan, M.J.; Wahl, R.L.; Botti, J.
1985-09-01
A common procedure to enhance the localization of a poorly localized radiopharmaceutical is to mimic and subtract its undesirable component with a second radionuclide of a different photopeak that is physiologic nonspecific. Determination of the exact amount of the nonspecific radionuclide to subtract in a single step, however, is difficult. The authors describe the use of a simple method to enhance an image of a poorly localized radiopharmaceutical by incrementally subtracting another image of a specific radiopharmaceutical that mimics the objectionable image data and displays the corrected image series in cinematic mode. This method of image correction and dynamic display may be useful for a variety of procedures in which there is a significant nonspecific component of the radiotracer such as in radiolabeled antibodies, or to perform selective compartmental or organ subtraction in the case of a mixed specificity radiopharmaceutical.
12. Adaptive multiple subtraction with wavelet-based complex unary Wiener filters
Ventosa, Sergi; Huard, Irène; Pica, Antonio; Rabeson, Hérald; Ricarte, Patrice; Duval, Laurent
2011-01-01
Multiple attenuation is a crucial task in seismic data processing because multiples usually cover primaries from fundamental reflectors. Predictive multiple suppression methods remove these multiples by building an adapted model, aiming at being subtracted from the original signal. However, before the subtraction is applied, a matching filter is required to minimize amplitude differences and misalignments between actual multiples and their prediction, and thus to minimize multiples in the input dataset after the subtraction. In this work we focus on the subtraction element. We propose an adaptive multiple removal technique in a 1-D complex wavelet frame combined with a non-stationary adaptation performed via single-sample (unary) Wiener filters, consistently estimated on overlapping windows in the transformed domain. This approach greatly simplifies the matching filter estimation and, despite its simplicity, compares promisingly with standard adaptive 2-D methods, both in terms of results and retained speed a...
13. Digital Libraries
Papy, Fabrice
2008-01-01
Of vital interest to all librarians and information specialists, this book presents all aspects of the effects of digitization of today's and tomorrow's libraries. From social to technical issues, Digital Libraries includes chapters on the growth of the role of librarian, the reader experience, cataloging, search engines, OPAC, law, ergonomic studies, and the future of libraries.
14. Digital Audiobooks:
Have, Iben; Pedersen, Birgitte Stougaard
Audiobooks are rapidly gaining popularity with widely accessible digital downloading and streaming services. The paper is framing how the digital audiobook expands and changes the target groups for book publications and how it as an everyday activity is creating new reading experiences, places...
15. Tailed pooled suppression subtractive hybridization (PSSH) adaptors do not alter efficiency.
Gerrish, Robert S; Gill, Steven R
2010-11-01
Suppression Subtractive Hybridization (SSH) and its derivative, Pooled Suppression Subtractive hybridization (PSSH), are powerful tools used to study variances larger than ~100 bp in prokaryotic genome structure. The initial steps involve ligating an oligonucleotide of known sequence (the "adaptor") to a fragmented genome to facilitate amplification, subtraction and downstream sequencing. SSH results in the creation of a library of unique DNA fragments which have been traditionally analyzed via Sanger sequencing. Numerous next generation sequencing technologies have entered the market yet SSH is incompatible with these platforms. This is due to the high level of sequence conservation of the oligonucleotide used for SSH. This rigid adherence is partly because it has yet to be determined if alteration of this oligonucleotide will have a deleterious impact on subtraction efficiency. The subtraction occurs when non-unique fragments are inhibited by a secondary self-pairing structure which requires exact nucleotide sequence. We determine if appending custom sequence to the 5' terminal ends of these oligonucleotides during the nested PCR stages of PSSH will reduce subtraction efficiency. We compare a pool of ten S. aureus clinical isolates with a standard PSSH and custom tailed-PSSH. We detected no statistically significant difference between their subtraction efficiencies. Our observations suggest that the adaptor's terminal ends may be labeled during the nested PCR step. This produces libraries labeled with custom sequence. This does not lead to loss of subtraction efficiency and would be invaluable for groups wishing to combine SSH or PSSH with their own downstream applications, such as a high throughput sequencing platform.
16. Design of a Floating-Point Fused Add-Subtract Unit Using Verilog
Mayank Sharma,
2013-06-01
Full Text Available A floating-point (FP fused add-subtract unit is presented that performs simultaneous floating-point operation of add-subtract on a common pair of single-precision data at the same time that it takes to perform in a single addition with a conventional floating-point adder. The system was placed and routed in 45nm process so that there will be less consumption of memory as well as power.
17. Diversity Suppression-Subtractive Hybridization Array for Profiling Genomic DNA Polymorphisms
2006-01-01
Genomic DNA polymorphisms are very useful for tracing genetic traits and studying biological diversity among species. Here, we present a method we call the "diversity suppression-subtractive hybridization array" for effectively profiling genomic DNA polymorphisms. The method first obtains the subtracted gDNA fragments between any two species by suppression subtraction hybridization (SSH) to establish a subtracted gDNA library,from which diversity SSH arrays are created with the selected subtracted clones. The diversity SSH array hybridizes with the DIG-labeled genomic DNA of the organism to be assayed. Six closely related Dendrobium species were studied as model samples. Four Dendrobium species as testers were used to perform SSH. A total of 617 subtracted positive clones were obtained from four Dendrobium species, and the average ratio of positive clones was 80.3%. We demonstrated that the average percentage of polymorphic fragments of pairwise comparisons of four Dendrobium species was up to 42.4%. A dendrogram of the relatedness of six Dendrobium species was produced according to their polymorphic profiles. The results revealed that the diversity SSH array is a highly effective platform for profiling genomic DNA polymorphisms and dendrograms.
18. Young children's use of derived fact strategies in addition and subtraction
Ann eDowker
2014-01-01
19. Value of blood-pool subtraction in cardiac indium-111-labeled platelet imaging
Machac, J.; Vallabhajosula, S.; Goldman, M.E.; Goldsmith, S.J.; Palestro, C.; Strashun, A.; Vaquer, R.; Phillips, R.A.; Fuster, V. (Mt. Sinai Medical Center, New York, NY (USA))
1989-09-01
Blood-pool subtraction has been proposed to enhance {sup 111}In-labeled platelet imaging of intracardiac thrombi. We tested the accuracy of labeled platelet imaging, with and without blood-pool subtraction, in ten subjects with cardiac thrombi of varying age, eight with endocarditis being treated with antimicrobial therapy and ten normal controls. Imaging was performed early after labeled platelet injection (24 hr or less) and late (48 hr or more). Blood-pool subtraction was carried out. All images were graded subjectively by four experienced, blinded readers. Detection accuracy was measured by the sensitivity at three fixed levels of specificity estimated from receiver operator characteristic curve analysis and tested by three-way analysis of variance. Detection accuracy was generally improved on delayed images. Blood-pool subtraction did not improve accuracy. Although blood-pool subtraction increased detection sensitivity, this was offset by decreased specificity. For this population studied, blood-pool subtraction did not improve subjective detection of abnormal platelet deposition by 111In platelet imaging.
20. The sixth data release of the Sloan Digital Sky Survey
Adelman-McCarthy, Jennifer K.; Agüeros, Marcel A.; Allam, Sahar S.; Prieto, Carlos Allende; Anderson, Kurt S. J.; Anderson, Scott F.; Annis, James; Bahcall, Neta A.; Bailer-Jones, C. A. L.; Baldry, Ivan K.; Barentine, J. C.; Bassett, Bruce A.; Becker, Andrew C.; Beers, Timothy C.; Bell, Eric F.
2008-01-01
This paper describes the Sixth Data Release of the Sloan Digital Sky Survey. With this data release, the imaging of the northern Galactic cap is now complete. The survey contains images and parameters of roughly 287 million objects over 9583 deg^2, including scans over a large range of Galactic latitudes and longitudes. The survey also includes 1.27 million spectra of stars, galaxies, quasars, and blank sky (for sky subtraction) selected over 7425 deg^2. This release includes much more stella...
1. FPGA-specific decimal sign-magnitude addition and subtraction
Vázquez, Martín; Todorovich, Elías
2016-07-01
The interest in sign-magnitude (SM) representation in decimal numbers lies in the IEEE 754-2008 standard, where the significand in floating-point numbers is coded as SM. However, software implementations do not meet performance constraints in some applications and more development is required in programmable logic, a key technology for hardware acceleration. Thus, in this work, two strategies for SM decimal adder/subtractors are studied and six new Field Programmable Gate Array (FPGA)-specific circuits are derived from these strategies. The first strategy is based on ten's complement (C10) adder/subtractors and the second one is based on parallel computation of an unsigned adder and an unsigned subtractor. Four of these alternative circuits are useful for at least one area-time-trade-off and specific operand size. For example, the fastest SM adder/subtractor for operand sizes of 7 and 16 decimal digits is based on the second proposed strategy with delays of 3.43 and 4.33 ns, respectively, but the fastest circuit for 34-digit operands is one of the three specific implementations based on C10 adder/subtractors with a delay of 4.65 ns.
Zupancic, Tadeja; Verbeke, Johan; Achten, Henri
2016-01-01
. With this paper we intend to initiate a discussion in the eCAADe community to reflect and develop ideas in order to develop digital leadership skills amongst the membership. This paper introduces some important aspects, which may be valuable to look into when developing digital leadership skills.......Leadership is an important quality in organisations. Leadership is needed to introduce change and innovation. In our opinion, in architectural and design practices, the role of leadership has not yet been sufficiently studied, especially when it comes to the role of digital tools and media...
3. Digital holography
Picart, Pascal
2013-01-01
This book presents a substantial description of the principles and applications of digital holography.The first part of the book deals with mathematical basics and the linear filtering theory necessary to approach the topic. The next part describes the fundamentals of diffraction theory and exhaustively details the numerical computation of diffracted fields using FFT algorithms. A thorough presentation of the principles of holography and digital holography, including digital color holography, is proposed in the third part.A special section is devoted to the algorithms and method
4. Digital electronics
Morris, John
2013-01-01
An essential companion to John C Morris's 'Analogue Electronics', this clear and accessible text is designed for electronics students, teachers and enthusiasts who already have a basic understanding of electronics, and who wish to develop their knowledge of digital techniques and applications. Employing a discovery-based approach, the author covers fundamental theory before going on to develop an appreciation of logic networks, integrated circuit applications and analogue-digital conversion. A section on digital fault finding and useful ic data sheets completes th
5. DIGITAL ASSESSMENTS
Nielsen, Kurt Gammelgaard; Petersen, Lise
2013-01-01
In accordance with The Danish eGOVERNMENT strategy 2011-2015 digital assessment and exam should be implemented at all Danish universities by the end of 2013. University of Southern Denmark (SDU) decided to start the implementation in May 2010.By the exam term of January 2013, the implementation proved successful, and close to completion. The majority of assessments at all of the 5 faculties and 5 campuses were digital, and students had handed in a total of 17.021 digital assessments.On the ba...
Zupancic, Tadeja; Verbeke, Johan; Achten, Henri
2016-01-01
Leadership is an important quality in organisations. Leadership is needed to introduce change and innovation. In our opinion, in architectural and design practices, the role of leadership has not yet been sufficiently studied, especially when it comes to the role of digital tools and media....... With this paper we intend to initiate a discussion in the eCAADe community to reflect and develop ideas in order to develop digital leadership skills amongst the membership. This paper introduces some important aspects, which may be valuable to look into when developing digital leadership skills....
7. Digital Insights
Knudsen, Gry Høngsmark
and practices with digital media, when they meet and interpret advertising. Through studies of advertising response on YouTube and experiments with consumers’ response to digitally manipulated images, the dissertation shows how digital media practices facilitate polysemic and socially embedded advertising......, by incorporating media as both channel, frame, and apparatus for advertising response, the dissertation brings into attention that more aspects than the text-reader relationship influence ad response. Finally, the dissertation proposes the assemblage approach for exploring big data in consumer culture research...
8. Detectability of simulated vessels by computed radiography and digital fluorography
Misumi, Wataru; Yoshioka, Senya; Korogi, Yukunori; Takahashi, Mutsumasa (Kumamoto Univ. (Japan). School of Medicine); Higashida, Yoshiharu
1990-05-01
Phantom studies were carried out to determine the ability to digital subtraction angiography (DSA), using either Fuji computed radiography (CR) or digital fluorography (DF) system, to detect the simulated vessels. The assessment of detectability was based on observer performance techniques. DFDSA was superior to CRDSA. Detectability of CRDSA was influenced by the incident X-ray exposures. Even though it was improved by contrast enhancement, the magnitude of improvement was dependent upon the incident X-ray exposures and vessel size. (N.K.).
9. Digital fabrication
2012-01-01
The Winter 2012 (vol. 14 no. 3) issue of the Nexus Network Journal features seven original papers dedicated to the theme “Digital Fabrication”. Digital fabrication is changing architecture in fundamental ways in every phase, from concept to artifact. Projects growing out of research in digital fabrication are dependent on software that is entirely surface-oriented in its underlying mathematics. Decisions made during design, prototyping, fabrication and assembly rely on codes, scripts, parameters, operating systems and software, creating the need for teams with multidisciplinary expertise and different skills, from IT to architecture, design, material engineering, and mathematics, among others The papers grew out of a Lisbon symposium hosted by the ISCTE-Instituto Universitario de Lisboa entitled “Digital Fabrication – A State of the Art”. The issue is completed with four other research papers which address different mathematical instruments applied to architecture, including geometric tracing system...
10. Digital Humanities
Brügger, Niels
2016-01-01
the humanities for decades, starting with research fields such as humanities computing or computational linguistics in the 1950s, and later new media studies and internet studies. The historical development of digital humanities has been characterized by a focus on three successive, but co-existing types......Digital humanities is an umbrella term for theories, methodologies, and practices related to humanities scholarship that use the digital computer as an integrated and essential part of its research and teaching activities. The computer can be used for establishing, finding, collecting......, and preserving material to study, as an object of study in its own right, as an analytical tool, or for collaborating, and for disseminating results. The term "digital humanities" was coined around 2001, and gained currency within academia in the following years. However, computers had been used within...
11. Digital Snaps
Sandbye, Mette; Larsen, Jonas
The New Face of Snapshot Photography / Jonas Larsen and Mette Sandbye -- pt. I. IMAGES ON WEB 2.0 AND THE CAMERA PHONE -- ch. 1. Overlooking, Rarely Looking and Not Looking / Martin Lister -- ch. 2. The (Im)mobile Life of Digital Photographs: The Case of Tourist Photography / Jonas Larsen -- ch. 3....... Distance as the New Punctum / Mikko Villi -- pt. II. FAMILY ALBUMS IN TRANSITION -- ch. 4. How Digital Technologies Do Family Snaps, Only Better / Gillian Rose -- ch. 5. Friendship Photography: Memory, Mobility and Social Networking / Joanne Garde-Hansen -- ch. 6. Play, Process and Materiality in Japanese...... Purikura Photography / Mette Sandbye -- ch. 7. 'Buying an Instrument Does Not Necessarily Make You a Musician': Studio Photography and the Digital Revolution / Sigrid Lien -- pt. III. NEW PUBLIC FORMS -- ch. 8 Paparazzi Photography, Seriality and the Digital Photo Archive / Anne Jerslev and Mette Mortensen...
12. Becoming digital
Pors, Anja Svejgaard
2015-01-01
The purpose of this paper is to examine the impact of e-government reforms on street-level bureaucrats’ professionalism and relation to citizens, thus demonstrating how the bureaucratic encounter unfolds in the digital era. Design/methodology/approach: The paper is based on an ethnographic study....... An ethnographic account of how digital reforms are implemented in practice shows how street-level bureaucrat’s classic tasks such as specialized casework are being reconfigured into educational tasks that promote the idea of “becoming digital”. In the paper, the author argues that the work of “becoming digital....... Originality/value: The study contributes to ethnographic research in public administration by combining two separate subfields, e-government and street-level bureaucracy, to discern recent transformations in public service delivery. In the digital era, tasks, control and equality are distributed in ways...
13. Digital Steganography
KOCIÁNOVÁ, Helena
2009-01-01
Digital steganography is a technique for hiding data mostly into multimedia files (images, audio, video). With the development of information technology this technique has found its use in the field of copyright protection and secret data transfer, could be even applied in places where is limited possibility of using cryptography (e. g. by law). This thesis gives insight into digital steganography and contains an application using this technique.
14. Digital watermark
Jasna Maver
2004-01-01
The huge amount of multimedia contents available on the World-Wide-Web is beginning to raise the question of their protection. Digital watermarking is a technique which can serve various purposes, including intellectual property protection, authentication and integrity verification, as well as visible or invisible content labelling of multimedia content. Due to the diversity of digital watermarking applicability, there are many different techniques, which can be categorised according to diffe...
15. Evaluation of diagnostic ability of CCD digital radiography in the detection of incipient dental caries
Lee, Wan; Lee, Byung Do [Wonkwang University College of Medicine, Iksan (Korea, Republic of)
2003-03-15
16. Subtraction-multiphase-CT unbeneficial for early detection of colorectal liver metastases
Meijerink, Martijn R., E-mail: [email protected] [Department of Radiology, Vrije Universiteit Medisch Centrum, Amsterdam (Netherlands); Waesberghe, Jan Hein T.M. van; Golding, Richard P. [Department of Radiology, Vrije Universiteit Medisch Centrum, Amsterdam (Netherlands); Weide, Lineke van der [Master of Oncology Program, Vrije Universiteit Medisch Centrum, Amsterdam (Netherlands); Tol, Petrousjka van den [Department of Surgical Oncology, Vrije Universiteit Medisch Centrum, Amsterdam (Netherlands); Meijer, Sybren [Master of Oncology Program, Vrije Universiteit Medisch Centrum, Amsterdam (Netherlands); Kuijk, Cornelis van [Department of Radiology, Vrije Universiteit Medisch Centrum, Amsterdam (Netherlands)
2010-06-15
Purpose: To assess the value of multiphase-subtraction-CT for early detection of colorectal-liver-metastases (CRLM). Methods and materials: In 50 patients suspected of CRLM a routine pre-operative 4-phase-CT-scan of the upper abdomen was obtained. All 12 possible image subtractions between two different phases were constructed applying 3D-image-registration to decrease distortion artefacts induced by differences in inspiration volume. Two experienced radiologists initially reviewed the conventional 4-phase-CT for malignant and/or benign appearing lesions and at least 1-month hereafter the same 4-phase-CT now including the subtracted images. The results were compared to histology reports or to a combination of surgical exploration and intraoperative ultrasound together with results from pre-operative PET and follow-up examinations. Results: Although an additional number of 31 malignant appearing lesions were detected on the subtraction images, none proved to represent a true CRLM. Interobserver agreement ({kappa}) decreased from 0.627 (good) to 0.418 (fair). Conclusion: Adding linearly co-registered subtraction-CT images to a conventional 4-phase-CT protocol does not improve detection of CRLM.
17. Identification of differentially expressed radiation-induced genes in cervix carcinoma cells using suppression subtractive hybridization
Kim, Jun Sang; Lee, Young Sook; Lee, Jeung Hoon; Lee, Woong Hee; Seo, Eun Young; Cho, Moon June [Chungnam National University, Daejeon (Korea, Republic of)
2005-03-15
A number of genes and their products are induced early or late following exposure of cells to ionizing radiation. These radiation-induced genes have various effects of irradiated cells and tissues. Suppression subtractive hybridization (SSH) based on PCR was used to identify the differentially expressed genes by radiation in cervix carcinoma cells. Total RNA and poly (A){sup +} mRNA were isolated from irradiated and non-irradiated HeLa cells. Forward-and reverse-subtracted cDNA libraries were constructed using SSH. Eighty-eight clones of each were used to randomly select differentially expressed genes using reverse Northern blotting (dot blot analysis). Northern blotting was used to verify the screened genes. Of the 176 clones, 10 genes in the forward-subtracted library and 9 genes in the reverse-subtracted library were identified as differentially expressed radiation-induced genes by PCR-select differential screening. Three clones from the forward-subtracted library were confirmed by Northern blotting, and showed increased expression in a dose-dependent manner, including a telomerase catalytic subunit and sodium channel-like protein gene, and an ESTs (expressed sequence tags) gene. We identified differentially expressed radiation-induced genes with low-abundance genes with SSH, but further characterization of theses genes are necessary to clarify the biological functions of them.
18. L5 pedicle subtraction osteotomy for high-grade isthmic spondylolisthesis.
Radcliff, Kristen E; Jakoi, Andre M
2015-04-01
To the authors' knowledge, this is the first article to present a pedicle subtraction osteotomy in the lumbar spine to correct and stabilize a high-grade isthmic spondylolisthesis, which poses many challenges with regard to treatment options and outcomes. The optimal surgical treatment for high-grade spondylolisthesis is controversial, but the goals of treatment are to stabilize the affected spinal levels and to decompress the neural elements. A pedicle subtraction osteotomy is a reconstructive procedure that addresses fixed sagittal imbalance by increasing lumbar lordosis through posterior spinal column shortening. The authors report a 46-year-old patient with chronic, progressively worsening back and leg radiculopathy accompanied by sagittal plane malalignment and for which a pedicle subtraction osteotomy was performed. The procedure yielded stabilization of the patient's lumbar spondylolisthesis and sagittal plane alignment was restoration. At 3 months postoperatively, the patient's pain had fully resolved and her motor and neurologic examination exhibited no deficits. At 24 months postoperatively, she was still symptom-free and ambulating without assistance. This report is the first documented successful pedicle subtraction osteotomy in the treatment of high-grade spondylolisthesis. This report indicates that certain patient populations may be amenable to pedicle subtraction osteotomy as a treatment option for pathology involving high-grade isthmic spondylolisthesis.
19. Comprehensive Study and Comparative Analysis of Different Types of Background Sub-traction Algorithms
Priyank Shah
2014-07-01
Full Text Available There are many methods proposed for Back-ground Subtraction algorithm in past years. Background subtraction algorithm is widely used for real time moving object detection in video surveillance system. In this paper we have studied and implemented different types of meth-ods used for segmentation in Background subtraction algo-rithm with static camera. This paper gives good under-standing about procedure to obtain foreground using exist-ing common methods of Background Subtraction, their complexity, utility and also provide basics which will useful to improve performance in the future . First, we have explained the basic steps and procedure used in vision based moving object detection. Then, we have debriefed the common methods of background subtraction like Sim-ple method, statistical methods like Mean and Median filter, Frame Differencing and W4 System method, Running Gaussian Average and Gaussian Mixture Model and last is Eigenbackground Model. After that we have implemented all the above techniques on MATLAB software and show some experimental results for the same and compare them in terms of speed and complexity criteria.
20. Automated contralateral subtraction of dental panoramic radiographs for detecting abnormalities in paranasal sinus
Hara, Takeshi; Mori, Shintaro; Kaneda, Takashi; Hayashi, Tatsuro; Katsumata, Akitoshi; Fujita, Hiroshi
2011-03-01
Inflammation in the paranasal sinus is often observed in seasonal allergic rhinitis or with colds, but is also an indication for odontogenic tumors, carcinoma of the maxillary sinus or a maxillary cyst. The detection of those findings in dental panoramic radiographs is not difficult for radiologists, but general dentists may miss the findings since they focus on treatments of teeth. The purpose of this work is to develop a contralateral subtraction method for detecting the odontogenic sinusitis region on dental panoramic radiographs. We developed a contralateral subtraction technique in paranasal sinus region, consisting of 1) image filtering of the smoothing and sobel operation for noise reduction and edge extraction, 2) image registration of mirrored image by using mutual information, and 3) image display method of subtracted pixel data. We employed 56 cases (24 normal and 32 abnormal). The abnormal regions and the normal cases were verified by a board-certified radiologist using CT scans. Observer studies with and without subtraction images were performed for 9 readers. The true-positive rate at a 50% confidence level in 7 out of 9 readers was improved, but there was no statistical significance in the difference of area-under-curve (AUC) in each radiologist. In conclusion, the contralateral subtraction images of dental panoramic radiographs may improve the detection rate of abnormal regions in paranasal sinus.
1. A practical method for randoms subtraction in volume imaging PET from detector singles countrate measurements
Smith, R.J.; Karp, J.S. [Univ. of Pennsylvania, Philadelphia, PA (United States). Dept. of Radiology
1996-06-01
Randoms subtraction in a volume imaging PET scanner is a significant problem due to the high singles countrates experienced. The delayed coincidence method requires double counting of randoms events and results in a lowered countrate capability. Calculations based on detector singles countrates require complex corrections for countrate dependent livetime and event acceptance due to the camera coincidence processing between the detector and rebinned randoms countrates. The profile distribution method has been used to estimate and subtract both scatter and randoms background but this method is a compromise and couples these 2 sources of background together. In order to avoid these problems and provide accurate subtraction of both the distribution and magnitude of randoms contamination in the scan data the authors have developed an alternative singles based method. The singles distributions are measured across the detectors and are used to construct a randoms distribution sinogram. This distribution is scaled to the appropriate rebinned randoms countrate by means of a lookup table of randoms countrate vs detector singles countrate, generated from phantom calibrations. The advantages of performing randoms subtraction by this method are: (1) there is no increase in camera deadtime, (2) the method compensates for nonuniformities in randoms distributions due to both the activity distribution and nonuniform geometric response of the camera for on and off bankpairs, and (3) it deals with randoms subtraction independently of scatter so that different scatter correction routines may then be applied to the data.
2. Tumor scintigraphy by the method for subtracting the initial image with technetium-99m labeled antibody
Karube, Yoshiharu; Katsuno, Kentaro; Ito, Sanae; Matsunaga, Kazuhisa; Takata, Jiro [Fukuoka Univ. (Japan). Faculty of Pharmaceutical Sciences; Kuroki, Masahide; Murakami, Masaaki; Matsuoka, Yuji
1999-12-01
The method for subtracting the initial image from the localization image was evaluated for radioimmunoscintigraphy of tumors with technetium-99m (Tc-99m) labeled antibodies. Monoclonal antibodies were parental mouse and mouse-human chimeric antibodies to carcinoembryonic antigen (CEA), designated F11-39 and ChF11-39, respectively, both of which have been found to discriminate CEA in tumor tissues from the CEA-related antigens. After reduction of the intrinsic disulfide bonds, these antibodies were labeled with Tc-99m. In vivo studies were performed on athymic nude mice bearing the human CEA-producing gastric carcinoma xenografts. Though biodistribution results showed selective and progressive accumulation of Tc-99m labeled antibodies at the tumor site, high radioactivity in blood was inappropriate for scintigraphic visualization of the tumors within a few hours. We examined the subtraction of the initial Tc-99m image from the Tc-99m localization image after a few hours. Subtracted images of the same count reflected the in vivo behavior of the Tc-99m radioactivity. The subtracted scintigrams revealed excellent tumor images with no significant extrarenal background. Visualization of the tumor site was dependent on antigen-specific binding and nonspecific exudation. These results demonstrate that a method of subtraction of the initial image may serve as a potentially useful diagnostic method for an abnormal site for agents with a low pharmacokinetic value. (author)
3. Digital Humanities and networked digital media
Finnemann, Niels Ole
2014-01-01
This article discusses digital humanities and the growing diversity of digital media, digital materials and digital methods. The first section describes the humanities computing tradition formed around the interpretation of computation as a rule-based process connected to a concept of digital materials centred on the digitisation of non-digital, finite works, corpora and oeuvres. The second section discusses “the big tent” of contemporary digital humanities. It is argued that there can be no ...
4. Oxaliplatin Induced Digital Ischemia and Necrosis
Kubilay Karabacak
2015-01-01
Full Text Available Introduction. Digital ischemia is a rare complication of several chemotherapeutic medications. We aimed to present a patient with digital ischemia, secondary to a new generation chemotherapeutic drug, oxaliplatin. Case Report. 62-year-old woman presented to our department with severe pain, paresthesia, and distal acrocyanosis on her right hand fingertips. Her complaints started five days after the third cycle of a chemotherapy protocol consisting of 5-fluorourasil (5-FU, folinic acid, and oxaliplatin due to advanced colon carcinoma. On physical examination, hemorrhagic and partly ulcerative lesions were detected at her right hand fingertips. Radial and ulnar pulses were absent at affected side. Digital subtraction angiography revealed severe vascular resistance in the affected extremity. Iloprost trometamol treatment was started with the dosage of 1 ng/kg/min. In addition, low-molecule-weight heparin was used for preventing possible microemboli. Symptomatic relief was provided after five days, and patient was discharged on 7th day of treatment. Discussion. The pathogenesis of oxaliplatin induced vascular toxicity remains unclear. Endothelial damage, increased adherence of platelets, deposition of immune complexes as an immunologic effect of oxaliplatin, and hypercoagulable state may be the reason for arterial thrombosis, digital microemboli, possible digital ischemia, and their several consequences.
5. Digital Communication Using Multi-mode Chaotic Lasers
WU Liang; ZHU Shi-Qun
2004-01-01
The digital communication in a system of two multi-mode solid state chaotic lasers is investigated theoretically. If the usual method working well in a single-mode laser system is applied to a multi-mode laser system, the memory effect of the two nearest digits can cause high rate of mistakes when the digits are decoded through the subtraction of receiver output from the transmittal. By introducing the deviations of two nearest maximum and minimum fluctuations of the signal to decode the digit, the message can be decoded correctly. Also, this communication method does not critically depend on the quality of the chaotic synchronization of the two multi-mode lasers.
6. Perceiving fingers in single-digit arithmetic problems
Ilaria eBerteletti
2015-03-01
Full Text Available In this study, we investigate in children the neural underpinnings of finger representation and finger movement involved in single-digit arithmetic problems. Evidence suggests that finger representation and finger-based strategies play an important role in learning and understanding arithmetic. Because different operations rely on different networks, we compared activation for subtraction and multiplication problems in independently localized finger somatosensory and motor areas and tested whether activation was related to skill. Brain activations from children between 8 and 13 years of age revealed that only subtraction problems significantly activated finger motor areas, suggesting reliance on finger-based strategies. In addition, larger subtraction problems yielded greater somatosensory activation than smaller problems, suggesting a greater reliance on finger representation for larger numerical values. Interestingly, better performance in subtraction problems was associated with lower activation in the finger somatosensory area. Our results support the importance of fine-grained finger representation in arithmetical skill and are the first neurological evidence for a functional role of the somatosensory finger area in proficient arithmetical problem solving, in particular for those problems requiring quantity manipulation. From an educational perspective, these results encourage investigating whether different finger-based strategies facilitate arithmetical understanding and encourage educational practices aiming at integrating finger representation and finger-based strategies as a tool for instilling stronger numerical sense.
7. Digital watermark
Jasna Maver
2000-01-01
Full Text Available The huge amount of multimedia contents available on the World-Wide-Web is beginning to raise the question of their protection. Digital watermarking is a technique which can serve various purposes, including intellectual property protection, authentication and integrity verification, as well as visible or invisible content labelling of multimedia content. Due to the diversity of digital watermarking applicability, there are many different techniques, which can be categorised according to different criteria. A digital watermark can be categorised as visible or invisible and as robust or fragile. In contrast to the visible watermark where a visible pattern or image is embedded into the original image, the invisible watermark does not change the visual appearance of the image. The existence of such a watermark can be determined only through a watermark ex¬traction or detection algorithm. The robust watermark is used for copyright protection, while the fragile watermark is designed for authentication and integrity verification of multimedia content. A watermark must be detectable or extractable to be useful. In some watermarking schemes, a watermark can be extracted in its exact form, in other cases, we can detect only whether a specific given watermarking signal is present in an image. Digital libraries, through which cultural institutions will make multimedia contents available, should support a wide range of service models for intellectual property protection, where digital watermarking may play an important role.
8. Enrichment of an in vivo phage display repertoire by subtraction for easy identification of pathology biomarkers
karina Vargas Sanchez
2015-03-01
Conclusion. This physical subtraction discarded from a complex repertoire the non-specific selected ligands. STRATEGY 1 Three rounds of in vivo phage peptide selection in EAE female Lewis rats ("EAE repertoire" vs controls ("HEALTHY repertoire". 2 DNA subtraction of the most common sequences between «HEALTHY» and «EAE» phage repertoires to obtain a third EAE specific «SUBTRACTION » phage repertoire. 3 Massive sequencing of the three repertoires and bioinformatic analysis to identify the peptides sequences with high EAE specificity. 4 Biological tests of potential EAE specific phage clones with CNS tissues from EAE and Healthy control rats. 5 Biological tests of the EAE specific peptide and phage clones on the BBB in vitro model (hCMEC/D3 cells under inflammatory conditions (IL-1β stimulation. 6 Target separation and identification by cross-link between the selected phage clones and hMEC/D3 endothelial cells targets under IL-1β stimulation vs controls.
9. [The backgroud sky subtraction around [OIII] line in LAMOST QSO spectra].
Shi, Zhi-Xin; Comte, Georges; Luo, A-Li; Tu, Liang-Ping; Zhao, Yong-Heng; Wu, Fu-Chao
2014-11-01
At present, most sky-subtraction methods focus on the full spectrum, not the particular location, especially for the backgroud sky around [OIII] line which is very important to low redshift quasars. A new method to precisely subtract sky lines in local region is proposed in the present paper, which sloves the problem that the width of Hβ-[OIII] line is effected by the backgroud sky subtraction. The exprimental results show that, for different redshift quasars, the spectral quality has been significantly improved using our method relative to the original batch program by LAMOST. It provides a complementary solution for the small part of LAMOST spectra which are not well handled by LAMOST 2D pipeline. Meanwhile, This method has been used in searching for candidates of double-peaked Active Galactic Nuclei.
10. Spectral Subtraction Approach for Interference Reduction of MIMO Channel Wireless Systems
Tomohiro Ono
2005-08-01
Full Text Available In this paper, a generalized spectral subtraction approach for reducing additive impulsive noise, narrowband signals, white Gaussian noise and DS-CDMA interferences in MIMO channel DS-CDMA wireless communication systems is investigated. The interference noise reduction or suppression is essential problem in wireless mobile communication systems to improve the quality of communication. The spectrum subtraction scheme is applied to the interference noise reduction problems for noisy MIMO channel systems. The interferences in space and time domain signals can effectively be suppressed by selecting threshold values, and the computational load with the FFT is not large. Further, the fading effects of channel are compensated by spectral modification with the spectral subtraction process. In the simulations, the effectiveness of the proposed methods for the MIMO channel DS-CDMA is shown to compare with the conventional MIMO channel DS-CDMA.
11. Perturbative subtraction of lattice artifacts in the computation of renormalization constants
Constantinou, M; Gockeler, M; Horsley, R; Panagopoulos, H; Perlt, H; Rakow, P E L; Schierholz, G; Schiller, A
2012-01-01
The determination of renormalization factors is of crucial importance. They relate the observables obtained on finite, discrete lattices to their measured counterparts in the continuum in a suitable renormalization scheme. Therefore, they have to be computed as precisely as possible. A widely used approach is the nonperturbative Rome-Southampton method. It requires, however, a careful treatment of lattice artifacts. They are always present because simulations are done at lattice spacings $a$ and momenta $p$ with $ap$ not necessarily small. In this paper we try to suppress these artifacts by subtraction of one-loop contributions in lattice perturbation theory. We compare results obtained from a complete one-loop subtraction with those calculated for a subtraction of $O(a^2)$.
12. Optimal fractionation and bioassay plans for isolation of synergistic chemicals: The subtractive-combination method.
Byers, J A
1992-09-01
Studies of chemical ecology of an organism are founded on the isolation and identification of a semiochemical, often comprised of two or more synergistic compounds (each Synergist alone has little activity, but presented together they are bioactive). Chromatographie fractionation and bioassay methods of binary splitting, additive combination, and subtractive combination are compared for efficiency in isolating synergists. Formulas are derived for the latter two methods that calculate the expected number of bioassay tests required for isolation of from two to five synergists from biological extracts with any number of compounds, depending on the number of initial (major) Chromatographic fractions. A computer program based on the formulas demonstrates the superiority of the subtractive-combination method. Simulations with the program were used to determine the optimal number of initial fractions for the additive- and subtractive-combination methods when isolating two to five synergists from extracts of from 25 to 1200 compounds. Methods of bioassay, isolation, identification, and field testing of semiochemicals are discussed.
13. Subtraction of point sources from interferometric radio images through an algebraic forward modeling scheme
Bernardi, G; Ord, S M; Greenhill, L J; Pindor, B; Wayth, R B; Wyithe, J S B
2010-01-01
We present a method for subtracting point sources from interferometric radio images via forward modeling of the instrument response and involving an algebraic nonlinear minimization. The method is applied to simulated maps of the Murchison Wide-field Array but is generally useful in cases where only image data are available. After source subtraction, the residual maps have no statistical difference to the expected thermal noise distribution at all angular scales, indicating high effectiveness in the subtraction. Simulations indicate that the errors in recovering the source parameters decrease with increasing signal-to-noise ratio, which is consistent with the theoretical measurement errors. In applying the technique to simulated snapshot observations with the Murchison Wide-field Array, we found that all 101 sources present in the simulation were recovered with an average position error of 10 arcsec and an average flux density error of 0.15%. This led to a dynamic range increase of approximately 3 orders of m...
14. The effects of camera jitter for background subtraction algorithms on fused infrared-visible video streams
Becker, Stefan; Scherer-Negenborn, Norbert; Thakkar, Pooja; Hübner, Wolfgang; Arens, Michael
2016-10-01
This paper is a continuation of the work of Becker et al.1 In their work, they analyzed the robustness of various background subtraction algorithms on fused video streams originating from visible and infrared cameras. In order to cover a broader range of background subtraction applications, we show the effects of fusing infrared-visible video streams from vibrating cameras on a large set of background subtraction algorithms. The effectiveness is quantitatively analyzed on recorded data of a typical outdoor sequence with a fine-grained and accurate annotation of the images. Thereby, we identify approaches which can benefit from fused sensor signals with camera jitter. Finally conclusions on what fusion strategies should be preferred under such conditions are given.
15. Enhancing quantum entanglement for continuous variables by a coherent superposition of photon subtraction and addition
Lee, Su-Yong; Kim, Ho-Joon [Department of Physics, Texas A and M University at Qatar, P.O. Box 23874, Doha (Qatar); Ji, Se-Wan [School of Computational Sciences, Korea Institute for Advanced Study, Seoul 130-012 (Korea, Republic of); Nha, Hyunchul [Department of Physics, Texas A and M University at Qatar, P.O. Box 23874, Doha (Qatar); Institute fuer Quantenphysik, Universitaet Ulm, D-89069 Ulm (Germany)
2011-07-15
We investigate how the entanglement properties of a two-mode state can be improved by performing a coherent superposition operation ta+ra{sup {dagger}} of photon subtraction and addition, proposed by Lee and Nha [Phys. Rev. A 82, 053812 (2010)], on each mode. We show that the degree of entanglement, the Einstein-Podolsky-Rosen-type correlation, and the performance of quantum teleportation can be all enhanced for the output state when the coherent operation is applied to a two-mode squeezed state. The effects of the coherent operation are more prominent than those of the mere photon subtraction a and the addition a{sup {dagger}} particularly in the small-squeezing regime, whereas the optimal operation becomes the photon subtraction (case of r=0) in the large-squeezing regime.
16. Digital Humanities and networked digital media
Finnemann, Niels Ole
2014-01-01
This article discusses digital humanities and the growing diversity of digital media, digital materials and digital methods. The first section describes the humanities computing tradition formed around the interpretation of computation as a rule-based process connected to a concept of digital...... materials centred on the digitisation of non-digital, finite works, corpora and oeuvres. The second section discusses “the big tent” of contemporary digital humanities. It is argued that there can be no unifying interpretation of digital humanities above the level of studying digital materials with the help...
17. Digital Relationships
Ledborg Hansen, Richard
-‐Jones, 2011) for increases in effectiveness and efficiency we indiscriminately embrace digital communication and digitized information dissemination with enthusiasm – at the risk of ignoring the potentially dark side of technology. However, technology also holds a promise for better understanding precisely...... of residual deposits from technology in organizations and its effect on individuals ability to connect to one another. Based on the case study the paper describes indications and suggests potential implication hereof. Given the inherent enhancement possibilities of technology our expectation for entertainment......-rich information and highly interesting communication are sky-high and rising. With a continuous increase in digitized communication follows a decrease in face-to-face encounters and our ability to engage in inter-personal relationships are suffering for it (Davis, 2013). The behavior described in this paper...
18. Digital Creativity
Petersson Brooks, Eva; Brooks, Anthony Lewis
2014-01-01
This paper reports on a study exploring the outcomes from children’s play with technology in early childhood learning practices. The paper addresses questions related to how digital technology can foster creativity in early childhood learning environments. It consists of an analysis of children......’s interaction with the KidSmart furniture focusing on digital creativity potentials and play values suggested by the technology. The study applied a qualitative approach and included125 children (aged three to five), 10 pedagogues, and two librarians. The results suggests that educators should sensitively...... consider intervening when children are interacting with technology, and rather put emphasize into the integration of the technology into the environment and to the curriculum in order to shape playful structures for children’s digital creativity....
19. Subtraction of Spurious Centre-of-Mass Motion in Quark Delocalization and Colour Screening Model
CHEN Ling-Zhi; PANG Hou-Rong; HUANG Hong-Xia; PING Jia-Lun; WANG Fan
2007-01-01
The quark delocalization colour screening model provides an alternative approach for the NN intermediate range attraction, which is attributed to the σ meson exchange in the meson exchange and chiral quark model.However the quark delocalization induces the spurious centre-of-mass motion (CMM). A method for subtracting the spurious CMM proposed before is applied to the new scattering calculation. The subtraction of the spurious CMM results in an additional NN attraction. The NN scattering data are refitted by a fine tune of the colour screening constant.
20. Intensity Weighted Subtraction Microscopy Approach for Image Contrast and Resolution Enhancement
Korobchevskaya, Kseniya; Peres, Chiara; Li, Zhibin; Antipov, Alexei; Sheppard, Colin J. R.; Diaspro, Alberto; Bianchini, Paolo
2016-05-01
We propose and demonstrate a novel subtraction microscopy algorithm, exploiting fluorescence emission difference or switching laser mode and their derivatives for image enhancement. The key novelty of the proposed approach lies in the weighted subtraction coefficient, adjusted pixel-by-pixel with respect to the intensity distributions of initial images. This method produces significant resolution enhancement and minimizes image distortions. Our theoretical and experimental studies demonstrate that this approach can be applied to any optical microscopy techniques, including label free and non-linear methods, where common super-resolution techniques cannot be used.
1. Similarity renormalization group evolution of N N interactions within a subtractive renormalization scheme
Durães F.O.
2010-04-01
Full Text Available We apply the similarity renormalization group (SRG approach to evolve a nucleon-nucleon (N N interaction in leading-order (LO chiral effective field theory (ChEFT, renormalized within the framework of the subtracted kernel method (SKM. We derive a fixed-point interaction and show the renormalization group (RG invariance in the SKM approach. We also compare the evolution of N N potentials with the subtraction scale through a SKM RG equation in the form of a non-relativistic Callan-Symanzik (NRCS equation and the evolution with the similarity cutoff through the SRG transformation.
2. Real-time optical image subtraction by a holographic shear lens
Rao, V. Venkateswara; Joenathan, C.; Sirohi, R. S.
1985-08-01
A new optical method of image subtraction by employing a holographic shear lens is proposed. The principle underlying this technique is that of optical interference between two sheared fields produced by the holographic shear lens (HSL). Two dissimilar inputs with some common characters are subtracted in real time while keeping the HSL at the Fourier plane of a well corrected lens. The difference is detectable only when zero fringe is obtained in the interferogram. Experimental verification is presented with the results. The basic advantages of this technique are the simplicity in aligning the input transparencies and the real time operation.
3. Higgs boson production in association with a jet using jettiness subtraction
2015-09-01
Full Text Available We use the recently proposed jettiness-subtraction scheme to provide the complete calculation of Higgs boson production in association with a jet in hadronic collisions through next-to-next-to-leading order in perturbative QCD. This method exploits the observation that the N-jettiness event-shape variable completely describes the singularity structure of QCD when final-state colored particles are present. Our results are in agreement with a recent computation of the gg and qg partonic initial states based on sector-improved residue subtraction. We present phenomenological results for both fiducial cross sections and distributions at the LHC.
4. A Feature Subtraction Method for Image Based Kinship Verification under Uncontrolled Environments
Duan, Xiaodong; Tan, Zheng-Hua
2015-01-01
The most fundamental problem of local feature based kinship verification methods is that a local feature can capture the variations of environmental conditions and the differences between two persons having a kin relation, which can significantly decrease the performance. To address this problem...... the feature distance between face image pairs with kinship and maximize the distance between non-kinship pairs. Based on the subtracted feature, the verification is realized through a simple Gaussian based distance comparison method. Experiments on two public databases show that the feature subtraction method...
5. Fotografia digital
Vinicius Cauduro, Flávio; Pontifícia Universidade Católica do Rio Grande do Sul
2008-01-01
Poderíamos talvez definir como sendo fotografia digital toda e qualquer imagem obtida a partir de uma camera obscura, com características ótico-mecânicas variáveis através de princípios puramente analógicos ou por combinação híbrida (analógico/digital), e que seja posteriormente processada em computador e exibida de forma projetada (monitor ou tela) ou imprensa (papel ou filme).
6. Digital photogrammetry
Egels, Yves
2003-01-01
Photogrammetry is the use of photography for surveying primarily and is used for the production of maps from aerial photographs. Along with remote sensing, it represents the primary means of generating data for Geographic Information Systems (GIS). As technology develops, it is becoming easier to gain access to it. The cost of digital photogrammetric workstations are falling quickly and these new tools are therefore becoming accessible to more and more users. Digital Photogrammetry is particularly useful as a text for graduate students in geomantic and is also suitable for people with a good basic scientific knowledge who need to understand photogrammetry, and who wish to use the book as a reference.
7. Digital literacies
Hockly, Nicky; Pegrum, Mark
2014-01-01
Dramatic shifts in our communication landscape have made it crucial for language teaching to go beyond print literacy and encompass the digital literacies which are increasingly central to learners' personal, social, educational and professional lives. By situating these digital literacies within a clear theoretical framework, this book provides educators and students alike with not just the background for a deeper understanding of these key 21st-century skills, but also the rationale for integrating these skills into classroom practice. This is the first methodology book to address not jus
8. Digital communication
Das, Apurba
2010-01-01
""Digital Communications"" presents the theory and application of the philosophy of Digital Communication systems in a unique but lucid form. This book inserts equal importance to the theory and application aspect of the subject whereby the authors selected a wide class of problems. The Salient features of the book are: the foundation of Fourier series, Transform and wavelets are introduces in a unique way but in lucid language; the application area is rich and resemblance to the present trend of research, as we are attached with those areas professionally; a CD is included which contains code
9. Digital filters
Hamming, Richard W
1997-01-01
Digital signals occur in an increasing number of applications: in telephone communications; in radio, television, and stereo sound systems; and in spacecraft transmissions, to name just a few. This introductory text examines digital filtering, the processes of smoothing, predicting, differentiating, integrating, and separating signals, as well as the removal of noise from a signal. The processes bear particular relevance to computer applications, one of the focuses of this book.Readers will find Hamming's analysis accessible and engaging, in recognition of the fact that many people with the s
10. Digitalization Boosting Novel Digital Services for Consumers
Kaisa Vehmas
Full Text Available Digitalization has changed the world. The digital revolution has promoted the Internet, and more recently mobile network infrastructure, as the technological backbone of our society. Digital technologies have become more integrated across all sectors of o ...
11. Digital Methods
Rogers, R.
2013-01-01
In Digital Methods, Richard Rogers proposes a methodological outlook for social and cultural scholarly research on the Web that seeks to move Internet research beyond the study of online culture. It is not a toolkit for Internet research, or operating instructions for a software package; it deals wi
12. Digital Tidbits
Kumaran, Maha; Geary, Joe
2011-01-01
Technology has transformed libraries. There are digital libraries, electronic collections, online databases and catalogs, ebooks, downloadable books, and much more. With free technology such as social websites, newspaper collections, downloadable online calendars, clocks and sticky notes, online scheduling, online document sharing, and online…
13. Digital Tidbits
Kumaran, Maha; Geary, Joe
2011-01-01
Technology has transformed libraries. There are digital libraries, electronic collections, online databases and catalogs, ebooks, downloadable books, and much more. With free technology such as social websites, newspaper collections, downloadable online calendars, clocks and sticky notes, online scheduling, online document sharing, and online…
Precht, H; Gerke, O; Rosendahl, K
2012-01-01
BACKGROUND: New developments in processing of digital radiographs (DR), including multi-frequency processing (MFP), allow optimization of image quality and radiation dose. This is particularly promising in children as they are believed to be more sensitive to ionizing radiation than adults...
15. Digital books.
Wink, Diane M
2011-01-01
In this bimonthly series, the author examines how nurse educators can use the Internet and Web-based computer technologies such as search, communication, and collaborative writing tools; social networking and social bookmarking sites; virtual worlds; and Web-based teaching and learning programs. This article describes digital books.
16. Digital forvaltning
Remmen, Arne; Larsen, Torben; Mosgaard, Mette
2004-01-01
Større effektivitet, bedre service og mere demokrai er blot nogle af forventningerne til indførelse af digital forveltning i kommunerne. Kapitlet giver bland andet svar på spørgsmålene : Hvordan lever kommunerne op hertil i dagligdagen? hvilke virkemidler anvender de? Hvilke barrierer har der været...
17. Digital Batteries
Hubler, Alfred
2009-03-01
The energy density in conventional capacitors is limited by sparking. We present nano-capacitor arrays, where - like in laser diodes and quantum wells [1] - quantization prevents dielectric breakthrough. We show that the energy density and the power/weight ratio are very high, possibly larger than in hydrogen [2]. Digital batteries are a potential clean energy source for cars, laptops, and mobile devices. The technology is related to flash drives. However, because of the high energy density, safety is a concern. Digital batteries can be easily and safely charged and discharged. In the discharged state they pose no danger. Even if a charged digital battery were to explode, it would produce no radioactive waste, no long-term radiation, and probably could be designed to produce no noxious chemicals. We discuss methodologies to prevent shorts and other measures to make digital batteries safe. [1] H. Higuraskh, A. Toriumi, F. Yamaguchi, K. Kawamura, A. Hubler, Correlation Tunnel Device, U. S. Patent No. 5,679,961 (1997) [2] Alfred Hubler, http://server10.how-why.com/blog/
18. Fokus: Digital
2014-01-01
sammenhænge og fra forandrede distributionsformer. Dette betyder ændrede betingelser for både produktion og reception af kunstmusik og lydkunst. Med Digital tager vi udgangspunkt i fire komponisters meget forskellige bud på hvordan teknologien spiller en rolle i arbejdet. Juliana Hodkinson beskriver hvordan...
19. CT perfusion imaging and CT subtraction angiography in the diagnosis of ischemic cerebrovascular disease within 24 hours
管小亭; 于学英; 刘翔; 龙洁; 戴建平
2003-01-01
Objective To evaluate the value of the clinical use of CT perfusion imaging (CTPI) and CT subtraction angiography (CTSA) for diagnosing acute ischemic cerebrovascular disease (AICVD). Methods Twenty-four patients with AICVD onset within 24 hours were examined with regular CT, CTPI, and CTSA. Some cases received CTPI, magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), digital subtraction angiography (DSA) or single photon emission computer tomography (SPECT) during follow-up examinations.Results Of the 24 cases, 11 had negative results from regular CT scans 3-6 hours after onset of stroke in 6 cases, 6-12 hours in 3 cases, and 12-24 hours in 2 cases. Ten of these cases were then confirmed by CTPI as having ischemic lesions, 2 with middle cerebral artery occlusion (MCAO), and 1 case with transient ischemic attack (TIA) with CTPI negative. Of the 24 cases, 13 had positive results from regular CT, 9 were diagnosed with ischemic lesions larger by using CTPI than regular CT, 1 case had MCAO and 1 had internal carotid artery occlusion (ICAO). There were 4 cases with ischemic lesions observed with regular CT having nearly the same range as that of lacunar infarctions using CTPI. Another 4 cases had more than 2 lesion areas. The peak time (PT), mean transit time (MTT) and relative flow (RF) of 24 cases were markedly different. The sides of ischemic lesions compared to each other and the core of the lesion compared to peripheral zones were also altered significantly (P<0.01).Conclusions Combined CTPI with CTSA can detect acute ischemic lesions at early and hyper-early stages and could distinguish between TIA, lacunar infarction and a larger area of infarction. Using semiquantitative blood perfusion analysis status, CTPI with CTSA could define position, area and range of the ischemic lesion and penumbra. These scans can also analyze the brain blood perfusion status. It is important to early diagnose the occlusion of the entire division of the internal
20. cDNA amplification by SMART-PCR and suppression subtractive hybridization (SSH)-PCR.
Hillmann, Andrew; Dunne, Eimear; Kenny, Dermot
2009-01-01
The comparison of two RNA populations that differ from the effects of a single-independent variable, such as a drug treatment or a specific genetic defect, can identify differences in the abundance of specific transcripts that vary in a population-dependent manner. There are a variety of methods for identifying differentially expressed genes, including microarray, SAGE, qRT-PCR, and DDGE. This protocol describes a potentially less sensitive yet relatively easy and cost-effective alternative that does not require prior knowledge of the transcriptomes under investigation and is particularly applicable when minimal levels of starting material, RNA, are available. RNA input can often be a limiting factor when analyzing RNA from, for example, rigorously purified blood cells. This protocol describes the use of SMART-PCR to amplify cDNA from sub-microgram levels of RNA. The amplified cDNA populations under comparison are then subjected to suppression subtractive hybridization (SSH-PCR), a technique that couples subtractive hybridization with suppression PCR to selectively amplify fragments of differentially expressed genes. The final products are cDNA populations enriched for significantly over-represented transcripts in either of the two input RNA preparations. These cDNA populations may then be cloned to make subtracted cDNA libraries and/or used as probes to screen subtracted cDNA, global cDNA, or genomic DNA libraries.
1. COMPARISON OF GEOMETRIC PRECISION OF PLASTIC COMPONENTS MADE BY SUBTRACTIVE AND ADDITIVE METHODS
Paweł Fudali
2013-09-01
Full Text Available The paper presents information on manufacturing processes of plastic components. Basic subtractive and additive methods are described. There were also manufactured elements of fan housing by using this two types of methods. Then, the elements were measured using a touch probe. The obtained results were analyzed, on which a comparison of components’ geometric accuracy was performed.
2. PHOTON-SUBTRACTED (-ADDED) THERMO VACUUM STATE AND THEIR APPLICATION IN JACOBI POLYNOMIALS
DA Cheng; FAN Hong-yi
2015-01-01
We construct photon-subtracted (-added) thermo vacuum state by normalizing them. As their application we derive some new generating function formulas of Jacobi polynomials, which may be applied to study other problems in quantum mechanics. This will also stimulate the research of mathematical physics in the future.
3. Pre-operative sestamibi-technetium subtraction scintigraphy in primary hyperparathyroidism: Experience with 156 consecutive patients
Jones, J. Mark; Russell, Colin F.J.; Ferguson, W. Rodney; Laird, James D
2001-07-01
AIM: The aim of this study was to assess the usefulness of pre-operative sestamibi-technetium subtraction scintigraphy in a large cohort of patients with primary hyperparathyroidism (HPT). MATERIALS AND METHODS: A group of 156 consecutive patients with biochemically proven HPT underwent sestamibi-technetium subtraction scintigraphy before cervical exploration. Images were interpreted and reported prospectively and influenced the extent of surgical exploration. The intraoperative findings were compared retrospectively with the pre-operative scintigram reports in 154 individuals with technically satisfactory scintigrams. RESULTS: Of the 154 patients with satisfactory scintigrams, 122 (78.2%) demonstrated a single focus of activity following subtraction, 31 (19.9%) had negative findings and the remaining scintigram showed four foci of activity. At operation 138 (89.6%) solitary adenomas were removed, 13 patients (8.4%) had multi-gland disease and in three individuals (2.0%) no abnormal parathyroid tissue was found. The pre-operative scintigram accurately localized 91 of 98 (92.9%) solitary tumours weighing > 500 mg but only 18 of 35 (51.4%) adenomas weighing < 500 mg, (P < 0.0001). Overall sensitivity of sestamibi-technetium scintigraphy for localizing single parathyroid adenomas was 83.7%. CONCLUSION: Sestamibi-technetium subtraction scintigraphy will accurately localize a high proportion of solitary parathyroid adenomas but its usefulness is diminished by its inability to consistently identify smaller tumours. Jones, J.M. et al. (2001)
4. Combining Suppression Subtractive Hybridization and Microarrays To Map the Intraspecies Phylogeny of Flavobacterium psychrophilum
Soule, Marilyn; Cain, Kenneth; Lafrentz, Stacey; Douglas R. Call
2005-01-01
Reciprocal subtractive libraries were prepared for two strains of Flavobacterium psychrophilum, one virulent and the other avirulent in a trout challenge model. Unique clones were sequenced and their distribution assessed among 34 strains. The analysis showed that F. psychrophilum is composed of two genetic lineages, possibly reflecting host specificity.
5. Identification of a pheA gene associated with Streptococcus mitis by using suppression subtractive hybridization.
Park, Hee Kuk; Dang, Hien Thanh; Myung, Soon Chul; Kim, Wonyong
2012-04-01
We performed suppression subtractive hybridization to identify genomic differences between Streptococcus mitis and Streptococcus pneumoniae. Based on the pheA gene, a primer set specific to S. mitis detection was found in 18 out of 103 S. mitis-specific clones. Our findings would be useful for discrimination of S. mitis from other closely related cocci in the oral environment.
6. Identification by Suppression Subtractive Hybridization of Frankia Genes Induced under Nitrogen-Fixing Conditions▿ †
Yamaura, Masatoshi; UCHIUMI, Toshiki; Higashi, Shiro; Abe, Mikiko; Kucho, Ken-ichi
2010-01-01
Frankia is an actinobacterium that fixes nitrogen under both symbiotic and free-living conditions. We identified genes upregulated in free-living nitrogen-fixing cells by using suppression subtractive hybridization. They included genes with predicted functions related to nitrogen fixation, as well as with unknown function. Their upregulation was a novel finding in Frankia.
7. Identification of a pheA Gene Associated with Streptococcus mitis by Using Suppression Subtractive Hybridization
Park, Hee Kuk; Dang, Hien Thanh; Myung, Soon Chul; Kim, Wonyong
2012-01-01
We performed suppression subtractive hybridization to identify genomic differences between Streptococcus mitis and Streptococcus pneumoniae. Based on the pheA gene, a primer set specific to S. mitis detection was found in 18 out of 103 S. mitis-specific clones. Our findings would be useful for discrimination of S. mitis from other closely related cocci in the oral environment.
8. Genetic Differences between Two Strains of Xylella fastidiosa Revealed by Suppression Subtractive Hybridization†
Harakava,Ricardo; Gabriel, Dean W.
2003-01-01
Suppression subtractive hybridization was used to rapidly identify 18 gene differences between a citrus variegated chlorosis (CVC) strain and a Pierce's disease of grape (PD) strain of Xylella fastidiosa. The results were validated as being highly representative of actual differences by comparison of the completely sequenced genome of a CVC strain with that of a PD strain.
9. Developing Prospective Teachers' Understanding of Addition and Subtraction with Whole Numbers
Roy, George J.
2014-01-01
This study was situated in a semester-long classroom teaching experiment examining prospective teachers' understanding of number concepts and operations. The purpose of this paper is to describe the learning goals, tasks, and tools used to cultivate prospective teachers' understanding of addition and subtraction with whole numbers.…
10. A new approach of binary addition and subtraction by non-linear material based switching technique
Archan Kumar Das; Partha Partima Das; Sourangshu Mukhopadhyay
2005-02-01
Here, we refer a new proposal of binary addition as well as subtraction in all-optical domain by exploitation of proper non-linear material-based switching technique. In this communication, the authors extend this technique for both adder and subtractor accommodating the spatial input encoding system.
11. Advanced nanopattern formation by a subtractive self-organization process with focused ion beams
Lugstein, A. [Technical University Vienna, Floragasse 7, 1040 Vienna (Austria)]. E-mail: [email protected]; Basner, B. [Technical University Vienna, Floragasse 7, 1040 Vienna (Austria); Brezna, W. [Technical University Vienna, Floragasse 7, 1040 Vienna (Austria); Weil, M. [Technical University Vienna, Floragasse 7, 1040 Vienna (Austria); Golka, S. [Technical University Vienna, Floragasse 7, 1040 Vienna (Austria); Bertagnolli, E. [Technical University Vienna, Floragasse 7, 1040 Vienna (Austria)
2006-01-15
We have studied the evolution of the GaAs, InAs and GaSb surfaces due to FIB exposure. In contrast to conventional bottom up or top down processes the observed nanopattern formation is discussed, based on a subtractive self-organization process relying on material decomposition induced by FIB exposure.
12. [Construction and analysis of subtractive cDNA library associated with multidrug resistance of acute leukemia].
Ji, Lei; Zhang, Wang-Gang; Liu, Jie; Liu, Xin-Ping; Yao, Li-Bo
2004-08-01
The study was aimed to construct subtractive cDNA library associated with multidrug resistance (MDR) of acute leukemia for screening genes related to MDR in leukemia. The improved PCR-based subtractive hybridization was performed to clone differential genes between HL-60/VCR and HL-60 cell line. The mRNA of HL-60/VCR and HL-60 cell line were isolated. Then the mRNA of HL-60/VCR group was reversely transcribed into cDNA by Cap-Finder method, and the mRNA of HL-60 was reversely transcribed into cDNA by ordinary method to be marked by biotin for the hybridization next with HL-60/VCR cDNA. After hybridizing, filtrating through the sephacryl S-400 column, absorbing by the magnetic beads, and amplifying by PCR method, the fragments were cloned by T-A method and the cDNA library was constructed. Then the quality of cDNA library was identified by dot-blotting hybridization method. The results showed that after constriction, the library demonstrated its good quality. There was a high proportion of large fragments in this library. From small amount of samples a large amount of candidate fragments could be screened rapidly at once by dot-blotting hybridization. It is concluded that a differentially-expressed subtractive cDNA library in MDR of leukemia with high quality and larger fragments can be efficiently constructed by improving subtractive hybridization and selective PCR method.
13. Isolation of carrot Argonaute1 from subtractive somatic embryogenesis cDNA library.
Takahata, Kiminori
2008-03-01
Carrot Argonaute1 (C-Ago1) was isolated from a subtractive cDNA library to obtain somatic embryogenesis related genes. C-Ago1 has three conserved domains, which are found in all other Argonautes. C-Ago1 has specific expression during somatic embryogenesis, which indicates that microRNA gene expression controlling system is required for somatic embryogenesis.
14. Dissociation of Subtraction and Multiplication in the Right Parietal Cortex: Evidence from Intraoperative Cortical Electrostimulation
Yu, Xiaodan; Chen, Chuansheng; Pu, Song; Wu, Chenxing; Li, Yongnian; Jiang, Tao; Zhou, Xinlin
2011-01-01
Previous research has consistently shown that the left parietal cortex is critical for numerical processing, but the role of the right parietal lobe has been much less clear. This study used the intraoperative cortical electrical stimulation approach to investigate neural dissociation in the right parietal cortex for subtraction and…
15. Generating Scenarios of Addition and Subtraction: A Study of Japanese University Students
Kinda, Shigehiro
2013-01-01
Students are presented with problems involving three scenario types of addition and subtraction in elementary mathematics: one dynamic ("Change") and two static ("Combine, Compare"). Previous studies have indicated that the dynamic type is easier for school children, whereas the static types are more difficult and comprehended only gradually…
16. Issues relating to the subtraction phase in EOG artefact correction of the EEG.
Croft, Rodney J; Barry, Robert J
2002-06-01
An important method for removing the effect of ocular artefact from the EEG is 'EOG correction'. This method estimates the proportion of ocular artefact that is in the EEG, and removes it by subtraction. To date, EOG correction research has focused on problems relating to the estimation of the correction coefficients. Using both mathematical rationale and empirical data, this paper addresses issues relating to the subtraction phase, such as the magnitude of error that can be expected due to EOG correction. Using ERP methodology, principal component and regression analyses, it is shown that the N1P2 complex propagates forward to the horizontal and radial (but not vertical) electrooculograms (EOG), and it is shown mathematically that this will result in EOG-correction error. Assuming an accurate estimate of ocular contamination of the EEG, maximal subtraction-phase error of the N1P2 complex was found to be a prefrontal attenuation of 15-22%, decreasing to central and occipital enhancements of 3-4% and 13-14%, respectively. The magnitude of this subtraction-phase error is compared to between-subject ERP variability and to error associated with EOG rejection (omitting data contaminated by ocular artefact). It is argued that such EOG correction error is small relative to both artefact rejection procedures and to normal variability found in ERP studies, and that it is less pernicious than artefact rejection procedures.
17. Low-cost addition-subtraction sequences for the final exponentiation computation in pairings
Guzmán-Trampe, Juan E; Cruz-Cortéz, Nareli; Dominguez Perez, Luis
2014-01-01
In this paper, we address the problem of finding low cost addition–subtraction sequences for situations where a doubling step is significantly cheaper than a non-doubling one. One application of this setting appears in the computation of the final exponentiation step of the reduced Tate pairing d...
18. Strategies for Solving Simple Subtractions as Reflected by Children's Verbal Reports.
Svenson, Ola; Hedenborg, Maj-Lene
1980-01-01
Children, 9-11 years old, solved subtraction problems in the form of M-N=..., then gave a verbal report on the thought processes used, analysis of which utilized a model based on analyses of reaction times, and resulted in a more detailed process model. (AN)
19. Heritage Language Learners in Mixed Spanish Classes: Subtractive Practices and Perceptions of High School Spanish Teachers
Randolph, Linwood J., Jr.
2017-01-01
This qualitative study investigated the language ideologies and instructional practices of an entire Spanish language faculty at a high school in a new gateway state for immigration. The study examined additive and subtractive practices of teachers as they strived to teach Spanish to heritage language learners (HLLs) enrolled in mixed…
20. "It is Possible to Die Before Being Born". Negative Integers Subtraction: A Case Study
Gallardo, Aurora
2003-01-01
A Case Study is presented in this article, where there is a contradiction between pre-algebraic language semantic and syntax used to solve word problems through a negative integers subtraction. Appendix includes answer key. (Contains 1 figure.) [For complete proceedings, see ED500859.
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https://aps.arxiv.org/list/quant-ph/pastweek?skip=156&show=10
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# Quantum Physics
## Authors and titles for recent submissions, skipping first 156
[ total of 251 entries: 1-10 | ... | 127-136 | 137-146 | 147-156 | 157-166 | 167-176 | 177-186 | 187-196 | ... | 247-251 ]
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[157]
Title: Modeling and simulating formation of neutral hydrogen molecule in Tavis-Cummings-Hubbard model
Subjects: Quantum Physics (quant-ph)
[158]
Title: The Context Communication Cost of Simulating Quantum Correlations
Authors: Karl Svozil
Comments: 9 pages, 3 figures, 1 table
Subjects: Quantum Physics (quant-ph)
[159]
Title: Quantum annealing with symmetric subspaces
Subjects: Quantum Physics (quant-ph)
[160]
Title: Stabilizer Approximation
Subjects: Quantum Physics (quant-ph); Strongly Correlated Electrons (cond-mat.str-el); Atomic Physics (physics.atom-ph); Chemical Physics (physics.chem-ph)
[161]
Title: Wave function realization of a thermal collision model
Subjects: Quantum Physics (quant-ph)
[162]
Title: Parametric Synthesis of Quantum Circuits for Training Perceptron Neural Networks
Subjects: Quantum Physics (quant-ph); Emerging Technologies (cs.ET)
[163]
Title: Programmable time-multiplexed squeezed light source
Subjects: Quantum Physics (quant-ph); Optics (physics.optics)
[164]
Title: Exactly solvable piecewise analytic double well potential $V_{D}(x)=min[(x+d)^2,(x-d)^2]$ and its dual single well potential $V_{S}(x)=max[(x+d)^2,(x-d)^2]$
Authors: Ryu Sasaki
Comments: LaTeX2e, 16 pages, 6 figures
Subjects: Quantum Physics (quant-ph)
[165]
Title: Interferometry and higher-dimensional phase measurements using directionally unbiased linear optics
Journal-ref: Physical Review A 106, 033706 (2022)
Subjects: Quantum Physics (quant-ph)
[166]
Title: A universal time-dependent control scheme for realizing arbitrary bosonic unitaries
Comments: 7 pages, 4 figures + Supplementary material (4 pages, 1 figure)
Subjects: Quantum Physics (quant-ph)
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Links to: arXiv, form interface, find, quant-ph, new, 2209, contact, help (Access key information)
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https://worldwidescience.org/topicpages/i/inner+cities+sociology.html
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#### Sample records for inner cities sociology
1. Inflation, economic policy, and the inner city
Energy Technology Data Exchange (ETDEWEB)
Curtis, L.A.
1981-07-01
This article describes the greater impact of inflation among the poor and minorities in American inner cities than among other population groups. Surveys show, however, that minorities are even more concerned over unemployment and racial discrimination than over inflation. There are indications that, especially today, crime and potential group disorder are affected by or influence inflation, unemployment, and discrimination in the inner city. With these interrelated factors in mind, present federal economic policy is reviewed, critiqued, and interpreted as basically consistent with Keynesian economic theory. Modifications of and alternatives to present policy are offered that fit both inner-city needs and the concerns of the rest of American society. These policies include targeted private sector neighborhood development and self-help, private sector productivity increases through workplace democracy, private-public sector codetermination of investment, private-public sector job guarantees, and public anti-inflation policy carefully targeted at the basic necessities of energy, food, housing, and health care - which have a disproportionate effect on inflation in the inner city, as well as the overall economy. Coalitions are suggested that could politically implement such policies.
2. 'Schismo-urbanism': cities, natural disaster, and urban sociology.
Science.gov (United States)
Kammerbauer, Mark
2013-07-01
This paper examines a city and a natural disaster, specifically New Orleans, Louisiana, after Hurricane Katrina of August 2005. Recovery here is ongoing and the process of return is incomplete, with long-term dislocation to other cities in the United States, such as Houston, Texas. The question arises as to how planning and stratification influence evacuation and return/dislocation and how they result in a particular practice of adaptation. This interrelated process is conceptually integrated and termed 'schismo-urbanism' and is analysed within a multidimensional theoretical framework to evaluate aspects of urban sociology and natural disasters. Empirical research is based on a quantitative and qualitative mixed-method case study. Data were collected during two rounds of field research in New Orleans and Houston in 2007 and 2009. As a comparative socio-spatial study of affected and receptor communities, it makes a novel theoretical and methodological contribution to research on urban disasters in the context of continuing and rapid social change, and is targeted at disaster researchers, planning theorists and practitioners, and urbanists. © 2013 The Author(s). Journal compilation © Overseas Development Institute, 2013.
3. Securing Failed Inner-City Communities: The Military's Role
National Research Council Canada - National Science Library
Khan, Oral
1997-01-01
This study examines the threat to internal security posed by violent gangs. This threat was found to be particularly acute in inner-city communities that have over time devolved to a status that the author classified as failed communities...
4. Family Planning for Inner-City Adolescent Males: Pilot Study.
Science.gov (United States)
Reis, Janet; And Others
1987-01-01
Describes a pilot family planning program in an inner-city pediatric practice. Male adolescents were more likely to accept contraceptives if the provider first raised the topic of birth control to them. Identified a desire for anonymity/confidentiality and embarrassment or discomfort as the key reasons for not seeking contraceptives. Emphasizes…
5. Waldorf Education in an Inner-City Public School.
Science.gov (United States)
McDermott, Ray; And Others
1996-01-01
Reports on the achievement of the first Waldorf public elementary school in Milwaukee (Wisconsin). Early experience indicates that Waldorf pedagogy, with its emphasis on the natural rhythms of everyday life, is an effective model for predominantly African American children in an inner city. (SLD)
6. Forest School in an Inner City? Making the Impossible Possible
Science.gov (United States)
Elliott, Heather
2015-01-01
The Forest School approach to Early Years education, originally developed in Scandinavia, is influencing learning outside the classroom in England. An inner city primary school in Yorkshire investigated the nature and purpose of Forest Schools in Denmark, through a study visit, prior to developing their own Forest School in the midst of an urban…
7. Drama, Media Advertising, and Inner-City Youth.
Science.gov (United States)
2002-01-01
Describes a reflective practice case study which involved creating and delivering a unit integrating drama, media literacy, and media production with a focus on advertising for a group of students at an alternative inner-city high school. Proposes this strategy may assist others in studies and teaching practice. (PM)
8. Inner City Providence: Implications for Education. Attachment 2.
Science.gov (United States)
Blanchard, Walter J.
This is a collection of raw data and brief descriptions of the neighborhoods which compose the inner city of Providence. It was compiled so that staff, teachers, and the community leaders could think together about the implications of these data for the schools, education, and for the social studies project. Demographic data on the seven…
9. Problems of European inner cities and their residential environments
Czech Academy of Sciences Publication Activity Database
Vaishar, Antonín; Zapletalová, Jana
2003-01-01
Roč. 11, č. 2 (2003), s. 24-35 ISSN 1210-8812 Grant - others:Evropská unie(XE) EVK4-CT-2002-00086 Institutional research plan: CEZ:AV0Z3086906 Keywords : inner city, residential environment, sustainibility, re- urbanization , Brno Subject RIV: DE - Earth Magnetism, Geodesy, Geography
10. Popular Media, Critical Pedagogy, and Inner City Youth
Science.gov (United States)
Leard, Diane Wishart; Lashua, Brett
2006-01-01
In this article, we explored ways youth, traditionally silenced, engaged with popular culture to voice experiences and challenge dominant narratives of public schools and daily lives. We also considered how educators use popular culture as critical pedagogy with inner city youth. Through ethnographic bricolage and case study methods, and drawing…
11. Lines of sociological analysis of times policies in the city
Directory of Open Access Journals (Sweden)
Carmen Belloni
1996-04-01
Full Text Available 1. Innovative elements 1.1. The city Interest in the city as a subject of study: the city is defined as an administrative and government unit, a morphological unit, a unit of identification. Definition of the city as a social entity: the city not only as an administrative and/or planning unit, but also as the result of the needs and behaviours of inhabitants and of city users. Analytical definition of the population: the citizens not as an undifferentiated unit, but as a plurality of actor...
12. Predictors of Airborne Endotoxin Concentrations in Inner City Homes
Science.gov (United States)
Mazique, D; Diette, GB; Breysse, PN; Matsui, EC; McCormack, MC; Curtin-Brosnan, J; Williams, D; Peng, RD; Hansel, NN
2011-01-01
Few studies have assessed in-home factors which contribute to airborne endotoxin concentrations. In 85 inner-city Baltimore homes, we found no significant correlation between settled dust and airborne endotoxin concentrations. Certain household activities and characteristics, including frequency of dusting, air conditioner use and type of flooring, explained 36–42% of the variability of airborne concentrations. Measurements of both airborne and settled dust endotoxin concentrations may be needed to fully characterize domestic exposure in epidemiologic investigations. PMID:21429483
13. Asthma in inner city children: recent insights: United States.
Science.gov (United States)
Dutmer, Cullen M; Kim, Haejin; Searing, Daniel A; Zoratti, Edward M; Liu, Andrew H
2018-04-01
Children living in US inner cities experience disparate burdens of asthma, especially in severity, impairment, exacerbations, and morbidity. Investigations seeking to better understand the factors and mechanisms underlying asthma prevalence, severity, and exacerbation in children living in these communities can lead to interventions that can narrow asthma disparities and potentially benefit all children with asthma. This update will focus on recent (i.e. late 2016-2017) advances in the understanding of asthma in US inner city children. Studies published in the past year expand understanding of asthma prevalence, severity, exacerbation, and the outcomes of guidelines-based management of these at-risk children, including: asthma phenotypes in US inner city children that are severe and difficult-to-control; key environmental determinants and mechanisms underlying asthma severity and exacerbations (e.g. allergy-mediated exacerbation susceptibility to rhinovirus); the importance of schools as a place for provocative exposures (e.g. mouse allergen, nitrogen dioxide) as well as a place where asthma care and outcomes can be improved; and the development and validation of clinically useful indices for gauging asthma severity and predicting exacerbations. These recent studies provide a trove of actionable findings that can improve asthma care and outcomes for these at-risk children.
14. The inner-city Skater Facility - playground or control mechanism?
DEFF Research Database (Denmark)
Gravesen, David Thore
2016-01-01
special Social services, School and Police unit), that observe, mingle and socialize at the facility. The social workers affiliated with the SSP understand and define their role in contradiction to the official agenda. The social workers seek to pull the young people off the street and get them to enroll......The inner-city Skater Facility - playground or control mechanism? In 2013, the municipality in Horsens, a medium-sized provincial town in Denmark, bestowed the city's children and young people a skater facility at the city's central squares. Officially, the municipality donated the facility to give...... local children and young people an opportunity to use their leisure time stimulating their bodies, having a great time with friends and other urban dwellers. The gift is accompanied by a number of (more or less camouflaged) crime prevention- and social education agendas, carried out by the SSP (a...
15. Inner-City Energy and Environmental Education Consortium
Energy Technology Data Exchange (ETDEWEB)
1993-06-11
The numbers of individuals with adequate education and training to participate effectively in the highly technical aspects of environmental site cleanup are insufficient to meet the increasing demands of industry and government. Young people are particularly sensitive to these issues and want to become better equipped to solve the problems which will confront them during their lives. Educational institutions, on the other hand, have been slow in offering courses and curricula which will allow students to fulfill these interests. This has been in part due to the lack of federal funding to support new academic programs. This Consortium has been organized to initiate focused educational effort to reach inner-city youth with interesting and useful energy and environmental programs which can lead to well-paying and satisfying careers. Successful Consortium programs can be replicated in other parts of the nation. This report describes a pilot program in Washington, DC, Philadelphia, and Baltimore with the goal to attract and retain inner-city youth to pursue careers in energy-related scientific and technical areas, environmental restoration, and waste management.
16. Socioeconomic impact of urban redevelopment in inner city of Ningbo
Institute of Scientific and Technical Information of China (English)
BACHOUR Bachir; DONG Wei
2006-01-01
Since market-oriented economy reform, China has experienced significant changes in urban landscapes and the internal structure of cities. Housing marketization provides an opportunity for households to choose their residences. Hwever, not all households benefit equally from residential relocation. Residential relocation in urban China has relatively strong association with the household's position within the spectrum from state redistribution to market reward than with life cycles and consequent adjustment of housing demand, which are the primary reasons for residential mobility in a mature market. In this research we focused on social aspects, mainly relating to the impact of urban redevelopment in inner city of Ningbo and the resultant potential housing problem. This research is based on a questionnaire survey that was conducted in three neighborhoods redeveloped at different time periods in the past fifteen years. The findings suggest that new strategy of redevelopment of the integrated environment of the old city while still improving the living condition for its residents can be heard due to the efforts of many people at various positions. Yet, many things need to be done to change people's ideas: information and education through newspapers,academic discussions through academic journals, conferences, and reports to decision makers.
17. Competence skills help deter smoking among inner city adolescents.
Science.gov (United States)
Epstein, J A; Griffin, K W; Botvin, G J
2000-03-01
To test whether higher levels of general competence are linked to more frequent use of refusal assertiveness that is in turn related to less subsequent smoking among inner city adolescents. Longitudinal study conducted during three year middle school or junior high school period. A sample of 1459 students attending 22 middle (ages 11-14 years) and junior high (ages 12-15 years) schools in New York City participated. Students completed surveys at baseline, one year follow up, and two year follow up. The students self reported smoking, decision making skills, personal efficacy, and refusal assertiveness. Teams of three to five data collectors administered the questionnaire following a standardised protocol. These data were collected in school during a regular 40 minute class period. Based on the tested structural equation model, decision making and personal efficacy (that is, general competence) predicted higher refusal assertiveness and this greater assertiveness predicted less smoking at the two year follow up. The tested model had a good fit and was parsimonious and consistent with theory. Adolescent smoking prevention programmes often teach refusal skills in order to help youth resist peer pressure to smoke. The present findings suggest that teaching general competence skills as well may help to reduce smoking because youth with better personal efficacy and decision making skills are better able to implement smoking refusal strategies.
18. Cultural Relevance and Working with Inner City Youth Populations to Achieve Civic Engagement
Science.gov (United States)
Ward, Shakoor; Webster, Nicole
2011-01-01
This article helps Extension professionals consider the cultural relevant needs of inner city residents in hopes of achieving ongoing civic engagement and appropriate program activities in these communities. Having a deep understanding of how the various dimensions of marginalized community life among inner city populations affect participation in…
19. Elaborating on ubuntu in a Johannesburg inner-city church
Directory of Open Access Journals (Sweden)
Elina Hankela
2015-01-01
Full Text Available The article was originally delivered as the speech of the winner of the 2014 Donner Institute Prize for Outstanding Research into Religion, and deals with some core findings of the research that won the prize, namely, the doctoral thesis Challenging Ubuntu: Open Doors and Exclusionary Boundaries at the Central Methodist Mission in Johannesburg. The author approaches the meanings of ubuntu (Nguni: humanity/humanness in the context of a Methodist church that sheltered thousands of African migrants in its premises in the inner city of Johannesburg. Using ethnographic research methods, she analyses both the inclusionary message of humanity preached at the church and the exclusionary boundaries between the people who lived in the church and the local congregation that worshipped there. Based on the social dynamics of the church community, the author suggests the rules of reciprocity and survival as some of the socio-moral patterns that set the boundaries to the actualisation of the moral ideal of ubuntu in this context. Overall, the case of this particular church speaks to a broader discussion of the meaning of and limits to being human in one world.
20. The Moral Economy of Violence in the US Inner City
Science.gov (United States)
Karandinos, George; Hart, Laurie Kain; Castrillo, Fernando Montero; Bourgois, Philippe
2014-01-01
In an 8-week period, there were 16 shootings with three fatalities, three stabbings, and 14 additional “aggravated assaults” in the four square blocks surrounding our field site in the Puerto Rican corner of North Philadelphia. In the aftermath of the shoot-outs, the drug sellers operating on our block were forced to close down their operations by several mothers who repeatedly called the police. Drawing on the concept of moral economy (Thompson, Scott, Taussig), Mauss’s interpretation of gift exchange, and a political economy critique of hypercarceralization in the United States, we understand the high levels of US inner-city violence as operating within a moral logic framed by economic scarcity and hostile state relations. Residents seek security, self-respect, and profit in social networks that compel them to participate in solidary exchanges of assistive violence dynamized by kinship and gender obligations. A hierarchical, extractive drug economy fills the void left by deindustrialization, resulting in a dynamic of embodied primitive accumulation at the expense of addicted customers and chronically incarcerated just-in-time street sellers at high risk of assault. Nevertheless, the mobilization of violence organizing the illegal drug economy also follows ethical norms and obligations that are recognized as legitimate by many local residents. PMID:25067849
1. IMAGINE-ing interprofessional education: program evaluation of a novel inner city health educational experience
Directory of Open Access Journals (Sweden)
Tina Hu
2017-02-01
Conclusion: Interprofessional inner city health educational programs are beneficial for students to learn about poverty intervention and resources, and may represent a strategy to address a gap in the healthcare professional curriculum.
2. Neighborhood poverty, urban residence, race/ethnicity, and asthma: Rethinking the inner-city asthma epidemic.
Science.gov (United States)
Keet, Corinne A; McCormack, Meredith C; Pollack, Craig E; Peng, Roger D; McGowan, Emily; Matsui, Elizabeth C
2015-03-01
3. Socialism. Grade Ten, Unit Two, 10.2. Comprehensive Social Studies Curriculum for the Inner City.
Science.gov (United States)
Malone, Helen
The socialism unit of the tenth grade level of the FICSS series (Focus on Inner City Social Studies -- see SO 008 271) explores a selected history of socialist thought and the theoretical model of socialism. Three case studies of socialism are explored: Great Britain, Sweden, and Israel. The case studies are designed to answer questions concerning…
4. Family Life Education for Young Inner-City Teens: Identifying Needs.
Science.gov (United States)
Herz, Elicia J.; Reis, Janet S.
1987-01-01
Sexual decision making, perceptions of responsibility for birth control and pregnancy, and knowledge of contraception and the consequences of teenage pregnancy were assessed among 251 high-risk seventh- and eighth-grade Black, inner-city adolescents to determine these young peoples' need for information. (Author/LMO)
5. An Inner-City School Mentor: A Narrative Inquiry of the Life Experiences of "Daddy"
Science.gov (United States)
Li, Xin; Lal, Dhyan
2006-01-01
A two-year ethnographic observation of an inner-city high school in Los Angeles, USA, indicated that the principal, who was extremely dedicated to at-risk students and possessed a unique style of mentoring, played a major role in students academic achievement. We--the principal and the researcher who observed the school--inquired about the…
6. Predictors of Future Expectations of Inner-City Children: A 9-Month Prospective Study.
Science.gov (United States)
Dubow, Eric F.; Arnett, Mitzi; Smith, Katherine; Ippolito, Maria F.
2001-01-01
Assessed contributions of internal resources, supportive family and peer relations, peer negative influences, and behavioral adjustment to positive expectations for the future for inner-city school children. Found that higher levels of positive expectation related to lower levels of problem behavior and to higher levels of school involvement,…
7. Searching for cures: Inner-city and rural patients' awareness and perceptions of cancer clinical trials
Directory of Open Access Journals (Sweden)
Mugur Geana
2017-03-01
Full Text Available Fewer than 5% of cancer patients participate in clinical trials, making it challenging to test new therapies or interventions for cancer. Even within that small number, patients living in inner-city and rural areas are underrepresented in clinical trials. This study explores cancer patients' awareness and perceptions of cancer clinical trials, as well as their perceptions of patient-provider interactions related to discussing cancer clinical trials in order to improve accrual in cancer clinical trials. Interviews with 66 former and current in inner-city and rural cancer patients revealed a lack of awareness and understanding about clinical trials, as well as misconceptions about what clinical trials entail. Findings also revealed that commercials and television shows play a prominent role in forming inner-city and rural patients' attitudes and/or misconceptions about clinical trials. However, rural patients were more likely to hold unfavorable views about clinical trials than inner-city patients. Patient-provider discussions emerged as being crucial for increasing awareness of clinical trials among patients and recruiting them to trials. Findings from this study will inform communication strategies to enhance recruitment to cancer clinical trials by increasing awareness and countering misconceptions about clinical trials.
8. Teachers' Perceptions of Effective Classroom Management within an Inner-City Middle School.
Science.gov (United States)
Turner, Catana L.
This study was undertaken to obtain descriptive information about teachers' perceptions of effective classroom management within an inner-city middle school. Thirteen teachers in one such school in Tennessee were interviewed about their classroom management behaviors. Teachers appeared to have an elaborate system of beliefs related to the themes…
9. An Afrocentric Approach to Group Social Skills Training with Inner-City African American Adolescents.
Science.gov (United States)
Banks, Reginald; Hogue, Aaron; Liddle, Howard; Timberlake, Terri
1996-01-01
Compared the effectiveness for inner-city African-American youth (n=64) of two social-skills training curricula focusing on problem solving, anger management, and conflict resolution. Both the Afrocentric curriculum and the one that was merely culturally relevant yielded similar decreases in anger and increases in assertiveness and self-control.…
10. Teaching Practices and Strategies to Involve Inner-City Parents at Home and in the School
Science.gov (United States)
Lewis, Leontye; Kim, Yanghee A.; Bey, Juanita Ashby
2011-01-01
Few studies have observed what teachers actually do in the classroom to encourage parental involvement in their children's education. Over the school year, the various teaching practices and strategies of two teachers in an inner-city elementary school that has had public recognition in its efforts to involve parents were gathered through…
11. Public response to the urban forest in inner-city business districts
Science.gov (United States)
Kathleen L. Wolf
2003-01-01
Revitalization programs are under way in many inner-city business districts. An urban forestry program can be an important element in creating an appealing consumer environment, yet it may not be considered a priority given that there are often many physical improvements needs. This research evaluated the role of trees in consumer/...
12. Resource Loss and Naturalistic Reduction of PTSD among Inner-City Women
Science.gov (United States)
Walter, Kristen H.; Hobfoll, Stevan E.
2009-01-01
Halting the process of psychosocial and material resource loss has been theorized as being associated with the reduction of posttraumatic stress disorder (PTSD). This study examines how the limiting of resource loss is related to alleviation of PTSD symptoms among 102 inner-city women, who originally met diagnostic criteria for PTSD after…
13. Characteristics of Health Educators Desired by Inner-City Health Clinic Patients: A Case Study
Science.gov (United States)
Price, James; Sidani, Jaime
2007-01-01
A group (n = 170) of inner-city, predominantly African American, health clinic patients were asked to identify the characteristics they desired in a new clinic health educator. A plurality (44%) of the patients perceived a bachelor's degree would be a sufficient level of education. The vast majority of patients claimed the sex of the health…
14. ACUTE RESPIRATORY HEALTH EFFECTS OF AIR POLLUTION ON ASTHMATIC CHILDREN IN US INNER CITIES
Science.gov (United States)
BACKGROUND: Children with asthma in inner-city communities may be particularly vulnerable to adverse effects of air pollution because of their airways disease and exposure to relatively high levels of motor vehicle emissions. OBJECTIVE: To investigate the association between fluc...
15. Recent Suicidal Ideation among Patients in an Inner City Emergency Department
Science.gov (United States)
Ilgen, Mark A.; Walton, Maureen A.; Cunningham, Rebecca M.; Barry, Kristen L.; Chermack, Steve T.; De Chavez, Peter; Blow, Frederic C.
2009-01-01
The rates and associated features of suicidal ideation among 5,641 patients seeking routine, nonsuicide related care in an inner-city emergency department were examined. Approximately 8% of patients seeking routine care in the emergency department reported some form of suicidal ideation within the past 2 weeks. Suicidal ideation was common in…
16. Physical Education and Sport Programs at an Inner City School: Exploring Possibilities for Positive Youth Development
Science.gov (United States)
Holt, Nicholas L.; Sehn, Zoe L.; Spence, John C.; Newton, Amanda S.; Ball, Geoff D. C.
2012-01-01
Background: School-based recreational opportunities for youth from low-income inner-city neighbourhoods are often lacking. School programs represent an ideal location for promoting youth development in low-income areas because they can provide safe, supervised, and structured activities. Such activities should include not only physical education…
17. Endotypes of difficult-to-control asthma in inner-city African American children.
Directory of Open Access Journals (Sweden)
K R Brown
Full Text Available African Americans have higher rates of asthma prevalence, morbidity, and mortality in comparison with other racial groups. We sought to characterize endotypes of childhood asthma severity in African American patients in an inner-city pediatric asthma population. Baseline blood neutrophils, blood eosinophils, and 38 serum cytokine levels were measured in a sample of 235 asthmatic children (6-17 years enrolled in the NIAID (National Institute of Allergy and Infectious Diseases-sponsored Asthma Phenotypes in the Inner City (APIC study (ICAC (Inner City Asthma Consortium-19. Cytokines were quantified using a MILLIPLEX panel and analyzed on a Luminex analyzer. Patients were classified as Easy-to-Control or Difficult-to-Control based on the required dose of controller medications over one year of prospective management. A multivariate variable selection procedure was used to select cytokines associated with Difficult-to-Control versus Easy-to-Control asthma, adjusting for age, sex, blood eosinophils, and blood neutrophils. In inner-city African American children, 12 cytokines were significant predictors of Difficult-to-Control asthma (n = 235. CXCL-1, IL-5, IL-8, and IL-17A were positively associated with Difficult-to-Control asthma, while IL-4 and IL-13 were positively associated with Easy-to-Control asthma. Using likelihood ratio testing, it was observed that in addition to blood eosinophils and neutrophils, serum cytokines improved the fit of the model. In an inner-city pediatric population, serum cytokines significantly contributed to the definition of Difficult-to-Control asthma endotypes in African American children. Mixed responses characterized by TH2 (IL-5 and TH17-associated cytokines were associated with Difficult-to-Control asthma. Collectively, these data may contribute to risk stratification of Difficult-to-Control asthma in the African American population.
18. Pollution: Problems and Solutions. Grade Nine, Unit One, 9.1 Comprehensive Social Studies Curriculum for the Inner City.
Science.gov (United States)
Jamison, Sandra; Campbell, Bruce
The ninth grade unit of the FICSS series (Focus on Inner City Social Studies -- see SO 008 271) studies the economic and political realities of the inner city. This document, the first unit of the 9th grade section, deals with the ecological crises involving pollution and its causes. Specific problems include air pollution, pesticides, herbicides,…
19. Precarious housing in the Salvokop neighbourhood: A challenge to churches in the inner City of Tshwane
Directory of Open Access Journals (Sweden)
Ezekiel Ntakirutimana
2017-11-01
Full Text Available This article describes the daunting challenge of precarious housing in Salvokop located in the southern part of inner City of Tshwane, Gauteng Province. Insecure tenure, unmaintained dwellings, overcrowding, mushrooming of backyard shacks and the rise of the informal settlement, all that led to deep levels of vulnerability and neighbourhood deterioration. Current conditions show that life in that neighbourhood is fraught as substandard housing degenerated into slum and squalor. This concern emerged among other salient pressing issues of poverty and vulnerability from the World Café and Focus Groups with the inner city churches including those from Salvokop. The article set out to describe precarious housing, unpleasant living conditions owing to the fact that human beings stay in unsuitable dwellings while the environment deteriorates. Taking into account their circumstances, the article’s aim was to recapture the extent to which the residents suffer as a result of living in dwellings unfit for human habitation, rethinking an alternative model to respond. A theological agenda for future ecclesiological engagement was discerned forthwith recommendations. The article makes a contribution towards the theology of the city in that it stimulates church practices and housing of poor people in Tshwane. It does so by engaging in a unique way grassroots knowledge from the different inner city congregations. This process used the platform of surveys, World Café style gatherings and Focus Groups. In conversation with the primary source, this article also contributed with original data generated with the Salvokop residents whose stories helped to expend on horizons of housing, which is acknowledged. All the inner city church contributors of the realisation of the study objectives are also recognised.
20. New drugs on the street: changing inner city patterns of illicit consumption
National Research Council Canada - National Science Library
Singer, Merrill
2005-01-01
.... 16, No. 1/2 2000. The journal is renumbered to start as Vol. 1, No. 1 2002. New Drugs on the Street: Changing Inner City Patterns of Illicit Consumption, edited by Merrill Singer, PhD (Vol. 4, No. 2, 2005). "ESSENTIAL READING for anyone in the drug use area who wants to be brought up-to-date on the current state of the field. This edited ...
1. Strategic planning and marketing research for older, inner-city health care facilities: a case study.
Science.gov (United States)
Wood, V R; Robertson, K R
1992-01-01
Numerous health care facilities, located in downtown metropolitan areas, now find themselves surrounded by a decaying inner-city environment. Consumers may perceive these facilities as "old," and catering to an "urban poor" consumer. These same consumers may, therefore, prefer to patronize more modern facilities located in suburban areas. This paper presents a case study of such a health care facility and how strategic planning and marketing research were conducted in order to identify market opportunities and new strategic directions.
2. Autonomy and Relatedness in Inner-City Families of Substance Abusing Adolescents
OpenAIRE
Samuolis, Jessica; Hogue, Aaron; Dauber, Sarah; Liddle, Howard A.
2006-01-01
This study examined parent-adolescent autonomous-relatedness functioning in inner-city, ethnic minority families of adolescents exhibiting drug abuse and related problem behaviors. Seventy-four parent-adolescent dyads completed a structured interaction task prior to the start of treatment that was coded using an established autonomous-relatedness measure. Adolescent drug use, externalizing, and internalizing behaviors were assessed. Parents and adolescents completed assessment instruments mea...
3. Collaborating with congregations: opportunities for financial services in the inner city.
Science.gov (United States)
Fondation, L; Tufano, P; Walker, P
1999-01-01
In all economies, financial systems perform a basic set of functions, which include the need to pool resources, to save and borrow, to make payments, and to collect information. And yet, in rich and poor communities, the ways in which those needs are met differ greatly. In part, this is because traditional financial service firms have found it too expensive to serve poor neighborhoods. But it is possible to work with less traditional institutions to meet those needs. According to the authors, inner cities face two core impediments to financial services: lack of economies of scale and lack of good information. An inner-city investor with $500, for instance, does not warrant much attention from financial service firms. But 20,000 parishioners investing$500 apiece can collectively wield $10 million. By partnering with strong social organizations such as churches, financial institutions can benefit both themselves and investors. A lack of good information concerning credit histories--a common problem in poor communities--also makes low-income customers much less appealing to financial institutions. Churches can help close such information gaps by vouching for parishioners' reliability. There are certainly problems that come with mixing business and religion, as the authors concede. Ethical issues, trust issues, and issues of experience all come to mind. But understanding that functions need to dictate the structure of the financial service sector may be the first step toward achieving inner-city prosperity. 4. Understanding sex partner selection from the perspective of inner-city black adolescents. Science.gov (United States) Andrinopoulos, Katherine; Kerrigan, Deanna; Ellen, Jonathan M 2006-09-01 Black adolescents in inner-city settings are at increased risk for HIV and other STDs. Sex partner characteristics, as well as individual behavior, influence individuals' STD risk, yet little is known about the process of sex partner selection for adolescents in this setting. Semistructured in-depth interviews were conducted during the summer and fall of 2002 with 50 inner-city black adolescents (26 females and 24 males) who had been purposively recruited from an STD clinic. Content analysis was used to study interview texts. Young women desire a monogamous romantic partner, rather than a casual sex partner; however, to fulfill their desire for emotional intimacy, they often accept a relationship with a nonmonogamous partner. Young men seek both physical and emotional benefits from being in a relationship; having a partner helps them to feel wanted, and they gain social status among their peers when they have multiple partners. For men, these benefits may help compensate for an inability to obtain jobs that would improve their financial and, as a result, social status. Both women and men assess partners' STD risk on the basis of appearance. HIV and other STD prevention initiatives must go beyond the scope of traditional messages aimed at behavior change and address the need for social support and socioeconomic opportunities among at-risk, inner-city adolescents. 5. Inner-City Energy and Environmental Education Consortium: Inventory of existing programs. Appendix 13.5 Energy Technology Data Exchange (ETDEWEB) 1992-08-21 This is the first effort to prepare an inventory of existing educational programs, focused primarily on inner-city youth, in operation in Washington, DC, Baltimore, and Philadelphia. The purpose of the inventory is to identify existing programs which could be augmented, adapted, or otherwise strengthened to help fulfil the mission of the Department of Energy-sponsored Inner-City Energy and Environmental Education Consortium, the mission of which is to recruit and retain inner-city youth to pursue careers in energy-related scientific and technical areas and in environmental restoration and waste management. The Consortium does not want to reinvent the wheel and all of its members need to learn what others are doing. Each of the 30 participating academic institutions was invited to submit as many program descriptions as they wished. Due to the summer holidays, or because they did not believe than they were carrying out programs relevant to the mission of the Consortium, some institutions did not submit any program descriptions. In addition, several industries, governmental agencies, and not-for-profit institutions were invited to submit program descriptions. 6. THE SOCIOLOGICAL PORTRAIT OF PROVINCIAL UNIVERSITY ENTRANTS ON THE EXAMPLE OF UST-ILIMSK CITY Directory of Open Access Journals (Sweden) Filipp Rozanov 2012-01-01 Full Text Available The article presents the results of sociological study carried out to obtain a general model of ideas, expectations and preferences of provincial students in their attitude to higher education. The received results are presented in the form of diagrams. Provides a general interpretation of the data and on their basis are proposed recommendations for development marketing strategy and campaign to attract university entrants to the provincial university. 7. The Future of Inner City High Schools: The Public-Private Contribution. Proceedings of Conference "The Future of Inner City High Schools: The Public-Private Contribution" (Boston, Massachusetts, June 21-22, 1984). Science.gov (United States) Harvard Univ., Cambridge, MA. Kennedy School of Government. This document summarizes the proceedings of a conference of urban leaders on public-private collaborative efforts to address the problems of inner-city high schools. Findings presented and opinions expressed at sessions on the following topics are outlined: (1) education funds; (2) city-wide umbrella organizations; (3) goal setting--tying jobs and… 8. Blood Lead Levels in Children and Environmental Lead Contamination in Miami Inner City, Florida Directory of Open Access Journals (Sweden) Theophile Niyonsenga 2006-09-01 Full Text Available Studies have shown that the environmental conditions of the home are important predictors of health, especially in low-income communities. Understanding the relationship between the environment and health is crucial in the management of certain diseases. One health outcome related to the home environment among urban, minority, and low-income children is childhood lead poisoning. The most common sources of lead exposure for children are lead paint in older, dilapidated housing and contaminated dust and soil produced by accumulated residue of leaded gasoline. Blood lead levels (BLL as low as 10 μg/dL in children are associated with impaired cognitive function, behavior difficulties, and reduced intelligence. Recently, it is suggested that the standard for intervention be lowered to BLL of 5 μg /dl. The objectives of our report were to assess the prevalence of lead poisoning among children under six years of age and to quantify and test the correlations between BLL in children and lead exposure levels in their environment. This cross-sectional analysis was restricted to 75 children under six years of age who lived in 6 zip code areas of inner city Miami. These locations exhibited unacceptably high levels of lead dust and soil in areas where children live and play. Using the 5 μg/dL as the cutoff point, the prevalence of lead poisoning among the study sample was 13.33%. The study revealed that lead levels in floor dust and window sill samples were positively and significantly correlated with BLL among children (p < 0.05. However, the correlations between BLL and the soil, air, and water samples were not significant. Based on this pilot study, a more comprehensive environmental study in surrounding inner city areas is warranted. Parental education on proper housecleaning techniques may also benefit those living in the high lead-exposed communities of inner city Miami. 9. Role of general and specific competence skills in protecting inner-city adolescents from alcohol use. Science.gov (United States) Epstein, J A; Griffin, K W; Botvin, G J 2000-05-01 The purpose of this longitudinal investigation was to test whether higher levels of general competence are linked to greater refusal assertiveness that is, in turn, related to less subsequent alcohol use among inner-city adolescents. A large sample of students attending 22 middle and junior high schools in New York City participated. Students completed surveys at baseline, at 1-year follow-up and at 2-year follow-up (N = 1,459; 54% female). The students self-reported alcohol use. decision-making skills, self-efficacy and refusal assertiveness. Teams of three to five data collectors administered the questionnaire following a standardized protocol. The data were collected in school during a regular 40-minute class period. According to the tested structural equation model, Decision Making (beta = .07, p Assertiveness and this greater assertiveness predicted less drinking at the 2-year follow-up (beta = -.21, p assertiveness within adolescent alcohol prevention programs. 10. For a historical-sociological approach to the city of Haifa Directory of Open Access Journals (Sweden) Roberto Cipriani 2017-12-01 Full Text Available The city of Haifa, in the northern part of Israel, has been the theatre of harsh clashes between Jews and Muslims for many years. Haifa was heavy involved in the Great Arab Revolt of 1936-1939 and during the 1948 the Palestinian population, about 80.000 people, was evacuated by the Jewish militias. After the establishment of the State of Israel, several terror attacks took place in the city. Today, several religious groups live in Haifa, with non easy relations. Nevertheless, each year the city celebrates the Holyday of Holydays, an interfaith festival. The city presents significant traits that may help us test Tönnies’s idea of a dichotomy between community (Gemeinschaft and society (Gesellschaft. In different moments of city life, we find features typical of community and, in certain others, characteristics typical of society. 11. The socio-economic and environmental impact of school commuting : a case study of the Johannesburg Inner City OpenAIRE 2014-01-01 M.Sc. (Environmental Management) This study explores the school-commuting phenomenon that occurs across the city of Johannesburg, with specific reference to inner city private schools. It was hypothesized that the school commute, much of which has its origins in spatial apartheid, is financially and socially unsustainable. As spatial apartheid continues to dominate the urban landscape in Johannesburg, it is posited that overall, the school commute hinders the City of Johannesburg’s progres... 12. Reassessment of Omalizumab-Dosing Strategies and Pharmacodynamics in Inner-City Children and Adolescents Science.gov (United States) Sorkness, Christine A.; Wildfire, Jeremy J.; Calatroni, Agustin; Mitchell, Herman E.; Busse, William W.; O’Connor, George T.; Pongracic, Jacqueline A.; Ross, Kristie; Gill, Michelle A.; Kattan, Meyer; Morgan, Wayne J.; Teach, Stephen J.; Gergen, Peter J.; Liu, Andrew H.; Szefler, Stanley J. 2014-01-01 BACKGROUND Treatment regimens for omalizumab are guided by a dosing table that is based on total serum IgE and body weight. Limited data exist about onset and offset of omalizumab efficacy in children and adolescents or subgroups that most benefit from treatment. OBJECTIVES Post hoc analyses were conducted to (1) examine patient characteristics of those eligible and ineligible for omalizumab, (2) describe onset of effect after initiation of omalizumab and offset of treatment effect after stopping therapy, and (3) determine whether the efficacy differs by age, asthma severity, dosing regimen, and prespecified biomarkers. METHODS Inner-city children and adolescents with persistent allergic asthma were enrolled in the Inner-City Anti-IgE Therapy for Asthma trial that compared omalizumab with placebo added to guidelines-based therapy for 60 weeks. RESULTS Two hundred ninety-three of 889 participants (33%) clinically suitable for omalizumab were ineligible for dosing according to a modified dosing table specifying IgE level and body weight criteria. Baseline symptoms were comparable among those eligible and ineligible to receive omalizumab, but other characteristics (rate of health care utilization and skin test results) differed. The time of onset of omalizumab effect was omalizumab because of asthma severity status may be ineligible due to IgE >1300 IU/mL. Omalizumab reduced asthma symptoms and exacerbations rapidly; features associated with efficacy can be identified to guide patient selection. PMID:24565455 13. Prevalence of asthma and asthma-like symptoms in inner-city schoolchildren. Science.gov (United States) Mvula, Mosanda; Larzelere, Michele; Kraus, Marjorie; Moisiewicz, Kathleen; Morgan, Connie; Pierce, Stephanie; Post, Robert; Nash, Theresa; Moore, Cleveland 2005-02-01 This study investigates the prevalence of asthma and asthma-related symptoms in New Orleans inner-city schoolchildren. A cross-sectional survey of 1535 elementary, middle, and high school children (aged 5-18) was conducted by using the International Study of Asthma and Allergies in Childhood (ISAAC) written questionnaire. Lifetime prevalence of wheezing was 39.4%, and lifetime prevalence of asthma was 24.4%. Wheezing during the previous 12 months was reported by 25.7% of the sample. Twenty-one percent of respondents reported having one or more attacks of wheezing per year, with 5.6% reporting four or more attacks per year. Many participants reported sleep disturbance (15.4%), with 6.2% reporting sleep disturbance more than once a week. The 12-month rate of speech limitation due to asthma exacerbation was 6.6%. Exercise-induced asthma was reported by 16.9% of the students, and nocturnal cough (not associated with cold) was reported by 27.3%. Overall, boys reported higher rates of symptoms than girls, and younger children (aged 6-7) reported greater symptoms than older children (aged 13-14). These findings show that prevalence of asthma in this population is elevated, and the ISAAC written questionnaire successfully identified inner-city children at risk for asthma in New Orleans. 14. A Social Marketing Intervention to Prevent Drowning Among Inner-City Youth. Science.gov (United States) Glassman, Tavis J; Castor, Tom; Karmakar, Monita; Blavos, Alexis; Dagenhard, Paige; Domigan, Julianne; Sweeney, Erin; Diehr, Aaron; Kucharewski, Ruthie 2018-03-01 Water-related injuries and fatalities pose serious public health issues, especially to African American youth, a demographic group that drowns at disproportionately high rates. The purpose of this study was to determine if a social marketing intervention targeting the parents and guardians of inner-city youth (U.S. Midwest) could positively influence their perceptions concerning water safety. Researchers employed a quasi-experimental design using matched pairs to evaluate the intervention. Participants consisted of parents who enrolled their children in a six-session survival-swimming course. Guided by the Health Belief Model, the researchers disseminated six prevention messages using six different channels (brochure, e-mail, SMS text message, postcard, Facebook, and window cling). The findings from a two-way analysis of covariance revealed that treatment group participants' knowledge and perceptions of water-related threat all changed favorably. Additionally, all participants planned to reenroll their children in swim lessons. A social marketing campaign using the Health Belief Model improved inner-city parents' knowledge regarding water safety and enhanced their self-efficacy. This study provides practitioners with feasible strategies (prevention messages) to supplement swim lessons, with the ultimate goal of preventing drowning among at-risk youth. 15. SOCIAL PORTRAIT OF RURAL TEACHERS: THE RESULTS OF A COMPARATIVE SOCIOLOGICAL STUDY COUNTRY AND CITY TEACHERS Directory of Open Access Journals (Sweden) Lyudmila Alexandrovna Amirova 2017-11-01 Full Text Available The article presents the results of application of the comparative sociological study of rural and urban schools. The characteristic of a social portrait of the rural teacher. The basic social problems, an assessment of social well-being of rural and urban teachers. Purpose. The authors aimed to identify specific problems of the rural school for making sound management decisions in the field of social educational policy. Methodology. A comparative type of applied sociological research is realized by applying such methodological approaches as structural and functional analysis and its variety – typological analysis [2; 3; 5]. Results. In summary, the social portrait of a rural educator is characterized by the following social characteristics. He lives mostly in his own house. One member of his family has, mainly, 12-18 or more square meters of living space. Entrepreneurship and tutoring are poorly distributed in rural areas. In comparison with urban teachers, rural teachers are more oriented to vocational training, rather than to the formation of spiritual and intellectual culture of students. This is the practicality of the rural educator. Employment in the subsidiary farm is also the reason for the greater practicality of the rural teacher and his relatively low spiritual activity. In rural educational institutions the level of collectivism is higher, but the desire for individual achievements is lower. Practical implications. The management of social processes at the level of a rural school can be implemented in the form of social planning, drawing up of social programs, social projects aimed at solving social problems of a rural teacher and optimizing the development of a rural school. 16. An intervention to reduce residential insecticide exposure during pregnancy among an inner-city cohort. Science.gov (United States) Williams, Megan K; Barr, Dana B; Camann, David E; Cruz, Linda A; Carlton, Elizabeth J; Borjas, Mejico; Reyes, Andria; Evans, Dave; Kinney, Patrick L; Whitehead, Ralph D; Perera, Frederica P; Matsoanne, Stephen; Whyatt, Robin M 2006-11-01 We previously reported widespread insecticide exposure during pregnancy among inner-city women from New York City. Here we report on a pilot intervention using integrated pest management (IPM) to reduce pest infestations and residential insecticide exposures among pregnant New York City African-American and Latina women (25 intervention and 27 control homes). The IPM consisted of professional cleaning, sealing of pest entry points, application of low-toxicity pesticides, and education. Cockroach infestation levels and 2-week integrated indoor air samples were collected at baseline and one month postintervention. The insecticides detected in the indoor air samples were also measured in maternal and umbilical cord blood collected at delivery. Cockroach infestations decreased significantly (p = 0.016) after the intervention among intervention cases but not control households. Among the intervention group, levels of piperonyl butoxide (a pyrethroid synergist) were significantly lower in indoor air samples after the intervention (p = 0.016). Insecticides were detected in maternal blood samples collected at delivery from controls but not from the intervention group. The difference was significant for trans-permethrin (p = 0.008) and of borderline significance (p = 0.1) for cis-permethrin and 2-isopropoxyphenol (a propoxur metabolite). To our knowledge, this is the first study to use biologic dosimeters of prenatal pesticide exposure for assessing effectiveness of IPM. These pilot data suggest that IPM is an effective strategy for reducing pest infestation levels and the internal dose of insecticides during pregnancy. 17. A primary care-based health needs assessment in inner city Dublin. LENUS (Irish Health Repository) O'Kelly, C M 2012-02-01 BACKGROUND: In 2001, a primary care-based health needs assessment (HNA) in South Inner City of Dublin identified high levels of morbidity and widespread and frequent use of primary care and specialist hospital services as particular concerns. AIMS: This study aims to determine the primary care health needs of a local community, from the perspective of service users and service providers. METHODS: A similar methodology to our 2001 HNA was adopted, involving semi-structured interviews with a convenience sample of patients attending two general practices and key informants regarding local health issues and health service utilisation. RESULTS: High levels of morbidity and chronic illness were found. A correlation between the local environment and ill-health was identified, as well as high utilisation of primary care services in the area. CONCLUSION: The establishment of a Primary Care Team would begin to address the health needs of the community. 18. Changes in HIV-related hospitalizations during the HAART era in an inner-city hospital. Science.gov (United States) Pulvirenti, Joseph; Muppidi, Uma; Glowacki, Robert; Cristofano, Michael; Baker, Laurie 2007-08-01 We evaluated admissions of HIV-positive persons to an inner-city hospital from 2000 to 2005. There was a decline in the number of substance abusers, homeless persons, injection drug abusers, and African Americans, and there was an increase in patients older than 50 years. There were no significant changes in CD4 counts or in utilization of highly active antiretroviral therapy,m but there were more admissions of persons with HIV RNA levels less than 1000 copies/mL, internal medicine problems, cancers, and skin infections. Changes in the demographics of this patient population may reflect external factors (eg, gentrification of low-income housing areas, opening of a new hospital). Lower viral loads suggest better response in those on a highly active antiretroviral regimen, and changes in diagnoses leading to hospitalization may reflect the aging of the HIV population. 19. Community Learning and University Policy: An Inner-City University Goes Back to School Directory of Open Access Journals (Sweden) Lloyd Axworthy 2016-05-01 Full Text Available For at least a decade now, the University of Winnipeg (U of W, an urban institution on Treaty One land in the heart of the Métis Nation, has challenged existing academic models and practices, and has incorporated strategies that address the social divide between Indigenous and non-Indigenous peoples in order to more effectively serve the learning needs of its surrounding community. This article demonstrates how an inner-city university has used internal policies and programs to help support the self-determination of Indigenous peoples. Six community learning initiatives were recently evaluated for impact. This article will provide an overview of the positive outcomes of these learning initiatives on a community of underrepresented learners. 20. Managing and mitigating extensive subsurface fuel product beneath two inner-city heritage buildings Energy Technology Data Exchange (ETDEWEB) Friedrich, K. [City of Edmonton, AB (Canada); Morton, P.R. [EBA Engineering Consultants Ltd., Edmonton, AB (Canada) 2006-07-01 The management and mitigation of extensive subsurface fuel product beneath two inner-city heritage buildings in Edmonton, Alberta was examined. The presentation was organized under four components: description and planning; scope and risk; design; and implementation. The description and planning section identified the location, buildings, stakeholders, and integration with other activities. The section on scope and risk addressed issues regarding hydrocarbon impacts, remediation ranking (vertical and inclined wells and horizontal wells), remediation modes, and field trials. The section on design identified the remediation components including extraction wells; liquids separation and collection; water treatment; off-gas catalytic oxidation; sensor data acquisition and PLCS system; satellite link for web monitoring and control, and secure and noise-reducing enclosure. Implementation issues were also discussed with reference to horizontal directional drilling and well construction, difficulties and problems, commissioning, remediation progress to-date, and community benefits. tabs., figs. 1. Autonomy and Relatedness in Inner-City Families of Substance Abusing Adolescents. Science.gov (United States) Samuolis, Jessica; Hogue, Aaron; Dauber, Sarah; Liddle, Howard A 2006-01-01 This study examined parent-adolescent autonomous-relatedness functioning in inner-city, ethnic minority families of adolescents exhibiting drug abuse and related problem behaviors. Seventy-four parent-adolescent dyads completed a structured interaction task prior to the start of treatment that was coded using an established autonomous-relatedness measure. Adolescent drug use, externalizing, and internalizing behaviors were assessed. Parents and adolescents completed assessment instruments measuring parenting style and family conflict. Confirmatory factor analysis found significant differences in the underlying dimensions of parent and adolescent autonomous-relatedness in this sample versus previous samples. It was also found that autonomous-relatedness was associated with worse adolescent symptomatology and family impairment. Results based on both self-report and observational measures contribute to the understanding of key family constructs in this population and provide insight for both researchers and the treatment community. 2. Weber's Historical Urban Sociology: City as a Base of Modern Society OpenAIRE Sunar, Lütfi 2011-01-01 Since the beginning of modernity, discussions concerning the development and characteristics of occidental city in the West have played a central role in defining modern society and exploring its origins. In that, both the synchronous emergence of modern society with urbanization and the manifestation of modernity-triggering capitalism as an urban phenomenon have been instrumental. In that regard, early sociologists have focused their attention on urban development and characteristics of occi... 3. Step-Up: Promoting Youth Mental Health and Development in Inner-City High Schools. Science.gov (United States) Alicea, Stacey; Pardo, Gisselle; Conover, Kelly; Gopalan, Geetha; McKay, Mary 2012-06-01 African American and Latino youth who reside in inner-city communities are at heightened risk for compromised mental health, as their neighborhoods are too often associated with serious stressors, including elevated rates of poverty, substance abuse, community violence, as well as scarce youth-supportive resources, and mental health care options. Many aspects of disadvantaged urban contexts have the potential to thwart successful youth development. Adolescents with elevated mental health needs may experience impaired judgment, poor problem-solving skills, and conflictual interpersonal relationships, resulting in unsafe sexual behavior and drug use. However, mental health services are frequently avoided by urban adolescents who could gain substantial benefit from care. Thus, the development of culturally sensitive, contextually relevant and effective services for urban, low-income African American and Latino adolescents is critical. Given the complexity of the mental health and social needs of urban youth, novel approaches to service delivery may need to consider individual (i.e., motivation to succeed in the future), family (i.e., adult support within and outside of the family), and community-level (i.e., work and school opportunities) clinical components. Step-Up, a high school-based mental health service delivery model has been developed to bolster key family, youth and school processes related to youth mental health and positive youth development. Step-Up (1) intervenes with urban minority adolescents across inner-city ecological domains; (2) addresses multiple levels (school, family and community) in order to target youth mental health difficulties; and (3) provides opportunities for increasing youth social problem-solving and life skills. Further, Step-Up integrates existing theory-driven, evidence-based interventions. This article describes Step-Up clinical goals, theoretical influences, as well as components and key features, and presents preliminary data on 4. Do breastfeeding intentions of pregnant inner-city teens and adult women differ? Science.gov (United States) Alexander, Ashley; O'Riordan, Mary Ann; Furman, Lydia 2010-12-01 This study compared the breastfeeding intentions and attitudes of pregnant low-income inner-city teens (age ≤19 years) and non-teens (age ≥20) to determine if age is a significant determinant of intent to breastfeed in this population. We used structured interviews to examine the feeding intentions and attitudes of consecutive healthy pregnant women receiving obstetrical care at the Women's Health Center, MacDonald Women's Hospital, Cleveland, OH (June 1-July 31, 2007). The primary outcome measure was rate of intent to breastfeed among teen versus non-teen participants. Attitudes and self-assessed knowledge regarding breastfeeding were compared between teens and non-teens, and multiple logistic regression analysis was used to examine the effect of age on breastfeeding intent. We interviewed 176 pregnant women (95% African-American, 94% single marital status, median age 22 years [range, 15-41 years], 46 [26%] teens) at a median of 27 weeks of pregnancy. There were no significant differences between teens and non-teens in race, marital status, or timing of first prenatal visit or interview. Rate of intent to breastfeed and planned duration and exclusivity of breastfeeding, as well as most measured attitudes about breastfeeding including "back to work" plans, were not significantly different between groups. Significant determinants of feeding intent included primiparity, good self-assessed knowledge about breastfeeding, and having support from the father of the baby. In a population at high risk for choosing not to breastfeed, we found no significant explanatory effect of age on breastfeeding intention, implying that an inclusive targeted breastfeeding intervention program may be effective for both teens and non-teens in a low-income inner-city population. We also found that the support of the father of the baby significantly influenced breastfeeding intent among our participants, suggesting that paternal involvement will be integral to the success of 5. Early-life home environment and risk of asthma among inner-city children. Science.gov (United States) O'Connor, George T; Lynch, Susan V; Bloomberg, Gordon R; Kattan, Meyer; Wood, Robert A; Gergen, Peter J; Jaffee, Katy F; Calatroni, Agustin; Bacharier, Leonard B; Beigelman, Avrahman; Sandel, Megan T; Johnson, Christine C; Faruqi, Ali; Santee, Clark; Fujimura, Kei E; Fadrosh, Douglas; Boushey, Homer; Visness, Cynthia M; Gern, James E 2018-04-01 Environmental exposures in early life appear to play an important role in the pathogenesis of childhood asthma, but the potentially modifiable exposures that lead to asthma remain uncertain. We sought to identify early-life environmental risk factors for childhood asthma in a birth cohort of high-risk inner-city children. We examined the relationship of prenatal and early-life environmental factors to the occurrence of asthma at 7 years of age among 442 children. Higher house dust concentrations of cockroach, mouse, and cat allergens in the first 3 years of life were associated with lower risk of asthma (for cockroach allergen: odds ratio per interquartile range increase in concentration, 0.55; 95% CI, 0.36-0.86; P < .01). House dust microbiome analysis using 16S ribosomal RNA sequencing identified 202 and 171 bacterial taxa that were significantly (false discovery rate < 0.05) more or less abundant, respectively, in the homes of children with asthma. A majority of these bacteria were significantly correlated with 1 of more allergen concentrations. Other factors associated significantly positively with asthma included umbilical cord plasma cotinine concentration (odds ratio per geometric SD increase in concentration, 1.76; 95% CI, 1.00-3.09; P = .048) and maternal stress and depression scores. Among high-risk inner-city children, higher indoor levels of pet or pest allergens in infancy were associated with lower risk of asthma. The abundance of a number of bacterial taxa in house dust was associated with increased or decreased asthma risk. Prenatal tobacco smoke exposure and higher maternal stress and depression scores in early life were associated with increased asthma risk. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. All rights reserved. 6. High prevalence of overweight and obesity among inner city Chinese children in Shanghai, 2011. Science.gov (United States) Jiang, Xiao-Xiao; Hardy, Louise L; Baur, Louise A; Ding, Ding; Wang, Ling; Shi, Hui-Jing 2014-01-01 In China, the prevalence of overweight and obesity appears to be increasing at unacceptable levels among young people living in major cities undergoing rapid economic growth. To report the prevalence of overweight and obesity among Shanghai inner city youth using the recently published International Obesity Task Force (IOTF) Asian definition. Secondary analysis of children aged 8-15 years who participated in the Shanghai Schools' Physical Fitness Examinations, a representative school-based survey. Height and weight were measured and body mass index (kg/m(2)) was calculated. The prevalence of overweight and obesity was determined using the IOTF children's BMI cut-points for Asian populations, equivalent to an adult BMI of 23 g/m(2) (overweight) and 27 kg/m(2) (obese). The prevalence of combined overweight and obesity was 49.1% for boys and 30.8% for girls aged 8-15-years. Almost one-in-five boys were obese, compared with 8.4% of girls. In boys the prevalence of overweight appeared to increase from age 10 years. The high prevalence of combined overweight and obesity among urban Chinese youth, especially among boys, requires immediate health promotion intervention. 7. Burden of asthma among inner-city children from Southern Brazil. Science.gov (United States) Roncada, Cristian; de Oliveira, Suelen Goecks; Cidade, Simone Falcão; Sarria, Edgar Enrique; Mattiello, Rita; Ojeda, Beatriz Sebben; Dos Santos, Beatriz Regina Lara; Gustavo, Andréia da Silva; Pinto, Leonardo Araújo; Jones, Marcus Herbert; Stein, Renato Tetelbom; Pitrez, Paulo Márcio 2016-06-01 To assess the impact of asthma in a population of inner-city Brazilian children. In a cross-sectional study, we selected children with asthma and healthy controls from public schools (8-16 years) from a capital city of Southern Brazil. Divided into three phases, questionnaires were administered, assessing lung function, body mass index and allergic sensitization. From 2500 children initially included in the study (48.4% males; mean age of 11.42 ± 2.32 years), asthma prevalence was detected in 28.6% (715/2500). The disease was not controlled in 42.7% (305/715) of the children, with 7.6% of hospitalization rate. School absenteeism (at least one day of missing school because of asthma) and sedentary behavior were high (57.1 and 67.2%, respectively), with 47.9% of subjects requiring oral steroids in the previous year, and physical well-being significantly lower than controls, directly interfering with quality of life, and therefore in the daily activities of these students. Moreover, 38% of the parents admitted to being non-adherent to treatment with their children and 31.1 and 53.6%, respectively, believed that rescue medication and exercise might be harmful. The burden of asthma in Brazilian children seems to be substantial. New international guidelines with a special focus in developing countries settings, with more pragmatic approaches, should be a priority for discussion and implementation actions. 8. Perbandingan Perhitungan Trafik Jam Sibuk CDMA 2000 1x pada BTS Inner City dan BTS Outer City dengan Mempergunakan Metode ADPH, TCBH, FDMH dan FDMP Directory of Open Access Journals (Sweden) Eka Wahyudi 2013-11-01 Full Text Available Cellular communication system is a wireless communication system where the subscriber can move within a wide network coverage. Code Division Multiple Access (CDMA is a multiuser access technology that is each user uses a unique code contained in the access channel in the system. Calculation and determination of peak hours can be done by several methods such as: Average Daily Peak Hour (ADPH, Time Consistent Busy Hour (TCBH, Fixed Daily Measurement Hour (FDMH, Fixed Daily Measurement Period (FDMP. The effectiveness of the channel should be determined by occupancy both at inner city territory and outer city territory location. Using design Erlang (Erl for supply channel at Base Transceiver Station (BTS that provided, BTS has a design Erlang of 369,83 Erl at inner city and it has a design Erlang of 241,8 Erl at outer city. Peak hour on the inner city occurred at 12:00 to 15:00, whereas the outer city of peak hour occurred at 18:00 to 21:00. Effectiveness value that determined by operator are : 70% = high occupancy (very effective. In this case occupancy values obtained in each method is between 21% to 69% which means effective 9. Perfiles Latinoamericanos: Regional sociology, connected sociologies Directory of Open Access Journals (Sweden) Nelson Arteaga Botello 2017-07-01 Full Text Available The landscape of sociology published in the 48 numbers of the Perfiles Latinoamericanos magazineis analyzed. The diversity of topics, perspectives, and methodologies of the articles define aseries of fields of reflection around civil society, collective action, subjectivities and social identities,cities, media, violence, and theory. The essay suggests how the sociology that is producedin Latin America is not isolated but connected with international debates. It converges forms ofdoing theory and research with resonances on a global scale. 10. Cervical, anal and oral HPV in an adolescent inner-city health clinic providing free vaccinations. Directory of Open Access Journals (Sweden) Nicolas F Schlecht Full Text Available Published human papillomavirus (HPV vaccine trials indicate efficacy is strongest for those naive to the vaccine-types. However, few high-risk young women have been followed and cervical HPV has been the predominant outcome measure.We collected cervical and anal swabs, as well as oral rinse specimens from 645 sexually active inner-city young females attending a large adolescent health-clinic in New York City that offers free care and HPV vaccination. Specimens were tested for HPV-DNA using a MY09/MY11-PCR system. Type-specific prevalence of HPV at each anatomic site was compared for individuals by vaccination dose using generalized estimating equation logistic regression models.The majority of subjects reported being of non-Caucasian (92% and/or Hispanic ethnicity (61%. Median age was 18 years (range:14-20. All had practiced vaginal sex, a third (33% practiced anal sex, and most (77% had also engaged in oral sex. At enrollment, 21% had not received the vaccine and 51% had received three doses. Prevalent HPV infection at enrollment was detected in 54% of cervical, 42% of anal and 20% of oral specimens, with vaccine types present in 7%, 6% and 1% of specimens, respectively. Comparing prevalence for vaccine types, the detection of HPV in the cervix of vaccinated compared to unvaccinated adolescents was significantly reduced: HPV6/11 (odds ratio [OR] = 0.19, 95%CI:0.06-0.75, HPV16 (OR = 0.31, 95%CI:0.11-0.88 and HPV18 (OR = 0.14, 95%CI:0.03-0.75. For anal HPV, the risk of detecting vaccine types HPV6/11 (OR = 0.27, 95%CI:0.10-0.72 and HPV18(OR = 0.12, 95%CI:0.01-1.16 were significantly reduced for vaccinated adolescents however, the risk for HPV16 was not significantly decreased (OR = 0.63, 95%CI:0.18-2.20.HPV Prevalence is extremely high in inner-city female adolescents. Administration of the HPV vaccine reduced the risk for cervical HPV; however continued follow-up is required to assess the protection for HPV at all sites 11. The Sociology of the Deceased Harvard Medical Unit at Boston City Hospital. Science.gov (United States) Tishler, Peter V 2015-12-01 Many graduates of the Harvard Medical Unit (HMU) at Boston City Hospital, in either the clinical training/residency program or the research program at the Thorndike Memorial Laboratory, contributed in major ways to the HMU and constantly relived their HMU experiences. The HMU staff physicians, descending from founder and mentor physicians Francis W. Peabody, Soma Weiss, and George R. Minot, were dedicated to the teaching, development, and leadership of its clinical and research trainees, whose confidence and dedication to patient care as a result of their mentorship led many to lifelong achievements as clinicians, teachers, and mentors. Their experience also led to a lifelong love of the HMU (despite its loss), camaraderie, happiness, and intense friendships with their associates. 12. The Sociology of the Deceased Harvard Medical Unit at Boston City Hospital Science.gov (United States) Tishler, Peter V. 2015-01-01 Many graduates of the Harvard Medical Unit (HMU) at Boston City Hospital, in either the clinical training/residency program or the research program at the Thorndike Memorial Laboratory, contributed in major ways to the HMU and constantly relived their HMU experiences. The HMU staff physicians, descending from founder and mentor physicians Francis W. Peabody, Soma Weiss, and George R. Minot, were dedicated to the teaching, development, and leadership of its clinical and research trainees, whose confidence and dedication to patient care as a result of their mentorship led many to lifelong achievements as clinicians, teachers, and mentors. Their experience also led to a lifelong love of the HMU (despite its loss), camaraderie, happiness, and intense friendships with their associates. PMID:26604868 13. Disappointing performance of literature-derived selective screening criteria for asymptomatic Chlamydia trachomatis infection in an inner-city population NARCIS (Netherlands) van Valkengoed, I G; Boeke, A J; Morré, S A; van den Brule, A J; Meijer, C J; Devillé, W; Bouter, L M 2000-01-01 BACKGROUND: In an inner-city population with a low prevalence of Chlamydia trachomatis infection, selective screening may be indicated to increase the efficiency of screening. GOAL: To evaluate the performance of sets of selective screening criteria for asymptomatic Chlamydia trachomatis infection 14. Critical reflections on a visit to an inner-city primary health care clinic in Rio de Janeiro Directory of Open Access Journals (Sweden) Louis S. Jenkins 2017-07-01 Conclusion: Brazil has made massive progress in providing universal health coverage over the last 20 years. South Africa, with not too dissimilar challenges, is embarking on this road more recently. The lessons learnt at clinic and community level in this inner-city clinic could be very useful for similar settings in South Africa and other countries. 15. Treating Anxiety Disorders in Inner City Schools: Results from a Pilot Randomized Controlled Trial Comparing CBT and Usual Care Science.gov (United States) Ginsburg, Golda S.; Becker, Kimberly D.; Drazdowski, Tess K.; Tein, Jenn-Yun 2012-01-01 Background: The effectiveness of cognitive-behavioral treatment (CBT) in inner city schools, when delivered by novice CBT clinicians, and compared to usual care (UC), is unknown. Objective: This pilot study addressed this issue by comparing a modular CBT for anxiety disorders to UC in a sample of 32 volunteer youth (mean age 10.28 years, 63%… 16. Dating-Partner Preferences among a Group of Inner-City African-American High School Students. Science.gov (United States) Smith, Sherry P. 1996-01-01 Examines a set of characteristics that African American inner-city high school students may or may not value in a dating partner. A total of 80 students indicated how important they perceived certain qualities to be in a person they would like to date. The results are in contrast to the previous literature regarding dating-partner preferences… 17. Viet Nam. Grade Six, Unit One. 6.1. Comprehensive Social Studies Curriculum for the Inner City. Science.gov (United States) Thompson, Fred This sixth grade unit is one of a sequential learning series of the Focus On Inner City Social Studies (FICSS) project developed in accordance with the needs and problems of an urban society. A description of the project is provided in SO 008 271. The units are designed to help students investigate the conditions under which people in other… 18. Training for Inner City Parents in Child Rearing: Why Fried Chicken Franchises for Parenting Don't Work. Science.gov (United States) James, Richard; Etheridge, George In an effort to examine the effectiveness of commercially produced parent education programs, a child management and communication class given for Memphis, Tennessee, inner city parents is evaluated in this paper. The program, sponsored by the Mid-South Teacher Corps Project, utilized two models: (1) Becker's 1971 "Parents Are Teachers: A… 19. Parental perception of childhood obesity in an inner-city area of Palermo, Italy Directory of Open Access Journals (Sweden) Bianco Antonino 2008-09-01 Full Text Available Background: The objective of this study was to evaluate in a sample of parents living in an inner-city area of Palermo, Italy, the perception of weight excess as a problem in childhood and the awareness about the role of physical activity, beliefs about contributors and parties having responsibility in counteracting the obesity crisis. Methods: A cross-sectional survey was performed on a convenience sample of parents of 6-13 year-old children who attended grades 1, 3 and 5 of primary and grades 1 and 3 of secondary public schools, respectively. Thirteen schools were selected in an inner urban district of Palermo, Italy, this district being characterized by having a population of low to medium income residents. Parents were asked to come to the school and participate in the investigation. The survey was administered in the spring of 2006. After a descriptive analysis, role of specific demographic and social characteristics – education, gender, age class and BMI - of respondents was assessed by univariate and multivariate logistic regression analysis. Results: Three hundred eleven parents completed the questionnaire. Eighty-three percent believed that being obese in childhood is a serious health hazard, but one third still interpreted the child’s weight excess as an expression of health. The most significant contributors to childhood obesity were thought to be junk food and beverages (78.0% and fast food (63.2%, followed by lack of exercise in school curriculum (48.7%. Beliefs about responsibilities for combating childhood obesity significantly varied according to education level. Conclusions: Public support for environmental changes could more effectively rise with the increasing public awareness that many interrelated obesogenic factors in the modern environment are playing a key role. 20. Cognition, Health Literacy, and Actual and Perceived Medicare Knowledge Among Inner-City Medicare Beneficiaries. Science.gov (United States) Sivakumar, Haran; Hanoch, Yaniv; Barnes, Andrew J; Federman, Alex D 2016-01-01 Poor Medicare knowledge is associated with worse health outcomes, especially in low-income patients. We examined the association of health literacy and cognition with actual and perceived Medicare knowledge in a sample of inner-city older adults. We conducted a cross-sectional analysis of data on 336 adults ages 65 years and older with Medicare coverage recruited from senior centers and low-income housing facilities in Manhattan, New York. Actual Medicare knowledge was determined by a summary score of 9 true/false questions about the Medicare program and perceived Medicare knowledge with a single item. Validated measures were used to assess health literacy and general cognition. Among respondents, 63.1% had high actual Medicare knowledge, and 36.0% believed that they knew what they needed to know about Medicare. Actual and perceived Medicare knowledge were poorly correlated (r = -.01, p > .05). In multivariable models, low health literacy was significantly associated with actual Medicare knowledge (β = -8.30, SE = 2.71, p information about the Medicare program and diminish their ability to make fully informed choices. 1. Sex work, reform initiatives and HIV/AIDS in inner-city Johannesburg. Science.gov (United States) Richter, Marlise 2008-11-01 The on-going criminalisation of sex work in South Africa, concurrent sexual partnerships, socio-economic vulnerability, migrant status and gender-based violence intensify sex workers' risk of contracting HIV. These factors combine to restrict the skills, ability and resources of sex workers to negotiate safer sex and to access HIV prevention, treatment and healthcare services. The paper situates the living and working conditions of sex workers in Hillbrow, an inner-city area of Johannesburg, within the South African legal context, especially in regard to current law reform initiatives regarding sex work, as well as the increasing anxiety about the influx of (sex) tourists during the 2010 FIFA World Cup. In addition, the paper describes an intervention by the Reproductive Health & HIV Research Unit at the University of the Witwatersrand, Johannesburg, an innovator in providing mobile healthcare services and education to hotel-based sex workers in Hillbrow. The paper contends that a legal-rights-approach to HIV risk and vulnerability, together with powerful public health considerations, render decriminalisation an imperative response to sex workers' material conditions. 2. Practising chaordic beauty: On embracing strangers in one inner city faith community Directory of Open Access Journals (Sweden) Stephan de Beer 2016-11-01 Full Text Available In this article I read one inner city faith community – the Tshwane Leadership Foundation (TLF – through the lenses of literature that reflects on chaordic organisations and chaordic leadership. I explore whether an emphasis on the management of diversity, which is widespread in organisational and ecclesial practices and languages, should not be replaced with a spirituality of vulnerable embrace, as I discover it in this specific faith community. It is a spirituality that combines an invitation and radical embrace of diversity, and a dance with chaos, with a posture of vulnerability and a vision of justice. I bring the reflections of community members in TLF on difference and diversity in their organisation, in conversation with scholars contemplating chaordic organisations and chaordic leadership. I then wonder whether their emphasis on embrace instead of management does not open up the possibility of retrieving and affirming the hidden beauties and potentialities mediated by diversity, which is, I suggest, to practise ‘chaordic beauty’. 3. Vision-Based Steering Control, Speed Assistance and Localization for Inner-City Vehicles Science.gov (United States) Olivares-Mendez, Miguel Angel; Sanchez-Lopez, Jose Luis; Jimenez, Felipe; Campoy, Pascual; Sajadi-Alamdari, Seyed Amin; Voos, Holger 2016-01-01 Autonomous route following with road vehicles has gained popularity in the last few decades. In order to provide highly automated driver assistance systems, different types and combinations of sensors have been presented in the literature. However, most of these approaches apply quite sophisticated and expensive sensors, and hence, the development of a cost-efficient solution still remains a challenging problem. This work proposes the use of a single monocular camera sensor for an automatic steering control, speed assistance for the driver and localization of the vehicle on a road. Herein, we assume that the vehicle is mainly traveling along a predefined path, such as in public transport. A computer vision approach is presented to detect a line painted on the road, which defines the path to follow. Visual markers with a special design painted on the road provide information to localize the vehicle and to assist in its speed control. Furthermore, a vision-based control system, which keeps the vehicle on the predefined path under inner-city speed constraints, is also presented. Real driving tests with a commercial car on a closed circuit finally prove the applicability of the derived approach. In these tests, the car reached a maximum speed of 48 km/h and successfully traveled a distance of 7 km without the intervention of a human driver and any interruption. PMID:26978365 4. Vision-Based Steering Control, Speed Assistance and Localization for Inner-City Vehicles Directory of Open Access Journals (Sweden) Miguel Angel Olivares-Mendez 2016-03-01 Full Text Available Autonomous route following with road vehicles has gained popularity in the last few decades. In order to provide highly automated driver assistance systems, different types and combinations of sensors have been presented in the literature. However, most of these approaches apply quite sophisticated and expensive sensors, and hence, the development of a cost-efficient solution still remains a challenging problem. This work proposes the use of a single monocular camera sensor for an automatic steering control, speed assistance for the driver and localization of the vehicle on a road. Herein, we assume that the vehicle is mainly traveling along a predefined path, such as in public transport. A computer vision approach is presented to detect a line painted on the road, which defines the path to follow. Visual markers with a special design painted on the road provide information to localize the vehicle and to assist in its speed control. Furthermore, a vision-based control system, which keeps the vehicle on the predefined path under inner-city speed constraints, is also presented. Real driving tests with a commercial car on a closed circuit finally prove the applicability of the derived approach. In these tests, the car reached a maximum speed of 48 km/h and successfully traveled a distance of 7 km without the intervention of a human driver and any interruption. 5. Vision-Based Steering Control, Speed Assistance and Localization for Inner-City Vehicles. Science.gov (United States) Olivares-Mendez, Miguel Angel; Sanchez-Lopez, Jose Luis; Jimenez, Felipe; Campoy, Pascual; Sajadi-Alamdari, Seyed Amin; Voos, Holger 2016-03-11 Autonomous route following with road vehicles has gained popularity in the last few decades. In order to provide highly automated driver assistance systems, different types and combinations of sensors have been presented in the literature. However, most of these approaches apply quite sophisticated and expensive sensors, and hence, the development of a cost-efficient solution still remains a challenging problem. This work proposes the use of a single monocular camera sensor for an automatic steering control, speed assistance for the driver and localization of the vehicle on a road. Herein, we assume that the vehicle is mainly traveling along a predefined path, such as in public transport. A computer vision approach is presented to detect a line painted on the road, which defines the path to follow. Visual markers with a special design painted on the road provide information to localize the vehicle and to assist in its speed control. Furthermore, a vision-based control system, which keeps the vehicle on the predefined path under inner-city speed constraints, is also presented. Real driving tests with a commercial car on a closed circuit finally prove the applicability of the derived approach. In these tests, the car reached a maximum speed of 48 km/h and successfully traveled a distance of 7 km without the intervention of a human driver and any interruption. 6. Sociological Perspectives. Science.gov (United States) Townley, Charles; Middleton, Mike This monograph examines sociological perspectives and their applications. It is intended to help the college student coming to sociology for the first time to recognize that there are several perspectives within sociology and to disentangle the mass of terms associated with each. The first distinctive sociological perspective came from the work of… 7. Bidirectional Relationships Between Parenting Processes and Deviance in a Sample of Inner-City African American Youth Science.gov (United States) Harris, Charlene; Vazsonyi, Alexander T.; Bolland, John M. 2016-01-01 The current study assessed for bidirectional relationships among supportive parenting (knowledge), negative parenting (permissiveness), and deviance in a sample (N = 5,325) of poor, inner-city African American youth from the Mobile Youth Survey (MYS) over 4 years. Cross-lagged path analysis provided evidence of significant bidirectional paths among parenting processes (knowledge and permissiveness) and deviance over time. Follow-up multigroup tests provided only modest evidence of dissimilar relationships by sex and by developmental periods. The findings improve our understanding of developmental changes between parenting behaviors and deviance during adolescence and extended current research of the bidirectionality of parent and child relationships among inner-city African American youth. PMID:28316460 8. Determinants of adult vaccination at inner-city health centers: A descriptive study Directory of Open Access Journals (Sweden) Raymund Mahlon 2006-01-01 Full Text Available Abstract Background Pneumococcal polysaccharide vaccination rates among adults 65 years and older or less than 65 years with high risk medical conditions are still below Healthy People 2010 recommended levels of 90%. This study was designed to: 1 assess self-reported pneumococcal vaccination rates following health center level interventions to increase adult vaccination rates; and 2 determine factors associated with vaccination. Methods Tailored interventions to increase immunizations were implemented at two inner-city health centers. We surveyed 375 patients 50 years of age and older. Multivariate logistic regression examines the predictors of 1 self-reported pneumococcal vaccination and 2 combined self-reported influenza and pneumococcal vaccination. Both of these models were stratified by age group (50–64 years and 65 years and older. Results Pneumococcal vaccination rates were 45% by self-report, 55% by medical record review, 69% for patients 65 years old and older, 32% for patients 50–64 years; they did not differ by race. Receipt of the previous season's influenza vaccine was significantly related to pneumococcal vaccination among both younger and older patients. Receiving both the pneumococcal vaccine and the most recent influenza vaccine compared with receiving neither, among younger patients was related to unemployment, more frequent physician visits, and belief that those who do not receive the flu shot are more susceptible to the flu. For older patients, receipt of both vaccines was related to nonsmoking status, believing that friends/family think the patient should be vaccinated, seeing posters advertising flu shot clinics, and belief that those who do not receive the flu shot are more susceptible to the flu. Conclusion Our findings suggest that improving overall pneumococcal vaccination rates among eligible adults, has the potential to eliminate racial disparities. Interventions delivering vaccination messages specific to older 9. Inner city air pollution and respiratory health and atopy in children Energy Technology Data Exchange (ETDEWEB) Hirsch, T.; Safeca, A.F.; Leupold, W. [Univ. Children' s Hospital Dresden (Germany); Weiland, S.K.; Duhme, H.; Keil, U. [Univ. of Muenster, Inst. of Epidemiology and Social Medicine (Germany); Mutius, E. von [Univ. Children' s Hospital, Klinikum Innenstadt, Munich (Germany); Graefe, H. [Saxony State Agency for Environment and Geology, Radebeul (Germany); Csaplovics, E. [Univ. of Technology, Inst. of Photogrammetry and Remote Sensing, Dresden (Germany) 1999-09-01 The impact of inner city air pollution on the development of respiratory and atopic diseases in childhood is still unclear. In a cross sectional study in Dresden, Germany, 5,421 children in two age groups (5-7 yrs and 9-11 yrs) were studied according to the International Study of Asthma and Allergies in Childhood (ISAAC) phase II protocol, The prevalences of wheezing and cough as well as doctor diagnosed asthma and bronchitis were assessed by parental questionnaires. Children also underwent skin-prick testing, venepuncture for the measurement of serum immunoglobulin (Ig)E, lung function testing and a bronchial challenge test (4.5% saline) to assess airway hyperresponsiveness. Exposure was assessed on an individual basis by relating mean annual air pollution levels (SO{sub 2}, NO{sub 2}, CO, benzene, and O{sub 3}) which had been measured on a 1 km{sup 2} grid, to the home and school address of each study subject. After adjusting for potential confounding factors an increase in the exposure to benzene of 1 {mu}g{center{underscore}dot}m{sup 3} air was associated with an increased prevalence of morning cough (adjusted odds ratio (aOR): 1.15; 1.04-1.27) and bronchitis (aOR: 1.11; 1.03-1.19). Similar associations were observed for NO{sub 2} and CO. In turn, the prevalences of atopic sensitization, symptoms of atopic diseases and bronchial hyperresponsiveness were not positively associated with exposure to any of these pollutants. It is concluded that in this study a moderate increase in exposure to traffic-related air pollution was associated with an increased prevalence of cough and bronchitis, but not with atopic conditions in children. (au) 10. Effect of Gender on the Response to Hepatitis C Treatment in an Inner-City Population. Science.gov (United States) Simoes, Priya; Asaad, Adel; Abed, Jean; Engelson, Ellen S; Kotler, Donald P 2015-01-01 Hepatitis C virus (HCV) is the leading cause of cirrhosis, hepatocellular carcinoma, and liver transplantation in the United States. Response to treatment has improved with the addition of direct acting protease inhibitors. However, there are limited real-world data on the role of gender in achieving a sustained virologic response (SVR). We conducted a cross-sectional study in 70 patients treated for HCV, genotype 1 infection with pegylated alpha interferon, ribavirin, and either telaprevir or boceprevir at our inner-city liver clinic. The SVR was significantly lower in women than in men (24% vs. 59%; p < .01). Statistical significance persisted after adjusting for age, race, genotype, prior treatment status, duration of therapy, and stage of fibrosis. The adjusted odds ratio for achieving SVR was significantly lower in women than in men (odds ratio [OR], 0.13; 95% CI, 0.03-0.58; p = .01). Relapse after completing treatment was more likely to occur in women (p = .02). Thirty-four patients (48%) did not complete therapy. Discontinuation because of loss to follow-up was more likely in women, whereas discontinuation owing to therapy limiting adverse drug events were more common in men. Discontinuation rates owing to failure of therapy were similar in men and women. There was a significant difference in SVR between men and women. Both biological and nonbiological factors, the latter including access to care, adherence to therapy, and attitudes of and toward health care providers all could play a role in contributing to the observed disparity between sexes in treatment response. Copyright © 2015 Jacobs Institute of Women's Health. Published by Elsevier Inc. All rights reserved. 11. Technology Integration in a Southern Inner-City School: Perspectives of In-service and Preservice Teachers Science.gov (United States) 2013-07-25 researcher that: TECHNOLOGY IN AN INNER-CITY SCHOOL 11 Technology is wonderful in the classroom, especially for little kids . You can use...As far as writing, I can see that [hands-on vs. clicking; and hands-on is better]. We did not get to use the computer as much as kids do today. I...that teachers receive the training needed for them to implement the best instructional practices. Second, the pedagogical shift from traditional 12. Impact on and use of an inner-city London Infectious Diseases Department by international migrants: a questionnaire survey OpenAIRE Cooke, Graham; Hargreaves, Sally; Natkunarajah, Jana; Sandhu, Gurjinder; Dhasmana, Devesh; Eliahoo, Joseph; Holmes, Alison; Friedland, Jon S 2007-01-01 Abstract Background The UK has witnessed a considerable increase in immigration in the past decade. Migrant may face barriers to accessing appropriate health care on arrival and the current focus on screening certain migrants for tuberculosis on arrival is considered inadequate. We assessed the implications for an inner-city London Infectious Diseases Department in a high migrant area. Methods We administered an anonymous 20-point questionnaire survey to all admitted patients during a 6 week ... 13. Testing the Efficacy of INSIGHTS on Student Disruptive Behavior, Classroom Management, and Student Competence in Inner City Primary Grades OpenAIRE McClowry, Sandra Graham; Snow, David L.; Tamis-LeMonda, Catherine S.; Rodriguez, Eileen T. 2009-01-01 A prevention trial tested the efficacy of INSIGHTS into Children?s Temperament as compared to a Read Aloud attention control condition in reducing student disruptive behavior and enhancing student competence and teacher classroom management. Participants included 116 first and second grade students, their parents, and their 42 teachers in six inner city schools. Teachers completed the Sutter-Eyberg Student Behavior Inventory (SESBI) and the Teacher?s Rating Scale of Child?s Actual Competence ... 14. Factors Associated with Noncompletion of Latent Tuberculosis Infection Treatment in an Inner-City Population in Edmonton, Alberta Directory of Open Access Journals (Sweden) Kathy Malejczyk 2014-01-01 Full Text Available A limited number of studies have been published that examine treatment completion rates and interventions used to increase treatment completion within an inner-city population. The purpose of the present study was to determine the rate of latent tuberculosis infection (LTBI treatment completion in an inner-city population in Edmonton, Alberta, and to identify factors that correlated with treatment completion. A retrospective chart review was conducted involving patients who started LTBI treatment between January 1, 2005 and December 31, 2010 in Edmonton’s inner city. A total of 77 patients started treatment and 57 (74% patients completed LTBI treatment. Homelessness was the only variable that was significantly associated with incomplete treatment (OR 8.0 [95% CI 1.4 to 45.6] and it remained significant when controlling for drug use (adjusted OR 6.5 [95% CI 1.1 to 38.8]. While the present study demonstrated treatment completion rates comparable with or better than those described in the general population, it highlighted the need for continued emphasis on interventions aimed at improving outcomes within homeless populations. 15. Public Sociology DEFF Research Database (Denmark) by the media? Does the choice of public sociology mean the relinquishment of scientific integrity and critical conviction? These questions will also be addressed in this book - together with a host of others related to the topic of public sociology. The chapters included in this book are all manuscripts......What is the role of sociology in society? How can - and should - sociology contribute with insights relevant and useful to the outside world? Is sociology attuned to accommodate the demands of the wider public and of surrounding society? Who benefits from the knowledge produced and provided...... by sociology? What are the social implications and cultural effects of the knowledge sociology provides and creates? All of these questions, and many others, concern and centre on sociology's relationship to the surrounding society, in short to the ‘public'. All of these questions - and many others... 16. Inverse correlation between Helicobacter pylori colonization and obesity in a cohort of inner city children. Science.gov (United States) Vo, Hanh D; Goli, Sridhar; Gill, Rupinder; Anderson, Virginia; Stefanov, Dimitre G; Xu, Jiliu; Kulsum-Mecci, Nazia; Schwarz, Steven M; Rabinowitz, Simon S 2015-02-01 Recently, publications in adults and children have documented a potential role of Helicobacter pylori (H. pylori) in decreasing the likelihood of obesity. The present study compares the prevalence of H. pylori colonization between obese (body mass index [BMI] ≥ 95th percentile) and healthy weight (BMI ≥ 5th to children seen at an inner city medical center in the United States. This retrospective study reviewed clinical features, BMI, and gastric histology of consecutive children aged 1-18 years undergoing an esophagogastroduodenoscopy. BMI percentile was calculated for age and gender. Helicobacter pylori colonization was determined by histopathologic identification of the organism. Multiple logistic regression was employed to measure the association between BMI and H. pylori colonization, controlling for baseline age, gender, and presenting symptoms. Among 340 patients (51.5% female, mean age of 10.5 ± 4.7 years), 98 (29%) were obese and 173 (51%) were healthy weight. The H. pylori colonization rate of the entire cohort was 18.5% (95% CI = 14.7-23.0%). Among obese children, 10% had H. pylori colonization compared to 21% of the healthy weight children (RR = 2.1, 95% CI = 1.1-4.0). Conversely, 39% of noncolonized children, but only 21% of the infected children, were obese (RR = 1.8, 95% CI = 1.1-3.3). Multivariate analysis revealed that being colonized with H. pylori is associated with a 50% reduction in the odds of being obese (adjusted OR = 0.5, 95% CI = 0.2-1.0). Our findings in a North American cohort are in agreement with studies from Asia and Europe suggesting that H. pylori infection decreases the prevalence of obesity in children. Further work to characterize the extent and nature of this relationship is warranted. © 2014 John Wiley & Sons Ltd. 17. Enhancing their likelihood for a positive future: the perspective of inner-city youth. Science.gov (United States) Ginsburg, Kenneth R; Alexander, Penny M; Hunt, Jean; Sullivan, Maisha; Zhao, Huaqing; Cnaan, Avital 2002-06-01 Inner-city youth must overcome many environmental challenges as they strive for success. Their outcome is influenced by the interplay of protective forces and risk factors. To learn directly from youth what solutions they believe would most influence their likelihood of achieving a positive future. In-school 8th-, 9th-, and 12th-graders in north Philadelphia generated, prioritized, and explained their own solutions through a 4-stage hierarchical process facilitated by AmeriCorps workers. In Stage 1, 60 randomly selected students participated in 8 focus groups to develop the study question. In Stage 2, youth in Nominal Group Technique sessions generated and prioritized solutions. In Stage 3, a survey for each grade that included their top prioritized ideas was distributed, and youth rated each idea on a Likert scale (5= Definitely would make me more likely to have a positive future to 1 = Would definitely not.). One thousand twenty-two ninth-graders (69% of in-school youth at 5 high schools) returned usable surveys. Ninety-three percent of responders were 14 to 16 years old, 44% were male, 54% were black, and 32% were Latino. Four hundred seventeen 8th-graders and 322 12th-graders returned usable surveys. In Stage 4, youth in 10 focus groups added meaning and context to the ideas. The highest rated items in all grades were solutions that promoted education or increased job opportunities. Ninth-graders ranked helping youth get into college first by the Marginal Homogeneity Test. The creation of more jobs was ranked second. Third rank was shared by more job training, keeping youth from dropping out of school, and better books for schools. The next tier of items focused mostly on opportunities for youth to spend their free time productively and to have interactions with adults. Many items calling for the reduction of risk behaviors or disruptive surroundings were rated lower. The Kruskal-Wallis test found little variation in rating of the ideas by gender, race, or 18. Educational Colonoscopy Video Enhances Bowel Preparation Quality and Comprehension in an Inner City Population. Science.gov (United States) Pillai, Ajish; Menon, Radha; Oustecky, David; Ahmad, Asyia 2017-07-24 Quality of bowel preparation and patient knowledge remains a major barrier for completing colorectal cancer screening. Few studies have tested unique ways to impact patient understanding centering on interactive computer programs, pictures, and brochures. Two studies explored instructional videos but focused on patient compliance and anxiety as endpoints. Furthermore, excessive video length and content may limit their impact on a broad patient population. No study so far has studied a video's impact on preparation quality and patient understanding of the colonoscopy procedure. We conducted a single blinded prospective study of inner city patients presenting for a first time screening colonoscopy. During their initial visit patients were randomized to watch an instructional colonoscopy video or a video discussing gastroesophageal reflux disease (GERD). All patients watched a 6 minutes long video with the same spokesperson, completed a demographic questionnaire (Supplemental Digital Content 1, http://links.lww.com/JCG/A352) and were enrolled only if screened within 30 days of their visit. On the day of the colonoscopy, patients completed a 14 question quiz of their knowledge. Blinded endoscopist graded patient preparations based on the Ottawa scale. All authors had access to the study data and reviewed and approved the final manuscript. Among the 104 subjects enrolled in the study, 56 were in the colonoscopy video group, 48 were in GERD video group, and 12 were excluded. Overall, 48% were male and 52% female; 90% of patients had less than a high school education, 76% were African American, and 67% used a 4 L split-dose preparation. There were no differences between either video group with regard to any of the above categories. Comparisons between the 2 groups revealed that the colonoscopy video group had significantly better Ottawa bowel preparation score (4.77 vs. 6.85; P=0.01) than the GERD video group. The colonoscopy video group also had less-inadequate repeat 19. Post-traumatic stress and coping in an inner-city child. Traumatogenic witnessing of interparental violence and murder. Science.gov (United States) Parson, E R 1995-01-01 Violence today appears to be ubiquitous: it even enters the clinical session, deeply internalized within child victims who were exposed to often unspeakable horror. Violence and its pernicious, horrific effects are observed in the streets, schools, parks, playgrounds, and homes of some inner-city communities. This article introduces the use of Anna Freud's Diagnostic Profile system with an inner-city child who, at the age of four, witnessed his mother fatally stab his father with a kitchen knife and at age eleven was assessed and treated by the author. Clinicians may wonder whether any kind of therapy could ever undo the serious fixations, regressions, developmental arrests, and integrate trauma-shattered ego functions observed in children exposed to visual horror and affective terror. Application of the Profile may offer some direction with these children: a panoramic view of their painful mood, their hypervigilance and distrust, fears, separation and annihilation anxieties, nightmares (with murder imagery), developmental anomalies and arrests is presented with clarity and force. The therapist uses countertransference responses to monitor the affect tolerance in the child and to determine the appropriate dosages of awareness the child can integrate from one moment to the next. The therapist also serves as the child's external stimulus barrier and explores feelings about media-driven portrayals of violence, stereotypes, and inner-city children and youths. The unsurpassed utility of the Profile as a diagnostic system that documents vital economic, dynamic, structural, genetic and adaptive-coping information about the child is discussed in detail as is the Profile's added benefit of possibly guarding against misdiagnosis and charting a course for psychotherapy in difficult city-violence trauma cases. 20. Barriers, motivators and facilitators related to prenatal care utilization among inner-city women in Winnipeg, Canada: a case–control study OpenAIRE Heaman, Maureen I; Moffatt, Michael; Elliott, Lawrence; Sword, Wendy; Helewa, Michael E; Morris, Heather; Gregory, Patricia; Tjaden, Lynda; Cook, Catherine 2014-01-01 Background The reasons why women do not obtain prenatal care even when it is available and accessible are complex. Despite Canada’s universally funded health care system, use of prenatal care varies widely across neighborhoods in Winnipeg, Manitoba, with the highest rates of inadequate prenatal care found in eight inner-city neighborhoods. The purpose of this study was to identify barriers, motivators and facilitators related to use of prenatal care among women living in these inner-city neig... 1. Visualising pedestrian flow using PGS tracking to improve inner city quality NARCIS (Netherlands) Van Langelaar, T.; Van der Spek, S.C. 2010-01-01 Every environment has its own characteristics and people react individually to that structure; in an interactive, passive or avoiding way. This paper focuses on pedestrian movement in the city centre of Delft, the Netherlands. It is dedicated to find new and exciting ways of improving city centres 2. Classical Music at a German Inner-City School: The German Philharmonic Chamber Orchestra Bremen at Comprehensive School Bremen East Directory of Open Access Journals (Sweden) Anna-Lena Musiol 2013-12-01 Full Text Available The German Philharmonic Chamber Orchestra Bremen, a world famous orchestra for classical music, and the Comprehensive School Bremen East, a school in a deprived area, in North American terms an inner-city school, are cooperating since 2007. A three-year follow-up evaluation study was conducted to find out, if projects facilitated by the presence of the orchestra have a positive impact on the self-reported well-being and the grades of students. Results showed that involvement in the projects distinctly benefited boys: They experience a better class climate and a higher satisfaction with school as well as improved German grades. 3. Formative research for a healthy diet intervention among inner-city adolescents: the importance of family, school and neighborhood environment. Science.gov (United States) Dodson, Jennifer L; Hsiao, Ya-Chun; Kasat-Shors, Madhuri; Murray, Laura; Nguyen, Nga Kim; Richards, Adam K; Gittelsohn, Joel 2009-01-01 To understand influences on diet among low-income African-American adolescents in East Baltimore. Formative research was conducted for a food store-centered healthy diet intervention targeted to inner-city youth. Family, school and neighborhood influences on eating habits and health concepts were explored. Family structure, economic resources and past experiences influence what food means to adolescents. Healthy food in school and local stores is limited. Terminology to categorize foods was identified, including the term "home foods". Suggested adolescent nutritional interventions include promotion of home-based eating, improving availability of healthy foods in school and neighborhood stores, and targeted educational materials. 4. Orchards for edible cities: cadmium and lead content in nuts, berries, pome and stone fruits harvested within the inner city neighbourhoods in Berlin, Germany. Science.gov (United States) von Hoffen, Laura Pauline; Säumel, Ina 2014-03-01 Today's urban gardening focuses mainly on vegetable production and rarely includes fruit trees. Health effects of consuming urban crops are questioned due to high local pollution loads. Here, we determined cadmium and lead content in the edible parts of nuts, berries, pome, and stone fruits harvested from fruit trees and shrubs within inner city neighbourhoods of Berlin, Germany. We analysed how local settings at sampling sites shaped the trace metal content. We revealed significant differences in trace metal content depending on species, fruit type, local traffic, and parameters related to barriers between the sampling site and neighbouring roads. Higher overall traffic burden and proximity to roads increased whereas buildings or vegetation as barriers reduced trace metal content in the edible biomass. We demonstrate, that the consumption of non-vegetable fruits growing in inner city sites in Berlin does not pose a risk on human health as long as the fruits are thoroughly washed and it is provided that site pollutions and impacts are considered in garden concepts and guidelines. © 2013 Published by Elsevier Inc. 5. The Evolving Law of Disputed Relocation: constructing inner-city renewal practices in Shanghai, 1990-2005. Science.gov (United States) Shih, Mi 2010-01-01 The forceful pursuit of inner-city renewal in Shanghai since the early 1990s has to a great extent achieved spatial modernization, but at the same time it has given rise to increasing conflicts over residential relocation. Using law as a prism through which to examine the dialectic relationship between renewal practices and disputed relocation, this article argues that the series of unprecedented enactments in law that have taken place during this period have both paved the way for real estate market expansion and been a significant source of relocation disputes in Shanghai. Rather than viewing law as simply given and determinate, the article traces the regulatory regime's codification of property practices as a means of actively responding to the requirements of the real estate market. Under large-scale renewal practices, residents' legal rights of "return settlement" (huiban) in inner-city areas were largely denied in the early 1990s, before being effectively abolished by the adoption of monetary compensation for displacement in the 2000s. The evolving law on property practices has greatly shaped the process of disputed relocation while simultaneously posing a potential challenge to China's use of law for market-oriented development. 6. Stroke Outreach in an Inner City Market: A Platform for Identifying African American Males for Stroke Prevention Interventions. Science.gov (United States) Sharrief, Anjail Zarinah; Johnson, Brenda; Urrutia, Victor Cruz 2015-01-01 There are significant racial disparities in stroke incidence and mortality. Health fairs and outreach programs can be used to increase stroke literacy, but they often fail to reach those at highest risk, including African American males. We conducted a stroke outreach and screening program at an inner city market in order to attract a high-risk group for a stroke education intervention. A modified Framingham risk tool was used to estimate stroke risk and a 10-item quiz was developed to assess stroke literacy among 80 participants. We report results of the demographic and stroke risk analyses and stroke knowledge assessment. The program attracted a majority male (70%) and African American (95%) group of participants. Self-reported hypertension (57.5%), tobacco use (40%), and diabetes (23.8%) were prevalent. Knowledge of stroke warning signs, risk factors, and appropriate action to take for stroke symptoms was not poor when compared to the literature. Stroke outreach and screening in an inner city public market may be an effective way to target a high-risk population for stroke prevention interventions. Stroke risk among participants was high despite adequate stroke knowledge. 7. Inner boundary reform in Košice: The most fragmented city in Slovakia Directory of Open Access Journals (Sweden) Csachová Stela 2016-01-01 Full Text Available In the first part of the paper the aim is to provide the reader with a theoretical insight into models of government structure at the local level and provide evidence from European countries that underwent reforms during the second half of the 20th century. In the Slovak Republic (Slovakia the renewal of local self-government in 1990 brought changes to the administrative boundary map with more than 200 municipalities reestablished bringing the current number to 2,929 local administrative units. This has resulted in some discussion regarding a reduction in the number of local government units in this country. The second part of the paper is focused on Košice; the second largest city in Slovakia with 234,000 inhabitants. The city is organised at two administrative levels; one covering the whole city, the other covering 22 wards. When compared to cities of a similar size, Košice has been criticised for its high number of city wards and councillors, with the concomitant financial inefficiency it can bring. There has been an ongoing debate on reducing their number since 2010. The paper reports on the search for an administrative structure that would best tailor to the citizens' needs and provide effective management in Košice. It uses traditional methods of qualitative research (historical method, content analysis and synthesis accompanied by statistical data organised in tables and figures. 8. “Quit stalling…!”: Destiny and Destination on L.A.’s Inner City Roads Directory of Open Access Journals (Sweden) Martin Zeilinger 2009-12-01 Full Text Available If driving has today really become a Western "metaphor for being" (Hutchinson, then common roadside signs proclaiming "Right lane must exit" or "Through traf-fic merge left", inventions such as the automatic transmission, and the agreeable straightness of freeways can all be understood as symptoms of an ongoing socio-political struggle between the driver as democratic agent, and the state as institu-tionalized regulatory force. Nowhere is this more obvious than in the context of urban traffic, where private motorized transportation represents both the supreme (if illusory expression of personal freedom, and official efforts to channel indivi-dualism by obliterating its sense of direction and ideological divergence. On the concrete proving grounds of the clogged inner-city freeway, "nomad science" and "state science" (Deleuze & Guattari thus oscillate between the pseudo-liberatory expressivity of mainstream car culture and the self-effacing dromoscopic "amne-sia of driving" (Baudrillard. Are a city's multitudes of cars resistant "projectiles" (Virilio or, rather, hegemonic "sites of containment" (Jane Jacobs? This essay approaches the complex tensions between "untamable" democratic mobility and state-regulated transit by way of two Hollywood-produced films that focus on traffic in Los Angeles: in Collateral (2004, a cab driver comes to recognize and transcend the hopelessly directionless circularity dictated by his job; in Falling Down (1993, a frustrated civil service employee abandons his car on a rush-hour freeway and decides to walk home, forced to traverse the supposedly unwalkable city without the "masking screen of the windshield" (Virilio. As they "quit stal-ling", both protagonists become dangerous variants of the defiant nomad - one a driver who remains on the road but goes "under the radar", the other a transient pedestrian whose movement becomes viral and unpredictable. My analysis of the films' metropolitan setting and of the 9. Aggression, Victimization and Problem Behavior among Inner-City Minority Adolescents. Science.gov (United States) Epstein, Jennifer A.; Botvin, Gilbert J.; Diaz, Tracy; Williams, Christopher; Griffin, Kenneth 2000-01-01 Eighth graders (N=517) attending three New York City schools completed a questionnaire related to drug use and aggression. Self-reported aggressive and unsafe behaviors were associated with initiation of drug use. Sex differences were found for aggressive behavior, victimization, and unsafe behavior. Implications for prevention programs are… 10. Storylines of self-management: narratives of people with diabetes from a multiethnic inner city population. Science.gov (United States) Greenhalgh, Trisha; Collard, Anna; Campbell-Richards, Desirée; Vijayaraghavan, Shanti; Malik, Farida; Morris, Joanne; Claydon, Anne 2011-01-01 to analyse the narratives of people with diabetes to inform the design of culturally congruent self-management education programmes. the study was based on quasi-naturalistic story-gathering; i.e. making real-time field notes of stories shared spontaneously in diabetes self-management education groups in a socioeconomically deprived London borough. Eighty-two adults aged 25-86, from six minority ethnic groups who were in the intervention arm of a randomized controlled trial of story-sharing, participated. Stories were translated in real time by the facilitator or group members. Ethnographic field notes were transcribed, and analysed thematically (to identify self-management domains raised by participants) and interpretively for over-arching storylines (i.e. considering how self-management domains were contextualized and made meaningful in personal narratives). Analysis was informed by both biomedical and sociological theories of self-management. people with diabetes identified seven self-management domains: knowledge; diet; exercise; medication; foot care; self-monitoring; and attending check-ups. Interpretive analysis revealed eight illness storylines within which these practical issues acquired social meaning and moral worth: becoming sick; rebuilding spoiled identity; becoming a practitioner of self-management; living a disciplined and balanced life; mobilizing a care network; navigating and negotiating in the health care system; managing the micro-morality of self-management 'choices'; and taking collective action. living with diabetes involves both medically recommended behaviours and complex biographical work to make sense of and cope with illness. Self-management education programmes should take closer account of over-arching storylines that pattern experience of chronic illness and recognize that some elements of self-management knowledge cannot be pre-specified in a structured curriculum. The Royal Society of Medicine Press Ltd 2011. 11. Testing the Efficacy of INSIGHTS on Student Disruptive Behavior, Classroom Management, and Student Competence in Inner City Primary Grades. Science.gov (United States) McClowry, Sandra Graham; Snow, David L; Tamis-Lemonda, Catherine S; Rodriguez, Eileen T 2010-03-01 A prevention trial tested the efficacy of INSIGHTS into Children's Temperament as compared to a Read Aloud attention control condition in reducing student disruptive behavior and enhancing student competence and teacher classroom management. Participants included 116 first and second grade students, their parents, and their 42 teachers in six inner city schools. Teachers completed the Sutter-Eyberg Student Behavior Inventory (SESBI) and the Teacher's Rating Scale of Child's Actual Competence and Social Acceptance (TRS) at baseline and again upon completion of the intervention. Boys participating in INSIGHTS, compared with those in the Read Aloud program, showed a significant decline in attentional difficulties and overt aggression toward others. Teachers in INSIGHTS, compared to those in the attention control condition, reported significantly fewer problems managing the emotional-oppositional behavior, attentional difficulties, and covert disruptive behavior of their male students. They also perceived the boys as significantly more cognitively and physically competent. 12. The Role of Empowerment in a School-Based Community Service Program with Inner-City, Minority Youth Science.gov (United States) Gullan, Rebecca L.; Power, Thomas J.; Leff, Stephen S. 2014-01-01 Despite considerable fiscal and structural support for youth service programs, research has not demonstrated consistent outcomes across participants or programs, suggesting the need to identify critical program processes. The present study addresses this need through preliminary examination of the role of program empowerment in promoting positive identity development in inner-city, African American youth participating in a pilot school-based service program. Results suggest that participants who experienced the program as empowering experienced increases in self-efficacy, sense of civic responsibility, and ethnic identity, over and above general engagement and enjoyment of the program. Preliminary exploration of differences based on participant gender suggests that some results may be stronger and more consistent for males than females. These findings provide preliminary support for the importance of theoretically grounded program processes in producing positive outcomes for youth service participants. PMID:25104875 13. Social competence promotion with inner-city and suburban young adolescents: effects on social adjustment and alcohol use. Science.gov (United States) Caplan, M; Weissberg, R P; Grober, J S; Sivo, P J; Grady, K; Jacoby, C 1992-02-01 This study assessed the impact of school-based social competence training on skills, social adjustment, and self-reported substance use of 282 sixth and seventh graders. Training emphasized broad-based competence promotion in conjunction with domain-specific application to substance abuse prevention. The 20-session program comprised six units: stress management, self-esteem, problem solving, substances and health information, assertiveness, and social networks. Findings indicated positive training effects on Ss' skills in handling interpersonal problems and coping with anxiety. Teacher ratings revealed improvements in Ss' constructive conflict resolution with peers, impulse control, and popularity. Self-report ratings indicated gains in problem-solving efficacy. Results suggest some preventive impact on self-reported substance use intentions and excessive alcohol use. In general, the program was found to be beneficial for both inner-city and suburban students. 14. Introduction of wireless, pen-based computing among visiting nurses in the inner city: a qualitative study. Science.gov (United States) Wilson, R; Fulmer, T 1997-01-01 The purpose of this qualitative study is to understand how a sample of visiting nurses experienced the practice of home health nursing in the inner city and how they perceived the anticipated introduction of wireless, pen-based computing into their practice. Focus groups were held with visiting nurses 1 week before the introduction of the wireless, pen-based computers. The data were analyzed using Strauss and Corbin's (1990) method for concept development. The following central concepts emerged from the focus groups with visiting nurses: "Missing contact in the field," "Consumption of time writing on forms," "Using the computer to help with the practice of home health nursing," and "Home nursing is a lifeline." These concepts, based on the commentaries by visiting nurses, help one to understand the problems encountered by visiting nurses in the delivery of home health care, identify ways to incorporate evolving technologies to enhance nursing practice, and consider approaches to computer skill acquisition. 15. Use of mobile phones, computers and internet among clients of an inner-city community psychiatric clinic. Science.gov (United States) Colder Carras, Michelle; Mojtabai, Ramin; Furr-Holden, C Debra; Eaton, William; Cullen, Bernadette A M 2014-03-01 Recent years have witnessed an expansion of Internet- and mobile-phone-based interventions for health promotion, yet few studies have focused on the use of technology by individuals with mental illness. This study examined the extent to which patients at an inner-city community psychiatry clinic had access to information and communications technology (ICT) and how they used those resources. Patients of an outpatient, inner-city community psychiatry program (N=189) completed a survey that included questions about demographics and ICT use which were adapted from an existing local population-based health survey (community sample, N=968). Frequencies of ICT use were assessed for the clinic sample and questions common to both the surveys completed by the clinic and community samples were compared using logistic regression. Among clinic cases, 105 (55.6%) reported owning or using a computer, 162 (85.7%) reported owning or using a mobile phone, and 112 (59.3%) reportedf using the Internet. Among those who used mobile phones, the majority reported using them daily; 42% of those who used the Internet reported using it several times per day. Differences in frequency of Internet use between samples were not significant, but clinic participants used the Internet more intensively to email, instant message, access health information, and use social media sites. A majority of patients in this community psychiatry clinic sample use ICT. Greater access to and use of the Internet by those with mental illness has important implications for the feasibility and impact of technology-based interventions. 16. Custody, care and country of origin: demographic and diagnostic admission statistics at an inner-city adult psychiatry unit. Science.gov (United States) Kelly, Brendan D; Emechebe, Afam; Anamdi, Chike; Duffy, Richard; Murphy, Niamh; Rock, Catherine 2015-01-01 Involuntary detention is a feature of psychiatric care in many countries. We previously reported an involuntary admission rate of 67.7 per 100,000 population per year in inner-city Dublin (January 2008-December 2010), which was higher than Ireland's national rate (38.5). We also found that the proportion of admissions that was involuntary was higher among individuals born outside Ireland (33.9%) compared to those from Ireland (12.0%), apparently owing to increased diagnoses of schizophrenia in the former group. In the present study (January 2011-June 2013) we again found that the proportion of admissions that was involuntary was higher among individuals from outside Ireland (32.5%) compared to individuals from Ireland (9.9%) (pIreland (206.1 voluntary admissions per 100,000 population per year; deprivation-adjusted rate: 158.5) compared to individuals from Ireland (775.1; deprivation-adjusted rate: 596.2). Overall, admission rates in our deprived, inner-city catchment area remain higher than national rates and this may be attributable to differential effects of Ireland's recent economic problems on different areas within Ireland. The relatively low rate of voluntary admission among individuals born outside Ireland may be attributable to different patterns of help-seeking which mental health services in Ireland need to take into account in future service-planning. Other jurisdictions could also usefully focus attention not just on rates on involuntary admission among individuals born elsewhere, but also rates of voluntary admission which may provide useful insights for service-planning and delivery. Copyright © 2015 Elsevier Ltd. All rights reserved. 17. A multimedia educational program that increases science achievement among inner-city non-Asian minority middle-school students. Science.gov (United States) Murray, Nancy G; Opuni, Kwame A; Reininger, Belinda; Sessions, Nathalie; Mowry, Melanie M; Hobbs, Mary 2009-06-01 To test the effectiveness of a middle school, multimedia health sciences educational program called HEADS UP in non-Asian-minority (Hispanic and African American), inner-city students. The program designers hope to increase the number of these students entering the health sciences pipeline. The program includes video role-model stories featuring minority scientists and students, hands-on activities, and teacher resources. Collaborators from The University of Texas Health Science Center at Houston, Spring Branch Independent School District, and the Health Museum developed the modules. From 2004 to 2007, the authors used a quasi-experimental, two-group pretest/posttest design to assess program effects on students' performance and interest in science, their science self-efficacy, their fear of science, and their science-related careers self-efficacy. An independent third party matched the intervention school to a comparison school by test scores, school demographics, and student demographics and then matched pairs of sixth-grade students (N = 428) by fifth-grade science scores, gender, ethnicity, and participation in the free or reduced lunch program. The authors collected data on these students for three years. At eighth grade (2007), the intervention school students scored significantly higher (F = 12.38, P science and reported higher interest in science (F = 11.08, P school pairs. Students in neither group reported an increase in their confidence to choose a science-related career, but students in one high-implementing teacher's class reported decreased fear of science. HEADS UP shows potential for improving inner-city, non-Asian-minority middle school students' performance and interest in science. 18. Prediction of Indoor Air Exposure from Outdoor Air Quality Using an Artificial Neural Network Model for Inner City Commercial Buildings Directory of Open Access Journals (Sweden) Avril Challoner 2015-12-01 Full Text Available NO2 and particulate matter are the air pollutants of most concern in Ireland, with possible links to the higher respiratory and cardiovascular mortality and morbidity rates found in the country compared to the rest of Europe. Currently, air quality limits in Europe only cover outdoor environments yet the quality of indoor air is an essential determinant of a person’s well-being, especially since the average person spends more than 90% of their time indoors. The modelling conducted in this research aims to provide a framework for epidemiological studies by the use of publically available data from fixed outdoor monitoring stations to predict indoor air quality more accurately. Predictions are made using two modelling techniques, the Personal-exposure Activity Location Model (PALM, to predict outdoor air quality at a particular building, and Artificial Neural Networks, to model the indoor/outdoor relationship of the building. This joint approach has been used to predict indoor air concentrations for three inner city commercial buildings in Dublin, where parallel indoor and outdoor diurnal monitoring had been carried out on site. This modelling methodology has been shown to provide reasonable predictions of average NO2 indoor air quality compared to the monitored data, but did not perform well in the prediction of indoor PM2.5 concentrations. Hence, this approach could be used to determine NO2 exposures more rigorously of those who work and/or live in the city centre, which can then be linked to potential health impacts. 19. Prediction of Indoor Air Exposure from Outdoor Air Quality Using an Artificial Neural Network Model for Inner City Commercial Buildings. Science.gov (United States) Challoner, Avril; Pilla, Francesco; Gill, Laurence 2015-12-01 NO₂ and particulate matter are the air pollutants of most concern in Ireland, with possible links to the higher respiratory and cardiovascular mortality and morbidity rates found in the country compared to the rest of Europe. Currently, air quality limits in Europe only cover outdoor environments yet the quality of indoor air is an essential determinant of a person's well-being, especially since the average person spends more than 90% of their time indoors. The modelling conducted in this research aims to provide a framework for epidemiological studies by the use of publically available data from fixed outdoor monitoring stations to predict indoor air quality more accurately. Predictions are made using two modelling techniques, the Personal-exposure Activity Location Model (PALM), to predict outdoor air quality at a particular building, and Artificial Neural Networks, to model the indoor/outdoor relationship of the building. This joint approach has been used to predict indoor air concentrations for three inner city commercial buildings in Dublin, where parallel indoor and outdoor diurnal monitoring had been carried out on site. This modelling methodology has been shown to provide reasonable predictions of average NO₂ indoor air quality compared to the monitored data, but did not perform well in the prediction of indoor PM2.5 concentrations. Hence, this approach could be used to determine NO₂ exposures more rigorously of those who work and/or live in the city centre, which can then be linked to potential health impacts. 20. "I Feel Suffocated:" Understandings of Climate Change in an Inner City Heat Island. Science.gov (United States) Singer, Merrill; Hasemann, Jose; Raynor, Abigail 2016-01-01 Global climate change is contributing to a range of adverse environmental and weather shifts, including more intense and more frequent heatwaves and an intensification of the urban heat island effect. These changes are known to produce a set of significant and differentially distributed health problems, with a particularly high burden among poor and marginalized populations. In this article, we report findings from a qualitative study of community knowledge, attitudes, health and other concerns, and behavioral responses regarding mounting urban temperatures and related environmental health issues among Latinos living in the city of Hartford, CT in northeast United States. Findings suggest the need for enhanced participation in knowledge dissemination and preparedness planning based on the coproduction of knowledge about climate change and community responses to it. The special role of anthropology in such efforts is highlighted. 1. The Effect of Text Materials with Relevant Language, Illustrations and Content Upon the Reading Achievement and Reading Preference (Attitude) of Black Primary and Intermediate Inner-City Students. Science.gov (United States) Grant, Gloria W. The purpose of this study was to examine the effect of text materials with relevant language, illustrations, and content upon the reading achievement and reading preference (attitude) of black primary and intermediate grade inner-city students. The subjects for the study were 330 black students enrolled in three schools in a large urban area. A… 2. Seeping Deficit Thinking Assumptions Maintain the Neoliberal Education Agenda: Exploring Three Conceptual Frameworks of Deficit Thinking in Inner-City Schools Science.gov (United States) Sharma, Manu 2018-01-01 This article draws awareness to the subtle and seeping "common sense" mentality of neoliberalism and deficit thinking assumptions about racially marginalized students in inner-city schools. From a literature review conducted on deficit thinking and deficit practices in schools, I developed three different frameworks for understanding the… 3. There Are No Children Here: The Case of an Inner-City School Addressing Issues Facing Children and Families Living in Poverty Science.gov (United States) Sallee, Mariel; Boske, Christa 2013-01-01 This case is based on real-life experiences of community school members within Horner School--an inner-city public school. Specifically, the case explores challenges faced by Cathleen, a 1st-year, White, female principal, who was hired by central office to "revamp a charter school" to promote a quality education for all children. The case raises… 4. Dating Violence Perpetration and/or Victimization and Associated Sexual Risk Behaviors among a Sample of Inner-City African American and Hispanic Adolescent Females Science.gov (United States) Alleyne-Green, Binta; Coleman-Cowger, Victoria H.; Henry, David B. 2012-01-01 The purpose of this study is to examine the prevalence of physical and psychological dating violence victimization and perpetration reported by inner-city African American and Hispanic adolescent girls as well as associated risky sexual behaviors among this population. Participants in this study were 10th- and 11th-grade female students from seven… 5. 'Hyped up': assemblages of alcohol, excitement and violence for outer-suburban young adults in the inner-city at night. Science.gov (United States) MacLean, Sarah; Moore, David 2014-05-01 Young adults from across greater Melbourne are drawn to the city centre night time economy (NTE). There is some evidence that young adults who live in outer-suburbs are involved in higher rates of weekend night time assaults than their inner-urban peers, both as perpetrators and as victims. Using the notion of 'assemblages', this article explores outer-suburban people's participation in the affectively charged spaces of inner-city entertainment precincts to show that trouble in the NTE cannot be attributed to alcohol and other drugs alone. We provide a narrative analysis of interviews conducted in 2012 with 60 young adult drinkers aged 18-24, half of whom lived in an inner-city area and half in outer-suburbs. More so for young adults from outer-suburbs than those who live closer to the city, going to the city is an event marked out as different from everyday life. Their sense of being 'hyped up' in the inner-city made different sets of practices possible, particularly in relation to drinking and being open to new engagements with friends and sexual partners. Participants also spoke, however, of discomfort, danger and fear. Violence was most likely to occur at points where people felt a dissonance between their heightened affective states and the spaces where they found themselves. In this analysis, outer-suburban young adults' positioning within the assemblages of the city centre NTE makes conflict and violence more likely for them. Efforts to improve NTE safety should maintain a focus on managing alcohol availability. Nonetheless additional strategies to decentralise the NTE, ensure better late night public transport to outer-suburbs or to support people to manage sudden affective shifts in NTE might also play a greater part in the overall effort. Copyright © 2014 Elsevier B.V. All rights reserved. 6. Alcohol use and sexual risk behaviour among men and women in inner-city Johannesburg, South Africa Directory of Open Access Journals (Sweden) Braimoh Bello 2017-07-01 Full Text Available Abstract Background Alcohol misuse is a key factor underlying the remarkable vulnerability to HIV infection among men and women in sub-Saharan Africa, especially within urban settings. Its effects, however, vary by type of drinking, population group and are modified by socio-cultural co-factors. Methods We interviewed a random sample of 1465 men living in single-sex hostels and 1008 women in adjacent informal settlements in inner-city, Johannesburg, South Africa. Being drunk in the past week was used as an indicator of heavy episodic drinking, and frequency of drinking and number of alcohol units/week used as measures of volume. Associations between dimensions of alcohol use (current drinking, volume of alcohol consumed and heavy episodic drinking patterns and sexual behaviours were assessed using multivariate logistic regression. Results Most participants were internal migrants from KwaZulu Natal province. About half of men were current drinkers, as were 13% of women. Of current male drinkers, 18% drank daily and 23% were drunk in the past week (women: 14% and 29% respectively. Among men, associations between heavy episodic drinking and sexual behaviour were especially pronounced. Compared with non-drinkers, episodic ones were 2.6 fold more likely to have transactional sex (95%CI = 1.7–4.1 and 2.2 fold more likely to have a concurrent partner (95%CI = 1.5–3.2. Alcohol use in men, regardless of measure, was strongly associated with having used physical force to have sex. Overall effects of alcohol on sexual behaviour were larger in women than men, and associations were detected between all alcohol measures in women, and concurrency, transactional sex and having been forced to have sex. Conclusions Alcohol use and sexual behaviours are strongly linked among male and female migrant populations in inner-city Johannesburg. More rigorous interventions at both local and macro level are needed to alleviate alcohol harms and mitigate the alcohol 7. From fear to resilience: adolescents' experiences of violence in inner-city Johannesburg, South Africa. Science.gov (United States) Scorgie, Fiona; Baron, Deborah; Stadler, Jonathan; Venables, Emilie; Brahmbhatt, Heena; Mmari, Kristin; Delany-Moretlwe, Sinead 2017-07-04 For adolescents growing up in poor urban South African settings, violence is often a part of daily life and has lasting effects on physical and mental health outcomes in adulthood. We conducted a qualitative study to document and understand the forms of interpersonal violence experienced by adolescents living in Hillbrow, Johannesburg. In this article, we explore how violence is experienced differently by adolescent boys and girls, how they conceptualise 'dangerous' and 'safe' spaces in their neighbourhood and what gaps exist in available services for youth in Hillbrow. The article draws on data collected in the formative phase of the 'Wellbeing of Adolescents in Vulnerable Environments' (WAVE) Study of challenges faced by adolescents (15-19 years) growing up in impoverished parts of five cities. This article reports on analysis using only data from the Johannesburg site. Using both purposive and snowball sampling to select participants, we conducted in-depth interviews (n = 20) and community mapping exercises with female (n = 19) and male (n = 20) adolescents living in Hillbrow, as well as key informant interviews with representatives of residential shelters, CBOs, and NGOs working with youth (n = 17). Transcripts were coded manually and analysed using an inductive thematic analysis approach. Both girls and boys reported high exposure to witnessing violence and crime. For girls, the threat of sexual harassment and violence was pervasive, while boys feared local gangs, the threat of physical violence, and being drawn into substance-abuse. Home was largely a safe haven for boys, whereas for girls it was often a space of sexual violence, abuse and neglect. Some adolescents developed coping mechanisms, such as actively seeking out community theatres, churches and other places of sanctuary from violence. Community-based services and shelters that support adolescents reported a lack of resources, overall instability and difficulties networking effectively 8. From fear to resilience: adolescents’ experiences of violence in inner-city Johannesburg, South Africa Directory of Open Access Journals (Sweden) Fiona Scorgie 2017-07-01 Full Text Available Abstract Background For adolescents growing up in poor urban South African settings, violence is often a part of daily life and has lasting effects on physical and mental health outcomes in adulthood. We conducted a qualitative study to document and understand the forms of interpersonal violence experienced by adolescents living in Hillbrow, Johannesburg. In this article, we explore how violence is experienced differently by adolescent boys and girls, how they conceptualise ‘dangerous’ and ‘safe’ spaces in their neighbourhood and what gaps exist in available services for youth in Hillbrow. Methods The article draws on data collected in the formative phase of the ‘Wellbeing of Adolescents in Vulnerable Environments’ (WAVE Study of challenges faced by adolescents (15–19 years growing up in impoverished parts of five cities. This article reports on analysis using only data from the Johannesburg site. Using both purposive and snowball sampling to select participants, we conducted in-depth interviews (n = 20 and community mapping exercises with female (n = 19 and male (n = 20 adolescents living in Hillbrow, as well as key informant interviews with representatives of residential shelters, CBOs, and NGOs working with youth (n = 17. Transcripts were coded manually and analysed using an inductive thematic analysis approach. Results Both girls and boys reported high exposure to witnessing violence and crime. For girls, the threat of sexual harassment and violence was pervasive, while boys feared local gangs, the threat of physical violence, and being drawn into substance-abuse. Home was largely a safe haven for boys, whereas for girls it was often a space of sexual violence, abuse and neglect. Some adolescents developed coping mechanisms, such as actively seeking out community theatres, churches and other places of sanctuary from violence. Community-based services and shelters that support adolescents reported a lack of resources 9. A social marketing campaign to promote low-fat milk consumption in an inner-city Latino community. Science.gov (United States) Wechsler, H; Wernick, S M 1992-01-01 The authors proposed the Lowfat Milk Campaign, a multifaceted social marketing campaign to promote the use of low-fat milk in the Washington Heights-Inwood neighborhood of New York City, a low-income, inner-city, Latino community. The campaign was designed for implementation by the Washington Heights-Inwood Health Heart Program, a community-based cardiovascular disease prevention agency. The first phase of the campaign began in November 1990. A followup phase for the period 1991-92 is in progress. The campaign focuses on a clear, relatively easily accomplished behavioral change, a switch by consumers of whole milk to low-fat milk, which may significantly reduce the fat consumption of persons in such a population, particularly children. The campaign strategy featured a mix of traditional health education methods, intensive local information media publicity, and innovative marketing techniques. In addition to increasing consumer demand for low-fat milk, the campaign successfully promoted institutional changes that are expected to facilitate healthy dietary choices in the future by members of the study population. Schools and other institutions that serve milk have been persuaded to begin offering low-fat milk in addition to, or instead of, whole milk. An essential component of campaign strategy was building support from key community organizations and leaders. Significant assistance was provided by the local school district, parents associations, churches, newspapers, radio stations, fraternal organizations, and a coalition of child care agencies. The campaign demonstrates a cost effective and culturally sensitive approach to promoting important cardiovascular health behavior changes by an underserved population. 10. Ecology of Leptospira interrogans in Norway rats (Rattus norvegicus in an inner-city neighborhood of Vancouver, Canada. Directory of Open Access Journals (Sweden) Chelsea G Himsworth Full Text Available Leptospira interrogans is a bacterial zoonosis with a worldwide distribution for which rats (Rattus spp. are the primary reservoir in urban settings. In order to assess, monitor, and mitigate the risk to humans, it is important to understand the ecology of this pathogen in rats. The objective of this study was to characterize the ecology of L. interrogans in Norway rats (Rattus norvegicus in an impoverished inner-city neighborhood of Vancouver, Canada.Trapping was performed in 43 city blocks, and one location within the adjacent port, over a 12 month period. Kidney samples were tested for the presence of L. interrogans using PCR and sequencing. A multivariable model was built to predict L. interrogans infection status in individual rats using season and morphometric data (e.g., weight, sex, maturity, condition, etc. as independent variables. Spatial analysis was undertaken to identify clusters of high and low L. interrogans prevalence. The prevalence of L. interrogans varied remarkably among blocks (0-66.7%, and spatial clusters of both high and low L. interrogans prevalence were identified. In the final cluster-controlled model, characteristics associated with L. interrogans-infection in rats included weight (OR = 1.14, 95% CI = 1.07-1.20, increased internal fat (OR = 2.12, 95% CI = 1.06-4.25, and number of bite wounds (OR = 1.20, 95% CI = 0.96-1.49.Because L. interrogans prevalence varied with weight, body fat, and bite wounds, this study suggests that social structure and interactions among rats may influence transmission. The prevalence and distribution of L. interrogans in rats was also highly variable even over a short geographic distance. These factors should be considered in future risk management efforts. 11. The relationship between distress tolerance and antisocial personality disorder among male inner-city treatment seeking substance users. Science.gov (United States) Daughters, Stacey B; Sargeant, Marsha N; Bornovalova, Marina A; Gratz, Kim L; Lejuez, C W 2008-10-01 There is currently limited research on the potential mechanisms underlying the development of antisocial personality disorder (ASPD). One such mechanism, distress tolerance (defined as an individual's behavioral persistence in the face of emotional distress) may underlie the development of ASPD and its associated behavioral difficulties. It was hypothesized that substance users with ASPD would evidence significantly lower levels of distress tolerance than substance users without ASPD. To test this relationship, we assessed 127 inner-city males receiving residential substance abuse treatment with two computerized laboratory measures of distress tolerance. The mean age of the sample was 40.1 years (SD = 9.8) and 88.2% were African American. As expected, multiple logistic regression analyses indicated that distress intolerance significantly predicted the presence of an ASPD diagnosis, above and beyond key covariates including substance use frequency and associated Axis I and II psychopathology. Findings suggest that distress tolerance may be a key factor in understanding the development of ASPD, setting the stage for future studies expanding on the nature of this relationship, as well as the development of appropriate interventions for this at-risk group. 12. Risk taking and refusal assertiveness in a longitudinal model of alcohol use among inner-city adolescents. Science.gov (United States) Epstein, J A; Griffin, K W; Botvin, G J 2001-09-01 Risk taking and refusal assertiveness have been shown to be important determinants of adolescent alcohol use. However, it remains unclear whether youth predisposed to risk taking would be less likely to assertively refuse. This study examined the relationships among risk taking, refusal assertiveness, and alcohol use in a sample of inner-city minority students (N = 1,459), using a cross-lagged longitudinal structural equation model. Data collectors administered the questionnaire to students following a standardized protocol during a 40-min class period. Based on the tested model, risk taking was more stable over time than refusal assertiveness. Furthermore, high risk takers reported less frequent subsequent refusal assertiveness, and less frequent refusal assertiveness predicted greater drinking. A predisposition toward risk taking appears to be an enduring characteristic that is associated with low refusal assertiveness and increased alcohol use. These findings suggest that alcohol prevention programs that emphasize refusal skills training may be less effective for high risk takers. But programs that focus on enhancing competence or reducing normative expectations for peer alcohol use might be more effective for high risk-taking youth. 13. Use of MP3 players to increase asthma knowledge in inner-city African-American adolescents. Science.gov (United States) Mosnaim, Giselle S; Cohen, Marc S; Rhoads, Christopher H; Rittner, Sarah Stuart; Powell, Lynda H 2008-01-01 Low-income African-American adolescents suffer a disproportionate burden of asthma morbidity. To evaluate the ability of our intervention, the Adolescents' Disease Empowerment and Persistency Technology (ADEPT) for asthma, to increase asthma knowledge in our target population. This was a 14-week (2-week run-in and 12-week treatment) randomized, double-blind, placebo-controlled pilot study in which 28 inner-city African-American adolescents with asthma, between 10 and 18 years of age, were randomized to receive (1) celebrity asthma messages (experimental group), or (2) general health messages (control group) between music tracks on an MP3 player. The asthma messages were recorded by famous athletes, musicians, and other celebrities popular among this group of teenagers. Asthma knowledge, assessed by the ZAP Asthma Knowledge instrament, was collected pre- and post-intervention. Mean improvement in ZAP score was significantly higher in the experimental group (8.1%, SD 7.2%) than the control group (0.4%, SD 7.2%) (p = 0.05). These findings suggest that this may be an innovative and promising new approach to improving asthma outcomes in this difficult-to-reach population. 14. Impact on and use of an inner-city London Infectious Diseases Department by international migrants: a questionnaire survey. Science.gov (United States) Cooke, Graham; Hargreaves, Sally; Natkunarajah, Jana; Sandhu, Gurjinder; Dhasmana, Devesh; Eliahoo, Joseph; Holmes, Alison; Friedland, Jon S 2007-07-20 The UK has witnessed a considerable increase in immigration in the past decade. Migrant may face barriers to accessing appropriate health care on arrival and the current focus on screening certain migrants for tuberculosis on arrival is considered inadequate. We assessed the implications for an inner-city London Infectious Diseases Department in a high migrant area. We administered an anonymous 20-point questionnaire survey to all admitted patients during a 6 week period. Questions related to sociodemographic characteristics and clinical presentation. Analysis was by migration status (UK born vs overseas born). 111 of 133 patients completed the survey (response rate 83.4%). 58 (52.2%) were born in the UK; 53 (47.7%) of the cohort were overseas born. Overseas-born were over-represented in comparison to Census data for this survey site (47.7% vs 33.6%; proportional difference 0.142 [95% CI 0.049-0.235]; p = 0.002): overseas born reported 33 different countries of birth, most (73.6%) of whom arrived in the UK pre-1975 and self-reported their nationality as British. A smaller number (26.4%) were new migrants to the UK (arrival and once settled through primary care services. A more organised and holistic approach to migrant health care is required. 15. The role of landscape spatial patterns on obesity in Hispanic children residing in inner-city neighborhoods. Science.gov (United States) Kim, Jun-Hyun; Lee, Chanam; Olvara, Norma E; Ellis, Christopher D 2014-11-01 Childhood obesity and its comorbidities have become major public health challenges in the US. While previous studies have investigated the roles of land uses and transportation infrastructure on obesity, limited research has examined the influence of landscape spatial patterns. The purpose of this study was to examine the association between landscape spatial patterns and obesity in Hispanic children. Participants included 61 fourth- and fifth-grade Hispanic children from inner-city neighborhoods in Houston, TX. BMI z-scores were computed based on objectively-measured height and weight from each child. Parental and child surveys provided sociodemographic and physical activity data. Landscape indices were used to measure the quality of landscape spatial patterns surrounding each child's home by utilizing Geographic Information Systems and remote sensing analyses using aerial photo images. After controlling for sociodemographic factors, in the half-mile airline buffer, more tree patches and well-connected landscape patterns were negatively correlated with their BMI z-scores. Furthermore, larger sizes of urban forests and tree patches were negatively associated with children's BMI z-scores in the half-mile network buffer assessment. This study suggests that urban greenery requires further attention in studies aimed at identifying environmental features that reduce childhood obesity. 16. Another sociology DEFF Research Database (Denmark) Carleheden, Mikael 1998-01-01 contributing dianostics of the social pathologies of the modern state. Such an approach can find inspiration in classical sociology, but it is also important to realize that, today, we are living in another modernity. A liberation from social technology must thus include a liberation from objectivistic methods.... 17. Syringe sociology. Science.gov (United States) Vitellone, Nicole 2015-06-01 In this article I consider the impact of social epistemologies for understanding the object of the syringe. My aim is to examine the process through which the syringe transforms from an injecting device to a tool of social and political inquiry. Paying particular attention to the uses of Foucault, Becker, Bourdieu, Freud and Latour in empirical studies of injecting heroin use, I examine the sociology of the syringe through the lens of habit and habitus, discourse and deviance, mourning and melancholia, attachment and agencement. In pursuing the theory behind the object my goal is to address a sociological object in the making. In so doing I show how the syringe has been significant for social research, social theory, and sociology. It is the difference the object makes that this article seeks to describe. In tracing the epistemology of the syringe I show how the object is important not just for knowledge of addiction but sociology itself. © London School of Economics and Political Science 2015. 18. Improving visit cycle time using patient flow analysis in a high-volume inner-city hospital-based ambulatory clinic serving minority New Yorkers. Science.gov (United States) Dhar, Sanjay; Michel, Raquel; Kanna, Balavenkatesh 2011-01-01 Patient waiting time and waiting room congestion are quality indicators that are related to efficiency of ambulatory care systems and patient satisfaction. Our main purpose was to test a program to decrease patient visit cycle time, while maintaining high-quality healthcare in a high-volume inner-city hospital-based clinic in New York City. Use of patient flow analysis and the creation of patient care teams proved useful in identifying areas for improvement, target, and measure effectiveness of interventions. The end result is reduced visit cycle time, improved provider team performance, and sustained patient care outcomes. © 2010 National Association for Healthcare Quality. 19. The moderating role of risk-taking tendency and refusal assertiveness on social influences in alcohol use among inner-city adolescents. Science.gov (United States) Epstein, Jennifer A; Botvin, Gilbert J 2002-07-01 Many etiological models of adolescent alcohol use concentrate on the main effects of risk and protective factors. This study examined the moderating influence of risk-taking tendency and refusal assertiveness on perceived friends' drinking as associated with alcohol use among inner-city adolescents. Participants (N = 2,400; 54% female) completed questionnaires that included measures of risk-taking tendency, refusal assertiveness, perceived friends' drinking and alcohol use (drinking frequency, drinking amount and drunkenness). Main effects for perceived friends' drinking, risk-taking tendency and refusal assertiveness were found for all three drinking measures, consistent with prior work. Furthermore, significant interactions were found between (1) risk-taking tendency and perceived friends' drinking and (2) refusal assertiveness and perceived friends' drinking. High risk-taking tendency and low refusal assertiveness increased the impact of perceived friends' drinking on alcohol use among inner-city adolescents. This suggests that these factors are important components in preventing alcohol use. 20. Vocal Music Therapy for Chronic Pain Management in Inner-City African Americans: A Mixed Methods Feasibility Study. Science.gov (United States) Bradt, Joke; Norris, Marisol; Shim, Minjung; Gracely, Edward J; Gerrity, Patricia 2016-01-01 To date, research on music for pain management has focused primarily on listening to prerecorded music for acute pain. Research is needed on the impact of active music therapy interventions on chronic pain management. The aim of this mixed methods research study was to determine feasibility and estimates of effect of vocal music therapy for chronic pain management. Fifty-five inner-city adults, predominantly African Americans, with chronic pain were randomized to an 8-week vocal music therapy treatment group or waitlist control group. Consent and attrition rates, treatment compliance, and instrument appropriateness/burden were tracked. Physical functioning (pain interference and general activities), self-efficacy, emotional functioning, pain intensity, pain coping, and participant perception of change were measured at baseline, 4, 8, and 12 weeks. Focus groups were conducted at the 12-week follow-up. The consent rate was 77%. The attrition rate was 27% at follow-up. We established acceptability of the intervention. Large effect sizes were obtained for self-efficacy at weeks 8 and 12; a moderate effect size was found for pain interference at week 8; no improvements were found for general activities and emotional functioning. Moderate effect sizes were obtained for pain intensity and small effect sizes for coping, albeit not statistically significant. Qualitative findings suggested that the treatment resulted in enhanced self-management, motivation, empowerment, a sense of belonging, and reduced isolation. This study suggests that vocal music therapy may be effective in building essential stepping-stones for effective chronic pain management, namely enhanced self-efficacy, motivation, empowerment, and social engagement. © the American Music Therapy Association 2016. All rights reserved. For permissions, please e-mail: [email protected]. 1. Widening access to cardiovascular healthcare: community screening among ethnic minorities in inner-city Britain – the Healthy Hearts Project Directory of Open Access Journals (Sweden) Tracey Inessa 2007-11-01 Full Text Available Abstract Background The burden of cardiovascular disease (CVD in Britain is concentrated in inner-city areas such as Sandwell, which is home to a diverse multi-ethnic population. Current guidance for CVD risk screening is not established, nor are there specific details for ethnic minorities. Given the disparity in equitable healthcare for these groups, we developed a 'tailored' and systematic approach to CVD risk screening within communities of the Sandwell locality. The key anticipated outcomes were the numbers of participants from various ethnic backgrounds attending the health screening events and the prevalence of known and undiagnosed CVD risk within ethnic groups. Methods Data was collected during 10 health screening events (September 2005 and July 2006, which included an assessment of raised blood pressure, overweight, hyperlipidaemia, impaired fasting glucose, smoking habit and the 10 year CVD risk score. Specific features of our approach included (i community involvement, (ii a clinician who could deliver immediate attention to adverse findings, and (iii the use of an interpreter. Results A total of 824 people from the Sandwell were included in this study (47% men, mean age 47.7 years from community groups such as the Gujarati Indian, Punjabi Indian, European Caucasian, Yemeni, Pakistani and Bangladeshi. A total of 470 (57% individuals were referred to their General Practitioner with a report of an increased CVD score – undetected high blood pressure in 120 (15%, undetected abnormal blood glucose in 70 (8%, undetected raised total cholesterol in 149 (18%, and CVD risk management review in 131 (16%. Conclusion Using this systematic and targeted approach, there was a clear demand for this service from people of various ethnic backgrounds, of whom, one in two needed review from primary or secondary healthcare. Further work is required to assess the accuracy and clinical benefits of this community health screening approach. 2. Impact on and use of health services by international migrants: questionnaire survey of inner city London A&E attenders Directory of Open Access Journals (Sweden) Eliahoo Joseph 2006-11-01 Full Text Available Abstract Background Changing immigration trends pose new challenges for the UK's open access health service and there is considerable speculation that migrants from resource-poor countries place a disproportionate burden on services. Data are needed to inform provision of services to migrant groups and to ensure their access to appropriate health care. We compared sociodemographic characteristics and impact of migrant groups and UK-born patients presenting to a hospital A&E/Walk-In Centre and prior use of community-based General Practitioner (GP services. Methods We administered an anonymous questionnaire survey of all presenting patients at an A&E/Walk-In Centre at an inner-city London hospital during a 1 month period. Questions related to nationality, immigration status, time in the UK, registration and use of GP services. We compared differences between groups using two-way tables by Chi-Square and Fisher's exact test. We used logistic regression modelling to quantify associations of explanatory variables and outcomes. Results 1611 of 3262 patients completed the survey (response rate 49.4%. 720 (44.7% were overseas born, representing 87 nationalities, of whom 532 (73.9% were new migrants to the UK (≤10 years. Overseas born were over-represented in comparison to local estimates (44.7% vs 33.6%; p Conclusion Recently arrived migrants are a diverse and substantial group, of whom migrants from refugee-generating countries and asylum seekers comprise only a minority group. Service reorganisation to ensure improved access to community-based GPs and delivery of more appropriate care may lessen their impact on acute services. 3. Impact on and use of health services by international migrants: questionnaire survey of inner city London A&E attenders Science.gov (United States) Hargreaves, Sally; Friedland, Jon S; Gothard, Philip; Saxena, Sonia; Millington, Hugh; Eliahoo, Joseph; Le Feuvre, Peter; Holmes, Alison 2006-01-01 Background Changing immigration trends pose new challenges for the UK's open access health service and there is considerable speculation that migrants from resource-poor countries place a disproportionate burden on services. Data are needed to inform provision of services to migrant groups and to ensure their access to appropriate health care. We compared sociodemographic characteristics and impact of migrant groups and UK-born patients presenting to a hospital A&E/Walk-In Centre and prior use of community-based General Practitioner (GP) services. Methods We administered an anonymous questionnaire survey of all presenting patients at an A&E/Walk-In Centre at an inner-city London hospital during a 1 month period. Questions related to nationality, immigration status, time in the UK, registration and use of GP services. We compared differences between groups using two-way tables by Chi-Square and Fisher's exact test. We used logistic regression modelling to quantify associations of explanatory variables and outcomes. Results 1611 of 3262 patients completed the survey (response rate 49.4%). 720 (44.7%) were overseas born, representing 87 nationalities, of whom 532 (73.9%) were new migrants to the UK (≤10 years). Overseas born were over-represented in comparison to local estimates (44.7% vs 33.6%; p immigration status' were: work permit (24.4%), EU citizens (21.5%), with only 21 (1.3%) political asylum seekers/refugees. 178 (11%) reported nationalities from refugee-generating countries (RGCs), eg, Somalia, who were less likely to speak English. Compared with RGCs, and after adjusting for age and sex, the Australians, New Zealanders, and South Africans (ANS group; OR 0.28 [95% CI 0.11 to 0.71]; p = 0.008) and the Other Migrant (OM) group comprising mainly Europeans (0.13 [0.06 to 0.30]; p = 0.000) were less likely to have GP registration and to have made prior contact with GPs, yet this did not affect mode of access to hospital services across groups nor delay access 4. Impact on and use of an inner-city London Infectious Diseases Department by international migrants: a questionnaire survey Science.gov (United States) Cooke, Graham; Hargreaves, Sally; Natkunarajah, Jana; Sandhu, Gurjinder; Dhasmana, Devesh; Eliahoo, Joseph; Holmes, Alison; Friedland, Jon S 2007-01-01 Background The UK has witnessed a considerable increase in immigration in the past decade. Migrant may face barriers to accessing appropriate health care on arrival and the current focus on screening certain migrants for tuberculosis on arrival is considered inadequate. We assessed the implications for an inner-city London Infectious Diseases Department in a high migrant area. Methods We administered an anonymous 20-point questionnaire survey to all admitted patients during a 6 week period. Questions related to sociodemographic characteristics and clinical presentation. Analysis was by migration status (UK born vs overseas born). Results 111 of 133 patients completed the survey (response rate 83.4%). 58 (52.2%) were born in the UK; 53 (47.7%) of the cohort were overseas born. Overseas-born were over-represented in comparison to Census data for this survey site (47.7% vs 33.6%; proportional difference 0.142 [95% CI 0.049–0.235]; p = 0.002): overseas born reported 33 different countries of birth, most (73.6%) of whom arrived in the UK pre-1975 and self-reported their nationality as British. A smaller number (26.4%) were new migrants to the UK (≤10 years), mostly refugees/asylum seekers. Overseas-born patients presented with a broad range and more severe spectrum of infections, differing from the UK-born population, resulting in two deaths in this group only. Presentation with a primary infection was associated with refugee/asylum status (n = 8; OR 6.35 [95% CI 1.28–31.50]; p = 0.023), being a new migrant (12; 10.62 [2.24–50.23]; p = 0.003), and being overseas born (31; 3.69 [1.67–8.18]; p = 0.001). Not having registered with a primary-care physician was associated with being overseas born, being a refugee/asylum seeker, being a new migrant, not having English as a first language, and being in the UK for ≤5 years. No significant differences were found between groups in terms of duration of illness prior to presentation or duration of hospitalisation (mean 5. Impact on and use of an inner-city London Infectious Diseases Department by international migrants: a questionnaire survey Directory of Open Access Journals (Sweden) Holmes Alison 2007-07-01 Full Text Available Abstract Background The UK has witnessed a considerable increase in immigration in the past decade. Migrant may face barriers to accessing appropriate health care on arrival and the current focus on screening certain migrants for tuberculosis on arrival is considered inadequate. We assessed the implications for an inner-city London Infectious Diseases Department in a high migrant area. Methods We administered an anonymous 20-point questionnaire survey to all admitted patients during a 6 week period. Questions related to sociodemographic characteristics and clinical presentation. Analysis was by migration status (UK born vs overseas born. Results 111 of 133 patients completed the survey (response rate 83.4%. 58 (52.2% were born in the UK; 53 (47.7% of the cohort were overseas born. Overseas-born were over-represented in comparison to Census data for this survey site (47.7% vs 33.6%; proportional difference 0.142 [95% CI 0.049–0.235]; p = 0.002: overseas born reported 33 different countries of birth, most (73.6% of whom arrived in the UK pre-1975 and self-reported their nationality as British. A smaller number (26.4% were new migrants to the UK (≤10 years, mostly refugees/asylum seekers. Overseas-born patients presented with a broad range and more severe spectrum of infections, differing from the UK-born population, resulting in two deaths in this group only. Presentation with a primary infection was associated with refugee/asylum status (n = 8; OR 6.35 [95% CI 1.28–31.50]; p = 0.023, being a new migrant (12; 10.62 [2.24–50.23]; p = 0.003, and being overseas born (31; 3.69 [1.67–8.18]; p = 0.001. Not having registered with a primary-care physician was associated with being overseas born, being a refugee/asylum seeker, being a new migrant, not having English as a first language, and being in the UK for ≤5 years. No significant differences were found between groups in terms of duration of illness prior to presentation or duration of 6. Impact on and use of health services by international migrants: questionnaire survey of inner city London A&E attenders. Science.gov (United States) Hargreaves, Sally; Friedland, Jon S; Gothard, Philip; Saxena, Sonia; Millington, Hugh; Eliahoo, Joseph; Le Feuvre, Peter; Holmes, Alison 2006-11-29 Changing immigration trends pose new challenges for the UK's open access health service and there is considerable speculation that migrants from resource-poor countries place a disproportionate burden on services. Data are needed to inform provision of services to migrant groups and to ensure their access to appropriate health care. We compared sociodemographic characteristics and impact of migrant groups and UK-born patients presenting to a hospital A&E/Walk-In Centre and prior use of community-based General Practitioner (GP) services. We administered an anonymous questionnaire survey of all presenting patients at an A&E/Walk-In Centre at an inner-city London hospital during a 1 month period. Questions related to nationality, immigration status, time in the UK, registration and use of GP services. We compared differences between groups using two-way tables by Chi-Square and Fisher's exact test. We used logistic regression modelling to quantify associations of explanatory variables and outcomes. 1611 of 3262 patients completed the survey (response rate 49.4%). 720 (44.7%) were overseas born, representing 87 nationalities, of whom 532 (73.9%) were new migrants to the UK (immigration status' were: work permit (24.4%), EU citizens (21.5%), with only 21 (1.3%) political asylum seekers/refugees. 178 (11%) reported nationalities from refugee-generating countries (RGCs), eg, Somalia, who were less likely to speak English. Compared with RGCs, and after adjusting for age and sex, the Australians, New Zealanders, and South Africans (ANS group; OR 0.28 [95% CI 0.11 to 0.71]; p = 0.008) and the Other Migrant (OM) group comprising mainly Europeans (0.13 [0.06 to 0.30]; p = 0.000) were less likely to have GP registration and to have made prior contact with GPs, yet this did not affect mode of access to hospital services across groups nor delay access to care. Recently arrived migrants are a diverse and substantial group, of whom migrants from refugee-generating countries and 7. Barriers to use of modern contraceptives among women in an inner city area of Osogbo metropolis, Osun State, Nigeria Directory of Open Access Journals (Sweden) Asekun–Olarinmoye EO 2013-10-01 Full Text Available EO Asekun-Olarinmoye,1 WO Adebimpe,1 JO Bamidele,2 OO Odu,2 IO Asekun-Olarinmoye,3 EO Ojofeitimi41Department of Community Medicine, Faculty of Clinical Sciences, Osun State University, Osogbo, Osun State, Nigeria; 2Department of Community Medicine, Faculty of Clinical Sciences, Ekiti State University, Ado-Ekiti, Ekiti State, Nigeria; 3Department of Community Health, School of Public and Allied Health, Babcock University, Ilishan-Remo, Ogun State, Nigeria; 4Department of Community Medicine, Faculty of Clinical Sciences, Ladoke Akintola University of Technology, Osogbo, Osun State, NigeriaObjectives: To determine the knowledge and attitudes on modern contraceptive use of women living in an inner city area of Osogbo.Materials and methods: Three hundred and fifty nine women of childbearing age were studied utilizing a community-based, descriptive, cross-sectional study design. A multistage random sampling technique was used in recruiting respondents to the study. A four-part questionnaire was applied dually, by interviewers and by respondents' self administration, and the data was analyzed using the SPSS software version 17.0.Results: The mean age of respondents was 28.6 ± 6.65 years. The majority (90.3% of respondents were aware of modern methods of family planning (FP, 76.0% claimed awareness of where to obtain FP services, and 74.9% knew of at least five methods. However, only 30.6% had ever used contraceptives, while only 13.1% were current users. The most frequently used method was the male condom. The commonly perceived barriers accounting for low use of FP methods were fear of perceived side effects (44.0%, ignorance (32.6%, misinformation (25.1%, superstition (22.0%, and culture (20.3%. Some reasons were proffered for respondents' nonuse of modern contraception. Predictors of use of modern contraceptives include the awareness of a place of FP service provision, respondents' approval of the use of contraceptives, higher education status, and 8. On sociological catastrophe analysis International Nuclear Information System (INIS) Clausen, L. 1974-01-01 The present paper deals with standard terms of sociological catastrophe theory hitherto existing, collective behaviour during the catastrophe, and consequences for the empiric catastrophe sociology. (RW) [de 9. Perceptions of barriers, facilitators and motivators related to use of prenatal care: A qualitative descriptive study of inner-city women in Winnipeg, Canada. Science.gov (United States) Heaman, Maureen I; Sword, Wendy; Elliott, Lawrence; Moffatt, Michael; Helewa, Michael E; Morris, Heather; Tjaden, Lynda; Gregory, Patricia; Cook, Catherine 2015-01-01 The objective of this qualitative descriptive study was to explore the perceptions of women living in inner-city Winnipeg, Canada, about barriers, facilitators, and motivators related to their use of prenatal care. Individual, semi-structured interviews were conducted in person with 26 pregnant or postpartum women living in inner-city neighborhoods with high rates of inadequate prenatal care. Interviews averaged 67 min in length. Recruitment of participants continued until data saturation was achieved. Inductive content analysis was used to identify themes and subthemes under four broad topics of interest (barriers, facilitators, motivators, and suggestions). Sword's socio-ecological model of health services use provided the theoretical framework for the research. This model conceptualizes service use as a product of two interacting systems: the personal and situational attributes of potential users and the characteristics of health services. Half of the women in our sample were single and half self-identified as Aboriginal. Participants discussed several personal and system-related barriers affecting use of prenatal care, such as problems with transportation and child care, lack of prenatal care providers, and inaccessible services. Facilitating factors included transportation assistance, convenient location of services, positive care provider qualities, and tangible rewards. Women were motivated to attend prenatal care to gain knowledge and skills and to have a healthy baby. Consistent with the theoretical framework, women's utilization of prenatal care was a product of two interacting systems, with several barriers related to personal and situational factors affecting women's lives, while other barriers were related to problems with service delivery and the broader healthcare system. Overcoming barriers to prenatal care and capitalizing on factors that motivate women to seek prenatal care despite difficult living circumstances may help improve use of prenatal 10. Identifying design considerations for a shared decision aid for use at the point of outpatient clinical care: An ethnographic study at an inner city clinic. Science.gov (United States) Hajizadeh, Negin; Perez Figueroa, Rafael E; Uhler, Lauren M; Chiou, Erin; Perchonok, Jennifer E; Montague, Enid 2013-03-06 Computerized decision aids could facilitate shared decision-making at the point of outpatient clinical care. The objective of this study was to investigate whether a computerized shared decision aid would be feasible to implement in an inner-city clinic by evaluating the current practices in shared decision-making, clinicians' use of computers, patient and clinicians' attitudes and beliefs toward computerized decision aids, and the influence of time on shared decision-making. Qualitative data analysis of observations and semi-structured interviews with patients and clinicians at an inner-city outpatient clinic. The findings provided an exploratory look at the prevalence of shared decision-making and attitudes about health information technology and decision aids. A prominent barrier to clinicians engaging in shared decision-making was a lack of perceived patient understanding of medical information. Some patients preferred their clinicians make recommendations for them rather than engage in formal shared decision-making. Health information technology was an integral part of the clinic visit and welcomed by most clinicians and patients. Some patients expressed the desire to engage with health information technology such as viewing their medical information on the computer screen with their clinicians. All participants were receptive to the idea of a decision aid integrated within the clinic visit although some clinicians were concerned about the accuracy of prognostic estimates for complex medical problems. We identified several important considerations for the design and implementation of a computerized decision aid including opportunities to: bridge clinician-patient communication about medical information while taking into account individual patients' decision-making preferences, complement expert clinician judgment with prognostic estimates, take advantage of patient waiting times, and make tasks involved during the clinic visit more efficient. These findings 11. Barriers, motivators and facilitators related to prenatal care utilization among inner-city women in Winnipeg, Canada: a case-control study. Science.gov (United States) Heaman, Maureen I; Moffatt, Michael; Elliott, Lawrence; Sword, Wendy; Helewa, Michael E; Morris, Heather; Gregory, Patricia; Tjaden, Lynda; Cook, Catherine 2014-07-15 The reasons why women do not obtain prenatal care even when it is available and accessible are complex. Despite Canada's universally funded health care system, use of prenatal care varies widely across neighborhoods in Winnipeg, Manitoba, with the highest rates of inadequate prenatal care found in eight inner-city neighborhoods. The purpose of this study was to identify barriers, motivators and facilitators related to use of prenatal care among women living in these inner-city neighborhoods. We conducted a case-control study with 202 cases (inadequate prenatal care) and 406 controls (adequate prenatal care), frequency matched 1:2 by neighborhood. Women were recruited during their postpartum hospital stay, and were interviewed using a structured questionnaire. Stratified analyses of barriers and motivators associated with inadequate prenatal care were conducted, and the Mantel-Haenszel common odds ratio (OR) was reported when the results were homogeneous across neighborhoods. Chi square analysis was used to test for differences in proportions of cases and controls reporting facilitators that would have helped them get more prenatal care. Of the 39 barriers assessed, 35 significantly increased the odds of inadequate prenatal care for inner-city women. Psychosocial issues that increased the likelihood of inadequate prenatal care included being under stress, having family problems, feeling depressed, "not thinking straight", and being worried that the baby would be apprehended by the child welfare agency. Structural barriers included not knowing where to get prenatal care, having a long wait to get an appointment, and having problems with child care or transportation. Attitudinal barriers included not planning or knowing about the pregnancy, thinking of having an abortion, and believing they did not need prenatal care. Of the 10 motivators assessed, four had a protective effect, such as the desire to learn how to protect one's health. Receiving incentives and getting 12. Barriers, motivators and facilitators related to prenatal care utilization among inner-city women in Winnipeg, Canada: a case–control study Science.gov (United States) 2014-01-01 Background The reasons why women do not obtain prenatal care even when it is available and accessible are complex. Despite Canada’s universally funded health care system, use of prenatal care varies widely across neighborhoods in Winnipeg, Manitoba, with the highest rates of inadequate prenatal care found in eight inner-city neighborhoods. The purpose of this study was to identify barriers, motivators and facilitators related to use of prenatal care among women living in these inner-city neighborhoods. Methods We conducted a case–control study with 202 cases (inadequate prenatal care) and 406 controls (adequate prenatal care), frequency matched 1:2 by neighborhood. Women were recruited during their postpartum hospital stay, and were interviewed using a structured questionnaire. Stratified analyses of barriers and motivators associated with inadequate prenatal care were conducted, and the Mantel-Haenszel common odds ratio (OR) was reported when the results were homogeneous across neighborhoods. Chi square analysis was used to test for differences in proportions of cases and controls reporting facilitators that would have helped them get more prenatal care. Results Of the 39 barriers assessed, 35 significantly increased the odds of inadequate prenatal care for inner-city women. Psychosocial issues that increased the likelihood of inadequate prenatal care included being under stress, having family problems, feeling depressed, “not thinking straight”, and being worried that the baby would be apprehended by the child welfare agency. Structural barriers included not knowing where to get prenatal care, having a long wait to get an appointment, and having problems with child care or transportation. Attitudinal barriers included not planning or knowing about the pregnancy, thinking of having an abortion, and believing they did not need prenatal care. Of the 10 motivators assessed, four had a protective effect, such as the desire to learn how to protect one 13. Measures of Biochemical Sociology Science.gov (United States) Snell, Joel; Marsh, Mitchell 2008-01-01 In a previous article, the authors introduced a new sub field in sociology that we labeled "biochemical sociology." We introduced the definition of a sociology that encompasses sociological measures, psychological measures, and biological indicators Snell & Marsh (2003). In this article, we want to demonstrate a research strategy that would assess… 14. How healthy is urban horticulture in high traffic areas? Trace metal concentrations in vegetable crops from plantings within inner city neighbourhoods in Berlin, Germany International Nuclear Information System (INIS) Säumel, Ina; Kotsyuk, Iryna; Hölscher, Marie; Lenkereit, Claudia; Weber, Frauke; Kowarik, Ingo 2012-01-01 Food production by urban dwellers is of growing importance in developing and developed countries. Urban horticulture is associated with health risks as crops in urban settings are generally exposed to higher levels of pollutants than those in rural areas. We determined the concentration of trace metals in the biomass of different horticultural crops grown in the inner city of Berlin, Germany, and analysed how the local setting shaped the concentration patterns. We revealed significant differences in trace metal concentrations depending on local traffic, crop species, planting style and building structures, but not on vegetable type. Higher overall traffic burden increased trace metal content in the biomass. The presence of buildings and large masses of vegetation as barriers between crops and roads reduced trace metal content in the biomass. Based on this we discuss consequences for urban horticulture, risk assessment, and planting and monitoring guidelines for cultivation and consumption of crops. - Highlights: ► Traffic-related pollutant deposition as important pathway for crop contamination. ► Heavy metal content often over EU standards for lead concentration in food crops. ► ‘Grow your own’ food in inner cities not always ‘healthier’ than supermarket products. ► No support for generalisations of crops as ‘risky high’ or ‘safe low’ accumulators. - Higher overall traffic burden increased, while the presence of buildings and large masses of vegetation as barriers between crops and roads reduced heavy metal content in crop biomass. 15. Safety and security in small-scale recovery housing for people with severe mental illness: an inner-city case study. Science.gov (United States) Whitley, Rob; Harris, Maxine; Drake, Robert E 2008-02-01 The authors examined the lived experience of residents with severe mental illness in a small-scale recovery-housing building in the inner city. They attempting to identify and understand factors that influenced adjustment and stability. Four focus groups with 17 residents and participant observation with residents, case managers, and supervisory staff were conducted longitudinally over a two-year period. Data were analyzed according to the tenets of qualitative content analysis. Safety and security was the most prominent issue raised by residents. Serious concerns about this issue could be divided into three categories: threats raised by the behavior of other residents (and their associates), threats raised by strangers, and threats related to loss of self-control. A related theme involved ongoing tension between residents' desire for communal connections and their conflicting desire for a bounded private life. Ongoing attention to the issue of safety and security should be a key component of recovery-oriented housing in inner-city residential areas. Further research may need to compare the experience of safety and security among residents living in recovery housing with the experience of those in independent scatter-site housing and traditional congregate housing. 16. Ensuring safe access to medication for palliative care while preventing prescription drug abuse: innovations for American inner cities, rural areas, and communities overwhelmed by addiction Directory of Open Access Journals (Sweden) Francoeur RB 2011-09-01 Full Text Available Richard B FrancoeurSchool of Social Work, Adelphi University, Garden City, NY, USA; Center for the Psychosocial Study of Health and Illness, Columbia University, New York, NY, USAAbstract: This article proposes and develops novel components of community-oriented programs for creating and affording access to safe medication dispensing centers in existing retail pharmacies and in permanent or travelling pharmacy clinics that are guarded by assigned or off-duty police officers. Pharmacists at these centers would work with police, medical providers, social workers, hospital administrators, and other professionals in: planning and overseeing the safe storage of controlled substance medications in off-site community safe-deposit boxes; strengthening communication and cooperation with the prescribing medical provider; assisting the prescribing medical provider in patient monitoring (checking the state prescription registry, providing pill counts and urine samples; expanding access to lower-cost, and in some cases, abuse-resistant formulations of controlled substance medications; improving transportation access for underserved patients and caregivers to obtain prescriptions; and integrating community agencies and social networks as resources for patient support and monitoring. Novel components of two related community-oriented programs, which may be hosted outside of safe medication dispensing centers, are also suggested and described: (1 developing medication purchasing cooperatives (ie, to help patients, families, and health institutions afford the costs of medications, including tamper- or abuse-resistant/deterrent drug formulations; and (2 expanding the role of inner-city methadone maintenance treatment programs in palliative care (ie, to provide additional patient monitoring from a second treatment team focusing on narcotics addiction, and potentially, to serve as an untapped source of opioid medication for pain that is less subject to abuse 17. Building Inner Resilience Science.gov (United States) Lantieri, Linda 2008-01-01 The capacity to be in control of one's thoughts, emotions, and physiology can form an internal safety net preparing children to face the challenges and opportunities of life. This is the goal of the Inner Resilience Program in the New York City Schools. Teachers in the Inner Resilience Program's intervention are exposed to calming and focusing… 18. Attendance at antenatal clinics in inner-city Johannesburg, South Africa and its associations with birth outcomes: analysis of data from birth registers at three facilities. Science.gov (United States) Gumede, Siphamandla; Black, Vivian; Naidoo, Nicolette; Chersich, Matthew F 2017-07-04 Antenatal care (ANC) clinics serve as key gateways to screening and treatment interventions that improve pregnancy outcomes, and are especially important for HIV-infected women. By disaggregating data on access to ANC, we aimed to identify variation in ANC attendance by level of care and across vulnerable groups in inner-city Johannesburg, and document the impact of non-attendance on birth outcomes. This record review of routine health service data involved manual extraction of 2 years of data from birth registers at a primary-, secondary- and tertiary-level facility within inner-city Johannesburg. Information was gathered on ANC attendance, HIV testing and status, pregnancy duration, delivery mode and birth outcomes. Women with an unknown attendance status were considered as not having attended clinic, but effects of this assumption were tested in sensitivity analyses. Multiple logistic regression was used to identify associations between ANC attendance and birth outcomes. Of 31,179 women who delivered, 88.7% (27,651) had attended ANC (95% CI = 88.3-89.0). Attendance was only 77% at primary care (5813/7543), compared to 89% at secondary (3661/4113) and 93% at tertiary level (18,177/19,523). Adolescents had lower ANC attendance than adults (85%, 1951/2295 versus 89%, 22,039/24,771). Only 37% of women not attending ANC had an HIV test (1308/3528), compared with 93% of ANC attenders (25,756/27,651). Caesarean section rates were considerably higher in women who had attended ANC (40%, 10,866/27,344) than non-attenders (13%, 422/3360). Compared to those who had attended ANC, non-attenders were 1.6 fold more likely to have a preterm delivery (95% CI adjusted odds ratio [aOR] = 1.4-1.8) and 1.4 fold more likely to have a stillbirth (aOR 95% CI = 1.1-1.9). Similar results were seen in analyses where missing data on ANC attendance was classified in different ways. Inner-city Johannesburg has an almost 5% lower ANC attendance rate than national levels. Attendance is 19. “Getting out of downtown”: a longitudinal study of how street-entrenched youth attempt to exit an inner city drug scene Directory of Open Access Journals (Sweden) Rod Knight 2017-05-01 Full Text Available Abstract Background Urban drug “scenes” have been identified as important risk environments that shape the health of street-entrenched youth. New knowledge is needed to inform policy and programing interventions to help reduce youths’ drug scene involvement and related health risks. The aim of this study was to identify how young people envisioned exiting a local, inner-city drug scene in Vancouver, Canada, as well as the individual, social and structural factors that shaped their experiences. Methods Between 2008 and 2016, we draw on 150 semi-structured interviews with 75 street-entrenched youth. We also draw on data generated through ethnographic fieldwork conducted with a subgroup of 25 of these youth between. Results Youth described that, in order to successfully exit Vancouver’s inner city drug scene, they would need to: (a secure legitimate employment and/or obtain education or occupational training; (b distance themselves – both physically and socially – from the urban drug scene; and (c reduce their drug consumption. As youth attempted to leave the scene, most experienced substantial social and structural barriers (e.g., cycling in and out of jail, the need to access services that are centralized within a place that they are trying to avoid, in addition to managing complex individual health issues (e.g., substance dependence. Factors that increased youth’s capacity to successfully exit the drug scene included access to various forms of social and cultural capital operating outside of the scene, including supportive networks of friends and/or family, as well as engagement with addiction treatment services (e.g., low-threshold access to methadone to support cessation or reduction of harmful forms of drug consumption. Conclusions Policies and programming interventions that can facilitate young people’s efforts to reduce engagement with Vancouver’s inner-city drug scene are critically needed, including meaningful 20. Attendance at antenatal clinics in inner-city Johannesburg, South Africa and its associations with birth outcomes: analysis of data from birth registers at three facilities Directory of Open Access Journals (Sweden) Siphamandla Gumede 2017-07-01 Full Text Available Abstract Background Antenatal care (ANC clinics serve as key gateways to screening and treatment interventions that improve pregnancy outcomes, and are especially important for HIV-infected women. By disaggregating data on access to ANC, we aimed to identify variation in ANC attendance by level of care and across vulnerable groups in inner-city Johannesburg, and document the impact of non-attendance on birth outcomes. Methods This record review of routine health service data involved manual extraction of 2 years of data from birth registers at a primary-, secondary- and tertiary-level facility within inner-city Johannesburg. Information was gathered on ANC attendance, HIV testing and status, pregnancy duration, delivery mode and birth outcomes. Women with an unknown attendance status were considered as not having attended clinic, but effects of this assumption were tested in sensitivity analyses. Multiple logistic regression was used to identify associations between ANC attendance and birth outcomes. Results Of 31,179 women who delivered, 88.7% (27,651 had attended ANC (95% CI = 88.3–89.0. Attendance was only 77% at primary care (5813/7543, compared to 89% at secondary (3661/4113 and 93% at tertiary level (18,177/19,523. Adolescents had lower ANC attendance than adults (85%, 1951/2295 versus 89%, 22,039/24,771. Only 37% of women not attending ANC had an HIV test (1308/3528, compared with 93% of ANC attenders (25,756/27,651. Caesarean section rates were considerably higher in women who had attended ANC (40%, 10,866/27,344 than non-attenders (13%, 422/3360. Compared to those who had attended ANC, non-attenders were 1.6 fold more likely to have a preterm delivery (95% CI adjusted odds ratio [aOR] = 1.4–1.8 and 1.4 fold more likely to have a stillbirth (aOR 95% CI = 1.1–1.9. Similar results were seen in analyses where missing data on ANC attendance was classified in different ways. Conclusion Inner-city Johannesburg has an almost 5 1. Racism, empire and sociology OpenAIRE Smith, Andrew 2017-01-01 Reviews of Gurminder K Bhambra, Connected Sociologies; Peo Hansen and Stefan Jonsson, Eurafrica: The Untold History of European Integration and Colonialism; Wulf D. Hund, Alana Lentin (eds) Racism and Sociology 2. Introduktion til klassisk sociologi DEFF Research Database (Denmark) Dupont, Søren Papiret introducerer til en række klassiske sociologer: Comte, Spencer, Weber, Durkheim og Habermas......Papiret introducerer til en række klassiske sociologer: Comte, Spencer, Weber, Durkheim og Habermas... 3. How healthy is urban horticulture in high traffic areas? Trace metal concentrations in vegetable crops from plantings within inner city neighbourhoods in Berlin, Germany. Science.gov (United States) Säumel, Ina; Kotsyuk, Iryna; Hölscher, Marie; Lenkereit, Claudia; Weber, Frauke; Kowarik, Ingo 2012-06-01 Food production by urban dwellers is of growing importance in developing and developed countries. Urban horticulture is associated with health risks as crops in urban settings are generally exposed to higher levels of pollutants than those in rural areas. We determined the concentration of trace metals in the biomass of different horticultural crops grown in the inner city of Berlin, Germany, and analysed how the local setting shaped the concentration patterns. We revealed significant differences in trace metal concentrations depending on local traffic, crop species, planting style and building structures, but not on vegetable type. Higher overall traffic burden increased trace metal content in the biomass. The presence of buildings and large masses of vegetation as barriers between crops and roads reduced trace metal content in the biomass. Based on this we discuss consequences for urban horticulture, risk assessment, and planting and monitoring guidelines for cultivation and consumption of crops. Copyright © 2012 Elsevier Ltd. All rights reserved. 4. The Effect of Social Problem Solving Skills in the Relationship between Traumatic Stress and Moral Disengagement among Inner-City African American High School Students Science.gov (United States) Coker, Kendell L.; Ikpe, Uduakobong N.; Brooks, Jeannie S.; Page, Brian; Sobell, Mark B. 2014-01-01 This study examined the relationship between traumatic stress, social problem solving, and moral disengagement among African American inner-city high school students. Participants consisted of 45 (25 males and 20 females) African American students enrolled in grades 10 through 12. Mediation was assessed by testing for the indirect effect using the confidence interval derived from 10,000 bootstrapped resamples. The results revealed that social problem-solving skills have an indirect effect on the relationship between traumatic stress and moral disengagement. The findings suggest that African American youth that are negatively impacted by trauma evidence deficits in their social problem solving skills and are likely to be at an increased risk to morally disengage. Implications for culturally sensitive and trauma-based intervention programs are also provided. PMID:25071874 5. Cumulative interpersonal traumas and social support as risk and resiliency factors in predicting PTSD and depression among inner-city women. Science.gov (United States) Schumm, Jeremiah A; Briggs-Phillips, Melissa; Hobfoll, Stevan E 2006-12-01 This study represents one of the largest examinations of how child abuse, adult rape, and social support impact inner-city women (N = 777). Using retrospective self-report, the effects of interpersonal trauma were shown to be cumulative such that women who experienced either child abuse or adult rape were 6 times more likely to have probable posttraumatic stress disorder (PTSD), whereas women who experienced both child abuse and rape were 17 times more likely to have probable PTSD. High social support predicted lower PTSD severity for women who experienced both child abuse and adult rape, but not for women who reported one or none of these traumas. Results suggest that social support, when left intact, might buffer the cumulative impact of child and adult interpersonal traumas. 6. Exposure to Rats and Rat-Associated Leptospira and Bartonella Species Among People Who Use Drugs in an Impoverished, Inner-City Neighborhood of Vancouver, Canada. Science.gov (United States) McVea, David A; Himsworth, Chelsea G; Patrick, David M; Lindsay, L Robbin; Kosoy, Michael; Kerr, Thomas 2018-02-01 Rat infestations are common, particularly in impoverished, inner-city neighborhoods. However, there has been little research into the nature and consequences of rat exposure in these neighborhoods, particularly in Canada. In this study, we sought to characterize exposure to rats and rat-associated Leptospira interrogans and Bartonella tribocorum, as well as risk factors associated with exposure, in residents (n = 202) of the Downtown Eastside (DTES) neighborhood of Vancouver, Canada. There was no evidence of exposure to rat-associated L. interrogans but 6/202 (3.0%) of participants were exposed to B. tribocorum, which is known to be circulating among DTES rats. We also found that frequent and close rat exposure was common among DTES residents, and that this exposure was particularly associated with injection drug use and outdoor income-generating activities (e.g., drug dealing). These risk factors may be good targets for interventions geared toward effectively reducing rat exposure. 7. The Effect of Social Problem Solving Skills in the Relationship between Traumatic Stress and Moral Disengagement among Inner-City African American High School Students. Science.gov (United States) Coker, Kendell L; Ikpe, Uduakobong N; Brooks, Jeannie S; Page, Brian; Sobell, Mark B 2014-06-01 This study examined the relationship between traumatic stress, social problem solving, and moral disengagement among African American inner-city high school students. Participants consisted of 45 (25 males and 20 females) African American students enrolled in grades 10 through 12. Mediation was assessed by testing for the indirect effect using the confidence interval derived from 10,000 bootstrapped resamples. The results revealed that social problem-solving skills have an indirect effect on the relationship between traumatic stress and moral disengagement. The findings suggest that African American youth that are negatively impacted by trauma evidence deficits in their social problem solving skills and are likely to be at an increased risk to morally disengage. Implications for culturally sensitive and trauma-based intervention programs are also provided. 8. Do men need empowering too? A systematic review of entrepreneurial education and microenterprise development on health disparities among inner-city black male youth. Science.gov (United States) Jennings, Larissa 2014-10-01 Economic strengthening through entrepreneurial and microenterprise development has been shown to mitigate poverty-based health disparities in developing countries. Yet, little is known regarding the impact of similar approaches on disadvantaged U.S. populations, particularly inner-city African-American male youth disproportionately affected by poverty, unemployment, and adverse health outcomes. A systematic literature review was conducted to guide programming and research in this area. Eligible studies were those published in English from 2003 to 2014 which evaluated an entrepreneurial and microenterprise initiative targeting inner-city youth, aged 15 to 24, and which did not exclude male participants. Peer-reviewed publications were identified from two electronic bibliographic databases. A manual search was conducted among web-based gray literature and registered trials not yet published. Among the 26 papers retrieved for review, six met the inclusion criteria and were retained for analysis. None of the 16 registered microenterprise trials were being conducted among disadvantaged populations in the U.S. The available literature suggests that entrepreneurial and microenterprise programs can positively impact youth's economic and psychosocial functioning and result in healthier decision-making. Young black men specifically benefited from increased autonomy, engagement, and risk avoidance. However, such programs are vastly underutilized among U.S. minority youth, and the current evidence is insufficiently descriptive or rigorous to draw definitive conclusions. Many programs described challenges in securing adequate resources, recruiting minority male youth, and sustaining community buy-in. There is an urgent need to increase implementation and evaluation efforts, using innovative and rigorous designs, to improve the low status of greater numbers of African-American male youth. 9. Clinical utility of the HEART score in patients admitted with chest pain to an inner-city hospital in the USA. Science.gov (United States) Patnaik, Soumya; Shah, Mahek; Alhamshari, Yaser; Ram, Pradhum; Puri, Ritika; Lu, Marvin; Balderia, Percy; Imms, John B; Maludum, Obiora; Figueredo, Vincent M 2017-06-01 Chest pain is one of the most common presentations to a hospital, and appropriate triaging of these patients can be challenging. The HEART score has been used for such purposes in some countries and only a few validation studies from the USA are available. We aim to determine the utility of the HEART score in patients presenting with chest pain to an inner-city hospital in the USA. We retrospectively screened 417 consecutive patients admitted with chest pain to the observation/telemetry units at Einstein Medical Center Philadelphia. After applying inclusion and exclusion criteria, 299 patients were included in the analysis. Patients were divided into low-risk (0-3) and intermediate-high (≥4)-risk HEART score groups. Baseline characteristics, thrombolysis in myocardial infarction score, need for revascularization during index hospitalization, and major adverse cardiovascular events (MACE) at 6 weeks and 12 months were recorded. There were 98 and 201 patients in the low-score group and intermediate-high-score group, respectively. Compared with the low-score group, patients in the intermediate-high-risk group had a higher incidence of revascularization during the index hospital stay (16.4 vs. 0%; P=0.001), longer hospital stay, higher MACE at 6 weeks (9.5 vs. 0%) and 12 months (20.4 vs. 3.1%), and higher cardiac readmissions. HEART score of at least 4 independently predicted MACE at 12 months (odds ratio 7.456, 95% confidence interval: 2.175-25.56; P=0.001) after adjusting for other risk factors in regression analysis. HEART score of at least 4 was predictive of worse outcomes in patients with chest pain in an inner-city USA hospital. If validated in multicenter prospective studies, the HEART score could potentially be useful in risk-stratifying patients presenting with chest pain in the USA and could impact clinical decision-making. 10. Sociology as a Vocation. Science.gov (United States) Lechner, Frank J. 1990-01-01 Examines the meaning of practicing sociology, claiming to "commit a social science" still makes sense. Accepts Max Weber's arguments that sociology clarifies human affairs and is oriented to certain virtues. Suggests, however, that sociology is a passion as well as a profession, something Weber recognized but did not elaborate. (NL) 11. Strategies employed by inner-city activists to reduce alcohol-related problems and advance social justice. Science.gov (United States) Drabble, Laurie; Herd, Denise 2014-01-01 This study explored strategies employed by activists engaged in efforts to change policies and laws related to selling and promoting alcoholic beverages based on in-depth interviews with 184 social activists in seven U.S. major cities. Nine strategies aimed at improving local conditions and influencing policy were described by activists across regional contexts. Grassroots mobilization was central to all other strategies, which included the creation or enforcement of laws, meeting with elected officials, media advocacy, working with police/law enforcement, education and training, direct action, changing community norms, and negotiating with store owners. 12. Summertime heat island intensities in three high-rise housing quarters in inner-city Shanghai China: Building layout, density and greenery Energy Technology Data Exchange (ETDEWEB) Yang, Feng; Lau, Stephen S.Y. [Department of Architecture, The University of Hong Kong, Pokfulam Road, Hong Kong SAR (China); Qian, Feng [College of Architecture and Urban Planning (CAUP), Tongji University, 1239 Siping Road, Shanghai, 200092 (China) 2010-01-15 Shanghai as the largest city in China has been suffering from the ever-worsening thermal environment due to the explosive urbanization rate. As an indication of urbanization impact, urban heat islands (UHI) can give rise to a variety of problems. This paper reports the results of an empirical study on the summertime UHI patterns in three high-rise residential quarters in the inner-city Shanghai. Site-means of UHI intensity are compared; case studies are carried out on strategically located measurement points; and regression analysis is followed to examine the significance of the on-site design variables in relation to UHI intensity. It is found that site characteristics in plot layout, density and greenery have different impacts on UHI-day and UHI-night patterns. Day-time UHI is closely related to site shading factor. Total site factor (TSF) as an integrated measure on solar admittance shows a higher explanatory power in UHI-day than sky view factor (SVF) does under a partially cloudy sky condition. Night-time UHI cannot be statistically well explained by the on-site variables in use, indicating influences from anthropogenic heat and other sources. Evaporative cooling by vegetation plays a more important role at night than it does at day. Considered diurnally, the semi-enclosed plot layout with a fairly high density and tree cover has the best outdoor thermal condition. Design implication based on the findings, with consideration on other important environmental design issues, is briefly discussed. (author) 13. The Impact of Course Delivery Systems on Student Achievement and Sense of Community: A Comparison of Learning Community versus Stand-Alone Classroom Settings in an Open-Enrollment Inner City Public Community College Science.gov (United States) Bandyopadhyay, Pamela 2010-01-01 This study examined the effects of two types of course delivery systems (learning community classroom environments versus stand-alone classroom environments) on the achievement of students who were simultaneously enrolled in remedial and college-level social science courses at an inner city open-enrollment public community college. This study was… 14. Inner-city green space and its association with body mass index and prevalent type 2 diabetes: a cross-sectional study in an urban German city. Science.gov (United States) Müller, Grit; Harhoff, Roland; Rahe, Corinna; Berger, Klaus 2018-01-21 The accessibility of green space is an important aspect of the urban residential environment and has been found to be beneficial for health and well-being. This study investigates the association between different indicators of green space and the outcomes body mass index (BMI) and prevalent type 2 diabetes in an urban population. Population-based cross-sectional study. Dortmund, a city located in the industrial Ruhr area in Western Germany. 1312 participants aged 25-74 years from the Dortmund Health Study. The participants' addresses were geocoded and shapefiles of statistical districts, road network and land use, as well as data on neighbourhood characteristics were obtained at baseline. Three indicators of green space were constructed using geographical information systems: proportion of green space, recreation location quotient (RLQ) weighted by population and distance to the next park or forest. Multilevel linear and logistic regression analyses on the association of green space with BMI and type 2 diabetes were performed, adjusted by individual-level characteristics and neighbourhood unemployment rate. The multilevel regression analyses showed no association between green space and BMI. In contrast, the three indicators of green space were significantly associated with type 2 diabetes. Residents of neighbourhoods with a low RLQ had a 2.44 (95% CI 1.01 to 5.93) times higher odds to have type 2 diabetes compared with residents of high RLQ neighbourhoods. Likewise, residing more than 0.8 km away from the nearest park or forest increased the odds of type 2 diabetes (OR 1.71, 95% CI 1.05 to 2.77). This study indicates that green space and its spatial accessibility might play a role in the development of type 2 diabetes. Further research is needed to clarify this association. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted. 15. The material, moral, and affective worlds of dealing and crime among young men entrenched in an inner city drug scene. Science.gov (United States) Fast, Danya; Shoveller, Jean; Kerr, Thomas 2017-06-01 A large body of previous research has elucidated how involvement in drug dealing and crime among marginalized urban youth who use drugs is shaped by the imperatives of addiction and survival in the context of poverty. However, a growing body of research has examined how youth's involvement in these activities is shaped by more expansive desires and moralities. In this paper, we examine the material, moral, and affective worlds of loosely gang affiliated, street level dealing and crime among one group of young men in Vancouver, Canada. Drawing on longitudinal interviews with 44 young men from 2008 to 2016, and ethnographic fieldwork with a group of approximately 15 of those young men over the same time period, we argue that for these youth, dealing and crime were not solely about economic survival, or even the accrual of highly meaningful forms of "street capital" in the margins. Rather, as "regimes of living," dealing and crime also opened up new value systems, moral logics, and affects in relation to the tremendous risks, potential rewards, and crushing boredom of life in the margins. These activities were also understood as a way into deeply desired forms of social spatial belonging in the city, which had previously only been imagined. However, across time dealing and crime "embedded" young men in cycles of incarceration, destitution, addictions, and mental health crises that ultimately reinforced their exclusion-from legal employment, but also within the world of crime. The findings of this study underscore the importance of adopting a life course perspective in order to meaningfully address the harms associated with involvement in dealing and crime among youth in our setting. Copyright © 2017 Elsevier B.V. All rights reserved. 16. Relationship between pulmonary function and indoor air pollution from coal combustion among adult residents in an inner-city area of southwest China Science.gov (United States) Jie, Y.; Houjin, H.; Xun, M.; Kebin, L.; Xuesong, Y.; Jie, X. 2014-01-01 Few studies evaluate the amount of particulate matter less than 2.5 mm in diameter (PM2.5) in relation to a change in lung function among adults in a population. The aim of this study was to assess the association of coal as a domestic energy source to pulmonary function in an adult population in inner-city areas of Zunyi city in China where coal use is common. In a cross-sectional study of 104 households, pulmonary function measurements were assessed and compared in 110 coal users and 121 non-coal users (≥18 years old) who were all nonsmokers. Several sociodemographic factors were assessed by questionnaire, and ventilatory function measurements including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), the FEV1/FVC ratio, and peak expiratory flow rate (PEFR) were compared between the 2 groups. The amount of PM2.5 was also measured in all residences. There was a significant increase in the relative concentration of PM2.5 in the indoor kitchens and living rooms of the coal-exposed group compared to the non-coal-exposed group. In multivariate analysis, current exposure to coal smoke was associated with a 31.7% decrease in FVC, a 42.0% decrease in FEV1, a 7.46% decrease in the FEV1/FVC ratio, and a 23.1% decrease in PEFR in adult residents. The slope of lung function decrease for Chinese adults is approximately a 2-L decrease in FVC, a 3-L decrease in FEV1, and an 8 L/s decrease in PEFR per count per minute of PM2.5 exposure. These results demonstrate the harmful effects of indoor air pollution from coal smoke on the lung function of adult residents and emphasize the need for public health efforts to decrease exposure to coal smoke. PMID:25296361 17. Re-bordering spaces of trauma: auto-ethnographic reflections on the immigrant and refugee experience in an inner-city high school in Toronto Science.gov (United States) Feuerverger, Grace 2011-08-01 The objective of this research study is to offer a glimpse into the lives of some newly-arrived students of different racial, linguistic and religious backgrounds as they confront the process of immigration and therefore personal and social displacement within the context of a Toronto inner-city high school. These students carry with them hidden but enduring scars that influence all aspects of their educational lives. In many cases their experience is steeped in trauma. Using auto-ethnographic methodology, this research is devoted to giving voice to these students who inhabit a space filled with suffering and loss but also resilience and cautious hope. If we really care about these vulnerable students in our classrooms, we must rethink and reshape our understanding of teaching and learning that is more fundamentally linked to the lived experiences of students coming from places of war and other oppressions. These issues are crucial for the future of nation-building and citizenship education in pluralistic Western societies such as Canada, both in and out of school. 18. A multilingual and multimodal approach to literacy teaching and learning in urban education: a collaborative inquiry project in an inner city elementary school. Science.gov (United States) Ntelioglou, Burcu Yaman; Fannin, Jennifer; Montanera, Mike; Cummins, Jim 2014-01-01 This paper presents findings from a collaborative inquiry project that explored teaching approaches that highlight the significance of multilingualism, multimodality, and multiliteracies in classrooms with high numbers of English language learners (ELLs). The research took place in an inner city elementary school with a large population of recently arrived and Canadian-born linguistically and culturally diverse students from Gambian, Indian, Mexican, Sri Lankan, Tibetan and Vietnamese backgrounds, as well as a recent wave of Roma students from Hungary. A high number of these students were from families with low-SES. The collaboration between two Grade 3 teachers and university-based researchers sought to create instructional approaches that would support students' academic engagement and literacy learning. In this paper, we described one of the projects that took place in this class, exploring how a descriptive writing unit could be implemented in a way that connected with students' lives and enabled them to use their home languages, through the creation of multiple texts, using creative writing, digital technologies, and drama pedagogy. This kind of multilingual and multimodal classroom practice changed the classroom dynamics and allowed the students access to identity positions of expertise, increasing their literacy investment, literacy engagement and learning. 19. The nutritional status of women in the first trimester of pregnancy attending an inner-city antenatal department in the UK. Science.gov (United States) Rees, Gail; Brooke, Zoe; Doyle, Wendy; Costeloe, Kate 2005-09-01 We have previously found high rates of poor iron and folate status in women who had delivered a low birthweight baby (LBW) in an ethnically diverse inner-city area of the UK. However, little was known of the nutritional status in the local general obstetric population. We therefore investigated biochemical measures of nutritional status in the first trimester of the first pregnancy. Routine blood samples collected at the antenatal booking clinic were analysed for haemoglobin (Hb), serum ferritin, red cell folate (RCF) (n = 100) and erythrocyte transketolase activation coefficient (ETKAC) for thiamin status (n = 90). We found 9% of women in our sample had a low Hb level, 10% had a low serum ferritin and only one had a low RCF. This is a substantially lower number of women with biochemical deficiencies than we found previously in women three months after delivering a LBW baby. However, 34% had low thiamin status. Thiamin status was negatively correlated with gestational age at birth (r = -0.407, p nutritional status were observed between ethnic and socio-economic groups. Hb levels differed between ethnic (p = 0.001) and socio-economic groups (p = 0.02), with Africans and women in manual occupations/unwaged having the lowest Hb levels. RCF levels also differed between groups (p nutrition particularly in ethnic minorities and low income groups who are most at risk of adverse birth outcomes such as LBW. 20. A multilingual and multimodal approach to literacy teaching and learning in urban education: a collaborative inquiry project in an urban inner city elementary school Directory of Open Access Journals (Sweden) Burcu eYaman Ntelioglou 2014-06-01 Full Text Available This paper presents findings from a collaborative inquiry project that explored teaching approaches that highlight the significance of multilingualism, multimodality and multiliteracies in classrooms with high numbers of English language learners (ELLs. The research took place in an inner city elementary school with a large population of recently arrived and Canadian-born linguistically and culturally diverse students from Gambian, Indian, Mexican, Sri Lankan, Tibetan and Vietnamese backgrounds, as well as a recent wave of Roma students from Hungary. A high number of these students were from families with low-SES. The collaboration between two Grade 3 teachers and university-based researchers sought to create instructional approaches that would support students’ academic engagement and literacy learning. In this paper, we described one of the projects that took place in this class, exploring how a descriptive writing unit could be implemented in a way that connected with students’ lives and enabled them to use their home languages, through the creation of multiple texts, using creative writing, digital technologies and drama pedagogy. This kind of multilingual and multimodal classroom practice changed the classroom dynamics and allowed the students access to identity positions of expertise, increasing their literacy investment, literacy engagement and learning. 1. Bringing the immigrant back into the sociology of taste. Science.gov (United States) Ray, Krishnendu 2017-12-01 The sociology of food consumption has emerged as a robust field with rich empirical material and engaged theorization about taste, omnivorousness, distinction, and practice theory. Nevertheless, there are continuing empirical and conceptual lacunae. Although transnational and rural-to-urban migrants play a crucial role in food businesses in many global cities, they are mostly unaccounted for in the sociology of taste. Taking the American case, in particular based on data from New York City, this article provides reasons for that gap and shows what might be gained if migrants were accounted for in the urban sociology of taste. Copyright © 2016 Elsevier Ltd. All rights reserved. 2. Sociology of Sport. Science.gov (United States) Greendorfer, Susan L. 1985-01-01 The author describes the issues which created the schism between physical education and sociology. If the subdiscipline of sports sociology is to survive, these misunderstandings must be erased. Current investigations of relevant topics are of interest to both physical educators and coaches and could begin to bridge the gap. (MT) 3. Sociology through Photography Science.gov (United States) Hyde, Katherine 2015-01-01 This chapter describes how photography can inspire and cultivate sociological mindfulness. One set of assignments uses self-portraiture to highlight the complexity of visual representations of social identity. Another uses photography to guide sociological inquiry. Both sets of assignments draw on the Literacy Through Photography methodology,… 4. Practicing Sociological Imagination through Writing Sociological Autobiography Science.gov (United States) Kebede, Alem 2009-01-01 Sociological imagination is a quality of mind that cannot be adopted by simply teaching students its discursive assumptions. Rather, it is a disposition, in competition with other forms of sensibility, which can be acquired only when it is practiced. Adhering to this important pedagogical assumption, students were assigned to write their… 5. The mental health impact of 9/11 on inner-city high school students 20 miles north of Ground Zero. Science.gov (United States) Calderoni, Michele E; Alderman, Elizabeth M; Silver, Ellen J; Bauman, Laurie J 2006-07-01 significantly associated with PTSD symptom cluster. We found a rate of PTSD in Bronx students after 9/11 that was much higher than other large studies of PTSD in adolescents done before 9/11. Adolescents living in inner cities with high poverty and violence rates may be at high risk for PTSD after a terrorist attack. Students who still felt vulnerable and less safe eight months later and those with prior mental health treatment were four times more likely to have PTSD than those without such characteristics, highlighting the influence of personality and mental health on development of PTSD after a traumatic event. 6. Relationship between pulmonary function and indoor air pollution from coal combustion among adult residents in an inner-city area of southwest China Energy Technology Data Exchange (ETDEWEB) Jie, Y.; Houjin, H. [Zunyi Medical University, School of Public Health, Zunyi, Guizhou (China); Xun, M. [Affiliated Hospital of Zunyi Medical University, Department of Medicine Laboratory, Zunyi (China); Kebin, L.; Xuesong, Y.; Jie, X. [Zunyi Medical University, School of Public Health, Zunyi, Guizhou (China) 2014-09-23 Few studies evaluate the amount of particulate matter less than 2.5 mm in diameter (PM{sub 2.5}) in relation to a change in lung function among adults in a population. The aim of this study was to assess the association of coal as a domestic energy source to pulmonary function in an adult population in inner-city areas of Zunyi city in China where coal use is common. In a cross-sectional study of 104 households, pulmonary function measurements were assessed and compared in 110 coal users and 121 non-coal users (≥18 years old) who were all nonsmokers. Several sociodemographic factors were assessed by questionnaire, and ventilatory function measurements including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV{sub 1}), the FEV{sub 1}/FVC ratio, and peak expiratory flow rate (PEFR) were compared between the 2 groups. The amount of PM{sub 2.5} was also measured in all residences. There was a significant increase in the relative concentration of PM{sub 2.5} in the indoor kitchens and living rooms of the coal-exposed group compared to the non-coal-exposed group. In multivariate analysis, current exposure to coal smoke was associated with a 31.7% decrease in FVC, a 42.0% decrease in FEV{sub 1}, a 7.46% decrease in the FEV{sub 1}/FVC ratio, and a 23.1% decrease in PEFR in adult residents. The slope of lung function decrease for Chinese adults is approximately a 2-L decrease in FVC, a 3-L decrease in FEV{sub 1}, and an 8 L/s decrease in PEFR per count per minute of PM{sub 2.5} exposure. These results demonstrate the harmful effects of indoor air pollution from coal smoke on the lung function of adult residents and emphasize the need for public health efforts to decrease exposure to coal smoke. 7. Superconductors for the medium-voltage grid. A superconducting power cable running through the inner city of Essen passes a two-year field test; Supraleiter fuer das Mittelspannungsnetz. Ein supraleitendes Stromkabel quer durch die Essener Innenstadt besteht zweijaehrigen Feldtest Energy Technology Data Exchange (ETDEWEB) Meyer, Franz 2017-04-01 Scientists are testing the longest high-temperature superconducting cable in the world under real conditions in Essen. One kilometre long, it connects two substations in the inner city. It replaces a conventional 110 kV line and renders one substation in the inner city obsolete. After two years of testing, it has passed the field test. It could be a blueprint for the future power supply system in urban areas. [German] Wissenschaftler testen in Essen das laengste Hochtemperatur-Supraleiterkabel der Welt unter realen Bedingungen. Mit einer Laenge von einem Kilometer verbindet es zwei Umspannstationen quer durch die Innenstadt. Es ersetzt eine konventionelle 110-kV-Leitung und macht eine Umspannanlage im Stadtzentrum ueberfluessig. In einer zweijaehrigen Erprobung hat es den Praxistest bestanden. Es koennte eine Blaupause fuer die kuenftige Stromversorgung in Ballungsraeumen sein. 8. Ensuring safe access to medication for palliative care while preventing prescription drug abuse: innovations for American inner cities, rural areas, and communities overwhelmed by addiction. Science.gov (United States) Francoeur, Richard B 2011-01-01 This article proposes and develops novel components of community-oriented programs for creating and affording access to safe medication dispensing centers in existing retail pharmacies and in permanent or travelling pharmacy clinics that are guarded by assigned or off-duty police officers. Pharmacists at these centers would work with police, medical providers, social workers, hospital administrators, and other professionals in: planning and overseeing the safe storage of controlled substance medications in off-site community safe-deposit boxes; strengthening communication and cooperation with the prescribing medical provider; assisting the prescribing medical provider in patient monitoring (checking the state prescription registry, providing pill counts and urine samples); expanding access to lower-cost, and in some cases, abuse-resistant formulations of controlled substance medications; improving transportation access for underserved patients and caregivers to obtain prescriptions; and integrating community agencies and social networks as resources for patient support and monitoring. Novel components of two related community-oriented programs, which may be hosted outside of safe medication dispensing centers, are also suggested and described: (1) developing medication purchasing cooperatives (ie, to help patients, families, and health institutions afford the costs of medications, including tamper-or abuse-resistant/deterrent drug formulations); and (2) expanding the role of inner-city methadone maintenance treatment programs in palliative care (ie, to provide additional patient monitoring from a second treatment team focusing on narcotics addiction, and potentially, to serve as an untapped source of opioid medication for pain that is less subject to abuse, misuse, or diversion). 9. Naloxone and the Inner City Youth Experience (NICYE): a community-based participatory research study examining young people's perceptions of the BC take home naloxone program. Science.gov (United States) Mitchell, Keren; Durante, S Elise; Pellatt, Katrina; Richardson, Chris G; Mathias, Steve; Buxton, Jane A 2017-06-07 Take home naloxone (THN) programs reduce mortality by training bystanders to respond to opioid overdoses. Clinical observation by the health care team at the Inner City Youth (ICY) program indicated that young adults appeared to enthusiastically participate in the THN program and developed improved relationships with staff after THN training. However, we found a dearth of literature exploring the experiences of young adults with THN programs. This study set out to address this gap and identify suggestions from the young adults for program improvement. The primary research question was "How do street-involved young people experience the THN Program in Vancouver, BC?" The study was undertaken at the ICY Program. Two peer researchers with lived experience of THN were recruited from ICY and were involved in all phases of the study. The peer researchers and a graduate student facilitated two focus groups and five individual interviews with ICY program participants using a semi-structured interview guide. Audio recordings were transcribed verbatim. The cut-up-and-put-in-folders approach was used to identify emerging themes. The themes that emerged were perceptions of risk, altruism, strengthening relationship with staff, access to training, empowerment, and confidence in ability to respond, and suggestions for youth-friendly training. These themes were then situated within the framework of the health belief model to provide additional context. Participants viewed themselves as vulnerable to overdose and spoke of the importance of expanding access to THN training. Following training, participants reported an increase in internal locus of control, an improved sense of safety among the community of people who use drugs, improved self-esteem, and strengthened relationships with ICY staff. Overall, participants found THN training engaging, which appeared to enhance participation in other ICY programming. Young people perceived THN training as a positive experience that 10. Mobile sociology. 2000. Science.gov (United States) Urry, John 2010-01-01 This article seeks to develop a manifesto for a sociology concerned with the diverse mobilities of peoples, objects, images, information, and wastes; and of the complex interdependencies between, and social consequences of, such diverse mobilities. A number of key concepts relevant for such a sociology are elaborated: 'gamekeeping', networks, fluids, scapes, flows, complexity and iteration. The article concludes by suggesting that a 'global civil society' might constitute the social base of a sociology of mobilities as we move into the twenty-first century. 11. Sociology Back to the Publics NARCIS (Netherlands) Ossewaarde, Marinus R.R. 2007-01-01 This article is a reading of the new sociology' that is mainly identified with the works of C. Wright Mills and Alvin Gouldner. Its main argument is that during the past 40 years the new sociology gave back a public face to sociology. This distinguishes it from the old sociology' that had not been 12. Sociology of Discourse DEFF Research Database (Denmark) Agustin, Oscar Garcia Sociology of Discourse takes the perspective that collective actors like social movements are capable of creating social change from below by creating new institutions through alternative discourses. Institutionalization becomes a process of moving away from existing institutions towards creating... 13. Medical sociology for whom? Science.gov (United States) Chaska, N L 1977-12-01 This article defines the role of a medical sociologist in a medical institution concerned with health care delivery. The role in applied research and teaching is also discussed. The distinction is made between sociology in medicine and sociology of medicine. Five broad areas of research included under the category of sociology of medicine are the consumer of health care; the social, cultural, and economic enviroments as they relate to health and illness; health and illness behavior; patient education; and the evaluation of services provided to the consumer. Research methodologies utilized by sociologists are briefly presented, and research issues of concern in the sociology of medicine are outlined. The knowledge and information provided by a medical sociologist are supplemental to the physician's practice and are expressed ultimately as a benefit for the patient. 14. Sociology of Drug Consumption OpenAIRE 2004-01-01 In this article which is a review of sociological ideas and studies of drug abusers in social situation, drug addiction steps (particularly alcohol, heroin and cocaine consumption) are revised and some explanations are made. Also, the role of some sociological ideas in drug addiction is considered in which Anomie Theory reads: "because of such duality, the individuals who are not satisfied with their role are in hurt." According to this theory, drug users choose seclusion and neglecting usual... 15. Regeneration through the ‘Pedagogy of Confrontation’: Exploring the Critical Spatial Practices of Social Movements in Inner City São Paulo as Avenues for Urban Renewal Directory of Open Access Journals (Sweden) Beatrice De Carli 2015-07-01 Full Text Available The city centre of São Paulo is increasingly a key site for local housing movements to challenge the rules and practices of spatial injustice in Brazil. In a context where housing for low-income groups is in short supply and, critically, continues to be characterized by highly skewed social and spatial distribution, occupied buildings have emerged as laboratories for the production of novel ways of inhabiting the city. This paper addresses on-going inner-city occupations as possible alternatives to the prevailing modes of conceiving and imagining urban renewal. As such, it outlines an approach to regeneration that engages processes of self-production and self-management as a means to achieve dignified homes and contest exclusionary urbanization. 16. Getting ready for reading: a follow-up study of inner city second language learners at the end of Key Stage 1. Science.gov (United States) Stuart, Morag 2004-03-01 A previous study (Stuart, 1999) showed that early phoneme awareness and phonics teaching improved reading and spelling ability in inner-city schoolchildren in Key Stage 1, most of whom were learning English as a second language. The present study, a follow-up of these children at the end of Key Stage 1, addresses four main questions: (1) Are these improvements maintained to the end of Key Stage 1? (2) Are different patterns of cognitive process evident in the word recognition skills of phonics trained versus untrained children? (3) Do the phonics trained children now also show a significant advantage in reading comprehension? (4) Are there differences in amount of reading, in self-concept as readers and in oral vocabulary development between phonics trained and untrained children? Relationships between reading and spelling ages and Key Stage 1 SATs levels are also explored. Data are reported from 101 seven-year-olds (85 of whom were second language learners) remaining from the original 112 children reported on previously. Children were tested on four standardized tests of reading, spelling and vocabulary, and on a further six experimental tests of phoneme segmentation, grapheme-phoneme correspondence knowledge, regular, exception and nonword reading, author recognition and reading self-concept. Lasting influences of early phoneme awareness and phonics teaching on phoneme awareness, grapheme-phoneme correspondence knowledge, word reading and spelling were found. Part of the previously untrained group had now received structured phonics teaching, and were therefore treated as a third (late trained) group. Early and late-trained groups showed similar levels of attainment and similar cognitive processing patterns, which were different from the untrained group. However, there were no influences of training on reading comprehension, self-concept or oral vocabulary. Early phoneme awareness and phonics training efficiently accelerates the word recognition and spelling 17. Small-scale variability of particulate matter and perception of air quality in an inner-city recreational area in Aachen, Germany Directory of Open Access Journals (Sweden) Bastian Paas 2016-06-01 Full Text Available Spatial micro-scale variability of particle mass concentrations is an important criterion for urban air quality assessment. In this study we present results from detailed spatio-temporal measurements in the urban roughness layer along with a survey to determine perceptions of citizens regarding air quality in an inner city park in Aachen, Germany. Particles were sampled with two different approaches in February, May, July and September 2014 using an optical particle counter at six fixed measurement locations, representing different degrees of outdoor particle exposure that can be experienced by a pedestrian walking in an intra-urban recreational area. A simulation of aerosol emissions induced by road traffic was conducted using the German reference dispersion model Austal2000. The mobile measurements revealed unexpected details in the distribution of urban particles with highest mean concentrations of PM(1;10$\\text{PM}_{(1;10}$inside the green area 100 m away from bus routes (arithmetic mean: 22.5 μg m−3 and 18.9 μg m−3; geometric mean: 9.3 μg m−3 and 6.5 μg m−3, whereas measurement sites in close proximity to traffic lines showed far lower mean values (arithmetic mean: 7.5 μg m−3 and 8.7 μg m−3; geometric mean: 5.8 μg m−3 and 6.5 μg m−3. Concerning simulation results, motor traffic is still proved to be an important aerosol source in the area, although the corresponding concentrations declined rapidly as the distances to the line sources increased. Further analysis leads to the assumption that particularly coarse particles were emitted through diffuse sources e.g. on the ability of surfaces to release particles by resuspension which were dominantly apparent in measured PM(1;10$\\text{PM}_{(1;10}$and PM(0.25;10$\\text{PM}_{(0.25;10}$data. The contribution of diffuse particle sources and urban background transport to local PM(0.25;10$\\text{PM}_{(0.25;10}\$ concentrations inside the
18. Towards a sociological analysis of London 2012
OpenAIRE
Silk, Michael L
2011-01-01
Within this article, I focus on a number of productive scholarly avenues to which sociological analysis of London 2012 might want to attend. Understanding major sporting events - and thus the Olympic Games - as inextricably entangled with the media-industrial complex, I suggest London 2012 as a commodity spectacle that will emphasize gleaming aesthetics, a (sporting) city and nation collapsed into (simple) tourist images, and the presentation of a particular expression of self within the logi...
19. Sociology of Hidden Curriculum
Directory of Open Access Journals (Sweden)
2017-06-01
Full Text Available This paper reviews the concept of hidden curriculum in the sociological theories and wants to explain sociological aspects of formation of hidden curriculum. The main question concentrates on the theoretical approaches in which hidden curriculum is explained sociologically.For this purpose it was applied qualitative research methodology. The relevant data include various sociological concepts and theories of hidden curriculum collected by the documentary method. The study showed a set of rules, procedures, relationships and social structure of education have decisive role in the formation of hidden curriculum. A hidden curriculum reinforces by existed inequalities among learners (based on their social classes or statues. There is, in fact, a balance between the learner's "knowledge receptions" with their "inequality proportion".The hidden curriculum studies from different major sociological theories such as Functionalism, Marxism and critical theory, Symbolic internationalism and Feminism. According to the functionalist perspective a hidden curriculum has a social function because it transmits social values. Marxists and critical thinkers correlate between hidden curriculum and the totality of social structure. They depicts that curriculum prepares learners for the exploitation in the work markets. Symbolic internationalism rejects absolute hegemony of hidden curriculum on education and looks to the socialization as a result of interaction between learner and instructor. Feminism theory also considers hidden curriculum as a vehicle which legitimates gender stereotypes.
20. Physical Education, Sociology, and Sociology of Sport: Points of Intersection.
Science.gov (United States)
Sage, George H.
1997-01-01
Examines the rise of sociology and physical education (PE), discussing linkages that initially existed and the separation that transpired between them. Also examines connections between social theory and PE before the sociology of sport was formally developed. Details the rise of sociology of sport, highlighting roles of physical educators. (SM)
1. Sport Sociology: Contemporary Themes.
Science.gov (United States)
Yiannakis, Andrew, Ed.; And Others
Intended for beginning and intermediate level students of sport and society, this anthology of 43 articles is organized into twelve, self-contained teaching units with unit introductions and study questions. Topics addressed include: (1) the sociological study of sport; (2) sport and American society; (3) the interdependence of sport, politics,…
2. Effect of Body Composition, Physical Activity, and Aerobic Fitness on the Physical Activity and Fitness Knowledge of At-Risk Inner-City Children
Science.gov (United States)
Brusseau, Timothy A.; Burns, Ryan D.; Hannon, James C.
2016-01-01
SHAPE America has highlighted the importance of developing physically literate children as part of quality physical education programming. Unfortunately, most children know little about physical activity and health-related fitness. The purpose of this study was to examine the physical activity and fitness content knowledge of at-risk inner-city…
3. Regional Sociological Research Experience
Directory of Open Access Journals (Sweden)
2015-11-01
Full Text Available The article presents the experience of the Institute of Socio-Economic Development of Territories of RAS in conducting sociological research on the territory of the Vologda Oblast and the Northwestern Federal District. It describes the historical aspects of formation of the system for public opinion monitoring and examines its theoretical and methodological foundations. The author of the article analyzes the structure of monitoring indicators and provides a brief interpretation of research findings that reflect social wellbeing and social perception trends. In addition, the paper analyzes people’s attitude toward the activities of federal and regional authorities, trends in social well-being, consumer sentiment and also the complex indicator – the index of public sentiment in the region – developed by ISEDT RAS researchers. The results of sociological studies carried out at ISEDT RAS correlate with the dynamics of the all-Russian public opinion polls conducted by the Institute of Sociology of the Russian Academy of Sciences, the Russian Public Opinion Research Center (VCIOM, Levada-Center, etc. They indicate that Russian society gradually adapts to new conditions of life after the collapse of the USSR. Besides, opinion polls show the most important features of the post-Soviet Russian history at its present stage; they are associated with the intensification of international political relations, the consequences of the “Crimean spring” and the new challenges Russia’s economy is facing now. The article concludes that as global community, of which Russian society is part, is evolving, sociological knowledge begins to play an increasingly important role in administration and national security; this is associated with the greater importance attached to intangible development factors. Therefore, a necessary prerequisite for administration effectiveness in all its stages is to implement the results of sociological research on social
4. Piketty's challenge for sociology.
Science.gov (United States)
Savage, Mike
2014-12-01
This paper argues that Piketty's book should not simply be seen as that of an economist, but that it contains significant resources for sociologists to draw upon. These are firstly, this approach to social science and his use of visualizations which chime closely with recent claims about the power of description. Secondly I consider his conceptualization of time and history - which in rebutting epochal arguments about the speed of contemporary change allows for a much better appreciation of the 'long durée'; and finally his conceptualization of social classes and privilege through his elaboration of a sociology of accumulation and inheritance. In all these ways, Piketty's work assists in developing an account of elites and wealth which should be highly productive for future sociology. © London School of Economics and Political Science 2014.
5. The idea of philosophical sociology.
Science.gov (United States)
Chernilo, Daniel
2014-06-01
This article introduces the idea of philosophical sociology as an enquiry into the relationships between implicit notions of human nature and explicit conceptualizations of social life within sociology. Philosophical sociology is also an invitation to reflect on the role of the normative in social life by looking at it sociologically and philosophically at the same: normative self-reflection is a fundamental aspect of sociology's scientific tasks because key sociological questions are, in the last instance, also philosophical ones. For the normative to emerge, we need to move away from the reductionism of hedonistic, essentialist or cynical conceptions of human nature and be able to grasp the conceptions of the good life, justice, democracy or freedom whose normative contents depend on more or less articulated conceptions of our shared humanity. The idea of philosophical sociology is then sustained on three main pillars and I use them to structure this article: (1) a revalorization of the relationships between sociology and philosophy; (2) a universalistic principle of humanity that works as a major regulative idea of sociological research, and; (3) an argument on the social (immanent) and pre-social (transcendental) sources of the normative in social life. As invitations to embrace posthuman cyborgs, non-human actants and material cultures proliferate, philosophical sociology offers the reminder that we still have to understand more fully who are the human beings that populate the social world. © London School of Economics and Political Science 2014.
6. Did Harriet Martineau's sociological methods influence Emile Durkheim's sociological methods?
OpenAIRE
Fritsch, Jon Eric
1995-01-01
Harriet Martineau (1802-1876) published How to Observe Morals and Manners in 1838. The book was perhaps the first sociological methodology text. Emile Durkheim (1855-1917) published The Rules of Sociological Method (1895) 57 years later. Durkheim's book has traditionally been labeled as the first sociological methodology text, while Martineau's book has been virtually forgotten by modern day sociologists. The author identifies significant similarities between the two tex...
7. 2004 American Sociological Association Presidential address: for public sociology*.
Science.gov (United States)
Burawoy, Michael
2005-06-01
Responding to the growing gap between the sociological ethos and the world we study, the challenge of public sociology is to engage multiple publics in multiple ways. These public sociologies should not be left out in the cold, but brought into the framework of our discipline. In this way we make public sociology a visible and legitimate enterprise, and, thereby, invigorate the discipline as a whole. Accordingly, if we map out the division of sociological labor, we discover antagonistic interdependence among four types of knowledge: professional, critical, policy, and public. In the best of all worlds the flourishing of each type of sociology is a condition for the flourishing of all, but they can just as easily assume pathological forms or become victims of exclusion and subordination. This field of power beckons us to explore the relations among the four types of sociology as they vary historically and nationally, and as they provide the template for divergent individual careers. Finally, comparing disciplines points to the umbilical chord that connects sociology to the world of publics, underlining sociology's particular investment in the defense of civil society, itself beleaguered by the encroachment of markets and states.
8. East Europe Report, Political, Sociological and Military Affairs
Science.gov (United States)
1984-09-28
sudden nervous disorder as an "attempted anamnesis ." Both grew up well cared for and normally in a suburban street of a GDR city. Yet Voellger does...This anamnesis of a genera- tion should be taken seriously, not only for literary reasons, but also in a sociological interest. 5885 CSO: 2300/638
9. Donald Pierson e a escola sociológica de Chicago no Brasil: os estudos urbanos na cidade de São Paulo (1935-1950 Donald Pierson and the Sociological School of Chicago in Brazil: urban studies in the city of São Paulo (1935-1950
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Edgar S.G. Mendoza
2005-12-01
influência da Escola de Chicago e sua repercussão no Brasil.This paper is an overview of the influence of Donald Pierson, formed in the Sociological School of Chicago, which had more repercussion on urban research in Brazil in the 1930s and 1950s, both within Sociology and Anthropology, in the city of São Paulo. Urban research in Brazil - both sociological and anthropological - had theoretical references that left their marks on the works of that time. According to my argument, regarding the scientific fields of anthropology and urban Sociology in Brazil, one of the theoretical trends in a certain historical and theoretical context was the Sociological School of Chicago. Revisiting pioneer urban studies in São Paulo could assert the influence of the School of Chicago. In spite of being isolated studies, they have strongly stressed properly urban issues. It would be risky to define them these days as Urban Sociology in its own right, in São Paulo. The reason for bringing them up is to demonstrate that they really represented antecedents to urban studies in Brazil between 1035-1950. Therefore, I can say that the sociology of the School of Chicago had its impact on three fields in Brazil: a racial relations (blacks, whites, and immigrants; b community studies (small rural towns; and c studies in the city (especially in São Paulo. Therefore, I think of the city of São Paulo as a scenario in general terms, as an agenda for institutional research in 1935-1950. Among the few and modest sociology studies having the city of São Paulo as their object, an ethnography of the city or urban ethnography was conducted that was different from classic studies on communities or small rural towns. Initially, we have eight works published mainly as journal articles, and their research object was some neighborhoods in São Paulo or other cities. The main feature of the article is the extensive bibliography found and presented at the end of the text, about the impact of the Scholl of
10. In Praise of Sociology.
Science.gov (United States)
Connell, Raewyn
2017-08-01
This reflection on the relevance of sociology starts with the different forms of social knowledge, and some autobiographical reflection on my engagement with the discipline. A research-based social science is made urgent by the prevalence of distortion and pseudoscience in the public realm. However, the research-based knowledge formation is embedded in a global economy of knowledge that centers on a privileged group of institutions and produces major imbalances on a world scale. Sociological data collection has important uses in policy and public discussion. But data need to be embedded in a larger project of understanding the world; this is what gives excitement to the work. Sociology has a potential future of marginality or triviality in the neoliberal economy and its university system. There are better trajectories into the future-but they have to be fought for. Cette réflexion sur l'utilité de la sociologie commence avec les différentes formes de savoir social, ainsi que quelques réflexions biographiques sur mon engagement avec la discipline. Le besoin d'une science sociale orientée vers la recherche est devenue nécessaire suite à la prédominance de la distorsion et de la pseudoscience dans la sphère publique. Par contre, ce savoir centré sur la recherche est lié à une économie globale de la connaissance qui est proche d'un groupe privilégié d'institutions et produit des déséquilibres majeurs au niveau mondial. La collecte de données sociologiques a une grande utilité en politique et dans les discussions publiques. Mais ces données doivent être liées à un projet plus large de compréhension du monde ; c'est ce qui rend ce travail excitant. La sociologie risque la marginalisation ou la trivialité dans une économie néo-libérale et son système universitaire. Il existe de meilleures trajectoires pour l'avenir - mais elles doivent être défendues. © 2017 Canadian Sociological Association/La Société canadienne de sociologie.
11. SD simulation study on degraded farmland policy on farming-pastoral area under the constrains of water resources-Taking Tongliao City of Inner Mongolia as example
Science.gov (United States)
Xu, D. P.; Zhao, B.; Li, T. S.; Zhu, J. W.; Yu, M. M.
2017-08-01
Water resources are the primary factor in restricting the sustainable development of farming-pastoral regions. To support the sustainable development of water resources, whether or not the land uses patterns of farming-pastoral areas is a reasonably important issue. This paper takes Tongliao city as example for the purpose of sustainably developing the farming-pastoral area in the north. Several scientific preductions and evaluations were conducted to study the farming-pastoral landuse pattern, which is the key problem that effects sustainable development of farming-pastoral areas. The paper then proposes that 1:7 landuse pattern is suitable for the sustainable development of farming-pastotal area. Based on the analysis of the research findings on sustainable development of farming-pastoral area, the paper established a suitability evaluation indicators system of degraded farmland policies in Tongliao city, and used an Analytical Hierarchy Process (AHP) method to determine the weight to run system dynamic (SD) model. The simulation results were then obtained on social economic ecological development in Tongliao city under different degraded farmland policies, and used the comprehensive evaluation model to optimize the results. It is concluded that stabilizing the policy of degraded farmland policy is the preferential policy in Tongliao, which provides useful theoretical research for the sustainable development of farming-pastoral area.
12. Toward Publicly Responsive Sociology Curricula: The Role of Introductory Sociology
Science.gov (United States)
Greenwood, Nancy A.
2013-01-01
Introductory sociology casts a wide net with regard to its audience and plays an important role in capturing the public eye as well as helping students to make more informed choices in their lives and communities. I ask six questions that help us as sociologists to think about how introductory sociology can better serve our discipline, our…
13. Sociology of Drug Consumption
Directory of Open Access Journals (Sweden)
2004-02-01
Full Text Available In this article which is a review of sociological ideas and studies of drug abusers in social situation, drug addiction steps (particularly alcohol, heroin and cocaine consumption are revised and some explanations are made. Also, the role of some sociological ideas in drug addiction is considered in which Anomie Theory reads: "because of such duality, the individuals who are not satisfied with their role are in hurt." According to this theory, drug users choose seclusion and neglecting usual social aims as well as competitive situations. Association of Differentiation Theory claims that drug use behavior is a learned behavior and the first learning occurs in a friendly small group (i.e. youngsters. Social Control theory believes that one can predict normal and abnormal behaviors through the rate of individuals' social commitments. Internal and external controls also determine commitment rate. Micro-cultural theory considers drug use as a compatibility with abnormal micro-culture rules. Symbolic Mutual Action Believes that the etiquettes which society attribute to individuals/behaviors determine their acquired social reactions rather than any inherited acquisition.
14. Teaching Sociology through Student Portfolios
Science.gov (United States)
Trepagnier, Barbara
2004-01-01
After several years of teaching Sociological Thought--an upper division course that focuses on classical, modern, and contemporary sociological theories--the author came across the idea of student portfolios. As a consequence, the course has undergone far-reaching changes. The content remains relatively intact; however, today the theory course…
15. Do Underachievers Need Sociology?
Directory of Open Access Journals (Sweden)
2009-12-01
Full Text Available This paper presents a promising model for using sociological learning to support the education of young people who are socially disadvantaged or display behavioral problems. A great many of these students are trapped in patterns of negative behavior. The goal of the model is to enable these young people to think explicitly about the role they are playing and to encourage them to strike out in a new direction. To this end, Erving Goffman’s sociological insights are used to stage a theatrical performance about school. This approach is informed by the microsociological tradition of proceeding from the concrete to the abstract in order to facilitate inductive learning and self-reflection. Goffman’s theory of social action provides the social-theoretical background for the theatrical action, while also serving as a medium of contrast for the analysis of the individual, interaction, and institution in subsequent reflections about school. In this way, sociological theory not only serves as a theoretical foundation for the lesson, but is also explicitly its subject.Der Aufsatz zeigt eine erfolgversprechende Möglichkeit auf, soziologisches Lernen als Beitrag zur Förderung sozial benachteiligter und verhaltensauffälliger Jugendlicher in der Schule zu implementieren. Die meisten dieser Schüler sind in ihren Handlungsmustern gefangen. Ziel ist es, diesen Jugendlichen die Möglichkeit zu eröffnen, bewusst über ihre Rolle nachzudenken und einen anderen Weg einzuschlagen. Hierfür werden Erkenntnisse aus Erving Goffman‘s Soziologie für ein schulisches Schauspiel genutzt, um ganz im Sinne der mikrosoziologischen Tradition vom Konkreten auf das Abstrakte zu schließen und damit induktives Lernen sowie Selbstreflexion zu ermöglichen. Goffman‘s Theorie sozialen Handelns bildet für das szenische Spiel zunächst das sozialtheoretische Hintergrundrauschen, um schließlich in der Reflexion der sozialen Situation in der Schule als Kontrastmittel f
16. Exploring access and attitudes to regular sexually transmitted infection screening: the views of young, multi-ethnic, inner-city, female students.
Science.gov (United States)
Normansell, Rebecca; Drennan, Vari M; Oakeshott, Pippa
2016-04-01
Low uptake of sexually transmitted infection (STI) testing by young people is a major public health problem worldwide. The aims of this qualitative, community-based study were to explore access and attitudes to STI screening in high risk, young, ethnically diverse female students. Qualitative semi-structured interviews were conducted at an inner-London further education college with 17 women aged 16-25 years. The women wanted convenient, regular STI testing and perceived this as responsible behaviour. However, they doubted the maturity of their peers who were unlikely to view themselves as candidates for testing, and feared the perceived stigma associated with testing. This was reflected in their preference for confidential testing. Despite attending their general practice for non-sexual health matters, most did not consider this option for STI testing. However, the long wait in specialist clinics was an important barrier. Many younger participants would not want postal STI sample kits sent to their homes. We found dissatisfaction with sexual health education. STI screening for underserved groups such as young sexually active ethnically diverse female college students needs to be confidential, convenient, easily accessed and offered in ways that allow them to consider themselves as candidates for such screening without fear of social stigma. Family doctors should be aware that young women often do not perceive primary care to be an option for accessing STI screening, and could consider ways of advertising these services. Policymakers and commissioners should be aware that clinic waiting times and lack of education remain barriers to testing. © 2015 John Wiley & Sons Ltd.
17. Sociological interpretation of social problems
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O. V. Katsora
2015-04-01
The article considers such sociological approaches to social problems as social pathology, social disorganization, functional and critical approaches, the approach of value conflict, constructionsite approach and the approach of «labelling». Each approach has its own peculiarities of consideration of social problems, that is related with the historical period in which it arose and settled down, and the views of members of a particular sociological approach to social problems. Also, the article discusses the main advantages and disadvantages of sociological approaches to dealing the social problems.
18. Measuring conflict management, emotional self-efficacy, and problem solving confidence in an evaluation of outdoor programs for inner-city youth in Baltimore, Maryland.
Science.gov (United States)
Caldas, Stephanie V; Broaddus, Elena T; Winch, Peter J
2016-08-01
Substantial evidence supports the value of outdoor education programs for promoting healthy adolescent development, yet measurement of program outcomes often lacks rigor. Accurately assessing the impacts of programs that seek to promote positive youth development is critical for determining whether youth are benefitting as intended, identifying best practices and areas for improvement, and informing decisions about which programs to invest in. We generated brief, customized instruments for measuring three outcomes among youth participants in Baltimore City Outward Bound programs: conflict management, emotional self-efficacy, and problem solving confidence. Measures were validated through exploratory and confirmatory factor analyses of pilot-testing data from two groups of program participants. We describe our process of identifying outcomes for measurement, developing and adapting measurement instruments, and validating these instruments. The finalized measures support evaluations of outdoor education programs serving urban adolescent youth. Such evaluations enhance accountability by determining if youth are benefiting from programs as intended, and strengthen the case for investment in programs with demonstrated success. Copyright © 2016 Elsevier Ltd. All rights reserved.
19. INNER TRACKER
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P. Sharp
The CMS Inner Tracking Detector continues to make good progress. The Objective for 2007 is to deliver to CMS a completed, installed, commissioned and calibrated Tracking System (Silicon Strip and Pixels) aligned to < 100µ in April 2008 ready for the first physics collisions at LHC. On 21 March 2007, the integration of the CMS Silicon Strip Tracker was completed with the successful integration of TEC- into the Tracker Support Tube (TST). Since then ~25% of the complete Tracker Systems has been commission at the TIF at both room temperature and operating temperature (-100 C), and the Tracker Community has gained very valuable experience in operating, calibrating and aligning the Tracker at the TIF before it is prepared for transportation to P5 in July 2007. The CMS Pixel System continues to make good progress. Module and Plaquette production is very well advanced. The first 25% of the Forward Pixel detector (Fpix) was delivered to CERN in April and the second 25% will shipped to CERN on 19 ...
20. INNER TRACKING
CERN Document Server
P. Sharp
The CMS Inner Tracking Detector continues to make good progress. The Objective for 2006 was to complete all of the CMS Tracker sub-detectors and to start the integration of the sub-detectors into the Tracker Support Tube (TST). The Objective for 2007 is to deliver to CMS a completed, installed, commissioned and calibrated Tracking System (Silicon Strip and Pixels) aligned to < 100µ in April 2008 ready for the first physics collisions at LHC. In November 2006 all of the sub-detectors had been delivered to the Tracker Integration facility (TIF) at CERN and the tests and QA procedures to be carried out on each sub-detector before integration had been established. In December 2006, TIB/TID+ was integrated into TOB+, TIB/TID- was being prepared for integration, and TEC+ was undergoing tests at the final tracker operating temperature (-100 C) in the Lyon cold room. In February 2007, TIB/TID- has been integrated into TOB-, and the installation of the pixel support tube and the services for TI...
1. INNER TRACKING
CERN Multimedia
P. Sharp
The CMS Inner Tracking Detector continues to make good progress. The successful commissioning of ~ 25% of the Silicon Strip Tracker was completed in the Tracker Integration Facility (TIF) at CERN in July 2007 and the Tracker has since been prepared for moving and installation into CMS at P5. The Tracker was ready to move on schedule in September 2007. The Installation of the Tracker cooling pipes and LV cables between Patch Panel 1 (PP1) on the inside the CMS magnet cryostat, and the cooling plants and power system racks on the balconies has been completed. The optical fibres from PP1 to the readout FEDs in the USC have been installed, together with the Tracker cable channels, in parallel with the installation of the EB/HB services. All of the Tracker Safety, Power, DCS and the VME Readout Systems have been installed at P5 and are being tested and commissioned with CMS. It is planned to install the Tracker into CMS before Christmas. The Tracker will then be connected to the pre-installed services on Y...
2. INNER TRACKING
CERN Multimedia
P. Sharp
The CMS Inner Tracking Detector continues to make good progress. The successful commissioning of ~ 25% of the Silicon Strip Tracker was completed in the Tracker Integration Facility (TIF) at CERN on 18 July 2007 and the Tracker has since been prepared for moving and installation into CMS at P5. The Tracker will be ready to move on schedule in September 2007. The Installation of the Tracker cooling pipes and LV cables between Patch Panel 1 (PP1) on the inside the CMS magnet cryostat, and the cooling plants and power system racks on the balconies has been completed. The optical fibres from PP1 to the readout FEDs in the USC will be installed in parallel with the installation of the EB/HB services, and will be completed in October. It is planned to install the Tracker into CMS at the end of October, after the completion of the installation of the EB/HB services. The Tracker will then be connected to the pre-installed services on YB0 and commissioned with CMS in December. The FPix and BPix continue to make ...
3. A sociological dilemma: Race, segregation and US sociology
Science.gov (United States)
2014-01-01
US sociology has been historically segregated in that, at least until the 1960s, there were two distinct institutionally organized traditions of sociological thought – one black and one white. For the most part, however, dominant historiographies have been silent on that segregation and, at best, reproduce it when addressing the US sociological tradition. This is evident in the rarity with which scholars such as WEB Du Bois, E Franklin Frazier, Oliver Cromwell Cox, or other ‘African American Pioneers of Sociology’, as Saint-Arnaud calls them, are presented as core sociological voices within histories of the discipline. This article addresses the absence of African American sociologists from the US sociological canon and, further, discusses the implications of this absence for our understanding of core sociological concepts. With regard to the latter, the article focuses in particular on the debates around equality and emancipation and discusses the ways in which our understanding of these concepts could be extended by taking into account the work of African American sociologists and their different interpretations of core themes. PMID:25418995
4. Methodological pluralism and structure of sociological theory
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N. L. Polyakova
2015-01-01
Full Text Available In the paper the historical-sociological analysis is used as a means to show the differences between theoretical and empirical sociology. There exist several, basic traditions in theoretical sociology. The investigation of their competing theoretical and methodological principles carried out in the paper; identify some fundamental features of sociological theory as a whole.
5. A Life with the Sociology of Education
Science.gov (United States)
Whitty, Geoff
2012-01-01
In this article, the author talks about a life with the sociology of education. He begins by describing the "old" and "new" sociologies of education. Then, he discusses the sociology of education policy and the relevance of Basil Bernstein, who remained the dominant presence within the sociology of education in the UK until his…
6. The Sociology of Zygmunt Bauman
DEFF Research Database (Denmark)
Jacobsen, Michael Hviid; Poder, Poul
significant as well as some of the lesser known and overlooked contributions of Zygmunt Bauman to contemporary sociology - ethics, freedom, utopia, genocide, metaphors, ambivalence, politics, strangers, globalization, power and consumerism. In separate chapters Bauman inspired scholars from the United Kingdom...
7. Følelser og sociologi
DEFF Research Database (Denmark)
Bo, Inger Glavind; Jacobsen, Michael Hviid
2017-01-01
En introduktion til bogen om følelsernes sociologi eller emotionssociologi - herunder om den ekspressive revolution og den affektive vending, om forskning i følelser og dens klassifikationer, tilgange, teorier og metoder....
8. Sport Sociology and the Discipline of Sociology: Present Status and Speculations about the Future.
Science.gov (United States)
Snyder, Eldon E.; Spreitzer, Elmer
The status of the sociology of sport within the discipline of sociology is explored. Review of the subfield since 1971 indicates an increase in the number of publications and communication relating to sport sociology topics. It is hypothesized, however, that sport sociology will not in the near future receive equal acceptance within sociology with…
9. Social History and Historical Sociology
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Wolfgang Knöbl
2018-01-01
Full Text Available This paper deals with exchanges and misunderstandings between the German school of social history (most prominently represented by scholars from the University of Bielefeld (such as Hans-Ulrich Wehler and Anglo-American trends in historical sociology (exemplified by the works of Barrington Moore, Theda Skocpol and Michael Mann. The social historians tended to dismiss historical sociology as too dependent on modernization theory, without taking into account the critique of that tradition by authors who brought processes of state formation and revolutionary change into the debate. On the other side, mainstream historical sociology worked with assumptions that limited its ability to change the terms and directions of sociological discourse, and to assimilate lessons from history. Among these inbuilt biases, organizational realism and materialism – particularly pronounced in the work of Michael Mann – stand out as particularly important. The paper closes with arguments in favour of bringing more history into historical sociology, with particular emphasis on three sets of problems. There is a need for more historical approaches to differentiation, less dependent on functionalist premises than the hitherto prevalent paradigm. A more explicit thematization of temporality in history and society would, among other things, help to clarify issues linked to the notion of path dependency. Finally, a reconsideration of the models and types of explanation in historical sociology would place more emphasis on their interpretive dimension.
10. Social History and Historical Sociology
Directory of Open Access Journals (Sweden)
Wolfgang Knöbl
2013-06-01
Full Text Available This paper deals with exchanges and misunderstandings between the German school of social history (most prominently represented by scholars from the University of Bielefeld (such as Hans-Ulrich Wehler and Anglo-American trends in historical sociology (exemplified by the works of Barrington Moore, Theda Skocpol and Michael Mann. The social historians tended to dismiss historical sociology as too dependent on modernization theory, without taking into account the critique of that tradition by authors who brought processes of state formation and revolutionary change into the debate. On the other side, mainstream historical sociology worked with assumptions that limited its ability to change the terms and directions of sociological discourse, and to assimilate lessons from history. Among these inbuilt biases, organizational realism and materialism - particularly pronounced in the work of Michael Mann - stand out as particularly important. The paper closes with arguments in favour of bringing more history into historical sociology, with particular emphasis on three sets of problems. There is a need for more historical approaches to differentiation, less dependent on functionalist premises than the hitherto prevalent paradigm. A more explicit thematization of temporality in history and society would, among other things, help to clarify issues linked to the notion of path dependency. Finally, a reconsideration of the models and types of explanation in historical sociology would place more emphasis on their interpretive dimension.
11. Regarding Bioethics: A Sociology of Morality.
Science.gov (United States)
De Vries, Raymond
2017-01-01
C. Wright Mills said that when done well, sociology illuminates the intersection of biography and history. This essay examines how the author's vocational choices and career path were shaped by historical circumstance, leading him to a degree in sociology and to participation in the odd and interesting interdiscipline of bioethics. Drawing on a distinction between sociology in bioethics and sociology of bioethics, the essay considers the value of sociology to the bioethical project.
12. Sociological concept of morale
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Marjanović Miloš
2012-01-01
Full Text Available The author first discusses the overall unity of the total normative regulation, from which it is separated in the late Roman empire the right, but only in the new century and the morale. There are analyzed the relationship between the moral and ethical reflection and Weber's distinction between pure ethics will (Gesinnungsethik and ethics of responsibility (Verantwortungsethik. The morale is determined by the good as the highest value, as a specific form of social norms but also as a kind of human behavior. These three definitions can be combined in an integrative approach. There are examined the dimensions of moral statements, subjective and objective side of morality, as well as the difference between morale and morality. A general notion of morale can not be defined in substantive but only in formal way . The formal definition is a constituent of general as well as of sociological concept of morale and it is related to morality as a social phenomenon. Its essence is to define the morale by specific norms, the characteristics of the internal and external mandatory (with the pricks of conscience as the most distinctive moral sanction and control exercised by the formal not institutionalized or diffuse society , and in consideration of morality as a social process (actions of people associated moral norms . The basic types of social moral process - being, education, functioning and changing of morale are described. There are briefly analyzed the influence of society to the morale and social function of morale, with special emphasis on the relationship between law and morale.
13. Sociological aspects of rhinoplasty.
Science.gov (United States)
Babuccu, Orhan; Latifoğlu, Osman; Atabay, Kenan; Oral, Nursen; Coşan, Behçet
2003-01-01
Although the psychological aspect of the rhinoplasty operation has been a subject of interest for a long time, with the exception of a few studies, sociological factors have been almost totally ignored. In this prospective study the personality characteristics and socioeconomic backgrounds of 216 rhinoplasty patients were evaluated. Between 1994 and 2000, a questionnaire and the Minnesota Multiphasic Personality Inventory (MMPI) were given preoperatively to 157 females and 59 males. The MMPI was also given to age-matched people as a control. Six months after surgery, patients were called on the telephone and asked to rate their satisfaction. According to questionnaire, a great majority of the rhinoplasty patients were young, unmarried women with high education levels. In the rhinoplasty group, one or more scales of the inventory were not in the normal ranges in 45% of the patients, whereas this proportion in the control group was 28% (p childish, highly active, impulsive, competitive, reactive, perfectionistic about themselves, talkative, and emotionally superficial. Male patients could be described as rigid, stubborn, over-sensitive, suspicious, perfectionistic, pessimistic, over-reactive, and having somatizations. Tension and anxiety with feelings of inferiority were found to be characteristics of the male patients. The satisfaction rate after six months was reported as 72%. There was no significant correlation between MMPI results and demographic variables, nor satisfaction rate. In conclusion, the rhinoplasty patients in our study are young people at the very beginning of their careers. It could be that their personalities and socioeconomic backgrounds combine to make aesthetic surgery rewarding enough, both socially and personally, to encourage them to follow through.
14. ‘Leaving no one behind’: reflections on the design of community-based HIV prevention for migrants in Johannesburg’s inner-city hostels and informal settlements
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Fiona Scorgie
2017-07-01
Full Text Available Abstract Background Unmanaged urban growth in southern and eastern Africa has led to a growth of informal housing in cities, which are home to poor, marginalised populations, and associated with the highest HIV prevalence in urban areas. This article describes and reflects on the authors’ experiences in designing and implementing an HIV intervention originally intended for migrant men living in single-sex hostels of inner-city Johannesburg. It shows how formative research findings were incorporated into project design, substantially shifting the scope of the original project. Methods Formative research activities were undertaken to better understand the demand- and supply-side barriers to delivering HIV prevention activities within this community. These included community mapping, a baseline survey (n = 1458 and client-simulation exercise in local public sector clinics. The intervention was designed and implemented in the study setting over a period of 18 months. Implementation was assessed by way of a process evaluation of selected project components. Results The project scope expanded to include women living in adjacent informal settlements. Concurrent sexual partnerships between these women and male hostel residents were common, and HIV prevalence was higher among women (56% than men (24%. Overwhelmingly, hostel residents were internal migrants from another province, and most felt ‘alienated’ from the rest of the city. While men prioritised the need for jobs, women were more concerned about water, sanitation, housing and poverty alleviation. Most women (70% regarded their community as unsafe (cf. 47% of men. In the final intervention, project objectives were modified and HIV prevention activities were embedded within a broader health and development focus. ‘Community health clubs’ were established to build residents’ capacity to promote health and longer term well-being, and to initiate and sustain change within their
15. [A sociological approach to the family].
Science.gov (United States)
Bruschini, C
1989-01-01
"This paper discusses the range and limits of some concepts of the family, related to theoretical perspectives and to possibilities of an empirical approach to this social group. It argues that in recent studies of the family one can find the symbolic outlook of anthropology on the one hand, which deepens the analysis of dynamics of family relationships, but is limited to strict segments of society. On the other hand, one can find demography and sociology surveys, capable of framing broad portraits which, although liable to generalization, are static and limited to family relations within the household. As an example of possible methodology, the paper describes the proceedings and results of [a study on] family structure and daily life in the city of Sao Paulo [Brazil], in which the author assembles some of the commented approaches, trying to overcome their limitations." (SUMMARY IN ENG) excerpt
16. What is analytical sociology? Towards sociology as 'normal science'
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Dekić Milovan
2013-01-01
Full Text Available In this paper I analyze the basics of analytical sociology, relatively new and in our scientific community little known intellectual movement. In the introductory part I try to identify the general causes of its occurrence. In the second part I provide its preliminary definition. In the third part I reconstruct its prehistory. In the fourth and main part I discuss the basis of its scientific program. In the final part I try to establish implications of the adoption of this program as a guide for the sociological enterprise in the future.
17. Medical sociology as a vocation.
Science.gov (United States)
Bosk, Charles L
2014-12-01
This article extends Weber's discussion of science as a vocation by applying it to medical sociology. Having used qualitative methods for nearly 40 years to interpret problems of meaning as they arise in the context of health care, I describe how ethnography, in particular, and qualitative inquiry, more generally, may be used as a tool for understanding fundamental questions close to the heart but far from the mind of medical sociology. Such questions overlap with major policy questions such as how do we achieve a higher standard for quality of care and assure the safety of patients. Using my own research, I show how this engagement takes the form of showing how simple narratives of policy change fail to address the complexities of the problems that they are designed to remedy. I also attempt to explain how I balance objectivity with a commitment to creating a more equitable framework for health care. © American Sociological Association 2014.
18. Latin american sociology's contribution to sociological imagination: analysis, criticism, and social commitment
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José Vicente Tavares-dos-Santos
2006-01-01
Full Text Available This paper tackles the role played by sociology in the analysis of the transformation processes in the Latin American societies, in following the construction process of both State and Nation, and in questioning the social issues in Latin America. Six periods of sociology in Latin America and in the Caribbean Islands are analyzed: (i sociology's intellectual inheritance; (ii the authoritative-teaching sociology; (iii the "scientific sociology" period and the configuration of the "critical sociology"; (iv the institutional crisis, consolidation of the "critical sociology", and the diversification of sociology; (v the sociology of authoritarianism, of democracy, and of exclusion; and (vi the institutional consolidation and the worldization of sociology in Latin America (from the year 2000 on. It can be said that the distinctive features of the sociological knowledge in the continent have been: internationalism, hybridism, critical approach to the processes and conflicts in the Latin American societies, and social commitment on the part of the sociologist.
Science.gov (United States)
Matthews, Ralph
2014-05-01
20. Non inner-city gentrification in Israel
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Amiram Gonen
2004-12-01
Full Text Available In the recent two decades, as result of growing preference among the Jewish middle class for detached residence, many suburbs and villages were subject to gentrification. Especially prone to gentrification, were housing estates built in the 1950s at low densities. It was, then, the increasing suburbanization middle-class households that brought about the gentrificati-on of these neighborhoods. A similar process took place in immigrant towns and villages on the periphery of metropolitan regions.
1. Resilience characteristics mitigate tendency for harmful alcohol and illicit drug use in adults with a history of childhood abuse: a cross-sectional study of 2024 inner-city men and women.
Science.gov (United States)
Wingo, Aliza P; Ressler, Kerry J; Bradley, Bekh
2014-04-01
2. Teaching Sociology and Womens’ Critical Thinking
OpenAIRE
2013-01-01
Introduction Sociology of Teaching sociology is seen as a fresh new place to explore the importance and role of critical thinking in the sociology of education has been one of the most important issues to consider.Principles of Sociology course ample opportunities for students to develop critical thinking skills and attitudes and serves as a missionary spirit, critical thinking has suggested an alternative,Areas has brought the development of critical thinking. Learn the basics of critical...
3. Can sociology help to improve nursing practice?
Science.gov (United States)
Matthews, David
The first in a five-part series on sociology offers an overview of the debate about the relationship between sociology and nursing. Although sociological education is currently limited within nurse education, there is a long-held argument for its relevance. With a growing emphasis on preventative and public healthcare, sociology may yet prove its usefulness. Subsequent articles cover four of the key social factors affecting health.
4. The Corpus Status of Literature in Teaching Sociology: Novels as "Sociological Reconstruction"
Science.gov (United States)
Carlin, Andrew P.
2010-01-01
Using fiction in teaching sociology involves what Harvey Sacks calls "sociological reconstruction". Numerous comments on teaching sociology provide advice and suggestions on the use of literature and "what counts" as "sociological" literature, including specific titles. This paper goes further: while the use of literature is a routine feature of…
5. Should We Talk about the Pain? Personalizing Sociology in the Medical Sociology Classroom
Science.gov (United States)
Nowakowski, Alexandra C. H.; Sumerau, J. E.
2015-01-01
This article discusses the potential of personalizing sociology curriculum, specifically in Medical Sociology courses, to increase student engagement and sociological awareness. Based on our experiences offering separate Medical Sociology courses at a large public research university and a small private teaching university, respectively, we…
6. [Psychological theory and implicit sociology.].
Science.gov (United States)
Sévigny, R
1983-01-01
This text is based on the hypothesis that every theory on the psychology of personality must inevitably, in one manner or another, have a sociological referent, that is to say, it must refer to a body of knowledge which deals with a diversity of social contexts and their relations to individuals. According to this working hypothesis, such a sociology is implicit. This text then discusses a group of theoretical approaches in an effort to verify this hypothesis. This approach allows the extrication of diverse forms or diverse expressions of this implicit sociology within this context several currents are rapidly explored : psychoanalysis, behaviorism, gestalt, classical theory of needs. The author also comments on the approach, inspired by oriental techniques or philosophies, which employs the notion of myth to deepen self awareness. Finally, from the same perspective, he comments at greater length on the work of Carl Rogers, highlighting the diverse form of implicit sociology. In addition to Carl Rogers, this text refers to Freud, Jung, Adler, Reich, Perls, Goodman, Skinner as well as to Ginette Paris and various analysts of Taoism. In conclusion, the author indicates the significance of his analysis from double viewpoint of psychological theory and practice.
7. Analytical Sociology: A Bungean Appreciation
Science.gov (United States)
Wan, Poe Yu-ze
2012-10-01
Analytical sociology, an intellectual project that has garnered considerable attention across a variety of disciplines in recent years, aims to explain complex social processes by dissecting them, accentuating their most important constituent parts, and constructing appropriate models to understand the emergence of what is observed. To achieve this goal, analytical sociologists demonstrate an unequivocal focus on the mechanism-based explanation grounded in action theory. In this article I attempt a critical appreciation of analytical sociology from the perspective of Mario Bunge's philosophical system, which I characterize as emergentist systemism. I submit that while the principles of analytical sociology and those of Bunge's approach share a lot in common, the latter brings to the fore the ontological status and explanatory importance of supra-individual actors (as concrete systems endowed with emergent causal powers) and macro-social mechanisms (as processes unfolding in and among social systems), and therefore it does not stipulate that every causal explanation of social facts has to include explicit references to individual-level actors and mechanisms. In this sense, Bunge's approach provides a reasonable middle course between the Scylla of sociological reification and the Charybdis of ontological individualism, and thus serves as an antidote to the untenable "strong program of microfoundations" to which some analytical sociologists are committed.
8. Sociological analysis and comparative education
Science.gov (United States)
Woock, Roger R.
1981-12-01
It is argued that comparative education is essentially a derivative field of study, in that it borrows theories and methods from academic disciplines. After a brief humanistic phase, in which history and philosophy were central for comparative education, sociology became an important source. In the mid-50's and 60's, sociology in the United States was characterised by Structural Functionalism as a theory, and Social Survey as a dominant methodology. Both were incorporated into the development of comparative education. Increasingly in the 70's, and certainly today, the new developments in sociology are characterised by an attack on Positivism, which is seen as the philosophical position underlying both functionalism and survey methods. New or re-discovered theories with their attendant methodologies included Marxism, Phenomenological Sociology, Critical Theory, and Historical Social Science. The current relationship between comparative education and social science is one of uncertainty, but since social science is seen to be returning to its European roots, the hope is held out for the development of an integrated social theory and method which will provide a much stronger basis for developments in comparative education.
9. Sociological theories of subjective well-being
NARCIS (Netherlands)
R. Veenhoven (Ruut)
2009-01-01
textabstractSubjective well-being is no great issue in sociology; the subject is not mentioned in sociological textbooks (a notable exception is Nolan & Lenski, 2004) and is rarely discussed in sociological journals. This absence has many reasons: pragmatic, ideological, and theoretical. To begin
10. City 2020+
Science.gov (United States)
Schneider, C.; Buttstädt, M.; Merbitz, H.; Sachsen, T.; Ketzler, G.; Michael, S.; Klemme, M.; Dott, W.; Selle, K.; Hofmeister, H.
2010-09-01
This research initiative CITY 2020+ assesses the risks and opportunities for residents in urban built environments under projected demographic and climate change for the year 2020 and beyond, using the City of Aachen as a case study. CITY 2020+ develops scenarios, options and tools for planning and developing sustainable future city structures. We investigate how urban environment, political structure and residential behavior can best be adapted, with attention to the interactions among structural, political, and sociological configurations and with their consequences on human health. Demographers project that in the EU-25-States by 2050, approximately 30% of the population will be over age 65. Also by 2050, average tem¬peratures are projected to rise by 1 to 2 K. Combined, Europe can expect enhanced thermal stress and higher levels of particulate matter. CITY 2020+ amongst other sub-projects includes research project dealing with (1) a micro-scale assessment of blockages to low-level cold-air drainage flow into the city centre by vegetation and building structures, (2) a detailed analysis of the change of probability density functions related to the occurrence of heat waves during summer and the spatial and temporal structure of the urban heat island (UHI) (3) a meso-scale analysis of particulate matter (PM) concentrations depending on topography, local meteorological conditions and synoptic-scale weather patterns. First results will be presented specifically from sub-projects related to vegetation barriers within cold air drainage, the assessment of the UHI and the temporal and spatial pattern of PM loadings in the city centre. The analysis of the cold air drainage flow is investigated in two consecutive years with a clearing of vegetation stands in the beginning of the second year early in 2010. The spatial pattern of the UHI and its possible enhancement by climate change is addressed employing a unique setup using GPS devices and temperature probes fixed to
11. Toward a Sociology of Oceans.
Science.gov (United States)
Hannigan, John
2017-02-01
Despite covering around 70 percent of the earth's surface, the ocean has long been ignored by sociology or treated as merely an extension of land-based systems. Increasingly, however, oceans are assuming a higher profile, emerging both as a new resource frontier, a medium for geopolitical rivalry and conflict, and a unique and threatened ecological hot spot. In this article, I propose a new sociological specialty area, the "sociology of oceans" to be situated at the interface between environmental sociology and traditional maritime studies. After reviewing existing sociological research on maritime topics and the consideration of (or lack of consideration) the sea by classic sociological theorists, I briefly discuss several contemporary sociological approaches to the ocean that have attracted some notice. In the final section of the paper, I make the case for a distinct sociology of oceans and briefly sketch what this might look like. One possible trajectory for creating a shared vision or common paradigm, I argue, is to draw on Deleuze and Guattari's dialectical theory of the smooth and the striated. Même s'il couvre 70% de la surface de la Terre, l'océan a été longtemps ignoré en sociologie ou traité comme une extension des systèmes terrestres. De plus en plus, toutefois, l'océan retient l'attention, en étant vu comme une nouvelle frontière en termes de ressources, un médium pour les rivalités et les conflits géopolitiques, et un lieu écologique névralgique et unique. Dans cet article, je propose une nouvelle spécialisation sociologique, la 'sociologie des océans', se situant dans l'interface entre la sociologie environnementale et les études maritimes traditionnelles. Après une recension de la recherche sociologique existante sur les sujets maritimes et la prise en compte (ou l'absence de prise en compte) de l'océan par les théoriciens de la sociologie classique, je discute brièvement quelques approches sociologiques contemporaines de l
12. Sociology, medicine and the construction of health-related sociology.
Science.gov (United States)
Barros, Nelson Filice de; Nunes, Everardo Duarte
2009-02-01
Starting from a paper about closing the gap between sociology and medicine in Brazil and the United Kingdom that was published in 1971, a historical update was made with the aim of reflecting on the new shapes of health-related teaching and research within the social and human sciences, in these two countries. The methodology was qualitative and the study was developed using secondary data. The reflections were developed through the authors' immersion in Brazilian and British realities. It was concluded that the interface between sociology and health has expanded, although persistent old difficulties exist in relation to the structure and focus of the healthcare system, medical school power and medical student culture.
13. John Foran’s sociology of revolution: From historical sociology to the sociological imagination
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D Yu Karasyev
2014-12-01
Full Text Available The article considers J. Foran’s sociology of revolution through the stages of evolution of his theoretical and methodological views and the works representing them. The trajectory of Foran’s sociology of revolution reflects in many respects the development of the contemporary comparative and historical sociology of revolution: from the fundamental historical research of a few classical cases to the quantitative study of an extremely wide range of examples and after that to the prediction of the ‘revolution-like’ events’ in future. According to Foran, there are three ways to consider the future of revolutions: 1 the analysis of the revolutions of the past, 2 the look into the future in terms of the existing theories, 3 the sources of sociological imagination. These three methods correspond to three stages in Foran’s sociology of revolution: after conducting the historical study of the situation and revolutions in Iran, the comparative analysis of 39 revolution events in the Third World countries and then an attempt to imagine patterns of future revolutions on the example of Zapatistas’ revolution in Mexico in 1994 and the struggle for global justice at the beginning of the XXI century. Despite the evolution of the subject and methodology of the theory, the concept ‘political culture of opposition’ remained the central category of Foran’s model. This complex notion describes such social process when under the influence of material and discursive elements the revolutionaries found out some common discourse that prescribed them to participate in collective actions to change their societies. Thus, Foran states that revolutions are the product of both structural conditions and human agency and the latter is due to both political-economic and cultural reasons. The cultural-structural character of Foran’s approach makes it relevant for the study of contemporary revolutionary events.
14. Sociology: a view from the diaspora.
Science.gov (United States)
Rosenfeld, Richard
2010-12-01
From the vantage point of criminology, one of sociology's main export subject areas, the present and future of sociology appear a good deal more promising than John Holmwood's essay on the discipline's misfortune would suggest. Sociology remains in high demand by students and faculty hiring remains strong, even in its more critical sub-fields, such as race and ethnicity, sex and gender, and social inequality. Holmwood is correct that sociology is vulnerable to external pressures to demonstrate its relevance to social practice, but those pressures come from left-wing social movements as well as from centres of power. He is also correct that external pressures contribute to internal disagreement, but sociology has been at war with itself since the 1960s, with little evident decline in its academic standing or intellectual vitality. Those of us on the discipline's diaspora, who depend on sociology for both support and light, must remain hopeful about sociology's continued good fortune.
15. Reflexive criteria of sociological research
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R T Ubaydullaeva
2014-12-01
Full Text Available The article is devoted to the sociological criteria of explaining the way of thinking and actions of subjects, their spiritual and moral positions and intellectual forces that form the laws of social life. The author seeks to adapt such categories as ‘meaning of life’, ‘human dignity’, ‘rationality’ etc. for the purposes of sociological analysis by methodological construction of some real life dichotomies such as ‘subjective meaning and social function’, ‘the real and the ideal’, ‘the demanded and the excluded’. Thus, the author studies economic, political and technical processes in terms of both positivity and negativity of social interaction and states that given the increasing differentiation of the society and the contradictory trends of social development the reflexive criteria that take into account the socio-cultural nature of the man help to find one’s own model of development.
16. The Sociology of Zygmunt Bauman
DEFF Research Database (Denmark)
Jacobsen, Michael Hviid; Poder, Poul
Zygmunt Bauman is one of the most inspirational and controversial thinkers on the scene of contemporary sociology. For several decades he has provided compelling analyses and diagnoses of a vast variety of aspects of modern and liquid modern living. His work is increasingly popularized, appraised...... life and intellectual trajectory published here for the first time in English. In this postscript aptly entitled "Pro Domo Sua" ("About Myself"), he describes the pushes and pulls that throughout the years have shaped his thinking....
17. [A sociological approach to vulnerability].
Science.gov (United States)
Pelège, Patrick
2012-01-01
The term precarity covers many realities. It has become one of those "portmanteau words" which, as a resuIt of being constantly reassessed, is losing its meaning. In order to avoid an overly sectional approach to the mechanisms of social precarity, or exclusion, it is necessary to understand in more general terms the sociological processes around the concept of the social tie and its effects of rupture.
18. Dementia: sociological and philosophical constructions.
Science.gov (United States)
Davis, Daniel H J
2004-01-01
This analysis presents a challenge to the biomedical view of dementia as a disease. This view is critiqued from two perspectives: those of sociology and philosophy. Because these domains inform the creation of the medical discourse, their analysis provides an important refinement to the apprehension of the phenomenon of dementia. From the work of Foucault, and in particular his analysis of the historical origins of modern medicine, the sociological construction of dementia is considered. Following this, the philosophical question of Being is discussed, considering particularly the positions of Heidegger and Merleau-Ponty. Lastly aspects of dementia nursing that are damaging to those relatives forced to take on the role of primary carer are isolated, in the context of Kitwood's view that it is possible to maintain personhood at the extremes of this condition. It is suggested that this critique of sociological and philosophical foundations of dementia might offer a way of approaching the dismantling of the self and revise current conceptions of dementia care for the better.
19. Sociological theory and Jungian psychology.
Science.gov (United States)
Walker, Gavin
2012-01-01
[[disenchantmentCarl JungpsychoanalysissociologyMax Weber ] In this article I seek to relate the psychology of Carl Jung to sociological theory, specifically Weber. I first present an outline of Jungian psychology. I then seek to relate this as psychology to Weber’s interpretivism. I point to basic methodological compatibilities within a Kantian frame, from which emerge central concerns with the factors limiting rationality. These generate the conceptual frameworks for parallel enquiries into the development and fate of rationality in cultural history. Religion is a major theme here: contrasts of eastern and western religion; the rise of prophetic religion and the disenchantment of modernity. Weber’s categories ‘ascetic’ and ‘mystic’ seem applicable to his own and Jung’s approaches and indeed temperaments, while a shared ironic view of rationality leads to similar visions of the disenchanted modern world. I conclude that Jung is sociologically coherent, but in an entirely different sense from Freud: rather than a constellation of family, socialization, ideology, social continuity, there is an analysis of cultural history against a background of adult normal psychology. I conclude that sociology should acknowledge Jung, but not in terms of over-arching theory. Rather Jungian insights might be used to orient new enquiries, and for reflexive analysis of sociology’s methodological debates.
20. Sociology of bodies/emotions
Directory of Open Access Journals (Sweden)
2012-12-01
Full Text Available This paper aims at pointing out that the division between a sociology of the bodies and the emotions is, to say the least, unnecessary. The basic idea that runs through this argument is very simple but needs to be justified: it is not possible to search and reflect on bodies/emotions separately, as if it were any chance of one not referring to the other and viceversa. The strategy of the exposition we have selected is as follows: 1 we outline in an introductory manner the existing approaches in the social studies on bodies and emotions, 2 we point out three kinds of reasons/motives to argue the inadequacy of the categorical/aporetic division of a sociology of the bodies and one of the emotions, 3 we put forward our perspective regarding a sociology of bodies/emotions, and 4 we analize the problem of hunger as an example of our viewpoint. Finally, we invite to reflect on the exposed as a means to open a possible discussion in methodological, theoretical, epistemological and political terms.
1. Modern Kültürde Kentten Kaçmanın ve Uzaklara Gitmenin Sosyolojisi / The Sociology of Escaping from the City and Going far away in the Modern Culture
Directory of Open Access Journals (Sweden)
Sertaç Timur DEMİR
2017-08-01
Full Text Available Bu makale bir tür kurtuluş reçetesine dönen doğaya bedensel, zamansal ve mekânsal deneyimler üzerinden odaklanmaktadır. Önceleri kent tarzı yaşamı arzulayan modern birey artık kentten sıkılmış ve yeni arayışlar içine girmiştir. Bugün bu yönelimin merkezi doğadır. Bu açıdan uzak coğrafyalar üzerinde cereyan eden geri dönüş hikâyesini tartışmanın tam vaktidir. Çünkü büyük kentlere büyük hayallerle göç edenlerin beklentileri imtihan edilmiş, düş kırıklıkları yaşanmış ve yıllar sonra terkedilen eski köyler yeniden özlenmeye başlanmıştır. Bu bağlamda mazi ve hatıra mekânı olarak doğa ve taşra el değmemiş ve bozulmamış olarak tasavvur edilmiş ve kentin mutlak bir antitezi olarak benimsenmiştir. Burada beliren ana soru bakir ve arınmış doğanın kentleşmeyi merkezileştiren modern toplum figürasyonu tarafından kapsam dışı tutulup tutulmadığıdır. Başka bir deyişle, kentte bunalan modern birey için doğaya kaçış ya da taşraya dönüş kalıcı bir çözüm mü yoksa geçici bir avuntu mudur? Tüm bu ikircikli sorunsallar bu çalışmanın çerçevesini oluşturmaktadır. / This article focuses on the nature that has turned into a kind of salvation recipe in recent years through bodily, temporal and spatial experiences. The modern individual who once desired urban-style life now gets bored of it and embarks on new quests. Today the centre of the orientation is nature. In this sense, it is high time to debate the story of returning that take places on distant geographies because the expectations of those who migrated to big cities with dreams have been tested, then they had disappointments and once left villages started to be missed again after years. In this context, the nature and province as the place of past and memory are conceived as untouched and intact and as an absolute antithesis of the city. The main question that rises here is whether or not the virgin
2. Pure sociology and social geometry as an example of formal sociological theory
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Škorić Marko
2012-01-01
Full Text Available This paper analyzes pure sociology and social geometry of Donald Black as an example of formal sociological theory. Starting with the importance of formal and analytical theory in sociology, we present the bold theoretical strategy and/or the paradigm of the sociology of behavior of social life. The examples of pure sociology and social geometry concerning law, violence and homosexuality are presented as well. A review and critique of pure sociology as a scientific formal theory is offered in the end.
3. Superlinear scaling for innovation in cities.
Science.gov (United States)
Arbesman, Samuel; Kleinberg, Jon M; Strogatz, Steven H
2009-01-01
Superlinear scaling in cities, which appears in sociological quantities such as economic productivity and creative output relative to urban population size, has been observed, but not been given a satisfactory theoretical explanation. Here we provide a network model for the superlinear relationship between population size and innovation found in cities, with a reasonable range for the exponent.
4. Love, from a sociological point of view
Directory of Open Access Journals (Sweden)
Chiara Piazzesi
2015-08-01
Full Text Available What does it mean to examine erotic love and intimacy from a sociological point of view? Does this endeavour entail a definition of love, and, if so, is such a definition possible from a sociological perspective? This paper discusses the epistemological challenges implied by the task of constructing love as the object of sociological inquiry. We will start by giving a definition of the task itself and by detailing the peculiarities of a sociological inquiry on love. We will point out why it is imperative for such an inquiry to remain open to the historicity of love as an emotion and as a form of interaction. Finally we will explore love as the object of a sociological investigation in order to spell out what becomes visible to the sociological eye once the correct epistemological precautions are taken.
5. Comparative education and the ?new? sociologies
Science.gov (United States)
Trusz, Andrew R.; Parks-Trusz, Sandra L.
1981-12-01
The authors examine the impact of the new' sociologies on comparative education by reviewing five comparative readers published during the past twenty years. While the new' sociologies have had considerable impact within sociology and the sociology of education, minimal impact is found within comparative education. The authors further show that while critical new sociologies such as Marxism, neo-Marxism, and Critical theory have had some penetration into comparative education, use of the interpretative sociologies such as symbolic interactionism, ethnomethodology, and semiotics has generally been absent. The authors conclude by suggesting that a synthesis of the critical and interpretative modes would prove fruitful for further work in comparative education. The five texts are: Halsey, Floud and Anderson (eds.), Education, Economy and Society (1961); Eckstein and Noah (eds.), Scientific Investigations in Comparative Education (1969); Beck, Perspectives on World Education (1970); Karabel and Halsey (eds.), Power and Ideology in Education (1977); and Altbach and Kelly (eds.), Education and Colonialism (1978).
6. In search of the kingdom: the social gospel, settlement sociology, and the science of reform in America's progressive era.
Science.gov (United States)
Williams, Joyce E; Maclean, Vicky M
2012-01-01
This critical narrative history examines the development of sociology in the United States during what has come to be labeled as the Progressive Era, roughly the years from the 1890s to World War I. Despite the label, this era was defined as much by social problems associated with industrialization, urbanization, and immigration as by the growth of its cities and the wealth of its capitalists. We explore the roots of American sociology in the transition of protestant theology from Calvinism to its reformation in the social gospel, the simultaneous development of settlement houses, and the "creation" of sociology as the science of reform. © 2012 Wiley Periodicals, Inc.
7. Audiological rehabilitation in sociological perspectives
DEFF Research Database (Denmark)
Hindhede, Anette Lykke
, or they can relate to particular situations. On entering the hearing clinic for the first time, many patients express discomfort when confronted with becoming partners in decision-making concerning the choice of hearing aid type. In the fitting room, the audiologist operates within a dominant medical...... as the 'truth'. By building on a sociological approach to hearing impairment that reaches beyond the medical definition, we see another picture emerging. Some patients embark on the process of getting a hearing aid and come to the hearing aid fitting as a response to social pressure from relatives or colleagues...
8. Sociologi
DEFF Research Database (Denmark)
Sandholm, Niels
2016-01-01
I kapitlet diskuteres ud fra et sociologisk perspektiv brug af et screeningsinstrumentet til opsporing af depression efter indlæggelse for hjertesygdom. HADS – Hospital Anxiety and Depression Scale Det er en udbredt praksis at screene udskrevne hjertepatienter for depression. Som screeningsinstru...
9. Toward a Sociology of Environmental Flows: A New Agenda for Twenty-First-Century Environmental Sociology
NARCIS (Netherlands)
Mol, A.P.J.; Spaargaren, G.
2006-01-01
The emerging sociology of networks and flows, as it can be found in the works of Castells and Urry among others, offers promising perspectives for environmental sociology in rethinking its principle object of study: nature and environment. The sociology of flow perspective takes us beyond the
10. The Fourth Sociology and Music Education: Towards a Sociology of Integration
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Wright, Ruth
2014-01-01
By identifying three main sociologies that characterise broad movements in the field since its inception, this paper provides a background to considerations of music education from the perspective of sociology. A fourth sociology is then proposed that may be useful to interrogate the complexities of the field of 21st century music education. This…
11. A Sociology "of" or a Sociology "for" Education? The New Zealand Experience of the Dilemma
Science.gov (United States)
Rata, Elizabeth
2010-01-01
The sociology of education in New Zealand, as in other countries, is affected by the dilemma inherent to the discipline, namely: is it a sociology "of" education or a sociology "for" education? In this article I analyse three factors in which the dilemma is played out: "cultural oppositionism" in the indigenous…
12. The sociological subject through the streets of Brasília
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Roberta Tiburri
2013-12-01
Full Text Available This article discusses the sociological subject, as conceptualized by Stuart Hall (2006, in the modernist architecture and urbanism, using the city of Brasilia as an icon. The sociological subject is the result of modernity in transformation, with its characteristics of isolation and individualism, together with a process of decentralization and fragmentation of identities. This idea will be led through the streets of the city-symbol of our modernism, largely designed from the principles of the Athens Charter, which aimed to solve the problems caused by rapid growth of cities. We try to understand how the modernist principles of the Athens Charter, who are considered to be the most significant manifest of the International Congress of Modern Architecture (CIAM, are present in Brasilia and how both the collective and the individual interact as well as how the sociological subject can move about those spaces. To do so, we analyze the principles of the Athens Charter, applied to Brasilia’s urban design, and determine how our sociological subject in practice interacts with this “ideal city” by observing the interactions between the collective, the individual, the public and private, the center, and the periphery. We also consider the political and economic conditions in Brasilia during the 1950s and early 1960s, under the developmental policy of President Kubitschek, combined with the precepts of the ideal modern city. Thus, our analysis focuses on the sociological subject, who is individualistic and changes modern society, interacting with the structures of the nation-state, industrialization, democracy, and modern capitalism, and is part of a modernist city, with aspirations of community and social and spatial order in a country facing the future, progress, and development.
13. Inner Magnetospheric Physics
Science.gov (United States)
Gallagher, Dennis
2018-01-01
Outline - Inner Magnetosphere Effects: Historical Background; Main regions and transport processes: Ionosphere, Plasmasphere, Plasma sheet, Ring current, Radiation belt; Geomagnetic Activity: Storms, Substorm; Models.
14. Sociological theory and social reality
Directory of Open Access Journals (Sweden)
J Díez Nicolás
2014-12-01
Full Text Available This paper pretends to demonstrate the complementary relations between three relatively recent sociological theories, each one of which explains a different aspect of the same social object: the origin, diffusion and change of social and cultural values, aiming at demonstrating that there is not such a thing as a sociological theory that explains all, but rather diverse theories that offer partial explanations of social reality. To that effect, and on the basis of the necessary relationship between theory and research, three different theories are evaluated separately: Hawley’s and Duncan’s theory of the social ecosystem, Galtung’s centre-periphery theory, and Inglehart’s theory of values’ change in modern-industrial societies, offering theoretical and empirical evidence of their complementary relations, based on Spanish and international data. Social ecosystem and centre-periphery theories show a high level of generalization (through space and time and a high level of abstraction, though both can easily operationalize their main concepts through valid and reliable indicators. The theory of values’ change, however, though showing a high level of generalization, is limited in time to the historical period after World War II, and also shows a high level of abstraction. Centre-periphery theory and values’ change theory use individual and collective units of analysis, but social ecosystem theory only uses collective units, by definition. The three theories lead to the conclusion that ‘security’ values will gain a growing importance in present societies.
15. Toward a Global Sociology of Religion
Science.gov (United States)
Parvez, Z. Fareen
2017-01-01
This article offers an example of a global approach to teaching the sociology of religion, a course that typically focuses on American religious phenomena. It builds on three interventions in the movement for a global sociology: connecting the local and global, moving beyond methodological nationalism, and developing an ethical orientation toward…
16. Psychological and Sociological Determinants of Academic ...
African Journals Online (AJOL)
This study investigated the psychological and sociological determinants of academic achievement of school-going adolescents. Six self-report measures were administered randomly to 280 senior secondary III students in Ibadan. Results showed that the six psychological and sociological factors (motivation, anxiety, and ...
17. One Hundred Years of Sociological Solitude?
Science.gov (United States)
Rumbaut, Ruben G.
2005-01-01
This Cuban-born author presents a narrative on the social events in the United States that marked his life as he embarked on a career in the field of sociology in the 1960s and 70s. He advocates for sociologists' awareness of social realities and the evolution of sociological studies from a socially-conscious perspective.
18. [Where are we in general sociology ?].
Science.gov (United States)
Brian, Eric
2012-01-01
Over the last two decades, history and social sciences have experienced a kind of merging, and a vast number of specialized domains have emerged. Yet the durkheim - ian register of "general sociology" seems somehow neglected. Firstly, this article analyzes the reasons for this neglect, and secondly, it indicates how, through a long-term reflexivity, one can formulate a new agenda for general sociology.
19. Sociology and Social Work in Nigeria: Characteristics ...
African Journals Online (AJOL)
This paper presents the evolution of sociology and social work in Nigeria and examines the current characteristics and areas of convergences and divergences in both fields. It was only in the 1960s that universities in Nigeria began to offer degree programmes in sociology with the. first sub-department and full department ...
20. Sociology of education, comparative education and social problems: A Polish comment
Science.gov (United States)
Zelazkiewicz, Marek
1981-12-01
The interaction and co-operation between the sociology of education and comparative education may lead to the realisation of the three basic functions of science: descriptive, explanatory and operative. A presentation of these issues is difficult because of the blurring of lines of division between related scientific disciplines. In the past two decades, Polish sociology has developed without experiencing any serious inner conflicts. Two basic orientations — empirical and humanistic — have co-existed, and the Marxist approach has gradually become more firmly established. The sociological approach applied to the sciences can be viewed as first, the adoption of sociological concepts and theories; and secondly, the application of the methods and techniques used in sociological research. The history of the relationship between the sociology of education and comparative education goes back to the works of J. Chałasiński in the 'thirties: he approached the school as a social institution functioning in a system of social relations and social groups, such as classes, vocational groups, nations and states. The application and impact of the sociological approach is evident in the methodological foundations of pedagogy — as e.g., in the work of Muszyński in 1975 — and also in many specific fields of comparative education. The so-called humanistic orientation and the descriptive function have predominated over empirical studies and the explanatory function in these areas. The 1973 Report of the Committee of Experts, on the state of education in Poland, was the result of co-operation between sociologists end educationists. This enterprise brought about the actualisation of the operative function of both scientific disciplines. However, the situation in Poland today raises new questions needing to be answered.
1. The high-rise building. A review of sociological approaches for study
Directory of Open Access Journals (Sweden)
Jorge Vergara Vidal
2017-12-01
Full Text Available The verticalization of Chilean cities is a phenomenon that attracts the public interest and requires an understanding that exceeds the economic reasons and technical possibilities that lead to the proliferation of high buildings within them. This paper reviews in the sociological literature the treatment given to high-rise buildings with the aim of providing clues that collaborate with the social study of these architectural forms. The conclusions identify an epistemological turn that has allowed tools to link the architectural, material and technical aspects involved in high-rise buildings with the sociological analysis of these.
2. French Economics of Convention and Economic Sociology
DEFF Research Database (Denmark)
Jagd, Søren
foundation of markets and of money may be an occasion for economic sociology to focus even more on elaborating on the institutional void created by traditional economic theory. A second point is that economic sociology could benefit from the perspective of a plurality of forms of coordination involved......The French Economics of convention tradition has developed to be an influential research tradition situated in the area between economics and sociology. The aim of the paper is to explore some of the themes that may be common to economics of conventions and economic sociology by looking more...... closely into three recent texts from the economics of convention tradition discussing, in slightly different ways, differences and similarities between economics of convention and economic sociology. It is argued that André Orléan’s point that a common aim could be to ‘denaturalise’ the institutional...
3. Economics of Convention and New Economic Sociology
DEFF Research Database (Denmark)
Jagd, Søren
2007-01-01
The aim of the article is to explore potential common themes in economic sociology and economics of conventions. The article explores two issues raised by economics of conventions that may be of particular importance to economic sociology. First, the explicit exploration of the consequences...... of a plurality of forms of justification, as elaborated in économie de la grandeur. This perspective was recently taken up in economic sociology by David Stark's introduction of the notion ‘sociology of worth'. The second issue, recently suggested by André Orléan, is the need to denaturalize economic theory...... and economic action to demonstrate the social constructed nature of economic action. It is argued that these two issues demonstrate that a fruitful dialogue is indeed possible between economic sociology and economics of convention and should be encouraged....
4. Sociology as Moral Philosophy (and Vice Versa).
Science.gov (United States)
Vandenberghe, Frédéric
2017-11-01
In this article, I want to make an attempt to reconnect sociology to moral philosophy and moral philosophy to sociology. The thesis I want to defend is that sociology continues by other means the venerable tradition of practical and moral philosophy. Like its forebears, it stands and falls with a defense of "practical wisdom" (Aristotle) and "practical reason" (Kant). The development of a moral sociology presupposes, however, that one recognizes and rejects Max Weber's theory of axiological neutrality as an extremist position and that one carefully articulates prescriptive and descriptive, internal and external, as well as observer and actor positions. © 2017 Canadian Sociological Association/La Société canadienne de sociologie.
5. Lynch, Urry and city marketing: Taking advantage of the city as a built and graphic image
NARCIS (Netherlands)
Hospers, G-J.
2009-01-01
City marketing is usually addressed from the perspective of marketing theory. This article follows an alternative approach by exploring city marketing from the viewpoint of urban planning and the sociology of tourism. In his classic ‘The Image of the City’ (1960), planner Kevin Lynch found that
6. The Sociology and Entrenchment. A Cystic Fibrosis Test for Everyone?
DEFF Research Database (Denmark)
Koch, Lene; Stemerding, Dirk
1994-01-01
Socialmedicine, genetic screening, cystic fibrosis, ethics, political regulation, sociology of technology......Socialmedicine, genetic screening, cystic fibrosis, ethics, political regulation, sociology of technology...
7. On the Political Sociology of the Imperial Greek City
Directory of Open Access Journals (Sweden)
Arjan Zuiderhoek
2010-11-01
Full Text Available Elements of oligarchy, democracy, and hierarchy coexisted in the polis of Roman times, and the survival of the democratic element may reflect the prospering of small businessmen with their own political interests.
8. Principles of Sociology in Systems Engineering
Science.gov (United States)
Watson, Michael D.; Andrews, James G.; Larsen, Jordan A.
2017-01-01
Systems engineering involves both the integration of the system and the integration of the disciplines which develop and operate the system. Integrating the disciplines is a sociological effort to bring together different groups, often with different terminology, to achieve a common goal, the system. The focus for the systems engineer is information flow through the organization, between the disciplines, to ensure the system is developed and operated with all relevant information informing system decisions. Robert K. Merton studied the sociological principles of the sciences and the sociological principles he developed apply to systems engineering. Concepts such as specification of ignorance, common terminology, opportunity structures, role-sets, and the reclama (reconsideration) process are all important sociological approaches that should be employed by the systems engineer. In bringing the disciplines together, the systems engineer must also be wary of social ambivalence, social anomie, social dysfunction, insider-outsider behavior, unintended consequences, and the self-fulfilling prophecy. These sociological principles provide the systems engineer with key approaches to manage the information flow through the organization as the disciplines are integrated and share their information. This also helps identify key sociological barriers to information flow through the organization. This paper will discuss this theoretical basis for the application of sociological principles to systems engineering.
9. Metaphor of society (a sociological essay
Directory of Open Access Journals (Sweden)
2014-11-01
Full Text Available The essay by Academician G.V. Osipov, who is the patriarch of Russian sociology, is dedicated to one of the most cognitive topics of modern sociology – identification of sociological metaphor as such and its application in research projects. This topic is avant-garde for the world sociological thought, and in Russia such kind of research is making its first steps. However, its future importance is difficult to overestimate. Sociological metaphor, if a methodology for its application is developed, can provide scientists with qualitatively new synthetic research tools. It can also bring together scientific structures and artifacts on the space of interdisciplinary and inter-subject borderland and give them qualitatively new intellectual and sensuous (system and mental technological capabilities for learning the surrounding world. The advantage of the following essay can be found in the fact that it is based on the objective analysis of the real embodiment of social metaphor in the work of art – a pictorial triptych “The Mystery of the 21st Century”. This is the first such experience in domestic sociological and artistic-painting practice. The authors of the final product are a scientist of great scientific and life experience and a young artist, who received in-depth sociological training and defended his Ph.D. in Sociology dissertation. But the main result of their collaboration is a product that combines scientific (sociological knowledge and insight and intuitive-creative artistic perception in a qualitatively new perception of the world and world outlook
10. Inner Consciousness Tindakan Nabi
Directory of Open Access Journals (Sweden)
Moh. Helmi Umam
2015-09-01
Full Text Available The article is written to examine deeds and actions of the Prophet Muhammad (peace be upon him within inner consciousness analysis of Husserl’s phenomenology. The article is formulated to explore the significance of phenomenology of religious study, Prophet’s deeds as well as his inner consciousness, and inner consciousness analysis of Prophet’s deeds. This article is written using phenomenological method, i.e. a comprehensive interpretation about the source of information or object’s phenomenon as long as it can be traced. Inner consciousness of Prophet’s actions sees that his deeds in deciding important religious pronouncements were results of long-term memory based on divine and social argumentations, which have came into Prophet’s consciousness as a human.
11. SOCIOLOGICAL MEDIA: MAXIMIZING STUDENT INTEREST IN QUANTITATIVE METHODS VIA COLLABORATIVE USE OF DIGITAL MEDIA
Directory of Open Access Journals (Sweden)
Frederick T. Tucker
2016-10-01
Full Text Available College sociology lecturers are tasked with inspiring student interest in quantitative methods despite widespread student anxiety about the subject, and a tendency for students to relieve classroom anxiety through habitual web browsing. In this paper, the author details the results of a pedagogical program whereby students at a New York City community college used industry-standard software to design, conduct, and analyze sociological surveys of one another, with the aim of inspiring student interest in quantitative methods and enhancing technical literacy. A chi-square test of independence was performed to determine the effect of the pedagogical process on the students’ ability to discuss sociological methods unrelated to their surveys in their final papers, compared with the author’s students from the previous semester who did not undergo the pedagogical program. The relation between these variables was significant, χ 2(3, N=36 = 9.8, p = .02. Findings suggest that community college students, under lecturer supervision, with minimal prior statistical knowledge, and access to digital media can collaborate in small groups to create and conduct sociological surveys, and discuss methods and results in limited classroom time. College sociology lecturers, instead of combatting student desire to use digital media, should harness this desire to advance student mastery of quantitative methods.
12. First Contact: Teaching and Learning in Introductory Sociology
Science.gov (United States)
Greenwood, Nancy A.
2011-01-01
The Introduction to Sociology course is usually the first contact that students have with the discipline of sociology. This course can determine whether students take other sociology courses or learn to use sociology in their lives as adults and citizens. "First Contact" identifies important issues facing instructors in introducing students to the…
13. Social inequality: philosophical and sociological reflection
Directory of Open Access Journals (Sweden)
A. Sh. Victorov
2014-01-01
Full Text Available Social inequality is the phenomena that is hypothetically the base for first human communities genesis. Modern model for capitalist society as market relations form fails to satisfy the needs of society’s social development, and strongly requires to create new social knowledge structure and new approach for inequality sociology theory development. Our study conceptual logic comprises routine, philosophic and ideological reflexions analysis to create new social inequality definition in the context of new sociologic knowledge structure. Social inequality is the one of key problems in global sociology; the need is obvious to extract social inequality into separate discipline. Inequality sociology target is the decision of theoretical and practical problems in the formation of comprehensive knowledge about inequality phenomena in modern community, and in the development of common and specialized theoretical-methodological base for inequality study.
14. Economic Sociology and Economics of Convention
DEFF Research Database (Denmark)
Jagd, Søren
This paper is part of a larger exploration of the French Economics of Convention tradition. The aim of the paper is to explore potential themes of common interest to economic sociology and Economics of Conventions. The paper is in two parts. First, I summarise the main theoretical features of EC...... the institutional framework of social action. Second, I explore two issues raised by economics of conventions that may be particularly important to consider for economic sociology. The first issue is the explicit exploration of the consequences of a plurality of forms of justification suggested by Luc Boltanski...... and Laurent Thévenot in ‘économie de la grandeur’. This perspective has already been taken up in economic sociology in David Stark’s notion of a ‘Sociology of Worth’. The second issue, recently suggested by André Orléan, is the need to denaturalise economic theory and economic action to demonstrate the social...
15. Sociological Discourse(s) on Freedom
DEFF Research Database (Denmark)
Bertilsson, Margareta
The concept of freedom is often thought of as antithetical to sociology. The discipline is more prone to detect and unveil forms of unfreedom, as Zygmunt Bauman (1988) has pointed out. The question remains if any academic discipline, however, including sociology can do away with the concept...... of freedom al together! In matters of science, the problem of determinism vs. chance and spontaneity is essential. Hence, freedom, in one sense or the other, is necessarily at bottom also of sociological discourse. This text is an attempt to map the predominant forms of freedom found in sociological...... discourses. While starting out with the classic liberal concept informing theories of modernity followed by the various critiques directed against liberalism, not the least the most recently occurring (Lyotard, Agamben), the aim here is to spot possible trajectories in our comprehension of freedom, also...
16. The sociology of innovation in modern astronomy
International Nuclear Information System (INIS)
Edge, D.
1977-01-01
This paper describes some of the main features of the development of astronomy since 1945, stressing sociological factors, and drawing examples mainly from the history of radio astronomy. Particular attention is given to aspects which appear to distinguish astronomy from other recently-studied sciences - notably, the prevalence of serendipitous discoveries, and the lack of any general resistance from the 'parent' discipline. The work of Kuhn and Hagstrom is used to illuminate these features, and also to indicate how a sociological analysis can be advanced of individual research decisions, and of the nature of disputes within science. Common misconceptions about the nature and scope of sociology are briefly discussed; in particular, it is emphasized that the kind of sociology of science under discussion cannot be normative. (author)
17. The Challenge of Training in Applied Sociology.
Science.gov (United States)
Johnson, Doyle Paul; And Others
1987-01-01
Explores the challenge of expanding nonacademic employment opportunities for sociologists and training sociology students for such employment. Suggests several interrelated strategies for these students that address issues of marketing and public relations as well as curriculum revision. (Author/BSR)
18. The Reflexive Principle of Sociological Theorization
Directory of Open Access Journals (Sweden)
R T Ubaidullayeva
2013-12-01
Full Text Available The article attempts to describe the reflexive principle in theory-making, which integrates the basic modern methodological paradigms and lays the foundation for the development of sociology. On the basis of the theoretical ideas of P. Bourdieu, A. Giddens and P. Ricoeur the author defines the concept of social reflexion and reveals its peculiarities in sociology as compared to reflexion in philosophy. According to the author, the fulfillment of reflexive functions in sociology is connected with the task of analyzing the complex structure of the polysemantic object, considering the specific quality of the subjects and their various trends of development. The presence of the poles — objectivity-subjectivity, rationality-irrationality, consciousness-unconsciousness etc, requires a reproduction of the dichotomies engendering them in social life and development of cognitive methods for their study in sociology.
19. EDITORIAL: | Oloyede | African Sociological Review / Revue ...
African Journals Online (AJOL)
20. African Sociological Review / Revue Africaine de Sociologie
African Journals Online (AJOL)
1. African Sociological Review / Revue Africaine de Sociologie
African Journals Online (AJOL)
2. Book Review | Oloyede | African Sociological Review / Revue ...
African Journals Online (AJOL)
3. Editorial | Oloyede | African Sociological Review / Revue Africaine ...
African Journals Online (AJOL)
4. African Sociological Review / Revue Africaine de Sociologie
African Journals Online (AJOL)
5. Editorial | Oloyede | African Sociological Review / Revue Africaine ...
African Journals Online (AJOL)
6. Third Worldism | Nash | African Sociological Review / Revue ...
African Journals Online (AJOL)
7. Editorial | Oloyede | African Sociological Review / Revue Africaine ...
African Journals Online (AJOL)
8. Brazilian environmental sociology: a provisional review
Directory of Open Access Journals (Sweden)
Ferreira Leila da Costa
2002-01-01
Full Text Available The article aims firstly at the reconstitution and analysis of history within the scope of international environmental sociology situated in the context of contemporary sociology. It also discusses - from the standpoint of literature (Buttel, Dunlap, Hanning, among others - its theoretical-methodological and institutional aspects as well in order to understand the obstacles encountered to legitimate and consolidate a set of problems which, until recently, were not dealt with by social sciences. Secondly, it analyses the Brazilian case. Environmental sociology in Brazil is strongly influenced by American empirical sociology, the precursor of the institutionalization process for the themes. On the other hand, further analysis of this case is relevant to understand the relationship between the scientific sphere, and the creation of environmental policies and social movements.
9. Knowledge networking on Sociology: network analysis of blogs, YouTube videos and tweets about Sociology
Directory of Open Access Journals (Sweden)
Julián Cárdenas
2017-06-01
10. Sociological explanations of economic growth.
Science.gov (United States)
Marsh, R M
1988-01-01
Even if questions of how resources are distributed within and between societies are the main concern, it is necessary to continue to grapple with the issue of the causes of economic growth since economic growth and level of development continue to be among the most important causes of inequality, poverty, unemployment, and the quality of life. This paper's dependent variable is the economic growth rate of 55 less developed countries (LDCs) over 2 time periods. 1970-78 and 1965-84. The causal model consists of control variables--level of development and domestic investment in 1965--and a variety of independent variables drawn from major sociological theories of economic growth published during the last 3 decades. Multiple regression analysis shows that, net of the effects of the 2 control variables, the variables which have the strongest effect on economic growth are: 1) direct foreign investment, which has a negative effect, 2) the proportion of the population in military service, and 3) the primary school enrollment ratio, both of which have positive effects on economic growth. On the other hand, variables drawn from some theories receive no empirical support. The mass media of communications, ethnolinguistic heterogeneity, democracy and human rights, income inequality, and state-centric theory's key variable, state strength, all fail to show any significant impact on economic growth rates when the control variables and the significant independent variables are held constant. The theoretical implications of these findings are discussed.
11. Towards a Sociological Model of Corporate Entrepreneurship
OpenAIRE
Dingsdale, Simon
2008-01-01
The primary purpose of this study is to establish a sociological grounding for the field of Corporate Entrepreneurship (CE) through the development of an organic sociological model. I argue that there are four key problems underlying the CE literature 1) no unifying theoretical base 2) no multi-dimensional, organic model 3) no multi-dimensional analysis 3) no easily implementable model and 4) no identification of critical antecedents. Scholars have failed to understand that without a unifyin...
12. Socialkonstruktivismer i klassisk og moderne sociologi
DEFF Research Database (Denmark)
Rasborg, Klaus
2004-01-01
En videnskabsteoretisk diskussion af socialkonstruktivismens genealogi, samt af en række fremtrædende socialkonstruktivistiske positioner i klassisk og moderne sociologi (Marx, Weber, Durkheim, Berger & Luckmann, Goffman og Bourdieu)......En videnskabsteoretisk diskussion af socialkonstruktivismens genealogi, samt af en række fremtrædende socialkonstruktivistiske positioner i klassisk og moderne sociologi (Marx, Weber, Durkheim, Berger & Luckmann, Goffman og Bourdieu)...
13. Remembering a sociology of Human Rights
OpenAIRE
Levy, Daniel; Sznaider, Natan
2014-01-01
A sociology of human rights sounds almost like a contradiction in terms. Sociology is about social groups, about particular experiences, about how people, embedded in space and time, make sense of their lives and give meaning to their world. It deals with power and interest and the social bases of our experiences. On the other hand, human rights are about human beings in general, without temporal or spatial references, not about groups and their boundaries. Human rights are about humanity, lo...
14. The Impact of Feminism on Sociology
OpenAIRE
Sylvia Walby
2011-01-01
The paper investigates the impact of feminism on British sociology over the last 60 years. It focuses on changes in the intellectual content of the discipline, including epistemology, methodology, theory, concepts and the fields of economy, polity, violence and civil society. It situates these changes in the context of changes in gendered organisation of sociology, the rise of women's/gender studies, the ecology of social sciences and societal changes, especially the transformation of the gen...
15. 500 Cities: City Boundaries
Data.gov (United States)
U.S. Department of Health & Human Services — This city boundary shapefile was extracted from Esri Data and Maps for ArcGIS 2014 - U.S. Populated Place Areas. This shapefile can be joined to 500 Cities...
16. The Institution of Sociological Theory in Canada.
Science.gov (United States)
Guzman, Cinthya; Silver, Daniel
2018-02-01
Using theory syllabi and departmental data collected for three academic years, this paper investigates the institutional practice of theory in sociology departments across Canada. In particular, it examines the position of theory within the sociological curriculum, and how this varies among universities. Taken together, our analyses indicate that theory remains deeply institutionalized at the core of sociological education and Canadian sociologists' self-understanding; that theorists as a whole show some coherence in how they define themselves, but differ in various ways, especially along lines of region, intellectual background, and gender; that despite these differences, the classical versus contemporary heuristic largely cuts across these divides, as does the strongly ingrained position of a small group of European authors as classics of the discipline as a whole. Nevertheless, who is a classic remains an unsettled question, alternatives to the "classical versus contemporary" heuristic do exist, and theorists' syllabi reveal diverse "others" as potential candidates. Our findings show that the field of sociology is neither marked by universal agreement nor by absolute division when it comes to its theoretical underpinnings. To the extent that they reveal a unified field, the findings suggest that unity lies more in a distinctive form than in a distinctive content, which defines the space and structure of the field of sociology. © 2018 Canadian Sociological Association/La Société canadienne de sociologie.
17. On the nature and sociology of bioethics.
Science.gov (United States)
Sheehan, Mark; Dunn, Michael
2013-03-01
Much has been written in the last decade about how we should understand the value of the sociology of bioethics. Increasingly the value of the sociology of bioethics is interpreted by its advocates directly in terms of its relationship to bioethics. It is claimed that the sociology of bioethics (and related disciplinary approaches) should be seen as an important component of work in bioethics. In this paper we wish to examine whether, and how, the sociology of bioethics can be defended as a valid and justified research activity, in the context of debates about the nature of bioethics. We begin by presenting and arguing for an account of bioethics that does justice to the content of the field, the range of questions that belong within this field, and the justificatory standards (and methodological orientations) that can provide convincing answers to these questions. We then consider the role of sociology in bioethics and show how and under what conditions it can contribute to answering questions within bioethics. In the final section, we return to the sociology of bioethics to show that it can make only a limited contribution to the field.
18. Practical Application of Sociology in Systems Engineering
Science.gov (United States)
Watson, Michael D.; Andrews, James G.; Eckley, Jeri Cassel; Culver, Michael L.
2017-01-01
Systems engineering involves both the integration of the system and the integration of the disciplines which develop and operate the system. Integrating the disciplines is a sociological effort to bring together different groups, who often have different terminology, to achieve a common goal, the system. The focus for the systems engineer is information flow through the organization, between the disciplines, to ensure the system is developed and operated will all relevant information informing system decisions. The practical application of the sociology in systems engineering brings in various organizational development concepts including the principles of planned renegotiation and the application of principles to address information barriers created by organizational culture. Concepts such as specification of ignorance, consistent terminology, opportunity structures, role-sets, and the reclama (reconsideration) process are all important sociological approaches that help address the organizational social structure (culture). In bringing the disciplines together, the systems engineer must also be wary of social ambivalence, social anomie, social dysfunction, and insider-outsider behavior. Unintended consequences can result when these social issues are present. These issues can occur when localized subcultures shift from the overarching organizational culture, or when the organizational culture prevents achievement of system goals. These sociological principles provide the systems engineer with key approaches to manage the information flow through the organization as the disciplines are integrated and share their information and provides key sociological barriers to information flow through the organization. This paper will discuss the practical application of sociological principles to systems engineering.
19. Political sociology of human rights
Directory of Open Access Journals (Sweden)
Mahdi Kazemi
2014-11-01
Full Text Available The dominant approach in the field of human rights is Legal attitude. Legal attitude more than anything else on the identification and recognition of human rights by the government is focused. At the same time, governments are the biggest violators of human rights norms. Despite the gap between the legal obligations of states and the real world, legal analysis of this gap is not possible. Therefore, in the era of inflation of rights, according to Louis Henkin , transition needs based approach to the protection of human rights is justified. Social sciences, especially political sociology may be, to identify obstacles to the realization of human rights in different societies and operate it is used. Since the main subject of political sociology "explores the relationship between state and society" is, knowledge can be produced in the field of political sociology in understanding the inability of governments establishing human rights norms and effective ways to fix it. Therefore, it can be said that human rights political sociology focus on: how to advance the state of human rights in a society and its institutionalization and consolidation within all relationships and political processes. رهیافت مسلط در حوزه مطالعات حقوق بشر، نگرش حقوقی است.نگرش حقوقی بیش از هرچیز بر شناسایی و به رسمیت شناختن حقوق بشر توسط دولتها متمرکز است.در عین حال، دولتها خود بزرگترین ناقضین هنجارهای حقوق بشری میباشند. با وجود شکاف میان تعهدات حقوقی دولتها و جهان واقعی، تحلیل حقوقی از این شکاف ممکن نیست. لذا، در عصر تورم حقوق به تعبیر هنکین، نیازمند گذار از رهیافت مبتنی بر توجیه به حفاظت از حقوق بشر هستیم. علوم اجتماعی بویژه جامعه
20. "It's Not Rocket Science!": High School Sociology Teachers' Conceptions of Sociology
Science.gov (United States)
DeCesare, Michael
2006-01-01
Since academic sociology's birth in this country, sociologists have not been shy about publicly praising and ridiculing the discipline. Though sociologists have been the primary participants in the seemingly endless debates about sociology's proper subject matter, methods, and purpose, there is another group that has also struggled over the past…
1. Sociology of the Prison Classroom: Marginalized Identities and Sociological Imaginations behind Bars
Science.gov (United States)
Parrotta, Kylie L.; Thompson, Gretchen H.
2011-01-01
The authors use sociology of the college classroom to analyze their experiences as feminists teaching sociology courses in the "unconventional setting" of prison. Reflective writing was used to chronicle experiences in the classes. They apply the concepts of doing gender, interaction order, and emotion work to the prison classroom. Based on their…
2. Why, Where, and How to Infuse the Atlanta Sociological Laboratory into the Sociology Curriculum
Science.gov (United States)
Wright, Earl, II
2012-01-01
The Atlanta Sociological Laboratory is the moniker bestowed on scholars engaged in sociological research at Atlanta University between 1895 and 1924. Under the leadership of W. E. B. Du Bois, 1897-1914, this school made substantive yet marginalized contributions to the discipline. Its accomplishments include, but are not limited to, its…
3. [From sociology in medicine to the sociology of collective health: contributions toward a necessary reflexivity].
Science.gov (United States)
Castro, Roberto
2016-03-01
This text looks at the difference between sociology in medicine (collaborator of health institutions) and the sociology of medicine (independent of health institutions). If consistent, sociology in medicine should become a sociology of medicine. As an example, it is shown how the study of the social determinants of health and illness begins by assuming non-problematically the ontological reality of health and illness, but ends up problematizing the very concept of health-disease, demonstrating that the study of health determinants also requires the study of the determinants of the social construction of disease. The urgent necessity of objectifying collective health itself is argued. By applying sociological tools we can examine the so-called objective factors in the determination of health and disease, the socially constructed nature of these categories of knowledge, and the struggles and power relations that determine whether or not such categories are viable.
4. The Inner Urban Edge
Science.gov (United States)
Ferebee, Ann; Carpenter, Edward K.
1974-01-01
In this article, renewal of the inner urban edge is discussed. Norfolk (Virginia) is attempting to blur the difference between old and new neighbor hoods through zoning and architectural controls. Cincinnati (Ohio) is developing an environmentally sound hillside design. Reading (Pennsylvania) is utilizing old railyards for greenbelts of hiking and…
5. The Inner Circle Revisited
DEFF Research Database (Denmark)
Grau Larsen, Anton; Ellersgaard, Christoph
2018-01-01
in social networks, we identify a cohesive core group of 171 individuals within a corporate elite of 6154 board members of the top 1037 Danish corporations. A high degree of social homogeneity in gender, social background, education and career position underlines the cohesion of the inner circle. By mapping...
6. [Pierre Bourdieu: sociology as a "symbolic revolution"].
Science.gov (United States)
Suaud, Charles
2014-03-01
The article combines two objectives: understand the genesis and development of the sociology of Bourdieu in connection with his social and intellectual positioning. The sociology of Bourdieu is a theory of Action which reconciles the double requirement of objectification and taking account of the practical logic bound by social agents. From the character both objective and subjective of social space, he analyzes how different institutions (firstly School) are doing that mental structures match the objective structures of society. By making acceptable reality and registering it in the body, these instances contribute to reproduce social divisions and participate in the work of domination. Gradually, Bourdieu develops a general theory about Power, which leads to a sociology of State. But he refuses any sociological fatalism. Because he perceived homologies between the sociologist and the artist facing the social order, each in their own way, he devoted two researches to Flaubert and Manet, seized in the same enterprise of aesthetic subversion he described as a 'symbolic revolution'. In many aspects, the sociology of Bourdieu opens ways of looking for an objectification of caregivers and their practices.
7. 'Facework', Flow and the City
DEFF Research Database (Denmark)
Jensen, Ole B.
2006-01-01
This paper contains a re-reading of Simmel and Goffman with an eye to the mobility practices of the contemporary city. The paper offers a ‘new’ perspective on mobility in the contemporary city by re-reading two sociological ‘classics’ as there is a need to conceptualise the everyday level of flow...... and mobility in the midst of an intellectual climate dominated by grand theories of networks and globalisation. In the re-reading of Simmel and Goffman, the aim is to reach an understanding of how contemporary material mobility flows and symbolic orders and meanings are produced and re-produced. You may argue...
8. The sociological knowledge and problematic behaviors’ prevention
Directory of Open Access Journals (Sweden)
Aida Serjanaj
2017-03-01
Full Text Available This paper aims to highlight the importance of sociology knowledge in students attending teaching Master Program, specialists in education, experienced teachers, as well as high school graduates who study sociology in high school. The issues discussed involve not only the role of teacher on recording and straightening such problematic behaviors but even the ways of changing the situation on the future. Phenomena such as: culture, subculture, ethnicity, religion, race and gender diversity, prejudices and discrimination which derive by these kinds of diversities; inequality of social strata, the understanding of social role, cultural norms practicing and their respecting are present in our schools environment. These are reasons why teachers and students must have information about above-mentioned phenomena. Ministry of Education and Sport must add Sociology as a subject of core curricula of high school and teachers programs’ studies.
9. Introduction: why a Sociology of Pandemics?
Science.gov (United States)
Dingwall, Robert; Hoffman, Lily M; Staniland, Karen
2013-02-01
Infectious disease has re-emerged as a public health threat in an increasingly globalised era, adding trans-national actors to traditional national and local government actors. This special issue showcases new sociological work in response to this challenge. The contributors have investigated the social construction of new and re-emerging diseases; the development of surveillance systems, public health governance; the impact of scientific/technical modalities on uncertainty and risk, the interplay of infectious disease, public health and national security concerns, and public and media responses. The case studies range broadly across North America, Europe and Asia and define new agendas for medical sociologists and public health policymakers. © 2012 The Authors. Sociology of Health & Illness © 2012 Foundation for the Sociology of Health & Illness/Blackwell Publishing Ltd.
10. Desperately seeking sociology: nursing student perceptions of sociology on nursing courses.
Science.gov (United States)
Edgley, Alison; Timmons, Stephen; Crosbie, Brian
2009-01-01
This paper will present the findings of a qualitative study exploring the perceptions of students confronted by a requirement to learn sociology within a nursing curriculum. Those teaching sociology have a variety of explanations (more or less desperate), seeking to justify its place on the nursing curriculum. While there may be no resolution to the debate, the dispute thus far, has largely been between sociology and nursing academics. Absent from this debate are the voices of students 'required' to learn both nursing and sociology. What do students make of this contested territory? When students are trying to learn their trade, and know how to practice safely and efficaciously what do they make of the sociological imagination? How realistic is it to expect students to grasp both the concrete and practical with the imaginative and critical? Findings from this qualitative, focus group study suggest that students do indeed find learning sociology within a nursing curriculum "unsettling". It would seem that students cope in a number of ways. They fragment and compartmentalise knowledge(s); they privilege the interception of experiential learning on the path between theory and practice; and yet they appear to employ sociological understanding to account for nursing's gendered and developing professional status.
11. 内蒙古赤峰市兴隆沟聚落遗址2002～2003年的发掘%2002-2003 Excavation on the Settlement-site at Xinglonggou in Chifeng City, Inner Mongolia
Institute of Scientific and Technical Information of China (English)
中国社会科学院考古研究所内蒙古第一工作队
2004-01-01
In 2002- 2003, the First Inner Mongolian Archaeological Team, IA, CASS, carried out two seasons of excavation on the Xinglonggou site. The work resulted in the confirmation of the first locality as a large-sized settlement of the middle Xinglongwa culture (8000-7500 BP). The significant findings in dwelling form, settlement layout, burial custom, primitive religion, economic formation and environmental archaeology represent a new type in the Xinglongwa culture. The second locality is left over from a small-sized ditch-surrounded settlement of the Hongshan culture (5500-5000 BP). Its discovery made up the gap of late Hongshan Culture sites in the prehistoric data. The third locality remains of a small-sized ditch-surrounded settlement of the Lower Xiajiadian culture (4000-3500BP), which offers new material for studying the civilizing course and early state form of the West Liaohe River valley. The excavation of the Xinglonggou site will forcefully promote the deep-going study of prehistoric archaeological cultures in Northeast China and exert active influence upon the research on Sino-Japanese cultural relations in prehistoric times.
12. Sociology of Knowledge Perspective on Entrepreneurship
DEFF Research Database (Denmark)
Turcan, Romeo V.
2018-01-01
This chapter addresses one of the enduring questions in sociology of knowledge: how is it possible that subjective meanings become objective facticities? It adopts this question to understand the entrepreneurship phenomenon, and, more specifically, to understand how new business or venture ideas...... and new sectors or industries (as subjective meanings) are legitimated and institutionalized (become socially established as reality). Building on Berger and Luckmann’s Treatise in the Sociology of Knowledge, the chapter suggests an alternative order objectivation of meaning to understand entrepreneurship...
13. Does infant cognition research undermine sociological theory?
DEFF Research Database (Denmark)
Bjerre, Jørn
2012-01-01
This article discusses how the results of infant research challenge the assumptions of the classical sciences of social behaviour. According to A.J. Bergesen, the findings of infant research invalidate Durkheim's theory of mental categories, thus requiring a re-theorizing of sociology. This article...... argues that Bergesen's reading of Emile Durkheim is incorrect, and his review of the infant research in fact invalidates his argument. Reviewing the assumptions of sociology in the light of the findings of infant research, it is argued that the real challenge is to formulate a research strategy...
14. The ATLAS Inner Detector
CERN Document Server
Gray, HM; The ATLAS collaboration
2012-01-01
The ATLAS experiment at the LHC is equipped with a charged particle tracking system, the Inner Detector, built on three subdetectors, which provide high precision measurements made from a fine detector granularity. The Pixel and microstrip (SCT) subdetectors, which use the silicon technology, are complemented with the Transition Radiation Tracker. Since the LHC startup in 2009, the ATLAS inner tracker has played a central role in many ATLAS physics analyses. Rapid improvements in the calibration and alignment of the detector allowed it to reach nearly the nominal performance in the timespan of a few months. The tracking performance proved to be stable as the LHC luminosity increased by five orders of magnitude during the 2010 proton run, New developments in the offline reconstruction for the 2011 run will improve the tracking performance in high pile-up conditions as well as in highly boosted jets will be discussed.
15. Earth's inner core: Innermost inner core or hemispherical variations?
NARCIS (Netherlands)
Lythgoe, K. H.; Deuss, A.|info:eu-repo/dai/nl/412396610; Rudge, J. F.; Neufeld, J. A.
2014-01-01
The structure of Earth's deep inner core has important implications for core evolution, since it is thought to be related to the early stages of core formation. Previous studies have suggested that there exists an innermost inner core with distinct anisotropy relative to the rest of the inner core.
16. African Sociological Review / Revue Africaine de Sociologie: About ...
African Journals Online (AJOL)
17. The Correlation of Sociology, Historical and Dialectical Materialism - USSR
National Research Council Canada - National Science Library
NARSKIY, I
1960-01-01
.... 5, 1957, has brought many responses. This is because the article touched not only on the question of the correction of sociology and historical materialism, but inevitably raised the problem of the correction of sociology...
18. The sociology of medical screening: past, present and future.
Science.gov (United States)
Armstrong, Natalie; Eborall, Helen
2012-02-01
Medical screening raises fundamental issues for sociological inquiry, but at present a well-developed sociology of medical screening is lacking. This special issue on the sociology of screening brings together an exciting collection of new work that tackles medical screening from a variety of theoretical and methodological approaches. In this opening paper, we begin by explaining what we mean by screening, and why we believe screening merits sociological attention. Secondly, we reflect on the sociology of screening to date and provide an introduction for those new to this area. We then provide an overview of the papers in this collection, highlighting links and contrasts between papers. We conclude by reflecting on sociology's potential contribution to wider debates about screening, and propose future research directions. © 2011 The Authors. Sociology of Health & Illness © 2011 Foundation for the Sociology of Health & Illness/Blackwell Publishing Ltd.
19. Scientific Discovery in Deep Social Space: Sociology without Borders
OpenAIRE
Joseph Michalski
2008-01-01
Globalization affords an excellent opportunity to develop a genuinely universal, scientific sociology. In recent decades the politicization of the discipline has undermined the central mission of sociology: scientific discovery and explanation. The paper identifies several intellectual shifts that will facilitate the expansion and communication of such a science in an emerging global village of sociological analysts: 1) breaking with classical sociology to build upon innovative theoretical id...
20. The Continuation of the Dialectic in Sociology
NARCIS (Netherlands)
Ossewaarde, Marinus R.R.
2010-01-01
A rapidly changing ‘society’ that requires ‘new units of analysis’, ‘new roles for sociology’, and new democratic commitment to ‘the publics’ has implications for the identity and calling of sociology. In this so-called ‘identity crisis’, some sociologists have introduced the so-called ‘after
1. Time for creative integration in medical sociology.
Science.gov (United States)
Levine, S
1995-01-01
The burgeoning of medical sociology has sometimes been accompanied by unfortunate parochialism and the presence of opposing intellectual camps that ignore and even impugn each other's work. We have lost opportunities to achieve creative discourse and integration of different perspectives, methods, and findings. At this stage we should consider how we can foster creative integration within our field.
2. Sociology of religion in the Netherlands
NARCIS (Netherlands)
de Groot, Kees; Sengers, Erik; Blasi, Anthony J.; Giordan, Giuseppe
In 1960, the Dutch journal of the Catholic Social-Ecclesial Institute (Kaski) Sociaal Kompas became Social Compass. This shift rounded off a period now considered as the heyday of Dutch sociology of religion. Ironically, in those years, Catholic sociologists in particular contested the legitimacy of
3. New Biological Sciences, Sociology and Education
Science.gov (United States)
Youdell, Deborah
2016-01-01
Since the Human Genome Project mapped the gene sequence, new biological sciences have been generating a raft of new knowledges about the mechanisms and functions of the molecular body. One area of work that has particular potential to speak to sociology of education, is the emerging field of epigenetics. Epigenetics moves away from the mapped…
4. Human Right for Fair Wage: sociological aspect
Directory of Open Access Journals (Sweden)
Ponomareva T. M.
2012-05-01
Full Text Available The article summarizes the results of sociological research devoted to the analysis of the fair wage problem. The authors analyze the dynamics of labor load and the level of wages in the economic market conditions taking as an example the Omsk Region
5. The Sociology of Family Health. A Bibliography.
Science.gov (United States)
Jumba-Masagazi, A. H. K., Comp.
This unannotated bibliography is on man, his family, the society he makes and lives in, and his health. It is about man and his East African environment. It attempts to bring together both the applied and social sciences as they affect the family. Among the disciplines drawn from are: anthropology, sociology, medicine, religion, economics, labor…
6. Teaching the Sociology of Gender and Work
Science.gov (United States)
Giuffre, Patti; Anderson, Cynthia; Bird, Sharon
2008-01-01
This paper describes two teaching strategies from our workshop, "Teaching the Sociology of Gender and Work," that can help students understand the mechanisms and consequences of workplace gender inequality at the macro- and micro-levels. Cynthia Anderson's class project uses wage and sex composition data that allows students to learn actively how…
7. introductory concepts on sociological jurisprudence: jhering ...
African Journals Online (AJOL)
eliasn
sociological theory whose main and pervasive message is that “law is a social .... content of law is infinitely varied and relative to the different societies. There is thus ... All legal principles for Jhering can be reduced to the security of condition of.
8. Sociology, environment and health: a materialist approach.
Science.gov (United States)
Fox, N J; Alldred, P
2016-12-01
This paper reviews the sociology of environment and health and makes the case for a postanthropocentric approach based on new materialist theory. This perspective fully incorporates humans and their health into 'the environment', and in place of human-centred concerns considers the forces that constrain or enhance environmental capacities. This is not an empirical study. The paper uses a hypothetical vignette concerning child health and air pollution to explore the new materialist model advocated in the paper. This paper used sociological analysis. A new materialist and postanthropocentric sociology of environment and health are possible. This radically reconfigures both sociological theory and its application to research and associated policies on health and the environment. Theoretically, human health is rethought as one among a number of capacities emerging from humans interactions with the social and natural world. Practically, the focus of intervention and policy shifts towards fostering social and natural interactions that enhance environmental (and in the process, human) potentiality. This approach to research and policy development has relevance for public health practice and policy. Copyright © 2016 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.
9. Regression Analysis and the Sociological Imagination
Science.gov (United States)
De Maio, Fernando
2014-01-01
Regression analysis is an important aspect of most introductory statistics courses in sociology but is often presented in contexts divorced from the central concerns that bring students into the discipline. Consequently, we present five lesson ideas that emerge from a regression analysis of income inequality and mortality in the USA and Canada.
10. On the New Approach in Sociological Education
Science.gov (United States)
Russian Education and Society, 2012
2012-01-01
A roundtable was held in April 2010, by correspondence and with participants in attendance; it was organized by the editorial board of "Sotsiologicheskie issledovaniia" jointly with the faculty of sociology of the Russian State University of the Humanities [RGGU]. The focus of the proceedings was a discussion (taking account of…
11. The Sociological Imagination and Social Responsibility
Science.gov (United States)
Hironimus-Wendt, Robert J.; Wallace, Lora Ebert
2009-01-01
In this paper, we maintain that sociologists should deliberately teach social responsibility as a means of fulfilling the promise that C. Wright Mills envisioned. A key aspect of the sociological imagination includes a sense of social responsibility, but that aspect is best learned through a combination of experience and academic knowledge.…
12. Teaching the Vietnam War: A Sociological Approach.
Science.gov (United States)
Starr, Jerold M.
1995-01-01
Maintains that, because of its importance in modern U.S. history, over 300 college courses are taught on the Vietnam War. Asserts that studying the war helps students develop critical thinking skills needed for citizenship. Describes the texts, formats, and assignments used in a college sociology course on the Vietnam War. (CFR)
13. How Sociology Texts Address Gun Control
Science.gov (United States)
Tonso, William R.
2004-01-01
William R. Tonso has chosen an issue that he knows something about to examine how sociology textbooks address controversy. Appealing for gun control is fashionable, but it is at odds with a fondness that ordinary Americans have for their firearms--one that is supported by a growing body of research on deterrence to crime. There are two sides to…
14. One Hundred Years of Sociological Solitude?
OpenAIRE
Rumbaut, RG
2005-01-01
On the occasion of the American Sociological Association's centennial, The Chronicle asked seven sociologists to discuss what attracted them to the field, what they consider to be the discipline's fortes and failings, and where they'd like to see it go from here.
15. Xenophobia In Contemporary Society: A Sociological Analysis ...
African Journals Online (AJOL)
This chapter examines the problem of xenophobia from a sociological perspective. The chapter discusses the problematique of xenophobia as a subject of study and includes an assessment of the incidence/prevalence of xenophobia in contemporary society, as well as indicators of xenophobia. The chapter also provides ...
16. Reflections on Interdisciplinary Collaboration between Sociology ...
African Journals Online (AJOL)
If the original ambition of sociology to constitute itself into an encyclopaedia of the social sciences has largely failed (because of the obligation to restrict its scope through disciplinary specialization), the discipline has been more successful as a key actor in interdisciplinary and trans-disciplinary encounters that cover a wide ...
17. Social kapital og økonomisk sociologi
DEFF Research Database (Denmark)
Svendsen, Gunnar Lind Haase; Svendsen, Gert Tinggaard
2003-01-01
Hvad er social kapital? Vi søger at besvare dette spørgsmål i en tværvidenskabelig tilgang, som forener økonomi og sociologi. Dette sker i tre dele. Det generelle økonomiske udgangspunkt er hentet fra New Institutional Economics (NIE) med dets fokus på asymmetrisk information og deraf følgende...
18. "World Religions" in Introductory Sociology Textbooks
Science.gov (United States)
Carroll, Michael P.
2017-01-01
A section on "world religions" (WRs) is now routinely included in the religion chapters of introductory sociology textbooks. Looking carefully at these WR sections, however, two things seem puzzling. The first is that the criteria for defining a WR varies considerably from textbook to textbook; the second is that these WRs sections…
19. Sociological and medical aspects of Chernobyl accident
International Nuclear Information System (INIS)
Kotlyarov, I.V.; Terebov, A.S.
1993-01-01
The sociological survey data, the results of the state of health service in some districts of Gomel and Mogilev regions as well as of the completeness of the fulfillment of state resolutions concerning the liquidation of the Chernobyl accident after effects are given
20. From Medicalisation to Pharmaceuticalisation - A Sociological Overview. New Scenarios for the Sociology of Health
Directory of Open Access Journals (Sweden)
Bordogna Mara Tognetti
2014-12-01
Full Text Available The aim of this paper is to analyse the sociological literature on pharmaceuticalisation and see how sociology helps us understand and explain the phenomenon. We then discuss how sociology, especially in Anglo-Saxon countries, defines the process of pharmaceuticalisation and how this last is evolving. The paper points out that, while medicalisation remains a key concept for health sociology, it is increasingly being queried and/or extended to allow for a techno-scientific era of biomedicalisation (Clarke et al. 2003 and to acknowledge the importance of the pharmaceutical industry in this process (Williams, Martin and Gabe 2011a, 2011b. Particular attention will be paid to the process of pharmaceuticalisation as brought about not just by doctors and their prescriptions, but by the central role of pharmaceutical promoters and the marketing of drugs.
1. American Sociology in a Transnational World: Against Parochialism.
Science.gov (United States)
Lie, John
1995-01-01
Maintains that, in spite of its cosmopolitan origins, U.S. sociology is regarded widely as parochial in its outlook and concerns. Discusses factors contributing to the intellectual isolationism of U.S. sociological research and pedagogy. Provides suggestions for internationalizing the sociology curriculum. (CFR)
2. Toward a Buddhist Sociology: Theories, Methods, and Possibilities
Science.gov (United States)
Schipper, Janine
2012-01-01
This article explores potential links between Buddhism and sociology, highlighting the many commonalities between sociology and Buddhism, with an emphasis on ways that Buddhist thought and practice may contribute to the field of sociology. What could Buddhism offer to our understanding of social institutions, social problems, and to the dynamics…
3. Durkheim's Sociology of Education: Interpretations of Social Change Through Education
Science.gov (United States)
Goldstein, Marc A.
1976-01-01
Three questions are examined: (1) Why have contemporary American educators generally ignored Durkheim's sociology of education? (2) What were Durkheim's contributions to the sociology of education as his analysis related to social change through education? and (3) What is the relationship between Durkheim's sociology of education, social change,…
4. Polish Qualitative Sociology: The General Features and Development
OpenAIRE
Konecki, Krzysztof Tomasz
2005-01-01
The article explores the development of Polish qualitative sociology in Poland by presenting its main intellectual routes and some of the general features of Polish sociology. Romanticism and inductionmethod are crucial elements for the development of this discipline in Poland and contribute to its. unigueness. The role of Florian Znaniecki in creating the Polish qualitative sociology is also underlined. Krzysztof Konecki
5. Enriching Sociology 100: Using the Novel "Things Fall Apart"
Science.gov (United States)
Hartman, Cheryl J.
2005-01-01
The author has been teaching Introduction to Sociology for several years, and each semester new students bring their own perspectives to the study of sociology, making the content fresh and new. In order to help students understand sociological concepts in more experiential ways and to give them a glimpse into a culture that may be different from…
6. Simulating Secularization: A Pedagogical Strategy for the Sociology of Religion
Science.gov (United States)
May, Matthew
2015-01-01
Instructing students in sociological theory is a foundational part of the discipline, but it can also be a challenge. Readers of "Teaching Sociology" can find a number of activities designed to improve students' understanding of sociological theory in their general theory courses, but there are fewer activities designed to improve…
7. Prevalence of cardiovascular risk factors in an African, Urban inner ...
African Journals Online (AJOL)
The object of this community based study was to determine the prevalence of selected cardiovascular risk factors in an urban inner city community which had been followed up prospectively from 1993 to 1998. Results show that the prevalence of hypertension (Blood Pressure BP > 160/95 mm Hg) was 12.4 percent with an ...
8. Linac 1, inner structure
CERN Multimedia
1968-01-01
This photo shows the inner structure of Linac 1. As injector to the PS, and later to the Booster, Linac 1 accelerated protons to 50 MeV, but it has also accelerated heavier ions. Fitted with a 520 keV RFQ pre-injector (instead of the original Cockcroft-Walton generator), it delivered protons and heavy ions to LEAR, from 1982 to 1992. After 33 years of faithful service, Linac 1 was dismantled in 1992 to make room for Linac 3 (Pb ions).
9. Identifying Sociological Factors for the Success of Space Exploration
Science.gov (United States)
Lundquist, C. A.; Tarter, D.; Coleman, A.
Astrosociology factors relevant to success of future space exploration may best be identified through studies of sociological circumstances of past successful explorations, such as the Apollo-Lunar Missions. These studies benefit from access to primary records of the past programs. The Archives and Special Collections Division of the Salmon Library at the University of Alabama Huntsville (UAH) houses large collections of material from the early periods of the space age. The Huntsville campus of the University of Alabama System had its birth in the mid-1950s at the time when the von Braun rocket team was relocated from Texas to Huntsville. The University, the City of Huntsville and the US Government rocket organizations developed in parallel over subsequent years. As a result, the University has a significant space heritage and focus. This is true not only for the engineering and science disciplines, but also for the social sciences. The life of the University spans the period when Huntsville government and industrial organizations were responsible for producing the rocket vehicles to first take mankind to the Moon. That endeavor was surely as significant sociologically as technologically. In the 1980s, Donald E. Tarter, conducted a series of video interviews with some leading members of the original von Braun team. Although the interviews ranged over many engineering subjects, they also recorded personal features of people involved in the Apollo lunar exploration program and the interactions between these people. Such knowledge was of course an objective. These interviews are now in the collections of the UAH Library Archives, along with extensive documentation from the same period. Under sponsorship of the Archives and the NASA-Marshall Retiree Association, the interview series was restarted in 2006 to obtain comparable oral-history interviews with more than fifty US born members of the rocket team from the 1960s. Again these video interviews are rich with
10. Origins and canons: medicine and the history of sociology.
Science.gov (United States)
Collyer, Fran
2010-01-01
Differing accounts are conventionally given of the origins of medical sociology and its parent discipline sociology. These distinct "histories" are justified on the basis that the sociological founders were uninterested in medicine, mortality and disease. This article challenges these "constructions" of the past, proposing the theorization of health not as a "late development of sociology" but an integral part of its formation. Drawing on a selection of key sociological texts, it is argued that evidence of the founders' sustained interest in the infirmities of the individual, of mortality, and in medicine, have been expunged from the historical record through processes of "canonization" and "medicalization."
11. Towards a global environmental sociology? Legacies, trends and future directions.
Science.gov (United States)
Lidskog, Rolf; Mol, Arthur Pj; Oosterveer, Peter
2015-05-01
A current debate on environmental sociology involves how the subdiscipline should conceptualise and investigate the environment and whether it should be prescriptive and deliver policy recommendations. Taking this debate as a point of departure this article discusses the current and future role of sociology in a globalised world. It discusses how environmental sociology in the US and Europe differ in their understandings of sociology's contribution to the study of the environment. Particular stress is placed on how these two regions differ with respect to their use of the tradition of sociological thought, views on what constitutes the environment and ways of institutionalising environmental sociology as a sociological field. In conclusion, the question is raised of whether current versions of environmental sociology are appropriate for analysing a globalised world environment; or whether environmental sociology's strong roots in European and US cultures make it less relevant when facing an increasingly globalised world. Finally, the article proposes some new rules for a global environmental sociology and describes some of their possible implications for the sociological study of climate change.
12. Field Observations of Surf Zone-Inner Shelf Exchange on a Rip-Channeled Beach
NARCIS (Netherlands)
Brown, J.A.; MacMahan, J.H.; Reniers, A.J.H.M.; Thornton, E.B.
2015-01-01
Cross-shore exchange between the surf zone and the inner shelf is investigated using Lagrangian and Eulerian field measurements of rip current flows on a rip-channeled beach in Sand City, California. Surface drifters released on the inner shelf during weak wind conditions moved seaward due to rip
13. Economics and sociology: Between cooperation and intolerance
Directory of Open Access Journals (Sweden)
Stojanović Božo
2007-01-01
Full Text Available In social sciences two opposing tendencies act simultaneously: the growth of specialization and the need for synthesis. Similar tendencies are noticeable when economics and sociology are in question. The need for these two sciences to cooperate was noticed a long time ago. However, an increasingly intensive exchange has been achieved only recently, particularly in the explanation of individual and group behavior. The works of Mancur Olson are a good example how the results of economics can be inspiring for the research in other sciences, particularly sociology and political science. Applying the results he got by analyzing the logic of collective action, Olson managed to attain significant insight concerning the functioning of economics and society as a whole.
14. Sociological perspectives for the study of nature
Directory of Open Access Journals (Sweden)
2016-05-01
Full Text Available The objective of this work is to explain the society-nature relationship from the disciplines Environmental Sociologyand Cultural Sociology which reveal the arranging function of culture in the orientation of the everyday social doing with respect to the management of novel because it, passes over the thesis that Sociology of Culture states, which is centered in the role of the institucional component a as regulator of the social doing so as to stop the deterioration of the natural spaces. The result consist of the systematization of the theoretical grounds of the disciplines the allow to understand the meaning of culture in social organization around the individuals and groups doing on the nature as objest of analysis.
15. Why Economists Should Pay Heed to Sociology
DEFF Research Database (Denmark)
Hechter, Michael Norman
2015-01-01
Gintis and Helbing suggest that certain elements from classical sociological theory can be usefully incorporated into a general equilibrium model, thereby providing a superior explanation of social behavior. Although the paper seemingly is addressed to sociologists, I argue that their message...... is likely to fall on deaf ears. Instead, their paper should properly be addressed to economists. Whether economists are prepared to listen, however, is an open question....
16. USSR Report, Political and Sociological Affairs.
Science.gov (United States)
1985-09-12
discord or hatred are fermented in connection with religious cults. CSO: 1809/15 72 JPRS-ÜPS-85-071 12 September 1985 SOCIOLOGY TV VIEWERS ON...is forbidden to bring viticulture products acquired from retail enterprises to canteens and cafes, and the sale of beer in cultural-entertainment...fact that it is planned to open two beer bars, two beer restaurants and a beer -hall on Zelenyy Islands, while Selenyy Island, as the author of the
17. Sociological perspectives on self-help groups
DEFF Research Database (Denmark)
2001-01-01
and significance of self-help groups. FINDINGS: New empirical sociological evidence shows that health care professionals - nurses, psychologists, social workers - have become an integrated part and thus essential actors in self-help groups within as well as outside the framework of the formal health care system...... that it is necessary to introduce new aspects and themes for discussion in the health care debate and the work that goes beyond the predominantly individual orientated treatment and care function....
18. Happiness and Memory: Some Sociological Reflections
OpenAIRE
Laura Hyman
2014-01-01
This article seeks to consider, in an exploratory fashion, the relationship between happiness and memory. Both of these areas of investigation are relative newcomers to sociology, and have rarely, if at all, been studied in tandem. The article draws upon data from qualitative interviews with British adults that formed part of an empirical study of people’s experiences and perceptions of happiness. In doing so, it suggests that people identify their memories and reflections on the past as so...
19. Mod en pragmatisk sociologi om fysisk vold
DEFF Research Database (Denmark)
Jønck, Mikkel Kronborg
2017-01-01
. Som et delvist svar på denne forsømmelse introduceres til den franske sociolog Luc Boltanskis »tilnærmede udkast« til en handlingsteori om vold, som er en del af en større handlingssociologi, der præsenteres i bogen Love and Justice as Competences. Der peges dog på et grundlæggende konceptuelt problem...
20. Preconditions for Citizen Journalism: A Sociological Assessment
OpenAIRE
Hayley Watson
2011-01-01
The rise of the citizen journalist and increased attention to this phenomenon requires a sociological assessment that seeks to develop an understanding of how citizen journalism has emerged in contemporary society. This article makes a distinction between two different subcategories of citizen journalism, that is independent and dependent citizen journalism. The purpose of this article is to present four preconditions for citizen journalism to emerge in contemporary society: advanced technolo...
1. Implicit Discourse: Contributions to a Sociological Analysis
Directory of Open Access Journals (Sweden)
Josep Espluga Trenc
2014-01-01
Full Text Available This article discusses the variety of types or dimensions of implicit discourse. Specifically, a typological characterisation is proposed, based on the intentions of the producer of the discourse, including a distinction between four basic dimensions: insinuated discourse, hidden discourse, ?failed? discourse and underlying discourse. Some examples are provided of each dimension, and then it is held that the proposed typology is useful for the sociological analysis of implicit discourse, that is, for its detection and interpretation.
2. Economics and sociology: Between cooperation and intolerance
OpenAIRE
Stojanović Božo
2007-01-01
In social sciences two opposing tendencies act simultaneously: the growth of specialization and the need for synthesis. Similar tendencies are noticeable when economics and sociology are in question. The need for these two sciences to cooperate was noticed a long time ago. However, an increasingly intensive exchange has been achieved only recently, particularly in the explanation of individual and group behavior. The works of Mancur Olson are a good example how the results of economics can be...
3. ECONOMICS AND SOCIOLOGY: BETWEN COOPERATION AND INTOLERANCE
OpenAIRE
Božo Stojanović
2007-01-01
In social sciences two opposing tendencies act simultaneously: the growth of specialisation and the need for synthesis. Similar tendencies are noticable when economics and sociology are in question. The need for these two sciences to cooperate was noticed a long time ago. However, an incresingly intensive exchange has been achieved only recently, particularly in the explanation of individual and group behavior. The works of Mancur Olson are a good example how the results of economics can be i...
4. Physiological Sociology. Endocrine Correlates of Status Behaviors,
Science.gov (United States)
1975-01-01
affiliative bonding. One psychiatric illness which manifests itself in social structural relationships in a profound was is sociopathic behavior. By the...very nature of the sociopathic individual, persons with the disorder display altered social behavior (Robins, 1966). The question as to whether such...Oxford: Oxford University Press, 1971. Goldman, H., Lindner, L., Dinitz, S., and Allen, H. The simple sociopath : Physiologic and sociologic
5. Debate on class issue in contemporary sociology
Directory of Open Access Journals (Sweden)
Antonić Slobodan
2008-01-01
Full Text Available The contemporary debate on class issue within the sociology in English speaking countries focuses on two questions. The first question is whether the crisis of the Marxist class analysis, which arose as a consequence of weakening of class identity and class behavior, is at the same time a sign of crisis of sociological class conception. There are American, British and Australian sociologists whose answer to this question is affirmative. However, others have been claiming that the Marxist class analysis could be replaced by the Weberian concept of stratification. The second question in this debate is on the exploratory importance of class for sociological analysis. Some sociologists have been claiming that its explanatory capacity is exhausted. However, there are others who argue that classes remain one of the most important tools a modern sociologist has. Finally, this paper points to the third way of saving the class analysis. It is about focusing on collective identity and collective action of the members of "developed" professions, as a kind of "small" classes or "proto-classes".
6. Remembering a sociology of Human Rights
Directory of Open Access Journals (Sweden)
Levy, Daniel
2014-12-01
7. Image city
DEFF Research Database (Denmark)
2003-01-01
Image city exhibition explores a condition of mediation, through a focus on image and sound narratives with a point of departure on a number of Asian cities.......Image city exhibition explores a condition of mediation, through a focus on image and sound narratives with a point of departure on a number of Asian cities....
8. Environmental Analysis of the Groningen City Center
OpenAIRE
GÓMEZ BUGEDA, RICARDO SANTIAGO
2017-01-01
This final thesis project is part of the research that is carrying out by the Gemeente Groningen in order to make the city center more sustainable and livable. The municipality of Groningen has recently published a conceptual development plan for improving the inner-city of Groningen, this report is called Bestemming Binnenstad 01/2016 . The main focus of this report is convert the city center to an environmental friendly downtown, reducing pollution, reroute public and private transpo...
9. ABOUT THE FOUNDERS OF LEGAL SOCIOLOGY AND THEIR IDEAS
Directory of Open Access Journals (Sweden)
MIRELA CRISTIANA NILĂ STRATONE
2013-05-01
Full Text Available The main founders of the juridical sociology are considered to be Eugen Ehrlich, Max Weber, Theodor Geiger and Georges Gurvitch, The researches of juridical sociology from Romania are demonstrating the existence of a real tradition in this domain at a national standard. Some roumanian explores of formation jurists have practicated in the cognitive demarche a sociologycal abordation about the law, what have been fatal conduced to the fixing of the base of the juridical sociology in Romania.
10. Polish Qualitative Sociology: The General Features and Development
OpenAIRE
Konecki, Krzysztof Tomasz; Kacperczyk, Anna; Marciniak, Łukasz
2005-01-01
Forum Qualitative Sozialforschung / Forum: Qualitative Social Research,2005, 6(3) The article explores the development of Polish qualitative sociology in Poland by presenting its main intellectual routes and some of the general features of Polish sociology. Romanticism and inductionmethod are crucial elements for the development of this discipline in Poland and contribute to its. unigueness. The role of Florian Znaniecki in creating the Polish qualitative sociology is also underlined.
11. Towards a global environmental sociology? Legacies, trends and future directions
Science.gov (United States)
Lidskog, Rolf; Mol, Arthur PJ; Oosterveer, Peter
2014-01-01
A current debate on environmental sociology involves how the subdiscipline should conceptualise and investigate the environment and whether it should be prescriptive and deliver policy recommendations. Taking this debate as a point of departure this article discusses the current and future role of sociology in a globalised world. It discusses how environmental sociology in the US and Europe differ in their understandings of sociology’s contribution to the study of the environment. Particular stress is placed on how these two regions differ with respect to their use of the tradition of sociological thought, views on what constitutes the environment and ways of institutionalising environmental sociology as a sociological field. In conclusion, the question is raised of whether current versions of environmental sociology are appropriate for analysing a globalised world environment; or whether environmental sociology’s strong roots in European and US cultures make it less relevant when facing an increasingly globalised world. Finally, the article proposes some new rules for a global environmental sociology and describes some of their possible implications for the sociological study of climate change. PMID:25937642
12. The case for a sociology of dying, death, and bereavement.
Science.gov (United States)
Thompson, Neil; Allan, June; Carverhill, Philip A; Cox, Gerry R; Davies, Betty; Doka, Kenneth; Granek, Leeat; Harris, Darcy; Ho, Andy; Klass, Dennis; Small, Neil; Wittkowski, Joachim
2016-01-01
Dying, death, and bereavement do not occur in a social vacuum. How individuals and groups experience these phenomena will be largely influenced by the social context in which they occur. To develop an adequate understanding of dying, death, and bereavement we therefore need to incorporate a sociological perspective into our analysis. This article examines why a sociological perspective is necessary and explores various ways in which sociology can be of practical value in both intellectual and professional contexts. A case study comparing psychological and sociological perspectives is offered by way of illustration.
13. Classical sociology and cosmopolitanism: a critical defence of the social.
Science.gov (United States)
Turner, Bryan S
2006-03-01
It is frequently argued that classical sociology, if not sociology as a whole, cannot provide any significant insight into globalization, primarily because its assumptions about the nation-state, national cultures and national societies are no longer relevant to a global world. Sociology cannot consequently contribute to a normative debate about cosmopolitanism, which invites us to consider loyalties and identities that reach beyond the nation-state. My argument considers four principal topics. First, I defend the classical legacy by arguing that classical sociology involved the study of 'the social' not national societies. This argument is illustration by reference to Emile Durkheim and Talcott Parsons. Secondly, Durkheim specifically developed the notion of a cosmopolitan sociology to challenge the nationalist assumptions of his day. Thirdly, I attempt to develop a critical version of Max Weber's verstehende soziologie to consider the conditions for critical recognition theory in sociology as a necessary precondition of cosmopolitanism. Finally, I consider the limitations of some contemporary versions of global sociology in the example of 'flexible citizenship' to provide an empirical case study of the limitations of globalization processes and 'sociology beyond society'. While many institutions have become global, some cannot make this transition. Hence, we should consider the limitations on as well as the opportunities for cosmopolitan sociology.
14. The Sociological Imagination and Community-Based Learning: Using an Asset-Based Approach
Science.gov (United States)
Garoutte, Lisa
2018-01-01
Fostering a sociological imagination in students is a central goal for most introductory sociology courses and sociology departments generally, yet success is difficult to achieve. This project suggests that using elements of asset-based community development can be used in sociology classrooms to develop a sociological perspective. After…
15. Gangs and a global sociological imagination.
Science.gov (United States)
Fraser, Alistair; Hagedorn, John M
2018-02-01
Across the globe, the phenomenon of youth gangs has become an important and sensitive public issue. In this context, an increasing level of research attention has focused on the development of universalized definitions of gangs in a global context. In this article, we argue that this search for similarity has resulted in a failure to recognize and understand difference. Drawing on an alternative methodology we call a 'global exchange', this article suggests three concepts-homologies of habitus, vectors of difference and transnational reflexivity-that seek to re-engage the sociological imagination in the study of gangs and globalization.
16. Assessing the sociology of sport : On critical sport sociology and sport management
NARCIS (Netherlands)
Knoppers, Annelies
2015-01-01
On the 50th anniversary of the ISSA and IRSS, Annelies Knoppers, one of the leading scholars in understanding the culture of sport in organizational settings, considers how the critical lens of sociology can enhance and mesh with research on sport management. Knoppers argues that there have been
17. Choices and Chances: The Sociology Role-Playing Game--The Sociological Imagination in Practice
Science.gov (United States)
Simpson, Joseph M.; Elias, Vicky L.
2011-01-01
This article introduces a sociology role-playing game (RPG) used to demonstrate the broad range of social forces, institutions, and structures in a semester-long series of in-class and homework assignments. RPGs and other simulation games have been frequently suggested as a useful teaching methodology because of their unique ability to allow…
18. Mental health and poverty in the inner city.
Science.gov (United States)
Anakwenze, Ujunwa; Zuberi, Daniyal
2013-08-01
Rapid urbanization globally threatens to increase the risk to mental health and requires a rethinking of the relationship between urban poverty and mental health. The aim of this article is to reveal the cyclic nature of this relationship: Concentrated urban poverty cultivates mental illness, while the resulting mental illness reinforces poverty. The authors used theories about social disorganization and crime to explore the mechanisms through which the urban environment can contribute to mental health problems. They present some data on crime, substance abuse, and social control to support their claim that mental illness reinforces poverty. The authors argue that, to interrupt this cycle and improve outcomes, social workers and policymakers must work together to implement a comprehensive mental health care system that emphasizes prevention, reaches young people, crosses traditional health care provision boundaries, and involves the entire community to break this cycle and improve the outcomes of those living in urban poverty.
19. Being the Change: An Inner City School Builds Peace
Science.gov (United States)
Curry, Marnie W.
2014-01-01
This article describes an urban high school's response to gun violence, chronicling how the school's mission, full-service community orientation, and commitment to authentic cariño (caring) allowed students to respond to grief and tragedy and develop an ongoing peace building movement that seeks to transform students' lives and the communities…
20. Nutrition education and anaemia outcome in inner city black children
African Journals Online (AJOL)
Seugnet
die “Special Supplementary Food Program for Wo- ... from the third National Health and Nutrition Ex- amination Survey ... of sickle cell-anaemia or Thalassemia trait, (4) .... iron were whole grain breads, green peas, broc- ... garding risk factors for childhood iron deficiency ... processed by an office-based screening instru-.
1. Securing Failed Inner-City Communities: The Military's Role
National Research Council Canada - National Science Library
Khan, Oral
1997-01-01
.... Civil authorities were found to be in breach of the social contract which required that, in return for the loyalty of citizens, they would provide that important social good--security--in accordance...
2. Neighbourhood renewal in Cape Town's inner city: Is it gentrification?
African Journals Online (AJOL)
privaat
The second definition is more inclusive. It incorporates ... The choice of definition for this study is that of Bourne .... the same basic floor plan, although they were built in different eras .... data, contingency tables were constructed and the per-.
3. The changing face of inner-city Havana | IDRC - International ...
International Development Research Centre (IDRC) Digital Library (Canada)
2011-07-14
Jul 14, 2011 ... The collapse of Cuba's Soviet trading partner and the continued U.S. ... Dubbed the "Cayo Hueso Intervention" it quickly became a model in Cuba for ... The work included analysis of interviews and surveys done in Cayo Hueso. ... Taking a fresh look at old problems yields greater benefits for communities.
4. "Higher Expectations" in the Catholic Inner City High School.
Science.gov (United States)
Harkins, William
1987-01-01
Considers the implications of statistics on death and poverty in minority communities for Catholic high schools with large minority populations. Sees hope at the heart of the Catholic high school. Discusses how teachers, school climate, and careful curriculum design can help instill this hope in the students. (DMM)
5. Dance and History in Inner-City Oakland
Science.gov (United States)
Goodwin, Avilee
2010-01-01
In this article, the author shares how she was able to help young choreographers in East Oakland, California, to find their own creative voices, choose new movement styles and discover dance as a way to express something important and meaningful about their lives through their two-year dance history project. East Oakland School of the Arts (EOSA)…
6. 3PL Services in City Logistics
DEFF Research Database (Denmark)
Aastrup, Jesper; Gammelgaard, Britta; Prockl, Günter
2012-01-01
The purpose of this paper is 1) to develop an overview of activities and services that can add value for users and consignees in city logistics schemes based on Urban Consolidation Centre, and 2) to understand and analyze the perceived value for users and consignees from using such services....... The paper will be based on studies of the city logistics literature and existing city logistics schemes, as well as survey and interview findings from studies of potential users (retailers) in Copenhagen inner city and interviews with existing users (retailers) of existing city logistics services...... in the cities of Maastricht, Netherlands, and Hasselt, Belgium. The paper provides an overview and classification of possible third party logistics services in city logistics schemes. Also, findings about value perceived by current users as well as potential users are presented. Literature on city logistics has...
7. AGROFORESTRY KALIWU IN SUMBA: A SOCIOLOGICAL PERSPECTIVE
Directory of Open Access Journals (Sweden)
Budiyanto Dwi Prasetyo
2016-12-01
Full Text Available Agroforestry is one of the popular land management systems in Indonesia. The system helps the farmers to increase agricultural production, social life, and ecological stability. Traditional community in Sumba had been implementing agroforestry for a long time, known as Kaliwu and as a part of the indigenous knowledge. Kaliwu as a system is constructed socially through an intensive interaction between local people and its environment and transmitted from generation to generation. This study aimed to asses sociological aspects in behind Kaliwu practices, which allegedly become key factor the sustainability of this system socially, exist until now. The study was conducted for a year in 2009 in the Waimangura Village, Sumba Island. As social research, data was collected through social survey on 30 respondents, in-depth interview, observation, and literature review. Data was analyzed by using quantitative and qualitative procedures. The results indicated that sociologically, Kaliwu as an authentic knowledge of land management system passed on from generation to generation and constructed along with the socio-historical practices by the local people of Sumba. Social norms (adherence to traditional values, arrangement of labour systems, conflict management and social institution of farmer group became social factors that play significant role to make kaliwu sustainable.
8. Sociological Theory and Social Reality [ENG
Directory of Open Access Journals (Sweden)
JUAN DÍEZ NICOLÁS
2013-01-01
Full Text Available This paper pretends to demonstrate the complementary relations between three relatively recent sociological theories, each one of which explains a different aspect of the same social object: the origin, diffusion and change of social and cultural values, aiming at demonstrating that there is not such a thing as a sociological theory that explains all, but rather diverse theories that offer partial explanations of social reality. To that effect, and on the basis of the necessary relationship between theory and research, three different theories are evaluated separately: Hawley?s and Duncan?s theory of the social ecosystem, Galtung?s centre-periphery theory, and Inglehart?s theory of values? change in modern-industrial societies, offering theoretical and empirical evidence of their complementary relations, based on Spanish and international data. Social ecosystem and centre-periphery theories show a high level of generalization (through space and time and a high level of abstraction, though both can easily operationalize their main concepts through valid and reliable indicators. The theory of values? change, however, though showing a high level of generalization, is limited in time to the historical period after World War II, and also shows a high level of abstraction. Centre-periphery theory and values? change theory use individual and collective units of analysis, but social ecosystem theory only uses collective units, by definition. The three theories lead to the conclusion that ?security? values will gain a growing importance in present societies.
9. Why Sociology Is Silent Concerning Borders
Directory of Open Access Journals (Sweden)
S.E. Nikolov
2015-08-01
Full Text Available Border in sociological sense means a barrier that separates social groups, strata, their values, and the difference between ways of life between particular social groups. Such groups may be separated by many dividing lines, or borders: social/living conditions, opportunities/prospects, legal rights/customs, viewpoints, and so on. Sometimes mobility does not permit other than individual, or small-group, crossing of these borders. It seems really strange why border topic is almost completely absent from the sociology. It is so pertinent to the fate and shaping of various social groups, depending from the location of the border. We think of a boundary whenever we think of an entity demarcated from its surroundings. Events, too, have boundaries – temporal ones: their beginning, climax, final. All our lives are bounded in the continuum between our births and our deaths. A philosopher would imply also that even imaginary, abstract entities, such as concepts or layouts, have boundaries of their own. One may say that condition for all this boundary/border talk is coherent, and whether it reproduces the world around us’ structure, or the organizing activity of our intellect, are matters of deep philosophical controversy. Borders are difficult to disappear totally even within the European Union, providing some obstacles to the freedom of movement to those left still outside the Schengen agreement.
10. Recent Developments in Sociological Risk Theory
Directory of Open Access Journals (Sweden)
Jens O. Zinn
2006-01-01
Full Text Available This article gives a brief overview of the main streams and recent developments of sociological research and theorising on risk. It outlines shifts in cultural theory on risk, from risk society to reflexive modernisation, from governmentality on risk to governmentality on uncertainty and adds the often neglected systems theory approach. Some important insights result from these developments: Risk and uncertainty should be interpreted as systematically linked to each other because there are different ways beyond instrumental rationality how risk can be managed. Furthermore, risk understood as rational calculation is an uncertain business, too. Risks are at the same time both real and socially constructed. Risks and uncertainties have to be managed case by case. When ignorance or uncertainty is too big there are no general rationalities available to make reasonable decisions. Finally, it is argued for more theoretical integration of the outlined approaches. The article finishes with some considerations regarding the contribution of sociology to risk research. URN: urn:nbn:de:0114-fqs0601301
11. Influence of sociological determinants in consumer behavior
Directory of Open Access Journals (Sweden)
Semra Bujari
2017-12-01
Full Text Available Consumer behavior belongs within the scope of delicate issues in theoretical marketing concepts of marketing. The main reason for such treatment of specific issues derives from human individuality in the decision making process for purchasing. From the complexity of human nature, arise challenges in their efforts to look at the internal motives of consumers, their psychological elements and conditions, the internal psychological determinants of behavior, but also the influence of culture, social class, family, lifestyle, as external sociological determinants, regardless of the particular autonomous characteristics of being socially exposed to certain environmental impacts that are undoubtedly of great importance to one’s behavior as a consumer. On the other hand, there is a series of hidden motifs for which their oversight is necessary because they are crucial to the decision-making process. Having this in mind, the researchers focused their objectives on analyzing the determinants of consumer behavior in the decision-making process to be marketed. Various sources of data have been used in the analysis and the theoretical processing of the work. Most of them have a secondary character and include domestic contemporary literature and foreign literature related to this issue. The basic concept of this paper, besides the introductory part and the conclusions, is also composed of interrelated parts. Given the analysis of different sociological determinants such as culture, social classes, reference groups and so on we understand their impact and their importance in bringing decisions in the market for personal consumption.
12. Towards a Sociology of the Mobile Phone
Directory of Open Access Journals (Sweden)
Jim McGuigan
2005-01-01
Full Text Available Use of the mobile phone is an immensely significant social and cultural phenomenon. However, market hype and utopian dreams greatly exaggerate its importance. The fundamental issue for sociology is the process of change. Bound up with contemporary issues of change, the mobile phone is a prime object for sociological attention both at the macro and micro levels of analysis. This article considers the strengths and weaknesses of four methods for studying the sociality of the mobile phone (social demography; political economy; conversation, discourse and text analysis; and ethnography, the different kinds of knowledge they produce, and the interests they represent. Recent ethnographic research on the mobile phone, particularly motivated by issues around the uncertain transition from 2G to the 3G technology, has examined the actual experience of routine use. Interpretative research is now supplementing purely instrumental research, thereby giving a much more nuanced understanding of mobile communications. Critical research on the mobile phone, of which there is little, is beginning to ask skeptical questions that should be pursued further.
13. City of layers
DEFF Research Database (Denmark)
Jensen, Ole B.
2007-01-01
This paper explores the construction of the ‘Sky Train' in central Bangkok. The research question explores the potential socially segregating effect of the Sky Train on Bangkok mobility patterns. The conclusion is that in the networked urban geographies of Bangkok's transportation system new...... mobility practices are played out in a relational space where the potential for movement is shifted in favour of the elite and the tourists. The Sky Train reconfigures the mobility patterns of the inner city of Bangkok in ways that are more than planning policies to overcome congestion and traffic jams...
14. The Emergence and Development of the Sociology of Sport as an Academic Specialty.
Science.gov (United States)
Loy, John W.; And Others
1980-01-01
Sport sociology as an academic specialty and its stages of development are described. Problems confronting future developments in sport sociology include critical mass, academic status, and ideological orientation, both in physical education and in sociology. (CJ)
15. Goffman Meets Bauman at the Shopping Mall - en diakron konfrontation om selv, samfund og sociologi
DEFF Research Database (Denmark)
Jacobsen, Michael Hviid
2008-01-01
This article offers a diachronic confrontation between the sociological perspectives of Erving Goffman and Zygmunt Bauman respectively. Due to their different locations in the history of sociology as well as their diametrically opposed locations regarding substantial discussions within sociolog...
16. History, Science And The Dilemma Of Contemporary Sociology: The ...
African Journals Online (AJOL)
History and natural sciences are two important fields of study that have informed and influenced sociology as a discipline. Traditionally common to these influences on sociology is the need to generalise. Today, however only the natural sciences can still lay claim to this principle. In generalising, the natural science ...
17. Sport and Society: An Introduction to Sociology of Sport.
Science.gov (United States)
Ibrahim, Hilmi
A theoretical framework for the study of sport sociology is provided in this text. It is intended for students of sport, arts and humanities, sociology, and social psychology. Sport and social organization are discussed first. Three models of societies and six theories of social organization are presented which form the basis of the eclectic…
18. Avoiding Chaos in the Sociology of Sport Brickyard.
Science.gov (United States)
McPherson, Barry D.
1978-01-01
If the sociology of sport is to flourish as a legitimate field of inquiry which can contribute valid knowledge rather than an array of bits of knowledge, a sociological perspective based on a sound philosophy of science must be adopted. (Author/LH)
19. Guidelines for Teaching Undergraduate Sport Sociology. Guidance Document
Science.gov (United States)
Coakley, Jay; Riemer, Brenda; Sailes, Gary; Harrison, Louis; Pittman, Beverly
2009-01-01
Sport sociology is a subdiscipline of sociology that, since the late 1960s, has produced knowledge about sports as social phenomena in a wide range of societies. It may be included as a major specialization area in graduate programs in kinesiology, sports studies and physical education departments, and is widely offered as a single undergraduate…
20. The Development of Visual Sociology: A view from the inside
Directory of Open Access Journals (Sweden)
Douglas Harper
2016-12-01
Full Text Available This paper is a reflection by one of the founding members of the IVSA (International Visual Sociology Association about the events, ideas, social trends and revolutions within sociology that contributed to development of visual sociology. In 2016 the IVSA entered its 34th year and the author has been a participant in the organization for its full duration. The paper details the importance of documentary photography in the early era of visual sociology. During this era key papers by Howard Becker contributed to the intellectual movement’s original intellectual definition and created a pedagogical model that has served as a model for teaching visual sociology to this day. Moving from visual sociology as a method based on black and white photography, the discipline embraced and developed collaborative methods including photo elicitation and photovoice. A parallel track of visual sociology focused on the analysis of the visual dimension of society, drawing on semiotics and cultural studies. More recently visual sociology has begun to explore the rapidly changing meaning and social function of photographic imagery, as cameras and images have become ubiquitous in the cell phone era.
1. Teaching Writing in Sociology: A Social Constructionist Approach.
Science.gov (United States)
Anderson, Leon; Holt, Mara
1990-01-01
Provides an overview of the "social constructionist" approach to teaching composition in sociology courses. Describes a course that is team taught by the authors and is based on the social constructionist paradigm. Stresses that sociological writing is a special type of discourse that can be taught most effectively by sociologists who…
2. Rural Sociology in Brazil: Institutional Growth (1965-1977).
Science.gov (United States)
Hansen, David O.; And Others
Growth and present status of graduate programs, major research interests, and potential for US-Brazilian collaboration indicate the present state of rural sociology in Brazil. In contrast to US rural sociology's identity crisis of the past decade, the field in Brazil has blossomed. Graduate programs are underway at universities of Rio Grande do…
3. The Structure of Sociology in the Educational Activities of Unesco
Science.gov (United States)
Card, B. Y.
1974-01-01
An exploration of the structure of sociology in Unesco's educational activities during 1970-1971 reveals that Unesco has dual political and cultural bureaucratic structures that are complementary for contributions in sociology. Journal is available from Mouton & Co., 5 Herder Street, The Hague, Netherlands. (ND)
4. Pour une Sociologie des Apprentissages (Toward a Sociology of Learning)
Science.gov (United States)
Porcher, Louis
1977-01-01
A language, a social practice, cannot be taught or learned apart from determining sociological factors. The effect of this sociological understanding on foreign language methodology, particularly the functional approach, and learner-centered education is discussed. (Text is in French.) (AMH)
5. Labor Economics and Sociology of Labor: Demarkation Problem
Directory of Open Access Journals (Sweden)
S N Lebedev
2011-06-01
Full Text Available The article deals with important economic and sociological problems taking into account their relevance to economics and sociology of labor as two independent sciences. The author suggests some demarcation boundaries of the concepts relevant to contemporary life within these two disciplines.
6. Towards a Realist Sociology of Education: A Polyphonic Review Essay
Science.gov (United States)
Grenfell, Michael; Hood, Susan; Barrett, Brian D.; Schubert, Dan
2017-01-01
This review essay evaluates Karl Maton's "Knowledge and Knowers: Towards a Realist Sociology of Education" as a recent examination of the sociological causes and effects of education in the tradition of the French social theorist Pierre Bourdieu and the British educational sociologist Basil Bernstein. Maton's book synthesizes the…
Science.gov (United States)
Nell Trautner, Mary; Borland, Elizabeth
2013-01-01
The sociological imagination is a useful tool for teaching about plagiarism and academic integrity, and, in turn, academic integrity is a good case to help students learn about the sociological imagination. ?We present an exercise in which the class discusses reasons for and consequences of dishonest academic behavior and then examines a series of…
8. Representing the Other in Sociology of the Family Texts
Science.gov (United States)
Dunham, Charlotte Chorn; Cannon, Julie Harms; Dietz, Bernadette
2004-01-01
The purpose of this paper is to explore the concept of otherness as it applies to the content of sociology of the family texts. We conducted a study of the content of the indexes and the body of texts on sociology of the family, examining the way in which the experiences of whites were addressed relative to families of color. We found that whites…
9. Polish Qualitative Sociology. Insight into the future of postdisciplinary research
OpenAIRE
Konecki, Krzysztof
2014-01-01
The paper desctibes the definitions of following concepts: multidisiplinarity, interdisciplinarity, transdysciplinarity, postdisciplinarity. MOreover it discuss the meanings of a concept of discipline. It describes the place of the Polish qualitative sociology in the context of postdisciplinary research. The main question of paper is: Does the POlish Qualitative Sociology has entered the postdisciplinary phase of research? DGS, UL Krzysztof Konecki
10. The Empty Shops Project: Developing Rural Students' Sociological Insight
Science.gov (United States)
Willis, Evan; Burns, Edgar
2011-01-01
An informal research project with high local relevance was developed for a first-year sociology course at an Australian rural university campus. The project developed students' sociological insight by challenging them to investigate "truths" about their own region, rather than immediately pushing them to comprehend new and different…
11. Negation and Affirmation: a critique of sociology in South Africa ...
African Journals Online (AJOL)
This paper critically evaluates the epistemological basis of the academic discipline of sociology in South Africa. In particular, it contextualises, and therefore subjects to critical scrutiny, the assumptions made (and not made) by South African sociologists in their writings about the discipline of sociology in South Africa.
12. The Challenges of Teaching and Learning Sociology of Religion in ...
African Journals Online (AJOL)
The teaching and learning of Sociology of Religion in Nigeria face some grave challenges. As an academic discipline in religious studies, many who teach this specialized discipline are not experts. This makes Sociology of. Religion anybody's game which does not promote sound scholarship, creativity and intellectual ...
13. Revisiting the Utility of Industrial Sociology in National Development ...
African Journals Online (AJOL)
Sociology as an academic discipline has been entrenched in many Nigerian universities, however, not much is known about how the discipline has contributed or has been contributing to the national development. Although some scholars have discussed some contributions of sociology in the emerging economy like ...
14. The Educational Imagination and the Sociology of Education in Australia
Science.gov (United States)
Matthews, Julie
2013-01-01
A remarkable feature of the sociology of education is its proliferation under a broad gamut of research themes and topics. Understanding the relationship of education to social reproduction and social change are pivotal to the sociology of education, and have fruitfully informed research in fields such as gender and education, vocational education…
15. The "Biographical Turn" in University Sociology Teaching: A Bernsteinian Analysis
Science.gov (United States)
McLean, Monica; Abbas, Andrea
2009-01-01
Little is known about what happens to disciplinary knowledge when it is taught in contemporary UK universities of different status. Here, Basil Bernstein's theories are applied to what sociology lecturers say about teaching, demonstrating that in conditions in which students are less likely to engage with sociological theory, lecturers,…
16. Reframing sociologies of ethnicity and migration in encounters with Chinese London.
Science.gov (United States)
Knowles, Caroline
2017-09-01
In this paper I argue that the intersecting sociologies of ethnicity and migration work from a series of interconnected blind spots hindering effective analysis of the current UK situation. Both operate analytically within the limitations of an 'immigrant problem' framework; are overinvested in state agendas; privilege a nation state analysis; are narrowly focused on distributions of migrant bodies, and on receiving, at the expense of sending, contexts. Exploring these limitations with data derived from a modest small-scale qualitative study of young Chinese migrants in London, I argue for a reframing along four dimensions. Firstly, in an era of elite migration, sociology could reach beyond its immigrant problem framework and open up to a broader range of UK migrant ethnicities and circumstances. Secondly, a stronger focus on cities as the scale on which lives are lived, and through which diverse streams of translocal activity are routed, would open new avenues of sociological exploration. Thirdly, including translocal activities connected with distributions of ethnic migrant bodies, such as capital transfers, would broaden its focus, taking migration and ethnicity more centrally into the analysis of globalization as one of its constituting practices. Finally, paying attention to sending, as well as arrival cities, reveals migrants' thinking and shapes the ways in which they live, as my data shows. The Chinese are both one of the UK's neglected minorities, and one of its fastest growing populations. They are a good example of new UK migrants and they bring globalization's realignment with the rising significance of China to the UK. © London School of Economics and Political Science 2017.
17. City evacuations an interdisciplinary approach
CERN Document Server
Binner, Jane; Branicki, Layla; Galla, Tobias; Jones, Nick; King, James; Kolokitha, Magdalini; Smyrnakis, Michalis
2015-01-01
Evacuating a city is a complex problem that involves issues of governance, preparedness education, warning, information sharing, population dynamics, resilience and recovery. As natural and anthropogenic threats to cities grow, it is an increasingly pressing problem for policy makers and practitioners. The book is the result of a unique interdisciplinary collaboration between researchers in the physical and social sciences to consider how an interdisciplinary approach can help plan for large scale evacuations. It draws on perspectives from physics, mathematics, organisation theory, economics, sociology and education. Importantly it goes beyond disciplinary boundaries and considers how interdisciplinary methods are necessary to approach a complex problem involving human actors and increasingly complex communications and transportation infrastructures. Using real world case studies and modelling the book considers new approaches to evacuation dynamics. It addresses questions of complexity, not only ...
18. City PLANTastic
DEFF Research Database (Denmark)
, any attempt to create a green city is motivated by certain ecological, political and esthetical perspectives. Therefore the role of plants in tomorrows cities is everything but straightforward. Rather, a broad range of possibilities unfolds. City PLANTastic is the title of the 8th World in Denmark...
19. INSTANT CITY
DEFF Research Database (Denmark)
Marling, Gitte; Kiib, Hans
2013-01-01
of an experimental and social en- gaged city environment? The analysis shows that the specific city life at the instant city, Roskilde Festival, can be characterized by being ‘open minded’, ‘playful’ and ‘inclusive’, but also by ‘a culture of laughter’ that penetrates the aesthetics and the urban scenography....
20. Zamyšlení nad soudobou českou sociologií
OpenAIRE
Musil, Jiri
2002-01-01
The following comments compare the present orientations of Czech sociology with recent developments in European sociology. The analysis of sociology in Europe shows that the attention of European sociologists has shifted to social theory & social philosophy, sociology of culture, media, gender & feminism, political sociology, nationalism, ethnicity, & racism. Czech sociology, in the opinion of the author, still does not pay sufficient attention to such pressing issues of Czech society as nati...
1. The origin of the inner voice
DEFF Research Database (Denmark)
Bjerre, Jørn
2013-01-01
While the influence of classical philosophy on sociology has been the subject of several studies, less attention has been given to the question of how the founders of sociology viewed classical philosophy. This article discusses Émile Durkheim’s account of the historical role of Greek philosophy ...
2. Sociologia e literatura Sociology and literature
Directory of Open Access Journals (Sweden)
Maria Célia Leonel
2009-10-01
Full Text Available Propomos discutir como Os sertões foi incorporado, pela crítica, como obra de literatura e como, posteriormente, o romance Grande sertão: veredas passou a ser lido como ensaio. Para tanto, examina-se, de um lado, em vários estudos, como o primeiro foi consagrado como obra compósita, pertencendo, ao mesmo tempo, ao campo da literatura, da sociologia e da ciência, o que se tornou moeda corrente e cânone quase inquestionável, sobrevivendo por mais de um século. De outro lado, investiga-se como a narrativa rosiana passou a ser vista, por uma determinada vertente da crítica, como ensaio ou estudo das relações de poder no Brasil. É essa indistinção, paradoxal, entre sociologia e literatura, ciência e fi cção que nos propomos investigar e problematizar, buscando compreender tal embaralhamento de gêneros. Palavras-chave: Grande sertão: veredas. Os sertões. Ficção. Sociologia. Ensaio. Crítica. The purpose is to discuss how Os sertões has been incorporated, by the critics, as literary work and how, after that, the novel Grande sertão: veredas started to be read as an essay. In order to achieve that, there is the examination, from one side, of several studies, on how the fi rst has been consecrated as composite work belonging, at the same time, to the literature, sociology and science fi elds, what has come as currency and unquestionable standard, surviving for over a century. On the other hand, there is the investigation of how the narrative of Rosa started to be seen, by a determined share of the critics, as essay or study of the power relationships in Brazil. It is this non-distinction, this paradox, between sociology and literature, science and fi ction, that we propose to investigate and put into matter, searching for comprehension in this gender mixture. Keywords: Grande sertão: veredas. Os sertões. Fiction. Sociology. Essay. Critics.
3. Renewing Sociology of Education? Knowledge Spaces, Situated Enactments, and Sociological Practice in a World on the Move
Science.gov (United States)
Seddon, Terri
2014-01-01
Sociology of education is caught in a dilemma. The study of education and society that unfolded through the twentieth century produced educational vocabularies that spoke into education policy and practice about inequality and social justice. Now that sociologically informed educational discourse is marginalised by individualistic…
4. All about science philosophy, history, sociology & communication
CERN Document Server
Lam, Liu
2014-01-01
There is a lot of confusion and misconception concerning science. The nature and contents of science is an unsettled problem. For example, Thales of 2,600 years ago is recognized as the father of science but the word science was introduced only in the 14th century; the definition of science is often avoided in books about philosophy of science. This book aims to clear up all these confusions and present new developments in the philosophy, history, sociology and communication of science. It also aims to showcase the achievement of China's top scholars in these areas. The 18 chapters, divided into five parts, are written by prominent scholars including the Nobel laureate Robin Warren, sociologist Harry Collins, and physicist-turned-historian Dietrich Stauffer.
5. 'Material' in Adorno's sociology of music
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Jeremić-Molnar Dragana
2008-01-01
Full Text Available In the article the authors are dealing with the musical 'material' as the key concept of Theodor Adorno's sociology of music. Being a synthesis of two, ideologically opposite - Schonberg's and Marx's - legacies, Adorno's 'material' combines also quite opposite meanings. On the one side, it echoes Schonberg's theory of relationship between tone (as natural phenomena and unconscious 'instinct' (that transforms composer into some kind of the tool of nature, and whole mankind as well. On the other side, Adorno was following Karl Marx general theory of capitalism (all cultural phenomena are determined by the material production, with one crucial innovation. Adorno's 'material' was reflecting the lack of virtual communist revolution, instead of its preparation (in the bosom of totalitarian capitalism. As the result of Adorno's 'negative dialectics' in the field of music, it was carrying the message of the suppressed apocalypse. .
6. Sociologies of energy. Towards a research agenda
Directory of Open Access Journals (Sweden)
Tomás Ariztía
2017-12-01
Full Text Available This article offers a panoramic view of the field of the social studies of energy while introducing the articles of the special issue. It begins by discussing the progressive interest on studying the social aspects of energy. We relate this interest to the increasing challenges imposed by global climate change as well as the growing sociological attention to the material dimension of social life. The article suggests understanding energy and energy related phenomena as a socio-technical object which involve material, social, cultural and technical elements. The article then briefly describes different research areas concerning the intersection between energy and society and present the contributions to the monograph. We suggest that the articles comprised in this special issue are not only relevant for social scientist interested on energy related issues; they might also help energy professionals and researchers from outside the social sciences to further problematize the social aspects and challenges of energy.
7. Sociological aspects of meat in meals
DEFF Research Database (Denmark)
Jensen, Katherine O'Doherty
2009-01-01
Health professionals and environmental experts advocate reduced consumption of meat in industrialized regions. On this background, and in light of a number of sociological studies of food practices and meal formats among consumers, this paper examines some aspects of the cultural entrenchment...... and vulnerability of meat consumption. Tacit meanings of meat products are seen as arising from the human tendency to rank and grade objects relative to each other, a process that is intrinsic to consumption practices. Examples of the ways in which gradient meanings of meat products are entrenched in food practices...... and of ways in which this consumption is vulnerable to change, are presented. On this basis, the likelihood that current levels of meat consumption in industrialized societies will remain relatively stable or tend to decrease are briefly discussed....
8. THE SOCIOLOGIC APPROACH OF FEMININE CRIMINALITY
Directory of Open Access Journals (Sweden)
MIRELA CRISTIANA NILA STRATONE
2012-05-01
Full Text Available The present study is part of a much more cognitive approach, which tries to study resocialization and the social reinsertion of women who are under freedom privation penalty. The present material contains a short historical evolution of the sociologic theories of crime, then plunging towards feminist theories, in order to approach the gender problematic concerning the delinquent woman.. The first objective is to demonstrate the necessity of a wider approach in analyzing the genesis of the crime, through the re-evaluation and reconsidering the factors with a crime risk and placing them in an equal position in the social environment. Another objective of this study is to emphasize the importance of the gender role concerning the expectations of the society from the feminine population’s side. The present study is focused on the contribution of placing the research of feminine crime research on a basis characterized by unprecedented generality, under total influencing conditions, with orientation towards gender problematic.
9. Tales of sociology and the nursing curriculum: revisiting the debates.
Science.gov (United States)
Aranda, Kay; Law, Kate
2007-08-01
The relationship between nursing and sociology has been extensively debated for more than two decades [Cox, C.A., 1979. Who cares? Nursing and sociology: the development of a symbiotic relationship. Journal of Advanced Nursing 4, 237-252; Cooke, H., 1993. Why teach sociology? Nurse Education Today 13, (3) 210-216; Sharpe, K., 1994. Sociology and the nursing curriculum: a note of caution. Journal of Advanced Nursing 20, (2) 391-395; Sharpe, K., 1995. Why indeed should we teach sociology? A response to Hannah Cooke. Nurse Education Today 15, (1) 52-55; Sharpe, K., 1996. Feedback - sociology and the nursing curriculum: a reply to Sam Porter. Journal of Advanced Nursing 23, (7) 1275-1278; Balsamo, D., Martin, S.I., 1995a. Developing the sociology of health in nurse education: towards a more critical curriculum. Part 1. Andragogy and sociology in Project 2000. Nurse Education Today 15, 427-432; Balsamo, D., Martin, S.I., 1995b. Developing the sociology of health in nurse education: towards a more critical curriculum. Part 2. Linking methodology and epistemology. Nurse Education Today 15, 427-432; Porter, S., 1995. Sociology and the nursing curriculum: a defence. Journal of Advanced Nursing 21, (6) 1130-1135; Porter, S., 1996. Why teach sociology? A contribution to the debate. Nurse Education Today, 16, 170-174; Porter, S., 1997. Sociology and the nursing curriculum: a further comment. Journal of Advanced Nursing 26, (1) 214-218; Porter, S., 1998. Social Theory and Nursing Practice. Macmillan, Basingstoke; Corlett, J., 2000. The perceptions of nurse teacher, student nurses and preceptors of the theory-practice gap in nurse education. Nurse Education Today 20, 499-505; Allen, D., 2001. Review article: nursing and sociology: an uneasy marriage?. Sociology of Health and Illness 23, (3) 386-396; Pinikahana, J., 2003. Role of sociology within the nursing enterprise: some reflections on the unfinished debate. Nursing and health Sciences 5, (2) 175-180; Holland, K., 2004
10. Regionalization and multiculturalism in sociological perspective
Directory of Open Access Journals (Sweden)
Tripković Milan B.
2002-01-01
Full Text Available This paper is an attempt to deal with current and also controversial problems of regionalization and multiculturality together, by putting them in a broader sociological perspective, and then questioning them on the example of the current position of Vojvodina and growing demands for democratization, deregulation and decentralization of Serbia. Starting with a question how to harmonize very strong need of modern societies for homogenization with the equally strong and legitimate need for heterogeneity, which was one of the first and basic questions that sociology posed to itself, the author points out that regionalization and multiculturality solve nothing by themselves alone, if they are not put in the context of the crisis of modernity, which opens space for constructing essentially different pluralistic society. Process of regionalization in general, and in Serbia particularly, appears as a rational choice only if it goes together with already mentioned processes of democratization deregulation and decentralization, which should provide relatively fast transformation of old structures through development of the new ones. In other words, regionalization must be looked upon as one of the moments of the process of foundation of new pluralistic society, which contributes to opening and development, and not to closing, stagnation or regress, which eliminates or alleviates old conflicts and prevents creation of the new ones, which eliminates harmful consequences of stiff centralization and at the same time does not call for equally harmful unreasonable fragmentation which encourages demands for autonomy of parts and at the same time does not prevent integration and solidarity, which respects differences and does not endanger the social unity.
11. History and Sociology: A genealogical perspective
Directory of Open Access Journals (Sweden)
Ştefan UNGUREAN
2012-01-01
Full Text Available What could we possibly learn from a 70 year correspondence from the years of the Second World War, when the course of subsequent history has already been known? The sociologist is interested in seeing how an event unfolds, how it generates other actions, how the actors are driven by, what their strategies are and how they interact. The aim of the present essay is to identify those sociological concepts, that could lead us to explanations of the geopolitical, regarding the way Germany built up its hegemony, by starting from a genealogical perspective, that is, by identifying the logics of a situation and by understanding the reasoning behind individual decision while taking into consideration the analysis of the discourse. We take into account how enforcing a drastic peace treaty on Germany has lead to high surveillance costs that could not be sustained by the victors because of their path dependence, which ultimately led to the fact of the ‘good’ being sacrificed for the sake of the ‘comfortable’. We understand how military successes represent the test of truth for an ideology and provide the Nazi leaders with their legitimacy, inciting a group phantasm. We discern, in the relations between Germany, Soviet Union and the French-English duo, all the elements of a triad and, implicitly, all elements of power that are generated by a game based on imposing and accepting uncertainties. All of the above bare evidence to the fact that sociological notions and concepts can produce revelations when taken into new domains, such as geopolitics and war.
12. “IDENTITY” IN CONTEMPORARY SOCIOLOGICAL THEORY
Directory of Open Access Journals (Sweden)
N. L. Polyakova
2016-01-01
Full Text Available The problem of identity has come to the fore of contemporary societies in the conditions when the institutional structures of these societies their ascriptive statuses have become looser when modernity is “liquid”, “soft”. Varions conceptualizations of identity are becoming a basic part of contemporary sociological theory. The paper aims to reveal the key problems that sociology faces when striving to work out a theory of identity. The paper takes as its starting point the classic notion of identity. This notion was shaped by Erik Erikson on the basis of his dynamic psychology. The paper proves that the contemporary identity is connected with the process of individualization in modern societies. Numerous and varied studies of contemporary identity can be divided into three large groups according to three methodological approaches: constructivist, postmodern and interactionist. The paper compares the major theories based on these approaches and reveals their theoretical and methodological problems. The paper shows that the constructivist approach is based on the notion of reflexivity which is viewed as a mechanism of identity formation by an individual. Identity is a reflexive project which is being realized in a conscious manner. The postmodern theories of identity reveal the fragmentation incompleteness of ego-identitity and it’s narcissic decay. They also reveal the inability of the individual to solve the problem of continuity and unity of her (his own personality. Identity as a notion is replaced by the notion of identification which reduces identity to varions modes of repsentation. The interactionist methodology conld open up the way to tackle, the problem of individual’s unity and continuity as the main problem of human existence. This is the condition of the individual’s psychic and social health.
13. The sociology of popular music, interdisciplinarity and aesthetic autonomy.
Science.gov (United States)
Marshall, Lee
2011-03-01
This paper considers the impact of interdisciplinarity upon sociological research, focusing on one particular case: the academic study of popular music. 'Popular music studies' is an area of research characterized by interdisciplinarity and, in keeping with broader intellectual trends, this approach is assumed to offer significant advantages. As such, popular music studies is broadly typical of contemporary intellectual and governmental attitudes regarding the best way to research specific topics. Such interdisciplinarity, however, has potential costs and this paper highlights one of the most significant: an over-emphasis upon shared substantive interests and subsequent undervaluation of shared epistemological understandings. The end result is a form of 'ghettoization' within sociology itself, with residents of any particular ghetto displaying little awareness of developments in neighbouring ghettos. Reporting from one such ghetto, this paper considers some of the ways in which the sociology of popular music has been limited by its positioning within an interdisciplinary environment and suggests two strategies for developing a more fully-realized sociology of popular music. First, based on the assumption that a sociological understanding of popular music shares much in common with a sociological understanding of everything else, this paper calls for increased intradisciplinary research between sociologists of varying specialisms. The second strategy, however, involves a reconceptualization of the disciplinary limits of sociology, as it argues that a sociology of popular music needs to accept musical specificity as part of its remit. Such acceptance has thus far been limited not only by an interdisciplinary context but also by the long-standing sociological scepticism toward the analysis of aesthetic objects. As such, this paper offers an intervention into wider debates concerning the remit of sociological enquiry, and whether it is ever appropriate for sociological
14. The sociological imagination in a time of climate change
Science.gov (United States)
Norgaard, Kari Marie
2018-04-01
Despite rising calls for social science knowledge in the face of climate change, too few sociologists have been engaged in the conversations about how we have arrived at such perilous climatic circumstances, or how society can change course. With its attention to the interactive dimensions of social order between individuals, social norms, cultural systems and political economy, the discipline of sociology is uniquely positioned to be an important leader in this conversation. In this paper I suggest that in order to understand and respond to climate change we need two kinds of imagination: 1) to see the relationships between human actions and their impacts on earth's biophysical system (ecological imagination) and 2) to see the relationships within society that make up this environmentally damaging social structure (sociological imagination). The scientific community has made good progress in developing our ecological imagination but still need to develop a sociological imagination. The application of a sociological imagination allows for a powerfully reframing of four key problems in the current interdisciplinary conversation on climate change: why climate change is happening, how we are being impacted, why we have failed to successfully respond so far, and how we might be able to effectively do so. I visit each of these four questions describing the current understanding and show the importance of the sociological imagination and other insights from the field of sociology. I close with reflections on current limitations in sociology's potential to engage climate change and the Anthropocene.
15. Back to Hegel? On Gillian Rose's critique of sociological reason.
Science.gov (United States)
Fuller, Brian W
2017-08-22
Thirty-five years ago, Gillian Rose articulated a significant critique of classical sociological reason, emphasizing its relationship to its philosophical forebears. In a series of works, but most significantly in her Hegel contra Sociology, Rose worked to specify the implications of sociology's failure, both in its critical Marxist and its 'scientific' forms, to move beyond Kant and to fully come to terms with the thought of Hegel. In this article, I unpack and explain the substance of her criticisms, developing the necessary Hegelian philosophical background on which she founded them. I argue that Rose's attempted recuperation of 'speculative reason' for social theory remains little understood, despite its continued relevance to contemporary debates concerning the nature and scope of sociological reason. As an illustration, I employ Rose to critique Chernilo's recent call for a more philosophically sophisticated sociology. From the vantage point of Rose, this particular account of a 'philosophical sociology' remains abstract and rooted in the neo-Kantian contradictions that continue to characterize sociology. © London School of Economics and Political Science 2017.
16. Atomic inner-shell physics
International Nuclear Information System (INIS)
Crasemann, B.
1985-01-01
This book discusses: relativistic and quantum electrodynamic effects on atomic inner shells; relativistic calculation of atomic transition probabilities; many-body effects in energetic atomic transitions; Auger Electron spectrometry of core levels of atoms; experimental evaluation of inner-vacancy level energies for comparison with theory; mechanisms for energy shifts of atomic K-X rays; atomic physics research with synchrotron radiation; investigations of inner-shell states by the electron energy-loss technique at high resolution; coherence effects in electron emission by atoms; inelastic X-ray scattering including resonance phenomena; Rayleigh scattering: elastic photon scattering by bound electrons; electron-atom bremsstrahlung; X-ray and bremsstrahlung production in nuclear reactions; positron production in heavy-ion collisions, and X-ray processes in heavy-ion collisions
17. The LHCb Silicon Inner Tracker
International Nuclear Information System (INIS)
Sievers, P.
2002-01-01
A silicon strip detector has been adopted as baseline technology for the LHCb Inner Tracker system. It consists of nine planar stations covering a cross-shaped area around the LHCb beam pipe. Depending on the final layout of the stations the sensitive surface of the Inner Tracker will be of the order of 14 m 2 . Ladders have to be 22 cm long and the pitch of the sensors should be as large as possible in order to reduce costs of the readout electronics. Major design criteria are material budget, short shaping time and a moderate spatial resolution of about 80 μm. After an introduction on the requirements of the LHCb Inner Tracker we present a description and characterization of silicon prototype sensors. First, laboratory and test beam results are discussed
18. Colour attitude test: the possibility of application in sociology
Directory of Open Access Journals (Sweden)
V P Tkach
2009-09-01
Full Text Available The article provides the analysis of the cognitive potential of colour tests in sociology. Nowadays colour tests which are extensively used in the framework of psychology find practically no application in sociological research due to a number of their peculiarities. However, it should be recognized that such tests as colour attitude test demonstrate the richest cognitive potential for the identification of value preferences and social attitudes system at the level of the unconscious of various social groups. The methodological experiment carried out by the author has proved demonstratively the feasibility and high efficiency of colour attitude tests application in the framework of empirical sociological research.
19. Fifty years of sociological leadership at Social Science and Medicine.
Science.gov (United States)
Timmermans, Stefan; Tietbohl, Caroline
2018-01-01
In this review article, we examine some of the conceptual contributions of sociology of health and illness over the past fifty years. Specifically, we focus on research dealing with medicalization, the management of stigma, research on adherence and compliance, and patient-doctor interaction. We show how these themes that originated within sociology, diffused in other disciplines. Sociology in Social Science and Medicine started as an applied research tradition but morphed into a robust, stand-alone social science tradition. Copyright © 2017 Elsevier Ltd. All rights reserved.
20. Core barrel inner tube lifter
Energy Technology Data Exchange (ETDEWEB)
Jeffers, J P
1968-07-16
A core drill with means for selectively lifting a core barrel inner tube consists of a lifting means connected to the core barrel inner tube assembly. It has a closable passage to permit drilling fluid normally to pass through it. The lifting means has a normally downward facing surface and a means to direct drilling fluid pressure against that surface so that on closure of the passage to fluid flow, the pressure of the drilling fluid is caused to act selectively on it. This causes the lifting means to rise and lift the core barrel. (7 claims)
1. An Environmental Sociology for the Anthropocene.
Science.gov (United States)
Bowden, Gary
2017-02-01
Attention to the relationship between nature and society has been a defining feature of environmental sociology since its inception. Early research, incorporating insights from ecology, argued for the need to (1) theorize the causal connections between nature and society and (2) contextualize those connections in terms of biophysical limits resulting from resource scarcity. Over the past two decades, partly in response to new forms of existential threat such as climate change, the treatment of nature and society as distinct entities has given way to a focus on socio-natural assemblages. Using the Anthropocene as a lens to explore this emerging view, it is argued (1) that current theorizing on the socio-natural assemblage needs to pay more attention to the issues of temporality and complexity, (2) that taking these factors into account reconceptualizes the nature-society relationship as a complex, evolving socio-natural assemblage, (3) that this evolutionary process needs to be understood in the context of cosmic evolution and the tension between entropy and the emergence of local complexity, and (4) that constraints on human development arise from the tension between these two tendencies, not from resource scarcity. An environmental sociology for the Anthropocene, one based on assumptions about the nature of causal dynamics and context consistent with our understanding of current earth system science, is proposed. L'attention portée à la relation entre la nature et la société a été un trait caractéristique de la sociologie de l'environnement depuis sa création. La recherche initiale, intégrant les connaissances de l'écologie, a soutenu la nécessité de (1) théoriser les liens causaux entre la nature et la société et (2) contextualiser ces connexions en termes de limites biophysiques résultant de la pénurie de ressources. Au cours des deux derniéres décennies, en partie en réponse à de nouvelles formes de menace existentielle telles que le
2. The return of the city-state: urban governance and the New York City H1N1 pandemic.
Science.gov (United States)
Hoffman, Lily M
2013-02-01
This article examines New York City's response to the 2009 H1N1 pandemic in the context of the post-9/11 US security regime. While the federal level 'all-hazards' approach made for greater depth of support, it also generated unrealistic assumptions at odds with an effective local response. The combination of structurally induced opportunity and actor specific strengths (size, expertise) made for effective local governance by the New York City Department of Health and Mental Hygiene. By underlining the importance of locality as a first line of defence and linking defence function to policy initiative in regard to health governance, this study illustrates the continuing relevance of Weber's insight into the institutional structure of the city. © 2012 The Author. Sociology of Health & Illness © 2012 Foundation for the Sociology of Health & Illness/Blackwell Publishing Ltd.
3. Teaching Sociology of Education in Canada: A Comparative Study of the "Two Solitudes"
Science.gov (United States)
Jean-Pierre, Johanne
2013-01-01
This study aims to contribute to the fields of sociology of education and Canadian sociological teaching. English and French Canadian sociology of education course outlines were systematically analysed in order to assess how national context, language and internal divisions influence the undergraduate teaching of sociology of education. The…
4. Global Interconnectedness and Multiculturalism in Undergraduate Sociology Courses in the USA
Science.gov (United States)
Shin, Kyoung-Ho
2014-01-01
This study attempts to explain a process of inserting global transnational elements into an undergraduate sociology course. After a review of global themes covered in introductory sociology textbooks, the author administered two projects (Global Multiculturalism and Sociology of Wal-Mart) in an undergraduate sociology course. The current study…
5. The inner dimension of sustainability
NARCIS (Netherlands)
Horlings, L.G.
2015-01-01
Transformation to sustainability has been defined as the fundamental alteration of the nature of a system, once the current conditions become untenable or undesirable. Transformation requires a shift in people's values, referred to as the inner dimension of sustainability, or change from the
6. The Challenges of Teaching and Learning Sociology of Religion in ...
African Journals Online (AJOL)
User
proper learning, training and research in Sociological theories, Research. Methods in ... There is need to shade light on the basic terms used in the title of this paper. ..... examination of their theses and dissertations are frustrating due to the.
7. Standardization in measurement philosophical, historical and sociological issues
CERN Document Server
Schlaudt, Oliver
2015-01-01
The application of standard measurement is a cornerstone of modern science. In this collection of essays, standardization of procedure, units of measurement and the epistemology of standardization are addressed by specialists from sociology, history and the philosophy of science.
8. Evolutionary epistemology, rationality, and the sociology of knowledge
CERN Document Server
Bartley, W W
1993-01-01
This collection of essays in support of the theory of evolutionary epistemology includes articles by Karl Popper, Peter Munz and Gerhard Vollmer. This volume attempts to show how an evolutionary and non-justificational approach affects the sociology of knowledge.
9. Three General Theoretical Models in Sociology: An Articulated ?(Disunity?
Directory of Open Access Journals (Sweden)
Thaís García-Pereiro
2015-01-01
Full Text Available After merely a brief, comparative reconstruction of the three most general theoretical models underlying contemporary Sociology (atomic, systemic, and fluid it becomes necessary to review the question about the unity or plurality of Sociology, which is the main objective of this paper. To do so, the basic terms of the question are firstly updated by following the hegemonic trends in current studies of science. Secondly the convergences and divergences among the three models discussed are shown. Following some additional discussion, the conclusion is reached that contemporary Sociology is not unitary, and need not be so. It is plural, but its plurality is limited and articulated by those very models. It may therefore be portrayed as integrated and commensurable, to the extent that a partial and unstable (disunity may be said to exist in Sociology, which is not too far off from what happens in the natural sciences.
10. THE CULTURE AND ARTS ORGANIZATION: MACRO-SOCIOLOGICAL ASPECT
Directory of Open Access Journals (Sweden)
Margarita Rasimovna Pashaeva
2013-11-01
Full Text Available In this study we analyze the macro-sociological aspect of culture and arts organization. The subject of research is reputation policy and communication technologies in macro-sociological aspect of culture and arts organization. The target is the research the effects of macro-sociological aspect in the activities of such organization. In the study were used such methods of research: theoretical study and synthesis; quantative method of elicitation: questionnaire; information processing methods of primary analysis; interpretation. The results of research can be applied in the activities of different culture and arts organization. The research identified the negative and positive tendencies in the context of the macro-sociological aspect.DOI: http://dx.doi.org/10.12731/2218-7405-2013-8-49
11. Sociology and Complexity Science A New Field of Inquiry
CERN Document Server
Castellani, Brian
2009-01-01
This book is the first to identify and review the new field of study, sociology and complexity science—or SACS for short. SACS is comprised of five cutting-edge areas of research: computational sociology, the British-based School of Complexity (BBC), complex social network analysis (CSNA), sociocybernetics and the Luhmann School of Complexity (LSC). Together, these five areas represent the latest development in complexity science and sociological systems thinking, offering researchers a powerful, new set of tools for addressing the growing complexity of sociological inquiry. This book also showcases a new method for modeling social systems, called the SACS Toolkit. The SACS Toolkit comes with a theoretical framework (social complexity theory), procedural algorithm (assemblage) and recommended toolset for modeling social systems (qualitatively, historically or numerically) from the ground-up. In fact, this book uses the SACS Toolkit to review the new field of SACS. The third feature of this book is its compe...
12. Negation and Affirmation: a critique of sociology in South Africa
African Journals Online (AJOL)
2013-12-17
Dec 17, 2013 ... Eurocentrism, sociology of religion, inter-religious dialogue, Ibn. Khaldun, paper read at ... Unpublished Master's Thesis. University of South Africa. ... Journal of Investigative Psychology, 1(3): 191-206. Lebakeng, T.J., 2000.
13. Language practice as games: Implications for sociology of ...
African Journals Online (AJOL)
Language practice as games: Implications for sociology of translation in development contexts in Africa. ... Abstract. Drawing from Game Theory, the article conceptualises language practice as games, that is ... AJOL African Journals Online.
14. Johann Graaff. What is Sociology? Cape Town. Oxford University ...
African Journals Online (AJOL)
15. Representation and integration of sociological knowledge using knowledge graphs
NARCIS (Netherlands)
Popping, R; Strijker, [No Value
1997-01-01
The representation and integration of sociological knowledge using knowledge graphs, a specific kind of semantic network, is discussed. Knowledge it systematically searched this reveals. inconsistencies, reducing superfluous research and knowledge, and showing gaps in a theory. This representation
16. [Margot Jefferys: the British voice of medical sociology].
Science.gov (United States)
Nunes, Everardo Duarte
2011-03-01
Margot Jefferys (1916-1999) was not only the person who introduced medical sociology into Great Britain, but also the researcher and professor who, during thirty years, exerted the most deep influence on the teaching of health social sciences either in undergraduate or especially graduate studies, since the beginning of her career, in 1953, at the London School of Hygiene and Tropical Medicine. In addition to create a global panorama concerning the Jefferys' works, this study highlights two texts, which are situated into the field we are researching: the history of health sociology. The first one, published in 1991, discusses the relationships between epidemiology and sociology; and the second, published in 1996, discusses the field of medical sociology. Both texts are a series of considerations regarding the Jefferys' thought and the more recent questions of the field in Great Britain.
17. What has become of critique? Reassembling sociology after Latour.
Science.gov (United States)
Mills, Tom
2017-09-06
This paper offers a defence of sociology through an engagement with Actor Network Theory (ANT) and particularly the critique of 'critical' and politically engaged social science developed by Bruno Latour. It argues that ANT identifies some weaknesses in more conventional sociology and social theory, and suggests that 'critical' and 'public' orientated sociologists can learn from the analytical precision and ethnographic sensibilities that characterize ANT as a framework of analysis and a research programme. It argues, however, that Latour et al. have too hastily dispensed with 'critique' in favour of a value neutral descriptive sociology, and that the symmetrical and horizontalist approach adopted in ANT is particularly ill-suited to the development of scientific knowledge about social structures. It argues that a more straightforwardly realist sociology would share many of the strengths of ANT whilst being better able to interrogate, empirically and normatively, the centres of contemporary social power. © London School of Economics and Political Science 2017.
18. Dream homes and dead ends in the city: a photo essay experiment.
Science.gov (United States)
Fast, Danya
2017-09-01
Research focused on the relationship between place and health demonstrates that it is complex and shifting, as overlapping social, historical, institutional and political and economic processes continually transform the landscapes in which lived experiences are embedded. Understanding this relationship requires knowledge of the situated meanings and local worlds that ethnographic methods are well suited to investigate. However, even conventional ethnographic methods can be inadequate to capture the embodied, lived experience of place - experiences in which the sensory and inner processes of memory and imagination are often privileged. Accessing these experiences and processes can require more experimental methodological approaches. In this article, I present work from a series of photo essays created between 2011 and 2016 by 15 young people who inhabit the social, spatial and economic margins of Vancouver, Canada, and discuss some of the challenges and opportunities presented by this methodology. Created over 5 years, and broadly focused on how they understood, experienced and navigated their 'place' in the city in the midst of poverty, addiction, violence and physical and mental health crises, the photo essays young people produced are embedded with personal biographies and trajectories, as well as shared experiences of geography, precarity and possibility in Vancouver. © 2017 Foundation for the Sociology of Health & Illness.
19. Sociología y alimentación
Directory of Open Access Journals (Sweden)
Díaz Méndez, Cecilia
2005-04-01
Full Text Available This work presents briefly the relationship between sociology and food matters. In the first place, we point out some of the reasons by which we might explain why sociology has only lately started to systematically tackle this aspect of social life and we also point out what conditions have brought about this recent interest of this discipline in food. Secondly, we include an outline of the attention paid to food by some of the most important sociology scholars. Then we present an outline of the main theories underlying food sociology (and anthropology and we end up with a proposal to define the field of food sociology, starting from the analysis of the content of some of the most important current works on the sociology of food.
En este trabajo, se exponen las relaciones entre la sociología y el fenómeno alimentario. En primer lugar, se apuntan algunas de las razones que podrían explicar el retraso con que la sociología se ha ocupado de forma sistemática de este ámbito de la vida social y las condiciones que han despertado el interés reciente de esta disciplina por el fenómeno alimentario. En segundo lugar, se presenta un esquema de la atención prestada por los clásicos de la sociología a la alimentación, de modo que se pueda contrastar la naturaleza de esta atención con el análisis sociológico actual. En tercer lugar, se presenta un esquema de las principales orientaciones teóricas que han marcado la sociología (y la antropología de la alimentación, para terminar con una propuesta de definición del campo de la sociología de la alimentación a partir de la consideración de los contenidos de algunos textos actuales de este campo de estudio.
20. Eating Cities
DEFF Research Database (Denmark)
Mikkelsen, Bent Egberg; Fisker, Anna Marie; Clausen, Katja Seerup
2016-01-01
This paper analyzed the development of a city based sustainable food strategy for the city of Aalborg. It’s based on 3 cases of food service: food for the elderly as operated by the Municipality, food the hospital patients as operated by the region and food for defense staff as operated...
1. Sociological and ethical issues in transplant commercialism.
Science.gov (United States)
Epstein, Miran
2009-04-01
'Global transplant commercialism' (practices and policies involving international trade in organs from living vendors, e.g., 'transplant tourism') is currently subjected to unprecedented criticism. In parallel, the debate around 'local transplant commercialism' (practices and policies that confine trade in organs from living vendors to national markets or economic unions) is heating up. In an attempt to assess the potential outcomes of these trends, this article reviews and discusses some sociological and ethical issues, ending with a proposal for a reinvigorated anticommercialist strategy. The current international campaign against global transplant commercialism is conducted by an ad hoc alliance between strange bedfellows, proponents of local transplant commercialism on the one hand and opponents of any transplant commercialism on the other. Disparities in the rigor of the respective ethical discourses, the expanding list of precedents of legitimized commerce in the human body, and the political economy of transplantation, all suggest that the former have the upper hand. Recent achievements in the struggle against international organ trafficking may not herald the abolition of transplant commercialism but rather presage its reconfiguration in deglobalized forms. In light of such a prospect, those who wish to prevent the pervasive commodification of the human body from entering the gates of transplant medicine should consider devising a new, perhaps more radical, strategy.
2. The History and Sociology of Nutrition
Directory of Open Access Journals (Sweden)
Yuri V. Veselov
2016-10-01
Full Text Available The article is devoted to the history and sociology of food in the context of discussion about Boris Mironov’s monograph, “The Russian Empire: From Tradition to Modernity.” According to Veselov, Mironov was among the first researchers to study nutrition in Russian history. For the first time in Russian historiography, he analyzed the fundamentally important questions of the nutrition of all social classes in the period of the Empire from the point of view of quantity, quality, and conformity with the physiological needs of human beings. Veselov considers that Mironov’s approach has an integrative and systematic character. It is not limited to the study of cultural practices and rituals, or to the symbolic meanings of food. Mironov also analyzes what, when, and how much people ate, evaluates the adequacy of nutrition, its impact on human health and labor efficiency, and also the modernization of consumption. Veselov suggests that Mironov’s findings, according to which the nutrition of the urban and rural population in the Imperial period was more or less satisfactory, are thoroughly and convincingly substantiated, and that this became possible due to the fact that the modernization of consumption and production of food products took place in close interaction.
3. The inner magnetosphere imager mission
International Nuclear Information System (INIS)
Johnson, L.; Herrmann, M.
1993-01-01
After 30 years of in situ measurements of the Earth's magnetosphere, scientists have assembled an incomplete picture of its global composition and dynamics. Imaging the magnetosphere from space will enable scientists to better understand the global shape of the inner magnetosphere, its components and processes. The proposed inner magnetosphere imager (IMI) mission will obtain the first simultaneous images of the component regions of the inner magnetosphere and will enable scientists to relate these global images to internal and external influences as well as local observations. To obtain simultaneous images of component regions of the inner magnetosphere, measurements will comprise: the ring current and inner plasma sheet using energetic neutral atoms; the plasmasphere using extreme ultraviolet; the electron and proton auroras using far ultraviolet (FUV) and x rays; and the geocorona using FUV. The George C. Marshall Space Flight Center (MSFC) is performing a concept definition study of the proposed mission. NASA's Office of Space Science and Applications has placed the IMI third in its queue of intermediate-class missions for launch in the 1990's. An instrument complement of approximately seven imagers will fly in an elliptical Earth orbit with a seven Earth Radii (R E ) altitude apogee and approximately 4,800-kin altitude perigee. Several spacecraft concepts were examined for the mission. The first concept utilizes a spinning spacecraft with a despun platform. The second concept splits the instruments onto a spin-stabilized spacecraft and a complementary three-axis stabilized spacecraft. Launch options being assessed for the spacecraft range from a Delta 11 for the single and dual spacecraft concepts to dual Taurus launches for the two smaller spacecraft. This paper will address the mission objectives, the spacecraft design considerations, the results of the MSFC concept definition study, and future mission plans
4. Colour attitude test: the possibility of application in sociology
OpenAIRE
V P Tkach
2009-01-01
The article provides the analysis of the cognitive potential of colour tests in sociology. Nowadays colour tests which are extensively used in the framework of psychology find practically no application in sociological research due to a number of their peculiarities. However, it should be recognized that such tests as colour attitude test demonstrate the richest cognitive potential for the identification of value preferences and social attitudes system at the level of the unconscious of vario...
5. G. H. Mead in the History of Sociological Ideas
OpenAIRE
Silva, Filipe Carreira da
2006-01-01
My aim is to discuss the history of the reception of George Herbert Mead’s ideas in sociology. After discussing the methodological debate between presentism and historicism, I address the interpretations of those responsible for Mead’s inclusion in the sociological canon: Herbert Blumer, Jürgen Habermas, and Hans Joas. In the concluding section, I as- sess these reconstructions of Mead’s thought and suggest an alternative more consistent with my initial methodological remarks. In particular, ...
6. PHENOMENOLOGICAL INTERPRETATION OF BIOETHICAL REALITY (THE SOCIOLOGICAL ANALYSIS)
OpenAIRE
Nikulina Marina Alekseevna
2012-01-01
The interpretation of social reality is a classical problem of sociology, which solution helps perception and understanding of social phenomena. In the article phenomenological interpretation of bioethical reality is shown. Phenomenological sociology, being one of the perspective directions of development of social knowledge, it is characterized by aspiration to show «artificial», that is designed, nature of bioethical reality, its semantic structure, and thus, to «humanize» bioethical realit...
7. The Hidden Battle that Shaped the History of Sociology
DEFF Research Database (Denmark)
Thomassen, Bjørn
2016-01-01
This article engages the so far neglected intellectual dispute between Emile Durkheim and Arnold van Gennep. It revisits the most salient points of van Gennep’s critique of Durkheim’s sociology, especially as relates to the study of religion. In this context, the article also discusses the possible...... influence of van Gennep’s work on Marcel Mauss. The article ends by indicating why a revisitation of van Gennep’s critique of Durkheim might matter for contemporary sociology....
8. A sociological Analysis on the Modes of Science Production
Directory of Open Access Journals (Sweden)
Ali Rabbani Khorasgani
2012-12-01
Full Text Available The main aim of this article was sociological Analysis on the modes of science, survey of new Approaches in this context, description of available Approaches relevant to Application of Indigenous paradigm in prodvetion of knowledge and conclusion to attain imitated Approaches from Analysis and mentioned discussions for planning in space of science production in society of Iran. After Analysis of propound Approaches in sociology of science concreted that sociology of science three generation transitioned yet : classic sociology of science (OSS [ Theories of Merton ] , New sociology of science ( NSS [Theories of Thomas kuhn and others ] and Third generation sociology of science that consisted of non - Marxist composinal and processive Approaches for example: Actor - Network theory (ANT, Triple Helix Theory life eyeles, mode 2 and Mode 3. On the other hand , because science production is encompass process in social structures and social communications , allowance for Analysis of Recent Development in mode of science production , three paradigm Analysis and critiqued titles mode 1 , 2 , 3 production of knowledge . Also, Application of Indigenous paradigm studied in production of knowledge and introduced two groups: A - External Approaches B - Internal Approaches that each of two groups propounded Ideas relevant to Indigenous knowledge and Indigenization of knowledge. In the final section, mode an efforted to answered this question that what doctrines can be concluded from these discourse in order to improve the conditions in Iran.
9. Uma sociologia do business na capital mexicana A sociology of "business" in the Mexican capital
Directory of Open Access Journals (Sweden)
Johana Parra
2010-12-01
10. Eco2 Cities : Ecological Cities as Economic Cities
OpenAIRE
Suzuki, Hiroaki; Dastur, Arish; Moffatt, Sebastian; Yabuki, Nanae; Maruyama, Hinako
2010-01-01
This book provides an overview of the World Bank's Eco2 cities : ecological cities as economic cities initiative. The objective of the Eco2 cities initiative is to help cities in developing countries achieve a greater degree of ecological and economic sustainability. The book is divided into three parts. Part one describes the Eco2 cities initiative framework. It describes the approach, be...
11. Creating sustainable city by enhancing social capital
Science.gov (United States)
Affandi, R. A.; Mursitama, T. N.
2018-03-01
Scholars have been discussing social capital since the last two decades. They analyzed from various perspectives such as sociology, education, political participation, strengthening democratic values and economic empowerment of the society. However, study related to the implementation that benefits directly to the society is needed. This study examines how to create a sustainable city by enhancing social capital from both macro and micro analyses. This combination of analysis offers deeper understanding both from decision makers at city level and individuals, groups and society. We will conduct qualitative approach mainly by interviews and direct observation to collect the data. also, we also analyze publicly available data. Finally, this study contributes to new understanding in creating a sustainable city, not only about the environment and physical aspects, but also about ensuring political economic, democratic values, and social welfare.
12. Sociología de la salud en México Medical Sociology in Mexico
Directory of Open Access Journals (Sweden)
Roberto Castro
2011-09-01
Full Text Available
En este trabajo se realiza un análisis del campo de la sociología médica en México en los últimos 30 años. Se inicia con una descripción de las tres escuelas que fundaron el campo en este país: a la antropología médica, de larga tradición en este país, anclada en la Escuela Nacional de Antropología e Historia, el Instituto de Investigaciones Antropológicas (UNAM, y el Centro de Investigaciones y Estudios Superiores en Antropología Social;b la medicina social, impulsada principalmente desde la Universidad Autónoma Metropolitana-Xochimilco, y que tuvo como punto de partida la creación de la Maestría en Medicina Social en 1975; y c la sociología de la salud pública, impulsada desde el Instituto Nacional de Salud Pública a partir de su fundación en 1987. Tras revisar los principales aportes de cada corriente, así como los debates más importantes que tuvieron lugar entre ellas –y que sirvieron para delimitar el espacio de acción e influencia de cada una– se describen los desarrollos más trascendentes en este campo, mismos que contribuyeron a desarrollar la “segunda generación” de la sociología médica mexicana. Dentro de esta segunda generación, se señalan las principales contribuciones de orden teórico, metodológico y sustantivo. Éstas últimas, a su vez, se dividen en áreas específicas: salud reproductiva, violencia contra las mujeres, subjetividad y salud, y políticas, práctica médica y utilización de servicios de salud.
In this paper the field of medical sociology in México during the last 30 years is analyzed. First, a description is made of the three founding schools in this country: a the tradition of medical anthropology, based on the National School of Anthropology and History, the Institute of Anthropological Research (National Autonomous University of Mexico, and the Center of Research and Graduate Studies in Social Anthropology; b the tradition of social medicine, prompted by the
13. Flying Cities
DEFF Research Database (Denmark)
Ciger, Jan
2006-01-01
The Flying Cities artistic installation brings to life imaginary cities made from the speech input of visitors. In this article we describe the original interactive process generating real time 3D graphics from spectators' vocal inputs. This example of cross-modal interaction has the nice property....... As the feedback we have received when presenting Flying Cities was very positive, our objective now is to cross the bridge between art and the potential applications to the rehabilitation of people with reduced mobility or for the treatment of language impairments....
14. Flying Cities
DEFF Research Database (Denmark)
Herbelin, Bruno; Lasserre, Sebastien; Ciger, Jan
2008-01-01
Flying Cities is an artistic installation which generates imaginary cities from the speech of its visitors. Thanks to an original interactive process analyzing people's vocal input to create 3D graphics, a tangible correspondence between speech and visuals opens new possibilities of interaction....... This cross-modal interaction not only supports our artistic messages, but also aims at providing anyone with a pleasant and stimulating feedback from her/his speech activity. As the feedback we have received when presenting Flying Cities was very positive, our objective is now to cross the bridge between art...
15. Social Change and Sport: A Sociological Evaluation
Directory of Open Access Journals (Sweden)
Yılmaz KAPLAN
2013-12-01
Full Text Available This study aims to discuss the relation between social change and sports from a sociological point of view. This study is descriptive in its aim, periodic (discussion in the length of time it covers and theoretical based on literature in its techniqu e. “Social change” is a value judgement - free concept which does not indicate a direction but determines the new situation, the difference occurring in the society compared to the former era or situation. Every society changes in time; however, it cou ld at times be „‟positive‟‟ (in the direction of development, progress, etc... and „‟negative‟‟ at other times (in the direction of regress, deconstruction, etc.... As a social institution, sport, while affecting some social institutions (family, edu cation, economics, politics, religion, communication, healthcare, law, is also affected by them. The process of social change has affected, moreover, has determined sports. As a social event, phenomenon, and institution, sports gains its meaning in the society that it takes place; and it both gets affected by the changes in the society and affects these changes there. It could be the „‟reason‟‟ and the „‟result‟‟ of social changes. Radical changes in the sports and even in the rules of branche s of sports are made depending on the changing social needs, preferences and expectations. Although there isn‟t an obligatory relation between „‟social progress‟‟ and „‟sports‟‟ theoretically, it can be said that the process of social progress contributes to sports and vice versa.
16. Imaging of the inner ear
International Nuclear Information System (INIS)
Casselman, J.W.; Bensimon, J.L.
1997-01-01
New computed tomography (CT) and magnetic resonance (MR) techniques allow more detailed anatomic studies of the inner ear. CT is still the best technique to study patients with fractures, congenital malformations and otodystrophies involving the inner ear. During recent years MR imaging has emerged as an excellent method to detect pathology in the internal auditory canal, membranous labyrinth and bony labyrinth and to characterize petrous apex lesions. MR has even proved its value in patients with fractures and congenital malformations making the diagnosis of, for instance, labyrinthine concussion and absence of the vestibulocochlear nerve possible. The diagnosis of acute/chronic labyrinthitis and intralabyrinthine tumors has also became possible. However, MR and CT are often complementary, as is the case in patients with mixed hearing loss, congenital malformations and petrous apex lesions. (orig.) [de
17. Por una sociología pública Por una sociología pública
Directory of Open Access Journals (Sweden)
Michael Burawoy
2005-09-01
Full Text Available Responding to the growing gap between the sociological ethos and the world we study, the challenge of public sociology is to engage multiple publics in multiple ways. These public sociologies should not be left out in the cold, but brought into the framework of our discipline. In this way we make public sociology a visible and legitimate enterprise, and, thereby, invigorate the discipline as a whole. Accordingly, if we map out the division of sociological labor, we discover antagonistic interdependence among four types of knowledge: profes- sional, critical, policy, and public. In the best of all worlds the flourishing of each type of sociology is a condition for the flourishing of all, but they can just as easily assume pathological forms or become victims of exclusion and subordination. This field of power beckons us to explore the relations among the four types of sociology as they vary historically and nationally, and as they provide the template for divergent individual careers. Finally, comparing disciplines points to the umbilical chord that connects sociology to the world of publics, underlining sociology’s particular interest in the defense of civil society, itself beleaguered by the encroachment of markets and states.En respuesta a la creciente separación entre el ethos sociológico y el mundo que estudiamos, el desafío para la sociología pública son las diferentes formas en las que comprometerse con sus públicos. Estas sociologías públicas no deberían estar en los márgenes sino que deberían formar parte del marco de trabajo de nuestra disciplina. De esta manera haremos de la sociología pública una empresa legítima y visible y, por ende, reforzaremos en todo su conjunto a nuestra disciplina. Según esto, si observamos la división del trabajo sociológico, descubriremos una interdependencia antagónica entre cuatro tipos de conocimiento, a saber: profesional, crítico, práctico y público. En el mejor de los mundos
18. City Streets
Data.gov (United States)
Minnesota Department of Natural Resources — This data set contains roadway centerlines for city streets found on the USGS 1:24,000 mapping series. In some areas, these roadways are current through the 2000...
19. ELEMENTS FOR A SOCIOLOGICAL ANALYSIS OF HERITAGE POLICIES IN SOUTH BRAZIL: CULTURE, TOURISM AND DEVELOPMENT
Directory of Open Access Journals (Sweden)
Rodrigo Manoel Dias da Silva
2016-05-01
Full Text Available This article analyzes the contemporary condition of heritage policies in cities tumbled by official organ tipping considering in sociological perspective, the multiple mediations that affect the social goals deposited in them. The theoretical and empirical analysis presented, culture, tourism and development in shape important for the design of a theoretical approach to the phenomenon interpretative elements. The author concludes that, ambivalently, such policies intersect with social processes of identity affirmation of individuals and groups in the heritage landscape of cultural productions and at the same time, with narratives that allow the heritage of the place "resource" to programs of social development and revitalization of tourism and economic circuits in the region.
20. Para una sociología de la sexualidad
Directory of Open Access Journals (Sweden)
OSCAR GUASCH
1993-01-01
Full Text Available La sociología deja la sexualidad en manos del psicoanálisis y de la medicina, primero, y de la sexología, después. La sociología de la sexualidad comparte objeto de estudio con otras especializaciones de la disciplina como la sociología de la familia o la sociología del género. El objeto de estudio de la sociología de la sexualidad es el sexo: el sexo en tanto que actividad social. Se ocupa de definir que es sexo y que no lo es, describe que espacios y tiempos tiene adjudicados, que actores lo ejecutan y cuales no, de que modo lo hacen, y las razones y consecuencias sociales de todo ello. En este artículo se define el marco sociohistórico que deben tener en cuenta futuras investigaciones sociológicas sobre sexualidad, revisando los distintos modos mediante los cuales occidente organiza el control social de la actividad sexual.
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https://documen.tv/question/in-a-sample-of-oygen-gas-at-room-temperature-the-average-kinetic-energy-of-all-the-balls-stays-c-24003142-16/
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## In a sample of oxygen gas at room temperature, the average kinetic energy of all the balls stays constant. Which postulate of kinetic molecu
Question
In a sample of oxygen gas at room temperature, the average kinetic energy of all the balls stays constant. Which postulate of kinetic molecular theory best explains
how this is possible?
Attractive forces between gas particles are negligible because the particles of an ideal gas are moving so quickly
O Collisions between gas particles are elastic, there is no net gain or loss of kinetic energy
Gases consist of a large number of small particles, with a lot of space between the particles
O Gas particles are in constant, random motion, and higher kinetic energy means faster movement
in progress 0
2 months 2021-07-22T19:29:57+00:00 1 Answers 10 views 0
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https://proofwiki.org/wiki/Power_of_Identity_is_Identity
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Power of Identity is Identity
Theorem
Let $\struct {M, \circ}$ be a monoid whose identity element is $e$.
Then:
$\forall n \in \Z: e^n = e$
Proof
Since $e$ is invertible, the power of $e$ is defined for all $n \in \Z$.
We prove the case $n \ge 0$ by induction.
Basis for the Induction
By definition of power of monoid element:
$e^0 = e$
so the theorem holds for $n = 0$.
This is our basis for the induction.
Induction Hypothesis
Our induction hypothesis is that the theorem is true for $n = k$:
$e^k = e$
Induction Step
In the induction step, we prove that the theorem is true for $n=k+1$.
We have:
$\displaystyle e^{k + 1}$ $=$ $\displaystyle e^k \circ e$ Definition of Power of Element of Monoid $\displaystyle$ $=$ $\displaystyle e^k$ Definition of Identity Element $\displaystyle$ $=$ $\displaystyle e$ Induction Hypothesis
Therefore, by Principle of Mathematical Induction:
$\forall n \in \Z_{\ge 0} : e^n = e$
$\Box$
Now we prove the case $n < 0$.
We have:
$\displaystyle e^n$ $=$ $\displaystyle \paren {e^{-n} }^{-1}$ Definition of Power of Element of Monoid $\displaystyle$ $=$ $\displaystyle e^{-1}$ since $-n > 0$ $\displaystyle$ $=$ $\displaystyle e$ Inverse of Identity Element is Itself
Thus:
$\forall n \in \Z : e^n = e$
$\blacksquare$
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https://www-fourier.univ-grenoble-alpes.fr/?q=fr/content/generalization-kolyvagins-trace-relations
|
100, rue des maths 38610 Gières / GPS : 45.193055, 5.772076 / Directeur : Louis Funar
# Generalization of Kolyvagin's trace relations.
Mercredi, 14 Décembre, 2005 - 15:00
Prénom de l'orateur :
Dmitry
Nom de l'orateur :
LOGACHEV
Résumé :
In 1989 -- 1991 Kolyvagin proved finiteness of Tate -- Shafarevich group of elliptic curves $E$ over $Bbb Q$ of analytic rank 0 and 1 which are quotients
of modular curves $X_0(N)$. There is a natural problem to extend this result to the case when an analog of $X_0(N)$ is any Shimura variety $X$, and an analog of $E$ is a quotient motive of some $H^i(X)$.
The purpose of the present series of lectures is to consider some particular steps of this general problem. No preliminary knowledge of the original Kolyvagin's proof is necessary, a survey of the proof will be given. The whole subject contains a lot of open problems, some cases are not treated completely yet. These reseach problems will be stated explicitly. Since the technique of solution of these problems in some cases is reduced to elementary matrix calculations, the subject can be
interesting for young researchers.
Trace relations describe the image of the action of a Hecke correspondence $T_p$ on a subvariety $V$ of a Shimura variety $X$. We find irreducible components of $T_p(V)$
and Galois action on them. Firstly, we give an answer in terms of reductive groups $G_X$, $G_V$ defining $X$, $V$ respectively. It is not clear beforehand thatthe original formulas are suitable for calculations.
We consider the case when $X$ is a Siegel variety of any genus $g$ and $V$ its subvariety parametrizing abelian $g$-folds with multiplication by an imaginary
quadratic field, i.e. we have $G_X=GSp_{2g}$ and $G_V=GU(r,s)$, $r+s=g$.
Further, we show how to apply the general formulas to this situation. The results have a simple geometric interpretation in terms of geometry of some Grassmann
variety over $Bbb F_p$. Practically, we define some partitions on these varieties.
ATTENTION: horaire exceptionnel.
Institution de l'orateur :
Universidad Simón Bolívar (Caracas, Venezuela
Thème de recherche :
Théorie des nombres
Salle :
04
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http://weblib.cern.ch/collection/ALICE%20Preprints?ln=sk&as=1
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# ALICE Preprints
Posledne pridané:
2022-11-24
04:02
Real and virtual direct photon measurements with ALICE / Scheid, Sebastian In this contribution the latest measurements of real and virtual photons in Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV from the ALICE Collaboration are presented. [...] arXiv:2211.11934. - Fulltext
2022-11-23
19:35
Multiplicity dependence of charged-particle production in pp, p-Pb, Xe-Xe and Pb-Pb collisions at the LHC / ALICE Collaboration, CERN Multiplicity ($N_{\mathrm {ch}}$) distributions and transverse momentum ($p_{\mathrm T}$) spectra of inclusive primary charged particles in the kinematic range of $|\eta| < 0.8$ and 0.15 GeV/$c$ $< p_{\mathrm T} < 10$ GeV/$c$ are reported for pp, p-Pb, Xe-Xe and Pb-Pb collisions at centre-of-mass energies per nucleon pair ranging from $\sqrt{s_\mathrm{NN}} = 2.76$ TeV up to 13 TeV. A sequential two-dimensional unfolding procedure is used to extract the correlation between the transverse momentum of primary charged particles and the charged-particle multiplicity of the corresponding collision. [...] CERN-EP-2022-266.- Geneva : CERN, 2022 Draft (restricted): PDF;
2022-11-23
04:30
Exploring jet interactions in the quark-gluon plasma using jet substructure measurements in Pb-Pb collisions with ALICE / Ehlers, Raymond Jets are generated in hard interactions in high-energy nuclear collisions. [...] arXiv:2211.11800. - 6 p. Fulltext
2022-11-23
04:27
Commissioning and first performances of the ALICE MID RPCs / Terlizzi, Livia ALICE (A Large Ion Collider Experiment) at the CERN Large Hadron Collider (LHC) is designed to study p-p and Pb-Pb collisions at ultra-relativistic energies. [...] arXiv:2211.11254. - Fulltext
2022-11-18
22:59
Enhanced deuteron coalescence probability in jets / ALICE Collaboration, CERN /ALICE The transverse-momentum ($p_{\rm T}$) spectra and coalescence parameters $B_2$ of (anti)deuterons are measured in pp collisions at $\sqrt{s} = 13$ TeV in and out of jets. In this measurement, the direction of the leading particle with the highest $p_{\rm T}$ in the event ($p_{\rm T}^{\rm{ lead}} > 5$ GeV/$c$) is used as an approximation for the jet axis [...] CERN-EP-2022-264; arXiv:2211.15204.- Geneva : CERN, 2022 - 11 p. Draft (restricted): PDF; Fulltext: PDF;
2022-11-18
19:07
Light (anti)nuclei production in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV / ALICE Collaboration, CERN /ALICE The measurement of the production of deuterons, tritons and ${^{3}\mathrm{He}}$ and their antiparticles in Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV is presented in this article. The measurements are carried out at midrapidity ($|y| < 0.5$) as a function of collision centrality using the ALICE detector. [...] CERN-EP-2022-263; arXiv:2211.14015.- Geneva : CERN, 2022 - 16 p. Draft (restricted): PDF; Fulltext: PDF;
2022-11-18
14:29
Pseudorapidity densities of charged particles with transverse momentum thresholds in pp collisions at $\sqrt{s}=$ 5.02 and 13 TeV / ALICE Collaboration, CERN The pseudorapidity density of charged particles with minimum transverse momentum ($p_{\rm T}$) thresholds of 0.15, 0.5, 1, and 2 GeV$/c$ was measured in pp collisions at centre-of-mass energies of $\sqrt{s}=$ 5.02 and 13 TeV with the ALICE detector. The study is carried out for inelastic collisions with at least one primary charged particle having a pseudorapidity ($\eta$) within $\pm0.8$ and $p_{\rm T}$ larger than the corresponding threshold [...] CERN-EP-2022-262.- Geneva : CERN, 2022 Draft (restricted): PDF;
2022-11-18
13:54
First measurement of $\mathbf{\Lambda}_\mathbf{c}^\mathbf{+}$ production down to $p_\mathbf{T} = \mathbf{0}$ in pp and p-Pb collisions at $\sqrt{s_\mathbf{NN}}= \mathbf{5.02 TeV}$ / ALICE Collaboration, CERN The production of prompt ${\mathrm {\Lambda_{c}^{+}}}$ baryons has been measured at midrapidity in the transverse momentum interval $0 < p_{\rm T} < 1$ GeV/$c$ for the first time, in pp and p-Pb collisions at a centre-of-mass energy per nucleon-nucleon collision $\sqrt{s_\mathrm{NN}} = 5.02$ TeV. The measurement was performed in the decay channel $\mathrm{\rm \Lambda_{c}^{+} \to p K^{0}_{S}}$ by applying new decay reconstruction techniques using a Kalman-Filter vertexing algorithm and adopting a machine-learning approach for the candidate selection. [...] CERN-EP-2022-261; arXiv:2211.14032.- Geneva : CERN, 2022 - 21 p. Draft (restricted): PDF; Fulltext: PDF;
2022-11-17
04:09
Two-particle transverse momentum correlations in pp and p-Pb collisions at LHC energies / Collaboration, Alice Two-particle transverse momentum differential correlators, recently measured in Pb-Pb collisions at LHC energies, provide an additional tool to gain insights into particle production mechanisms and infer transport properties, such as the ratio of shear viscosity to entropy density, of the medium created in Pb-Pb collisions. [...] CERN-EP-2022-230 ; arXiv:2211.08979. - 21 p. Fulltext
2022-11-17
04:09
Production of ${\rm K}^{0}_{\rm{S}}$, $\Lambda$ ($\bar{\Lambda}$), $\Xi^{\pm}$ and $\Omega^{\pm}$ in jets and in the underlying event in pp and p$-$Pb collisions The production of strange hadrons (K$^{0}_{\rm S}$, $\Lambda$, $\Xi^{\pm}$, and $\Omega^{\pm}$), baryon-to-meson ratios ($\Lambda/{\rm K}^{0}_{\rm S}$, $\Xi/{\rm K}^{0}_{\rm S }$, and $\Omega/{\rm K}^{0}_{\rm S}$), and baryon-to-baryon ratios ($\Xi/\Lambda$, $\Omega/\Lambda$, and $\Omega/\Xi$) associated with jets and the underlying event were measured as a function of transverse momentum ($p_{\rm T}$) in pp collisions at $\sqrt{s} = 13$ TeV and p-Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV with the ALICE detector at the LHC. [...] CERN-EP-2022-218 ; arXiv:2211.08936. - 28 p. Fulltext
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https://www.enotes.com/homework-help/topic/calculus1
|
# Calculus
• Calculus
We have the function y = e^ln(x^x) take the log of both the sides ln y = ln (e^ln(x^x)) => ln y = ln(x^x) => ln y = x*ln x differentiate both the sides (1/y)dy/dx = ln x + x/x dy/dx = y*(ln x...
• Calculus
We have to determine the definite integral of y = sin 2x /sqrt(1 + (sin x)^4), x = 0 to x = pi/2 Int [ sin 2x /sqrt(1 + (sin x)^4) dx] let 1 + (sin x)^2 = y dy/dx = 2*sin x* cos x = sin 2x => dy...
• Calculus
We have to integrate [1/ (y^2 + 8y + 20) dy] Int [1/( y^2 + 8y + 20) dy] => Int [ 1 / (y^2 + 8y + 16 + 4) dy] => Int [ 1/((y + 4)^2 + 2^2) dy] if u = y + 4 , dy = du => Int [ 1/ ( u^2 +...
• Calculus
We have to determine lim x-->0 [(2x - sin 2x)/x^3] If we substitute x = 0, we get the indeterminate form 0/0, so we use the l'Hopital's Rule and substitute the numerator and denominator with...
• Calculus
We are given that f(x)=1+2x^5/x^2 = 1 + 2x^3. We have to find: lim x -->1 [(f(x) - f(1))/(x-1)] => lim x -->1 [(1+ 2x^3 - 1 - 2)/(x-1)] => lim x -->1 [(2x^3 - 2)/(x-1)]\ => lim x...
• Calculus
We need to find the value of lim x-->0 [ tan 4x / tan 2x] If we substitute x = 0, we get the indeterminate form 0/0. This allows us to use l'Hopital's rule and substitute the numerator and the...
• Calculus
We have to find the value of lim x--> 0[ (sin 5x - sin 3x)/x] if we substitute x = 0, we get the form 0/0, which allows us to use the l'Hopital's rule and substitute the numerator and the...
• Calculus
We need to find the value of lim x--> pi/4 [sin x/(1- 2*(sin x)^2) - cos x/2*(cos x)^2 - 1) - sin 2x / cos x. Substituting x = pi/4, gives us an indeterminate value. lim x--> pi/4 [sin x/(1-...
• Calculus
The critical points are determined by differentiating the function and equating the derivative to 0. It is solved to determine x. f(x) = sin x + cos x f'(x) = cos x - sin x = 0 => cos x = sin...
• Calculus
We have to prove that lim x-->0 [(a^x - 1)/x] = ln a First, if we substitute x = 0, we get the indeterminate form 0/0. This allows the use of l"Hopital's rule and we can substitute the numerator...
• Calculus
You want the limit of y=(1-cos 2x)/x^2 while x approaches 0. y = (1-cos 2x)/x^2 => [1 - (1 - 2*(sin x)^2)]/x^2 => 2*(sin x)^2/x^2 => 2*(sin x / x)^2 lim x--> 0 (sin x / x) = 1 Using...
• Calculus
We need to determine the integral of (cos x)^7 * sin x. Int [(cos x)^7 * sin x dx] let cos x = u => - du = sin x dx => Int [ -u^7 du] => -u^8 / 8 + C substitute u = cos x => - (cos...
• Calculus
We have to determine the value of lim x--> 0[(cos x - cos 3x) / x*sin x If we substitute x = 0, we get (1- 1) / 0 = 0/0 As this is an indeterminate form we use l'Hopital's rule and replace the...
• Calculus
The extreme values of a function occur at the points where the derivative is equal to 0. f(x) = 2x^3 + 3x^2 - 12x + 5 => f'(x) = 6x^2 + 6x - 12 6x^2 + 6x - 12 = 0 => x^2 + x - 2 = 0 => x^2...
• Calculus
We have y=(1+x^2)^3 We have to find dy/dx. We can use the chain rule here. dy/dx = 3(1 + x^2)^2*2x => dy/dx = 6x(1 + x^2)^2 The required result is 6x*(1 + x^2)^2
• Calculus
First we need to determine the points of intersection between lnx and ln^2 x ==> ln x = ln^2 x ==> ln^2 x - ln x = 0 ==> lnx ( lnx -1) =0 ==> lnx = 0 ==> x = 1 ==> lnx-1 = 0...
• Calculus
We have to find the area enclosed between y=x^2 - 2x + 2 and y = -x^2 + 6. First lets find the points of intersection x^2 - 2x + 2 = -x^2 + 6 => 2x^2 - 2x - 4 = 0 => x^2 - x - 2 = 0 => x^2...
• Calculus
The area of the region bounded by the curve y = sqrt (x - 1), the y- axis and the lines y = 1 and y = 5 is the limited integral of the expression of x in terms of y, between y = 5 and y = 1. y =...
• Calculus
We have to verify that lim x-->0 [ ln(1+x)/x] = 1. substituting x = 0, we get the indeterminate form 0/0, therefore we can use the l'Hopital's rule and substitute the numerator and denominator...
• Calculus
We have the functions f(x) = 3x+ 2 and g(x) = x^2 + 1 u = fog ( x) = f(g(x)) => f(x^2 + 1) => 3(x^2 + 1) + 2 => 3x^2 + 3 + 2 => 3x^2 + 5 v = gof(x) = g(f(x)) => g( 3x + 2) => (3x...
• Calculus
We have to find the limit of f(x)=(sin x-cos x)/cos 2x for x--> 45 degrees. We know that cos 2x = (cos x)^2 - (sin x )^2 lim x--> 0 [(sin x-cos x)/cos 2x] => lim x--> 0 [(sin x-cos...
• Calculus
We have to find the value of (x^2+2x-3)/|x-1| as x approaches from the left. As x approaches from the left x - 1 is always negative, so we have |x - 1| = (1 - x) lim x--> 1 [ (x^2+2x-3)/(1 -...
• Calculus
We have dy/dx = 4x^3 + 4x. dy/dx = 4x^3 + 4x => dy = (4x^3 + 4x) dx Integrate both the sides Int [ dy ] = Int [ (4x^3 + 4x) dx ] => y = 4x^4 / 4 + 4*x^2 / 2 => y = x^4 + 2*x^2 + C As the...
• Calculus
We first determine the points where the curves y = 8 - x^2 and y = x^2, meet. 8 - x^2 = x^2 => x^2 = 4 => x = 2 , x = -2 Now we find the integral of 8 - x^2 - x^2 between the limits x = -2...
• Calculus
We have to find the value of lim h-->0[[(3+h)^2-9]/h] lim h-->0[[(3+h)^2-9]/h] => lim h-->0[[(3 + h - 3)(3 + h + 3)/(3 + h - 3)] cancel (3 + h - 3) => lim h-->0[[(3 + h + 3)]...
• Calculus
We have to find Int [1/ (1 + 4x^2) dx]. First substitute u = 2x => du /dx = 2 => du /2 = dx Now Int [1/ (1 + 4x^2) dx] => Int [(1/2)*(1/ (1+u^2) du] => (1/2)*Int [1/ (1 + u^2) du] Now...
• Calculus
We have to differentiate f(x) = x*cos 2x f'(x) = x'*cos 2x + x*(cos 2x)' f'(x) = cos 2x + x*(-sin 2x)*2 f'(x) = cos 2x - 2x*(sin 2x) The required derivative of f(x) = x*cos 2x is f'(x) = cos 2x -...
• Calculus
We have to find the value of the definite integral of x^2/sqrt (x^3 + 1) between the limits x = 2 and x = 3. First we determine the indefinite integral and then substitute the values x = 3 and x =...
• Calculus
To find the curve we integrate the given dy/dx = 3x^2 - 2x. Int [ 3x^2 - 2x dx ] => 3*x^3 / 3 - 2x^2 / 2 + C => x^3 - x^2 + C As the curve passes through (2 , 5) 5 = 2^3 - 2^2 + C => 5 =...
• Calculus
The function f(x) = x^(sin x) Let y = f(x) = x^(sin x) Take the natural log of both the sides ln y = ln [ x^(sin x)] => ln y = sin x * ln x Differentiate both the sides with respect to x =>...
• Calculus
We have to find the value of lim x--> 0 [ ln(1+x)/(sinx+sin3x)] substituting x = 0, we get the indeterminate form 0/0. Therefore we can use l'Hopital's Rule and substitute the numerator and...
• Calculus
Hi, djshan, Sorry, but I'm not too sure what you want us to do here. Are we going to graph this? Find the intercepts? Find the zeros? Something else? I would assume we are graphing it. To...
• Calculus
We have to find Int [e^2x * cos 3x dx] Here the best way to solve would be to use integration by parts. Int [u dv] = u*v – Int [v du] take u = e^2x, du = 2*e^2x dx dv = cos 3x dx, v = (1/3)* sin...
• Calculus
We have to find the antiderivative of y = x / sqrt ( x^2 - 9) Let u = x^2 - 9 => du / dx = 2x => x dx = du/2 Int [ x / sqrt ( x^2 - 9) dx] => Int [(1/2)*(1/ sqrt u) du] => Int [ (1/2)*...
• Calculus
We have to find y' for y = (2-x)^(sqrt x) Use natural logariths for both the sides ln y = ln[ (2-x)^(sqrt x)] use the property ln a^x = a*ln x => ln y = (sqrt x)*ln ( 2 - x) Do implicit...
• Calculus
To find the slant asymptote of x^3 / (x + 2)^2 we have to divide x^3 by (x + 2)^2 (x^2 + 4x + 4) | x^3...........................................| x - 4 ...........................x^3 + 4x^2 + 4x...
• Calculus
We have to find the derivative of y = arc sin x/(1-x^2). We use the quotient rule here: y' = [(arc sin x)'*(1 - x^2) - ( arc sin x)*(1 - x^2)']/(1 - x^2)^2 => [sqrt(1-x^2)*(1 - x^2) + 2x*(arc...
• Calculus
We have to find the value of lim x--> 90[ (1- sin x)/(cos x)^2] substituting x = 90 degrees, we get the indeterminate form 0/0, so we can use l'Hopital's rule and substitute the numerator and...
• Calculus
We have to find the derivative of y = (10 + lg (x^10) + e^10x)^10. We use the chain rule to find the derivative of y. y' = 10 * (10 + lg (x^10) + e^10x)^9 * (10 / x + 10*e^10x) => 10 * (10 + lg...
• Calculus
We have to find the integral of f'(x)=11e^x/(11+e^x) f'(x)=11e^x/(11+e^x) let 11 + e^x = y e^x dx = dy Int [ 11e^x/(11+e^x) dx] => Int [ 11dy/y] => 11*ln |y| + C substitute y = 11 + e^x =>...
• Calculus
We have the function y = sin x + cos 3x. The derivative of sin x is cos x and the derivative of cos x is -sin x. Also, for a function of the form y= f(g(x)), the derivative of y or y' is given by...
• Calculus
We have to find the integral of 1/(16x^2+24x+9) 1/(16x^2+24x+9) => 1/(4x+3)^2 let 4x + 3 = u => du/dx = 4 => dx = du/4 Int[ 1/(16x^2+24x+9) dx] => Int [ 1/u^2 du/4] => (1/4) Int [...
• Calculus
We have to find the value of lim x--> pi[ sin 5x / sin x] We see that substituting x with pi gives us the form 0/0 which is indeterminate. We can use therefore use l'Hopital's rule and use the...
• Calculus
We have f(x) = (3x + 1)*e^-x We use the product rule to find f'(x) f'(x) = (3x + 1)'*e^-x + (3x + 1)*(e^-x)' => 3*e^-x - (3x +1)e^-x => 3*e^-x - f(x) f''(x) = -3e^-x - f'(x) => -3e^-x -...
• Calculus
We need to find f(x) given that f'(x) = sin 2x /((sin x)^2 - 4) let ((sin x)^2 - 4) = y dy = 2*sin x * cos x dx =>dy = sin 2x dx Int [ sin 2x /((sin x)^2 - 4) dx] => Int [ 1/y dy] => ln...
• Calculus
We have to find lim x--> -2 [(x^2-2x-8)/(x^3+8)] using l'Hopital's rule. First we find out if the l'Hopital's Rule can be used here. Substituting x = -2 we get the indeterminate form 0/0;...
• Calculus
We have the function: f(x)=12x^4+24x^2+56 f(x) = 12x^4 + 24x^2 + 56 f'(x) = 48x^3 + 48x If f'(x) = 0 => 48x^3 + 48x = 0 => x^3 + 3 = 0 => x( x^2 + 1) = 0 x1 = 0 x2 = -sqrt (-1) => x2 =...
• Calculus
The area bound by the curve y = cosx/(sin^2x-4), the x axis and the lines x = 0 and x = pi/2 is the integral of y between the limits x = 0 and x = pi/2. y = cos x/ ((sin x)^2 - 4) let sin x = y...
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http://nrich.maths.org/public/leg.php?code=72&cl=3&cldcmpid=905
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Search by Topic
Resources tagged with Generalising similar to Squaring the Circle and Circling the Square:
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Broad Topics > Using, Applying and Reasoning about Mathematics > Generalising
Squaring the Circle and Circling the Square
Stage: 4 Challenge Level:
If you continue the pattern, can you predict what each of the following areas will be? Try to explain your prediction.
Polycircles
Stage: 4 Challenge Level:
Show that for any triangle it is always possible to construct 3 touching circles with centres at the vertices. Is it possible to construct touching circles centred at the vertices of any polygon?
A Tilted Square
Stage: 4 Challenge Level:
The opposite vertices of a square have coordinates (a,b) and (c,d). What are the coordinates of the other vertices?
Equilateral Areas
Stage: 4 Challenge Level:
ABC and DEF are equilateral triangles of side 3 and 4 respectively. Construct an equilateral triangle whose area is the sum of the area of ABC and DEF.
Semi-square
Stage: 4 Challenge Level:
What is the ratio of the area of a square inscribed in a semicircle to the area of the square inscribed in the entire circle?
Tilted Squares
Stage: 3 Challenge Level:
It's easy to work out the areas of most squares that we meet, but what if they were tilted?
Shear Magic
Stage: 3 Challenge Level:
What are the areas of these triangles? What do you notice? Can you generalise to other "families" of triangles?
Jam
Stage: 4 Challenge Level:
A game for 2 players
Nim-interactive
Stage: 3 and 4 Challenge Level:
Start with any number of counters in any number of piles. 2 players take it in turns to remove any number of counters from a single pile. The winner is the player to take the last counter.
Loopy
Stage: 4 Challenge Level:
Investigate sequences given by $a_n = \frac{1+a_{n-1}}{a_{n-2}}$ for different choices of the first two terms. Make a conjecture about the behaviour of these sequences. Can you prove your conjecture?
Lower Bound
Stage: 3 Challenge Level:
What would you get if you continued this sequence of fraction sums? 1/2 + 2/1 = 2/3 + 3/2 = 3/4 + 4/3 =
Picturing Square Numbers
Stage: 3 Challenge Level:
Square numbers can be represented as the sum of consecutive odd numbers. What is the sum of 1 + 3 + ..... + 149 + 151 + 153?
Thank Your Lucky Stars
Stage: 4 Challenge Level:
A counter is placed in the bottom right hand corner of a grid. You toss a coin and move the star according to the following rules: ... What is the probability that you end up in the top left-hand. . . .
Sliding Puzzle
Stage: 1, 2, 3 and 4 Challenge Level:
The aim of the game is to slide the green square from the top right hand corner to the bottom left hand corner in the least number of moves.
One, Three, Five, Seven
Stage: 3 and 4 Challenge Level:
A game for 2 players. Set out 16 counters in rows of 1,3,5 and 7. Players take turns to remove any number of counters from a row. The player left with the last counter looses.
Multiplication Arithmagons
Stage: 4 Challenge Level:
Can you find the values at the vertices when you know the values on the edges of these multiplication arithmagons?
Winning Lines
Stage: 2, 3 and 4
An article for teachers and pupils that encourages you to look at the mathematical properties of similar games.
Attractive Tablecloths
Stage: 4 Challenge Level:
Charlie likes tablecloths that use as many colours as possible, but insists that his tablecloths have some symmetry. Can you work out how many colours he needs for different tablecloth designs?
Pareq Calc
Stage: 4 Challenge Level:
Triangle ABC is an equilateral triangle with three parallel lines going through the vertices. Calculate the length of the sides of the triangle if the perpendicular distances between the parallel. . . .
Chess
Stage: 3 Challenge Level:
What would be the smallest number of moves needed to move a Knight from a chess set from one corner to the opposite corner of a 99 by 99 square board?
Jam
Stage: 4 Challenge Level:
To avoid losing think of another very well known game where the patterns of play are similar.
Intersecting Circles
Stage: 3 Challenge Level:
Three circles have a maximum of six intersections with each other. What is the maximum number of intersections that a hundred circles could have?
Pentanim
Stage: 2, 3 and 4 Challenge Level:
A game for 2 players with similaritlies to NIM. Place one counter on each spot on the games board. Players take it is turns to remove 1 or 2 adjacent counters. The winner picks up the last counter.
Go Forth and Generalise
Stage: 3
Spotting patterns can be an important first step - explaining why it is appropriate to generalise is the next step, and often the most interesting and important.
Tourism
Stage: 3 Challenge Level:
If you can copy a network without lifting your pen off the paper and without drawing any line twice, then it is traversable. Decide which of these diagrams are traversable.
Special Sums and Products
Stage: 3 Challenge Level:
Find some examples of pairs of numbers such that their sum is a factor of their product. eg. 4 + 12 = 16 and 4 × 12 = 48 and 16 is a factor of 48.
Enclosing Squares
Stage: 3 Challenge Level:
Can you find sets of sloping lines that enclose a square?
Stage: 3 Challenge Level:
List any 3 numbers. It is always possible to find a subset of adjacent numbers that add up to a multiple of 3. Can you explain why and prove it?
Hidden Squares
Stage: 3 Challenge Level:
Rectangles are considered different if they vary in size or have different locations. How many different rectangles can be drawn on a chessboard?
Converging Means
Stage: 3 Challenge Level:
Take any two positive numbers. Calculate the arithmetic and geometric means. Repeat the calculations to generate a sequence of arithmetic means and geometric means. Make a note of what happens to the. . . .
Mini-max
Stage: 3 Challenge Level:
Consider all two digit numbers (10, 11, . . . ,99). In writing down all these numbers, which digits occur least often, and which occur most often ? What about three digit numbers, four digit numbers. . . .
Picturing Triangle Numbers
Stage: 3 Challenge Level:
Triangle numbers can be represented by a triangular array of squares. What do you notice about the sum of identical triangle numbers?
Games Related to Nim
Stage: 1, 2, 3 and 4
This article for teachers describes several games, found on the site, all of which have a related structure that can be used to develop the skills of strategic planning.
Sum Equals Product
Stage: 3 Challenge Level:
The sum of the numbers 4 and 1 [1/3] is the same as the product of 4 and 1 [1/3]; that is to say 4 + 1 [1/3] = 4 × 1 [1/3]. What other numbers have the sum equal to the product and can this be so for. . . .
Painted Cube
Stage: 3 Challenge Level:
Imagine a large cube made from small red cubes being dropped into a pot of yellow paint. How many of the small cubes will have yellow paint on their faces?
Nim
Stage: 4 Challenge Level:
Start with any number of counters in any number of piles. 2 players take it in turns to remove any number of counters from a single pile. The loser is the player who takes the last counter.
Mystic Rose
Stage: 3 Challenge Level:
Use the animation to help you work out how many lines are needed to draw mystic roses of different sizes.
Egyptian Fractions
Stage: 3 Challenge Level:
The Egyptians expressed all fractions as the sum of different unit fractions. Here is a chance to explore how they could have written different fractions.
Cuboid Challenge
Stage: 3 Challenge Level:
What size square corners should be cut from a square piece of paper to make a box with the largest possible volume?
Masterclass Ideas: Generalising
Stage: 2 and 3 Challenge Level:
A package contains a set of resources designed to develop pupils’ mathematical thinking. This package places a particular emphasis on “generalising” and is designed to meet the. . . .
Handshakes
Stage: 3 Challenge Level:
Can you find an efficient method to work out how many handshakes there would be if hundreds of people met?
Plus Minus
Stage: 4 Challenge Level:
Can you explain the surprising results Jo found when she calculated the difference between square numbers?
Steps to the Podium
Stage: 2 and 3 Challenge Level:
It starts quite simple but great opportunities for number discoveries and patterns!
Magic Letters
Stage: 3 Challenge Level:
Charlie has made a Magic V. Can you use his example to make some more? And how about Magic Ls, Ns and Ws?
Generating Triples
Stage: 4 Challenge Level:
Sets of integers like 3, 4, 5 are called Pythagorean Triples, because they could be the lengths of the sides of a right-angled triangle. Can you find any more?
Christmas Chocolates
Stage: 3 Challenge Level:
How could Penny, Tom and Matthew work out how many chocolates there are in different sized boxes?
For Richer for Poorer
Stage: 3 Challenge Level:
Charlie has moved between countries and the average income of both has increased. How can this be so?
Partitioning Revisited
Stage: 3 Challenge Level:
We can show that (x + 1)² = x² + 2x + 1 by considering the area of an (x + 1) by (x + 1) square. Show in a similar way that (x + 2)² = x² + 4x + 4
Seven Squares - Group-worthy Task
Stage: 3 Challenge Level:
Choose a couple of the sequences. Try to picture how to make the next, and the next, and the next... Can you describe your reasoning?
Nim-like Games
Stage: 2, 3 and 4 Challenge Level:
A collection of games on the NIM theme
|
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|
http://mathematica.stackexchange.com/questions/30714/why-this-numerical-integration-takes-so-long
|
# Why this numerical integration takes so long?
Let me explain the problem. I am trying to integrate a one dimensional integral: $$\int {g\left( {{k_x}},parameter1,parameter2,...\right)d{\mkern 1mu} {k_x}}$$
for the sake of clarity, I will give function g in the last.
I choose a specific set of parameter, and do the following integration:
In:=NIntegrate[g[kx, 9, -2, 7, 1, 1, 0.05], {kx, -\[Pi]/3,\[Pi]/3}]//AbsoluteTiming
Out:={422.396160, 0.163126 + 0.103155 I}
This takes me 422s on my computer!!!
I use the following code to show the sampling points used during the integration.
sampp = Reap[
NIntegrate[#, {kx, -\[Pi]/(3), \[Pi]/(3)},
EvaluationMonitor :> Sow[{kx, #}]]] &[
g[kx, 9, -2, 7, 1, 1, 0.05]] ;
{Length[#], ListPlot[#, AxesOrigin -> {0, 0}, Filling -> Axis]} &[
relist@sampp[[2, 2, 1]]]
it shows that it used 733 sample points. But should that take 400 seconds?
Actually, the evaluation of the integrand at each sample point is acually fast. I use the most simple interpolation method to do the same integration as below, I use 1000 sample points that is evenly distributed and it only takes 1.3 second. Besides the integration result is quite accurate.
In:=(sampp = Table[{kx,
g[kx, 9, -2, 7, 1, 1, 0.05]}, {kx, -\[Pi]/3, \[Pi]/3,
2 \[Pi]/3/1000}];
Integrate[
Interpolation[sampp, InterpolationOrder -> 2][
x], {x, -\[Pi]/3, \[Pi]/3}]) // AbsoluteTiming
Out:={1.308075, 0.163126 + 0.103155 I}
So what did Mathematica do in the extremely long 400 second? Of course, it needs to do many error estimation, but that should not take too much time.
I scan the documents and related questions in stackexchange. Somebody suggest to set "SymbolicProcessing"->0. OK, I tried
In:=NIntegrate[g[kx, 9, -2, 7, 1, 1, 0.05], {kx, -\[Pi]/3, \[Pi]/3},
Method -> {"GlobalAdaptive", Method -> "GaussKronrodRule",
"SymbolicProcessing" -> 0}]//AbsoluteTiming
Out:={401.791981, 0.163126 + 0.103155 I}
unfortunately, the result is the same.
Even more peculiar, when I use "Trapezoidal" strategy and limit the MaxRecursion
In:=NIntegrate[g[kx, 9, -2, 7, 1, 1, 0.05], {kx, -\[Pi]/3, \[Pi]/3},
Method -> "Trapezoidal", MinRecursion -> 1, MaxRecursion -> 4]
Out:={413.894674, 0.163126 + 0.103155 I}
the sample points shows as follows it only used 257 sample point, but the time cost is the same??!!It is unbelievable! Anyway, I think the "Trapezoidal" should be the same as evenly sample interpolation method.
I really can't understand what did Mathematica do in the NIntegrate of function g. Can somebody explain it?
Of course, it seems that I can use the simple interpolation integration method manually, because it is fast, and the result seems good in this case. But it is not robust, I insisted using the built in "Adaptive" strategy, because I have to Integrate some other functions which are sharp at specific points.
In the last the form of function g
g[kx_, xx_, e_, width_, ii_, label_, \[Eta]_] :=
Inverse[(e - I \[Eta]) IdentityMatrix[2*width] -
armchairibbonmat[kx, width]][[2*(ii - 1) + label,
2*(ii - 1) + label]] E^(I kx xx)
(*armchairibbonmat is a function used in function g*)
armchairibbonmat[kx_, n_] :=
(
h = Table[0, {i, 1, 2 (n + 2)}, {j, 1, 2 (n + 2)}];
a[m_] := 2 m - 1;
b[m_] := 2 m;
t1 = 1;
aa = 1;
Do[
h[[b[i], a[i]]] = t1 E^(I kx aa);
h[[a[i], b[i]]] = t1 E^(-I kx aa);
h[[b[i + 1], a[i]]] = t1 E^(-I kx aa/2);
h[[b[i - 1], a[i]]] = t1 E^(-I kx aa/2);
h[[a[i - 1], b[i]]] = t1 E^(I kx aa/2);
h[[a[i + 1], b[i]]] = t1 E^(I kx aa/2);
, {i, 2, n + 1}];
)
-
Sorry, everyone, I made a few typoerrors in the definition of function g at first, but now it is fixed. thank you. – matheorem Aug 19 '13 at 8:26
If you replace
g[kx_,
with
g[kx_?NumericQ
Things will work as you expect.
Update: Evaluation of
g[kx, 9, -2, 7, 1, 1, 0.05]
takes a long time and the _?NumericQ absolutely prevents the symbolic evaluation.
-
I like short answers that get to the point! – Yves Klett Aug 19 '13 at 9:24
@ruebenko it works!! Thank you!! If I would know the answer is so simple, I would not have written such a long detailed question, HaHa – matheorem Aug 19 '13 at 9:59
@ruebenko But why this fixed the problem? Can you explain a little? – matheorem Aug 19 '13 at 10:01
See update, there many similar examples in this forum, have a look. – user21 Aug 19 '13 at 10:36
@ruebenko but why "SymbolicProcessing" -> 0 didn't work? – matheorem Aug 23 '13 at 9:20
|
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|
https://jayryablon.wordpress.com/2008/05/01/heisenberg-and-schwinger-continued-draft-paper/
|
# Lab Notes for a Scientific Revolution (Physics)
## May 1, 2008
### Heisenberg Uncertainty and Schwinger Anomaly Continued: Draft Paper
I have been writing a paper to rigorously develop the hypothesis I presented last week, in a post linked at Heisenberg Uncertainty and Schwinger Anomaly: Two Sides of the Same Coin?. I believe there is enough developed now, and I think enough of the kinks are now out, so you all may take a sneak preview. Thus, I have linked my latest draft at:
Heisenberg Uncertainty and the Schwinger Anomaly
Setting aside the hypothesized connection between the magnetic anomaly and uncertainty, Sections 4 through 7, which have not been posted in any form previously, stand completely by themselves, irrespective of this hypothesis. These sections are strictly mathematical in nature, and they provide an exact measure for how the uncertainty associated with a wavefunction varies upwards from $\hbar/2$ as a function of the potential, and the parameters of the wavefunction itself. The wavefunction employed is completely general, and the uncertainty relation is driven by a potential $V$.
This is still under development, but this should give you a very good idea of where this is headed.
Of course, I welcome comment, as always.
Best regards,
Jay.
## 1 Comment »
1. Good post. I learn something new and challenging on blogs I stumbleupon everyday.
It will always be interesting to read through content from other authors
and practice a little something from their
websites.
A blog page regarding technological innovation: 5.1 surround system – Danuta,
Comment by Danuta — August 27, 2013 @ 8:29 am
Create a free website or blog at WordPress.com.
|
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|
https://socratic.org/questions/how-do-you-simplify-4-98-0
|
Algebra
Topics
# How do you simplify 4.98^0?
Jan 20, 2017
${4.98}^{0} = \textcolor{g r e e n}{1}$
#### Explanation:
Any number (excluding perhaps zero) to the power of $0$ is equal to $1$
Consider the following sequence for any number $n$ which is not zero:
$\textcolor{w h i t e}{\text{XXX}} {n}^{4} = n \times n \times n \times n$
$\textcolor{w h i t e}{\text{XXX}} {n}^{3} = \frac{{n}^{4}}{n} = n \times n \times n$
$\textcolor{w h i t e}{\text{XXX}} {n}^{2} = \frac{{n}^{3}}{n} = n \times n$
$\textcolor{w h i t e}{\text{XXX}} {n}^{1} = \frac{{n}^{2}}{n} = n$
$\textcolor{w h i t e}{\text{XXX}} {n}^{0} = \frac{{n}^{1}}{n} = \frac{n}{n} = 1$
...and we could continue on:
$\textcolor{w h i t e}{\text{XXX}} {n}^{- 1} = \frac{{n}^{0}}{n} = \frac{1}{n}$
$\textcolor{w h i t e}{\text{XXX}} {n}^{- 2} = \frac{{n}^{- 1}}{n} = \frac{1}{{n}^{2}}$
$\textcolor{w h i t e}{\text{XXX}} {n}^{- 3} = \frac{{n}^{- 2}}{n} = \frac{1}{{n}^{3}}$
...and so on...
Jan 20, 2017
Another way of writing ${4.98}^{0}$ is : $\frac{4.98}{4.98} = 1$
|
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|
http://mathhelpforum.com/calculus/63223-show-volume-pyramid-height-h-whose-base-equilateral-triangle-o.html
|
# Math Help - Show that the volume of a pyramid of height h whose base is an equilateral triangle o
1. ## Show that the volume of a pyramid of height h whose base is an equilateral triangle o
Show that the volume of a pyramid of height h whose base is an equilateral triangle of side s is equal to
{(√3)(h)(s^2)}
(12)
2. Originally Posted by derrickd
Show that the volume of a pyramid of height h whose base is an equilateral triangle of side s is equal to
{(√3)(h)(s^2)}
(12)
For, equilateral triangle of base,
height of equilateral triangle $= \sqrt{s^2-\left(\frac{s}{2}\right)^2}=\frac{s\sqrt{3}}{2}$
Area of equilateral triangle (base) $A= \frac{s\times \frac{s\sqrt{3}}{2}}{2}=\frac{s^2\sqrt{3}}{4}$
Volume= $\frac{A\times h}{3}=\frac{\frac{s^2\sqrt{3}}{4}h}{3}=\frac{hs^2\ sqrt{3}}{12}$
|
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|
https://math.stackexchange.com/questions/3393578/cubic-polynomial-smoothly-connecting-two-circles
|
# Cubic polynomial smoothly connecting two circles
Given two circles with radii $$R_L$$ and $$R_R$$ and centers at $$(-(R_L+a),\,0)$$ and $$(R_R+a,\,0)$$, respectively, find a cubic polynomial $$p(x)=b+cx^2+dx^3$$ that smoothly connects the two circles.
$$b$$ is a parameter so $$p(0)=b$$ and the linear term of the polynomial is omitted because we want $$\frac{\mathrm{d}p}{\mathrm{d}x}\Big|_{x=0}=0$$.
My attempt at a solution. Let $$\mathrm{C}_{L,R}$$ the equations for the upper half of the $$L,R$$ circles. I formulate two equations relating $$\mathrm{C}_{L,R}$$ and $$p$$, and two equations relating $$\frac{\mathrm{d}}{\mathrm{d}x}\mathrm{C}_{L,R}$$ and $$\frac{\mathrm{d}p}{\mathrm{d}x}$$. Let $$x_{L,R}$$ be the points where $$p(x)$$ and $$\mathrm{C}_{L,R}(x)$$ intersect, then:
$$\mathrm{C}_L(x_L)-p(x_L) = 0$$ $$\mathrm{C}_R(x_R)-p(x_R) = 0$$ $$\frac{\mathrm{d}}{\mathrm{d}x}\mathrm{C}_L(x_L) - \frac{\mathrm{d}p}{\mathrm{d}x}(x_L) = 0$$ $$\frac{\mathrm{d}}{\mathrm{d}x}\mathrm{C}_R(x_R) - \frac{\mathrm{d}p}{\mathrm{d}x}(x_R) = 0$$ so I have a system of four nonlinear equations with four unknowns $$(x_L,\,x_R,\,c,\,d)$$. I coded a simple Newton's method for the system and it works well for some combinations of parameters $$(a,\,b,\,R_L,\,R_R)$$ when the initial guess is close enough, especially when $$|R_L-R_R|$$ is not too large and I use a constant damping for the Newton iterations. I can find initial guesses that I think are good via a graphical interface I coded. However, as $$|R_L-R_R|$$ gets larger the solver fails spectacularly to converge even with very close initial guesses and very small damping. (I should add that I'm actually taking the square of the equations to avoid square roots of negative numbers during the Newton iterations).
My question is threefold:
a) what other method or modification can I use to make the solver more stable?
b) this problem seems to me like it should be solved somewhere, do you know a reference?
c) more generally, is there a reason this should fail as horribly as it does when $$|R_L-R_R|>>1$$?
• I would try parametrizing this with only two unknowns $x_{L,R}$, fitting a cubic polynomial $a_0+a_1x+a_2x^2+a_3x^3$ to the points and tangents on the circles, and solving for $a_0=b,a_1=0$ instead. – user856 Oct 14 '19 at 16:48
• Thank you. I'm not sure I follow. If I did that, wouldn't $a_2$ and $a_3$ be unknowns as well? If I had two unknowns and four equations I'm not even sure what I could do. Also, setting $a_0=b$ and $a_1=0$ is exactly what I'm doing. By fitting do you mean I should try some optimisation technique? – mvaldez Oct 14 '19 at 17:03
• Do you mean that parameter $b$ si fixed : all curves must pass through point $(0,b)$ ? – Jean Marie Oct 14 '19 at 17:05
• yes, the parameters $(a,\,b,\,R_L,\,R_R)$ are fixed so the curve I want to find must pass through $(0,\,b)$ and have vanishing derivative there – mvaldez Oct 14 '19 at 17:07
• I mean treat only the points $x_{L,R}$ as unknowns. Compute a cubic polynomial $a_0+a_1x+a_2x^2+a_3x^3$ passing through them, which can be done in closed form. Then you get $c=a_2,d=a_3$. But you may not have $a_0=b,a_1=0$, so you need to choose $x_{L,R}$ to satisfy them. Thus you have two nonlinear equations in two unknowns. – user856 Oct 14 '19 at 17:09
Here is a method giving all solutions in a deterministic way.
Take a look at the following figure :
Fig. 1 : The exhaustive set of 8 solution curves in the case $$a=1, \ b=1, \ R_L=3, \ R_R=1$$. Please note that some tangencies are internal to the circles.
How has this result been obtained ? By using a Computer Algebra System with a rather simple system of 4 polynomial equations in the 4 unknowns $$c,d,x_L,x_R$$ where (your notations) the two last parameters are the abscissas of the tangency points of the cubic curve with equation
$$y=f(x)=b+cx^2+dx^3$$
with the Left and Right circle resp.
Here they are:
$$\begin{cases}(x_L+R_L+a)^2+f(x_L)^2&=&R_L^2& \ \ (i)\\ (x_R-R_R-a)^2+f(x_R)^2&=&R_R^2& \ \ (ii)\\ \dfrac{f(x_L)}{x_L+R_L+a}&=&- \dfrac{1}{f'(x_L)}& \ \ (iii)\\ \dfrac{f(x_R)}{x_R-R_R-a}&=&- \dfrac{1}{f'(x_R)}& \ \ (iv)\\ \end{cases}\tag{1}$$
The first two equations express that $$M_L=(x_L,f(x_L))$$ and $$M_R=(x_R,f(x_R))$$ belong to their resp. circles.
Let us now explain the third equation. Let $$C_L(-(R_L+a),0)$$ denotes the center of the first circle. The slope of the tangent in $$M_L$$ is $$f'(x_L)$$. $$\vec{C_LM_L}=\binom{x_L+R_L+a}{f(x_L)-0}$$, being orthogonal to this tangent, has a slope $$-\dfrac{1}{f'(x_L)}$$ (see there). Similar reasoning for the fourth equation.
Remarks :
1) I haven't found the limitations you mention in the case of a large gap between $$R_L$$ and $$R_R$$. For example when $$R_L=100$$ and $$R_R=1$$, (with $$a=1$$ and $$b=0$$), one finds 14 solutions...
2) The third equation can be written : $$f(x_L)f'(x_L)+x_L+R_L+a=0$$ : this avoids possible division by zero. Same thing for the fourth equation.
Another case (Fig. 2), this time with $$R_L=R_R$$ displaying some spurious solutions under the form of ... second degree curves, i.e., parabolas (one can indeed have $$d=0$$) :
Fig. 2.
Still another case, with four solutions (one of them looks to be a parabola but isn't):
Fig. 3.
Here is the Matlab program that has given figure 1
(running time : around 30 seconds on my rather slow computer). Please note the "isreal" conditions (we want the different unknowns to be real) : in fact in the first case, there are $$40$$ solutions, $$32$$ of them being spurious, i.e., with complex coefficients...
Final remark : In fact, there exists a different way to solve system (1) by doing it in two steps ; first, by expressing the fact that equations (i) and (iii) have a common root $$x_L$$ giving (using a "resultant" ) a first (non-linear) constraint between $$c$$ and $$d$$. Doing the same for equations (ii) and (iv) for common root $$x_R$$, gives a second constraint. Then, in a second step, solve the system of 2 (non-linear...) equations in 2 unknowns $$c$$ and $$d$$.
syms xL xR c d;%symbolic variables declaration
a=1;b=1;m=max([RL,RR]);p=2*m+a;
axis([-p+3,p+3,-p-3,p+3]);axis equal;
f=@(x)(b+c*x*x+d*x*x*x);%cubic function
fp=@(x)(2*c*x+3*d*x*x);%its derivative
%The system of 4 equations in 4 unknowns ; sol. in [XL,XR,C,D]
[XL,XR,C,D]=solve(...
(xL+RL+a)^2+f(xL)^2==RL^2,
(xR-RR-a)^2+f(xR)^2==RR^2,...
xL+f(xL)*fp(xL)==-RL-a,...
xR+f(xR)*fp(xR)==RR+a,...
xL,xR,c,d);% the 4 variables
plot([-p,p],[0,0]);\$x axis
plot([0,0],[-p,p]);%y axis
UC=exp(i*(0:0.01:2*pi));%unit circle
plot(-(RL+a)+RL*UC,'k');%circle C_L
plot((RR+a)+RR*UC,'k');%circle C_R
x=-p:0.01:p;%range of values for x
for k=1:length(XL)
c=C(k);d=D(k);xL=XL(k);xR=XR(k);
if isreal(c) && isreal(d) && isreal(xL) && isreal(xR)
plot(x,b+c*x.*x+d*x.*x.*x,'color',rand(1,3));hold on;
end;
end;
• Thank you Jean Marie, your answer was very helpful. This new set of equations seem to be much more stable – mvaldez Oct 22 '19 at 20:45
• Thanks. I have added a small remark (remark 2). – Jean Marie Oct 23 '19 at 7:06
• See as well the final remark I just added. – Jean Marie Oct 23 '19 at 7:42
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http://mathoverflow.net/questions/134417/two-variable-polynomials-irreducible-as-formal-power-series
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# Two-variable polynomials, irreducible as formal power series
Let $k$ be a field and $f\in k[a,b]$ an irreducible two-variable polynomial, $B := k[a,b]/(f)$ and $C$ the integral closure of $B$ in its fraction field.
I call $f$ good if it is irreducible in the ring $k[[a,b]]$ of formal power series; equivalently (Nagata, Local Rings, p. 122, Ex. 1), if $C$ has exactly one prime ideal lying above $\mathfrak m = (a,b)B$ (hence, $f$ being good just means that the curve $B$ is analytically irreducible at the origin).
I'm looking for examples of "good" polynomials $f$ such that the residue field $L$ of $C$ is a proper extension of $k$.
I can show (at least if $k$ is infinite) that $[L:k] \cdot r = \mu(f)$, where $\mu(f)$ is the degree of the lowest-degree summand of $f$, and $r$ is the ramification index of $\mathfrak m$ in $C$. Hence, it is clear that $\mu(f)$ must be large enough if one wants interesting examples.
The only "generic" class of examples I could come up with is the one where $f$ is homogeneous: Then $f$ being irreducible implies $f$ is good, and $[L:k] = \deg f$.
-
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|
https://www.physicsforums.com/threads/riesz-lemma.114238/
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# Riesz Lemma
1. Mar 14, 2006
### Castilla
Good Morning.
I am reading the first pages of the "Lessons of Functional Analysis" of Riesz and Nagy, because I learned that this book was the main source for Apostol chapter about the Lebesgue Integral, and I am trying to find a proof of the Fundamental Theorem of Calculus for Lebesgue Integrals worked out within this approach (not Measure Theory).
One of the first theorems of Riesz-Nagy's book states: "Every monotonic function f(x) posseses a finite derivative at every point x with the possible exception of the points x of a set of measure zero".
To proof this T they use this lemma:
"Let g(x) be a continuous function defined in the closed interval (a, b), and let E be the set of points x interior to this interval and such that there exists and e lying to the right of x with g(e) > g(x). Then the set E is either empty or an open set, i.e., it decomposes into a finite number or a denumerable infinity of open and disjoint intervals (a_k, b_k) (the underline is mine), and g(a_k) < g(b_k) for all these intervals".
Well I suppose I can follow the lemma's proof on the book but in this
statement there is something I did not know. Why to be E an opet set implies that it decomposes into a finite number or a denumerable infinity of open and disjoint intervals ???
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|
https://hwdong.net/2018/05/10/LogisticRegression_with_a_Neural_Network/
|
# "Logistic Regression with a Neural Network mindset"
## "Logistic Regression with a Neural Network mindset"
Posted by xuepro on May 10, 2018
# Logistic Regression with a Neural Network mindset
You will learn to:
• Build the general architecture of a learning algorithm, including:
• Initializing parameters
• Calculating the cost function and its gradient
• Using an optimization algorithm (gradient descent)
• Gather all three functions above into a main model function, in the right order.
## 1 - Packages
First, let’s run the cell below to import all the packages that you will need during this assignment.
• numpy is the fundamental package for scientific computing with Python.
• h5py is a common package to interact with a dataset that is stored on an H5 file.
• matplotlib is a famous library to plot graphs in Python.
• PIL and scipy are used here to test your model with your own picture at the end.
import numpy as np
import matplotlib.pyplot as plt
import h5py
import scipy
from PIL import Image
from scipy import ndimage
%matplotlib inline
## 2 - Overview of the Problem set
Problem Statement: You are given a dataset (“data.h5”) containing:
• a training set of m_train images labeled as cat (y=1) or non-cat (y=0)
• a test set of m_test images labeled as cat or non-cat
• each image is of shape (num_px, num_px, 3) where 3 is for the 3 channels (RGB). Thus, each image is square (height = num_px) and (width = num_px).
You will build a simple image-recognition algorithm that can correctly classify pictures as cat or non-cat.
Let’s get more familiar with the dataset. Load the data by running the following code.
# you should make a dir called 'datasets' in your current directory在当前路径下建一个文件夹 datasets
import urllib.request
import zipfile
url_utils = 'https://raw.githubusercontent.com/andersy005/deep-learning-specialization-coursera/master/01-Neural-Networks-and-Deep-Learning/week2/Programming-Assignments/lr_utils.py'
urllib.request.urlretrieve(url_utils, 'lr_utils.py')
url_trainSet = 'https://github.com/andersy005/deep-learning-specialization-coursera/raw/master/01-Neural-Networks-and-Deep-Learning/week2/Programming-Assignments/datasets/train_catvnoncat.h5'
urllib.request.urlretrieve(url_trainSet, 'datasets/train_catvnoncat.h5')
url_testSet = 'https://github.com/andersy005/deep-learning-specialization-coursera/raw/master/01-Neural-Networks-and-Deep-Learning/week2/Programming-Assignments/datasets/test_catvnoncat.h5'
urllib.request.urlretrieve(url_testSet, 'datasets/test_catvnoncat.h5')
'''
url_data = 'https://github.com/andersy005/deep-learning-specialization-coursera/raw/master/01-Neural-Networks-and-Deep-Learning/week2/Programming-Assignments/datasets.zip'
data = urllib.request.urlopen(url_data)
with open("datasets.zip", "wb") as code:
code.write(dataset)
# unzip datasets
with zipfile.ZipFile("datasets.zip","r") as zip_ref:
zip_ref.extractall("")
'''
downloading with urllib...please wait...
# Loading the data (cat/non-cat)
train_set_x_orig, train_set_y, test_set_x_orig, test_set_y, classes = load_dataset()
# Example of a picture
index = 27
plt.imshow(train_set_x_orig[index])
print ("y = " + str(train_set_y[:, index]) + ", it's a '" + classes[np.squeeze(train_set_y[:, index])].decode("utf-8") + "' picture.")
y = [1], it's a 'cat' picture.
### START CODE HERE ### (≈ 3 lines of code)
m_train = train_set_x_orig.shape[0]
m_test = test_set_x_orig.shape[0]
num_px = train_set_x_orig.shape[1]
### END CODE HERE ###
print ("Number of training examples: m_train = " + str(m_train))
print ("Number of testing examples: m_test = " + str(m_test))
print ("Height/Width of each image: num_px = " + str(num_px))
print ("Each image is of size: (" + str(num_px) + ", " + str(num_px) + ", 3)")
print ("train_set_x shape: " + str(train_set_x_orig.shape))
print ("train_set_y shape: " + str(train_set_y.shape))
print ("test_set_x shape: " + str(test_set_x_orig.shape))
print ("test_set_y shape: " + str(test_set_y.shape))
Number of training examples: m_train = 209
Number of testing examples: m_test = 50
Height/Width of each image: num_px = 64
Each image is of size: (64, 64, 3)
train_set_x shape: (209, 64, 64, 3)
train_set_y shape: (1, 209)
test_set_x shape: (50, 64, 64, 3)
test_set_y shape: (1, 50)
# Reshape the training and test examples
### START CODE HERE ### (≈ 2 lines of code)
train_set_x_flatten = train_set_x_orig.reshape(train_set_x_orig.shape[0],-1).T
test_set_x_flatten = test_set_x_orig.reshape(test_set_x_orig.shape[0],-1).T
### END CODE HERE ###
print ("train_set_x_flatten shape: " + str(train_set_x_flatten.shape))
print ("train_set_y shape: " + str(train_set_y.shape))
print ("test_set_x_flatten shape: " + str(test_set_x_flatten.shape))
print ("test_set_y shape: " + str(test_set_y.shape))
print ("sanity check after reshaping: " + str(train_set_x_flatten[0:5,0]))
train_set_x_flatten shape: (12288, 209)
train_set_y shape: (1, 209)
test_set_x_flatten shape: (12288, 50)
test_set_y shape: (1, 50)
sanity check after reshaping: [17 31 56 22 33]
Let’s standardize our dataset.
train_set_x = train_set_x_flatten/255.
test_set_x = test_set_x_flatten/255.
Common steps for pre-processing a new dataset are:
• Figure out the dimensions and shapes of the problem (m_train, m_test, num_px, …)
• Reshape the datasets such that each example is now a vector of size (num_px * num_px * 3, 1)
• “Standardize” the data
## 3 - General Architecture of the learning algorithm
You will build a Logistic Regression, using a Neural Network mindset. The following Figure explains why Logistic Regression is actually a very simple Neural Network!
For one example $$x^{(i)}$$:
$z^{(i)} = w^T x^{(i)} + b \tag{1}$ $\hat{y}^{(i)} = a^{(i)} = sigmoid(z^{(i)})\tag{2}$ $\mathcal{L}(a^{(i)}, y^{(i)}) = - y^{(i)} \log(a^{(i)}) - (1-y^{(i)} ) \log(1-a^{(i)})\tag{3}$
The cost is then computed by summing over all training examples:
$J = \frac{1}{m} \sum_{i=1}^m \mathcal{L}(a^{(i)}, y^{(i)})\tag{6}$
• Initialize the parameters of the model
• Learn the parameters for the model by minimizing the cost
• Use the learned parameters to make predictions (on the test set)
• Analyse the results and conclude
## 4 - Building the parts of our algorithm
• Define the model structure (such as number of input features)
• Initialize the model’s parameters
• Loop:
• Calculate current loss (forward propagation)
• Calculate current gradient (backward propagation)
### 4.1 - Helper functions
# GRADED FUNCTION: sigmoid
def sigmoid(z):
"""
Compute the sigmoid of z
Arguments:
z -- A scalar or numpy array of any size.
Return:
s -- sigmoid(z)
"""
### START CODE HERE ### (≈ 1 line of code)
s = 1 / (1 + np.exp(-z))
### END CODE HERE ###
return s
print ("sigmoid([0, 2]) = " + str(sigmoid(np.array([0,2]))))
sigmoid([0, 2]) = [0.5 0.88079708]
### 4.2 - Initializing parameters
# GRADED FUNCTION: initialize_with_zeros
def initialize_with_zeros(dim):
"""
This function creates a vector of zeros of shape (dim, 1) for w and initializes b to 0.
Argument:
dim -- size of the w vector we want (or number of parameters in this case)
Returns:
w -- initialized vector of shape (dim, 1)
b -- initialized scalar (corresponds to the bias)
"""
### START CODE HERE ### (≈ 1 line of code)
w = np.zeros([dim,1])
b = 0
### END CODE HERE ###
assert(w.shape == (dim, 1))
assert(isinstance(b, float) or isinstance(b, int))
return w, b
dim = 2
w, b = initialize_with_zeros(dim)
print ("w = " + str(w))
print ("b = " + str(b))
w = [[0.]
[0.]]
b = 0
### 4.3 - Forward and Backward propagation
#### Forward Propagation:
• You get X
• You compute $$A = \sigma(w^T X + b) = (a^{(0)}, a^{(1)}, ..., a^{(m-1)}, a^{(m)})$$
• You calculate the cost function: $$J = -\frac{1}{m}\sum_{i=1}^{m}y^{(i)}\log(a^{(i)})+(1-y^{(i)})\log(1-a^{(i)})$$
Here are the two formulas you will be using:
# GRADED FUNCTION: propagate
def propagate(w, b, X, Y):
"""
Implement the cost function and its gradient for the propagation explained above
Arguments:
w -- weights, a numpy array of size (num_px * num_px * 3, 1)
b -- bias, a scalar
X -- data of size (num_px * num_px * 3, number of examples)
Y -- true "label" vector (containing 0 if non-cat, 1 if cat) of size (1, number of examples)
Return:
cost -- negative log-likelihood cost for logistic regression
dw -- gradient of the loss with respect to w, thus same shape as w
db -- gradient of the loss with respect to b, thus same shape as b
Tips:
- Write your code step by step for the propagation. np.log(), np.dot()
"""
m = X.shape[1]
# FORWARD PROPAGATION (FROM X TO COST)
### START CODE HERE ### (≈ 2 lines of code)
A = sigmoid(np.dot(w.T,X) + b) # compute activation
cost = -1/m * (np.dot(Y,np.log(A).T) + np.dot((1-Y),np.log(1 - A).T)) # compute cost
### END CODE HERE ###
# BACKWARD PROPAGATION (TO FIND GRAD)
### START CODE HERE ### (≈ 2 lines of code)
dw = 1 / m *(np.dot(X,(A - Y).T))
db = 1 / m *(np.sum(A - Y))
### END CODE HERE ###
assert(dw.shape == w.shape)
assert(db.dtype == float)
cost = np.squeeze(cost)
assert(cost.shape == ())
"db": db}
w, b, X, Y = np.array([[1],[2]]), 2, np.array([[1,2],[3,4]]), np.array([[1,0]])
grads, cost = propagate(w, b, X, Y)
print ("dw = " + str(grads["dw"]))
print ("db = " + str(grads["db"]))
print ("cost = " + str(cost))
dw = [[0.99993216]
[1.99980262]]
db = 0.49993523062470574
cost = 6.000064773192205
#### Optimization
• You have initialized your parameters.
• You are also able to compute a cost function and its gradient.
• Now, you want to update the parameters using gradient descent.
Exercise: Write down the optimization function. The goal is to learn $w$ and $b$ by minimizing the cost function $J$. For a parameter $\theta$, the update rule is $\theta = \theta - \alpha \text{ } d\theta$, where $\alpha$ is the learning rate.
# GRADED FUNCTION: optimize
def optimize(w, b, X, Y, num_iterations, learning_rate, print_cost = False):
"""
This function optimizes w and b by running a gradient descent algorithm
Arguments:
w -- weights, a numpy array of size (num_px * num_px * 3, 1)
b -- bias, a scalar
X -- data of shape (num_px * num_px * 3, number of examples)
Y -- true "label" vector (containing 0 if non-cat, 1 if cat), of shape (1, number of examples)
num_iterations -- number of iterations of the optimization loop
learning_rate -- learning rate of the gradient descent update rule
print_cost -- True to print the loss every 100 steps
Returns:
params -- dictionary containing the weights w and bias b
grads -- dictionary containing the gradients of the weights and bias with respect to the cost function
costs -- list of all the costs computed during the optimization, this will be used to plot the learning curve.
Tips:
You basically need to write down two steps and iterate through them:
1) Calculate the cost and the gradient for the current parameters. Use propagate().
2) Update the parameters using gradient descent rule for w and b.
"""
costs = []
for i in range(num_iterations):
# Cost and gradient calculation (≈ 1-4 lines of code)
### START CODE HERE ###
### END CODE HERE ###
# update rule (≈ 2 lines of code)
### START CODE HERE ###
w = w - learning_rate*dw
b = b - learning_rate*db
### END CODE HERE ###
# Record the costs
if i % 100 == 0:
costs.append(cost)
# Print the cost every 100 training examples
if print_cost and i % 100 == 0:
print ("Cost after iteration %i: %f" %(i, cost))
params = {"w": w,
"b": b}
"db": db}
params, grads, costs = optimize(w, b, X, Y, num_iterations= 100, learning_rate = 0.009, print_cost = False)
print ("w = " + str(params["w"]))
print ("b = " + str(params["b"]))
print ("dw = " + str(grads["dw"]))
print ("db = " + str(grads["db"]))
w = [[0.1124579 ]
[0.23106775]]
b = 1.5593049248448891
dw = [[0.90158428]
[1.76250842]]
db = 0.4304620716786828
Exercise: The previous function will output the learned w and b. We are able to use w and b to predict the labels for a dataset X. Implement the predict() function. There is two steps to computing predictions:
Calculate $$\hat{Y} = A = \sigma(w^T X + b)$$
Convert the entries of a into 0 (if activation <= 0.5) or 1 (if activation > 0.5), stores the predictions in a vector Y_prediction. If you wish, you can use an if/else statement in a for loop (though there is also a way to vectorize this).
# GRADED FUNCTION: predict
def predict(w, b, X):
'''
Predict whether the label is 0 or 1 using learned logistic regression parameters (w, b)
Arguments:
w -- weights, a numpy array of size (num_px * num_px * 3, 1)
b -- bias, a scalar
X -- data of size (num_px * num_px * 3, number of examples)
Returns:
Y_prediction -- a numpy array (vector) containing all predictions (0/1) for the examples in X
'''
m = X.shape[1]
Y_prediction = np.zeros((1,m))
w = w.reshape(X.shape[0], 1)
# Compute vector "A" predicting the probabilities of a cat being present in the picture
### START CODE HERE ### (≈ 1 line of code)
A = sigmoid(np.dot(w.T,X) + b)
### END CODE HERE ###
for i in range(A.shape[1]):
# Convert probabilities A[0,i] to actual predictions p[0,i]
### START CODE HERE ### (≈ 4 lines of code)
if(A[0][i] <= 0.5):
Y_prediction[0][i] = 0
else:
Y_prediction[0][i] = 1
### END CODE HERE ###
assert(Y_prediction.shape == (1, m))
return Y_prediction
print ("predictions = " + str(predict(w, b, X)))
predictions = [[1. 1.]]
## 5 - Merge all functions into a model
ou will now see how the overall model is structured by putting together all the building blocks (functions implemented in the previous parts) together, in the right order.
Exercise: Implement the model function. Use the following notation:
• Y_prediction for your predictions on the test set
• Y_prediction_train for your predictions on the train set
• w, costs, grads for the outputs of optimize()
# GRADED FUNCTION: model
def model(X_train, Y_train, X_test, Y_test, num_iterations = 2000, learning_rate = 0.5, print_cost = False):
"""
Builds the logistic regression model by calling the function you've implemented previously
Arguments:
X_train -- training set represented by a numpy array of shape (num_px * num_px * 3, m_train)
Y_train -- training labels represented by a numpy array (vector) of shape (1, m_train)
X_test -- test set represented by a numpy array of shape (num_px * num_px * 3, m_test)
Y_test -- test labels represented by a numpy array (vector) of shape (1, m_test)
num_iterations -- hyperparameter representing the number of iterations to optimize the parameters
learning_rate -- hyperparameter representing the learning rate used in the update rule of optimize()
print_cost -- Set to true to print the cost every 100 iterations
Returns:
d -- dictionary containing information about the model.
"""
### START CODE HERE ###
# initialize parameters with zeros (≈ 1 line of code)
w, b = initialize_with_zeros(X_train.shape[0])
# Gradient descent (≈ 1 line of code)
parameters, grads, costs = optimize(w, b, X_train, Y_train, num_iterations, learning_rate, print_cost)
# Retrieve parameters w and b from dictionary "parameters"
w = parameters["w"]
b = parameters["b"]
# Predict test/train set examples (≈ 2 lines of code)
Y_prediction_test = predict(w, b, X_test)
Y_prediction_train = predict(w, b, X_train)
### END CODE HERE ###
# Print train/test Errors
print("train accuracy: {} %".format(100 - np.mean(np.abs(Y_prediction_train - Y_train)) * 100))
print("test accuracy: {} %".format(100 - np.mean(np.abs(Y_prediction_test - Y_test)) * 100))
d = {"costs": costs,
"Y_prediction_test": Y_prediction_test,
"Y_prediction_train" : Y_prediction_train,
"w" : w,
"b" : b,
"learning_rate" : learning_rate,
"num_iterations": num_iterations}
return d
Run the following cell to train your model.
d = model(train_set_x, train_set_y, test_set_x, test_set_y, num_iterations = 2000, learning_rate = 0.005, print_cost = True)
Cost after iteration 0: 0.693147
Cost after iteration 100: 0.584508
Cost after iteration 200: 0.466949
Cost after iteration 300: 0.376007
Cost after iteration 400: 0.331463
Cost after iteration 500: 0.303273
Cost after iteration 600: 0.279880
Cost after iteration 700: 0.260042
Cost after iteration 800: 0.242941
Cost after iteration 900: 0.228004
Cost after iteration 1000: 0.214820
Cost after iteration 1100: 0.203078
Cost after iteration 1200: 0.192544
Cost after iteration 1300: 0.183033
Cost after iteration 1400: 0.174399
Cost after iteration 1500: 0.166521
Cost after iteration 1600: 0.159305
Cost after iteration 1700: 0.152667
Cost after iteration 1800: 0.146542
Cost after iteration 1900: 0.140872
train accuracy: 99.04306220095694 %
test accuracy: 70.0 %
Expected Output:
Train Accuracy 99.04306220095694 % Test Accuracy 70.0 % Comment: Training accuracy is close to 100%. This is a good sanity check: your model is working and has high enough capacity to fit the training data. Test error is 68%. It is actually not bad for this simple model, given the small dataset we used and that logistic regression is a linear classifier. But no worries, you’ll build an even better classifier next week!
Also, you see that the model is clearly overfitting the training data. Later in this specialization you will learn how to reduce overfitting, for example by using regularization. Using the code below (and changing the index variable) you can look at predictions on pictures of the test set.
# Example of a picture that was wrongly classified.
for index in range(20):
#index =
plt.imshow(test_set_x[:,index].reshape((num_px, num_px, 3)))
plt.imshow(test_set_x[:,index+1].reshape((num_px, num_px, 3)))
print ("y = " + str(test_set_y[0,index]) + ", you predicted that it is a \"" + classes[int(d["Y_prediction_test"][0,index])].decode("utf-8") + "\" picture.")
y = 1, you predicted that it is a "cat" picture.
y = 1, you predicted that it is a "cat" picture.
y = 1, you predicted that it is a "cat" picture.
y = 1, you predicted that it is a "cat" picture.
y = 1, you predicted that it is a "cat" picture.
y = 0, you predicted that it is a "cat" picture.
y = 1, you predicted that it is a "non-cat" picture.
y = 1, you predicted that it is a "cat" picture.
y = 1, you predicted that it is a "cat" picture.
y = 1, you predicted that it is a "cat" picture.
y = 1, you predicted that it is a "non-cat" picture.
y = 1, you predicted that it is a "non-cat" picture.
y = 1, you predicted that it is a "cat" picture.
y = 0, you predicted that it is a "cat" picture.
y = 0, you predicted that it is a "non-cat" picture.
y = 1, you predicted that it is a "cat" picture.
y = 0, you predicted that it is a "non-cat" picture.
y = 1, you predicted that it is a "cat" picture.
y = 1, you predicted that it is a "non-cat" picture.
y = 1, you predicted that it is a "non-cat" picture.
Let’s also plot the cost function and the gradients.
# Plot learning curve (with costs)
costs = np.squeeze(d['costs'])
plt.plot(costs)
plt.ylabel('cost')
plt.xlabel('iterations (per hundreds)')
plt.title("Learning rate =" + str(d["learning_rate"]))
plt.show()
Interpretation: You can see the cost decreasing. It shows that the parameters are being learned. However, you see that you could train the model even more on the training set. Try to increase the number of iterations in the cell above and rerun the cells. You might see that the training set accuracy goes up, but the test set accuracy goes down. This is called overfitting.
## 6 - Further analysis (optional/ungraded exercise)
Congratulations on building your first image classification model. Let’s analyze it further, and examine possible choices for the learning rate $\alpha$.
### Choice of learning rate
Reminder: In order for Gradient Descent to work you must choose the learning rate wisely. The learning rate $\alpha$ determines how rapidly we update the parameters. If the learning rate is too large we may “overshoot” the optimal value. Similarly, if it is too small we will need too many iterations to converge to the best values. That’s why it is crucial to use a well-tuned learning rate.
Let’s compare the learning curve of our model with several choices of learning rates. Run the cell below. This should take about 1 minute. Feel free also to try different values than the three we have initialized the learning_rates variable to contain, and see what happens.
learning_rates = [0.01, 0.001, 0.0001]
models = {}
for i in learning_rates:
print ("learning rate is: " + str(i))
models[str(i)] = model(train_set_x, train_set_y, test_set_x, test_set_y, num_iterations = 1500, learning_rate = i, print_cost = False)
print ('\n' + "-------------------------------------------------------" + '\n')
for i in learning_rates:
plt.plot(np.squeeze(models[str(i)]["costs"]), label= str(models[str(i)]["learning_rate"]))
plt.ylabel('cost')
plt.xlabel('iterations')
frame = legend.get_frame()
frame.set_facecolor('0.90')
plt.show()
learning rate is: 0.01
train accuracy: 99.52153110047847 %
test accuracy: 68.0 %
-------------------------------------------------------
learning rate is: 0.001
train accuracy: 88.99521531100478 %
test accuracy: 64.0 %
-------------------------------------------------------
learning rate is: 0.0001
train accuracy: 68.42105263157895 %
test accuracy: 36.0 %
-------------------------------------------------------
#### Interpretation:
• Different learning rates give different costs and thus different predictions results.
• If the learning rate is too large (0.01), the cost may oscillate up and down. It may even diverge (though in this example, using 0.01 still eventually ends up at a good value for the cost).
• A lower cost doesn’t mean a better model. You have to check if there is possibly overfitting. It happens when the training accuracy is a lot higher than the test accuracy.
• In deep learning, we usually recommend that you:
• Choose the learning rate that better minimizes the cost function.
Congratulations on finishing this assignment. You can use your own image and see the output of your model. To do that:
1. Click on “File” in the upper bar of this notebook, then click “Open” to go on your Coursera Hub.
1. Add your image to this Jupyter Notebook’s directory, in the “images” folder
1. Change your image’s name in the following code
1. Run the code and check if the algorithm is right (1 = cat, 0 = non-cat)!
# START CODE HERE ## (PUT YOUR IMAGE NAME)
my_image = "my_image.jpg" # change this to the name of your image file
## END CODE HERE ##
url_img = 'https://raw.githubusercontent.com/andersy005/deep-learning-specialization-coursera/master/01-Neural-Networks-and-Deep-Learning/week2/Programming-Assignments/images/my_image.jpg'
urllib.request.urlretrieve(url_img, my_image)
# We preprocess the image to fit your algorithm.
fname = my_image
my_image = scipy.misc.imresize(image, size=(num_px,num_px)).reshape((1, num_px*num_px*3)).T
my_predicted_image = predict(d["w"], d["b"], my_image)
plt.imshow(image)
print("y = " + str(np.squeeze(my_predicted_image)) + ", your algorithm predicts a \"" + classes[int(np.squeeze(my_predicted_image)),].decode("utf-8") + "\" picture.")
E:\Anaconda\lib\site-packages\ipykernel_launcher.py:9: DeprecationWarning: imread is deprecated!
imread is deprecated in SciPy 1.0.0.
Use matplotlib.pyplot.imread instead.
if __name__ == '__main__':
E:\Anaconda\lib\site-packages\ipykernel_launcher.py:10: DeprecationWarning: imresize is deprecated!
imresize is deprecated in SciPy 1.0.0, and will be removed in 1.2.0.
Use skimage.transform.resize instead.
# Remove the CWD from sys.path while we load stuff.
y = 0.0, your algorithm predicts a "non-cat" picture.
|
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http://apmonitor.com/wiki/index.php/Main/OptionApmCtrlUnits?action=diff&source=n&minor=n
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Main
## Main.OptionApmCtrlUnits History
June 08, 2017, at 11:28 PM by 10.5.113.159 -
Changed line 18 from:
to:
June 08, 2017, at 11:27 PM by 10.5.113.159 -
Changed lines 5-6 from:
to:
June 01, 2017, at 06:56 AM by 45.56.3.173 -
(:title APM.CTRL_UNITS - APMonitor Option:) (:keywords APM.CTRL_UNITS, Optimization, Estimation, Option, Configure, Default, Description:) (:description Model time units (1=sec, 2=min, 3=hrs, 4=days, 5=yrs):)
Type: Integer, Input
Default Value: 1
Description: Model time units
1=seconds
2=minutes
3=hours
4=days
5=years
CTRL_UNITS are the time units of the model. This option does not affect the solution but does affect the x-axis of the web plots. The time displayed on the web plots is shown according to the HIST_UNITS option but scaled from the model units as specified by CTRL_UNITS. The valid options are 1=sec, 2=min, 3=hrs, 4=days, and 5=yrs. If CTRL_UNITS=1 and HIST_UNITS=2 then the model is in seconds and the web plots have model predictions and measurements that are displayed in minutes.
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https://arxiv.org/abs/1402.5573
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astro-ph.EP
# Title:Orbit and Bulk Density of the OSIRIS-REx Target Asteroid (101955) Bennu
Abstract: The target asteroid of the OSIRIS-REx asteroid sample return mission, (101955) Bennu (formerly 1999 RQ$_{36}$), is a half-kilometer near-Earth asteroid with an extraordinarily well constrained orbit. An extensive data set of optical astrometry from 1999--2013 and high-quality radar delay measurements to Bennu in 1999, 2005, and 2011 reveal the action of the Yarkovsky effect, with a mean semimajor axis drift rate $da/dt = (-19.0 \pm 0.1)\times 10^{-4}$ au/Myr or $284\pm 1.5\;\rm{m/yr}$. The accuracy of this result depends critically on the fidelity of the observational and dynamical model. As an example, neglecting the relativistic perturbations of the Earth during close approaches affects the orbit with $3\sigma$ significance in $da/dt$.
The orbital deviations from purely gravitational dynamics allow us to deduce the acceleration of the Yarkovsky effect, while the known physical characterization of Bennu allows us to independently model the force due to thermal emissions. The combination of these two analyses yields a bulk density of $\rho = 1260\pm70\,\rm{kg/m^3}$, which indicates a macroporosity in the range $40\pm10$% for the bulk densities of likely analog meteorites, suggesting a rubble-pile internal structure. The associated mass estimate is $(7.8\pm0.9)\times 10^{10}\, \rm{kg}$ and $GM = 5.2\pm0.6\,\rm{m^3/s^2}$.
Bennu's Earth close approaches are deterministic over the interval 1654--2135, beyond which the predictions are statistical in nature. In particular, the 2135 close approach is likely within the lunar distance and leads to strong scattering and therefore numerous potential impacts in subsequent years, from 2175--2196. The highest individual impact probability is $9.5\times 10^{-5}$ in 2196, and the cumulative impact probability is $3.7\times 10^{-4}$, leading to a cumulative Palermo Scale of -1.70.
Subjects: Earth and Planetary Astrophysics (astro-ph.EP) DOI: 10.1016/j.icarus.2014.02.020 Cite as: arXiv:1402.5573 [astro-ph.EP] (or arXiv:1402.5573v1 [astro-ph.EP] for this version)
## Submission history
From: Davide Farnocchia Dr [view email]
[v1] Sun, 23 Feb 2014 02:48:49 UTC (737 KB)
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https://thebasepoint.wordpress.com/
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### art:science::?!:!?
It’s a colored brain. Image by Zeynep Saygin, courtesy of MIT’s Koch Institute.
When I see an art+science event announced, I brace for disappointment. Usually I go anyways because I’m curious to see the failure mode. Which will it be?
1. Art loosely inspired by science (Heisenberg’s uncertainty principle and Einstein’s relativity and everything is chaos man).
2. Science *as* art (a colorized photo of a cancer cell, a video of a chemical reaction).
3. Art as an illustration of science (a drawing of a cell or a nucleus, a rendition of a particle collision).
4. Science as a means of production for art (I took data from cosmic rays and ran them through five algorithmic filters to make this soundtrack, or EEG traces to color a print).
3 and 4 are inoffensive, but don’t warrant special treatment. They are just sharing best practices and tools. MIT’s Koch Center displays images which might be tarred as 1, but their press talks about the connection between science and engineering, not science and art.
Anyway, it was a great relief when this morning’s panel at swissnex began with the choreographer Gilles Jobin laying out an axis:
<———————————————————————————->
illustration coherence inspiration
In coherence, there is some part of the art piece which directly corresponds to a scientific concept. Like in a good metaphor, a part of one thing is precisely aligned with a part of another, but neither whole is subordinate.
Jobin came to San Francisco by way of CERN, home of the Large Hadron Collider, the most intricate engineering project ever. (Sorry iPhone.) He spent three months as a resident artist, talking with particle physicists and engaging in his own movement research. I think the dance he subsequently produced does occupy that middle ground.
A dance produced by an artist-in-residence at CERN. Movement premised on atomic dynamics. Can you see that residue?
Jobin is primarily concerned with the generation of movement, and took from the physics a few conditions (or algorithms or formal exercises) to set his dancers. For example:
-Positively charged particles repel, and deflect before collision. (In fact, all physical forces act ‘at a distance’; direct contact is an illusion of the macroscopic.)
-Molecules are constantly vibrating
-Magnetic fields cause atoms to align
A long residency gives time for subtlety, to get beyond the pat explanations which scientists tend to give the public. Take the magnetization of iron. In a chunk of metal, every atom spins in some direction (the direction of a spin is the axis of rotation, think of the earth). The usual story is that turning on a magnetic field whips all the atomic spins into alignment, pointing uniformly, say, to the right.
– – – – –
– – – – –
But the field actually induces a preference, a mere statistical tendency for the atom to wobble in one way.
– / – / –
– \ – – \
The idea of a tendency getting turned on and then amped up over time is more physically correct and more kinetically interesting.
Jobin was also surprised to learn that physicsts think about kinds of symmetries. He had previously thought of symmetry as a binary idea; a thing is symmetric or not. (Mathematicians classify symmetries too; eg: there are exactly 17 kinds of symmetry possible in repeating planar patterns like Turkish tiles or Navajo blankets. I’ve been meaning to do a sweet html5 illustration of this, we’ll see if future Josh gets his ish together.)
In 2012, installation artist Julius von Bismarck was the (first) artist in residence at CERN. As part of his duties, he hosted a few interventions with the locals. First, he had a “coffee in the dark” discussion, where in a pitch-black room physicists talked about how they imagine the shapes of the things they study. Ten dimensional symmetry groups, subatomic particles, etc. He also taught an art-school-in-30m class, where after a brief discussion of form and style the participants had to make a piece which he then subjected to a scathing critique (“cheesy, naive…”). A taste of his own harsh training. Jobin, for his part, decided to infiltrate the library extremely slowly. For 3 hrs dancers were glacially rolling across the floors and slowly sliding along the bookcases. Hardly anyone noticed.
Physicists can be rather disinterested in people. The universe is made of particles moving according to certain laws; earth is an incidental mote in the cosmos. Showing a photograph of the CMS detector at CERN, a physicist said “to get an idea of the size of the 14,000 ton detector, look how small the human being working on it appears.” The concern with the invisible and impalpable, with the long time, is different from that of the choreographer; no feelings! (Also, no aesthetics…have you ever seen a slide from a physics preso?) For Julius, who lives in the incestuous Berlin art world, inhabiting a place where human concerns were secondary was just like whoa.
It seems to me like the primary benefit of interdisciplinary interaction is those moments where you realize that other people pay attention to different parts of the world, sort of like the benefit of travel. By spending time with people whose givens and goals are different than yours, your mind opens up. The point of studying abroad is not to take the language you learn or contacts you make and start some international business or translation service. I have yet to write any math poems, but spending years in close quarters with a poet did change me.
Lately, I’ve been doing some dancing and hanging out with dancers. Different modes of interpersonal communication, different things to look for, that click-click-click feeling of accessing a new dimension of being. (I mean dimension literally. Separating the motion of the core from the hips and the shoulders adds a degree of freedom. The phase space of the human skeleton is about 200-dimensional.) Will that affect my mathematics directly (maybe working on algorithmic dance, like Cunningham choreo, or moduli problems of jointed rigid bodies)? Possibly, but that feels like the minor effect. It’s just improving my life, and I can’t help but think that the place in the of the mind where ideas are born is becoming more fertile. It’s sort of like meditation: the benefits of regular meditation for a host of physiological, emotional, and mental indicators are well-documented, but it’s not like you need to work on something about or inspired by meditation.
The cool thing about the CERN artist residency is that they are investing in the growth of the artist as a person, and trusting that it will lead to better art. The US Fullbright programs are similar in spirit; it seems like they deliberately avoid asking you to execute the ostensible project.
Next step: who is going to fund three months for a scientist to visit Jobin’s studio? Have you seen the way those people move?
Coda: Another piece of Julius von Bismarck that I’m kind of in love with is called Punishment, in which the artist whips nature.
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### Bowman v. Monsanto Co.
Last week, the supreme court ruled that “a farmer who buys patented seeds may [not] reproduce them through planting and harvesting without the patent holder’s permission.”
Soy plants with their beans/seeds (Photo courtesy indianagrain.com)
The patented seeds in question are Roundup Ready soybeans, a strain engineered by Monsanto to be resistant to a broad-spectrum herbicide called glyphosate, also developed by Monsanto. At first, I thought this was a case about genetically modified crops–patents, GM, corporate litigation, big agra, and rivers of herbicide go together, right? And the gene for glyphosate resistance had been inserted into soybeans by infecting them with a DNA-altering bacterium. I’ve been learning a bit about the science of genetic modification, which should probably be called technology given how ubiquitous it is (Harvard scientists make GM mice whose neurons fluoresce in a 20-color brainbow.) So I got all excited to talk about the history of genetically-modified plants, and the maybe-genius maybe-disastrous uses scientists, in universities and multinationals, have in the pipeline.
But this is really a case about patenting seeds, cells, and plants, which has been going on at least since the Plant Patent Act of 1930. That law does what it says (which is rare among laws, cf No Child Left Behind) and explicitly allows for the patenting of plant varieties. Clarified in 1954 to include seeds, mutants, and hybrids, the law has been used to patent more than 20,000 distinct species of plant. Most recently, plant patent #23,600 was awarded to a British woman named Brenda Bowyer for (conventionally) breeding a variety of helichrysum she christened “Ember Glow,” after the way its red bulbs orange with age. The delicious and now popular Honeycrisp apple was the result of three decades of iterated crossing by hand-pollination and careful selection at the University of Minnesota; the plant was patented in 1998, and for the next 20 years, the U of M charged \$1.30 per seedling. In 2008, the US patent expired, and now anyone can sell the seedlings/branchings royalty free. Apple breeding is a pretty well-functioning part of the plant-patent world, and is responsible for the disturbing turnover of apple varieties since I was a kid (those Piñata apples have been showing up a lot lately–patented in 2000).
It turns out, though, that none of the famous GM crop patents, including the Monsanto patent on glyphosate-resistant soybeans, are actually plant patents. No, those are just ordinary (utility) patents which happen to be on plants. This subtlety, plant patent vs patent on plants, is pretty typical legalese, and as as all my lawyer and would-be lawyer friends well know (congrats on finishing xL), the whole case can ride on such distinctions. If Monsanto’s patent had been a plant patent, the farmer would have been a clear victor and the case would never have made it out of district court.
So who is the farmer here, what did he do, and why is it, in the unanimous opinion of our supreme court, obviously illegal?
### Mould broth filtrate
…for convenience, and to avoid the repetition of the rather cumbersome phrase “Mould broth filtrate,” the name “penicillin” will be used.
When Alexander Fleming noticed that a colony of mold had contaminated his tray of staphylococcus bacteria, and that the bacteria near the mold had begun to die (or lyse), he did some science. He grew the mold in five kinds of sugar broth (including lactose+glucose=milk+honey), then poured a bit of each broth on a tray containing the bad -coccuses (strepto, pneumo, gono, staphylo) and watched them retreat. He tried filtering out the mold, boiling the mixture, and then diluting it 600-fold, and still it killed bacteria. Injects huge quantities of filtered moldy broth in mice and then rabbits–seems nontoxic. Upgrades to putting drops into some bold man’s eye every hour for a day–no problem. The mold-water kills bacteria and is safe for humans. Time to write the paper and tell everyone.
But what to call the elixer? As he later writes in the intro, the phrase “mould broth filtrate” is rather cumbersome, not to mention seriously gross. As drug companies know, a sexy name is key to convince people to put something in their bodies (compare “botox” to “botulinum toxin”). But “mold” is also too general, as a half-dozen other molds he tested had no anti-biotic effects (asparagus soup is good for you, aspergillus fumigatus soup, not so much). He knew the name he picked would become famous, and as any political spinster or derridaian graduate student can tell you, the choice of name matters a great deal.
There were a few ways he could have selected a name.
1. Named after a person
It would be presumptuous to call it the “Fleming solution,” so he would presumably pick someone vaguely related, perhaps a teacher or already-famous person. Consider the Poisson spot, named for its greatest skeptic, or any other instance of Stigler’s law. Some ecologist named a blind precambrian arthropod “krygmachela kierkegaardi” after her favorite philosopher.
2. Named after a function
“Bacteria-killing mold” or “staph-lysing mold” or some latin equivalent. Compare “anteater.”
3. Named after an attribute
“Yellow-sporal solution.” Compare “three-toed sloth.”
4. Named after the first place you saw it
Strange in a lab, popular with diseases and lifeforms. “West nile virus” or “brazil nut.”
5. Named with an arbitrary combination of sounds.
“Quark” or “bandersnatch” or “prozac.”
Fleming decided to go with “penicillin” for the “mold broth filtrate,” derived from the name of the mold itself. Of course the Petri surprise had given itself no name, but by growing other molds known to inhabit laboratory air and comparing their appearance and lethality to his new dish, he determined that it was at least closely related to penicillium rubrum. Where did this nice latin root come from? Penicillus means paintbrush (type 3).
A light micrograph of penicillium spores.
I think that a big merit of using latin names in science is that they become free-floating signifiers. Proper names work this way too, and are popular in math–my last paper was on Khovanov homology. If you don’t know the language/person involved, then it’s just a collection of sounds whose meaning can evolve over time as your understanding of the object changes. Such is not the case for Penicillin Binding Protein.
After Fleming discovered that this mold could kill (some) bacteria while leaving human cells unharmed, people wondered just how it worked. Lots of science and about 40 years later, it became clear that penicillin disabled a bacterial protein, which was immediately named “penicillin binding protein”. But that’s totally unfair to the protein. It did its job, which turns out to be linking chains in the cell wall, long before penicillin came around. The fact that penicillin could distract the protein, leaving weak cell walls which would break like a burst like a levee under stress, is hardly a definitive feature of the protein itself. And now when these bacteria are studied with absolutely no penicillin around, a key enzyme is named after its number one enemy.
It’s like calling Lou Gherig the “amyotrophic lateral sclerosis binding man” or your brain “stroke-bait.” Just rude.
I think that’s why acronyms are so popular in the biology literature, why all the papers talk about PBP instead of penicillin binding protein. By dropping any pretense at description, “PBP” attempts to specify without prejudice about form or function or meaning. Unfortunately, this can make reading biology (and corporate reports) a pretty surreal experience, when PBP coactivates PPARy in the ARC complex.
Objectively and ahistorically yours,
-JDB
### Grandpa’s genes
Are you genetically related to your grandfather?
I know I am. I’m male, so my Y-chromosome came from my dad (left). And he’s male too, so his Y-chromosome came from his dad (right).
But I’m getting worried about my sister. I know she got an X from dad, which was grandma’s to start. There were 22 other chromosomes in the lucky spermatozoon which fertilized the egg which became her first cell. Each of those were picked at random–a 50% chance it came from grandma and a 50% chance it came from grandpa. Could they all have come from grandma? Could she have missed all 22 chances at inheriting grandpa’s genes? It’s not super likely–the probability is $1/2^{22}$, or about one in four million.
But there are ~160 million women in America–could it be that 40 of them are unrelated to their biological grandfather?
I thought so, until I remembered chromosomal crossover–the dance where your genes do-si-do. Before the climactic moment of meiosis, when all of my dad’s chromosome pairs lined up, then got yanked into two bunches (one of which begat my sister), before that, both sets of grandparental chromosomes were hanging out together. On occasion, they would swap pieces (when called to do so by recombinase proteins).
Hoping to preserve the idea that there might be these 40 pseudo-granddaughters wandering around, I checked out just how often. According to a genetical study of a few hundred icelandic families, between generations there is a one percent chance of a crossover in each stretch of a million DNA base pairs. There are about 3 billion base pairs in the genome, so this makes a no-crossover generation pretty unlikely; one in a trillion zone. So maybe this has happened to an ant, but never to a human.
Takeaway: for better or worse, you are related to your relatives.
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http://lambda-the-ultimate.org/node/5405
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## Unsoundness
Hi, I wonder if someone can help resolve the conflict described below.
My system is an Algol like language which supports both functional and procedural code.
Now, I hate the way C handles lvalues, it doesn't extend well, one has to make horrible rules
and list all possible l-contexts, and attempts to do this in C++ are an abysmal failure.
My solution is elegant! Consider a record:
(x=1,y=42.1)
which has type
(x:int, y:double)
then this is a first class value, and the field names are projections:
x (x=1,y=42.1)
Since I have overloading there's no conflict with the same field name in some other record,
the field name is just an overloaded function name.
To make it look nicer you can use reverse application:
(x=1,y=42.1) . x
Now, to get rid of lvalues we introduce pointer types and variables so that in
var xy = (x=1,y=42.1);
&xy <- (x=2,y=43.1);
This is really cool because & is not an operator,
just a way to write the value which is the address of a variable.
We use a procedure written as infix left arrow which takes a pointer to T
as the first argument and a T as the second, and stores the value at the specified address. So its all values.
To assign to a component, we introduce a second overload for each projection that takes a pointer argument and returns a pointer:
&xy . x <- 3;
This works for other products as well (tuples, arrays and structs).
So, we have a purely value based semantics and a sane type system.
In particular we have a very nice rule that relates values and objects.
So far so good, but now I have another feature called "compact linear types"
which are packed encodings of any type defined by the rule:
unit is compact linear, and sum, product, or exponential of a compact linear type is compact linear.
A small compact linear types is one that fits in a 64 bit machine word.
So for example the type 3 * 4 is a single 64 bit value which is a subrange of integer 0 thru 11.
Compact linear types with integer coercions used as array indices give polyadic arrays
(rank independent array programming).
The problem is .. compact linear type components are not addressable.
Projections functions work fine, but there are no overloads for pointer projections.
And so the conflict: polymorphic pointer projections are unsound:
proc f[T,U] (r: &(T,U)) (v:T)) { r.0 <-v; }
will not work if r is a pointer to a compact linear object. I can think of three solutions:
(1) invent a new pointer type (destroys uniform pointer representation property)
(2) have distinct product, sum, and exponential operators for compact linear types
(3) use the same operators but introduce pack and unpack operations
## Comment viewing options
For me, pointers would be an abstract semantic concept, so I'd have to go with (1) and then deal with the repercussions for representations (uniform pointer representation is an observation the compiler makes in a specific context). But if you want pointers to be an operational concept, always a machine word, then you probably want some combination of (2) and (3).
Didn't C++ go through a similar debacle with bit vectors?
### Pointers
At present pointer type &T is typed version of a linear machine address.
Now, one of the problems we have is that there is an unbounded set of mutations on the store a pointer points at, so it seems impossible to abstract them without performance loss. For example increment the value pointed at is an atomic read/modify/write operation that can't be broken down into a get/set sequence.
Furthermore C bindings can be polymorphic on pointers for example:
fun incr[T] : &T = "++*$1"; (where$1 is the argument) and this won't work unless we can distinguish C compatible pointers and the extended type needed to address a compact linear type.
The problem here is that pointers have two operations, get and ref and ref is a lot more general that mere set.
Now, I could do the incr thing by adding the following overload:
fun incr[T:COMPACTLINEAR]: &T = " ....";
if only there were some way to say that a type is compact linear (as indicated).
But then we're looking at either subtyping and classes of types of meta-typing or kinding, and that's a major system upgrade I don't know how to do right. The compiler *does* know when a type is compact linear, and Felix instantiates away all type variables so at least the back end knows.
### Arrays
Surely pointed at memory can be abstracted to three operations, 'read', 'write' and 'mutate'. Read and write can use 'get' and 'set'. For 'mutate' you need reference types. Given a type 'Ref A' any operation on the value actually happens at the address pointed to, so:
f (Ref x) = ++x
Would increment the value pointed to, not the pointer. What we want to do is separate dereferencing from the structure.
Edit: Therefore a mutable array would need to provide addressing and dereferencing, so if "p" is the base pointer and "x" is the index in the array, then the final address is "p + x". This then needs to be dereferenced, 'C' uses '*', but I will use 'deref':
++deref(p + x)
would increment the value at the address pointed to by "p + x". The point is all addresses are just plain integers of the appropriate size (we consider them as offsets from zero, but like C/C++ we can encode the type of the thing pointed to in the pointer type so ensure we can only point to the start of multi-word structs). We cannot express the type of 'deref' in 'C', but we can in C++:
template <typename T> &T deref(*T)
### references
I don't see how this helps apart from the fact the whole idea was to get RID of references :) In fact you cannot express it in C++, because &T is not a type, no matter what the C++ Standard says.
You should just think "bitfield". If you want to mutate a bitfield of 3 bits the type is 8 so we have this pointer type in Felix:
&8
but this is not enough information, because we do not know WHERE in the machine word those 3 bits are.
So actually we need a pointer to the machine word and 3 extra machine words to determine the location for an arbitrary compact linear type. The formula is
v = (w - d) / s % m
where w is the word, d is an offset which is required for sums, s is the generalised right shift amount obtains by division, and m is the generalised mask, obtained by modular remainder. For example if the type of a value is
2 * 8 * 5 + 52
then
v = (w - 52) / 5 % 8
is the value of the three bits.
So unless I generalise the representation of pointers, my type system is unsound.
Since compact linear types are statically typed, it is enough to use two pointers, one to the word containing the component, and one to the triple of words d,s,m.
If I do that C compatibility is out the window. So I have to find a way to use the generalised pointers when required and optimise the second machine word away when not required. C of course doesn't have general compact linear types, but it DOES have bitfields.
### Proxy
I think I like (3) if I understood the problem correctly. (1) looks like redundance, and (2) also. But maybe that's just my impression.
I'm not sure if this helps, but you could be interested in Javascript Proxy solution. Basically, it stands for invocation of custom code handler upon setting or getting (or some other operations) an object property value. Proxy sounds to me as generalized (3) solution.
### Proxy
There are two difficulties with Proxy: the first is that it requires a fixed set of operations. The second is probably more serious: how does this generalise to support pointer projections? Remember a record has named fields so we just overload the field name with argument types T and &T. A compact linear product has projections too, but how do we overload them for an abstract type?
Remember the whole point of structural typing, and types like 3 * 4, is that the type dictates the operations based on its structure. I have no idea how to preserve the structural information with an abstract type. If there's an abstraction here it's something like "product formation".
### some questions
I'm not sure if I get these "compact linear types" (CLT). Why shouldn't the static typing system be able to distinguish them from other types? How do they differ from regular structure types and why do you need them in a first place? What do you mean by "pointer projection"? And what is the general internal byte structure of CLT? Could you have internally a set of pointers to each element (stored elsewhere) inside CLT, instead of a set of multibyte values? That way each pointer-to-element in the set would have a fixed length, and all you would need to know is element count.
### compact linear types
A compact linear type is a generalisation of "bit fields". For products, consider a type like 3 * 4 * 5, this means the first component has 2 values, the second 4, and the third 5. These are sums of units, eg 3 = 1 + 1 + 1 where 1 is the type unit with value ().
A good example perhaps is a clock: 60 * 60 * 24. The time in seconds, minutes and hours (only sums don't automatically have addition).
The most well known unit sum is 2, which is also called bool. Most language use nominal types for sums, but Felix also has anonymous structurally typed sums, and special notation for sums of units.
Compact means the values are bijection on a subrange of integer 0 .. n-1, and linear just means integer.
The point is by coercing a compact linear type to an integer you can add 1 to it, and then convert back, and thereby iterate over all possible values. In particular if you have an array with index type, say, 3 * 4 * 5, so it is rank 3, you can fold over all the elements without needing to know the rank.
There are other obvious uses. For example plain old 2^30 gives you a 30 bit unsigned integer this way, which is also a bit array of 30 bits. Although expensive to access the components, in some applications (eg networking) data compression is more important than decoding time.
### Type "2 * 4 + 6" as not being bijection?
So, compact linear type stores "2 * 4 + 6" type value as an integer value between 0 and 14? If I got it right, we want to be able to:
1. convert component values to internal CLT format; and
2. convert internal CLT format back to component values
Ok, that makes sense, but I don't see this as bijection. For example, an internal value, being of TYPE "2 * 4 + 6", could be "8", but the same "8" can stand for two different COMPONENT COMBINATIONS:
1. "2 * 2 + 4"; or
2. "1 * 4 + 4"
which makes the whole system as not bijective. If this theory holds, the internal format for storing CLT shouldn't be just plain bounded value range, it should also carry some other informations to make the system bijective. But then, are we loosing an essence property of fast itterating over all possible CLT combinations?
### We can have
.. an algebra (as you proposed above) to injectively connect component combinations to internal values, I guess you did the math behind...
I can see the purpose of having a product of values, but what would be the purpose of having a sum of values or exponential values?
### sums and exponentials
Well the original motivation is for array indices, which is why 64 bit limitation is reasonable. So a typical thing is like this:
var x : (double ^ 5) ^ 3;
This is an array, length 3, of arrays, length 5, of doubles. A double would be found by the formula
x . i . j
where i:3 and j:5. But now consider this isomorphic type:
var y: double ^ (3 * 5);
which is accessed by
y . (i,j)
and I get confused remembering the ordering. The index is called a multi-index and this data type is called a matrix. A matrix is NOT an array of arrays but it is isomorphic to one. And now consider
var z : double ^ 15;
which is an ordinary linear array. That one has only a *single* index so a fold over a linear array of doubles will also fold over a matrix the same size if you coerce the type first.
So what would this mean:
var a : double ^ (2 + 4)l;
Well it means you have two arrays, one length 2 and one length 4, next to each other making a total length of 6. The last value looks like
a. ( case 1 of (2+4) (case 3 of 4)
which is pretty messy looking. (In Felix the case index is 0 origin).
### Seems sound
Now, that the compact linear type system seems sound to me, may I propose the following (I was holding this before the check):
You know how to hold a compact linear type inside a regular type, but how about other way around? Isn't a regular type value just a form of CLT where the length of CLT is just one element? If you could manage to hold regular types inside this one element CLT, you could have any type wrapped inside CLT type. So, for complex CLT-s, you would have regular type values wrapped inside CLT, and those regular types could again can hold another CLT-s. I think this tweak deals with interal byte representation of CLT-s and I don't know what impact to performance it would have, but it looks like a fractal to me and I like fractals :)
A further thought after realizing what sums, products and exponentials are is: maybe you could express any type as plain CLT and have just a single kind of treatment for pointers, element extractions and other operations?
### 2 * 4 + 6
You seem to be confusing sum and product types. With (2*4)+6, we have either a value from type (2*4) on the left OR a value from type 6 on the right, not components of both. But within the type (2*4) we'd have a component for the 2 and a component for the 4 (thus three bits). Or translating to a common language:
type (a + b) = Left a | Right b type (a * b) = Pair a b
There are multiple possible encodings. But the range 0-13 can encode all the possible values of (2*4)+6. So if it's 0-7 for the (2*4) and 8-13 for the (6), the value 8 would mean the first choice of 6.
Obviously the encoding will be dependent on the type structure, since that (6) could be a (2*3) or a (1+2+3) or a ((2*1)*(0+(3+0))) or similar.
what would be the purpose of having a sum of values or exponential values?
A sum of types (not values) is choice/conditional. The trivial example is booleans ((1+1) or False | True or Left () | Right ()), or optional values ((1+a) or None | Some a or Left () | Right a).
Exponentials correspond to functions, an arbitrary translation from a→b can be encoded as a number less than b^a. For example (Bool*Bool)→Bool (aka (2*2)→2) covers every possible binary boolean function - there are only 16 of them.
### I see,
thanks for the simple explanation.
Here is something to think about: I cannot help not to connect CLT solution to a parsing technique that just came to my mind. We can use products for sequences and sums for alternations, and pack them in CLT format. Now, if we can iterate through all the combinations, just by simply incrementing a CLT internal value, then by extracting components in each iteration we could get all possible parse searches, which would be used to construct a parse forest.
### parse forest
Yes, a CLT is a limited kind of regexp (without recursion but with finite iteration due to exponentials).
But then, a type is nothing more than a grammar. Alternatives are sums, sequences are products. And recursion is recursion :)
Alternatively, a grammar is nothing more than a type.
And what do types do? Well they define a set of possible paths you can use to explore some data.
Everything in CS and maths is related. Sometimes the relations are hard to see or express so mathematicians invented Category Theory to makes sure NO ONE could understand it.
### fractal grammars
I like seeing grammars as fractals of all possible programs that some language can hold. Wow... How many combinations... It would be interesting to define a program, and then somehow to automatically find its equivalent that is optimized either for speed, either for memory usage. I've heard of "Simplex method" somewhere, but I never made myself to examine it. And there is also some funny called method from math theory, "jumping from rock to rock" in a rough translation from Croatian, dealing with the shortest path between two rocks. "Monte Carlo" method name also comes to my mind, I don't know why...
I think it shouldn't be so complicated, all we have to do is to state equivalences between sets of code fragments in some language, input an unoptimized code, construct a code fractal, and then run a statistical analysis, waiting for the result.
Anyway, I think that we can expect an exciting future with designing programs. Imagine getting a program that is proven that it can't get any faster... or smaller... Wow again...
I just hope that halting problem undecidability is not in our way.
### Undecidability
In general, it is :-)
What you are describing really IS done by low level optimisers. You look at several possible sequences of machine instructions which do the same thing, and calculate which is faster (no one gives a hoot about size any more only speed, but it turns out that smaller is faster on modern processors because of caching).
Unfortunately, static analysis is almost impossible because no one is going to say how many clocks an instruction takes! It's so variable, because the hardware people do their own optimisation, defeating compiler optimisations.
Some code, such as the Atlas math kernel, solve this by actually running competing examples and building the library with the winner. It takes over 24 hours to install Atlas on a medium speed machine.
### Henry Massalin
I think that you would find this paper by Henry Massalin quite interesting. There is a GNU implementation of the technique somewhere, although it does not scale very well.
### Interesting
Interesting how some of optimizations are not even close to what would one expect (as a combination of instructions). Avoiding jumps sometimes seems inconceivable by a human thought.
### sums
I know what a sum type is :-) At least, in the usual functional programming sense. Your calculation is the same as mine.
In Felix the exponential written A^B is an array. For example:
var x : int ^ 3;
is an array of 3 integers. The 3 there is a type, the type of the array index. It a synonym for 1 + 1 + 1 = unit + unit + unit. This variable:
var y = int * int * int;
is the exact same type. This is a design decision, that the isomorphism should be an identity. It means that arrays are just a special case of tuples. The type written
3 -> int
is a function. So both arrays and functions are exponentials, they're both mappings***. The difference is arrays also support mutation, functions do not:
&x . 0 <- 42;
assigns 42 to the first component of the array x.
As a value, however, the array is purely functional.
The interesting thing about Felix arrays is that the index can be ANY compact linear type. As it happens if the index is a sum type this corresponds to array concatenation.
The key point about compact linear types being compact and linear and small enough to fit into a machine word is that you can then fold or map over the array with a single linear operation, independently of the index type. All you need to do is coerce the index type and the fold or map (or whatever) adapts.
*** its annoying that a function f applied to a value v is written f v. However an array a indexed by i is written i a. In fact, this is a shorthand, the real operation is an application of a projection number i to the array a. So the array is an exponential but it is not applied to the index, the index is applied to it. I wish I could see a clean way around this conflict.
### Interesting
I'm not sure if part of this is a good idea, though. Isn't it dangerous to think of a*b and b*a as identical types? Seems like you're missing a chance to report a likely error.
So the array is an exponential but it is not applied to the index, the index is applied to it.
Hmm, but does (a i) work as long as you're only interested in treating a as a function? My thinking is along the same lines as yours in many respects. Felix seems interesting. I wish it were pure :).
### symmetry
a*b and b*a aren't identical.
You can do a coercion chain:
(3 * 4) :>> 12 :>> (4 * 3)
So you're explicitly applying two isomorphisms. If you're doing this to a matrix index then you're changing the scanning order if you're using a pair of loops. This is physically safe.
It's not clear if it makes sense. One could even weaken the rule. For example why not allow
12 :>> 10
I mean that just chops the end off. Quants often get slices of matrices.
So the net result is that reshaping coercions are more powerful than one might like, they can do a bit more than you can do with Jay's method which only allows applying associators to data functors.
As to purity: as in Ocaml, you can write pure code. What's more, you can write pure functions which use dirty impure internals which do not escape. Even more important, using coroutines there is a strong notion of purity even for imperative code. For example:
chip series
connector io
pin inp: %<int
pin out: %>int
{
var sum = 0;
again:>
sum += x;
write (io,out, sum);
goto again;
}
This is imperative code but it is obviously pure. It has no side effects. And it does something you cannot do natively in a functional programming language. It handles streams.
In general functional systems can't handle coinductive types. Cofunctional systems can. Of course in an FPL you can *model* a sum type, and you can *model* a partial function and you can *model* a stream and you can even *model* state mutation. I mean, Turing complete means you can build an interpreter that can do anything computable. But coroutines handle these things natively. Functional code is purely spatial, that is, declarative. Cofunctional code is temporal. Programming without a space/time continuum is absurd :-) Literally, action is the space/time conversion, you really need both.
So functions are not enough. Yes, we want purity and Felix allows it but does not enforce it because I don't know enough to do that.
### Purity
My take on purity is that what's important isn't building things out of functions, but rather the ability to view mutation as a series of values in time. You're right that having this view and typing it soundly are somewhat orthogonal.
What's a good resource for learning about Felix? The website seems spartan.
### Spartan
Well .. try some links, there's a reference manual and a couple of tutorials online.
And a reference manual (PDF) here
https://github.com/felix-lang/felix/blob/master/felix-ref.pdf
which at 300+ pages isn't quite spartan.
### Thank you - I'll check it out
Jan 20 already - are you in NZ? (Edit: Nevermind, your bio says Australia.)
### Yes
Sydney Harbour to be precise :)
### Yes
Yes, we can convert from a compact linear type to a subrange of integers and back. In fact in Felix, the idea is that conversion, in both directions is a pure type cast, that is, the bitwise representation is unchanged so the performance cost of the conversion is zero.
The encoding is fixed in the compiler. I admit I forget the ordering. The "other information" required given the compiler's fixed algorithm is just the type.
For products, the formula is well known, it is nothing more than an ordinary positional number system for natural numbers. For example the time
hours, minutes, seconds
is just ((hours * 60) + minutes) * 60 + seconds = hours * 3600 + minutes * 60 + seconds * 1.
So the time of day is from 0 to 86399 seconds, for a 24 hour clock. This is obviously a bijection. I forget if you write this hours, minutes, seconds or second, minutes, hours in Felix :)
the type is written
24 * 60 * 60
assuming bigendian ordering (I forget, i might have used little endian).
### You're building yet another language because ... why?
My system is an Algol like language which supports both functional and procedural code.
Your & (pseudo-)operator looks like BCPL's (inherited from CPL's) r-value. For it to work, your variables must have addresses; which means they can't just 'stand for' values in a functional programming/lambda calculus style. Are those addresses to be static or on the stack or on the heap? What about when Garbage Collection shuffles them about? I don't see anything purely value-based.
Have you looked at the Lenses approach for structuring addressable/updatable sub-components within a FPL?
### Another language
Well this project started over 20 years ago, and the critical requirement was to support large numbers of lightweight threads (of the order 100K). The environment was telephony (so one thread per active phone call).
Today, it is still the only language I know of that can do this, apart from Go, and Go is crap (I mean, no parametric polymorphism? Are you kidding?)
So to answer your question: at present pointer types do indeed require addressable store. The addresses will usually be on the heap. The GC is a naive mark/sweep not a copying collector so there is no moving things about. It has to be because the language is designed to bind to C/C++ and it would be too hard if the GC moved a pointer that C/C++ had borrowed.
And hence the problem: bitfields or more generally compact linear type components are not addressable by a single machine address.
Yes, I looked at Bananas/Lens etc, there's some support for some of it.
The "purely value based" comment is meant to mean there are no "lvalues" (C) or "reference types". References are not types. C lvalues are syntax rules that don't generalise.
### Types For Lvalues
A type system is a logic that models permitted semantics. Different logics model different semantics. If the logic models the permitted semantics of references correctly, then that logic can be used as a sound type system for references. To say references are not types is true, but you can model the semantics of references using types, which is all types ever do anyway.
### type system
Type system has to be combinatorial or they're not type *systems*. In particular care has to be taken with polymorphism.
If T is a type, so is T*, a pointer to T. But T& isn't a type because & is not combinatorial. In C++ this comes down to rubbish in templates if your T was say int& then T& becomes (int&)& which is nonsense. On the other hand int** is sane.
In C++ references could be allowed in function parameters, since there it changes the type of the function. That is, the "&" bit is part of the function type, it's not part of the argument type.
### Ref(Ref Int)
There is nothing wrong with "Ref(Ref Int)" it would still look like an Int lvalue. Yes C++ does not get this right, but that does not mean the concept is flawed, just the implementation in C++.
Templates are not a great way to achieve generics either, so I would not use them as an example. Parametric polymorphism is a better starting point in my opinion.
Edit, I agree that pass by reference is part of the function type, but this has the problem that we don't distinguish between mutable locations and values in the type system if we do this. We cannot tell if a variable is a valid lvalue from its type.
It is not being able to tell if a term is an lvalue from its type that results in needing a syntax rules. To do this properly without syntax rules requires being able to determine from the type of any free term whether it is an lvalue.
### Ref
There is nothing wrong with Ref(Ref Int) if Ref is a combinator. As it is in Ocaml. And as Pointer is in C, C++, and Felix.
However it is not a reference in the C++ sense of an lvalue in that case.
In C, lvalue is a syntax rule. In C++, lvalue is a type rule. Its a supreme mess! The C++ rules are not combinatorial and they also happen to be unsound. I tried to stop this crap but failed: C++ has a type thing called a decl_type separately from an expression type (which is separate from a value type!!)
Decl-types are used to do template meta-programming because the type system is totally broken, and you just can't handle all the cases without them. But the result is absurd.
My point is that pointers are first class values, and the pointer symbol in a type is a combinator, which captures the fact that they point at mutable store.
Felix does not require any type rules, nor does it require any syntax rules. More precisely if you have a "var" variable named "x" then "&x" is the name of the pointer to that store. You cannot use "&" in front of an expression or variable of "val" kind. Really a variable IS a pointer, but instead of having to deference it when you want the value stored there, Felix does that automagically and the "&" symbol suppresses the dereference.
If you insist, this is a syntax rule, but there's exactly one trivial rule. You can also get pointers to objects on the heap. The point is to address *components* of a product without any notion of lvalues or reference, one has to do address calculations on the pointer to the whole product to find and add the offset of the component.
Which Felix does using the *same* notation as used to fetch a component value, only applied to a pointer to the product type instead of the product type.
var x = 1,2;
var x2 = x.1; // x2 == 2
var px2 = &x . 1; // points to second component of x
px2 <- 42; // x == (1,42) now
This machinery is the same as used by C for arrays, however C cannot do this for structs, you have to use offsetof macro. C++ has pointers to members which can do this in a well typed way, however you cannot add pointers to members.
Since Felix uses projection functions, adding offsets is done by functional composition. This is what I mean by saying it's purely functional. All the address calculations are purely functional. Of course when you do a mutation using a pointer its obviously imperative code.
I should explain: there is no problem with variables having addresses.
The problem is that a variable might contain a value of a tuple type such as 3 * 4 * 5 which is a single machine word because its a compact linear type.
Now projections for values:
var x = (1, "Hello"); // type int * string
var i = x.0; // projection 0
var s = x.1; // projection 1
and the same notation for pointers:
var pi = &x . 0; // pointer to int type &int
pi
See? The projection is a PAIR of functions, one applies to a value of some type and one to a pointer. This lets us modify a component of a tuple stored in a variable by calculating the component's address from the variables address.
So now consider:
var clt = (true, false);
True and false are type bool which is 2, so clt is type 2 * 2 which is compact linear and so clt is a 64 bit integer with the low two bits holding the value.
But the bits aren't addressable. So whilst the value projections are OK, the pointer projections don't currently exist.
This is no problem with concrete types. The problem comes with polymorphism.
We don't know if
T * U
is compact linear or not. We can't disallow addressing the components if its not and we can't allow it if they are.
Which means the type system is unsound. (Or incomplete).
My point about (not) needing to invent a whole new language is that usually some other language is already coping with the requirement. (I won't say "solving the problem", because very often "the probelm" is asking the wrong question.) So:
And hence the problem: bitfields or more generally compact linear type components are not addressable by a single machine address.
Have you looked at BCPL's SELECTOR and BYTE constructors (and corresponding operators)? Here http://rabbit.eng.miami.edu/info/bcpl_reference_manual.pdf sections 2.14 and 4.6 for assignment thereto.
Beware that although BCPL is regarded as a precursor to C, it is considerably more 'close to the metal'. (I'm thinking that's a Good Thing in the case you're asking about.)
In particular, BCPL is completely untyped: all rvalues are whole words. It is up to the operator/function as to how that value is treated: INT or CHAR or STRING -- which is a pointer to a VEC. A VEC might contain CHARs one-per-word, or pack them several to a word; that's not type-checked: it's up to the program to treat the VEC consistently.
Pointers are again just whole-word rvalues. So BCPL needs distinct operators to apply a SELECTOR vs a BYTE vs mere dereferencing (monadic !) vs offset dereference (dyadic ! -- for example to index VECs).
Note in that manual section 4.5 'LEFT HAND SIDE FUNCTION APPLICATION', any function can appear on LHS of assignment. For the function/procedure definition, there's a library routine LHS() the function can call to determine whether it's selecting or updating -- the result for LHS() is planted by the compiler.
### Solved
Ok, thanks to everyone who look at this. I think i have a solution. I don't like it.
I can use a machine word for ordinary pointers, and 4 machine words for a pointer to a compact linear type. The only problem is that at present the compact linear type 2 is identical to C bool. I have to make them distinct. This is the only type affected. The current model is wrong anyhow since a compact linear type is 64 bits and a C++ bool is a single byte.
This change will break some code. But that's better than an unsound type system.
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https://www.neetprep.com/question/26392-first-order-reaction-complete---minutes-time-iscompleted--its-original-amount--min--min--min--min/54-Chemistry--Chemical-Kinetics/662-Chemical-Kinetics
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# NEET Chemistry Chemical Kinetics Questions Solved
A first order reaction complete 40% in 20 minutes. In how much time it is completed 90% of its original amount?
1. 45 min
2. 60 min
3. 75 min
4. 90 min
(4) K = (2.303/t)log(a/a-x)
when x = (40/100)a = 0.4a
t = 20min
$\therefore$ K = (2.303/20)log(a/a-0.4a)
=(2.303/20)log1/0.6
K = 0.02554 min-1
t = (2.303/0.02554)log(a/a-0.9a)
=2.303/0.02554 log (1/0.1)
=90.17 min
Difficulty Level:
• 35%
• 18%
• 20%
• 29%
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https://dwwiki.mooo.com/wiki/Khin-bin-lap
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Lip-bibh-khin & Khin-bin-lap
(Redirected from Khin-bin-lap)
Lip-bibh-khin and Khin-bin-lap live inside the Djelibeybi witch caravan, a camel-powered mobile home.
Lip-bibh-khin
A former advisor to the Pharaoh and a younger version of her sister, she has aged well in the climate of Djelibeybi, despite the harshness of the desert. She is tall and somewhat overbearing but in spite of herself, is always nice to others.
She is in good shape.
She is standing.
You can't help but notice fifty-two warts upon her face.
Wearing : a black samite robe and a silver bracelet.
Lip-bibh-khin used to tell fortunes to the Pharaoh. Maybe she can tell yours?
Khin-bin-lap
One of the former advisors to the Pharaoh, she looks very wise. Her weathered skin and wrinkles indicate many hours in the hot Djelian sun.
She is in good shape.
She is standing.
You can't help but notice seventy-one warts upon her face.
Wearing : a long dark cloak and a gold ring.
• Khin-bin-lap can provide young witches with a taliswoman to take them to and from Bad Ass.
• She can provide gender reassignment for males wishing to join the witches guild.
• Khin-bin-lap teaches the squinching squint method.
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http://www.cs.auckland.ac.nz/~j-hamer/07.363/prolog-for-se.html
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# Prolog for Software Engineering
A tutorial by Peter B. Reintjes for the 1994 International Conference on the Practical Applications of Prolog
Originally presented at the Royal Society of Arts, London on April 27, 1994.
The Prolog programming language offers several opportunities to tackle the fundamental problems of software engineering. By properly exploiting certain characteristics of Prolog, we can improve the clarity, robustness, and reliability of programs as well as improving communication between programmers.
But clear, reliable, and maintainable programs do not write themselves, even in Prolog. Therefore, this tutorial will focus on systematic development of small Prolog programs, the role of specifications, how to build interfaces to other languages and systems, standardized programming techniques and styles, approaches to performance measurement to increase efficiency, how to effectively rewrite for efficiency, and how to produce documentation in a literate programming style.
Finally, there will be a description of a performance monitor and a tool for handling formal languages in Prolog.
# Some Major Problems
• Too much code. Either tens of thousands, or hundreds of thousands, or millions of lines of code for an Application''.
• No one really understands exactly what the code is doing.
• There is insufficient documentation. In fact, it is so unusual to have documentation, it is ignored when it does exist.
• We have little chance of ever understanding all of the interactions between different parts of a large system.
• The people who do have a chance of understanding the code, very often don't understand the application.
• People do not reuse existing software either because they don't trust it or because it is not general enough.
All of these problems can be related to the fact that too many programs are written in languages which describe operations at too low a level. In other words, the expressibility of the programming language is far below the level of a natural description of the problem.
Programs dealing with human-scale problems should be written in some unambiguous subset of natural language such as predicate calculus, or at the very least, Prolog rather than C or C++.
The paralyzing dictum that We cannot afford to re-write the code'' is likely to prove false. There are many indications that we will soon be unable to afford the maintainence of old code.
# Rewrite, Rewrite, REWRITE!
## Traditional Model of Software Development
Specify => Build => Test => Tune
This model of software development assumes that you know exactly what you want to build.
In this model the entropy (amount of disorder in the software) only increases over the lifetime of the program.
When an artifact is too large and complex for a person to understand, adding features and fixing bugs consists of adding code and new pathways through existing code. The integrity of the program always suffers.
Uncertainty about the complete function of a piece of software forces the maintenance worker to frequently add, but almost never remove code.
The Evolutionary Model of Software Development
Steps (in no particular order) are:
• Data-structure Analysis
• Prototyping
• Refinement
• Tuning
Organisms resist entropy by constantly re-building. Any organism that repaired itself by building new structures, without removing existing structure would die of self-poisoning. However, constant rewriting is often infeasable, since programs would more often be broken more often than working in development.
## Punctuated Equillibrium: A Model
Stephen Jay Gould, the paleontologist, has proposed the theory of Puncutated Equllibrium which says that evolution does not always proceed smoothly with gradual changes, but that periods of gradual change are interrupted by very short-term upheavals which result in massive die-offs of large numbers of species.
For our purposes we might use the considerably less apocalyptic metaphor of Spring Cleaning''. We must be willing to periodically rip up and make major changes to our software, but without concise, high-level languages such as Prolog, such upheavals are nearly impossible.
## The Gospel According to O'Keefe
By far the best book on Prolog Programming style is The Craft of Prolog by Richard A. O'Keefe.
This book is an absolute requirement for any serious Prolog programmer. There are many important things here that no other Prolog books even mention.
# Using Prolog
## The Program Equation
When we consider Kowalski's concise equation:
Algorithm = Logic + Control
It is easy to forget about the original equation from which it derives. Namely:
Programs = Algorithms + Data Structures
With the result that our programs seem to be dominated by list-traversal predicates of the form:
map([], []).
map([Item|Items], [X|Xs]) :-
predicate(Item, X),
map(Items, Xs).
To refocus our attention on real programs rather than just algorithms, we must substitute for Algorithm in the second equation to remind us that:
Programs = Logic + Control + Data Structures
## Features of (Pure) Prolog
• Unification
• Backtracking
• Memory Management
• Pattern matching (Indexing)
• Meta-programming,
• Low procedure-call overhead.
## Temptations of (Impure) Prolog
• Meta-logical tests (var/1, nonvar/1)
• Database operations (assert/1, retract/1)
• Cuts!
• If-then-else structures.
Extensive use of the impure features is a strong indication that something is wrong with your program.
## Arguments: Boon or Bane?
Many people complain about the lack of global variables in Prolog because they have to write predicates with ten or twenty arguments. If you have this problem, either This relationship between twenty things is an important aspect of your application (unlikely).
You have not defined your data structures and relations properly (very likely).
In the rare event of case #1, you must keep, cherish, and document the twenty arguments since they represent an important and probably extremely subtle characteristic of your application.
If you are complaining because you find yourself adding two arguments one minute, and later deleting another argument or moving the fifteenth argument to the third place, the problem is not that of a large arity relationship, but poor program organization. You must appreciate an argument when it means something, and recognize when they are the result of poor design. Very rarely will you fruitfully replace an argument with a global assertion, though the temptation will be strong.
Turn away from the Dark Side, Luke - Obi Wan Kenobe
## Efficient Data Structures: How Many Bits Do You Use?
Bruce Smith, who taught me Prolog programming in 1986 once commented on the following fragment of a program I had written.
display_list([]).
display_list([Item|Items]) :-
display_item(Item),
display_list(Items).
display(graphic(Object, Color)) :-
set_color(Color),
draw_object(Object).
display(text(X, Y, Text)) :-
set_color(black),
name(Text, Chars),
write_chars(X, Y, Chars).
He pointed out that I was only using one bit of the atoms graphic and text. In fact, if the display/1 predicate had eight clauses, for the eight different objects that ultimately had to display (transistors, wires, etc.), at least I would be using three bits.
If we want to manipulate arrays of zeros, ones, and x (don't care) values, the obvious data-structure might be a list-of-lists (we will use this later in the circuit minimization example).
[[1,0,x,1,0],
[0,x,x,0,x],
[1,x,x,0,x],
[x,1,1,1,x],
[x,1,x,x,1]]
But while each of the twenty-five elements represent an information content of two-bits, Prolog uses 85 words (2720 bits on a 32-bit machine), rather than 50 bits.
If the row width is fixed (and less than 256) we can use row(1,0,x,1,0) to represent a rows and reduce this to 40 words, or 1280 bits. If the columns are fixed we can reduce the outer list overhead to 6 rather than 10, for a total of 1152 bits.
In the limit as the array gets larger our structure will use 1/3 of the space required by the naive list-of-lists.
But we have not even looked at the amount of space required for each two-bit data element. We need a way to use more of the bits in each integer. Now, in this particular application, the matrices are quite sparse, with many X or don't care'' elements. If we want to take advantage of the sparsity, we must have a way for each element to carry its column number (since all columns will not appear in the representation), and this directly suggests how to use more of the bits in the 32-bit integers that hold our data elements.
Operationally, we encode an element by left-shifting a variable's column index sufficiently to store its value into the lower bits. For boolean values we only shift the index one bit position. Thus a 4 represents a 0 at position 2 ( (2>>1) OR 0 => 4).
X1 X2 X3 X4 -> X1 X2 X3 X4
2 0 1 2 4 7
0 0 2 2 2 4
1 2 2 1 3 13
2 2 2 2
## Original Matrix and Encoding
The lesson is: Don't be afraid to twiddle bits in Prolog. (But of course, neither should you do it unnecessarily.)
# Literate Programming
We really must take advantage of the conciseness of Prolog by writing readable programs. Self-documenting'' programs are a myth. There is no substitute for having clear, concise prose accompany an algorithm.
This is particularly worthwhile because well-written Prolog programs can serve as formal definitions of our applications and not simply as implementions. A logically cohesive description of an application will transcend a particular implementation and will ultimately be of much greater value.
Good mathematical descriptions have lifetimes measured in centuries. As programs become more like formal specifications of the problems they address, and less like collections of imperative code to handle special cases, their potential lifetimes may approach those of mathematical theorems.
## Integrated Documentation
I use the following scheme in which documents are built directly from Prolog source code, since the need to edit and consult the program is more frequent than the need to produce the documentation.
/**
Incisive text in LaTex
(or another suitable markup language).
**/
meaningful_predicate(WellNamed, Arguments) :-
well_chosen_word(Arguments, WellNamed).
/**
Riveting revelation about the above code...
**/
This is run through a filter (src2tex) to become:
Incisive text in LaTex (or another suitable markup language).
\begin{verbatim}
meaningful_predicate(WellNamed, Arguments) :-
well_chosen_word(Arguments, WellNamed).
\end{verbatim}
Riveting revelation about the above code...
## The Elements of Prolog Style
Well-constructed Prolog programs can have declarative and procedural readings which are very close to a natural language specification. Combined with the reduction in the size of source code, we have an opportunity to radically change the presentation of programs.
All programming languages have an interpretation in natural language, but if we examine the rules for good prose style, they can be considered as rules for good Prolog programming. This is true to an extent that is not true in other languages. These rules are taken from The Elements of Style with code'', clause'' and predicate'' substituted for words'', sentence'' and paragraph''.
• Revise and Rewrite
• Omit needless code
• Keep related code together
• Put statements in positive form
• Choose a suitable design and hold to it
• Make a predicate the unit of composition
• Express co-ordinate ideas in similar form
• Work with nouns and verbs
• Use orthodox spelling
• Be clear
• Prefer the standard to the offbeat
• Do not take shortcuts at the cost of clarity
One reason for this closeness between the values of good writing and good Prolog programming is the correspondence between clarity and efficiency that Prolog exhibits. It is more difficult to forsee improved software engineering in other languages where clarity and efficiency are more often at odds.
# Software Engineering Case Studies
## Blackbox and Whitebox Reusability
After maintainability, re-usability of code is an important goal of good Software Engineering. In the case studies which follow, we will pay particular attention to the two kinds of software reusability known as BLACKBOX and WHITEBOX reusability.
BLACKBOX reusability is the kind of reusability you get from a good tool. You can use it without knowing or caring about how it is implemented.
WHITEBOX reusability is the the sort that you can get from a source-code library, where a particular algorithm might be picked up in source code form.
Clearly BLACKBOX reusability comes about when the software has implemented a function of very general applicability. Good examples are, the C library, the standard SmallTalk methods, Prolog's term-expansion feature, and the UNIX LEX and YACC utilities.
WHITEBOX reusability depends crucially on the readability of code, which we believe is a particular strength of Prolog.
Case Study #1 has WHITEBOX and BLACKBOX characteristics.
L'Express: A Logical version of Espresso
A popular and important algorithm for the minimization of logic functions known as Espresso has been defined almost entirely in terms of matrix operations of an algebra of five values. Espresso is well established as the industry standard of two-level logic minimization technology. This algorithm is described in detail in Logic Minimization Algorithms for VLSI Synthesis by Brayton et al. (Kluwer Academic Press, 1984).
The space and time limitations of logic minimization problems coincide with large, but sparse, matrices. A direct implementation of this algorithm, in any language, is less than optimal if one does not take advantage of the sparsity of large logic function arrays. A sparse-matrix approach directly alleviates the space problem and may improve the time performance.
This chapter describes a logical'' version of Espresso. This program is not yet complete but describes the basic structure and pieces of the fundamental algorithms.
The primary motivations for developing this example are:
• Software Engineering: The Prolog definitions of these algorithms are nearly as compact as the original pseudo-code.
• Prototyping/Research: Since the Prolog description is compact and clearly defines the logic of the algorithms, it is more ammenable to experimentation and improvement.
• Education: We demonstrate how an efficient implementation can be developed for an algorithm considered by many to be inappropriate for Prolog. In finding an efficient Prolog implementation for Espresso, we have established a general method for constructing efficient Prolog programs for sparse-matrix operations over finite algebras.
The Espresso Algorithm
Espresso-II is a widely used algorithm for the minimization of logic circuits in VLSI design.
The N-column matrix of boolean values (including don't cares) represents the function of N variables for which our combinatorial circuit must produce a true output. Each column translates directly into a network of inverters and AND gates with the number of inputs equal to the number of elements with 0 and 1 values. Each row corresponds to the input of an OR-gate in the final circuit.
Espresso uses a set of powerful heuristics to reduce these matrices to find the minimal circuit design for that function.
Briefly, there are three steps in each iteration of the minimization process, but a non-changing cost after any step directs the algorithm to enter the LAST_GASP phase which may move the current solution out of a local minimum.
The main, three-step, reduction algorithm is then re-tried until no minimization is possible in either the inner or by trying LAST_GASP.
The Espresso-II Algorithm, from page 56 of Logic Minimization Algorithms for VLSI Synthesis, by Brayton et. al., Kluwer Academic Publishers, 1984.
Procedure ESPRESSO-II (F, D)
/* Given F, a cover of {f,d,r} = (on-set, don't-care, off-set)
/* and D a cover of d, minimizes Phi(F)=(NPT,NLI,NLO)
/* where NPT is the number of cubes, NLI is the number of
/* input literals and NLO is the number of output literals.
/* Returns a minimized cover F and its cost Phi.
Begin
F <= UNWRAP(F)
R <= COMPLEMENT(F, D)
Phi1 <= Phi2 <= Phi3 <= Phi4 <= COST(F) /* Initialize Cost
LOOP1: (Phi,F) <= EXPAND(F,R) /* F is prime and SCC-minimal
if (First-Pass) /* Move essential primes
(Phi,F,D,E) <= ESSENTIAL_PRIMES(F,D)/* into don't care set
if (Phi == Phi1) goto OUT /* Check termination criterion
Phi1 <= Phi$(Phi, F) <= IRREDUNDANT_COVER(F,D) /* F is minimal cover if(Phi == Phi2) goto OUT /* of prime implicants Phi2 <= Phi LOOP2: (Phi,F) <= REDUCE(F,D) /* Each cube of F replaced by if (Phi == Phi3) goto OUT /* smallest cube containing Phi3 <= Phi /* its essential'' vertices. goto LOOP1 OUT: if (Phi == Phi4) goto QUIT (Phi', F) <= LAST_GASP(F, D, R) /* If no further improvement if (Phi == Phi') goto QUIT /* terminate Phi1 <= Phi2 <= Phi3 <= Phi4 <= Phi' goto LOOP2 QUIT: F <= union(F,E) /* Put essential primes E back D <= D - E /* into cover and out of D (Phi, F) <= MAKE_SPARSE(F,D,R) /* Concentrate on literals return(Phi, F) End ## Espresso-II in Prolog Global data and seven Go-tos may leave us wondering about correctness and termination. We can hide the (now local) state with DCGs. costs(Phi1, Phi2, Phi3, Phi4)-pla(F,R,D,E) Where each Phi is a cost(#ProductTerms, #Inputs, #Outputs) term and the call to lexpress/2 is simply: lexpress(_-pla(F,_,D,_)), costs(_,_,_,Phi(min))-pla(Fm,_,_,_) lexpress --> unwrap, complement, init_cost, expand, essential_primes, iterate, add_to_care, sub_from_dont_care, make_sparse. iterate --> irredundant, ( cost_changed(1) -> reduction ; out). reduction --> reduce, ( cost_changed(2) -> expansion ; out). expansion --> expand, ( cost_changed(3) -> iterate ; out). out --> ( cost_changed(4) -> last_gasp ; {true}). last_gasp -> reduce2, ( cost_changed(4) -> init_cost, iterate ; {true}). Note: The actual code is smaller and clearer than the pseudo-code, but we're not happy with the use of if-then-else. Espresso-II in Prolog (again) lexpress --> unwrap, complement, init_cost, expand, essential_primes, iterate, add_to_care, sub_from_dont_care, make_sparse. iterate --> irredundant, ( decrease(irredundant) -> reduce, ( decrease(reduce) -> expand, ( decrease(expand) -> iterate ; out ) ; out ) ; out ). out --> ( decrease(global) -> reduce2, ( decrease(global) -> init_cost, iterate ; {true} ) ; {true} ). This more clearly shows the three-step inner loop and the two-step outer loop, but the if-then-elses are worse than ever. ## Cost Computations decrease(reduce, costs(I,R,E,G)-P,costs(N,R,E,G)-P) :- newcost(P,I,N). decrease(expand, costs(I,R,E,G)-P,costs(I,N,E,G)-P) :- newcost(P,R,N). decrease(irredundant, costs(I,R,E,G)-P,costs(I,R,N,G)-P) :- newcost(P,E,N). decrease(global, costs(I,R,E,G)-P,costs(I,R,E,N)-P) :- newcost(P,G,N). sum_costs(pla(F,_,_,_), Old, cost(NP, NI, NO)) :- sum_costs(PLA, 0, NP, 0, NI, 0, NO), cost(NP, NI, NO) @< Old. sum_costs([], P, P, In, In, Out, Out). sum_costs([c(Input,Output)|Cs],P0,P,In0,In,Out0,Out) :- P1 is P0 + 1, length(Input, LI), In1 is LI + In0, length(Output,LO), Out1 is LO + 0ut0, sum_costs(Cs, P1, P, In1, In, Out1, Out). Espresso-II in Prolog (yet again) lexpress --> unwrap, complement, init_cost, expand, essential_primes, iterate, add_to_care, sub_from_dont_care, make_sparse. iterate(done) --> []. iterate(Step) --> step(Step), change_cost(Step, Next), iterate(Next). step(reduce) --> reduce. step(expand) --> expand. step(irredundant) --> irredundant. step(iterate) --> init_cost, irredundant. step(reduce2) --> reduce2. change_cost(reduce, expand) --> decrease(reduce), !. change_cost(expand, irredundant) --> decrease(expand), !. change_cost(irredundant,reduce) --> decrease(irredundant), !. change_cost(iterate, reduce) --> decrease(global), !. change_cost(reduce2, iterate) --> decrease(global), !. change_cost(reduce2, done) --> [], !. change_cost( _, reduce2) --> []. The termination of iterate//1 is now a little clearer, but we've gotten rid of the if-then-elses only to have a bunch of cuts (This is an obvious result when you consider how an if-then-else acts behaves like a local cut). ## Espresso-II in Prolog (finally) lexpress --> unwrap, complement, expand, essential_primes, init_cost, iterate, dd_to_care, sub_from_dont_care, make_sparse. iterate(done) --> []. iterate(Step) --> step(Step, Continue, Stop), check_cost(Step, CostChange), next_step(CostChange, Continue, Stop, Next), iterate(Next). % step(CurrentStep, ContinueStep, StopStep) --> current_step. step(irredundant, reduce, reduce2) --> irredundant. step(reduce, expand, reduce2) --> reduce. step(expand, irredundant, reduce2) --> expand. step(reduce2, iterate, done) --> reduce2. step(iterate, reduce, done) --> init_cost, irredundant. check_cost(Step, CostChange) :- cost_value(Step, Previous, cost(NP, NI, NO), PLA), { sum_costs(PLA, cost(0, 0, 0), NewCost), compare(CostChange, Previous, NewCost) }. next_step(=, Stop, _, Stop) --> []. next_step(<, _, Cont, Cont) --> []. next_step(>, _, Cont, Cont) --> []. The five-step process (three inner and two outer) is represented as a state table, clearly showing the continuation and termination states. No cuts or if-then-elses! Cost Computations % cost_value(+Step, -Previous, -New, -PLA, +DataIn, -DataOut) cost_value(reduce, I, N, P, costs(I,R,E,G)-P,costs(N,R,E,G)-P). cost_value(expand, R, N, P, costs(I,R,E,G)-P,costs(I,N,E,G)-P). cost_value(irredundant,E, N, P, costs(I,R,E,G)-P,costs(I,R,N,G)-P). cost_value(iterate, G, N, P, costs(I,R,E,G)-P,costs(I,R,E,N)-P). cost_value(reduce2, G, N, P, costs(I,R,E,G)-P,costs(I,R,E,N)-P). sum_costs([], Cost, Cost). sum_costs([c(Input,Output)|Cs], cost(P0,In0,Out0), Cost). length(Input, LI), length(Output,LO), P1 is P0 + 1, In1 is LI + In0, Out1 is LO + 0ut0, sum_costs(Cs, cost(P1,In1,Out1), Cost). Prolog is able to abstract and clarify fragments of code at the very lowest levels of the algorithm as well as the highest. Some of the operations in this algorithm are trivial in Prolog. The predicate add_to_care//0 computes the union of the logic function cover and the essential prime factors. What sounds like a complex and subtle computation turns out to be append/3 in the representation we have chosen. add_to_care(C-pla(F0,R,D,E),C-pla(F,R,D,E)) :- append(F0, E, F). And the cost initializer seen before is easily defined in terms of the sum_costs/7 predicate we have just seen. init_cost(_-PLA, costs(C,C,C,C)-PLA) :- sum_costs(PLA, 0, NP, 0, NI, 0, NO), C = cost(NP, NI, NO). More generally, Espresso computations involve things like measuring the Hamming distance between two rows (cubes'' in boolean N-space), and computing intersections. Cube Consensus consensus(C, D, Consensus) :- distance(C, D, In, Out), consensus1(In, Out, C, D, Consensus). consensus1(0, 0, C, D, Consensus) :- cube_intersect(C, D, Consensus). consensus1(1, 0, C, D, Consensus) :- raised_intersection(C, D, Consensus). consensus1(0, 1, C, D, Consensus) :- lower_outputs(C, D, Consensus). Here we justify the use of if-then-else because in simple arithmetic tests, the creation of choice points can be completely avoided. Co-Factors of a single cube. An example of the most fundamental of the low-level operations is the computation of the Shannon co-factor of a matrix, relative to a particular positive or negative variable. The computation of the co-factor corresponds to the following definition from [Brayton84] (They used 3 and 4 for the 0s and 1s in the output terms). When the Factor p is just a single coordinate, this becomes: co_cover([],_,[]). co_cover([C|Cs],P,[X|Xs]) :- cofactor(C,P,X), !, co_cover(Cs,P,Xs). co_cover([_|Cs],P,Xs) :- co_cover(Cs,P,Xs). cofactor([],_,[]). cofactor([C|Cs],P,Xs) :- ( C =:= P -> Xs = Cs ; C>>1 > P>>1 -> Xs = [C|Cs] ; C>>1 < P>>1 -> Xs = [C|X1s], cofactor(Cs,P,X1s) ). Shannon Co-Factors of a Cover'' Our cover'' for a function is the entire matrix, where each row is a cube'' in the space of the boolean variables. We frequently need to compute both positive and negative Shannon co-factors of the entire matrix. cofactors(Cover,Var,C1,C0) :- V1 is Var<<1 / 1, V0 is Var<<1 / 0, co_cover(Cover,V1,C1), co_cover(Cover,V0,C0). And a more general version of the cofactor routine is provided to accept arbitrary cubes, rather than a single variable. gen_cofactor([],_,[]) :- !. gen_cofactor(_,[],[]) :- !. gen_cofactor([C|Cs],[F|Fs],Xs) :- ( C>>1 > F>>1 -> evaluate(default,F,X), gen_cofactor(Cs,F,X1s) ; C>>1 < F>>1 -> Xs = [C|X1s], gen_cofactor(Cs,F,X1s) ; evaluate(C,F,X) -> Xs = [X|X1s], gen_cofactor(Cs,F,X1s) ; gen_cofactor(Cs,Fs,Xs) ). The purpose of this is not to dazzle you with terminology and algorithms from the world of logic minimization, but to show how we can create an (efficient) implementation which is still very close to a mathematical description of the problem. Once you understand the matrix encoding, there is very little implementation detail to stand in the way of understanding the algorithm. This implementation of Expresso is described in less than 1000 lines of Prolog code, compared with 11,000 lines of C code. End of Case Study #1 ## Lessons from L'EXPRESS Development • Bit-twiddling in Prolog is okay -- but there must be a real benefit. In particular, if it is bits'' that the application is talking about, then it is bits'' we want to see in the implementation. • Good Logic programs are state machines without state, or rather where the state is a parameter that is passed along with the point of computation. This can be done invisibly with DCG's. If you use global state then you are not really using Prolog. • Asserts and retracts are generally not okay. Except maybe in a first draft. It may be okay to be a bit lazy while prototyping, but if you let it go on to long, and you begin to feel that you have an investement'' in the poorly written code, then of course you will be correct. But it will be a bad investement. • Prolog re-implementations of C programs require between$1over 10$and$1over 20$as much source code, and are much easier to understand. This translates to between$1over 100$and$1over 400$as much maintenance effort. • If your code contains too much punctuation (e.g. !), it may become extinct the next time the Equilibrium is Punctuated''. It is quite common for a program which simulates the imperative style by using database changes to run twenty to thirty times faster when rewritten to use pure data structures. - Richard A. O'Keefe in The Craft of Prolog # Case Study #2: BLACKBOX reusability ## MULTI/PLEX: A Tool for Formal Languages Wouldn't it be great if we could read and write logical forms of all formal languages as easily as we can read/1 and write/1 Prolog clauses. Furthermore, suppose we could avoid writing the readers and writers for all the (formal) languages in the world and good get both input and output functionality from a single, declarative representation of each language's grammar. MULTI/PLEX is a combination of two general-purpose tools which, when combined, result in a language-independent translation system. The first tool is a long-overdue version of the UNIX lex [Lesk75] program for Prolog. It is tempting, though misleading, to describe the second tool as the Prolog counterpart of YACC [Johnson78] program. The obvious objection that Prolog has little need for a parser generator is answered by pointing out a few additional features. From a single BNF-style specification of a language, MULTI creates both a parser and a pretty-printer. Furthermore, parser/generators can be constructed from the textual user specifications at run time, avoiding intermediate compilation steps. By combining these tools in the program MULTI/PLEX, a language-independent translator is created which is driven only by the information in the user-provided language specification files. The three goals of this work can be summed up as: • Add a LEX-like tool to the Prolog development environment (PLEX). • Provide automatic transformation of a single grammatical description of a language into a parser and a pretty-printer (MULTI). • Develop a translation system which can operate from external high-level descriptions of the languages involved. # The MULTI/PLEX Program Prolog can be at its best when used to manipulate formal languages, but with so many languages around, we will be spending a lot of time writing parsers and pretty-printers. We begin by describing a complete application, consisting of only 12 lines of code, which uses the MULTI/PLEX module as a black box. This program constructs and then executes a translator for a pair of formal languages. The specifications (grammars) for these languages must construct identical parse-trees for this naive form of MULTI/PLEX to work correctly. The input to this program consists of high-level specifications which define the lexical and syntactical structure of the languages involved. The seven phases of MULTI/PLEX • Consult specification and construct Parser • Construct a Tokenizer • Execute the Tokenizer • Execute the Parser • Consult specification and construct Printer • Execute the Printer # The MULTI/PLEX Translator :- use_module(multi). % includes plex main(InFile, OutFile) :- name_relation(InFile, Spec, Lexer, Parser, _), consult(Spec), % CREATES PARSER AND TOKENIZER see(Input), get_file(Chars), call(Lexer, Chars, Tokens), call(Parser, Data, Tokens, []), %%%% RECONCILE DIFFERENCES BETWEEN PARSE-TREES name_relation(OutFile, OutSpec, _, _, Printer), consult(OutSpec), % THIS CREATES THE PRINTER call(Printer, Data, OutChars, []), write_list(OutChars, 0). ## Prolog Tokenizers: The Problem It is quite easy to write tokenizers in Prolog by following O'Keefe's recipe for defining simple finite-automata [OKeefe90]. However, this technique has two drawbacks. One, it is a repetitive task which must be re-verified (at least partially) for each new tokenizer that is created. Two, many of the predicates require cuts to remove unnecessary choice points or have lengthy if-then-else chains to distinguish characters. If we were to write 128 clauses for every transition, deterministically indexing on the entire ASCII character set, we would avoid the creation of choice points and eliminate the need for cuts or if-then-else constructs. Unfortunately, manually writing 128 clauses for each character class is tedious to the point of being impractical. ## Prolog Tokenizers: The Solution A PLEX specification defines patterns, goals to call when the pattern has been recognized and a term representing the object to be passed back. If the atom text appears in a goal, it will be replaced by the list of characters matching the pattern (like yytext in LEX). lang lexicon "[ tn]+" is []; "begin" is begin ; "end" is end ; "." is '.'; ";" is ';'; "*" is '*'; "+" is '+'; "-" is '-'; "[0-9]+" is integer(N) if name(N,text); "[0-9]+.[0-9]+([eE][+-]?[0-9]+)?" is float(F) if name(F,text); "[a-zA-Z_][a-zA-Z_0-9]*" is identifier(N) if name(N,text). ## Using Term Expansion I did not want to solve the Tower of Babel'' problem by defining a new language, so I used Prolog term_expansion/2 to define a dialect of Prolog for lexical and BNF specifications. Although I use a few operator definitions, I strongly advice novice programmers to guard againts Operatitis, the disease of defining operators to make Prolog programs more like natural language. Adding operators for cosmetic reasons will make your code less readable by Prolog programmers. term_expansion(lexicon(Lang,Rules),Module:Clauses):- ( plex:plex(Lang, Rules, Lexer) -> true ; user:message_hook('Lexicon error'(Lang), _, _) ), Clauses = [(:-no_style_check(discontiguous))|Lexer], strings:concat_atom([Lang,'_parse'], Module), Compile = Module:Clauses. term_expansion((A::=B), Clauses) :- ( multi:multiplex_expansion(A, B, Clauses) -> true ; user:message_hook('Syntax error in BNF'(Lang),_,_) ), ## Operators/Data Structures Code to call rule compiler and establish goals to be called in the acceptor state. setup_rules(X is Result if Goal, In, Out) :- rule(Classes,[end(Goal,Result)], X, []), append(Classes, Out, In). setup_rules(X is Result, In, Out) :- rule(Classes,[end(true,Result)], X, []), append(Classes, Out, In). setup_rules((R;Rs)) --> setup_rules(R), setup_rules(Rs). ## Intermediate Forms "[0-9]+" is integer(N) if name(N,text); is turned into: class("0123456789",+,[end(name(N,text),integer(N))]) and when converted to primitive classes this will be: class("0123456789",one, [class("0123456789",*, [end(name(N,text), integer(N))]) ]) ## Finite-State Automata for Recognizing Tokens Current(C,[C2|Cs],[C|T],Text,Token,Rest) :- % On Set Next(C2, Cs, T, Text, Token, Rest). Current(C, Cs, Accum, Text, Token, Rest) :- % Off Set Next(C, Cs, Accum, Text, Token, Rest). Accept(C, Cs, [], Text, Token, [C|Cs]) :- Goal. It is interesting to see this obvious and natural application of a state-transition design after struggling at length with a very different application and finally arriving at a simple state-transition model. Next time, perhaps we should start by writing down the state-transition model for the program rather than random'' psuedo-code. ## MULTI: Bi-Directional Grammars xyz_file := [ library, Name ], cells, update(type,library), update(name,Name). cell := [ Type, '(' ], arguments(Params), down(Name), update(parameters,Params), [ begin, Name ], newline, indent, statements, undent, [ end ], optional([Name]), [';'], newline, up. statements := value_attribute, newline, statements. statements := cell, newline, statements. statements := []. ## Bi-Directional Grammars (cont.) value_attribute := [ Name, '=' ], value(V), [ ';' ], newline, update(Name, V). value(Vs) := [ '(' ], arguments(Vs). value(V) := [ V ]. arguments([]) := [ ')' ]. arguments(V) := [ V, ')']. arguments([V|Vs]) := [ V ], more_values(Vs). End of Case Study #2 ## Lessons from MULTI/PLEX • Prolog is the almost certainly the best programming language for manipulating languages. • The largest productivity gains have always come the development of good representations, whether this is a data structure or a language. • Prolog re-implementations of C programs require between 1/10 and 1/20 as much source code, and are much easier to understand. This translates to between 1/100 and 1/400 as much maintenance effort. • Isn't it great now that we can read and write logical forms of all languages (almost) as easily as we can read/1 and write/1 Prolog clauses. Point of view is worth 80 IQ points. -Alan Kay ## Application Composition and Decomposition An interesting thing about the two (fairly large) software projects examined is that there is no apparent connection between them. This is good, since it makes it more likely that they can be combined into a larger program. The data-structures that these two programs must share appear in the L'EXPRESS source code and the language specifications which are independent of the MULTI/PLEX code. Learn to think about the components of large applications as tools and think of existing tools as potential components of a large application. We can compose elements like this to get extremely powerful programs with excellent maintainability (Both L'Express and MULTI/PLEX exist as a stand-alone programs and as library modules). Compose Programs for functionality De-Compose for Maintenance it (Re-Writing) ## Multi-Lingual Logic Synthesis runtime_entry(start) :- unix(argv(CmdLine)), assert(type(fd)), /* default */ options(CmdLine, File), multplex_input(File, PLA0), type(Type), compute_other(Type, PLA0, PLA1), lexpress(_-PLA1, costs(_,_,_,Cost)-PLAMin), format(user_error,"Final PLA cost:~q~n",[Cost]), change_suffix(File, '.po', OutFile), multiplex_output(OutFile, PLAMin). options([], _). options([Op|Ops], File) :- option(Op, Ops, Rest), !, option(Rest, File). options([File|Ops], File) :- option(Ops, _). option('-Decho', T, T) :- assert(echo). option('-eness', T, T) :- assert(ness). option('-t', [Type|T], T) :- retract(type(_)), assert(type(Type)). ## Main Routine for L'Express (again) runtime_entry(start) :- unix(argv(CmdLine)), options(CmdLine, File, fd, InType), multplex_input(File, PLA0), compute_other(InType, PLA0, PLA1), lexpress(_-PLA1, costs(_,_,_,Cost)-PLAMin), format(user_error,"Final PLA cost:~q~n",[Cost]), change_suffix(File, '.po', OutFile), multiplex_output(OutFile, PLAMin). options([], _) --> []. options([Op|Ops], File) --> option(Op, Ops, Rest), !, option(Rest, File). options([File|Ops], File) --> option(Ops, File). option('-Decho', R, R) --> {assert(echo)}. option('-eness', R, R) --> {assert(ness)}. option('-t', [Type|R],R, _, Type). # Performance Monitoring ## A Poor Man's Profiler The best performance monitors are those that are built into Prolog Systems. However, here is another way to measure the system resources used by a particular call. :- op(900, fx, '$').
$G :- init_measure(G), ( G ; finish_measure(G), fail ), backtrack_measure(G), finish_measure(G). backtrack_measure(_). backtract_measure(G) :- init_measure(G), fail. init_measure(G) :- initial_values(G, Values), findall(stat(Type,Value), (statistic_type(Type,_), get_statistics(Type, Value)), Before), assert(measurement(G, Values, Before). initial_values(G, Values) :- retract(measurement(G, Values,_), !. initial_values(G, Values) :- findall(stat(Type,0), statistic_type(Type,_), Values). finish_measure(G) :- findall(stat(Type,Value), (statistic_type(Type,_), get_statistics(Type, Value)), After), retract(measurement(G, SoFar, Before). combine_statistics(Before, After, SoFar, Total), assert(measurement(G, Total, After)). combine_statistics([], [], [], []). combine_statistics([A|As],[B|Bs],[P|Ps],[T|Ts]) :- combine_statistic(A, B, P, T), combine_statistics(As, Bs, Ps, Ts). combine_statistic(stat(T,Before), stat(T,After), stat(T,Prev), stat(T, Total)) :- statistic_type(T, Op), combine(Op, Before, After, Prev, Total). combine(add, Before, After, Prev, Total) :- Total is Prev + (After - Before). combine(max, _, After, Prev, Total) :- compare(Op, After, Prev), maximum(Op, After, Prev, Total). maximum(<, A, B, B). maximum(=, A, _, A). maximum(>, A, _, A). statistic_type(runtime, add). statistic_type(global_stack, max). statistic_type(memory, max). statistic_type(local_stack, max). statistic_type(trail, max). statistic_type(garbage_collection, add). get_statistic(runtime, Value) :- statistics(runtime, [_,Value]), !. get_statistic(_, Value) :- statistics(runtime, [Value|_]). program :-$ work(X),
write(X), nl,
\$ work(Y),
write(Y), nl.
## The Prolog Programmer Who Knew Too Much
We are going to consider how a typical Prolog programmer might spend his day. Like most Prolog programmers, ours has created a predicate which correctly specifies and performs the necessary function, and he would now like to improve its performace.
Identifying Constant Columns
An important operation in L'Express is the identification of the constant columns of a matrix. That is, any number which appears in all rows of the matrix.
constant_columns(
[[4, 9, 23, 55, 63, 107, 239],
[5, 9, 31, 55, 60, 73, 82, 99, 107],
[9, 23, 55, 107, 128, 512],
[6, 9, 13, 17, 22, 55, 63, 107 ]], CC).
CC = [ 9, 55, 107 ]
## Constant Column #1
An obvious logical formulation of this problem is simply to find those columns which are members of every row.
constant1(M,Cols) :-
findall(Col, constant(M,Col), Cols).
constant([], _).
constant([R|Rs], C) :-
member(C, R),
constant(Rs, C).
member(H,[H|_]).
member(H,[_|T]) :-
member(H,T).
## Constant Column #2
constant2([R|Rs], Cols) :-
findall(X, (member(X, R),
column(Rs, X)), Cols).
column([], _).
column([R|Rs], I) :-
item(I, R),
column(Rs, I).
item(I, [H|T]) :-
( I =:= H -> true
; I > H -> item(I, T)
).
## Constant Column #3
constant3([R|Rs], Cols) :-
constant3(R, Rs, Cols).
constant3([], _, []).
constant3([I|Is], Cs, Cols) :-
column(Cs, I),
!,
Cols = [I|Xs],
constant3(Is, Cs, Xs).
constant3([_|Is], Cs, Cols) :-
constant3(Is, Cs, Cols).
column([], _).
column([R|Rs], I) :-
item(I, R),
column(Rs, I).
item(I, [H|T]) :-
( I =:= H -> true
; I > H -> item(I, T)
).
## Constant Column #4
constant4([R|Rs], Cols) :-
constant4(Rs, R, Cols).
constant4([], Cols, Cols).
constant4([C|Cs], Ref, Cols) :-
intersect4(C, Ref, Result),
constant4(Cs, Result, Cols).
intersect4(_, [], []) :- !.
intersect4([], _, []).
intersect4([C|Cs], [P|Ps], Xs) :-
!,
(C =:= P -> Xs = [C|X1s],
intersect4(Cs,Ps,X1s)
; C > P -> intersect4([C|Cs], Ps, Xs)
; intersect4(Cs,[P|Ps], Xs)
).
## Constant Column #5
constant5([R|Rs], Cols) :-
constant5(Rs, R, Cols).
constant5([], Cols, Cols).
constant5([C|Cs], Ref, Cols) :-
intersect5(C, Ref, Result),
constant5(Cs, Result, Cols).
intersect5([C|Cs], [P|Ps], Xs) :-
!,
(C =:= P -> Xs = [C|X1s],
intersect5(Cs,Ps,X1s)
; C > P -> intersect5([C|Cs], Ps, Xs)
; intersect5(Cs,[P|Ps], Xs)
).
intersect5(_, [], []) :- !.
intersect5([], _, []).
## Constant Column #6
constant6([R|Rs], Cols) :-
constant6(Rs, R, Cols).
constant6([], Cols, Cols).
constant6([C|Cs], Ref, Cols) :-
intersect6(C, Ref, Result),
constant6(Cs, Result, Cols).
intersect6([], _, []).
intersect6([C|Cs], Ref, Result) :-
intersect6(Ref, C, Cs, Result).
intersect6([], _, _, []).
intersect6([P|Ps], C, Cs, Xs) :-
(C =:= P -> Xs = [C|X1s],
intersect6(Cs,Ps,X1s)
; C > P -> intersect6(Ps, C, Cs, Xs)
; intersect6(Cs,[P|Ps], Xs)
).
## Profile Data
In scenerio 1, there are only a few constant columns near the left side of the matrix.
constant1 687
constant2 216 constant2a 170
constant3 218 constant3a 172
constant4 105
constant5 108
constant6 126
But in scenerio 2, the rightmost column in the matrix is constant, eliminating the gains of our clever'' algorithms.
constant1 704
constant2 1030 constant2a 782
constant3 1032 constant3a 784
constant4 1427
constant5 1397
constant6 1672
Constant1 is much too expensive in scenario 1, so this is probably unacceptable, but constant2 is only twice as expensive as the best version and it is second best in scenario 2.
## Using compare/3
item(I, [H|T]) :-
( I =:= H -> true
; I > H -> item(I, T)
).
New version of item/2 using compare/3 and indexing.
item(I, [H|T]) :-
compare(Op, I, H),
item(Op, I, T).
item(=, _, _).
item(>, I, T) :-
item(I,T).
## Final version of Constant Column #2a
constant2([R|Rs], Cols) :-
findall(X, (member(X, R),
column(Rs, X)), Cols).
column([], _).
column([R|Rs], I) :-
item(I, R),
column(Rs, I).
item(I, [H|T]) :-
compare(Op, I, H),
item(Op, I, T).
item(=, _, _).
item(>, I, T) :-
item(I,T).
SICStus Profiler vs. Poor Man's
SICStus PoorMan (1000x)
constant1 687 290
constant2a 170 83
constant3a 172 75
constant4 105 47
constant5 108 45
constant6 126 39
SICStus PoorMan (1000x)
constant1 704 257
constant2a 782 371
constant3a 784 362
constant4 1427 542
constant5 1397 492
constant6 1672 520
# Summary
• Consider rewriting code at regular intervals
• Don't be afraid to twiddle bits in Prolog
• How many bits do you use...
• In Indexing
• In Data Structures
• Don't complain about too many Arguments; examine them.
• Integrate documentation with programming
• Decompose: analyze major subcomponents for generality and reusability
• Whitebox
• Blackbox
• Do Performance Measurement Last
• Eliminate cuts and if-then-elses
• Eliminate append/3 (as in non-naive reverse)
• Eliminate non-determinism; think of your program as a state-machine.
• Use DCGs instead of assert to add state'' to your program.
Peter Reintjes
Tue Sept 1 15:21:00 EDT 1994
|
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|
https://www.physicsforums.com/threads/simple-calculus-question.195299/
|
# Homework Help: Simple calculus question
1. Nov 1, 2007
### Darkiekurdo
1. The problem statement, all variables and given/known data
A reservoir of square cross-section has sides sloping at an angle of 45 degrees with the vertical. The side of the bottom is p feet in length, and water flows in the reservoir at the rate of c cubic feet per minute. Find an expression for the rate at which the surface of the water is rising at the instant its depth is h feet. Calculate this rate when p = 17, h = 4 and c = 35.
2. Relevant equations
Not stated
3. The attempt at a solution
I don't know how to begin, I'm sorry.
2. Nov 1, 2007
### Dick
Start by trying to find an expression for the volume V as a function of h and p.
3. Nov 1, 2007
### Darkiekurdo
What shape is the reservoir?
4. Nov 1, 2007
### Dick
Did you read the problem? It's a truncated pyramid with square cross section.
5. Nov 1, 2007
### Darkiekurdo
Hmm. I didn't know that. How did you come up with that?
6. Nov 1, 2007
### Dick
I read the first sentence of the problem you posted.
7. Nov 1, 2007
### d_leet
Did you even read the problem? You asked the question and it seems like you haven't even read it. The first sentence describes the shape of the resevoir.
8. Nov 1, 2007
### Darkiekurdo
Of course I read it but I didn't know what that was. Sorry.
9. Nov 1, 2007
### Darkiekurdo
Anyway, the volume of a truncated pyramid is
$$V = \frac{H}{3}(A + a + \sqrt{Aa})$$
right?
Last edited: Nov 1, 2007
10. Nov 1, 2007
### Dick
Right, if the A and a are the areas of the top and bottom.
11. Nov 1, 2007
### Darkiekurdo
What should I do next?
12. Nov 1, 2007
### Dick
Apply that formula to your problem. If the reservoir is filled to height h, what are the areas of the top and bottom?
13. Nov 1, 2007
### Darkiekurdo
So the area of A = p2 and a = (p+2h)2.
14. Nov 1, 2007
### Dick
Now you are cooking. What's the formula then for the volume V in terms of p and h?
15. Nov 1, 2007
### Darkiekurdo
Then I'll just substitute those in the formula for the volume:
$$\frac{H}{3}[p^2 + p(p + 2h) + (p + 2h)^2]$$
16. Nov 1, 2007
### Dick
H=h, right? Now to make life easier later, I would expand that out. Now you have V as a function of p and h. What next? Please don't say "I don't know".
17. Nov 1, 2007
### Darkiekurdo
Yeah, I should have written it as 1/3h instead of H/3 actually.
Thus,
$$p^2h + 2ph^2 + \frac{4}{3}h^3$$
18. Nov 1, 2007
### Dick
Better and better. What next?
19. Nov 1, 2007
### Darkiekurdo
I'm stuck. :(
20. Nov 1, 2007
### Darkiekurdo
Maybe we should take time in consideration?
|
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|
http://mathhelpforum.com/discrete-math/74615-solved-proof-equal-sum-subsets-pigeonhole-principle-print.html
|
# [SOLVED] Proof for equal sum subsets (pigeonhole principle)
• February 19th 2009, 10:11 PM
sritter27
[SOLVED] Proof for equal sum subsets (pigeonhole principle)
Let S be a set of ten distinct positive integers, all less than 107. Prove that S has two distinct subsets that both have the same sum.
So I've been racking my mind over this and I cannot figure out how to write a proper proof for it. I was thinking the pigeon hole principle might help out somehow, but I'm not entirely sure how. I'd be rather grateful to anyone who can help point me in the right direction.
• February 20th 2009, 02:28 AM
tah
Quote:
Originally Posted by sritter27
Let S be a set of ten distinct positive integers, all less than 107. Prove that S has two distinct subsets that both have the same sum.
So I've been racking my mind over this and I cannot figure out how to write a proper proof for it. I was thinking the pigeon hole principle might help out somehow, but I'm not entirely sure how. I'd be rather grateful to anyone who can help point me in the right direction.
Are you sure that it's true, does it work for any set S ? In fact if S could be partition into two sets of the same sum, then sum of S has to be even !! but take S = {1,2,3,4,5,6,7,8,9,10} and sum S is 55, so this S could not be partitioned in such a way ...
• February 20th 2009, 02:37 AM
Sum of subsets
Hello everyone
Quote:
Originally Posted by tah
Are you sure that it's true, does it work for any set S ? In fact if S could be partition into two sets of the same sum, then sum of S has to be even !! but take S = {1,2,3,4,5,6,7,8,9,10} and sum S is 55, so this S could not be partitioned in such a way ...
The question doesn't say it's a partition - merely that the subsets are distinct. I don't know that we can assume that this even means that they are disjoint, simply that they are not equal.
Having said that, I don't know how to tackle this question! But if I have any thoughts, I'll post them!
• February 20th 2009, 02:54 AM
tah
Quote:
Hello everyoneThe question doesn't say it's a partition - merely that the subsets are distinct. I don't know that we can assume that this even means that they are disjoint, simply that they are not equal.
Having said that, I don't know how to tackle this question! But if I have any thoughts, I'll post them!
Ahh right i see.
• February 20th 2009, 04:43 AM
Subsets
Hello sritter27
Quote:
Originally Posted by sritter27
Let S be a set of ten distinct positive integers, all less than 107. Prove that S has two distinct subsets that both have the same sum.
So I've been racking my mind over this and I cannot figure out how to write a proper proof for it. I was thinking the pigeon hole principle might help out somehow, but I'm not entirely sure how. I'd be rather grateful to anyone who can help point me in the right direction.
A set with 10 elements has $2^{10}$ = 1024 distinct subsets.
Maximum sum = 106 + 105 + ... + 97 = ...
Minimum sum = 1 + 2 + ... + 10 = ...
No of different sums = ...
Can you supply the rest?
PS. Sorry, that's not quite right. The minimum sum is zero - if the subset is the empty set.
• February 20th 2009, 09:22 AM
sritter27
Quote:
A set with 10 elements has $2^{10}$ = 1024 distinct subsets.
Maximum sum = 106 + 105 + ... + 97 = ...
Minimum sum = 1 + 2 + ... + 10 = ...
No of different sums = ...
Can you supply the rest?
PS. Sorry, that's not quite right. The minimum sum is zero - if the subset is the empty set.
Ah, I think it makes sense now.
So if there are 1024 possible subsets of S and the maximum sum of S is 1015 then there are fewer possible sums than possible subsets. So, by the pigeonhole principle there must be two subsets of S that have the same sum? If that is true then if two subsets have the same sum but are not distinct (non-disjoint), they can be made distinct by removing the common elements between them and thus they would still have the same sum.
Is this right?
• February 20th 2009, 10:15 AM
Sum of subsets
Hello sritter
Quote:
Originally Posted by sritter27
Ah, I think it makes sense now.
So if there are 1024 possible subsets of S and the maximum sum of S is 1015 then there are fewer possible sums than possible subsets. So, by the pigeonhole principle there must be two subsets of S that have the same sum? If that is true then if two subsets have the same sum but are not distinct (non-disjoint), they can be made distinct by removing the common elements between them and thus they would still have the same sum.
Is this right?
Yes, you can certainly make the subsets disjoint in this way without affecting the equality of their sums, although the question doesn't actually say 'disjoint', merely distinct (which usually, of course, means 'not equal').
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|
https://intl.siyavula.com/read/maths/grade-12/differential-calculus/06-differential-calculus-07
|
We think you are located in United States. Is this correct?
Applications of differential calculus
6.7 Applications of differential calculus (EMCHH)
Optimisation problems (EMCHJ)
We have seen that differential calculus can be used to determine the stationary points of functions, in order to sketch their graphs. Calculating stationary points also lends itself to the solving of problems that require some variable to be maximised or minimised. These are referred to as optimisation problems.
The fuel used by a car is defined by $$f\left(v\right)=\frac{3}{80}{v}^{2}-6v+245$$, where $$v$$ is the travelling speed in $$\text{km/h}$$.
What is the most economical speed of the car? In other words, determine the speed of the car which uses the least amount of fuel.
If we draw the graph of this function we find that the graph has a minimum. The speed at the minimum would then give the most economical speed.
We have seen that the coordinates of the turning point can be calculated by differentiating the function and finding the $$x$$-coordinate (speed in the case of the example) for which the derivative is $$\text{0}$$.
${f}'\left(v\right)=\frac{3}{40}v-6$
If we set $${f}'\left(v\right)=0$$ we can calculate the speed that corresponds to the turning point:
\begin{align*} {f}'\left(v\right) & = \frac{3}{40}v-6 \\ 0 & = \frac{3}{40}v-6 \\ v & = \frac{6\times 40}{3} \\ & = 80 \end{align*}
This means that the most economical speed is $$\text{80}\text{ km/h}$$.
Finding the optimum point:
Let $$f'(x) = 0$$ and solve for $$x$$ to find the optimum point.
To check whether the optimum point at $$x = a$$ is a local minimum or a local maximum, we find $$f''(x)$$:
• If $$f''(a) < 0$$, then the point is a local maximum.
• If $$f''(a) > 0$$, then the point is a local minimum.
Worked example 21: Optimisation problems
The sum of two positive numbers is $$\text{10}$$. One of the numbers is multiplied by the square of the other. If each number is greater than $$\text{0}$$, find the numbers that make this product a maximum.
Draw a graph to illustrate the answer.
Analyse the problem and formulate the equations that are required
Let the two numbers be $$a$$ and $$b$$ and the product be $$P$$.
\begin{align*} a+b &=10 \ldots \ldots (1) \\ P &= a \times b^{2} \ldots \ldots (2) \end{align*}
Make $$b$$ the subject of equation ($$\text{1}$$) and substitute into equation ($$\text{2}$$):
\begin{align*} P &= a\left(10-a\right)^{2} \\ &=a \left( 100 - 20a + a^{2} \right) \\ \therefore P(a) &= 100a - 20a^{2} + a^{3} \end{align*}
Differentiate with respect to $$a$$
${P}'\left(a\right)= 100 - 40a + 3a^{2}$
Determine the stationary points by letting $$P'(a) = 0$$
We find the value of $$a$$ which makes $$P$$ a maximum:
\begin{align*} {P}'\left(a\right) & = 3a^{2} -40a + 100 \\ 0 &= (3a - 10)(a - 10) \\ \therefore a = 10 & \text{ or } a = \frac{10}{3} \end{align*}
Substitute into the equation ($$\text{1}$$) to solve for $$b$$:
\begin{align*} \text{If } a = 10 : \enspace b & = 10 - 10 \\ & = 0 \enspace (\text{but } b > 0 ) \\ \therefore \text{no solution} \\ \\ \text{If } a = \frac{10}{3} : \enspace b & = 10 - \frac{10}{3} \\ & = \frac{20}{3} \end{align*}
Determine the second derivative $$P''(a)$$
We check that the point $$\left(\frac{10}{3};\frac{20}{3}\right)$$ is a local maximum by showing that $${P}''\left(\frac{10}{3}\right) < 0$$:
\begin{align*} {P}''\left(a\right) & = 6a -40 \\ \therefore {P}''\left(\frac{10}{3}\right) & = 6\left(\frac{10}{3}\right) -40 \\ & = 20 -40 \\ & = -20 \end{align*}
The product is maximised when the two numbers are $$\frac{10}{3}$$ and $$\frac{20}{3}$$.
Draw a graph
To draw a rough sketch of the graph we need to calculate where the graph intersects with the axes and the maximum and minimum function values of the turning points:
Intercepts:
\begin{align*} P(a) &= a^{3} -20a^{2} + 100a \\ &= a(a - 10)^{2} \\ & \\ \text{Let } P(a) = 0: \enspace & (0;0) \text{ and } (10;0) \end{align*}
Turning points:
\begin{align*} P'(a) & = 0 \\ \therefore a = \frac{10}{3} & \text{ or } a = 10 \end{align*}
Maximum and minimum function values:
\begin{align*} \text{Substitute } \left( \frac{10}{3}; \frac{20}{3} \right): \enspace P &= ab^{2} \\ &= \left( \frac{10}{3} \right) \left( \frac{20}{3} \right)^{2} \\ &= \frac{4000}{27} \\ & \approx 148 \qquad (\text{Maximum turning point})\\ & \\ \text{Substitute } (0;10): \enspace P &= ab^{2} \\ &= \left( 10 \right) \left( 0 \right)^{2} \\ &= 0 \qquad (\text{Minimum turning point}) \end{align*}
Note: the above diagram is not drawn to scale.
Worked example 22: Optimisation problems
Michael wants to start a vegetable garden, which he decides to fence off in the shape of a rectangle from the rest of the garden. Michael has only $$\text{160}\text{ m}$$ of fencing, so he decides to use a wall as one border of the vegetable garden. Calculate the width and length of the garden that corresponds to the largest possible area that Michael can fence off.
Examine the problem and formulate the equations that are required
The important pieces of information given are related to the area and modified perimeter of the garden. We know that the area of the garden is given by the formula:
$\text{Area }= w \times l$
The fencing is only required for $$\text{3}$$ sides and the three sides must add up to $$\text{160}\text{ m}$$.
$160 = w + l + l$
Rearrange the formula to make $$w$$ the subject of the formula:
$w=160 -2 l$
Substitute the expression for $$w$$ into the formula for the area of the garden. Notice that this formula now contains only one unknown variable.
\begin{align*} \text{Area } &= l(160 - 2l) \\ &= 160l - 2l^{2} \end{align*}
Differentiate with respect to $$l$$
We are interested in maximising the area of the garden, so we differentiate to get the following:
\begin{align*} \frac{dA}{dl} = A' &= 160 - 4l \end{align*}
Calculate the stationary point
To find the stationary point, we set $${A}'\left(l\right)=0$$ and solve for the value(s) of $$l$$ that maximises the area:
\begin{align*} {A}'\left(l\right) & = 160 - 4l \\ 0 &= 160 - 4l \\ 4l &= 160 \\ \therefore l &= 40 \end{align*}
Therefore, the length of the garden is $$\text{40}\text{ m}$$.
Substitute to solve for the width:
\begin{align*} w & = 160 -2l \\ & = 160 -2\left(40 \right) \\ & = 160 - 80 \\ & = 80 \end{align*}
Therefore, the width of the garden is $$\text{80}\text{ m}$$.
Determine the second derivative $${A}''\left(l\right)$$
We can check that this gives a maximum area by showing that $${A}''\left(l\right) < 0$$:
${A}''\left(l\right) = -4$
A width of $$\text{80}\text{ m}$$ and a length of $$\text{40}\text{ m}$$ will give the maximum area for the garden.
Important note:
The quantity that is to be minimised or maximised must be expressed in terms of only one variable. To find the optimised solution we need to determine the derivative and we only know how to differentiate with respect to one variable (more complex rules for differentiation are studied at university level).
Practise now to improve your marks
You can do it! Let us help you to study smarter to achieve your goals. Siyavula Practice guides you at your own pace when you do questions online.
Solving optimisation problems
Exercise 6.11
The sum of two positive numbers is $$\text{20}$$. One of the numbers is multiplied by the square of the other. Find the numbers that make this product a maximum.
Let the first number be $$x$$ and the second number be $$y$$ and let the product be $$P$$. We get the following two equations:
\begin{align*} x + y & = 20 \\ xy^{2} & = P \end{align*}
Rearranging the first equation and substituting into the second gives:
\begin{align*} P & = (20 - x)^{2}x \\ & = 400x - 40x^{2} + x^{3} \end{align*}
Differentiating and setting to $$\text{0}$$ gives:
\begin{align*} P' & = 400 - 80x + 3x^{2} \\ 0 & = 3x^{2} - 80x + 400 \\ & = (3x-20)(x-20) \end{align*}
Therefore, $$x=20$$ or $$x=\frac{20}{3}$$.
If $$x=20$$ then $$y=0$$ and the product is a minimum, not a maximum.
Therefore, $$x=\frac{20}{3}$$ and $$y=20-\frac{20}{3} = \frac{40}{3}$$.
Therefore the two numbers are $$\frac{20}{3}$$ and $$\frac{40}{3}$$ (approximating to the nearest integer gives $$\text{7}$$ and $$\text{13}$$).
A wooden block is made as shown in the diagram. The ends are right-angled triangles having sides $$3x$$, $$4x$$ and $$5x$$. The length of the block is $$y$$. The total surface area of the block is $$\text{3 600}\text{ cm^{2}}$$.
Show that $$y= \frac{\text{300} - x^{2}}{x}$$.
We start by finding the surface area of the prism:
\begin{align*} \text{Surface area} & = 2 \left(\frac{1}{2}b \times h\right) + 3xy + 4xy +5xy \\ \text{3 600} & = (3x \times 4x) + 12xy \\ & = 12x^{2} + 12 xy \end{align*}
Solving for $$y$$ gives:
\begin{align*} 12 xy & = \text{3 600} - 12x^{2} \\ y & = \frac{\text{3 600} - 12x^{2}}{12 x}\\ y& = \frac{\text{300} - x^{2}}{x} \end{align*}
Find the value of $$x$$ for which the block will have a maximum volume.
(Volume = area of base $$\times$$ height)
Start by finding an expression for volume in terms of $$x$$:
\begin{align*} V&=\text{ area of triangle } \times y \\ V & = 6x^{2} \times \frac{\text{300} - x^{2}}{x} \\ & = 6x ( \text{300} - x^{2})\\ & = \text{1 800}x - 6x^{3} \end{align*}
Now take the derivative and set it equal to $$\text{0}$$:
\begin{align*} V' & = \text{1 800} - 18x^{2} \\ 0 & = \text{1 800} - 18x^{2} \\ 18x^{2} & = \text{1 800} \\ x^{2} & = 100\\ x & = \pm 10 \end{align*}
Since the length can only be positive, $$x=10$$
$$\therefore x = \text{10}\text{ cm}$$
Determine the shortest vertical distance between the curves of $$f$$ and $$g$$ if it is given that: \begin{align*} f(x)&= -x^{2}+2x+3 \\ \text{and } g(x)&= \frac{8}{x}, \quad x > 0 \end{align*}
\begin{align*} \text{Let the distance } P(x) &= g(x) - f(x)\\ &=\frac{8}{x} - (-x^{2}+2x+3) \\ &=\frac{8}{x} +x^{2} - 2x - 3 \end{align*}
To minimise the distance between the curves, let $$P'(x) = 0:$$
\begin{align*} P'(x) &= - \frac{8}{x^2 } + 2x - 2 \qquad (x \ne 0) \\ 0 &= - \frac{8}{x^2 } + 2x - 2 \\ \therefore 0 &= - 8 + 2x^3 - 2x \\ 0 &= 2x^3 - 2x - 8 \\ 0 &= x^3 - x - 4 \\ 0 &= (x - 2)(x^2 + x + 2) \\ \therefore x =2 & \text{ or } x = \frac{-1 \pm \sqrt{(1)^2 - 4(1)(2)}}{2(1)} \\ & \quad = \text{ no real solutions } \\ \therefore x & =2 \end{align*}
Therefore, the shortest distance:
\begin{align*} P(2) &=\frac{8}{(2)} +(2)^{2} - 2(2) - 3 \\ &= 4 + 4 - 4 -3 \\ &= \text{1}\text{ unit} \end{align*}
The diagram shows the plan for a verandah which is to be built on the corner of a cottage. A railing $$ABCDE$$ is to be constructed around the four edges of the verandah.
If $$AB=DE=x$$ and $$BC=CD=y$$, and the length of the railing must be $$\text{30}\text{ m}$$, find the values of $$x$$ and $$y$$ for which the verandah will have a maximum area.
We need to determine an expression for the area in terms of only one variable.
The perimeter is:
\begin{align*} P & = 2x + 2y \\ 30 & = 2x + 2y \\ 15 & = x + y \\ y&=15-x \end{align*}
The area is:
\begin{align*} A & = y^{2} - (y-x)^{2} \\ & = y^{2} - (y^{2} - 2xy + x^{2}) \\ & = y^{2} - y^{2} + 2xy - x^{2} \\ & = 2xy - x^{2} \end{align*}
We use the expression for perimeter to eliminate the $$y$$ variable so that we have an expression for area in terms of $$x$$ only:
\begin{align*} A(x) & = 2x(15-x) - x^{2} \\ & = 30x - 2x^{2} - x^{2} \\ & = 30x - 3x^{2} \end{align*}
To find the maximum, we need to take the derivative and set it equal to $$\text{0}$$:
\begin{align*} A'(x) & = 30 - 6x \\ 0 & = 30 - 6x \\ 6x & = 30 \\ x & = 5 \end{align*}
Therefore, $$x=\text{5}\text{ m}$$ and substituting this value back into the formula for perimeter gives $$y=\text{10}\text{ m}$$.
A rectangular juice container, made from cardboard, has a square base and holds $$\text{750}\text{ cm}^{3}$$ of juice. The container has a specially designed top that folds to close the container. The cardboard needed to fold the top of the container is twice the cardboard needed for the base, which only needs a single layer of cardboard.
If the length of the sides of the base is $$x$$ cm, show that the total area of the cardboard needed for one container is given by: $A (\text{in square centimetres}) = \frac{\text{3 000}}{x} + 3x^{2}$
\begin{align*} V & = x^2h \\ 750 & = x^2h \\ \therefore h & = \frac{750}{x^2}\\ A & = \text{ area of sides } + \text{ area of base } + \text{ area of top } \\ &= 4xh + x^2 + 2x^2 \\ &= 4xh + 3x^2 \\ \text{Substitute } h &= \frac{750}{x^2}: \\ A &= 4x\left( \frac{750}{x^2} \right) + 3x^2 \\ &= \frac{3000}{x}+ 3x^2 \end{align*}
Determine the dimensions of the container so that the area of the cardboard used is minimised.
\begin{align*} A(x) &= \frac{3000}{x}+ 3x^2 \\ A'(x) &= - \frac{3000}{x^2}+ 6x \\ \therefore 0 &= - \frac{3000}{x^2}+ 6x \\ 6x &= \frac{3000}{x^2} \\ x^3 &= 500 \\ \therefore x &= \sqrt[3]{500} \\ &\approx \text{7,9}\text{ cm} \\ \therefore h & = \frac{750}{(\text{7,9})^2}\\ &\approx \text{12,0}\text{ cm} \end{align*}
Rates of change (EMCHK)
It is very useful to determine how fast (the rate at which) things are changing. Mathematically we can represent change in different ways. For example we can use algebraic formulae or graphs.
Graphs give a visual representation of the rate at which the function values change as the independent (input) variable changes. This rate of change is described by the gradient of the graph and can therefore be determined by calculating the derivative.
We have learnt how to determine the average gradient of a curve and how to determine the gradient of a curve at a given point. These concepts are also referred to as the average rate of change and the instantaneous rate of change.
$\text{Average rate of change } = \frac{f\left(x+h\right)-f\left(x\right)}{(x + h) - x}$ $\text{Instantaneous rate of change } = \lim_{h\to 0}\frac{f\left(x+h\right)-f\left(x\right)}{h}$
When we mention rate of change, the instantaneous rate of change (the derivative) is implied. When average rate of change is required, it will be specifically referred to as average rate of change.
Velocity is one of the most common forms of rate of change:
\begin{align*} \text{Average velocity } &= \text{Average rate of change } \\ & \\ \text{Instantaneous velocity } &= \text{Instantaneous rate of change } \\ &= \text{Derivative} \end{align*}
Velocity refers to the change in distance ($$s$$) for a corresponding change in time ($$t$$).
$v\left(t\right)=\frac{ds}{dt}={s}'\left(t\right)$
Acceleration is the change in velocity for a corresponding change in time. Therefore, acceleration is the derivative of velocity
$a\left(t\right)={v}'\left(t\right)$
This implies that acceleration is the second derivative of the distance.
$a\left(t\right)={s}''\left(t\right)$
Worked example 23: Rate of change
The height (in metres) of a golf ball $$t$$ seconds after it has been hit into the air, is given by $$H\left(t\right)=20t-5{t}^{2}$$. Determine the following:
1. The average vertical velocity of the ball during the first two seconds.
2. The vertical velocity of the ball after $$\text{1,5}$$ $$\text{s}$$.
3. The time at which the vertical velocity is zero.
4. The vertical velocity with which the ball hits the ground.
5. The acceleration of the ball.
Determine the average vertical velocity during the first two seconds
\begin{align*} {v}_{\text{ave}} & = \frac{H\left(2\right)-H\left(0\right)}{2-0} \\ & = \frac{\left[20\left(2\right)-5{\left(2\right)}^{2}\right]-\left[20\left(0\right)-5{\left(0\right)}^{2}\right]}{2} \\ & = \frac{40-20}{2} \\ & = \text{10}\text{ m.s$^{-1}$}\end{align*}
Calculate the instantaneous vertical velocity
\begin{align*} v\left(t\right) & = H'(t) \\ &= \frac{dH}{dt} \\ & = 20-10t \end{align*}
Velocity after $$\text{1,5}$$ $$\text{s}$$:
\begin{align*} v\left(\text{1,5}\right) & = 20-10\left(\text{1,5}\right) \\ & = \text{5}\text{ m.s$^{-1}$} \end{align*}
Determine the time at which the vertical velocity is zero
\begin{align*} v\left(t\right) & = 0 \\ 20-10t & = 0 \\ 10t & = 20 \\ t & = 2 \end{align*}
Therefore, the velocity is zero after $$\text{2}\text{ s}$$
Find the vertical velocity with which the ball hits the ground
The ball hits the ground when $$H\left(t\right)=0$$
\begin{align*} 20t-5{t}^{2} & = 0 \\ 5t\left(4-t\right) & = 0 \\ t=0& \text{ or } t=4 \end{align*}
The ball hits the ground after $$\text{4}$$ $$\text{s}$$. The velocity after $$\text{4}$$ $$\text{s}$$ will be:
\begin{align*} v\left(4\right) & = {H}'\left(4\right) \\ & = 20-10\left(4\right) \\ & = -\text{20}\text{ m.s$^{-1}$} \end{align*}
The ball hits the ground at a speed of $$\text{20}\text{ m.s^{-1}}$$. Notice that the sign of the velocity is negative which means that the ball is moving downward (a positive velocity is used for upwards motion).
Acceleration
\begin{align*} a=v'(t)&=H''(t) \\ &=-10 \end{align*}\begin{align*} \therefore a & = -\text{10}\text{ m.s$^{-2}$} \end{align*}
Just because gravity is constant does not mean we should necessarily think of acceleration as a constant. We should still consider it a function.
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Rates of change
Exercise 6.12
A pump is connected to a water reservoir. The volume of the water is controlled by the pump and is given by the formula: \begin{align*} V(d)&=64+44d-3d^{2} \\ \text{where } V&= \text{ volume in kilolitres}\\ d&= \text{ days} \end{align*}
Determine the rate of change of the volume of the reservoir with respect to time after $$\text{8}$$ days.
\begin{align*} \text{Rate of change }&= V'(d) \\ V'(d)&= 44 -6d \\ \text{After 8 days, rate of change will be:}\\ V'(8)&=44-6(8)\\ &= -\text{4}\text{ kℓ per day} \end{align*}
Is the volume of the water increasing or decreasing at the end of $$\text{8}$$ days. Explain your answer.
The rate of change is negative, so the function is decreasing.
After how many days will the reservoir be empty?
\begin{align*} \text{Reservoir empty: } V(d)&=0 \\ \therefore 64 + 44d -3d^{2}&=0 \\ (16-d)(4+3d)&=0\\ \therefore d = 16 \text{ or } & d = -\frac{4}{3} \\ \therefore \text{ It will be empty after } \text{16}\text{ days} \end{align*}
When will the amount of water be at a maximum?
Maximum at turning point.
\begin{align*} \text{Turning point where } V'(d)&= 0 \\ \therefore 44 - 6d&=0\\ d &=\frac{44}{6} \\ &= 7\frac{1}{3} \text{ days} \end{align*}
Calculate the maximum volume.
Maximum at turning point.
\begin{align*} \text{Maximum volume } &= V\left(\frac{22}{3}\right) \\ V\left(\frac{22}{3}\right) &= 64 + 44\left(\frac{22}{3}\right) - 3\left(\frac{22}{3}\right)^{2} \\ &= \text{225,3}\text{ kℓ} \end{align*}
Draw a graph of $$V(d)$$.
A soccer ball is kicked vertically into the air and its motion is represented by the equation: \begin{align*} D(t)&=1 + 18t -3t^{2} \\ \text{where } D &= \text{distance above the ground (in metres)} \\ t&= \text{ time elapsed (in seconds)} \end{align*}
Determine the initial height of the ball at the moment it is being kicked.
\begin{align*} D(t)&=1 + 18t - 3t^{2} \\ D(0)&=1 + 18(0) - 3(0)^{2} \\ &= 1 \text{ metre} \end{align*}
Find the initial velocity of the ball.
\begin{align*} \text{Velocity } = D'(t) &= 18 - 6t \\ \text{Initial velocity } &= D'(0) \\ D'(0) =18 - 6(0) &=\text{18}\text{ m.s$^{-1}$} \end{align*}
Determine the velocity of the ball after $$\text{1,5}$$ $$\text{s}$$.
\begin{align*} \text{Velocity after } \text{1,5}\text{ s}&=D'(\text{1,5}) \\ D'(\text{1,5})&=18-6(\text{1,5})^{2} \\ &=18-9 \\ &=\text{9}\text{ m.s$^{-1}$} \end{align*}
Calculate the maximum height of the ball.
Maximum height is at the turning point.
\begin{align*} \text{Turning point: } D'(t)&=0 \\ \therefore 18 - 6t&=0\\ 6t&=18 \\ t&=\text{3}\text{ s} \\ \text{Maximum height }&=D(3) \\ &=1+(18)(3)-(3)(3)^{2} \\ &=\text{28}\text{ metres} \end{align*}
Determine the acceleration of the ball after $$\text{1}$$ second and explain the meaning of the answer.
\begin{align*} \text{Acceleration }&= D''(t) \\ D''(t)&= -\text{6}\text{ m.s$^{-2}$} \end{align*}
Interpretation: the velocity is decreasing by $$\text{6}$$ metres per second per second.
Calculate the average velocity of the ball during the third second.
Average velocity during third second:
\begin{align*} &= \frac{D(3)-D(2)}{3-2} \\ &= \frac{1+18(3)-3(3)^{2}-\left[1+18(2)-3(2)^{2}\right]}{1} \\ &= \text{3}\text{ m.s$^{-1}$} \end{align*}
Determine the velocity of the ball after $$\text{3}$$ seconds and interpret the answer.
\begin{align*} \text{Instantaneous velocity}&= D'(3) \\ &= 18-6(3) \\ &= \text{0}\text{ m.s$^{-1}$} \end{align*}
Interpretation: this is the stationary point, where the derivative is zero. The ball has stopped going up and is about to begin its descent.
How long will it take for the ball to hit the ground?
\begin{align*} \text{Hits ground: } D(t)&=0 \\ -3t^{2}+18t+1&=0\\ t&=\frac{-18 \pm\sqrt{(18^{2}-4(1)(-3)}}{2(-3)} \\ t&=\frac{-18\pm\sqrt{336}}{-6} \\ \therefore t&=-\text{0,05} \text{ or } t=\text{6,05} \end{align*}
The ball hits the ground at $$\text{6,05}$$ $$\text{s}$$ (time cannot be negative).
Determine the velocity of the ball when it hits the ground.
\begin{align*} \text{Velocity after } \text{6,05}\text{ s}&= D'(\text{6,05}) \\ D'(\text{6,05})=18-5(\text{6,05})&= -\text{18,3}\text{ m.s$^{-1}$} \end{align*}
If the displacement $$s$$ (in metres) of a particle at time $$t$$ (in seconds) is governed by the equation $$s=\frac{1}{2}{t}^{3}-2t$$, find its acceleration after $$\text{2}$$ seconds.
We know that velocity is the rate of change of displacement. This means that $$\frac{dS}{dt} = v$$: \begin{align*} s &=\frac{1}{2}t^{3} - 2t \\ v &=\frac{3}{2}t^{2} - 2 \end{align*}
We also know that acceleration is the rate of change of velocity. This means that $$\frac{dv}{dt} = a$$: \begin{align*} v &=\frac{3}{2}t^{2} - 2 \\ a &= 3t \end{align*}
Substituting $$t=2$$ gives $$a=\text{6}\text{ m.s^{-2}}$$.
During an experiment the temperature $$T$$ (in degrees Celsius) varies with time $$t$$ (in hours) according to the formula: $$T\left(t\right)=30+4t-\frac{1}{2}{t}^{2}, \enspace t \in \left[1;10\right]$$.
Determine an expression for the rate of change of temperature with time.
We find the rate of change of temperature with time by differentiating: \begin{align*} T(t) &=30+4t-\frac{1}{2}t^{2} \\ T'(t) &= 4 - t \end{align*}
During which time interval was the temperature dropping?
We set the derivative equal to $$\text{0}$$: \begin{align*} 0 &= 4 - t \\ t &= 4 \end{align*} We look at the coefficient of the $$t^{2}$$ term to decide whether this is a minimum or maximum point. The coefficient is negative and therefore the function must have a maximum value. The interval in which the temperature is increasing is $$[1;4)$$. The interval in which the temperature is dropping is $$(4;10]$$. We can check this by drawing the graph or by substituting in the values for $$t$$ into the original equation.
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https://www.itdroplets.com/tag/2012/
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# Content Location shows the package as distributed but it’s not
I had this issues for a while and I ended up creating a ticket with Microsoft as I couldn’t get any answer to my issue. I’ve also posted this on technet, but nobody dared to answer 🙂
The reason why I wanted to open a ticket with Microsoft is that I have had a few issues since the migration to 2012 R2 and to be honest this kind of error it’s ok once, but what if it happens again? I could have just removed the package and started from scratch, that would have fixed it but this time I’ve been stubborn and I’ve learnt something new. Also, the package was 4GB, multiply that for all the Distribution Points. I don’t like to waste time if I don’t have to.
Here’s the post: SCCM Console is lying to me! Content shows as distributed but it isn’t.
### The issue
In my case, this happened with one of the Microsoft Office Deployment Packages I created.
When I clicked on the Deployment Package, the Status at the bottom of the console would tell me that the content was distributed (correctly) to 6 Distribution Points but when I actually went in the Deployment Package’s properties I could see like 10 Distribution Points in there. So basically Content Location shows the package as distributed but it’s not.
If I tried to Remove/Validate/Redistribute the content, nothing would happen. I couldn’t even treat this as a new distribution as the phantom Distribution Points would not appear as it happens when the content is already distributed.
I was able to distribute this content to other DPs. Updating the content did not help either.
I’ve also tried to either distribute (Start-CMContentDistribution) and remove (Remove-CMContentDistribution) the package from these DPs via PowerShell but also here no luck. When I tried to distribute it, it told me that the package was already distributed, when I removed it, nothing happened as when I did it through the console.
I then checked one of the Distribution Points through Content Library Explorer and I could see that the content was grayed out and the package ID had a * right after the ID. Also here I could not validate nor re-distribute the content.
### The cause
No idea! Microsoft went through the logs and found nothing. The engineer told me that he’s never seen such an issue before.
### The solution
Well, as there was no root cause, the only solution that Microsoft suggested was to manually delete the entries of these Distribution Points, associated to the Package ID, from the SQL server. (more…)
# Task sequence has failed with the error code 0x800700A1
I see lots of administrators struggling with this error especially when they replace an HDD on a machine and then try to re-image it. Task sequence has failed with the error code 0x800700A1 is an error that also come up when you’re imagining a brand new Virtual Machine.
What does the error mean? 0x800700A1 means BAD_PATHNAME. The reason why you get this error, most of the times, is due the fact that the task sequence isn’t able to find the path because the drive is RAW.
In order to fix this you will have to initialize and format that Hard Drive. If you are in the SCCM’s WinPE environment, simply press F8 to get to the command prompt and type the following:
(more…)
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https://math.stackexchange.com/questions/3462958/moore-penrose-pseudoinverse-of-a-matrix-product
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# Moore-Penrose Pseudoinverse of a matrix product
$$X_{n \times p}$$ is a real, thin ($$n>p$$) rectangular matrix of rank $$p$$, so $$X^T X$$ is full rank. The Moore-Penrose pseudoinverse of $$X$$ is given by $$X^+=(X^TX)^{-1}X^T$$.
Let's now define $$W=XA$$
($$X$$ is linearly transformed by $$A_{p \times k}$$ to produce a $$W_{n \times k}$$). $$W$$ is of rank $$k$$ (so $$W^TW$$ is full rank).
I need to compute the Moore-Penrose Pseudoinverse of $$W$$ for many different $$A$$ matrices efficiently. Is there an identity or a decomposition that allows expressing $$W^+$$ as some function of $$X^+$$ or $$(X^TX)^{-1}$$?
due to distributive order reversal rule for transposing multiple and associativity of multiplication , $$W^+=(A^T (X^TX) A)^{-1} A^T X^T$$ not too much opportunity for pre-calculation it seems
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http://unix.stackexchange.com/questions/16804/ext4-overrides-my-commit-100-mount-option-with-commit-0?answertab=votes
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# ext4 overrides my commit=100 mount option with commit=0
Here is the relevant line from my /etc/fstab file:
UUID=f51aa298-9ce4-4a19-a323-10df333f34f5 / ext4 data=writeback,noatime,barrier=0,errors=remount-ro,commit=100,nobh,nouser_xattr 0 1
Here is what happens when I type the command "mount":
/dev/sda1 on / type ext4 (rw,noatime,data=writeback,barrier=0,errors=remount-ro,commit=100,nobh,nouser_xattr,commit=0)
Why does it specify "commit=0" at the end? Does it mean that my commit=100 option is not used?
I am using Ubuntu 10.10, 32-bit with the latest updates.
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What does grep ' / ' /proc/mounts show? The information in /proc/mounts comes directly from the kernel, whereas mount uses information in /etc/mtab, which might not be up-to-date for /. – Gilles Jul 16 '11 at 19:36
/dev/disk/by-uuid/f51aa298-9ce4-4a19-a323-10df333f34f5 / ext4 rw,noatime,errors=remount-ro,barrier=0,nobh,data=writeback 0 0 – Alex Jul 16 '11 at 19:38
@Gilles - Why would /etc/mtab become out of date? Curious. – boehj Jul 16 '11 at 23:05
@boehj /etc/mtab is updated by mount, if it can. / is normally mounted read-only by the kernel or the initrd/initramfs, the remounted read-write as part of the boot process. I'm not sure if the final mount options (from /etc/fstab) are always recorded correctly. – Gilles Jul 16 '11 at 23:11
@Gilles - Interesting. – boehj Jul 17 '11 at 0:49
Got it. It seems the problem was with the /usr/lib/pm-utils/power.d/journal-commit file. I edited the above file as root and changed the line
JOURNAL_COMMIT_TIME_AC=${JOURNAL_COMMIT_TIME_AC:-0} to be JOURNAL_COMMIT_TIME_AC=${JOURNAL_COMMIT_TIME_AC:-100}
And that's all!
P.S - I have no idea why the script ignores conflicting mount options. I believe it should check for user-specified options and not override them.
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That's not a good solution. Next time you update your pm-utils (or whatever owns that file, I'm not an Ubuntu guy) your script may be hosed. The \${JOURNAL_COMMIT_TIME_AC:-100} is a bash thing that says if JOURNAL_COMMIT_TIME_AC is NOT defined, set it to 100. So you need to set that value somewhere that the script reads it. In RedHat systems, it would be somewhere in /etc/sysconfig/ - you need to trace the script and see where it would have read it from. – Aaron D. Marasco Jul 23 '11 at 13:21
Oh, and as for ignoring the /etc/fstab entry, that would be a bug report against the software. Unless there is a distro-specific setup program you were supposed to use that would have set it properly there and recorded it somewhere for the startup script to find. – Aaron D. Marasco Jul 23 '11 at 13:25
@Aaron, you are right of course. This is not a solution but a work-around. – Alex Jul 24 '11 at 19:01
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https://manual.q-chem.com/latest/Ch12.S18.SS2.html
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# 12.18.2 Job Control
(February 4, 2022)
In addition to the normal TDDFT job controls variables described in Section 7.3.3, there are several others to request TDDFT(MI). Note that only single-point energies (not gradients) are available for this method.
TDDFT_MI
TDDFT_MI
Perform an TDDFT(MI) calculation
TYPE:
LOGICAL
DEFAULT:
FALSE
OPTIONS:
FALSE Do not perform an TDDFT(MI) calculation TRUE Perform an TDDFT(MI) calculation
RECOMMENDATION:
False
MI_ACTIVE_FRAGMENT
MI_ACTIVE_FRAGMENT
Sets the active fragment
TYPE:
INTEGER
DEFAULT:
NO DEFAULT
OPTIONS:
$n$ Specify the fragment on which the TDDFT calculation is to be performed, for LEA-TDDFT(MI).
RECOMMENDATION:
None
MI_LEA
MI_LEA
Controls the LEA-TDDFT(MI) methods
TYPE:
INTEGER
DEFAULT:
NO DEFAULT
OPTIONS:
0 The LEA0 method 1 The LEA-Q method 2 The LEAc method
RECOMMENDATION:
1
|
{"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 8, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.2076028734445572, "perplexity": 23212.073493217606}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-21/segments/1652662539131.21/warc/CC-MAIN-20220521143241-20220521173241-00790.warc.gz"}
|
https://www.nag.com/numeric/py/nagdoc_latest/naginterfaces.library.ieee.create_infinity.html
|
# naginterfaces.library.ieee.create_infinity¶
naginterfaces.library.ieee.create_infinity(isign)[source]
create_infinity creates a signed infinite value.
For full information please refer to the NAG Library document for x07ba
https://www.nag.com/numeric/nl/nagdoc_27.1/flhtml/x07/x07baf.html
Parameters
isignint
Determines the sign of the infinity to be created.
If is greater than or equal to , a positive infinity is returned, otherwise a negative infinity is returned.
Returns
xfloat
The required infinite value.
Notes
create_infinity sets to be positive or negative infinity.
References
IEEE, 2008, Standard for Floating-Point Arithmetic (IEEE Standard 754-2008), IEEE, New York.
|
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|
https://link.springer.com/article/10.1007%2FJHEP06%282012%29098
|
# Constrained supersymmetry after two years of LHC data: a global view with Fittino
## Abstract
We perform global fits to the parameters of the Constrained Minimal Super-symmetric Standard Model (CMSSM) and to a variant with non-universal Higgs masses (NUHM1). In addition to constraints from low-energy precision observables and the cosmological dark matter density, we take into account the LHC exclusions from searches in jets plus missing transverse energy signatures with about 5 fb−1 of integrated luminosity. We also include the most recent upper bound on the branching ratio B s → μμ from LHCb. Furthermore, constraints from and implications for direct and indirect dark matter searches are discussed. The best fit of the CMSSM prefers a light Higgs boson just above the experimentally excluded mass. We find that the description of the low-energy observables, (g − 2) μ in particular, and the non-observation of SUSY at the LHC become more and more incompatible within the CMSSM. A potential SM-like Higgs boson with mass around 126 GeV can barely be accommodated. Values for $$\mathcal{B}\left( {{B_{\text{s}}} \to \mu \mu } \right)$$ just around the Standard Model prediction are naturally expected in the best fit region. The most-preferred region is not yet affected by limits on direct WIMP searches, but the next generation of experiments will probe this region. Finally, we discuss implications from fine-tuning for the best fit regions.
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## Author information
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Correspondence to Philip Bechtle.
ArXiv ePrint: 1204.4199
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Bechtle, P., Bringmann, T., Desch, K. et al. Constrained supersymmetry after two years of LHC data: a global view with Fittino. J. High Energ. Phys. 2012, 98 (2012). https://doi.org/10.1007/JHEP06(2012)098
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https://www.physicsforums.com/threads/crystal-lattice-and-unit-cell.110932/
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# Homework Help: Crystal lattice and unit cell
1. Feb 16, 2006
### asdf1
what's the difference between those two?
2. Feb 16, 2006
### assyrian_77
A lattice is a (idealized) structure of crystals where each lattice point represent an identical group of atoms. A group is sometimes called a basis. One can form basis vectors with which all lattice point positions can be expressed. The unit cell (I guess you mean the primitive cell) is the volume defined by the set of basis vectors. This is the smallest volume; there are no cells with smaller volumes.
Hopefully this was of help. If not, don't hesitate to ask.
3. Feb 16, 2006
### Gokul43201
Staff Emeritus
What does your textbook or class notes say ?
4. Feb 17, 2006
### asdf1
my textbook says:
unit cell: crystal structure that's the smallest group of atoms possessing
the symmetry of the crystal
lattice: orderly array of points in space
so does that mean that the unit cell is part of the lattice?
5. Feb 17, 2006
### Gokul43201
Staff Emeritus
Yes, it is the smallest "representative" part.
6. Feb 17, 2006
### asdf1
ok, thanks!!!
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http://mathhelpforum.com/trigonometry/128324-worked-solution-provided-but-why-z-360-deg-rejected.html
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# Math Help - Worked solution provided, but why is z = 360 deg rejected?
1. ## Worked solution provided, but why is z = 360 deg rejected?
Can any kind soul help me in the below?
Find z between 0 and 360 degrees which satisfy the equation.
1. sec^2 z = 4 sec z - 3
sec^2 z = 4 sec z - 3
sec^2 z - 4 sec z + 3 = 0
(sec z - 3)( sec z - 1) = 0
sec z = 3 or sec z = 1
cos z = 1/3 or cos z = 1
z = 70.5 deg, z = 0, 360 deg(rejected)
cos is positive => so in 1st or 4th quadrant
z = 70.5, 360-70.5
= 70.5, 289.5
My question: why is z = 360 deg rejected?
why is z = 0 deg not rejected?
2. Originally Posted by ppppp77
My question: why is z = 360 deg rejected?
why is z = 0 deg not rejected?
It is not clear why in this case, was your domain $[0,360)$ or $[0,360]$ ?
3. Originally Posted by ppppp77
Can any kind soul help me in the below?
Find z between 0 and 360 degrees which satisfy the equation.
1. sec^2 z = 4 sec z - 3
sec^2 z = 4 sec z - 3
sec^2 z - 4 sec z + 3 = 0
(sec z - 3)( sec z - 1) = 0
sec z = 3 or sec z = 1
cos z = 1/3 or cos z = 1
z = 70.5 deg, z = 0, 360 deg(rejected)
cos is positive => so in 1st or 4th quadrant
z = 70.5, 360-70.5
= 70.5, 289.5
My question: why is z = 360 deg rejected?
why is z = 0 deg not rejected?
oh my, pickslides, you are really awesome!!
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http://worldwidescience.org/topicpages/v/vegetation+types+ecological.html
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Sample records for vegetation types ecological
1. [Ecological stoichiometric characteristics in leaf and litter under different vegetation types of Zhifanggou watershed on the Loess Plateau, China].
Science.gov (United States)
Li, Xin; Zeng, Ouan-chao; An, Shao-Shan; Dong, Yang-Hong; Li, Ya-Yun
2015-03-01
The purpose was to characterize the effects of vegetation types on plant leaf and litter carbon (C), nitrogen (N), phosphorus (P), potassium (K) and C: N: P: K ecological stoichiometric characteristics in seven dominant plant species, including Robinia pseudoacacia, Syringa, Sophora viciifolia, Hippophae rhamnoides, Rosa xanthina, Artemisia sacrorum, Artemisia giraldii, of Zhifanggou Watershed on the Loess Plateau, China. This paper indicated the differences between the contents of C, N, P and K and the characteristics of ecological stoichiometric in the different vegetation types, including forest type, shrub type and grass type. Concentrations of C, N, P and K were measured, and C: N: P: K was estimated for different vegetation types. There were no significant differences in leaf C, N and P concentrations among the three vegetation types. But significant differences in leaf K concentration existed, and the K concentration in leaf was the highest in grass type, and the lowest in shrub type. The contents of C, N, P and K in leaf were much higher than those in litter, especially in shrub and grass types. The resorption efficiencies of C, N, P and K were different, and their ranges varied 6.16%-22.84%, 24.38%-65.18%, 22.38%-77.16% and 60.99%- 89.35%, respectively. Grass type had the highest C, P and K resorption efficiencies, and the lowest N resorption efficiency. Values of the N: P ratio in leaf varied in the range of 12.14-19.17, and varied in the range of 12.84-30.67 in litter. Values of the N: P ratio in leaf were the highest in shrub type (19. 17), and the lowest in grass (12. 14), indicating that the growth of shrub plants was limited by P, while the growth of grass plants was limited by N. The K concentration in leaf was significantly negatively correlated with values of the N: P ratio in leaf, and the K concentration in litter was significantly negatively correlated with values of the C: P ratio in leaf. Findings in this study highlighted the characteristics of accumulation and and return of leaf and litters nutrients during the different vegetation succession on the Loess Plateau. PMID:25929080
2. Description of vegetation types
US Fish and Wildlife Service, Department of the Interior — This document describes the types of woody vegetation that are found in Iowa. This document provides descriptions of five vegetation types found in Iowa oak...
3. Between Design and Ecology. Innovative herbaceous vegetation
DEFF Research Database (Denmark)
BjØrn, Mona Chor
2015-01-01
Urban green space offers more than recreation - it is a resource and a habitat for flora and wildlife. Since 2000 numerous articles have documented an increased public awareness of urban nature and biodiversity. As a result there has been increased interest in new vegetation types in urban and suburban environments. Colourful species-rich forb vegetation may be one possible way to link recreational values, aesthetical preferences and herbaceous vegetation with habitat requirements for diverse flora and fauna in urban and suburban environments. The overall aim of this thesis is to improve our current understanding, both theoretical and practical, of the design and dynamical changes in low resource requiring, colourful forb vegetation. Through literature and an experimental field study, this thesis contributes to new perspectives on the possibilities for and limitations of creating and managing such vegetation, based on concepts and theories in plant community ecology. If these communities are based on localforbs there is a continuum in anthropogenic intervention from designed and intensively maintained to semi-natural herbaceous vegetation. Results from a large field experiment show that, after three years, bare soil re-vegetates to become grass-dominated herbaceous vegetation with plant density and standing biomass similar to that of experimental species-rich forb vegetation. Standing biomass can be used as a measure to predict community development after disturbance. For a given biomass production, however, species-richness may be low or high. Some perennial forb species show good persistence in the face of competition from grasses and other weeds, while other species disappear quickly. Unexpected longevity of some monocarpic and polycarpic species may explain forb survivorship and a negative response to mowing during the summer. Predicting the growth of herbaceous plant communities is challenging. Our results show that, when grown at the same density, the biomass production of forbs is highly variable andspecies specific. Plants are dynamic organisms, which respond physically to changes in the environment. There is a need to investigate the use of strategic interventions to secure persistence and regeneration of species-rich colourful forb vegetation. Disturbance is important to facilitate recruitment from seed as well as vegetative spread. Without some disturbance, forb vegetation will become colonised by grasses and eventually woody species. This thesis adds useful basic knowledge in plant community ecology and species-specific growth, which are relevant to research and planning in landscape architecture and ecology.
4. Next generation dynamic global vegetation models: learning from community ecology
Science.gov (United States)
Scheiter, Simon; Higgins, Steven; Langan, Liam
2013-04-01
Dynamic global vegetation models are a powerful tool to project the past, current and future distribution of vegetation and associated water and carbon fluxes. However, most models are limited by how they define vegetation and by their simplistic representation of competition. We discuss how concepts from community assembly theory and coexistence theory can help to improve vegetation models. We further present a new trait- and individual-based dynamic vegetation model (the aDGVM2) that allows each individual plant to adopt a unique combination of trait values. These traits define how each individual plant grows and competes with other plants under given environmental conditions. The performance of individual plants in turn drives the assembly of a plant community. A genetic optimisation algorithm is used to simulate the inheritance of traits and different levels of reproductive isolation between individuals. Together these model properties allow the assembly of plant communities that are well adapted to a site's biotic and abiotic conditions. Simulated communities can be classified into different plant functional types or biome types by using trait data bases. We illustrate that the aDGVM2 can simulate (1) how environmental conditions and changes in these conditions influence the trait spectra of assembled plant communities, (2) that fire selects for traits that enhance fire protection and reduces trait diversity, and (3) the emergence of communities dominated by life history strategies that are suggestive of colonisation-competition trade-offs. The aDGVM2 deals with functional diversity and competition fundamentally differently from current dynamic vegetation models. We argue that this approach will yield novel insights as to how vegetation may respond to climate change and we believe that it could foster fruitful collaborations between research communities that focus on plant functional traits, plant competition, plant physiology, systems ecology and earth system science.
5. LANDSCAPE ECOLOGICAL METHOD TO STUDY AGRICULTURAL VEGETATION: SOME EXAMPLES FROM THE PO VALLEY
Directory of Open Access Journals (Sweden)
E. GIGLIO
2006-01-01
Full Text Available Vegetation is the most important landscape component, as regards to its ability to catch solar energy and to transform it, but also to shape the landscape, to structure the space, to create the fit environment for different animal species, to contribute to the maintenance of a correct metastability level for the landscape, etc. It is a biological system which acts under the constraints of the principles of the System Theory and owns the same properties of any other living system: so, it is a complex adaptive, hierarchical, dynamic, dissipative, self-organizing, self-transcendent, autocatalytic, self-maintaining system and follows the non-equilibrium thermodynamic. Its ecological state can be investigated through the comparison between “gathered data” (pathology and “normal data” (physiology for analogous types of vegetation. The Biological Integrated School of Landscape Ecology provides an integrated methodology to define ecological threshold limits of the different Agricultural Landscape types and applies to agricultural vegetation the specific part of the new methodology already tested to studying forests (the Landscape Biological Survey of Vegetation. Ecological quality, better and worst parameters, biological territorial capacity of vegetated corridors, agricultural field, poplar groves, orchards and woody remnant patches are investigated. Some examples from diverse agricultural landscapes of the Po Valley will be discussed. KEY WORDS: agricultural landscape, vegetation, landscape ecology, landscape health, Biological Integrated Landscape Ecology, Landscape Biological Survey of vegetation.
6. The vegetation of Yucca Mountain: Description and ecology
International Nuclear Information System (INIS)
Vegetation at Yucca Mountain, Nevada, was monitored over a six-year period, from 1989 through 1994. Yucca Mountain is located at the northern limit of the Mojave Desert and is the only location being studied as a potential repository for high-level nuclear waste. Site characterization consists of a series of multidisciplinary, scientific investigations designed to provide detailed information necessary to assess the suitability of the Yucca Mountain Site as a repository. This vegetation description establishes a baseline for determining the ecological impact of site characterization activities; it porvides input for site characterization research and modeling; and it clarifies vegetation community dynamics and relationships to the physical environment. A companion study will describe the impact of site characterization of vegetation. Cover, density, production, and species composition of vascular plants were monitored at 48 Ecological Study Plots (ESPs) stratified in four vegetation associations. Precipitation, soil moisture, and maximum and minimum temperatures also were measured at each study plot
7. The vegetation of Yucca Mountain: Description and ecology
Energy Technology Data Exchange (ETDEWEB)
NONE
1996-03-29
Vegetation at Yucca Mountain, Nevada, was monitored over a six-year period, from 1989 through 1994. Yucca Mountain is located at the northern limit of the Mojave Desert and is the only location being studied as a potential repository for high-level nuclear waste. Site characterization consists of a series of multidisciplinary, scientific investigations designed to provide detailed information necessary to assess the suitability of the Yucca Mountain Site as a repository. This vegetation description establishes a baseline for determining the ecological impact of site characterization activities; it porvides input for site characterization research and modeling; and it clarifies vegetation community dynamics and relationships to the physical environment. A companion study will describe the impact of site characterization of vegetation. Cover, density, production, and species composition of vascular plants were monitored at 48 Ecological Study Plots (ESPs) stratified in four vegetation associations. Precipitation, soil moisture, and maximum and minimum temperatures also were measured at each study plot.
8. Ecological problems and nitrogen balance in vegetable crops growing
Directory of Open Access Journals (Sweden)
Tsetska Simeonova
2015-01-01
Full Text Available The purpose of this study is to focus on the nitrogen balance and losses in agricultural system. The influence of precipitation, irrigation and fertilizer application on some soil parameters, N-uptake by plant production and N-output by lysimetric water are evaluated in this paper.The study is carried out on Fluvisol, near Plovdiv in Southern Bulgaria under the conditions of field experiments with different vegetable crops (eggplant, green beans and carrots over the period 2009-2011. The experimental design includes 3 treatments with nitrogen application –N0, N80 and N160 on the background of P80K80 kg.ha-1. The field plots are equipped with modification of Ebermayer type of lysimeters, which collect water from 100 cm depth of soil profile.According the received data it was observed that compensation between the amounts of N input and output was achieved in two variants (N80, N160 for all crops growing. Reducing the nitrogen input to the amount applied by precipitation and irrigation waters is the most ecological-friendly technological decision and very important factor for environment protection.
9. Alternative Ecology of Human Pathogenic Bacteria in Fruits and Vegetables
Directory of Open Access Journals (Sweden)
A. Nithya
2014-01-01
Full Text Available Outbreaks of illness due to human enteric pathogenic bacteria via fresh vegetables warrant intensive research on changing strategies of these bacteria in alterning their hosts for survival. The systemic infection of human pathogenic bacteria in plants and the plant growth stage at which they establish endophytic relationship is poorly understood. The issue is magnified in countries like India where the dietary habits are changing and consumption of fresh fruits and vegetables as salad has become a part in the everyday menu of most people. Most of the human pathogenic enteric bacteria are generally characterized by broad host ranges and these pathogens seem to exploit almost any change in human ecology that provides new opportunities for transmission. Because plants are not traditionally considered as hosts for human enteric pathogens, recent produce-associated outbreaks highlight important deficiencies in our understanding of the ecology of enteric pathogens outside of their human and animal hosts. This review focuses on understanding the human enteric pathogens that have developed abilities to colonize internal tissues of vegetables and fruits popularly consumed as salads, how and when do they enter plants and where do they localize in plant tissues. In addition, we have also highlighted the attempts made in detection and control of these bacteria in plant hosts. This understanding will help develop strategies towards vegetable food safety in a joint effort by agriculturalists, environmentalists, food processing agencies, whole salers and retailers, which will ultimately benefit every consumer.
10. New vegetation type map of India prepared using satellite remote sensing: Comparison with global vegetation maps and utilities
Science.gov (United States)
Roy, P. S.; Behera, M. D.; Murthy, M. S. R.; Roy, Arijit; Singh, Sarnam; Kushwaha, S. P. S.; Jha, C. S.; Sudhakar, S.; Joshi, P. K.; Reddy, Ch. Sudhakar; Gupta, Stutee; Pujar, Girish; Dutt, C. B. S.; Srivastava, V. K.; Porwal, M. C.; Tripathi, Poonam; Singh, J. S.; Chitale, Vishwas; Skidmore, A. K.; Rajshekhar, G.; Kushwaha, Deepak; Karnatak, Harish; Saran, Sameer; Giriraj, A.; Padalia, Hitendra; Kale, Manish; Nandy, Subrato; Jeganathan, C.; Singh, C. P.; Biradar, C. M.; Pattanaik, Chiranjibi; Singh, D. K.; Devagiri, G. M.; Talukdar, Gautam; Panigrahy, Rabindra K.; Singh, Harnam; Sharma, J. R.; Haridasan, K.; Trivedi, Shivam; Singh, K. P.; Kannan, L.; Daniel, M.; Misra, M. K.; Niphadkar, Madhura; Nagabhatla, Nidhi; Prasad, Nupoor; Tripathi, O. P.; Prasad, P. Rama Chandra; Dash, Pushpa; Qureshi, Qamer; Tripathi, S. K.; Ramesh, B. R.; Gowda, Balakrishnan; Tomar, Sanjay; Romshoo, Shakil; Giriraj, Shilpa; Ravan, Shirish A.; Behera, Soumit Kumar; Paul, Subrato; Das, Ashesh Kumar; Ranganath, B. K.; Singh, T. P.; Sahu, T. R.; Shankar, Uma; Menon, A. R. R.; Srivastava, Gaurav; Neeti; Sharma, Subrat; Mohapatra, U. B.; Peddi, Ashok; Rashid, Humayun; Salroo, Irfan; Krishna, P. Hari; Hajra, P. K.; Vergheese, A. O.; Matin, Shafique; Chaudhary, Swapnil A.; Ghosh, Sonali; Lakshmi, Udaya; Rawat, Deepshikha; Ambastha, Kalpana; Malik, Akhtar H.; Devi, B. S. S.; Gowda, Balakrishna; Sharma, K. C.; Mukharjee, Prashant; Sharma, Ajay; Davidar, Priya; Raju, R. R. Venkata; Katewa, S. S.; Kant, Shashi; Raju, Vatsavaya S.; Uniyal, B. P.; Debnath, Bijan; Rout, D. K.; Thapa, Rajesh; Joseph, Shijo; Chhetri, Pradeep; Ramachandran, Reshma M.
2015-07-01
A seamless vegetation type map of India (scale 1: 50,000) prepared using medium-resolution IRS LISS-III images is presented. The map was created using an on-screen visual interpretation technique and has an accuracy of 90%, as assessed using 15,565 ground control points. India has hitherto been using potential vegetation/forest type map prepared by Champion and Seth in 1968. We characterized and mapped further the vegetation type distribution in the country in terms of occurrence and distribution, area occupancy, percentage of protected area (PA) covered by each vegetation type, range of elevation, mean annual temperature and precipitation over the past 100 years. A remote sensing-amenable hierarchical classification scheme that accommodates natural and semi-natural systems was conceptualized, and the natural vegetation was classified into forests, scrub/shrub lands and grasslands on the basis of extent of vegetation cover. We discuss the distribution and potential utility of the vegetation type map in a broad range of ecological, climatic and conservation applications from global, national and local perspectives. We used 15,565 ground control points to assess the accuracy of products available globally (i.e., GlobCover, Holdridge's life zone map and potential natural vegetation (PNV) maps). Hence we recommend that the map prepared herein be used widely. This vegetation type map is the most comprehensive one developed for India so far. It was prepared using 23.5 m seasonal satellite remote sensing data, field samples and information relating to the biogeography, climate and soil. The digital map is now available through a web portal.
11. NatureServe International Ecological Classification Standard: Terrestrial Ecological Classifications of Vegetation Alliances and Associations at Prime Hook National Wildlife Refuge
US Fish and Wildlife Service, Department of the Interior — This subset of the International Ecological Classification Standard represents the National Vegetation Classification Standard NVCS and covers vegetation alliances...
12. [The meaning of vegetation classification for modern ecology].
Science.gov (United States)
Mirkin, B M; Martynenko, V B; Naumova, L G
2004-01-01
Eco-floristic classification (Brawn-Blanquet system) is useful since in similar manner it can establish ecological units of different level (syntaxons) that have high indicative value. Syntaxons can be used as markers of terrestrial ecosystems of different range. Although this system was proposed by analogy with plant taxonomy it reflects vegetation continuum. The application of this approach is based on certain standards and supported by developed software. The elements of arbitrariness in Brawn-Blanquet method are constrained by rules of strict recommendations. The method is considered as necessary in studies of biodiversity in protected areas. PMID:15125210
13. Next generation dynamic global vegetation models: learning from community ecology (Invited)
Science.gov (United States)
Scheiter, S.; Higgins, S.; Langan, L.
2013-12-01
Dynamic global vegetation models are a powerful tool to project past, current and future vegetation patterns and the associated biogeochemical cycles. However, most models are limited by their representation of vegetation by using static and pre-defined plant functional types and by their simplistic representation of competition. We discuss how concepts from community assembly theory and coexistence theory can help to improve dynamic vegetation models. We present a trait- and individual-based dynamic vegetation model, the aDGVM2, that allows individual plants to adopt a unique combination of trait values. These traits define how individual plants grow, compete and reproduce under the given biotic and abiotic conditions. A genetic optimization algorithm is used to simulate trait inheritance and reproductive isolation between individuals. These model properties allow the assembly of plant communities that are adapted to biotic and abiotic conditions. We show (1) that the aDGVM2 can simulate coarse vegetation patterns in Africa, (2) that changes in the environmental conditions and disturbances strongly influence trait diversity and the assembled plant communities by influencing traits such as leaf phenology and carbon allocation patterns of individual plants and (3) that communities do not necessarily return to the initial state when environmental conditions return to the initial state. The aDGVM2 deals with functional diversity and competition fundamentally differently from current models and allows novel insights as to how vegetation may respond to climate change. We believe that the aDGVM2 approach could foster collaborations between research communities that focus on functional plant ecology, plant competition, plant physiology and Earth system science.
14. Past and present vegetation ecology of Laetoli, Tanzania.
Science.gov (United States)
Andrews, Peter; Bamford, Marion
2008-01-01
We are attempting to set up a new protocol for palaeoecological reconstruction in relation to the fossil hominin site Laetoli, Tanzania. This is based on the premise that habitat variability in the past was at least as great as at present; that this variability at the landscape level is a function of variations in geology, soils, and topography rather than climate; and that vegetation type at the landscape level can be reconstructed from these environmental variables. Measurable variation in climate in tropical Africa today occurs over distances of at least 100 km, so that ranges of habitat variation within the limited area of Laetoli today can be reconstructed in relation to soils and topography, and the effects of climate changes are then estimated in relation to these other factors. In order to document the modern vegetation, we have made voucher collections of plants in the Laetoli region, recorded distributions of plants by habitat, climate, soil, and topography, and mapped the vegetation distributions. Results show that areas of low relief have soils with impeded drainage and dense Acacia drepanolobium woodland, having low canopies when disturbed by human action, higher when not; shallow brown soils on volcanic lavas have four woodland associations, two dominated by Acacia species, two by Combretum-Albizia species; shallow volcanic soils to the east have a woodland association with Croton-Dombeya-Albizia species; elevated land to the east on volcanic soils has two associations of montane-edge species, one with Croton-Celtis-Lepidotrichilia, and the other with Acacia lahai; the eastern highlands above 2,750 m have montane forest; seasonal water channels flowing from east to west have three Acacia riverine woodland associations; three deep valleys to the north of the area have dense riverine woodland with Celtis, Albizia, Euclea, Combretum, Acacia spp.; emergence of springs at Endulen feed a perennial stream with closed gallery forest with Ficus-Croton-Lepidotrichilia; and, finally, recent ash falls have produced immature alkaline soils with calcrete formation and short grass vegetation. All of these vegetation associations have been modified by human disturbance to greater or lesser degrees, and we have attempted to allow for this both by basing the associations on the least modified areas and by predicting how the associations, or parts of associations, have been altered by human action. Past land forms at Laetoli have been based on the geology and geomorphology of the area. Past vegetation patterns were estimated by superimposing present distributions of plant associations on equivalent landforms in the past, assuming similar climate to the present. This indicates the overall pattern of vegetation at Laetoli to have been a mosaic of low and tall deciduous woodlands and with riverine woodland and forest associations along water courses. Low woodlands would have been dominated by Acacia species, and tall woodlands by Combretum-Albizia species, with increasing increments of montane species, such as Croton species, to the east of the area. Riverine woodlands would have been dominated by Acacia-Euclea species, with wetter associations (downriver or linked with spring activity) supporting gallery forest with Ficus, Celtis, and Croton species. These are all species associations common in the area today, and with landforms little changed in the past, and assuming similar climate, there is every reason to predict that they would have been present in the past. Moreover, Pliocene environments lack the human disturbance that has destroyed much of the present day vegetation. Presence of woodlands is supported by fossil wood attributed to several of the tree species present in the area today and by similarities in the mammalian community structure between past and present. Having established the pattern for Pliocene vegetation based on climatic variables existing today, we then predict the effects of past variations in climate. PMID:17765945
15. Effects of aquatic vegetation type on denitrification
OpenAIRE
Veraart, A.J.; Bruijne, W.J.J., de; Peeters, E. T. H. M.; Klein, J.J.M., de; Scheffer, M.
2011-01-01
In a microcosm 15N enrichment experiment we tested the effect of floating vegetation (Lemna sp.) and submerged vegetation (Elodea nuttallii) on denitrification rates, and compared it to systems without macrophytes. Oxygen concentration, and thus photosynthesis, plays an important role in regulating denitrification rates and therefore the experiments were performed under dark as well as under light conditions. Denitrification rates differed widely between treatments, ranging from 2.8 to 20.9 ?...
16. Quantitative evaluation of regional vegetation ecological environment quality by using remotely sensed data over Qingjiang, Hubei
Science.gov (United States)
Wang, Cheng; Sun, Yan; Li, Lijun; Zhang, Qiuwen
2007-11-01
Vegetation cover is an important component and the best indication to the region ecological environment. The paper adopts a new method of integrating remote sensing technology and composite index appraisal model based multiple linear regression for quantitatively evaluating the regional vegetation ecological environment quality(VEEQ). This method is different to the traditional ecological environment research methods. It fully utilizes the advantages of quantitatively remote sensing technology, directly extracts the key influencing factors of VEEQ, such as vegetation indices (RVI, NDVI, ARVI, TMG), humidity indices(NDMI, MI, TMW), soil and landform indices(NDSI, TMB, GRABS) as the evaluating parameters from data the Landsat 5/TM remotely sensed images, and then puts these factors mentioned above into the multiple linear regression evaluating model. Ultimately we obtain the VEEQ evaluation rank figure of the experimental field-part of Qingjiang region. The handy multiple linear regression model, is proved to be well fit the experimental field for the vegetation ecological environment evaluation research.
17. Vegetation Classification, Ecological Integrity Assessment (EIA), Climate Change Vulnerability Assessment at Camas National Wildlife Refuge
US Fish and Wildlife Service, Department of the Interior — This project includes a pilot study to map the vegetation of Camas National Wildlife Refuge and a report on the overall ecological integrity of the refuge, how it...
18. Vegetation types and surface soils of the Idaho National Engineering Laboratory site
International Nuclear Information System (INIS)
In 1956 the newly formed Ecology Branch of the Atomic Energy Commission's (AEC) National Reactor Testing Station (NRTS), now called the Idaho National Engineering Laboratory (INEL), under the Department of Energy, initiated a project, using aerial photos taken in 1949, 1953, and 1954 to prepare a vegetation map of the site. This area was designated a National Environmental Research Park (NERP) in 1975. The first map prepared by N. R. French and Ray McBride was produced in 1958, and differentiated vegetation types on the basis of the two most prominent species of plants occurring in each type. This map gave adequate resolution between major vegetation types only in the complex mosaic of types at the northern end of the site, designating everything else as one homogeneous vegetation classification: Artemisia tridentata (big sagebrush) and Chrysothamnus viscidifluorus (green rabbitbrush). To improve the resolution of the vegetation map and thereby make it more useful in distinguishing habitats in all parts of the site, efforts were immediately begun to reclassify the vegetation types on the basis of the three (instead of two) most prominent species of plants representative of each type. This effort was continued on a low-priority basis for several years. In 1965 a vegetation map, according to the three species designation, was prepared by Ray McBride. The map was never documented in a formal report, but was reproduced in a thesis by Harniss (1968) and was referenced by H by Harniss (1968) and was referenced by Harniss and West (1973a) in their outline of the vegetation types of the NRTS. It is the purpose of this report to document the original vegetation type map prepared by the late Ray McBride and to provide general descriptions of the different vegetation types. The map has been revised and redrawn, and is appended to this report. Because vegetation is intimately related to soil development, a preliminary soil type map prepared and discussed by Adrian H. Dahl is included in this report
19. Future vegetation types and related main processes for Olkiluoto site
International Nuclear Information System (INIS)
This working report summarizes current knowledge of the land up-lift induced vegetation succession and future vegetation types on Olkiluoto Island and its surroundings. The report is based on generic literature and site-specific studies concerning Olkiluoto Island. Current vegetation on Olkiluoto Island and typical succession lines on different soil types are described, as well as main factors affecting the succession. Most relevant materials on hand are listed. Some problems and possible areas to be emphasized before using the data in modelling work are pointed out. (orig.)
20. The integration of GPS, vegetation mapping and GIS in ecological and behavioural studies
Scientific Electronic Library Online (English)
Steven Mark, Rutter.
2007-07-01
Full Text Available Global Positioning System (GPS) satellite navigation receivers are increasingly being used in ecological and behavioural studies to track the movements of animals in relation to the environments in which they live and forage. Concurrent recording of the animal's foraging behaviour (e.g. from jaw mov [...] ement recording) allows foraging locations to be determined. By combining the animal GPS movement and foraging data with habitat and vegetation maps using a Geographical Information System (GIS) it is possible to relate animal movement and foraging location to landscape and habitat features and vegetation types. This powerful approach is opening up new opportunities to study the spatial aspects of animal behaviour, especially foraging behaviour, with far greater precision and objectivity than before. Advances in GPS technology now mean that sub-metre precision systems can be used to track animals, extending the range of application of this technology from landscape and habitat scale to paddock and patch scale studies. As well as allowing ecological hypotheses to be empirically tested at the patch scale, the improvements in precision are also leading to the approach being increasing extended from large scale ecological studies to smaller (paddock) scale agricultural studies. The use of sub-metre systems brings both new scientific opportunities and new technological challenges. For example, fitting all of the animals in a group with sub-metre precision GPS receivers allows their relative inter-individual distances to be precisely calculated, and their relative orientations can be derived from data from a digital compass fitted to each receiver. These data, analyzed using GIS, could give new insights into the social behaviour of animals. However, the improvements in precision with which the animals are being tracked also needs equivalent improvements in the precision with which habitat and vegetation are mapped. This needs some degree of automation, as vegetation mapping at a fine spatial scale using the traditional manual approach is far too time consuming. This paper explores these issues, discussing new applications as well as approaches to overcoming some of the associated problems.
1. FRUIT AND VEGETABLE CONSUMPTION BY ECOLOGICAL ZONE AND SOCIOECONOMIC STATUS IN GHANA.
Science.gov (United States)
2015-09-01
The disease burden in both developed and developing countries is moving towards higher proportions of chronic diseases, and diseases such as cancers are now considered to be of public health concern. In sub-Saharan Africa, healthy behaviours such as fruit and vegetable consumption are recommended to reduce the chances of onset of chronic diseases. This paper examines the determinants of fruit and vegetable consumption in Ghana with particular emphasis on consumption by ecological zone. Data were from the 2008 Ghana Demographic and Health Survey (n=4916 females; n=4568 males). Univariate and multivariate analyses were performed using basic descriptive and Poisson regression. The main independent variable was ecological zone and the dependent variables were levels of fruit and vegetable consumption. The mean number of fruits and vegetables consumed in a week was higher among females (fruits: 7.5, 95% CI=7.3-7.7; vegetables: 8.1, 95% CI=7.8-8.3) than males (fruits: 6.2, 95% CI=6.0-6.4; vegetables: 7.9, 95% CI=7.7-8.2). There were significant differences in consumption by ecological zone. Respondents in the Savannah zone consumed less fruit than those in the Coastal and Forest zones, but the differences in fruit and vegetable consumption between the Coastal and Savannah zones were not consistent, especially for vegetable consumption. The findings suggest that one of the key interventions to improve fruit and vegetable consumption could lie in improving distribution systems since their consumption is significantly higher in the Forest zone, where the production of fruit and vegetables is more developed than in the Savannah and Coastal zones. The findings relating to household wealth challenge conventional knowledge on fruit and vegetable consumption, and rather argue for equal consideration of spatial differences in critical health outcomes. PMID:24991697
2. Alternatives to sowing vegetable type soybeans
OpenAIRE
Edcarlos Mannfredini; Deonisio Destro; Martin Homechin; Gustavo Sachsida; Édison Miglioranza
1998-01-01
Today, soybean crops of the Tamba Kurodaisu cultivar are sown in beds prior to transplantation to the field. This planting system has caused crop failure due to damage to the root system. An experiment to test different sowing alternatives to obtain plantlets for cropping of food type big seeded soybean was set up with the following treatments: sowing in beds; sowing in 130 cm³ newspaper cups; sowing in test tubes of volumes of 30 cm³, 60 cm³ and 70 cm³; sowing in 70 cm³ disposable plastic cu...
3. Palaeo plant diversity in subtropical Africa - ecological assessment of a conceptual model of climate-vegetation interaction
Science.gov (United States)
Groner, V. P.; Claussen, M.; Reick, C.
2015-07-01
We here critically re-assess a conceptual model dealing with the potential effect of plant diversity on climate-vegetation feedback, and provide an improved version adjusted to plant types that prevailed during the African Humid Period (AHP). Our work contributes to the understanding of the timing and abruptness of vegetation decline at the end of the AHP, investigated by various working groups during the past two decades using a wide range of model and palaeoproxy reconstruction approaches. While some studies indicated an abrupt collapse of vegetation at the end of the AHP, others suggested a gradual decline. Claussen et al. (2013) introduced a new aspect in the discussion, proposing that plant diversity in terms of moisture requirements could affect the strength of climate-vegetation feedback. In a conceptual model study, the authors illustrated that high plant diversity could stabilize an ecosystem, whereas a reduction in plant diversity might allow for an abrupt regime shift under gradually changing environmental conditions. Based on recently published pollen data and the current state of ecological literature, we evaluate the representation of climate-vegetation feedback in this conceptual approach, and put the suggested conclusions into an ecological context. In principle, the original model reproduces the main features of different plant types interacting together with climate although vegetation determinants other than precipitation are neglected. However, the model cannot capture the diversity of AHP vegetation. Especially tropical gallery forest taxa, indirectly linked to local precipitation, are not appropriately represented. In order to fill the gaps in the description of plant types regarding AHP diversity, we modify the original model in four main aspects. First, the growth ranges in terms of moisture requirements are extended by upper limits to represent full environmental envelopes. Second, data-based AHP plant types replace the hypothetical plant types. Third, the tropical gallery forest type follows the gradual insolation forcing with a linear approximation because it relies more on large scale climate than on regional precipitation amounts. Fourth, we replace the dimensionless vegetation cover fractions with individual effective leaf areas to capture different contributions to climate-vegetation feedback. These adjustments allow for the consideration of a broader spectrum of plant types, plant-climate feedbacks, and implicitly for plant-plant interactions. With the consideration of full environmental envelopes and the prescribed retreat of the tropical gallery forest type we can simulate a diverse mosaic-like environment as it was reconstructed from pollen. Transient simulations of this diverse environment support the buffering effect of high functional diversity on ecosystem performance and precipitation, concluded by Claussen et al. (2013) from the simple approach. Sensitivity studies with different combinations of plant types highlight the importance of plant composition on system stability, and the stabilizing or destabilizing potential a single functional type may inherit. In a broader view, the adjusted model provides a useful tool to study the roles of real plant types in an ecosystem and their combined climate-vegetation feedback under changing precipitation regimes.
4. Palaeo plant diversity in subtropical Africa – ecological assessment of a conceptual model of climate–vegetation interaction
Directory of Open Access Journals (Sweden)
V. P. Groner
2015-07-01
Full Text Available We here critically re-assess a conceptual model dealing with the potential effect of plant diversity on climate–vegetation feedback, and provide an improved version adjusted to plant types that prevailed during the African Humid Period (AHP. Our work contributes to the understanding of the timing and abruptness of vegetation decline at the end of the AHP, investigated by various working groups during the past two decades using a wide range of model and palaeoproxy reconstruction approaches. While some studies indicated an abrupt collapse of vegetation at the end of the AHP, others suggested a gradual decline. Claussen et al. (2013 introduced a new aspect in the discussion, proposing that plant diversity in terms of moisture requirements could affect the strength of climate–vegetation feedback. In a conceptual model study, the authors illustrated that high plant diversity could stabilize an ecosystem, whereas a reduction in plant diversity might allow for an abrupt regime shift under gradually changing environmental conditions. Based on recently published pollen data and the current state of ecological literature, we evaluate the representation of climate–vegetation feedback in this conceptual approach, and put the suggested conclusions into an ecological context. In principle, the original model reproduces the main features of different plant types interacting together with climate although vegetation determinants other than precipitation are neglected. However, the model cannot capture the diversity of AHP vegetation. Especially tropical gallery forest taxa, indirectly linked to local precipitation, are not appropriately represented. In order to fill the gaps in the description of plant types regarding AHP diversity, we modify the original model in four main aspects. First, the growth ranges in terms of moisture requirements are extended by upper limits to represent full environmental envelopes. Second, data-based AHP plant types replace the hypothetical plant types. Third, the tropical gallery forest type follows the gradual insolation forcing with a linear approximation because it relies more on large scale climate than on regional precipitation amounts. Fourth, we replace the dimensionless vegetation cover fractions with individual effective leaf areas to capture different contributions to climate–vegetation feedback. These adjustments allow for the consideration of a broader spectrum of plant types, plant-climate feedbacks, and implicitly for plant-plant interactions. With the consideration of full environmental envelopes and the prescribed retreat of the tropical gallery forest type we can simulate a diverse mosaic-like environment as it was reconstructed from pollen. Transient simulations of this diverse environment support the buffering effect of high functional diversity on ecosystem performance and precipitation, concluded by Claussen et al. (2013 from the simple approach. Sensitivity studies with different combinations of plant types highlight the importance of plant composition on system stability, and the stabilizing or destabilizing potential a single functional type may inherit. In a broader view, the adjusted model provides a useful tool to study the roles of real plant types in an ecosystem and their combined climate–vegetation feedback under changing precipitation regimes.
5. Evaluation of Polarimetric SAR Decomposition for Classifying Wetland Vegetation Types
Directory of Open Access Journals (Sweden)
Sang-Hoon Hong
2015-07-01
Full Text Available The Florida Everglades is the largest subtropical wetland system in the United States and, as with subtropical and tropical wetlands elsewhere, has been threatened by severe environmental stresses. It is very important to monitor such wetlands to inform management on the status of these fragile ecosystems. This study aims to examine the applicability of TerraSAR-X quadruple polarimetric (quad-pol synthetic aperture radar (PolSAR data for classifying wetland vegetation in the Everglades. We processed quad-pol data using the Hong & Wdowinski four-component decomposition, which accounts for double bounce scattering in the cross-polarization signal. The calculated decomposition images consist of four scattering mechanisms (single, co- and cross-pol double, and volume scattering. We applied an object-oriented image analysis approach to classify vegetation types with the decomposition results. We also used a high-resolution multispectral optical RapidEye image to compare statistics and classification results with Synthetic Aperture Radar (SAR observations. The calculated classification accuracy was higher than 85%, suggesting that the TerraSAR-X quad-pol SAR signal had a high potential for distinguishing different vegetation types. Scattering components from SAR acquisition were particularly advantageous for classifying mangroves along tidal channels. We conclude that the typical scattering behaviors from model-based decomposition are useful for discriminating among different wetland vegetation types.
6. ECOLOGICAL CONTROL EQUIPMENT AND TECHNOLOGY OF UNDERWATER VEGETATION DEVELOPMENT
Directory of Open Access Journals (Sweden)
V. TITINSCHNEIDER
2013-12-01
Full Text Available The excess of aquatic submerse vegetation development carries to the reduction of the real rearing area for the piscicultural material from the production farms and allow nestling of the ichthyophages bird species that decrease the fish production. Aquatic submerse vegetation stumble the utilization of aquatic zones for recreation and also wright function of basins utilized for the electric energy production, of micro electricity works through obstruction of the dams grid. The control of the aquatic submerse vegetation development, for Myriophyllum verticillatum, Ceratophyllum submersum, Urticularia vulgaris, Potamogeton natans, Nimphoides peltata species it is accomplish through the removing of some parts of these, preferably with all the stump system. Usually, these its accomplish with the floating equipments fit up with the thermic engines and the propulsion and governating elements who have harm over the fish and some others aquatic organisms through the noise, the displacing a large quality of water caused of propulsion systems and through the noxes elimination (flue, carburant trails, etc.. These technologies reside from the evacuation of the aquatic submerse vegetation and the stump systems of these with the help of an adjustable rake, hang up from the coast by a rope, wrapped to a drummer, who is trained by a motto-propeller group with a small installed power.
7. Vegetation change: a reunifying concept in plant ecology.
Czech Academy of Sciences Publication Activity Database
Davis, M. A.; Pergl, Jan; Truscott, A.; Kollmann, J.; Bakker, J. P.; Domenech, R.; Prach, Karel; Prieur-Richard, A.; Veeneklaas, R. M.; Pyšek, Petr; del Moral, R.; Hobbs, R. J.; Collins, S. L.; Pickett, S. T. A.; Reich, P. B.
2005-01-01
Ro?. 7, - (2005), s. 69-76. ISSN 1433-8319 R&D Projects: GA ?R(CZ) GA206/02/0617 Institutional research plan: CEZ:AV0Z60050516 Keywords : vegetation succession * climate change * plant invasions Subject RIV: EF - Botanics Impact factor: 3.053, year: 2005
8. Vegetation
DEFF Research Database (Denmark)
Epstein, H.E.; Walker, D.A.
2012-01-01
• Over the past 30 years (1982-2011), the Normalized Difference Vegetation Index (NDVI), an index of green vegetation, has increased 15.5% in the North American Arctic and 8.2% in the Eurasian Arctic. In the more southern regions of Arctic tundra, the estimated aboveground plant biomass has increased 20-26%. • Increasing shrub growth and range extension throughout the Low Arctic are related to winter and early growing season temperature increases. Growth of other tundra plant types, including graminoids and forbs, is increasing, while growth of mosses and lichens is decreasing. • Increases in vegetation (including shrub tundra expansion) and thunderstorm activity, each a result of Arctic warming, have created conditions that favor a more active Arctic fire regime.
9. LBA-ECO LC-15 Vegetation Cover Types from MODIS, 1-km, Amazon Basin: 2000-2001
National Aeronautics and Space Administration — ABSTRACT: This data set contains proportional estimates for the vegetative cover types of woody vegetation, herbaceous vegetation, and bare ground over the Amazon...
10. Vegetation, population and ecological track as sustainability indicators in Colombia
International Nuclear Information System (INIS)
Biophysical sustainability, namely natural capabilities to sustain human development in Colombia, is explored through environmental indicators based on land cover and demographic variables. Remnant vegetation index (IVR in Spanish) uses cover as a measure of ecosystem functionality. Population pressure index (IPD) applies population density to environmental demand analysis. Footprint index (IHE) relates the inverse of density with sustainability. Environmental criticality index combines IVR and IPD to detect offer/demand unbalances. Results suggest Colombia is sustainable although many places in it could be in danger; this could be related with social and economical features of the country
11. Qualitative parameters of non-traditional types of vegetables
Directory of Open Access Journals (Sweden)
Eva Kudrná?ová
2015-08-01
Full Text Available The main aim of this study was to determine selected quality indicators of non-traditional types of leafy vegetables. Mizuna (Brassica rapa japonica, Chinese mustard (Brassica juncea, edible chrysanthemum (Chrysanthemum coronarium and arugula (Eruca sativa belonged among the selected species of vegetables. During the one-year experiment, spring and autumn sowing was carried out for these species of vegetables. The measured quality parameters were the content of nitrates and ascorbic acid. Sampling was done in the morning and in the laboratory, the samples were further processed according to the type of determination. To determine the content of nitrates and ascorbic acid, leaves were removed from plants. The filtrate from the leaves was then prepared. Determination of nitrates and ascorbic acid was carried out using a special test strip and device Rqflex plus 10. The results of measurement of both sowing varieties were compared. Total nitrate content was higher up to 22% in plants sown in the autumn except edible chrysanthemum (Chrysanthemum coronarium. The highest content was recorded in arugula (Eruca sativa, which was recently implemented to the studies of the European Union and for which there were set the limits of nitrates. Overall, the nitrate content ranged from 221 to 334 ppm in spring varieties and from 249 to 384 mg/kg in autumn varieties. Ascorbic acid content was very high in Chinese mustard (Brassica juncea, edible chrysanthemum (Chrysanthemum coronarium and arugula (Eruca sativa in both spring and autumn varieties. Values of ascorbic acid ranged from 839 in autumn sowing up to 2909 mg/kg in spring sowing. These non-traditional types of leafy vegetables could be included among the other importants sources of vitamin C in the future.
12. Sampling design in large-scale vegetation studies: Do not sacrifice ecological thinking to statistical purism!.
Czech Academy of Sciences Publication Activity Database
Role?ek, J.; Chytrý, M.; Hájek, Michal; Lvon?ík, S.; Tichý, L.
2007-01-01
Ro?. 42, - (2007), s. 199-208. ISSN 1211-9520 R&D Projects: GA AV ?R IAA6163303; GA ?R(CZ) GA206/05/0020 Grant ostatní: GA AV ?R(CZ) KJB601630504 Institutional research plan: CEZ:AV0Z60050516 Keywords : Ecological methodology * Large-scale vegetation patterns * Macroecology Subject RIV: EF - Botanics Impact factor: 1.133, year: 2007
13. Comparison of total polyphenol contents And antioxidant activity in cruciferous vegetables grown in diversified ecological conditions
Directory of Open Access Journals (Sweden)
Joanna Kapusta-Duch
2012-12-01
Full Text Available Background.The aim of this study was to compare total polyphenol contents and antioxidant activity of three species of cruciferous vegetables grown under diversified ecological conditions for three consecutive years. Material and methods. Methanol extracts were prepared to be used to determine (spectrometrically the content of total phenolics, using the Folin-Ciocalteau reagent and antioxidant activity by identifying the sam- ple’s ability to extinguish an ABTS•+free radical. Results.All these species of cruciferous vegetables contained similar total polyphenols amounts regardless of its origin. Only red cabbage from organic farms was characterized by significantly higher antioxidant activity compared to vegetables purchased from local retailers in Cracow and similar or those cultivated near the steelworks. In white cabbage from farms located in a former steelworks protection zone a higher antioxidant activity was found than in organically grown vegetables and similar to that in vegetables available in retail. Brussels sprouts was characterised by a similar antioxidant activity regardless of its origin. Conclusions. On the basis of the present study, it cannot be concluded that organically grown cruciferous vegetables generally have higher contents of health-promoting secondary metabolites in comparison with the conventionally cultivated ones.
14. Weed vegetation ecology of arable land in Salalah, Southern Oman
OpenAIRE
El-Sheikh, Mohamed A.
2013-01-01
This paper applies multivariate statistical methods to a data set of weed relevés from arable fields in two different habitat types of coastal and mountainous escarpments in Southern Oman. The objectives were to test the effect of environmental gradients, crop plants and time on weed species composition, to rank the importance of these particular factors, and to describe the patterns of species composition and diversity associated with these factors. Through the application of TWINSPAN, DCA a...
15. Ecological Land Type Associations of Minnesota
Minnesota Department of Natural Resources — This coverage provides information for the fourth level of the Ecological Classification System. Polygon boundaries were delineated at a scale of 1:100,000 with a...
16. Colored Noises-Induced Regime Shifts in a Vegetation Ecological System
Science.gov (United States)
Han, Qing-Lin; Zeng, Jia-Kui; Yang, Tao; Zhang, Chun; Long, Fei; Fu, Yun-Chang; Zeng, Chun-Hua
2015-08-01
In this paper, we investigate the stationary probability distribution and mean first passage time in a vegetation ecological system, which is driven by cross-correlation between intrinsic and extrinsic colored noises as well as the nonzero cross-correlation in between. The impacts of the self-correlation time ?1 and ?2, the cross-correlation time ?3 and intensity k on the stationary probability distribution and mean first passage time are discussed, respectively. Our main results show that: (i) the self-correlation time ?1 can induce regime shifts from the desert state to the sustainable vegetation state, while the self-correlation time ?2, cross-correlation time ?3 and intensity k can induce regime shifts from the sustainable vegetation state to the desert state; and (ii) the self-correlation time ?1 or ?2 can enhance the stability of the sustainable vegetation biomass, while the cross-correlation time ?3 or strength k weakens the stability of the sustainable vegetation biomass. Supported by the National Natural Science Foundation of China under Grant No. 11305079, and the Introduction of Talent Capital Group Fund Project of Kunming University of Science and Technology under Grant No. KKZ3201407030
17. Weed vegetation ecology of arable land in Salalah, Southern Oman.
Science.gov (United States)
El-Sheikh, Mohamed A
2013-07-01
This paper applies multivariate statistical methods to a data set of weed relevés from arable fields in two different habitat types of coastal and mountainous escarpments in Southern Oman. The objectives were to test the effect of environmental gradients, crop plants and time on weed species composition, to rank the importance of these particular factors, and to describe the patterns of species composition and diversity associated with these factors. Through the application of TWINSPAN, DCA and CCA programs on data relating to 102 species recorded in 28 plots and farms distributed in the study area, six plant communities were identified: I- Dichanthium micranthum, II- Cynodon dactylon-D. micranthum, III- Convolvulus arvensis, IV- C. dactylon-Sonchus oleraceus, V- Amaranthus viridis and VI- Suaeda aegyptiaca-Achyranthes aspera. The ordination process (CCA) provided a sequence of plant communities and species diversity that correlated with some anthropogenic factors, physiographic variables and crop types. Therefore, length of time since farm construction, disturbance levels and altitude are the most important factors related to the occurrence of the species. The perennial species correlated with the more degraded mountain areas of new farm stands, whereas most of the annuals correlated with old lowland and less disturbed farms. PMID:23961246
18. Using ecological forecasting of future vegetation transition and fire frequency change in the Sierra Nevada to assess fire management strategies
Science.gov (United States)
Thorne, J. H.; Schwartz, M. W.; Holguin, A. J.; Moritz, M.; Batllori, E.; Folger, K.; Nydick, K.
2013-12-01
Ecological systems may respond in complex manners as climate change progresses. Among the responses, site-level climate conditions may cause a shift in vegetation due to the physiological tolerances of plant species, and the fire return interval may change. Natural resource managers challenged with maintaining ecosystem health need a way to forecast how these processes may affect every location, in order to determine appropriate management actions and prioritize locations for interventions. We integrated climate change-driven vegetation type transitions with projected change in fire frequency for 45,203 km2 of the southern Sierra Nevada, California, containing over 10 land management agencies as well as private lands. This Magnitude of Change (MOC) approach involves classing vegetation types in current time according to their climate envelopes, and identifying which sites will in the future have climates beyond what that vegetation currently occurs in. Independently, fire models are used to determine the change in fire frequency for each site. We examined 82 vegetation types with >50 grid cell occurrences. We found iconic resources such as the giant sequoia, lower slope oak woodlands, and high elevation conifer forests are projected as highly vulnerable by models that project a warmer drier future, but not as much by models that project a warmer future that is not drier than current conditions. Further, there were strongly divergent vulnerabilities of these forest types across land ownership (National Parks versus US Forest Service lands), and by GCM. For example, of 50 giant sequoia (Sequoiadendron giganteum) groves and complexes, all but 3 (on Sierra National Forest) were in the 2 highest levels of risk of climate and fire under the GFDL A2 projection, while 15 groves with low-to-moderate risk were found on both the National Parks and National Forests 18 in the 2 under PCM A2. Landscape projections of potential MOC suggest that the region is likely to experience strong upslope shifting of open grassland, chaparral and hardwood types, which may be initiated by increased fire frequencies, particularly where fires have not recently burned within normal fire recurrence interval departures (FRID). An evaluation of four fire management strategies (business as usual; resist change; foster orderly change; protect vital resources) across four combinations of future climate and fire frequency found that no single management strategy was uniformly successful in protecting critical resources across the range of future conditions examined. This limitation is somewhat driven by current management constraints on the amount of management available to resource managers, which suggests management will need to use a triage approach to application of proactive fire management strategies, wherein MOC landscape projections can be used in decision support.
19. Vegetation types and climate conditions reflected by the modern phytolith assemblages in the subalpine Dalaoling Forest Reserve, central China
Science.gov (United States)
Traoré, Djakanibé Désiré; Gu, Yansheng; Liu, Humei; Shemsanga, Ceven; Ge, Jiwen
2015-06-01
This research describes modern phytolith records and distributions from subalpine surface soils in the Dalaoling Forest Reserve, and reveals its implications for local climate conditions with respect to the altitude gradient. Well-preserved phytolith morpho-types, assemblages, and climatic indices were used to study the relationship between local vegetation and climate conditions. The phytolith classification system is mainly based on the characteristics of detailed morpho-types described for anatomical terms, which are divided into seven groups: long cells, short cells, bulliform cells, hair cells, pteridophyte type, broad-leaved type, and gymnosperm type. Phytoliths originating from the Poaceae are composed of Pooideae (rondel and trapeziform), Panicoideae (bilobate, cross, and polylobate), Chloridoideae (short/square saddle), and Bambusoideae (oblong concave saddle). Based on the altitudinal distribution of the phytolith assemblages and the indices of aridity (Iph), climate (Ic), and tree cover density (D/P), five phytolith assemblage zones have revealed the five types of climatic conditions ranging from 1,169 m to 2,005 m in turn: warm-wet, warm-xeric to warm-mesic, warm-xeric to cool-mesic, cool-xeric, and cool-mesic to cool-xeric. The Bambusoideae, Panicoideae, and Chloridoideae are the dominant vegetation at the lower-middle of the mountains, while Pooideae is mainly distributed in the higher mountains. The close relationship between phytolith assembleages and changes of altitude gradient suggest that vegetation distribution patterns and plant ecology in the Dalaoling mountains are controlled by temperature and humidity conditions. Our results highlight the importance of phytolith records as reliable ecoclimatic indicators for vegetation ecology in subtropical regions.
20. Forests, savannas, and grasslands: bridging the knowledge gap between ecology and Dynamic Global Vegetation Models
Science.gov (United States)
Baudena, M.; Dekker, S. C.; van Bodegom, P. M.; Cuesta, B.; Higgins, S. I.; Lehsten, V.; Reick, C. H.; Rietkerk, M.; Scheiter, S.; Yin, Z.; Zavala, M. A.; Brovkin, V.
2015-03-01
The forest, savanna, and grassland biomes, and the transitions between them, are expected to undergo major changes in the future due to global climate change. Dynamic global vegetation models (DGVMs) are very useful for understanding vegetation dynamics under the present climate, and for predicting its changes under future conditions. However, several DGVMs display high uncertainty in predicting vegetation in tropical areas. Here we perform a comparative analysis of three different DGVMs (JSBACH, LPJ-GUESS-SPITFIRE and aDGVM) with regard to their representation of the ecological mechanisms and feedbacks that determine the forest, savanna, and grassland biomes, in an attempt to bridge the knowledge gap between ecology and global modeling. The outcomes of the models, which include different mechanisms, are compared to observed tree cover along a mean annual precipitation gradient in Africa. By drawing on the large number of recent studies that have delivered new insights into the ecology of tropical ecosystems in general, and of savannas in particular, we identify two main mechanisms that need improved representation in the examined DGVMs. The first mechanism includes water limitation to tree growth, and tree-grass competition for water, which are key factors in determining savanna presence in arid and semi-arid areas. The second is a grass-fire feedback, which maintains both forest and savanna presence in mesic areas. Grasses constitute the majority of the fuel load, and at the same time benefit from the openness of the landscape after fires, since they recover faster than trees. Additionally, these two mechanisms are better represented when the models also include tree life stages (adults and seedlings), and distinguish between fire-prone and shade-tolerant forest trees, and fire-resistant and shade-intolerant savanna trees. Including these basic elements could improve the predictive ability of the DGVMs, not only under current climate conditions but also and especially under future scenarios.
1. Effects of Mixing Interaction Types on Ecological Community Stability
CERN Document Server
Suweis, Samir; Maritan, Amos
2013-01-01
In the last years, a remarkable theoretical effort has been made in order to understand stability and complexity in ecological communities. The non-random structures of real ecological interaction networks has been recognized as one key ingredient contributing to the coexistence between high complexity and stability in real ecosystems. However most of the theoretical studies have considered communities with only one interaction type (either antagonistic, competitive, or mutualistic). Recently it has been proposed a theoretical analysis on multiple interaction types in ecological systems, concluding that: a) Mixture of antagonistic and mutualistic interactions stabilize the system with respect to the less realistic case of only one interaction type; b) Complexity, measured in terms of the number of interactions and the number of species, increases stability in systems with different types of interactions. By introducing new theoretical investigations and analyzing 21 empirical data sets representing mutualisti...
2. Categorizing Grassland Vegetation with Full-Waveform Airborne Laser Scanning: A Feasibility Study for Detecting Natura 2000 Habitat Types
Directory of Open Access Journals (Sweden)
András Zlinszky
2014-08-01
Full Text Available There is increasing demand for reliable, high-resolution vegetation maps covering large areas. Airborne laser scanning data is available for large areas with high resolution and supports automatic processing, therefore, it is well suited for habitat mapping. Lowland hay meadows are widespread habitat types in European grasslands, and also have one of the highest species richness. The objective of this study was to test the applicability of airborne laser scanning for vegetation mapping of different grasslands, including the Natura 2000 habitat type lowland hay meadows. Full waveform leaf-on and leaf-off point clouds were collected from a Natura 2000 site in Sopron, Hungary, covering several grasslands. The LIDAR data were processed to a set of rasters representing point attributes including reflectance, echo width, vegetation height, canopy openness, and surface roughness measures, and these were fused to a multi-band pseudo-image. Random forest machine learning was used for classifying this dataset. Habitat type, dominant plant species and other features of interest were noted in a set of 140 field plots. Two sets of categories were used: five classes focusing on meadow identification and the location of lowland hay meadows, and 10 classes, including eight different grassland vegetation categories. For five classes, an overall accuracy of 75% was reached, for 10 classes, this was 68%. The method delivers unprecedented fine resolution vegetation maps for management and ecological research. We conclude that high-resolution full-waveform LIDAR data can be used to detect grassland vegetation classes relevant for Natura 2000.
3. Vegetation Dynamics Depending on Ecological Particularities of Bozanta Mare (Maramures County-Romania) Tailing Pound. Case Study
OpenAIRE
Monica Marian; Leonard M. Cozmuta; Camelia Varga; Anca M. Cozmuta; Eugen Nour
2009-01-01
The present study follows an ecological demarch of reintegration in the scenary through revegetation of an anthropic ground, consisting in a waste pond formed from the flotation activity of non-ferrous ores. Problem statement: To support the formation of a compact vegetal layer, having an anti-errosion and a restoration role, a preliminary study was required regarding the spontaneous settlement of different vegetal species. We have followed the specific floristic composition and the biodivers...
4. LBA-ECO LC-15 Vegetation Cover Types from MODIS, 1-km, Amazon Basin: 2000-2001
National Aeronautics and Space Administration — This data set contains proportional estimates for the vegetative cover types of woody vegetation, herbaceous vegetation, and bare ground over the Amazon Basin for...
5. Effect of eating vegetables before carbohydrates on glucose excursions in patients with type 2 diabetes
OpenAIRE
Imai, Saeko; Fukui, Michiaki; Kajiyama, Shizuo
2013-01-01
The aim of this review was to evaluate whether eating vegetables before carbohydrates could reduce the postprandial glucose, insulin, and improve long-term glycemic control in Japanese patients with type 2 diabetes. We studied the effect of eating vegetables before carbohydrates on postprandial plasma glucose, insulin, and glycemic control for 2.5 y in patients with type 2 diabetes. The postprandial glucose and insulin levels decreased significantly when the patients ate vegetables before car...
6. Vegetation geographical patterns as a key to the past, with emphasis on the dry vegetation types of South Africa
Directory of Open Access Journals (Sweden)
M. J. A. Werger
1983-12-01
Full Text Available Southern Africa is characterized by a highly diversified vegetational cover with extremes as contrasting as desert, tropical forest, alpine grassland, or mediterranean type scrub, and many other types in between. This vegetational pattern is strongly correlated to the climatological pattern. It is therefore likely that past changes in climate can still be partly traced in the vegetational pattern, particularly in geographical anomalies, and that study of these patterns provides complementary evidence to palynological research. The following anomalies in the vegetational pattern are briefly discussed: 1. island-wise occurrence of Afro-montane vegetation on mesic, sheltered sites in the southern Sudano- Zambezian Region, in particular in the Highveld grassland/False Karoo transition area; 2. similar westward occurrence of Sudano-Zambezian scrub patches in the Karoo-Namib Region near the Orange/Vaal confluence; 3. scattered occurrence of Sudano-Zambezian woody species in a matrix of Karoo-Namib vegetation in the marginal Karoo-Namib Region; 4. island-wise occurrence of frost-tolerant, dry, karroid dwarf shrub vegetation of predominantly C,-plants on isolated peaks in the winter rainfall area of Namaqualand; 5. peculiar patchy distribution of some succulents in wide areas of climatically rather homogeneous, succulent dwarf shrub vegetation of predominantly CAM-plants in the escarpment area of Namaqualand. a pattern reminiscent of that in many Cape fynbos species. Interpretation of these patterns logically leads to the conclusion that these result from a previously wetter, a previously cooler, or a previously wetter and cooler climate, respectively, over the parts of southern Africa under discussion. This conclusion is compared with published palynological views.
7. Plant physiological ecology and the global changes Ecofisiologia vegetal e as mudanças globais
Directory of Open Access Journals (Sweden)
João Paulo Rodrigues Alves Delfino Barbosa
2012-06-01
8. Vertical and Horizontal Vegetation Structure across Natural and Modified Habitat Types at Mount Kilimanjaro
Science.gov (United States)
Rutten, Gemma; Ensslin, Andreas; Hemp, Andreas; Fischer, Markus
2015-01-01
In most habitats, vegetation provides the main structure of the environment. This complexity can facilitate biodiversity and ecosystem services. Therefore, measures of vegetation structure can serve as indicators in ecosystem management. However, many structural measures are laborious and require expert knowledge. Here, we used consistent and convenient measures to assess vegetation structure over an exceptionally broad elevation gradient of 866–4550m above sea level at Mount Kilimanjaro, Tanzania. Additionally, we compared (human)-modified habitats, including maize fields, traditionally managed home gardens, grasslands, commercial coffee farms and logged and burned forests with natural habitats along this elevation gradient. We distinguished vertical and horizontal vegetation structure to account for habitat complexity and heterogeneity. Vertical vegetation structure (assessed as number, width and density of vegetation layers, maximum canopy height, leaf area index and vegetation cover) displayed a unimodal elevation pattern, peaking at intermediate elevations in montane forests, whereas horizontal structure (assessed as coefficient of variation of number, width and density of vegetation layers, maximum canopy height, leaf area index and vegetation cover) was lowest at intermediate altitudes. Overall, vertical structure was consistently lower in modified than in natural habitat types, whereas horizontal structure was inconsistently different in modified than in natural habitat types, depending on the specific structural measure and habitat type. Our study shows how vertical and horizontal vegetation structure can be assessed efficiently in various habitat types in tropical mountain regions, and we suggest to apply this as a tool for informing future biodiversity and ecosystem service studies. PMID:26406985
9. Masking Vegetable Bitterness to Improve Palatability Depends on Vegetable Type and Taste Phenotype
OpenAIRE
Sharafi, Mastaneh; Hayes, John E; Duffy, Valerie B
2012-01-01
Consumption of dark green vegetables falls short of recommendations, in part, because of unpleasant bitterness. A laboratory-based study of 37 adults was used to determine bitter and hedonic responses to vegetables (asparagus, Brussels sprouts, kale) with bitter masking agents (1.33 M sodium acetate, 10 and 32 mM sodium chloride, and 3.2 mM aspartame) and then characterized by taste phenotype and vegetable liking. In repeated-measures ANOVA, aspartame was most effective at suppressing bittern...
10. IDENTITIES AND ECOLOGICAL ASPECTS OF PHYTOPLASMAS ASSOCIATED WITH AN ASTER YELLOWS EPIDEMIC IN VARIABLE VEGETABLE CROPS IN TEXAS
Science.gov (United States)
In 2000, an outbreak of aster yellows in carrots occurred in southwestern Texas. An epidemiological survey indicated that several vegetable crops including cabbage, onion, parsley and dill, and some weeds were also infected by aster yellows phytoplasmas. Ecological aspects of phytoplasmas involved ...
11. Assessing Vegetation Cover Dynamics Induced by Policy-Driven Ecological Restoration and Implication to Soil Erosion in Southern China
Science.gov (United States)
Zhang, Jien; Wang, Tianming; Ge, Jianping
2015-01-01
In the aftermath of the severe droughts and floods at the end of the 20th century, the Chinese government launched several ecological restoration projects, including the Natural Forest Protection Program in 1998 and the Grain-for-Green Program in 1999, to promote afforestation and reforestation to reduce surface runoff and consequent soil erosion nationwide. However, it is still unclear how vegetation has changed in southern China since the launch of these programs. In this study, we used the MODIS Enhanced Vegetation Index (EVI) to analyze the vegetation cover dynamics in southern China from 2000 to 2009 and evaluate the resulting effects of controlling soil erosion. Our observations indicate that 5.3% of the study area significantly increased and 0.98% significantly decreased in EVI value (p < 0.05). The spring EVI had largest increase in space. The conversions of croplands on steep slopes to forests resulting from national policies led to significant increases in EVI. The increase in EVI was not driven by annual average temperature and annual precipitation. By referencing ecological restoration statistical data and field observations, we showed that ecological restoration programs significantly improved vegetation cover in southern China. Increase in the area of farmland-converted forestlands has reduced soil erosion based upon monitoring sediment yields at hydrologic stations in the Yangtze River. This study displays the spatial patterns of trend in vegetation growth since the beginning of the 21st century in southern China and highlights the important role of China’s afforestation program. PMID:26115116
12. Measurement and modelling of evapotranspiration in three fynbos vegetation types
Scientific Electronic Library Online (English)
S, Dzikiti; NZ, Jovanovic; R, Bugan; S, Israel; DC, Le Maitre.
2014-04-03
Full Text Available Many studies have investigated the water relations of indigenous plants in the fynbos shrublands of the Cape, South Africa. These have mainly focused on understanding the mechanisms by which individual plant species respond to droughts, the frequency and severity of which is expected to increase due [...] to climate change. However, comparatively little information exists on the dynamics of water use by indigenous plants in the region, and, in particular, how water use varies seasonally and between sites. In this study we determined water use by 3 fynbos vegetation types growing at 4 different sites, namely: (i) lowland Atlantis Sand Plain fynbos growing on deep sandy soils, (ii) Kogelberg Sandstone fynbos growing in a riparian zone on deep alluvial soils, (iii) dryland Kogelberg Sandstone fynbos growing on shallow sandy soils at a montane site, and (iv) alluvial Swartland fynbos growing in clayey soils. Evapotranspiration (ET) was quantified at each site during specific periods using a boundary layer scintillometer and energy balance system. A simple dual source model in which the stand ET was calculated as the algebraic sum of outputs from soil evaporation and transpiration sub-models was used to scale up the ET measurements to annual values. The data showed large differences in ET depending on site characteristics and on plant attributes. Dense stands of riparian Sandstone Fynbos had an annual ET of 1 460 mm which exceeded the reference ET of 1 346 mm. Dryland Sandstone Fynbos used only 551 mm of water per year while the Sand Plain Fynbos' annual ET was 1 031 mm, which was similar to the reference ET of 1 059 mm. We conclude that some indigenous plant species use large volumes of water which should be accounted for in, e.g., groundwater recharge estimates, and calculations of incremental water gains after clearing alien invasive plants, among other applications
13. Configuration of water resources for a typical river basin in an arid region of China based on the ecological water requirements (EWRs) of desert riparian vegetation
Science.gov (United States)
Ling, Hongbo; Guo, Bin; Xu, Hailiang; Fu, Jinyi
2014-11-01
Desert riparian vegetation is a natural cover promoting the stability and development of inland river ecosystems in arid regions. Calculating the ecological water requirements (EWRs) of desert riparian vegetation is an important step in achieving reasonable water utilization. Therefore, this study examined the Tarim River, located in an extremely arid region of China, and collected relevant data on hydrology, weather and vegetation using remote sensing. Subsequently, we analyzed the spatial distribution of the desert riparian vegetation in four sections of the Tarim River and calculated the EWR of the desert riparian vegetation using the phreatic evaporation model; additionally, we determined the required runoffs at five hydrologic stations based on the water balance principle. Ultimately, the necessary protection ranges and goals for desert riparian vegetation were established according to the water resource variations in the Tarim River. Our research showed that the total area of desert riparian vegetation along the Tarim River is 16,285.3 km2; this distribution area gradually decreased as the distance from the river increased, and areas varied in the different river sections. The EWRs of desert riparian vegetation from Sections 1 to 5 are 5.698 × 108, 7.585 × 108, 4.900 × 108, 4.101 × 108 m3 and 1.078 × 108 m3, respectively. Therefore, the total EWR of the study region is 23.362 × 108 m3. In terms of the transpiration law of the "unimodal type", the peak value of EWR of natural vegetation occurs in July, and the decreasing trend appears in the other months. Based on the water balance principle, the required runoffs in Alar, Xinquman, Yingbaza, Wusiman and Qiala were determined to be 47.105 × 108, 35.174 × 108, 22.734 × 108, 15.775 × 108 and 7.707 × 108 m3, respectively. According to the water resource frequency and the EWR of the desert riparian vegetation along the Tarim River, we divided the region into three protection ranges: key protection (8.9-11.8 km from the river), basic protection (15.8-21.8 km from the river) and influence protection (43.0 km from the river). This research not only provides a reasonable calculation method for EWR on the scale of a river basin but also supports the healthy development of the desert riparian vegetation ecosystem and helps to achieve the optimal water allocation for this river.
14. A review of fire effects on vegetation and soils in the Great Basin region: response and ecological site characteristics
Science.gov (United States)
Miller, Richard F.; Chambers, Jeanne C.; Pyke, David A.; Pierson, Fred B.; Williams, C. Jason
2013-01-01
This review synthesizes the state of knowledge on fire effects on vegetation and soils in semi-arid ecosystems in the Great Basin Region, including the central and northern Great Basin and Range, Columbia River Basin, and the Snake River Plain. We summarize available literature related to: (1) the effects of environmental gradients, ecological site, and vegetation characteristics on resilience to disturbance and resistance to invasive species; (2) the effects of fire on individual plant species and communities, biological soil crusts, seed banks, soil nutrients, and hydrology; and (3) the role of fire severity, fire versus fire surrogate treatments, and post-fire grazing in determining ecosystem response. From this, we identify knowledge gaps and present a framework for predicting plant successional trajectories following wild and prescribed fires and fire surrogate treatments. Possibly the three most important ecological site characteristics that influence a site’s resilience (ability of the ecological site to recover from disturbance) and resistance to invasive species are soil temperature/moisture regimes and the composition and structure of vegetation on the ecological site just prior to the disturbance event.
15. Vegetation Dynamics Depending on Ecological Particularities of Bozanta Mare (Maramures County-Romania Tailing Pound. Case Study
Directory of Open Access Journals (Sweden)
Monica Marian
2009-01-01
Full Text Available The present study follows an ecological demarch of reintegration in the scenary through revegetation of an anthropic ground, consisting in a waste pond formed from the flotation activity of non-ferrous ores. Problem statement: To support the formation of a compact vegetal layer, having an anti-errosion and a restoration role, a preliminary study was required regarding the spontaneous settlement of different vegetal species. We have followed the specific floristic composition and the biodiversity on the waste pond, the manner of association of plant species, and the possible interractions with other species from the biocenosis (microorganisms and fungi. We have also studied the pace at which vegetal species settle, as well as the reciprocal influence, from the point of view of vegetation, with the neighbouring area, since the desideratum is the settlement of a vegetation similar to the natural one. Approach: The aim of the research is to draw a list of the vegetal taxa installed on the pond, as well as to detect some succession stages or some possible vegetal associations. We have established the share of different species in the vegetal layer on the waste pond through an analysis of the ecological preferences, of the geographical origin of plant species, of the cariological and bioform profile. All this was done to compare the possible vegetal associations which settle on such anthropic grounds with the neighbouring vegetation. The approach used was the classical one in fitosociology, recommended by the Central European Fitosociological School adapted to the pedo-climatic conditions in Romania. Results: Over 50 species of plants and fungi spontaniously settled have been listed, and we have followed their association as well as their distribution, compared to the microclimatical conditions of the waste pond. In this way,we have distinguished species with a large potential of revegetating highly polluted with heavy metals waste ponds and sites. Conclusions/Recommendations: Starting from this study, we may establish a formula of sustaining the vegetation and using the interractions among species in order to stimulate the settlement of a dense vegetation which might ensure anti-errosion protection and landscape integration.
16. Using Dehydrated Vegetables in Some Brown Bread Types
OpenAIRE
2013-01-01
Expanding the range of bakery products in terms of producing supplemented or dietetic products has been an increasingly important trend in contemporary baking. Bakery products as basic and popular food, could be used in the prevention of nutritive deficiencies of many important nutrients, by supplementing the products with biologically valuable ingredients. Such ingredients are dehydrated vegetables in the form of powder. For establishing the bread quality, a special importance shows it’s ch...
17. Vegetation change and emerging research feedback for Korean National Long Term Ecological Research (KNLTER
Directory of Open Access Journals (Sweden)
Yong Chan Cho
2011-03-01
Full Text Available Various responses of forest ecosystems to climate change underscore the need to improve our understanding of theenvironmentally-driven changes in forests, most effectively by long-term monitoring protocols. We have explored vegetationdynamics based on changes in community structure, species composition, diversity and demographics in fourKorean National Long Term Ecological Research (KNLTER sites--Mt. Nam, Mt. Jeombong, Mt. Worak, and Mt. Jiri--between 2004 and 2009. Most of the sites and forests studied exhibited increments in total basal area, but this was notobserved in Quercus mongolica forests in Mt. Nam and Mt. Worak. Stem density exhibited various changes. Altitudegradient was the representative factor in differences in species composition. Two patterns of compositional change--convergence and divergence--were detected. The vegetation of Mt. Nam and Q. mongolica community of Mt. Workshowed relatively larger changes in composition. However, in the other sites, few changes were observed. Changes ofspecies richness were not notable except for Mt. Nam, where three species were added in the pine forest, whereas onespecies disappeared in the oak forest. In the oak forests, mortality rate was as follows (in descending order: Mt. Nam(25.5%, Mt. Jeombong (24.3%, Mt. Worak (16.4% and Mt. Jiri (0.8%. In the pine forest, the recruitment rate was as follows(in descending order: Mt. Nam (63.7%, Mt. Worak (12.9%, Mt. Jeombong (7.6% and Mt. Jiri (7.3%. The mortalityrate and change rate of basal area were strongly negatively correlated (r = -0.9, P = 0.002, and the recruitment rate andchange rate of density were positively correlated (r = 0.77, P = 0.026. In the KNLTER sites, larger vegetation changes wereattributed to anthropogenic activities such as salvage logging. Suppression or competition for resources would also affectthese changes. Research suggestions such as monitoring to clarify the causes of species mortality were discussed.
18. Investigation of Soil Properties effects on Establishment of Vegetation Types (Case Study: Sabzdasht, Bafgh)
Science.gov (United States)
Sadeghi Nia, Majid; jafari, Mohammad; Zahedi Amiri, Ghavomoldin; Baghestani Maybodi, Naser; Tavili, Ali
2013-04-01
This research was conducted to investigate the relationships between soil (Organic Matter, potassium, phosphorous, sodium, Fine gravel, soil texture, EC, Lime, Gypsum, Nitrogen) and environmental (Elevation, Slope) factors with distribution of vegetation types in rangelands of Sabzdasht, located in Bafgh, Yazd province at 2012. For this purpose, four vegetation types were selected as follows: Artemisia sieberi; Artemisia sieberi, Stipa barbata, Eurotia ceratoides; Dorema ammoniacum, Artemisia sieberi, Eurotia ceratoides; and Hammada salicornica.Minimal area was determined using nested plots. Afterward, vegetation factors were measured and five soil profiles were dug randomly in minimal area. In each profile, data for depths of 0-10 and 10-80 cm were recorded. Principal Component Analysis was applied to analyze the data. Results showed that soil texture, potassium, phosphorous, EC and lime had the most impact on variation and distribution of vegetation types. Keywords: Environmental Factors, Principal Component Analysis, Minimal Area, Bafgh, Yazd
19. VEGETATION MAPPING IN WETLANDS
Directory of Open Access Journals (Sweden)
F. PEDROTTI
2004-01-01
Full Text Available The current work examines the main aspects of wetland vegetation mapping, which can be summarized as analysis of the ecological-vegetational (ecotone gradients; vegetation complexes; relationships between vegetation distribution and geomorphology; vegetation of the hydrographic basin lo which the wetland in question belongs; vegetation monitoring with help of four vegetation maps: phytosociological map of the real and potential vegetation, map of vegetation dynamical tendencies, map of vegetation series.
20. VEGETATION MAPPING IN WETLANDS
OpenAIRE
F. PEDROTTI
2004-01-01
The current work examines the main aspects of wetland vegetation mapping, which can be summarized as analysis of the ecological-vegetational (ecotone) gradients; vegetation complexes; relationships between vegetation distribution and geomorphology; vegetation of the hydrographic basin lo which the wetland in question belongs; vegetation monitoring with help of four vegetation maps: phytosociological map of the real and potential vegetation, map of vegetation dynamical tendencies, map of veget...
1. Productive vegetation: relationships between net primary productivity, vegetation types and climate change in the Wet Tropics bioregion
International Nuclear Information System (INIS)
Full text: Full text: There is now ample evidence demonstrating the impacts of climate change on biodiversity and human society (Walther ef a/. 2002). Numerous studies have shown climate change is one of the most significant threats to tropical forests, such as the Wet Tropics Heritage Area, due to their high biodiversity and endemism (Pounds ef al. 1999; Hughes 2000; Parmesan and Yohe 2003). Williams ef al. (2003) suggested that small shifts in net primary productivity (NPP) as a result of climate change could lead to potentially massive follow-on effects for the extremely diverse and vulnerable rainforest flora and fauna. It is therefore crucial to explore the relationships between NPP and local biodiversity, especially to create models for different climate change scenarios. Nevertheless, NPP in the Wet Tropics has yet to be estimated. This is the first study to provide a general NPP estimate for the Wet Tropics bioregion using climate surrogates (Schuur 2003). This technique estimates NPP in an accurate, repeatable, and cost-effective way. NPP values were linked to vegetation types and examined under various climatic and environmental conditions. Results show a significant difference in productivity according to vegetation types and climatic variables, with temperature and rainfall seasonality as the most important determining variables. Additionally, lowland and upland vegetations showed a significant difference in productivity patterns throughout the year. Vegetation types located above 1000 metres in altitude had the lowest values of mean annual productivity due to their high rainfall and low temperatures; vegetation types located below 600 metres showed increased productivity values during the wet season (December-March). Net primary productivity will certainly be impacted by changes in temperature and rainfall, due to climate change. Although an increase in NPP values can be predicted for upland areas, the more widely distributed lowlands will drastically decrease their productivity values. Information regarding the variability of net primary productivity across the Wet Tropics bioregion and its possible modifications due to climate change is crucial for management of future scenarios. The results from this study will help management agencies and conservation groups to plan accordingly
2. Using Dehydrated Vegetables in Some Brown Bread Types
Directory of Open Access Journals (Sweden)
Simona Man
2013-11-01
Full Text Available Normal 0 false false false MicrosoftInternetExplorer4 Expanding the range of bakery products in terms of producing supplemented or dietetic products has been an increasingly important trend in contemporary baking. Bakery products as basic and popular food, could be used in the prevention of nutritive deficiencies of many important nutrients, by supplementing the products with biologically valuable ingredients. Such ingredients are dehydrated vegetables in the form of powder. For establishing the bread quality, a special importance shows it’s chemical composition, because the substances that enter in it’s constitution serve to obtaining the energy necessary to the human body. Beside the chemical composition, the bread quality and alimentary use, respectively, depends a large measure on a series of signs: flavor and taste, external appearance, crumb porosity and texture, breads’ volume. This paper belongs to a more complex study, which aims are obtaining some bread assortments with high nutritional value, and improving their sensorial and rheological features, by adding dehydrated vegetables at different levels 4% potato flakes, 2% dehydrated onion, 0.5% dehydrated garlic and 2% dehydrated leek.
3. LBA-ECO LC-22 Vegetation Cover Types from MODIS, 500-m, South America: 2000-2001
National Aeronautics and Space Administration — This data set contains proportional estimates for the vegetative cover types of tree cover, herbaceous vegetation, and bare ground over South America for the period...
4. LBA-ECO LC-22 Vegetation Cover Types from MODIS, 500-m, South America: 2000-2001
National Aeronautics and Space Administration — ABSTRACT: This data set contains proportional estimates for the vegetative cover types of tree cover, herbaceous vegetation, and bare ground over South America for...
5. Nitrogen deposition effects on Mediterranean-type ecosystems: an ecological assessment.
Science.gov (United States)
Ochoa-Hueso, Raúl; Allen, Edith B; Branquinho, Cristina; Cruz, Cristina; Dias, Teresa; Fenn, Mark E; Manrique, Esteban; Pérez-Corona, M Esther; Sheppard, Lucy J; Stock, William D
2011-10-01
We review the ecological consequences of N deposition on the five Mediterranean regions of the world. Seasonality of precipitation and fires regulate the N cycle in these water-limited ecosystems, where dry N deposition dominates. Nitrogen accumulation in soils and on plant surfaces results in peaks of availability with the first winter rains. Decoupling between N flushes and plant demand promotes losses via leaching and gas emissions. Differences in P availability may control the response to N inputs and susceptibility to exotic plant invasion. Invasive grasses accumulate as fuel during the dry season, altering fire regimes. California and the Mediterranean Basin are the most threatened by N deposition; however, there is limited evidence for N deposition impacts outside of California. Consequently, more research is needed to determine critical loads for each region and vegetation type based on the most sensitive elements, such as changes in lichen species composition and N cycling. PMID:21277663
6. Nitrogen deposition effects on Mediterranean-type ecosystems: An ecological assessment
Energy Technology Data Exchange (ETDEWEB)
Ochoa-Hueso, Raul, E-mail: [email protected] [Department of Plant Physiology and Ecology, Centro de Ciencias Medioambientales, Consejo Superior de Investigaciones Cientificas, C/Serrano 115 Dpdo., 28006 Madrid (Spain); Allen, Edith B. [Department of Botany and Plant Sciences and Center for Conservation Biology, University of California, Riverside, CA 92521 (United States); Branquinho, Cristina; Cruz, Cristina; Dias, Teresa [Universidade de Lisboa, Faculdade de Ciencias, Centro de Biologia Ambiental, Campo Grande, Bloco C4, 1749-016 Lisboa (Portugal); Fenn, Mark E. [US Department of Agriculture (USDA) Forest Service, Pacific Southwest Research Station, 4955 Canyon Crest Drive, Riverside, CA 92507 (United States); Manrique, Esteban [Department of Plant Physiology and Ecology, Centro de Ciencias Medioambientales, Consejo Superior de Investigaciones Cientificas, C/Serrano 115 Dpdo., 28006 Madrid (Spain); Perez-Corona, M. Esther [Department of Ecology, Faculty of Biology, Universidad Complutense de Madrid, C/Jose Antonio Novais 2, 28040 Madrid (Spain); Sheppard, Lucy J. [Centre of Ecology and Hydrology, Bush Estate, Penicuik EH26 0QB (United Kingdom); Stock, William D. [Centre for Ecosystem Management, School of Natural Sciences, Edith Cowan University, 100 Joondalup Drive, Joondalup, Perth, WA 6027 (Australia)
2011-10-15
We review the ecological consequences of N deposition on the five Mediterranean regions of the world. Seasonality of precipitation and fires regulate the N cycle in these water-limited ecosystems, where dry N deposition dominates. Nitrogen accumulation in soils and on plant surfaces results in peaks of availability with the first winter rains. Decoupling between N flushes and plant demand promotes losses via leaching and gas emissions. Differences in P availability may control the response to N inputs and susceptibility to exotic plant invasion. Invasive grasses accumulate as fuel during the dry season, altering fire regimes. California and the Mediterranean Basin are the most threatened by N deposition; however, there is limited evidence for N deposition impacts outside of California. Consequently, more research is needed to determine critical loads for each region and vegetation type based on the most sensitive elements, such as changes in lichen species composition and N cycling. - Highlights: > N deposition impacts are understudied in Mediterranean ecosystems out of California. > Dry N deposition is dominant and N flushes are common after rainless periods. > Water availability and P fertility regulate ecosystem responses to N deposition. > Research is needed to determine critical loads for each region and vegetation type. - Nitrogen deposition threatens the Mediterranean regions of the world.
7. Nitrogen deposition effects on Mediterranean-type ecosystems: An ecological assessment
International Nuclear Information System (INIS)
We review the ecological consequences of N deposition on the five Mediterranean regions of the world. Seasonality of precipitation and fires regulate the N cycle in these water-limited ecosystems, where dry N deposition dominates. Nitrogen accumulation in soils and on plant surfaces results in peaks of availability with the first winter rains. Decoupling between N flushes and plant demand promotes losses via leaching and gas emissions. Differences in P availability may control the response to N inputs and susceptibility to exotic plant invasion. Invasive grasses accumulate as fuel during the dry season, altering fire regimes. California and the Mediterranean Basin are the most threatened by N deposition; however, there is limited evidence for N deposition impacts outside of California. Consequently, more research is needed to determine critical loads for each region and vegetation type based on the most sensitive elements, such as changes in lichen species composition and N cycling. - Highlights: ? N deposition impacts are understudied in Mediterranean ecosystems out of California. ? Dry N deposition is dominant and N flushes are common after rainless periods. ? Water availability and P fertility regulate ecosystem responses to N deposition. ? Research is needed to determine critical loads for each region and vegetation type. - Nitrogen deposition threatens the Mediterranean regions of the world.
8. Arctic Tundra Vegetation Functional Types Based on Photosynthetic Physiology and Optical Properties
Science.gov (United States)
Huemmrich, Karl Fred; Gamon, John A.; Tweedie, Craig E.; Campbell, Petya K. Entcheva; Landis, David R.; Middleton, Elizabeth M.
2013-01-01
Non-vascular plants (lichens and mosses) are significant components of tundra landscapes and may respond to climate change differently from vascular plants affecting ecosystem carbon balance. Remote sensing provides critical tools for monitoring plant cover types, as optical signals provide a way to scale from plot measurements to regional estimates of biophysical properties, for which spatial-temporal patterns may be analyzed. Gas exchange measurements were collected for pure patches of key vegetation functional types (lichens, mosses, and vascular plants) in sedge tundra at Barrow, AK. These functional types were found to have three significantly different values of light use efficiency (LUE) with values of 0.013 plus or minus 0.0002, 0.0018 plus or minus 0.0002, and 0.0012 plus or minus 0.0001 mol C mol (exp -1) absorbed quanta for vascular plants, mosses and lichens, respectively. Discriminant analysis of the spectra reflectance of these patches identified five spectral bands that separated each of these vegetation functional types as well as nongreen material (bare soil, standing water, and dead leaves). These results were tested along a 100 m transect where midsummer spectral reflectance and vegetation coverage were measured at one meter intervals. Along the transect, area-averaged canopy LUE estimated from coverage fractions of the three functional types varied widely, even over short distances. The patch-level statistical discriminant functions applied to in situ hyperspectral reflectance data collected along the transect successfully unmixed cover fractions of the vegetation functional types. The unmixing functions, developed from the transect data, were applied to 30 m spatial resolution Earth Observing-1 Hyperion imaging spectrometer data to examine variability in distribution of the vegetation functional types for an area near Barrow, AK. Spatial variability of LUE was derived from the observed functional type distributions. Across this landscape, a fivefold variation in tundra LUE was observed. LUE calculated from the functional type cover fractions was also correlated to a spectral vegetation index developed to detect vegetation chlorophyll content. The concurrence of these alternate methods suggest that hyperspectral remote sensing can distinguish functionally distinct vegetation types and can be used to develop regional estimates of photosynthetic LUE in tundra landscapes.
9. Ecología de la vegetación del desierto chihuahuense / Vegetation ecology of the chihuahuan desert
Scientific Electronic Library Online (English)
Diódoro, Granados-Sánchez; Arturo, Sánchez-González; Ro Linnx, Granados Victorino; Amparo, Borja de la Rosa.
Full Text Available El desierto Chihuahuense (DC), el más grande del Continente Americano, está flanqueado por montañas que impiden el paso de los vientos húmedos: la Sierra Madre Oriental, la Faja Volcánica Trans-mexicana y la Sierra Madre Occidental (en México) y Las Rocallosas (en Estados Unidos); cubre una superfic [...] ie de 507,000 km², desde Nuevo México y Texas en Estados Unidos, hasta porciones de los estados de Chihuahua, Coahuila, Durango, Guanajuato, Hidalgo, Nuevo León, Querétaro, San Luis Potosí, Tamaulipas y Zacatecas, en México. El trabajo en campo consistió en la caracterización cualitativa de los principales tipos de vegetación del DC, con base en su fisonomía y en la recolección de ejemplares vegetales para su posterior identificación. Con los datos de composición y fisonomía se elaboraron perfiles semirrealistas de las principales asociaciones vegetales y de las condiciones fisiográficas y edáficas donde se desarrollaban. Las asociaciones detectadas fueron: matorral micrófilo de Larrea tridentata, matorral rosetófilo de Agave lechuguilla, matorral rosetófilo de Dasylirion spp., pastizal, chaparral, nopalera, mezquital, izotal, vegetación de dunas y vegetación halófita. Abstract in english The Chihuahuan Desert (CD), the largest in the Americas, is flanked by mountains that prevent wet winds from blowing across it; those mountain ranges are the Sierra Madre Oriental, the Trans-Mexican Volcanic Belt and the Sierra Madre Occidental in Mexico, and the Rockies in the United States. The de [...] sert covers an area of 507,000 km2, stretching from New Mexico and Texas in the United States to parts of the states of Chihuahua, Coahuila, Durango, Guanajuato, Hidalgo, Nuevo León, Querétaro, San Luis Potosi, Tamaulipas and Zacatecas in Mexico. Field work consisted of the qualitative characterization of the main vegetation types in the CH, based on their physiognomy and the collection of plant specimens for later identification. With the composition and physiognomy data, semi-realistic profiles were made of the main plant associations and the physiographic and soil conditions where they thrive. The associations detected were: Larrea tridentata microphyll scrub, Agave lechuguilla rosette scrub, Dasylirion spp. rosette scrub, grassland, chaparral, nopalera (a patch of prickly pears), mesquite, yucca, dune vegetation and halophytic vegetation.
10. Ecology
International Nuclear Information System (INIS)
The book turns to the freshment, the teacher, for preparation of ecological topics for lessons, but also to pupils of the secondary stage II, and the main course ecology. The book was knowingly held simple with the restriction to: the ecosystem and its abiotic basic functions, simple articles on population biology, bioceonotic balance ith the questions of niche formation and the life form types coherent with it, of the substance and energy household, the production biology and space-wise and time-wise differentations within an ecological system form the main points. A central role in the volume is given to the illustrations. Their variety is to show and deepen the coherences shown. (orig./HP)
11. Vegetation and Vertebrates of the Patuxent Wildlife Research Center, Outline of Ecology and Annotated Lists 1947
US Fish and Wildlife Service, Department of the Interior — This is an extensive list of vegetation and vertebrates at the Patuxent Wildlife Research Center based on information gathered during the years 19361946.
12. Vegetation Classification, Inventory, and Ecological Integrity Assessment of the Wet Meadow Habitats: Malheur National Wildlife Refuge
US Fish and Wildlife Service, Department of the Interior — This project was funded through the Region 1 Inventory and Monitoring Initiative RFP in 2011. The primary objectives of this project were to develop a vegetation...
13. Effects of neighboring vascular plants on the abundance of bryophytes in different vegetation types
Science.gov (United States)
Jägerbrand, Annika K.; Kudo, Gaku; Alatalo, Juha M.; Molau, Ulf
2012-07-01
Due to the climate change, vegetation of tundra ecosystems is predicted to shift toward shrub and tree dominance, and this change may influence bryophytes. To estimate how changes in growing environment and the dominance of vascular plants influence bryophyte abundance, we compared the relationship of occurrence of bryophytes among other plant types in a five-year experiment of warming (T), fertilization (F) and T + F in two vegetation types, heath and meadow, in a subarctic-alpine ecosystem. We compared individual leaf area among shrub species to confirm that deciduous shrubs might cause severe shading effect. Effects of neighboring functional types on the performance of Hylocomium splendens was also analyzed. Results show that F and T + F treatments significantly influenced bryophyte abundance negatively. Under natural conditions, bryophytes in the heath site were negatively related to the abundance of shrubs and lichens and the relationship between lichens and bryophytes strengthened after the experimental period. After five years of experimental treatments in the meadow, a positive abundance relationship emerged between bryophytes and deciduous shrubs, evergreen shrubs and forbs. This relationship was not found in the heath site. Our study therefore shows that the abundance relationships between bryophytes and plants in two vegetation types within the same area can be different. Deciduous shrubs had larger leaf area than evergreen shrubs but did not show any shading effect on H. splendens.
14. Relationships between NDVI, canopy structure, and photosynthesis in three California vegetation types
International Nuclear Information System (INIS)
In a range of plant species from three Californian vegetation types, we examined the widely used ''normalized difference vegetation index'' (NDVI) and ''simple ratio'' (SR) as indicators of canopy structure, light absorption, and photosynthetic activity. These indices, which are derived from canopy reflectance in the red and near-infrared wavebands, highlighted phenological differences between evergreen and deciduous canopies. They were poor indicators of total canopy biomass due to the varying abundance of non-green standing biomass in these vegetation types. However, in sparse canopies (leaf area index (LAI) apprxeq 0-2), NDVI was a sensitive indicator of canopy structure and chemical content (green biomass, green leaf area index, chlorophyll content, and foliar nitrogen content). At higher canopy green LAI values ( gt 2; typical of dense shrubs and trees), NDVI was relatively insensitive to changes in canopy structure. Compared to SR, NDVI was better correlated with indicators of canopy structure and chemical content, but was equivalent to the logarithm of SR. In agreement with theoretical expectations, both NDVI and SR exhibited near-linear correlations with fractional PAR intercepted by green leaves over a wide range of canopy densities. Maximum daily photosynthetic rates were positively correlated with NDVI and SR in annual grassland and semideciduous shrubs where canopy development and photosynthetic activity were in synchrony. The indices were also correlated with peak springtime canopy photosynthetic rates in evergreens. However, over most of the year, these indices were poor predictors of photosynthetic performance in evergreen species due to seasonal reductions in photosynthetic radiation-use efficiency that occurred without substantial declines in canopy greenness. Our results support the use of these vegetation indices as remote indicators of PAR absorption, and thus potential photosynthetic activity, even in heterogeneous landscapes. To provide accurate estimates of vegetation atmosphere gas fluxes, remote NDVI and SR measurements need to be coupled with careful estimates of canopy photosynthetic radiation-use efficiency. (author)
15. A Broad Approach to Abrupt Boundaries: Looking Beyond the Boundary at Soil Attributes within and Across Tropical Vegetation Types
OpenAIRE
Warman, Laura; Bradford, Matt G.; Moles, Angela T.
2013-01-01
Most research on boundaries between vegetation types emphasizes the contrasts and similarities between conditions on either side of a boundary, but does not compare boundary to non-boundary vegetation. That is, most previous studies lack suitable controls, and may therefore overlook underlying aspects of landscape variability at a regional scale and underestimate the effects that the vegetation itself has on the soil. We compared 25 soil chemistry variables in rainforest, sclerophyll vegetati...
16. Effect of non-crop vegetation types on conservation biological control of pests in olive groves
Directory of Open Access Journals (Sweden)
Daniel Paredes
2013-07-01
Full Text Available Conservation biological control (CBC is an environmentally sound potential alternative to the use of chemical insecticides. It involves modifications of the environment to promote natural enemy activity on pests. Despite many CBC studies increasing abundance of natural enemies, there are far fewer demonstrations of reduced pest density and very little work has been conducted in olive crops. In this study we investigated the effects of four forms of non-crop vegetation on the abundance of two important pests: the olive psyllid (Euphyllura olivina and the olive moth (Prays oleae. Areas of herbaceous vegetation and areas of woody vegetation near olive crops, and smaller patches of woody vegetation within olive groves, decreased pest abundance in the crop. Inter-row ground covers that are known to increase the abundance of some predators and parasitoids had no effect on the pests, possibly as a result of lack of synchrony between pests and natural enemies, lack of specificity or intra-guild predation. This study identifies examples of the right types of diversity for use in conservation biological control in olive production systems.
17. Temporal variations in soil moisture for three typical vegetation types in inner Mongolia, northern China.
Science.gov (United States)
Zheng, Hao; Gao, Jixi; Teng, Yanguo; Feng, Chaoyang; Tian, Meirong
2015-01-01
Drought and shortages of soil water are becoming extremely severe due to global climate change. A better understanding of the relationship between vegetation type and soil-moisture conditions is crucial for conserving soil water in forests and for maintaining a favorable hydrological balance in semiarid areas, such as the Saihanwula National Nature Reserve in Inner Mongolia, China. We investigated the temporal dynamics of soil moisture in this reserve to a depth of 40 cm under three types of vegetation during a period of rainwater recharge. Rainwater from most rainfalls recharged the soil water poorly below 40 cm, and the rainfall threshold for increasing the moisture content of surface soil for the three vegetations was in the order: artificial Larix spp. (AL) > Quercus mongolica (QM) > unused grassland (UG). QM had the highest mean soil moisture content (21.13%) during the monitoring period, followed by UG (16.52%) and AL (14.55%); and the lowest coefficient of variation (CV 9.6-12.5%), followed by UG (CV 10.9-18.7%) and AL (CV 13.9-21.0%). QM soil had a higher nutrient content and higher soil porosities, which were likely responsible for the higher ability of this cover to retain soil water. The relatively smaller QM trees were able to maintain soil moisture better in the study area. PMID:25781333
18. Diversity in a complex ecological network with two interaction types.
Czech Academy of Sciences Publication Activity Database
Melián, C. J.; Bascompte, J.; Jordano, P.; K?ivan, Vlastimil
2009-01-01
Ro?. 118, ?. 1 (2009), s. 122-130. ISSN 0030-1299 R&D Projects: GA AV ?R IAA100070601 Grant ostatní: University of California(US) DEB-0553768; The Spanish Ministry of Science and Technology(ES) REN2003-04774; The Spanish Ministry of Science and Technology(ES) REN2003-00273 Institutional research plan: CEZ:AV0Z50070508 Keywords : complex ecological network Subject RIV: EH - Ecology, Behaviour Impact factor: 3.147, year: 2009
19. Satellite monitoring of different vegetation types by differential optical absorption spectroscopy (DOAS in the red spectral range
Directory of Open Access Journals (Sweden)
T. Wagner
2007-01-01
Full Text Available A new method for the satellite remote sensing of different types of vegetation and ocean colour is presented. In contrast to existing algorithms relying on the strong change of the reflectivity in the red and near infrared spectral region, our method analyses weak narrow-band (few nm reflectance structures (i.e. "fingerprint" structures of vegetation in the red spectral range. It is based on differential optical absorption spectroscopy (DOAS, which is usually applied for the analysis of atmospheric trace gas absorptions. Since the spectra of atmospheric absorption and vegetation reflectance are simultaneously included in the analysis, the effects of atmospheric absorptions are automatically corrected (in contrast to other algorithms. The inclusion of the vegetation spectra also significantly improves the results of the trace gas retrieval. The global maps of the results illustrate the seasonal cycles of different vegetation types. In addition to the vegetation distribution on land, they also show patterns of biological activity in the oceans. Our results indicate that improved sets of vegetation spectra might lead to more accurate and more specific identification of vegetation type in the future.
20. Tropical alpine treelines : how ecological processes control vegetation patterning and dynamics
OpenAIRE
2007-01-01
The alpine treeline, defined as the transition between upper montane forest and alpine vegetation, can be a gradual transition, an abrupt boundary, or a patchy mosaic. The position of the treeline in the landscape also varies between regions. These different spatial patterns are caused by processes that also determine the dynamic properties of the treeline, such as its response to changes in climate or landuse. Spatial patterns may therefore serve to indicate the temporal dynamics that a tree...
1. An Ecological Study of Roadside Vegetation and Soils in Sahiwal District
OpenAIRE
2003-01-01
The present study was carried out to investigate the floristic composition of roadside vegetation and levels of some heavy metals in roadside soils in Sahiwal district, Pakistan. Among sixty recorded species, the main grass species include Cynodon dactylon, Desmostachya bipinnata, Panicum turgidum, Cyperus rotundus and Cenchrus biflorus. The dominant species exhibited little variation between different zones of verges. Other species however, showed preferences for certain zones of the v...
2. The influence of distinct types of aquatic vegetation on the flow field
Science.gov (United States)
Valyrakis, Manousos; Barcroft, Stephen; Yagci, Oral
2014-05-01
The Sustainable management of fluvial systems dealing with flood prevention, erosion protection and restoration of rivers and estuaries requires implementation of soft/green-engineering methods. In-stream aquatic vegetation can be regarded as one of these as it plays an important role for both river ecology (function) and geomorphology (form). The goal of this research is to offer insight gained from pilot experimental studies on the effects of a number of different elements modeling instream, aquatic vegetation on the local flow field. It is hypothesized that elements of the same effective "blockage" area but of distinct characteristics (structure, porosity and flexibility), will affect both the mean and fluctuating levels of the turbulent flow to a different degree. The above hypothesis is investigated through a set of rigorous set of experimental runs which are appropriately designed to assess the variability between the interaction of aquatic elements and flow, both quantitatively and qualitatively. In this investigation three elements are employed to model aquatic vegetation, namely a rigid cylinder, a porous but rigid structure and a flexible live plant (Cupressus Macrocarpa). Firstly, the flow field downstream each of the mentioned elements was measured under steady uniform flow conditions employing acoustic Doppler velocimetry. Three-dimensional flow velocities downstream the vegetation element are acquired along a measurement grid extending about five-fold the element's diameter. These measurements are analyzed to develop mean velocity and turbulent intensity profiles for all velocity components. A detailed comparison between the obtained results is demonstrative of the validity of the above hypothesis as each of the employed elements affects in a different manner and degree the flow field. Then a flow visualization technique, during which fluorescent dye is injected upstream of the element and images are captured for further analysis and comparison, was employed to visualize the flow structures shed downstream the aquatic elements. This method allows to further observe qualitatively and visually identify the different characteristics of the eddies advected downstream, conclusively confirming the results of the aforementioned experimental campaign.
3. Accuracy assessment of airphoto interpretation of vegetation types and disturance levels on winter seismic trails, Arctic National Wildlife Refuge, Alaska
US Fish and Wildlife Service, Department of the Interior — An accuracy assessment was conducted to evaluate the photointerpretation of vegetation types and disturbance levels along seismic trails in the Arctic National...
4. Effects of storage time and temperature on the characteristics of vegetable-type soybean grain minimally processed
OpenAIRE
Karina Czaikoski; Mercedes Concórdia Carrão-Panizzi; Josemeyre Bonifácio da Silva; Elza Iouko Ida
2012-01-01
The objective of this study was to evaluate the effects of storage time and temperature on the characteristics of vegetable-type soybean grain (cultivar BRS 267) minimally processed and to define the best conditions for its storage. The evaluation was performed by measurement of vitamin C levels, weight loss and color parameters (L*, a*, and b*). The time of storage of vegetable-type soybean grains minimally processed and storage in Styrofoam trays and wrapped with PVC film, caused a decrease...
5. Relation of MODIS EVI and LAI across time, vegetation types and hydrological regimes
Science.gov (United States)
Alexandridis, Thomas; Ovakoglou, George
2015-04-01
Estimation of the Leaf Area Index (LAI) of a landscape is considered important to describe the ecosystems activity and is used as an important input parameter in hydrological and biogeochemical models related to water and carbon cycle, desertification risk, etc. The measurement of LAI in the field is a laborious and costly process and is mainly done by indirect methods, such as hemispherical photographs that are processed by specialized software. For this reason there have been several attempts to estimate LAI with multispectral satellite images, using theoretical biomass development models, or empirical equations using vegetation indices and land cover maps. The aim of this work is to study the relation of MODIS EVI and LAI across time, vegetation type, and hydrological regime. This was achieved by studying 120 maps of EVI and LAI which cover a hydrological year and five hydrologically diverse areas: river Nestos in Greece, Queimados catchment in Brazil, Rijnland catchment in The Netherlands, river Tamega in Portugal, and river Umbeluzi in Mozambique. The following Terra MODIS composite datasets were downloaded for the hydrological year 2012-2013: MOD13A2 "Vegetation Indices" and MCD15A2 "LAI and FPAR", as well as the equivalent quality information layers (QA). All the pixels that fall in a vegetation land cover (according to the MERIS GLOBCOVER map) were sampled for the analysis, with the exception of those that fell at the border between two vegetation or other land cover categories, to avoid the influence of mixed pixels. Using linear regression analysis, the relationship between EVI and LAI was identified per date, vegetation type and study area. Results show that vegetation type has the highest influence in the variation of the relationship between EVI and LAI in each study area. The coefficient of determination (R2) is high and statistically significant (ranging from 0.41 to 0.83 in 90% of the cases). When plotting the EVI factor from the regression equation across time, there is an evident temporal change in all test sites. The sensitivity of EVI to LAI is smaller in periods of high biomass production. The range of fluctuation is different across sites, and is related to biomass quantity and type. Higher fluctuation is noted in the winter season in Tamega, possibly due to cloud infected pixels that the QA and compositing algorithms did not successfully detect. Finally, there was no significant difference in the R2 and EVI factor when including in the analyses pixels indicated as "low and marginal quality" by the QA layers, thus suggesting that the use of low quality pixels can be justified when good quality pixels are not enough. Future work will study the transferability of these relations across scales and sensors. This study is supported by the Research Committee of Aristotle University of Thessaloniki project "Improvement of the estimation of Leaf Area Index (LAI) at basin scale using satellite images". MODIS data are provided by USGS.
6. Interactions between soil moisture and Atmospheric Boundary Layer at the Brazilian savana-type vegetation Cerrado
Science.gov (United States)
Pinheiro, L. R.; Siqueira, M. B.
2013-05-01
Before the large people influx and development of the central part of Brazil in the sixties, due to new capital Brasília, Cerrado, a typical Brazilian savanna-type vegetation, used to occupy about 2 million km2, going all the way from the Amazon tropical forest, in the north of the country, to the edges of what used to be of the Atlantic forest in the southeast. Today, somewhat 50% of this area has given place to agriculture, pasture and managed forests. It is forecasted that, at the current rate of this vegetation displacement, Cerrado will be gone by 2030. Understanding how Cerrado interacts with the atmosphere and how this interaction will be modified with this land-use change is a crucial step towards improving predictions of future climate-change scenarios. Cerrado is a vegetation adapted to a climate characterized by two very distinct seasons, a wet season (Nov-Mar) and dry season (May-Ago), with April and October being transitions between seasons. Typically, based on measurements in a weather station located in Brasilia, 75% of precipitation happens in the wet-season months and only 5% during dry-season. Under these circumstances, it is clear that the vegetation will have to cope with long periods of water stress. In this work we studied using numerical simulations, the interactions between soil-moisture, responsible for the water stress, with the Atmospheric Boundary Layer (ABL). The numerical model comprises of a Soil-Vegetation-Atmosphere model where the biophysical processes are represented with a big-leaf approach. Soil water is estimated with a simple logistic model and with water-stress effects on stomatal conductance are parameterized from local measurements of simultaneous latent-heat fluxes and soil moisture. ABL evolution is calculate with a slab model that considers independently surface and entrainment fluxes of sensible- and latent- heat. Temperature tropospheric lapse-rate is taken from soundings at local airport. Simulations of 30-day dry down from saturation to complete water stress were performed and is analyzed as far how ABL respond to soil moisture changes. This provides informations about ABL behavior on the transition states. Future studies will look on how this behavior will change with the new vegetation covers.
7. Major Vegetation Types of the Soutpansberg Conservancy and the Blouberg Nature Reserve, South Africa
Directory of Open Access Journals (Sweden)
Theo H.C. Mostert
2008-05-01
Full Text Available The Major Megetation Types (MVT and plant communities of the Soutpansberg Centre of Endemism are described in detail, with special reference to the Soutpansberg Conservancy and the Blouberg Nature Reserve. Phytosociological data from 442 sample plots were ordinated using a DEtrended CORrespondence ANAlysis (DECORANA and classified using TWo-Way INdicator SPecies ANalysis (TWINSPAN. The resulting classification was further refined with table-sorting procedures based on the Braun–Blanquet floristic–sociological approach of vegetation classification using MEGATAB. Eight MVT’s were identified and described as Eragrostis lehmanniana var. lehmanniana–Sclerocarya birrea subsp. caffra Blouberg Northern Plains Bushveld, Euclea divinorum–Acacia tortilis Blouberg Southern Plains Bushveld, Englerophytum magalismontanum–Combretum molle Blouberg Mountain Bushveld, Adansonia digitata–Acacia nigrescens Soutpansberg Arid Northern Bushveld, Catha edulis–Flueggia virosa Soutpansberg Moist Mountain Thickets, Diplorhynchus condylocarpon–Burkea africana Soutpansberg Leached Sandveld, Rhus rigida var. rigida–Rhus magalismontanum subsp. coddii Soutpansberg Mistbelt Vegetation and Xymalos monospora–Rhus chirendensis Soutpansberg Forest Vegetation.
8. Major vegetation types of the Soutpansberg Conservancy and the Blouberg Nature Reserve, South Africa
Scientific Electronic Library Online (English)
Theo H.C., Mostert; George J., Bredenkamp; Hannes L., Klopper; Cornie, Verwey; Rachel E., Mostert; Norbert, Hahn.
Full Text Available The Major Megetation Types (MVT) and plant communities of the Soutpansberg Centre of Endemism are described in detail, with special reference to the Soutpansberg Conservancy and the Blouberg Nature Reserve. Phytosociological data from 442 sample plots were ordinated using a DEtrended CORrespondence [...] ANAlysis (DECORANA) and classified using TWo-Way INdicator SPecies ANalysis (TWINSPAN). The resulting classification was further refined with table-sorting procedures based on the Braun-Blanquet floristic-sociological approach of vegetation classification using MEGATAB. Eight MVT's were identified and described as Eragrostis lehmanniana var. lehmanniana-Sclerocarya birrea subsp. caffra Blouberg Northern Plains Bushveld, Euclea divinorum-Acacia tortilis Blouberg Southern Plains Bushveld, Englerophytum magalismontanum-Combretum molle Blouberg Mountain Bushveld, Adansonia digitata-Acacia nigrescens Soutpansberg Arid Northern Bushveld, Catha edulis-Flueggia virosa Soutpansberg Moist Mountain Thickets, Diplorhynchus condylocarpon-Burkea africana Soutpansberg Leached Sandveld, Rhus rigida var. rigida-Rhus magalismontanum subsp. coddii Soutpansberg Mistbelt Vegetation and Xymalos monospora-Rhus chirendensis Soutpansberg Forest Vegetation.
9. Species composition and temporal activity of Arctiinae (Lepidoptera: Erebidae) in two cerrado vegetation types
OpenAIRE
Scheila Scherrer; Ferro, Viviane G.; Marina N. Ramos; Ivone R Diniz
2013-01-01
Arctiinae moths include nearly 11,000 species worldwide, of which approximately 700 species occur in the Brazilian Cerrado. The aim of this study was to describe the species composition of Arctiinae, as well as the variation in annual and nightly moth activity, in two Cerrado vegetation types. We sampled moths one night per month from September 2008 to June 2009, in the gallery forest and in the cerrado sensu stricto in the Jardim Botânico de Brasília. We collected 395 tiger moths belonging t...
10. An ecological study of the major vegetation communities of the Vaalbos National Park, Northern Cape. 1. The Than-Droogeveld section
Directory of Open Access Journals (Sweden)
H. Bezuidenhout
1994-09-01
Full Text Available A detailed classification, description and mapping of the Than-Droogeveld section of the Vaalbos National Park, Northern Cape Province, were initiated. This classification is intended to serve as an ecological basis for the establishment of an efficient wildlife management programme as well as conservation policies for the Vaalbos National Park. Using a numerical classification technique (TWINSPAN as a first approximation, the classification was refined by applying Braun-Blanquet procedures. A hierarchical classification, as well as description, ecological interpretation and a vegetation map are presented. In the phytosociological table 11 major plant communities are recognised.
11. Species composition and temporal activity of Arctiinae (Lepidoptera: Erebidae in two cerrado vegetation types
Directory of Open Access Journals (Sweden)
Scheila Scherrer
2013-04-01
Full Text Available Arctiinae moths include nearly 11,000 species worldwide, of which approximately 700 species occur in the Brazilian Cerrado. The aim of this study was to describe the species composition of Arctiinae, as well as the variation in annual and nightly moth activity, in two Cerrado vegetation types. We sampled moths one night per month from September 2008 to June 2009, in the gallery forest and in the cerrado sensu stricto in the Jardim Botânico de Brasília. We collected 395 tiger moths belonging to 65 morphospecies; 74% of the species belonged to the tribe Arctiini and 26% to Lithosiini. Thirty-one species (47.7% occurred only in the gallery forest, 13 (20% occurred only in the cerrado sensu stricto, and 21 (32.3% occurred in both vegetation types. Additionally, we found the greatest species richness between 7:00 p.m. and 8:00 p.m., and these hours were associated with 21 and 22 species, respectively. Most species (51.8% were active for up to three hours during the night. In general, the species composition differed between the dry and rainy seasons, and the similarity of the fauna also varied hourly. Based on our results, we suggest that rapid inventories of Arctiinae be performed in both rainy and dry seasons, and sampling should be carried out the entire night.
12. Species composition and temporal activity of Arctiinae (Lepidoptera: Erebidae) in two cerrado vegetation types
Scientific Electronic Library Online (English)
Scheila, Scherrer; Viviane G., Ferro; Marina N., Ramos; Ivone R., Diniz.
2013-04-01
Full Text Available Arctiinae moths include nearly 11,000 species worldwide, of which approximately 700 species occur in the Brazilian Cerrado. The aim of this study was to describe the species composition of Arctiinae, as well as the variation in annual and nightly moth activity, in two Cerrado vegetation types. We sa [...] mpled moths one night per month from September 2008 to June 2009, in the gallery forest and in the cerrado sensu stricto in the Jardim Botânico de Brasília. We collected 395 tiger moths belonging to 65 morphospecies; 74% of the species belonged to the tribe Arctiini and 26% to Lithosiini. Thirty-one species (47.7%) occurred only in the gallery forest, 13 (20%) occurred only in the cerrado sensu stricto, and 21 (32.3%) occurred in both vegetation types. Additionally, we found the greatest species richness between 7:00 p.m. and 8:00 p.m., and these hours were associated with 21 and 22 species, respectively. Most species (51.8%) were active for up to three hours during the night. In general, the species composition differed between the dry and rainy seasons, and the similarity of the fauna also varied hourly. Based on our results, we suggest that rapid inventories of Arctiinae be performed in both rainy and dry seasons, and sampling should be carried out the entire night.
13. Satellite monitoring of different vegetation types by differential optical absorption spectroscopy (DOAS) in the red spectral range
OpenAIRE
T. Wagner; Beirle, S.; T. Deutschmann; Grzegorski, M.; Platt, U (Ulrich)
2007-01-01
A new method for the satellite remote sensing of different types of vegetation and ocean colour is presented. In contrast to existing algorithms relying on the strong change of the reflectivity in the red and near infrared spectral region, our method analyses weak narrow-band (few nm) reflectance structures (i.e. "fingerprint" structures) of vegetation in the red spectral range. It is based on differential optical absorption spectroscopy (DOAS), which is usually applied for the anal...
14. Physical activity, fruit and vegetable intake and the built environment: ecological and epidemiological studies among youth
DEFF Research Database (Denmark)
Svastisalee, Chalida
2011-01-01
Since the 1990’s, there has been increasing scientific interest in investigating place effects on dietary and exercise behaviors. The two overall aims of this dissertation are designed to investigate at an area level and at an individual level, how food and physical activity resources are spatially distributed by socioeconomic indicators, and whether these associations can be observed between aspects of the built environment and: a) fruit and vegetable intake, and b) vigorous physical activity in individuals. Specifically, this involves operationalization of geographical measures of exposure within neighborhood environments, with development and validation of data used to describe characteristics of exercise and dietary resources. The concept of deprivation amplification is also investigated, which suggests that individual or household deprivation is further enhanced or comprised by the lack of resources in the neighborhood, and could manifest itself in poor health behaviors. This concept is first studied at the neighborhood level, by examining the socioeconomic patterning of food and exercise resources. Next, at the individual level, I examine the combined effects of socioeconomic status and the built environment, and report on how these associations affect individual dietary and exercise behavior. Data drawn for the individually-based analyses stem from the Danish contribution to the Health Behavior in School-aged Children Study (HBSC), an international, cross-sectional population-based study investigating the health and health behaviors of 11-to-15-year old school children. Outcome measures for these studies were infrequent less than daily intake of fruit and vegetables (Paper II) and frequent vigorous physical activity of one hour or more per day (Paper IV). The individual dataset was appended with a validated and cross-referenced objected database built for these studies and contained location information about supermarkets, fast food outlets, and various exercise-supportive resources (public open space, sports facilities, street connectivity, and total length of cycling and walking paths). The neighborhood-based analyses uses validated and cross-referenced objective data about food and physical activity resources in each of the 400 neighborhoods in Copenhagen and combines them with area-level socioeconomic and demographic data derived from The National Statistics Bank of Denmark. Outcome measures for these studies were also defined as the number of supermarkets and fast food outlets in each neighborhood (Paper I) and high exposure (top 25%) to resources supportive of physical activity. Study findings are expressed as either relative risk (RR) or odds ratios (OR), with 95% confidence intervals (CI). In general, study findings indicate no clear socioeconomic patterning of food or physical activity resources by examining neighborhood units alone. For example, there was no association between areal income and supermarket exposure in Copenhagen, while low income areas were more likely to be exposed to fewer fast food outlets than high-income neighborhoods (RR = 0.66; CI: 0.46-0.97). Areas with a high proportion of residents lacking a high school diploma had greater exposure to physical activity resources such as, public open space (OR = 1.90; CI: 1.15-3.15), cycling and walking paths (OR = 3.46; CI: 1.86-6.42) and one or more sports facilities (OR = 2.05; CI: 1.36-3.10) than the referent. Areas with high proportions of children were less likely to have exposure to connected streets (OR = 0.51; 0.31-0.83) than areas with low proportions of children. Results from individual-level studies generally show that while socioeconomic status remains an important individual predictor for diet and exercise behavior, the exposure to resources in the neighborhood environment may differentially affect children according to social class background. Children from low social class backgrounds attending schools with low exposure to supermarkets had the greatest odds of infrequent vegetable (OR = 1.50; CI: 1.03-2.20) and fruit (OR = 1.43
15. Soil and vegetation carbon stocks in Brazilian Western Amazonia: relationships and ecological implications for natural landscapes.
Science.gov (United States)
Schaefer, C E G R; do Amaral, E F; de Mendonça, B A F; Oliveira, H; Lani, J L; Costa, L M; Fernandes Filho, E I
2008-05-01
The relationships between soils attributes, soil carbon stocks and vegetation carbon stocks are poorly know in Amazonia, even at regional scale. In this paper, we used the large and reliable soil database from Western Amazonia obtained from the RADAMBRASIL project and recent estimates of vegetation biomass to investigate some environmental relationships, quantifying C stocks of intact ecosystem in Western Amazonia. The results allowed separating the western Amazonia into 6 sectors, called pedo-zones: Roraima, Rio Negro Basin, Tertiary Plateaux of the Amazon, Javari-Juruá-Purus lowland, Acre Basin and Rondonia uplands. The highest C stock for the whole soil is observed in the Acre and in the Rio Negro sectors. In the former, this is due to the high nutrient status and high clay activity, whereas in the latter, it is attributed to a downward carbon movement attributed to widespread podzolization and arenization, forming spodic horizons. The youthful nature of shallow soils of the Javari-Juruá-Purus lowlands, associated with high Al, results in a high phytomass C/soil C ratio. A similar trend was observed for the shallow soils from the Roraima and Rondonia highlands. A consistent east-west decline in biomass carbon in the Rio Negro Basin sector is associated with increasing rainfall and higher sand amounts. It is related to lesser C protection and greater C loss of sandy soils, subjected to active chemical leaching and widespread podzolization. Also, these soils possess lower cation exchangeable capacity and lower water retention capacity. Zones where deeply weathered Latosols dominate have a overall pattern of high C sequestration, and greater than the shallower soils from the upper Amazon, west of Madeira and Negro rivers. This was attributed to deeper incorporation of carbon in these clayey and highly pedo-bioturbated soils. The results highlight the urgent need for refining soil data at an appropriate scale for C stocks calculations purposes in Amazonia. There is a risk of misinterpreting C stocks in Amazonia when such great pedological variability is not taken into account. PMID:17846909
16. An ecological approach to the assessment of vegetation cover on inactive uranium mill tailings sites
International Nuclear Information System (INIS)
Vascular plants have been collected from abandoned or inactive uranium mill tailings in three mining areas in Canada. The collection was evaluated to determine some characteristics of vegetation development and to identify the plants which will persist on the sites. A total of 170 species were identified. Many of the species are widely distributed in North America, none has been reported as rare in any of the locations from which they were collected. Species richness was highest on Bancroft sites and lowest on Uranium City sites, though values were variable between sites. Forty-four per cent of the total number of species were found on only a single site. Only seven species occurred on more than half of the tailings sites and in all three mining areas. There was no difference between amended and unamended sites in terms of either species richness or species composition. There was no apparent relationship between species richness and either site size, site age or amendment history. The results of this survey suggest that the uranium mill tailings sites are at an early stage of colonization where the seed input from surrounding areas and the heterogeneity of the sites are factors determining species composition and species richness. The fate of an individual once it has reached the site will be determined by its ability to establish on the sites. A perennial growth habit and the ability to expand clonally are important characteristics of the species on the tailings. Theistics of the species on the tailings. The species on the tailings are commonly found in a variety of habitats. Consistent with the observation that the tailings sites are at a stage of early colonization, we find that the few species widely distributed across sites are all characteristic pioneering species with wide environmental tolerances. These species included Populus tremuloides, P. balsamifera, Scirpus cyperinus, Equisetum arvense, Betula papyrifera, Achillea millefolium and Typha spp. The vegetation on the tailings is likely to be characterized by these species for a long period of time. (author)
17. Browsing preference and ecological carrying capacity of sambar deer (Cervus unicolor brookei) on secondary vegetation in forest plantation.
Science.gov (United States)
Ismail, Dahlan; Jiwan, Dawend
2015-02-01
The browsing preference and ecological carrying capacity (ECC) of sambar deer (Cervus unicolor brookei) in acacia plantations for management and conservation of the ecosystem were investigated at Sabal Forest Reserve in Sarawak, Malaysia. The identification of the species browsed by the sambar deer was based on an observation of the plant parts consumed. ECC estimation was based on body weight (BW) and the physiological stages of animals browsed in six fenced 4-ha paddocks. Sambar deer were found foraging on only 29 out of 42 species of secondary vegetation in the acacia plantation. The remaining species are too high for the deer to reach. Planted species, Shorea macrophylla are not palatable to the deer. This augurs well for the integration of sambar deer into shorea plantations. The most frequently exploited plants were Ficus spp. Sambar deer preferred woody species more than non-woody species and they are browser animals. By producing metabolizable energy of 19,000 to 27,000 MJ/ha, the ECC was five head/ha to 5.25 head/ha. Given its contribution to the conservation of wildlife and its capacity to sustain the ecosystem, the sambar deer integrated farming system offers a promising strategy for the future of tropical forestry management. PMID:25163638
18. An Ecological Study of Roadside Vegetation and Soils in Sahiwal District
Directory of Open Access Journals (Sweden)
K.F. Akbar
2003-01-01
Full Text Available The present study was carried out to investigate the floristic composition of roadside vegetation and levels of some heavy metals in roadside soils in Sahiwal district, Pakistan. Among sixty recorded species, the main grass species include Cynodon dactylon, Desmostachya bipinnata, Panicum turgidum, Cyperus rotundus and Cenchrus biflorus. The dominant species exhibited little variation between different zones of verges. Other species however, showed preferences for certain zones of the verges indicating differences in microhabitat conditions in the verges. The roadside soils were analysed for lead, copper, manganese and zinc levels. The amount of total lead, zinc, copper and manganese varied from 0.5 to 48.4, 37.7 to 109.9, 3.8 to 44.3 and 170 to 258.5 ? g g-1, respectively with a mean values of 9.4, 63.0, 31.4 and 218 ? g g-1. The levels of heavy metals in the roadside soils indicated that these soils were non-contaminated.
19. Vegetation ecology meets ecosystem science: Permanent grasslands as a functional biogeography case study.
Science.gov (United States)
Violle, Cyrille; Choler, Philippe; Borgy, Benjamin; Garnier, Eric; Amiaud, Bernard; Debarros, Guilhem; Diquelou, Sylvain; Gachet, Sophie; Jolivet, Claudy; Kattge, Jens; Lavorel, Sandra; Lemauviel-Lavenant, Servane; Loranger, Jessy; Mikolajczak, Alexis; Munoz, François; Olivier, Jean; Viovy, Nicolas
2015-11-15
The effect of biodiversity on ecosystem functioning has been widely acknowledged, and the importance of the functional roles of species, as well as their diversity, in the control of ecosystem processes has been emphasised recently. However, bridging biodiversity and ecosystem science to address issues at a biogeographic scale is still in its infancy. Bridging this gap is the primary goal of the emerging field of functional biogeography. While the rise of Big Data has catalysed functional biogeography studies in recent years, comprehensive evidence remains scarce. Here, we present the rationale and the first results of a country-wide initiative focused on the C3 permanent grasslands. We aimed to collate, integrate and process large databases of vegetation relevés, plant traits and environmental layers to provide a country-wide assessment of ecosystem properties and services which can be used to improve regional models of climate and land use changes. We outline the theoretical background, data availability, and ecoinformatics challenges associated with the approach and its feasibility. We provide a case study of upscaling of leaf dry matter content averaged at ecosystem level and country-wide predictions of forage digestibility. Our framework sets milestones for further hypothesis testing in functional biogeography and earth system modelling. PMID:25908020
20. The effect of vegetation type on selected soil quality indicators in a semiarid rangeland in Hamedan, Iran
Directory of Open Access Journals (Sweden)
Soheila Javaheri Khah
2015-01-01
Full Text Available Soil quality approach can be used to describe soil health changes caused by different land use managements and vegetation types. Our objective was to assess the response of some soil quality indicators to different vegetation types including rainfed wheat (RW, grasses (G, Astragallus-Bromus (A-B, Astragallus-Lactuca (A-L, Astragallus-Artimisia (A-A and Astragallus-Euphorbia (A-E in a semiarid experimental rangeland in Hamedan, where environmental conditions in terms of slope aspect and soil parent material were similar., Substrate-induced microbial respiration (MRI and the activity of phosphomonoesterase enzyme (PMEase were determined in surface soil (0-15 cm in spring and autumn. Morover, bioavailable phosphorus (P and potassium (K were measured in autumn. No significant disparity was detected in P content of different vegetation types. Bioavailable K between was highest in A-E, and lowest in G and RW sites. MRI was significantly higher in spring irrespective of vegetation type. This index was significantly highest in A-B site in both seasons. As for PMEase, A-A and A-B showed the highest values in autumn in spring, A-B, A-A and A-L demonstrated the highest phosphatase activity. PMEase in A-L and A-A sites was significantly higher in spring than autumn. Strongly significant positive correlation was found between PMEase and MRI. Overall, soil quality is highest under vegetation types composed of perennial shrubs, irrespective of season.
1. Hotspots of human-induced biomass productivity decline and their social-ecological types toward supporting national policy and local studies on combating land degradation
Science.gov (United States)
Vu, Quyet Manh; Le, Quang Bao; Vlek, Paul L. G.
2014-10-01
2. Expanding the Range of Plant Functional Diversity Represented in Global Vegetation Models: Towards Lineage-based Plant Functional Types
Science.gov (United States)
Still, C. J.; Griffith, D.; Edwards, E.; Forrestel, E.; Lehmann, C.; Anderson, M.; Craine, J.; Pau, S.; Osborne, C.
2014-12-01
Variation in plant species traits, such as photosynthetic and hydraulic properties, can indicate vulnerability or resilience to climate change, and feed back to broad-scale spatial and temporal patterns in biogeochemistry, demographics, and biogeography. Yet, predicting how vegetation will respond to future environmental changes is severely limited by the inability of our models to represent species-level trait variation in processes and properties, as current generation process-based models are mostly based on the generalized and abstracted concept of plant functional types (PFTs) which were originally developed for hydrological modeling. For example, there are close to 11,000 grass species, but most vegetation models have only a single C4 grass and one or two C3 grass PFTs. However, while species trait databases are expanding rapidly, they have been produced mostly from unstructured research, with a focus on easily researched traits that are not necessarily the most important for determining plant function. Additionally, implementing realistic species-level trait variation in models is challenging. Combining related and ecologically similar species in these models might ameliorate this limitation. Here we argue for an intermediate, lineage-based approach to PFTs, which draws upon recent advances in gene sequencing and phylogenetic modeling, and where trait complex variations and anatomical features are constrained by a shared evolutionary history. We provide an example of this approach with grass lineages that vary in photosynthetic pathway (C3 or C4) and other functional and structural traits. We use machine learning approaches and geospatial databases to infer the most important environmental controls and climate niche variation for the distribution of grass lineages, and utilize a rapidly expanding grass trait database to demonstrate examples of lineage-based grass PFTs. For example, grasses in the Andropogoneae are typically tall species that dominate wet and seasonally burned ecosystems, whereas Chloridoideae grasses are associated with semi-arid regions. These two C4 lineages are expected to respond quite differently to climate change, but are often modelled as a single PFT.
3. Fuel Consumption and Fire Emissions Estimates in Siberia: Impact of Vegetation Types, Meteorological Conditions, Forestry Practices and Fire Regimes
Science.gov (United States)
Kukavskaya, Elena; Conard, Susan; Ivanova, Galina; Buryak, Ludmila; Soja, Amber; Zhila, Sergey
2015-04-01
Boreal forests play a crucial role in carbon budgets with Siberian carbon fluxes and pools making a major contribution to the regional and global carbon cycle. Wildfire is the main ecological disturbance in Siberia that leads to changes in forest species composition and structure and in carbon storage, as well as direct emissions of greenhouse gases and aerosols to the atmosphere. At present, the global scientific community is highly interested in quantitative and accurate estimates of fire emissions. Little research on wildland fuel consumption and carbon emission estimates has been carried out in Russia until recently. From 2000 to 2007 we conducted a series of experimental fires of varying fireline intensity in light-coniferous forest of central Siberia to obtain quantitative and qualitative data on fire behavior and carbon emissions due to fires of known behavior. From 2009 to 2013 we examined a number of burned logged areas to assess the potential impact of forest practices on fire emissions. In 2013-2014 burned areas in dark-coniferous and deciduous forests were examined to determine fuel consumption and carbon emissions. We have combined and analyzed the scarce data available in the literature with data obtained in the course of our long-term research to determine the impact of various factors on fuel consumption and to develop models of carbon emissions for different ecosystems of Siberia. Carbon emissions varied drastically (from 0.5 to 40.9 tC/ha) as a function of vegetation type, weather conditions, anthropogenic effects and fire behavior characteristics and periodicity. Our study provides a basis for better understanding of the feedbacks between wildland fire emissions and changing anthropogenic disturbance patterns and climate. The data obtained could be used by air quality agencies to calculate local emissions and by managers to develop strategies to mitigate negative smoke impacts on the environmentand human health.
4. Inclusion of ecologically based trait variation in plant functional types reduces the projected land carbon sink in an earth system model.
Science.gov (United States)
Verheijen, Lieneke M; Aerts, Rien; Brovkin, Victor; Cavender-Bares, Jeannine; Cornelissen, Johannes H C; Kattge, Jens; van Bodegom, Peter M
2015-08-01
Earth system models demonstrate large uncertainty in projected changes in terrestrial carbon budgets. The lack of inclusion of adaptive responses of vegetation communities to the environment has been suggested to hamper the ability of modeled vegetation to adequately respond to environmental change. In this study, variation in functional responses of vegetation has been added to an earth system model (ESM) based on ecological principles. The restriction of viable mean trait values of vegetation communities by the environment, called 'habitat filtering', is an important ecological assembly rule and allows for determination of global scale trait-environment relationships. These relationships were applied to model trait variation for different plant functional types (PFTs). For three leaf traits (specific leaf area, maximum carboxylation rate at 25 °C, and maximum electron transport rate at 25 °C), relationships with multiple environmental drivers, such as precipitation, temperature, radiation, and CO2 , were determined for the PFTs within the Max Planck Institute ESM. With these relationships, spatiotemporal variation in these formerly fixed traits in PFTs was modeled in global change projections (IPCC RCP8.5 scenario). Inclusion of this environment-driven trait variation resulted in a strong reduction of the global carbon sink by at least 33% (2.1 Pg C yr(-1) ) from the 2nd quarter of the 21st century onward compared to the default model with fixed traits. In addition, the mid- and high latitudes became a stronger carbon sink and the tropics a stronger carbon source, caused by trait-induced differences in productivity and relative respirational costs. These results point toward a reduction of the global carbon sink when including a more realistic representation of functional vegetation responses, implying more carbon will stay airborne, which could fuel further climate change. PMID:25611824
5. Effects of storage time and temperature on the characteristics of vegetable-type soybean grain minimally processed
Scientific Electronic Library Online (English)
Karina, Czaikoski; Mercedes Concórdia, Carrão-Panizzi; Josemeyre Bonifácio da, Silva; Elza Iouko, Ida.
2012-08-01
Full Text Available The objective of this study was to evaluate the effects of storage time and temperature on the characteristics of vegetable-type soybean grain (cultivar BRS 267) minimally processed and to define the best conditions for its storage. The evaluation was performed by measurement of vitamin C levels, we [...] ight loss and color parameters (L*, a*, and b*). The time of storage of vegetable-type soybean grains minimally processed and storage in Styrofoam trays and wrapped with PVC film, caused a decreased in vitamin C levels and color parameters and increased weight loss. This process was intensified with higher temperature at 25 °C than 5°C. To maintain appropriate levels of vitamin C, weight and color of vegetable-type soybean grains minimally processed and storage in trays wrapped in plastic wrap, recommended storage for 3 days at 5°C.
6. Diversification of Nitrogen Sources in Various Tundra Vegetation Types in the High Arctic
Science.gov (United States)
Skrzypek, Grzegorz; Wojtu?, Bronis?aw; Richter, Dorota; Jakubas, Dariusz; Wojczulanis-Jakubas, Katarzyna; Samecka-Cymerman, Aleksandra
2015-01-01
Low nitrogen availability in the high Arctic represents a major constraint for plant growth, which limits the tundra capacity for carbon retention and determines tundra vegetation types. The limited terrestrial nitrogen (N) pool in the tundra is augmented significantly by nesting seabirds, such as the planktivorous Little Auk (Alle alle). Therefore, N delivered by these birds may significantly influence the N cycling in the tundra locally and the carbon budget more globally. Moreover, should these birds experience substantial negative environmental pressure associated with climate change, this will adversely influence the tundra N-budget. Hence, assessment of bird-originated N-input to the tundra is important for understanding biological cycles in polar regions. This study analyzed the stable nitrogen composition of the three main N-sources in the High Arctic and in numerous plants that access different N-pools in ten tundra vegetation types in an experimental catchment in Hornsund (Svalbard). The percentage of the total tundra N-pool provided by birds, ranged from 0–21% in Patterned-ground tundra to 100% in Ornithocoprophilous tundra. The total N-pool utilized by tundra plants in the studied catchment was built in 36% by birds, 38% by atmospheric deposition, and 26% by atmospheric N2-fixation. The stable nitrogen isotope mixing mass balance, in contrast to direct methods that measure actual deposition, indicates the ratio between the actual N-loads acquired by plants from different N-sources. Our results enhance our understanding of the importance of different N-sources in the Arctic tundra and the used methodological approach can be applied elsewhere. PMID:26376204
7. Simulating fire-induced ecological succession with the dynamically coupled fire-vegetation model, ED-SPIFTIRE
Science.gov (United States)
Spessa, A.; Fisher, R.
2009-04-01
The simulation of fire-vegetation feedbacks is crucial for determining fire-induced changes to ecosystem structure and function, and emissions of trace gases and aerosols under future climate change. A new global fire model SPITFIRE (SPread and InTensity of FIRE) has been designed to overcome many of the limitations in existing fire models set within DGVM frameworks (Thonicke et al. 2008). SPITFIRE has been applied in coupled mode globally (Thonicke et al. 2008) and northern Australia (Spessa et al. unpubl.) as part of the LPJ DGVM. It has also been driven with MODIS burnt area data applied to sub-Saharan Africa (Lehsten et al. 2008) as part of the LPJ-GUESS vegetation model (Smith et al. 2001). Recently, Spessa & Fisher (unpubl.) completed the coupling of SPIFTIRE to the Ecosystem Demography (ED) model (Moorecroft et al. 2001), which has been globalised by Dr R. Fisher as part of the development of the new land surface scheme JULES (Joint UK Environment Simulator) within the QUEST Earth System Model (http://www.quest-esm.ac.uk/). In contrast to the LPJ DGVM, ED is a ‘size and age structured' approximation of an individual based gap model. The major innovation of the ED-SPITFIRE model compared with LPJ-SPITFIRE is the categorisation of each climatic grid cell into a series of non-spatially contiguous patches which are defined by a common ‘age since last disturbance'. In theory, the age-class structure of ED facilitates ecologically realistic processes of succession and re-growth to be represented. By contrast, LPJ DGVM adopts an ‘area-based approach' that implicitly averages individual and patch differences across a wider area and across ‘populations' of PFTs. This presentation provides an overview of SPITFIRE, and provides preliminary results from ED-SPITFIRE applied to northern Australian savanna ecosystems which, due to spatio-temporal variation in fire disturbance, comprise a patchwork of grasses and trees at different stages of post-fire succession. Comparisons with similar simulations undertaken with LPJ-SPITFIRE are also presented.
8. High intake of fruit and vegetables is related to low oxidative stress and inflammation in a group of patients with type 2 diabetes
OpenAIRE
Åsgård, Rikard; Rytter, Elisabet; Basu, Samar; Abramsson-Zetterberg, Lilianne; Möller, Lennart; Vessby, Bengt
2007-01-01
Background : Patients with type 2 diabetes have increased levels of oxidative stress and inflammation. A high fruit and vegetable intake may be beneficial. Objective : To study whether fruit and vegetable intake and levels of plasma antioxidants relate to markers of oxidative stress and inflammation in a group of patients with type 2 diabetes. Further, to investigate whether plasma antioxidants are good biomarkers for intake of fruit and vegetables. Design : Patients with type 2 diabetes were...
9. Evaluating the Usefulness of High-Temporal Resolution Vegetation Indices to Identify Crop Types
Science.gov (United States)
Hilbert, K.; Lewis, D.; O'Hara, C. G.
2006-12-01
The National Aeronautical and Space Agency (NASA) and the United States Department of Agriculture (USDA) jointly sponsored research covering the 2004 to 2006 South American crop seasons that focused on developing methods for the USDA's Foreign Agricultural Service's (FAS) Production Estimates and Crop Assessment Division (PECAD) to identify crop types using MODIS-derived, hyper-temporal Normalized Difference Vegetation Index (NDVI) images. NDVI images were composited in 8 day intervals from daily NDVI images and aggregated to create a hyper-termporal NDVI layerstack. This NDVI layerstack was used as input to image classification algorithms. Research results indicated that creating high-temporal resolution Normalized Difference Vegetation Index (NDVI) composites from NASA's MODerate Resolution Imaging Spectroradiometer (MODIS) data products provides useful input to crop type classifications as well as potential useful input for regional crop productivity modeling efforts. A current NASA-sponsored Rapid Prototyping Capability (RPC) experiment will assess the utility of simulated future Visible Infrared Imager / Radiometer Suite (VIIRS) imagery for conducting NDVI-derived land cover and specific crop type classifications. In the experiment, methods will be considered to refine current MODIS data streams, reduce the noise content of the MODIS, and utilize the MODIS data as an input to the VIIRS simulation process. The effort also is being conducted in concert with an ISS project that will further evaluate, verify and validate the usefulness of specific data products to provide remote sensing-derived input for the Sinclair Model a semi-mechanistic model for estimating crop yield. The study area encompasses a large portion of the Pampas region of Argentina--a major world producer of crops such as corn, soybeans, and wheat which makes it a competitor to the US. ITD partnered with researchers at the Center for Surveying Agricultural and Natural Resources (CREAN) of the National University of Cordoba, Argentina, and CREAN personnel collected and continue to collect field-level, GIS-based in situ information. Current efforts involve both developing and optimizing software tools for the necessary data processing. The software includes the Time Series Product Tool (TSPT), Leica's ERDAS Imagine, and Mississippi State University's Temporal Map Algebra computational tools.
10. Lake Bathymetric Aquatic Vegetation
Minnesota Department of Natural Resources — Aquatic vegetation represented as polygon features, coded with vegetation type (emergent, submergent, etc.) and field survey date. Polygons were digitized from...
11. Environment effects on wood density of vegetation types in Minas Gerais State – Brazil
Directory of Open Access Journals (Sweden)
Antônio Donizette de Oliveira
2012-06-01
Full Text Available The objective was to verify the general behavior of wood density of native tree species in forest types in Minas Gerais state. The trees scaling data were obtained from the Forest Inventory of Minas Gerais State. Were used data from 1988 trees distributed in different forest formations. From each tree, five discs of wood were removed, at the 0, 25, 50, 75 and 100% of the total height. The wood basic density of each disk was determined according to NBR 7190/1997. The ombrophylous forest, semideciduous forest, savanna woodland, typical savanna and deciduous forest presented average wood density of 0.502, 0.561, 0.585, 0.612 and 0.675 g.cm-3, respectively, all statistically different. It was found a clear and consistent relation between wood density and environment characteristics that affect the different vegetation types in Minas Gerais State. The forest formations present environmental conditions so typical that they affect the floristic composition and also the cambial and physiological activity of plants, causing particular wood densities to forests formations.
12. Social Ecological Model of Illness Management in High-Risk Youths with Type 1 Diabetes
Science.gov (United States)
Naar-King, Sylvie; Podolski, Cheryl-Lynn; Ellis, Deborah A.; Frey, Maureen A.; Templin, Thomas
2006-01-01
In this study, the authors tested a social ecological model of illness management in high-risk, urban adolescents with Type 1 diabetes. It was hypothesized that management behaviors would be associated with individual adolescent characteristics as well as family, peer, and provider relationships. Questionnaires were collected from 96 adolescents…
13. [Variation of soil organic carbon under different vegetation types in Karst Mountain areas of Guizhou Province, southwest China].
Science.gov (United States)
Liao, Hong-kai; Long, Jian
2011-09-01
This paper studied the variation characteristics of soil organic carbon (SOC) and different particle sizes soil particulate organic carbon (POC) in normal soil and in micro-habitats under different vegetation types in typical Karst mountain areas of southwest Guizhou. Under different vegetation types, the SOC content in normal soil and in micro-habitats was all in the order of bare land < grass < shrub < forest, with the variation range being 7.18-43.42 g x kg(-1) in normal soil and being 6.62-46.47 g x kg(-1) and 9.01-52.07 g x kg(-1) in earth surface and stone pit, respectively. The POC/MOC (mineral-associated organic carbon) ratio under different vegetation types was in the order of bare land < grass < forest < shrub. Under the same vegetation types, the POC/MOC in stone pit was the highest, as compared to that in normal soil and in earth surface. In the process of bare land-grass-shrub-forest, the contents of different particle sizes soil POC increased, while the SOC mainly existed in the forms of sand- and silt organic carbon, indicating that in Karst region, soil carbon sequestration and SOC stability were weak, soil was easily subjected to outside interference and led to organic carbon running off, and thus, soil quality had the risk of decline or degradation. PMID:22126032
14. Regular, high, and moderate intake of vegetables rich in antioxidants may reduce cataract risk in Central African type 2 diabetics
Directory of Open Access Journals (Sweden)
Mvitu M
2012-06-01
Full Text Available Moise Mvitu,1 Benjamin Longo-Mbenza,2 Dieudonné Tulomba,3 Augustin Nge31Department of Ophthalmology, University of Kinshasa, Democratic Republic of Congo; 2Faculty of Health Sciences, Walter Sisulu University, South Africa; 3Biostatistics Unit, Lomo Medical Center and Heart of Africa Center of Cardiology, Kinshasa, Democratic Republic of CongoBackground: Antioxidant nutrients found in popularly consumed vegetables, including red beans, are thought to prevent diabetic complications. In this study, we assessed the frequency and contributing factors of intake of fruits and vegetables rich in antioxidants, and we determined their impact on the prevention of diabetes-related cataract extraction.Methods: This was a cross-sectional study, run in Congo among 244 people with type 2 diabetes mellitus. An intake of ?three servings of vegetables rich in antioxidants/day, intake of red beans, consumption of fruit, and cataract extraction were considered as dependent variables.Results: No patient reported a fruit intake. Intake of red beans was reported by 64 patients (26.2%, while 77 patients (31.6% reported ?three servings of vegetables rich in antioxidants. High socioeconomic status (OR = 2.3; 95% CI: 1.1–12.5; P = 0.030 and moderate alcohol intake (OR = 4; 95% CI: 1.1–17.4; P = 0.049 were the independent determinants of eating ?three servings of vegetables rich in antioxidants. Red beans intake (OR = 0.282; 95% CI: 0.115–0.687; P > 0.01 and eating ?three servings of vegetables rich in antioxidants (OR = 0.256; 95% CI: 0.097–0.671; P = 0.006 were identified as independent and protective factors against the presence of cataracts (9.8% n = 24, whereas type 2 diabetes mellitus duration ?3 years was the independent risk factor for cataract extraction (OR = 6.3; 95% CI: 2.1–19.2; P > 0.001 in the model with red beans intake and OR = 7.1; 95% CI: 2.3–22.2; P > 0.001 in the model with ?three servings of vegetables rich in antioxidants.Conclusion: Red beans intake and adequate quantity of intake of vegetables rich in antioxidants were found to be associated with reduced risk of cataract in these Congolese with type 2 diabetes mellitus. Education on nutrition and health promotion programs are needed to encourage people to eat vegetables and fruit.Keywords: red beans, cataract extraction, socioeconomic status, public health implications
15. Plant Traits Demonstrate That Temperate and Tropical Giant Eucalypt Forests Are Ecologically Convergent with Rainforest Not Savanna
OpenAIRE
Tng, David Y. P.; Jordan, Greg J.; Bowman, David M J S
2013-01-01
Ecological theory differentiates rainforest and open vegetation in many regions as functionally divergent alternative stable states with transitional (ecotonal) vegetation between the two forming transient unstable states. This transitional vegetation is of considerable significance, not only as a test case for theories of vegetation dynamics, but also because this type of vegetation is of major economic importance, and is home to a suite of species of conservation significance, including the...
16. On the potential vegetation feedbacks that enhance phosphorus availability – insights from a process-based model linking geological and ecological timescales
Directory of Open Access Journals (Sweden)
C. Buendía
2014-07-01
We find that active P uptake is an essential mechanism for sustaining P availability on long timescales, whereas biotic de-occlusion might serve as a buffer on timescales shorter than 10 000 yr. Although active P uptake is essential for reducing P losses by leaching, humid lowland soils reach P limitation after around 100 000 yr of soil evolution. Given the generalized modelling framework, our model results compare reasonably with observed or independently estimated patterns and ranges of P concentrations in soils and vegetation. Furthermore, our simulations suggest that P limitation might be an important driver of biomass production efficiency (the fraction of the gross primary productivity used for biomass growth, and that vegetation on old soils has a smaller biomass production rate when P becomes limiting. With this study, we provide a theoretical basis for investigating the responses of terrestrial ecosystems to P availability linking geological and ecological timescales under different environmental settings.
17. Ecological restoration and recovery in the wind-blown sand hazard areas of northern China: relationship between soil water and carrying capacity for vegetation in the Tengger Desert.
Science.gov (United States)
Li, XingRong; Zhang, ZhiShan; Tan, HuiJuan; Gao, YanHong; Liu, LiChao; Wang, XingPing
2014-05-01
The main prevention and control area for wind-blown sand hazards in northern China is about 320000 km(2) in size and includes sandlands to the east of the Helan Mountain and sandy deserts and desert-steppe transitional regions to the west of the Helan Mountain. Vegetation recovery and restoration is an important and effective approach for constraining wind-blown sand hazards in these areas. After more than 50 years of long-term ecological studies in the Shapotou region of the Tengger Desert, we found that revegetation changed the hydrological processes of the original sand dune system through the utilization and space-time redistribution of soil water. The spatiotemporal dynamics of soil water was significantly related to the dynamics of the replanted vegetation for a given regional precipitation condition. The long-term changes in hydrological processes in desert areas also drive replanted vegetation succession. The soil water carrying capacity of vegetation and the model for sand fixation by revegetation in aeolian desert areas where precipitation levels are less than 200 mm are also discussed. PMID:24699917
18. An ecological study of the major vegetation communities of the Vaalbos National Park, Northern Cape. 2. The Graspan-Holpan section
Directory of Open Access Journals (Sweden)
H. Bezuidenhout
1995-09-01
Full Text Available Detailed classification, description and mapping of the Graspan-Holpan section of the Vaalbos National Park, Northern Cape, were initiated. This classification is intended to serve as a basis for the establishment of an efficient wildlife management programme as well as conservation policies for the Vaalbos National Park. Using a numerical classification technique (TWINSPAN as a first approximation, the classification was refined by applying Braun-Blanquet procedures. A hierarchical plant community clas- sification, description, ecological interpretation and a vegetation map are presented. In the phytosociological table nine major plant communities are recognised.
19. Ecological aspects of lake regulation in Northern Finland. Part 2. Geomorphology and vegetation of the littoral zone. Ekologiset naekoekohdat joidenkin Pohjois-Suomen jaervien saeaennoestelyssae. Osa 2. Rannan geomorfologia ja vesikasvillisuus
Energy Technology Data Exchange (ETDEWEB)
Hellsten, S.; Alasaarela, E. (9830800FI); Keraenen, R.; Nykaenen, M. (Oulu Univ. (Finland)); Neuvonen, I. (Kainuun Vesi- ja ympaeristoepiiri, Kajaani (Finland))
1989-02-01
Ecological aspects of lake regulation were studied in certain lakes in northern Finland in 1984-1987. The general aims of the project were to analyze the effects of regulation on lake ecosystems and to produce information that can be applied when assessing the possible effects of hydroelectric projects. The effects of lake regulation were easy to observe in the littoral zone of Lake Ontojaervi, the sandy shores in particular were unstable both above and below the water level. The shores were very much steeper than those of Lake Lentua, which affected the distribution of bottom types, minerogenic bottoms were more common than in the latter lake. The results from the two lakes were used to calculate a simple model to forecast the distribution of bottom types of Lake Ontojaervi before regulation. The effect of penetration by ice was also easy to recognize on the shores of Lake Ontojaervi; the surface sediment being frozen to a greater depth than in Lake Lentua. Beneath the freezing zone in ice just pressed down on the sediment. The littoral vegetation decreased markedly after regulation and was entirely absent in open places. Changes in abundance were particularly clear, with decreases in the large isoetides and helophytes and increases of small isoetides. The results from Lake Lentua were used to formulate a simple ecological model for the frequency of macrophytes.
20. Biodiesel classification by base stock type (vegetable oil) using near infrared spectroscopy data
Energy Technology Data Exchange (ETDEWEB)
Balabin, Roman M., E-mail: [email protected] [Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich (Switzerland); Safieva, Ravilya Z. [Gubkin Russian State University of Oil and Gas, 119991 Moscow (Russian Federation)
2011-03-18
The use of biofuels, such as bioethanol or biodiesel, has rapidly increased in the last few years. Near infrared (near-IR, NIR, or NIRS) spectroscopy (>4000 cm{sup -1}) has previously been reported as a cheap and fast alternative for biodiesel quality control when compared with infrared, Raman, or nuclear magnetic resonance (NMR) methods; in addition, NIR can easily be done in real time (on-line). In this proof-of-principle paper, we attempt to find a correlation between the near infrared spectrum of a biodiesel sample and its base stock. This correlation is used to classify fuel samples into 10 groups according to their origin (vegetable oil): sunflower, coconut, palm, soy/soya, cottonseed, castor, Jatropha, etc. Principal component analysis (PCA) is used for outlier detection and dimensionality reduction of the NIR spectral data. Four different multivariate data analysis techniques are used to solve the classification problem, including regularized discriminant analysis (RDA), partial least squares method/projection on latent structures (PLS-DA), K-nearest neighbors (KNN) technique, and support vector machines (SVMs). Classifying biodiesel by feedstock (base stock) type can be successfully solved with modern machine learning techniques and NIR spectroscopy data. KNN and SVM methods were found to be highly effective for biodiesel classification by feedstock oil type. A classification error (E) of less than 5% can be reached using an SVM-based approach. If computational time is an important consideration, the KNN technique (E = 6.2%) can be recommended for practical (industrial) implementation. Comparison with gasoline and motor oil data shows the relative simplicity of this methodology for biodiesel classification.
1. Biodiesel classification by base stock type (vegetable oil) using near infrared spectroscopy data
International Nuclear Information System (INIS)
The use of biofuels, such as bioethanol or biodiesel, has rapidly increased in the last few years. Near infrared (near-IR, NIR, or NIRS) spectroscopy (>4000 cm-1) has previously been reported as a cheap and fast alternative for biodiesel quality control when compared with infrared, Raman, or nuclear magnetic resonance (NMR) methods; in addition, NIR can easily be done in real time (on-line). In this proof-of-principle paper, we attempt to find a correlation between the near infrared spectrum of a biodiesel sample and its base stock. This correlation is used to classify fuel samples into 10 groups according to their origin (vegetable oil): sunflower, coconut, palm, soy/soya, cottonseed, castor, Jatropha, etc. Principal component analysis (PCA) is used for outlier detection and dimensionality reduction of the NIR spectral data. Four different multivariate data analysis techniques are used to solve the classification problem, including regularized discriminant analysis (RDA), partial least squares method/projection on latent structures (PLS-DA), K-nearest neighbors (KNN) technique, and support vector machines (SVMs). Classifying biodiesel by feedstock (base stock) type can be successfully solved with modern machine learning techniques and NIR spectroscopy data. KNN and SVM methods were found to be highly effective for biodiesel classification by feedstock oil type. A classification error (E) of less than 5% can be reached using an SVM-based approach. If computational time is an important consideration, the KNN technique (E = 6.2%) can be recommended for practical (industrial) implementation. Comparison with gasoline and motor oil data shows the relative simplicity of this methodology for biodiesel classification.
2. Comparison of interception and initial retention of wet-deposited contaminants on leaves of different vegetation types
Science.gov (United States)
Owen Hoffman, F.; Thiessen, Kathleen M.; Rael, Rolando M.
Simulated rain containing both soluble radionuclides and insoluble particles labeled with a radionuclide was manually applied to several kinds of vegetation, including a conifer, a broad-leafed tree, and several herbaceous species. The fraction of each radioactive material intercepted and initially retained by the vegetation was determined for each plant type. This fraction was determined both as the mass interception factor, r/Y, and the leaf area interception fraction, LAIF. Mean values of r/Y ranged from 0.16 to 2.9 m 2 kg -1 and of the LAIF, from 0.011 to 0.16. There was a greater range in mean retention values among radionuclide types than among plant species; the range among plant types tended to be less with the LAIF than the r/Y. Significantly less interception and initial retention was measured for anions than for cations or the insoluble particles.
3. Detection of Helicobacter pylori in Various Types of Vegetables and Salads
Directory of Open Access Journals (Sweden)
2008-05-01
Full Text Available Background:: There is a possibility for the presence of Helicobacter pylori in vegetables due to their close contact with polluted water, soil and feces. Objectives:: This study was carried out to detect the presence of H. pylori in vegetables and salads in Iran. Materials and Methods:: In total, 460 vegetable and salad samples were collected and transferred immediately to the laboratory. All samples were cultured and tested for the presence of H. pylori using the Polymerase Chain Reaction technique. Results:: The results showed that 44 of 460 samples (9.56% were positive for H. pylori using the culture method. The Polymerase Chain Reaction technique showed that 50 of 460 samples (10.86% were positive for H. pylori. Un-washed leek, traditional salad, un-washed basil and un-washed lettuce were the most commonly contaminated samples. The presence of the bacteria in various vegetables was statistically significant (P < 0.05. Conclusions:: Vegetables are a new source of H. pylori and accurate washing of vegetables improves such contaminations. Keywords: Helicobacter pylori; Vegetables; Culture; Polymerase Chain Reaction
4. Seasat synthetic aperture radar ( SAR) response to lowland vegetation types in eastern Maryland and Virginia.
Science.gov (United States)
Krohn, M.D.; Milton, N.M.; Segal, D.B.
1983-01-01
Examination of Seasat SAR images of eastern Maryland and Virginia reveals botanical distinctions between vegetated lowland areas and adjacent upland areas. Radar returns from the lowland areas can be either brighter or darker than returns from the upland forests. Scattering models and scatterometer measurements predict an increase of 6 dB in backscatter from vegetation over standing water. This agrees with the 30-digital number (DN) increase observed in the digital Seasat data. The density, morphology, and relative geometry of the lowland vegetation with respect to standing water can all affect the strength of the return L band signal.-from Authors
5. In situ burning of oil in coastal marshes. 1. Vegetation recovery and soil temperature as a function of water depth, oil type, and marsh type.
Science.gov (United States)
Lin, Qianxin; Mendelssohn, Irving A; Bryner, Nelson P; Walton, William D
2005-03-15
In-situ burning of oiled wetlands potentially provides a cleanup technique that is generally consistent with present wetland management procedures. The effects of water depth (+10, +2, and -2 cm), oil type (crude and diesel), and oil penetration of sediment before the burn on the relationship between vegetation recovery and soil temperature for three coastal marsh types were investigated. The water depth over the soil surface during in-situ burning was a key factor controlling marsh plant recovery. Both the 10- and 2-cm water depths were sufficient to protect marsh vegetation from burning impacts, with surface soil temperatures of Distichlis spicata. Oil type (crude vs diesel) and oil applied to the marsh soil surface (0.5 L x m(-2)) before the burn did not significantly affect plant recovery. Thus, recovery is species-specific when no surface water exists. Even water at the soil surface will most likely protect wetland plants from burning impact. PMID:15819246
6. Spatial Vegetation Data for Colorado National Monument Vegetation Mapping Project
National Park Service, Department of the Interior — The vegetation units on this map were determined through a series of image processing steps including unsupervised classification, ecological modeling and...
7. Vegetation Cover Types of St. Vincent Island N.W.R.
US Fish and Wildlife Service, Department of the Interior — The objectives of this vegetative study on St. Vincent National Wildlife Refuge were to: 1 identify and describe the major plant communities and associations on the...
8. Soil permeability as a function of vegetation type and soil water content
International Nuclear Information System (INIS)
Soil permeability is important for estimating the rate of mass transport of 222Rn through soils and into basements. We measured permeability and soil water content on a set of nine plots consisting of three plots vegetated with common barley (Hordeum vulgare), three plots vegetated with Russian thistle (Salsola kali), and three bare plots. Soil moisture was consistently highest on the bare plots and lowest on the Russian thistle plots. Plots with vegetation had lower soil water content during the growing season. Permeability was consistently higher on Russian thistle plots. ANOVA showed that both soil water content and presence of Russian thistle had a significant impact on permeability but that presence of barley did not. The effect of vegetation and moisture on permeability may have significant effects on 222Rn transport in soils. 18 refs., 8 figs., 1 tab
9. Wieslander Vegetation
California Department of Resources — Digital version of the 1945 California Vegetation Type Maps by A. E. Wieslander of the U.S. Forest Service. Source scale of maps are 1:100,000. These compiled maps...
10. Estado ecológico de ríos y vegetación ribereña en el contexto de la nueva Ley General de Aguas de México / Ecological status of rivers and riparian vegetation within the new General Mexican Water's Law context
Scientific Electronic Library Online (English)
Mayra, MENDOZA CARIÑO; Abel, QUEVEDO NOLASCO; Ángel, BRAVO VINAJA; Héctor, FLORES MAGDALENO; María de Lourdes, DE LA ISLA DE BAUER; Francisco, GAVI REYES; Bertha Patricia, ZAMORA MORALES.
Full Text Available Los ríos son unidades vitales en el funcionamiento de las cuencas que, debido al transporte y a la circulación cíclica del agua, permiten la existencia de los seres vivos. Poseen gran valor ecológico y ambiental dada su influencia sobre otros ecosistemas y los beneficios que proporcionan al hombre, [...] tanto para consumo como para riego y uso en los ámbitos agrícola e industrial. Sin embargo, casi todos los ríos de México presentan algún tipo de deterioro. Alrededor de 73 % de los sistemas acuáticos muestran contaminación, lo que empobrece la salud de estos ecosistemas. El objetivo de este trabajo es proponer que en la formulación de la nueva ley general de aguas se considere la regulación de la vegetación ribereña, pues su influencia en el mantenimiento y en la rehabilitación del estado ecológico de los ríos es fundamental. Se sugiere que la nueva ley contenga una sección de protección ambiental en la que se incluya a la vegetación ribereña como elemento clave para proteger, conservar y restaurar los ríos. Asimismo, que la delimitación de dicha vegetación se apegue a las condiciones naturales de inundación del cauce, con una frecuencia de una vez cada ocho años, de acuerdo con la variabilidad del flujo. Además, su manejo debe tomar en cuenta la reforestación y el mantenimiento de especies vegetales nativas de cada región. Abstract in english Rives are vital units in the functioning of the watersheds that, due to the transportation and circulation of water, allow the existence of life. They are of great ecological and environmental value because of their influence on other ecosystems as well as the benefits they give to humankind, not on [...] ly in the consumption for irrigation but also in the use in the agricultural and industrial areas. However, almost all the rivers in Mexico show a certain type of deterioration. About 70 % of the aquatic systems shows contamination which diminishes the health of these ecosystems. The objective of this work is to propose that the riparian vegetation should be included in the making of the new general law of water because its influence on the maintenance and rehabilitation of the ecological state of rivers is fundamental. It has been suggested a new law that contains a section of environmental protection which includes the riparian vegetation as a key element to protect, preserve, and restore rivers. Likewise, the boundaries of this vegetation should be according to the natural conditions of flooding in the bed of the river, with a once-in-every eight years- frequency, according to the variability of flow. In addition, its handling must consider the reforestation and maintenance of native vegetation species in each region.
11. Crestridge Vegetation Map [ds211
California Department of Resources — This layer represents vegetation communities in the Department of Fish and Game's Crestridge Ecological Reserve. The County of San Diego, the Conservation Biology...
12. Ecology of Nematodes Under Influence of Cucurbita spp. and Different Fertilizer Types
OpenAIRE
Porazinska, D.L.; COLEMAN, D.C.
1995-01-01
In a field study conducted in Georgia, cucurbit plants with high (Cucurbita andreana) and low (Cucurbita maxima) concentrations of cucurbitacins were used in combination with two types of fertilizers to investigate their effects on the community of soil nematodes. Ecological measures of soil nematode community structure such as total nematode abundance, number of genera, trophic diversity, trophic group proportions, fungivore/bacterivore ratio, and modified maturity index were assessed and co...
13. Investigating mechanisms maintaining plant species diversity in fire prone Mediterranean-type vegetation using spatially-explicit simulation models
OpenAIRE
Esther, Alexandra
2010-01-01
Fire prone Mediterranean-type vegetation systems like those in the Mediterranean Basin and South-Western Australia are global hot spots for plant species diversity. To ensure management programs act to maintain these highly diverse plant communities, it is necessary to get a profound understanding of the crucial mechanisms of coexistence. In the current literature several mechanisms are discussed. The objective of my thesis is to systematically explore the importance of potential mechanisms f...
14. The impact of parent material, climate, soil type and vegetation on Venetian forest humus forms: a direct gradient approach
OpenAIRE
Ponge, Jean-François; Sartori, Giacomo; Garlato, Adriano; UNGARO, FABRIZIO; Zanella, Augusto; Jabiol, Bernard; Obber, Silvia
2014-01-01
The impact of geology, climate, soil type and vegetation on forest humus forms was studied in the Veneto Region (northern Italy). A total of 352 study sites were compared by Redundancy Analysis (RDA). Humus forms were described by the structure (micro-, meso-, or macro-aggregated) of the organo-mineral A horizon, by the thickness of litter horizons and by their nomenclature, which followed the morpho-functional classification recently proposed for inclusion in the WRB-FAO. The size of aggrega...
15. Variation in Protein Content and Amino Acids in the Leaves of Grain, Vegetable and Weedy Types of Amaranths
OpenAIRE
Ryo Ohsawa; Shigeki Yoshida; Rita Andini
2013-01-01
Malnutrition has affected almost 31% of pre-school children. This paper provides the information of nutritional values (leaf protein, 15 amino acids, biomass and leaf dry matter) of grain, vegetable and weedy types of amaranths (n = 76 accessions); particularly those novel materials originated from the highland areas of Sumatra-Takengon. The highest values of leaf protein and total amino acids were found in many weedy species (A. viridis, A. blitum L. and A. dubius). The ranges of leaf protei...
16. Some pathogenetic aspects of influence of ecological factors on the vegetative and haemodynamic status at children of Belarus
International Nuclear Information System (INIS)
The paradoxal sympathic vegetative regulation of central haemodynamice and the fall of basal activity of sympathoadrenal system at children under the combination chronic radio-chemical influence were established
17. Impact of vegetation types on soil organic carbon stocks SOC-S in Mediterranean natural areas
Science.gov (United States)
Parras-Alcántara, Luis; Lozano-García, Beatriz; Cantudo-Pérez, Marta
2015-04-01
Soils play a key role in the carbon geochemical cycle because they can either emit large quantities of CO2 or on the contrary they can act as a store for carbon. Agriculture and forestry are the only activities that can achieve this effect through photosynthesis and the carbon incorporation into carbohydrates (Parras-Alcántara et al., 2013). The Mediterranean evergreen oak Woodland (MEOW - dehesa) is a type of pasture with scattered evergreen and deciduous oak stands in which cereals are often grown under the tree cover. It is a system dedicated to the combined production of Iberian swine, sheep, fuel wood, coal and cork as well as to hunting. These semi-natural areas still preserve some of the primitive vegetation of the Mediterranean oak forests. The dehesa is a pasture where the herbaceous layer is comprised of either cultivated cereals such as oat, barley and wheat or native vegetation dominated by annual species, which are used as grazing resources. These Iberian open woodland rangelands (dehesas) have been studied from different points of view: hydrologically, with respect to soil organic matter content, as well as in relation to gully erosion, topographical thresholds, soil erosion and runoff production, soil degradation and management practices…etc, among others. The soil organic carbon stock capacity depends not only on abiotic factors such as the mineralogical composition and the climate, but also on soil use and management (Parras et al., 2014 and 2015). In Spanish soils, climate, use and management strongly affect the carbon variability, mainly in soils in dry Mediterranean climates characterized by low organic carbon content, weak structure and readily degradable soils. Hontoria et al. (2004) emphasized that the climate and soil use are two factors that greatly influence carbon content in the Mediterranean climate. This research sought to analyze the SOC stock (SOCS) variability in MEOW - dehesa with cereals, olive grove and Mediterranean oak forest with different vegetation types (Quercus suber, Quercus ilex, Quercus faginea, Pinus pinaster and Pinus pinea) in The Cardeña-Montoro Natural Park, a nature reserve that consists of a 38,449 ha forested area in southern Spain. Sixty-eight sampling points were selected in the study zone. Each sampling point was analyzed as soil control section with different depth increments (0-25, 25-50, 50-75 and 75-100 cm). The studied soils were classified as Cambisols and the major goal of this research was to study the SOCS variability at regional scale. The total SOCS in The Cardeña-Montoro Natural Park was higher in MEOW with olive grove (111,69 Mg ha-1) and lower in MEOW with Quercus faginea (93,57 Mg ha-1). However, when the top soil (superficial section control) was analyzed, the SOCS was the highest in MEOW with olive grove (70,12 Mg-1) and the lowest in MEOW with Pinus (47,82 Mg ha-1). This research is a preliminary assessment for modeling SOCS at the regional level in Mediterranean natural areas. References Hontoria, C., Rodríguez-Murillo, J., and Saa, A.: Contenido de carbono orgánico en el suelo y factores de control en la España Peninsular, Edafología, 11, 149-155, 2004. Parras-Alcántara, L., Díaz-Jaimes, L., and Lozano-García, B: Organic farming affects C and N in soils under olive groves in Mediterranean areas, Land Degrad. Develop., in press, available online: in Wiley Online Library (wileyonlinelibrary.com), http://dx.doi.org/10.1002/ldr.2231, 2013. Parras-Alcántara, L., Díaz-Jaimes, L., Lozano-García, B., Fernández Rebollo, P., Moreno Elcure, F., Carbonero Muñoz, M.D.: Organic farming has little effect on carbon stock in a Mediterranean dehesa (southern Spain). Catena 113 (2014) 9-17. http://dx.doi.org/10.1016/j.catena.2013.09.002 Parras-Alcántara, L., Díaz-Jaimes, L., and Lozano-García, B.: Management effects on soil organic carbon stock in Mediterranean open rangelands -- treeless grasslands, Land Degrad. Develop., in press, available online: in Wiley Online Library (wileyonlinelibrary.com), http://dx.doi.org/10.1002/ldr.2269, 2015.
18. Ecology.
Science.gov (United States)
National Audubon Society, New York, NY.
This set of teaching aids consists of nine Audubon Nature Bulletins, providing teachers and students with informational reading on various ecological topics. The bulletins have these titles: Schoolyard Laboratories, Owls and Predators, The Forest Community, Life in Freshwater Marshes, Camouflage in the Animal World, Life in the Desert, The…
19. Seasat synthetic aperture radar /SAR/ response to lowland vegetation types in eastern Maryland and Virginia
Science.gov (United States)
Krohn, M. D.; Milton, N. M.; Segal, D. B.
1983-01-01
Examination of Seasat SAR images of eastern Maryland and Virginia reveals botanical distinctions between vegetated lowland areas and adjacent upland areas. Radar returns from the lowland areas can be either brighter or darker than returns from the upland forests. Scattering models and scatterometer measurements predict an increase of 6 dB in backscatter from vegetation over standing water. This agrees with the 30-digital number (DN) increase observed in the digital Seasat data. The brightest areas in the Chickahominy, Virginia, drainage, containing P. virginica about 0.4 m high, contrast with the brightest areas in the Blackwater, Maryland, marshes, which contain mature loblolly pine in standing water. The darkest vegetated area in the Chickahominy drainage contains a forest of Nyssa aquatica (water tupelo) about 18 m high, while the darkest vegetated area in the Blackwater marshes contains the marsh plant Spartina alterniflora, 0.3 m high. The density, morphology, and relative geometry of the lowland vegetation with respect to standing water can all affect the strength of the return L band signal.
20. Ecological Impacts of the Cerro Grande Fire: Predicting Elk Movement and Distribution Patterns in Response to Vegetative Recovery through Simulation Modeling October 2005
Energy Technology Data Exchange (ETDEWEB)
S.P. Rupp
2005-10-01
In May 2000, the Cerro Grande Fire burned approximately 17,200 ha in north-central New Mexico as the result of an escaped prescribed burn initiated by Bandelier National Monument. The interaction of large-scale fires, vegetation, and elk is an important management issue, but few studies have addressed the ecological implications of vegetative succession and landscape heterogeneity on ungulate populations following large-scale disturbance events. Primary objectives of this research were to identify elk movement pathways on local and landscape scales, to determine environmental factors that influence elk movement, and to evaluate movement and distribution patterns in relation to spatial and temporal aspects of the Cerro Grande Fire. Data collection and assimilation reflect the collaborative efforts of National Park Service, U.S. Forest Service, and Department of Energy (Los Alamos National Laboratory) personnel. Geographic positioning system (GPS) collars were used to track 54 elk over a period of 3+ years and locational data were incorporated into a multi-layered geographic information system (GIS) for analysis. Preliminary tests of GPS collar accuracy indicated a strong effect of 2D fixes on position acquisition rates (PARs) depending on time of day and season of year. Slope, aspect, elevation, and land cover type affected dilution of precision (DOP) values for both 2D and 3D fixes, although significant relationships varied from positive to negative making it difficult to delineate the mechanism behind significant responses. Two-dimensional fixes accounted for 34% of all successfully acquired locations and may affect results in which those data were used. Overall position acquisition rate was 93.3% and mean DOP values were consistently in the range of 4.0 to 6.0 leading to the conclusion collar accuracy was acceptable for modeling purposes. SAVANNA, a spatially explicit, process-oriented ecosystem model, was used to simulate successional dynamics. Inputs to the SAVANNA included a land cover map, long-term weather data, soil maps, and a digital elevation model. Parameterization and calibration were conducted using field plots. Model predictions of herbaceous biomass production and weather were consistent with available data and spatial interpolations of snow were considered reasonable for this study. Dynamic outputs generated by SAVANNA were integrated with static variables, movement rules, and parameters developed for the individual-based model through the application of a habitat suitability index. Model validation indicated reasonable model fit when compared to an independent test set. The finished model was applied to 2 realistic management scenarios for the Jemez Mountains and management implications were discussed. Ongoing validation of the individual-based model presented in this dissertation provides an adaptive management tool that integrates interdisciplinary experience and scientific information, which allows users to make predictions about the impact of alternative management policies.
1. Fruit and vegetable intake and type 2 diabetes : EPIC-InterAct prospective study and meta-analysis
DEFF Research Database (Denmark)
Cooper, A J; Forouhi, N G
2012-01-01
Fruit and vegetable intake (FVI) may reduce the risk of type 2 diabetes (T2D), but the epidemiological evidence is inconclusive. The aim of this study is to examine the prospective association of FVI with T2D and conduct an updated meta-analysis. In the European Prospective Investigation into Cancer-InterAct (EPIC-InterAct) prospective case-cohort study nested within eight European countries, a representative sample of 16?154 participants and 12?403 incident cases of T2D were identified from 340?234 individuals with 3.99 million person-years of follow-up. For the meta-analysis we identified prospective studies on FVI and T2D risk by systematic searches of MEDLINE and EMBASE until April 2011. In EPIC-InterAct, estimated FVI by dietary questionnaires varied more than twofold between countries. In adjusted analyses the hazard ratio (95% confidence interval) comparing the highest with lowest quartile of reported intake was 0.90 (0.80-1.01) for FVI; 0.89 (0.76-1.04) for fruit and 0.94 (0.84-1.05) for vegetables. Among FV subtypes, only root vegetables were inversely associated with diabetes 0.87 (0.77-0.99). In meta-analysis using pooled data from five studies including EPIC-InterAct, comparing the highest with lowest category for FVI was associated with a lower relative risk of diabetes (0.93 (0.87-1.00)). Fruit or vegetables separately were not associated with diabetes. Among FV subtypes, only green leafy vegetable (GLV) intake (relative risk: 0.84 (0.74-0.94)) was inversely associated with diabetes. Subtypes of vegetables, such as root vegetables or GLVs may be beneficial for the prevention of diabetes, while total FVI may exert a weaker overall effect.European Journal of Clinical Nutrition advance online publication, 1 August 2012; doi:10.1038/ejcn.2012.85.
2. Identification of phenological stages and vegetative types for land use classification
Science.gov (United States)
Mckendrick, J. D. (principal investigator)
1973-01-01
The author had identified the following significant results. Digital signatures derived from the CDU are comparable to those taken from the printouts. Therefore, using the CDU to derive signatures should be more efficient, since there is considerable time required in turn around with the computer and time required locating vegetation stands on the printout.
3. Vegetation types of East Ladakh: species and growth form composition along main environmental gradients.
Czech Academy of Sciences Publication Activity Database
Dvorský, Miroslav; Doležal, Ji?í; de Bello, Francesco; Klimešová, Jitka; Klimeš, Leoš
2011-01-01
Ro?. 14, ?. 1 (2011), 132-147. ISSN 1402-2001 R&D Projects: GA AV ?R IAA600050802 Institutional research plan: CEZ:AV0Z60050516 Keywords : alpine vegetation * Classification * Trans-Himalaya Subject RIV: EF - Botanics Impact factor: 1.678, year: 2011
4. Preliminary estimation of bryophyte biomass and carbon pool from three contrasting different vegetation types.
Czech Academy of Sciences Publication Activity Database
Singh, M.K.; Juhász, A.; Csintalan, Z.; Kaligaric, M.; Marek, Michal V.; Urban, Otmar; Tuba, Z.
2005-01-01
Ro?. 33, ?. 1 (2005), s. 267-270. ISSN 0133-3720 Grant ostatní: EU(CZ) HPRI-CT-2002-00197 Institutional research plan: CEZ:AV0Z60870520 Keywords : bryophyte * carbon pool * rain forest Subject RIV: EH - Ecology, Behaviour Impact factor: 0.320, year: 2005
5. Plant seedlings in a species-rich meadow: effect of management, vegetation type and functional traits.
Czech Academy of Sciences Publication Activity Database
Mudrák, Ond?ej; Doležal, Ji?í; Hájek, M.; Dan?ák, M.; Klimeš, Leoš; Klimešová, Jitka
2013-01-01
Ro?. 16, ?. 2 (2013), s. 286-295. ISSN 1402-2001 R&D Projects: GA ?R GA526/09/0963 Institutional support: RVO:67985939 Keywords : Bile Karpaty Mountains * Litter * Mowing Subject RIV: EH - Ecology, Behaviour Impact factor: 2.416, year: 2013
6. Soil microfungi in two post-mining chronosequences with different vegetation types.
Czech Academy of Sciences Publication Activity Database
Nováková, Alena
2001-01-01
Ro?. 9, ?. 4 (2001), s. 351-358. ISSN 1061-2971 R&D Projects: GA MŠk ME 076 Institutional research plan: CEZ:AV0Z6066911 Keywords : soil microfungi * frequency of species occurrence * post-mining dumps Subject RIV: EH - Ecology, Behaviour Impact factor: 1.011, year: 2001
7. Variations in fresh fruit and vegetable quality by store type, urban-rural setting and neighbourhood deprivation in Scotland. — Measures of the Food Environment
Science.gov (United States)
Cummins S, Smith DM, Taylor M, Dawson J, Marshall D, Sparks L, Anderson AS. Variations in fresh fruit and vegetable quality by store type, urban-rural setting and neighbourhood deprivation in Scotland.
8. Physiological quality in seeds obtained by topcrosses between vegetable soybean and grain type
OpenAIRE
Gilberto K. Yokomizo; Natal A. Vello
2000-01-01
Attempts were made to study the gene introgression for high physiological quality from adapted cultivars in the vegetable soybean (exotic). Promising results were obtained for all topocrosses, with increased in germination percentage in majority. General mean of the germination percentage in topcrosses with large seeds exotic parental showed an increase from 28 to 46%, and topcrosses with small seeds exotic parental, from 54 up to 60%, both cases compared to self pollinated exotic parental. R...
9. Effect of non-crop vegetation types on conservation biological control of pests in olive groves
OpenAIRE
Daniel Paredes; Luis Cayuela; Gurr, Geoff M.; Mercedes Campos
2013-01-01
Conservation biological control (CBC) is an environmentally sound potential alternative to the use of chemical insecticides. It involves modifications of the environment to promote natural enemy activity on pests. Despite many CBC studies increasing abundance of natural enemies, there are far fewer demonstrations of reduced pest density and very little work has been conducted in olive crops. In this study we investigated the effects of four forms of non-crop vegetation on the abundance of two...
10. Spatial and temporal patterns of greenness on the Yamal Peninsula, Russia: interactions of ecological and social factors affecting the Arctic normalized difference vegetation index
International Nuclear Information System (INIS)
The causes of a greening trend detected in the Arctic using the normalized difference vegetation index (NDVI) are still poorly understood. Changes in NDVI are a result of multiple ecological and social factors that affect tundra net primary productivity. Here we use a 25 year time series of AVHRR-derived NDVI data (AVHRR: advanced very high resolution radiometer), climate analysis, a global geographic information database and ground-based studies to examine the spatial and temporal patterns of vegetation greenness on the Yamal Peninsula, Russia. We assess the effects of climate change, gas-field development, reindeer grazing and permafrost degradation. In contrast to the case for Arctic North America, there has not been a significant trend in summer temperature or NDVI, and much of the pattern of NDVI in this region is due to disturbances. There has been a 37% change in early-summer coastal sea-ice concentration, a 4% increase in summer land temperatures and a 7% change in the average time-integrated NDVI over the length of the satellite observations. Gas-field infrastructure is not currently extensive enough to affect regional NDVI patterns. The effect of reindeer is difficult to quantitatively assess because of the lack of control areas where reindeer are excluded. Many of the greenest landscapes on the Yamal are associated with landslides and drainage networks that have resulted from ongoing rapid permafrost degradation. A warming climate and enhanced winter snow awarming climate and enhanced winter snow are likely to exacerbate positive feedbacks between climate and permafrost thawing. We present a diagram that summarizes the social and ecological factors that influence Arctic NDVI. The NDVI should be viewed as a powerful monitoring tool that integrates the cumulative effect of a multitude of factors affecting Arctic land-cover change.
11. Eddy covariance and scintillation measurements of atmospheric exchange processes over different types of vegetation
OpenAIRE
Nieveen, J.P.
1999-01-01
Introduction and objectivesGood comprehension of the energy and mass cycles and their effect on climate dynamics is crucial to understanding, predicting and anticipating ecological changes due to possible future climate perturbations. Here direct and long-term flux density measurements of greenhouse gases from various ecosystems provide means to supply such fundamental knowledge. For the global water vapour and carbon cycles, however, the interactions between different spatial scales become i...
12. The influence of slope and peatland vegetation type on riverine dissolved organic carbon and water colour at different scales.
Science.gov (United States)
Parry, L E; Chapman, P J; Palmer, S M; Wallage, Z E; Wynne, H; Holden, J
2015-09-15
Peatlands are important sources of fluvial carbon. Previous research has shown that riverine dissolved organic carbon (DOC) concentrations are largely controlled by soil type. However, there has been little work to establish the controls of riverine DOC within blanket peatlands that have not undergone major disturbance from drainage or burning. A total of 119 peatland catchments were sampled for riverine DOC and water colour across three drainage basins during six repeated sampling campaigns. The topographic characteristics of each catchment were determined from digital elevation models. The dominant vegetation cover was mapped using 0.5m resolution colour infrared aerial images, with ground-truthed validation revealing 82% accuracy. Forward and backward stepwise regression modelling showed that mean slope was a strong (and negative) determinant of DOC and water colour in blanket peatland river waters. There was a weak role for plant functional type in determining DOC and water colour. At the basin scale, there were major differences between the models depending on the basin. The dominance of topographic predictors of DOC found in our study, combined with a weaker role of vegetation type, paves the way for developing improved planning tools for water companies operating in peatland catchments. Using topographic data and aerial imagery it will be possible to predict which tributaries will typically yield lower DOC concentrations and which are therefore more suitable and cost-effective as raw water intakes. PMID:26003614
13. Landscape object-based analysis of wetland plant functional types: the effects of spatial scale, vegetation classes and classifier methods
Science.gov (United States)
Dronova, I.; Gong, P.; Wang, L.; Clinton, N.; Fu, W.; Qi, S.
2011-12-01
Remote sensing-based vegetation classifications representing plant function such as photosynthesis and productivity are challenging in wetlands with complex cover and difficult field access. Recent advances in object-based image analysis (OBIA) and machine-learning algorithms offer new classification tools; however, few comparisons of different algorithms and spatial scales have been discussed to date. We applied OBIA to delineate wetland plant functional types (PFTs) for Poyang Lake, the largest freshwater lake in China and Ramsar wetland conservation site, from 30-m Landsat TM scene at the peak of spring growing season. We targeted major PFTs (C3 grasses, C3 forbs and different types of C4 grasses and aquatic vegetation) that are both key players in system's biogeochemical cycles and critical providers of waterbird habitat. Classification results were compared among: a) several object segmentation scales (with average object sizes 900-9000 m2); b) several families of statistical classifiers (including Bayesian, Logistic, Neural Network, Decision Trees and Support Vector Machines) and c) two hierarchical levels of vegetation classification, a generalized 3-class set and more detailed 6-class set. We found that classification benefited from object-based approach which allowed including object shape, texture and context descriptors in classification. While a number of classifiers achieved high accuracy at the finest pixel-equivalent segmentation scale, the highest accuracies and best agreement among algorithms occurred at coarser object scales. No single classifier was consistently superior across all scales, although selected algorithms of Neural Network, Logistic and K-Nearest Neighbors families frequently provided the best discrimination of classes at different scales. The choice of vegetation categories also affected classification accuracy. The 6-class set allowed for higher individual class accuracies but lower overall accuracies than the 3-class set because individual classes differed in scales at which they were best discriminated from others. Main classification challenges included a) presence of C3 grasses in C4-grass areas, particularly following harvesting of C4 reeds and b) mixtures of emergent, floating and submerged aquatic plants at sub-object and sub-pixel scales. We conclude that OBIA with advanced statistical classifiers offers useful instruments for landscape vegetation analyses, and that spatial scale considerations are critical in mapping PFTs, while multi-scale comparisons can be used to guide class selection. Future work will further apply fuzzy classification and field-collected spectral data for PFT analysis and compare results with MODIS PFT products.
14. The effect of vegetation type and fire on permafrost thaw: An empirical test of a process based model
Science.gov (United States)
Thierry, Aaron; Estop-Aragones, Cristian; Fisher, James; Hartley, Iain; Murton, Julian; Phoenix, Gareth; Street, Lorna; Williams, Mathew
2015-04-01
As conditions become more favourable for plant growth in the high latitudes, most models predict that these areas will take up more carbon during the 21st century. However, vast stores of carbon are frozen in boreal and arctic permafrost, and warming may result in some of this carbon being released to the atmosphere. The recent inclusion of permafrost thaw in large-scale model simulations has suggested that the permafrost feedback could potentially substantially reduce the predicted global net uptake of carbon by terrestrial ecosystems, with major implications for the rate of climate change. However, large uncertainties remain in predicting rates of permafrost thaw and in determining the impacts of thaw in contrasting ecosystems, with many of the key processes missing from carbon-climate models. The role that different plant communities play in insulating soils and protecting permafrost is poorly quantified, with key groups such as mosses absent in many models. But it is thought that they may play a key role in determining permafrost resilience. In order to test the importance of these ecological processes we use a new specially acquired dataset from sites in the Canadian arctic to develop, parameterise and evaluate a detailed process-based model of vegetation-soil-permafrost interactions which includes an insulating moss understory. We tested the sensitivity of modelled active layer depth to a series of factors linked to fire disturbance, which is common in boreal permafrost areas. We show how simulations of active layer depth (ALD) respond to removals of (i) vascular vegetation, (ii) moss cover, and (iii) organic soil layers. We compare model responses to observed patterns from Canada. We also describe the sensitivity of our modelled ALD to changes in temperature and precipitation. We found that four parameters controlled most of the sensitivity in the modelled ALD, linked to conductivity of organic soils and mosses.
15. Influência do tipo da cobertura vegetal sobre a erosão no semi-árido Paraibano / Influence of the type of vegetal cover on sediment yield in the semiarid of Paraíba state
Scientific Electronic Library Online (English)
Celso Augusto Guimarães, Santos; Koichi, Suzuki; Masahiro, Watanabe; Vajapeyam S., Srinivasan.
2000-04-01
Full Text Available O tipo de cobertura vegetal, presente numa área, tem grande influência sobre o escoamento superficial e a produção de sedimentos. O objetivo do presente trabalho é estabelecer uma relação entre o tipo da cobertura vegetal e a erosão do solo nu, mediante uma equação empírica da perda de solo. A equaç [...] ão proposta foi calibrada usando-se dados sintéticos gerados por um modelo físico hidrossedimentológico, cujos parâmetros de erosão foram determinados como valores representativos de uma área desmatada do semi-árido paraibano. Apresenta-se uma comparação entre os valores calculados pela equação e os dados observados em várias parcelas de erosão, as quais apresentavam condições de cobertura vegetal e declividade distintas, localizadas na Bacia Experimental de Sumé, PB. Esta comparação permitiu uma avaliação da influência do tipo de cobertura vegetal sobre a erosão do solo. Abstract in english The type of vegetation cover present in an area, greatly influences the surface runoff as well as the sediment yield. The objective of this paper is to establish a relationship between the type of vegetal cover and erosion by means of an empirical equation for soil loss. The proposed equation was ca [...] librated using synthetic data obtained from a physically-based runoff-erosion model in which the erosion parameter values are representative of a cleared bare-land surface in the semiarid area of Paraíba State. A comparison between the values obtained from the equation and the observed data collected from several erosion plots in the Sumé Experimental Watershed with different conditions of vegetal cover and slope is presented as an evaluation of the influence of the vegetation cover on soil erosion.
16. Avaliação nutricional da glicerina vegetal semipurificada para codornas de corte / Nutritional evaluation of vegetable semi-purified glycerin of meat type quail
Scientific Electronic Library Online (English)
E., Batista; A.C., Furlan; A.P.S., Ton; T.J., Pasquetti; T.C.O., Quadros; D.O., Grieser; V., Zancanela.
2013-12-01
17. A new quantitative classification of ecological types in the bromeliad genus Tillandsia (Bromeliaceae based on trichomes
Directory of Open Access Journals (Sweden)
Mosti Stefano
2008-03-01
Full Text Available Using collection specimens, we measured the density and wing area of trichomes in 37 species of the bromeliad genus Tillandsia, specifically the abaxial proximal, abaxial distal, adaxial proximal and adaxial distal parts of the leaf. The product of the trichome "wing" area by the number of trichomes (means produced a pure number (T that was correlated to ecological features. The correlation was positive with respect to arid environments (xeric Tillands and negative with respect to humid environments (mesic Tillands. Bulbous, and particularly myrmecophytic species and species with tanks, represented particular categories. Other intermediate types were identified based on the T number, totalling five ecological types. In comparison with other systems of ecological typification for Tillands and other Bromeliaceae, the present system offers measurable data whose analysis is reproducible. Rev. Biol. Trop. 56 (1: 191-203. Epub 2008 March 31.Medimos el número por milímetro cuadrado y el área del "ala" (parte móvil de los tricomas en las partes adaxial próxima y distal, y adaxial próxima y distal, de la hoja de 37 especies de bromelias del género Tillandsia. El producto del área del ala para el número de los tricomas (promedio produjo un número puro (T. Hallamos que T se correlaciona con las características ecológicas de las tilandsias investigadas. La correlación es positiva con respecto a ambientes áridos (especies xéricas y negativa con respecto a los ambientes húmedos (especies mésicas. Las especies con bulbo, y particularmente las asociadas con hormigas y especies con de tanque representan categorías particulares. Identificamos otros tipos intermedios, agradando así cinco tipos ecológicos. En comparación con otros sistemas de tipificación ecológica, este sistema ofrece la ventaja de ser reproducible y cuantitativo.
18. A new quantitative classification of ecological types in the bromeliad genus Tillandsia (Bromeliaceae) based on trichomes
Scientific Electronic Library Online (English)
Mosti, Stefano; Alessio, Papini; Luigi, Brighigna.
2008-03-01
Full Text Available Medimos el número por milímetro cuadrado y el área del "ala" (parte móvil) de los tricomas en las partes adaxial próxima y distal, y adaxial próxima y distal, de la hoja de 37 especies de bromelias del género Tillandsia. El producto del área del ala para el número de los tricomas (promedio) produjo [...] un número puro (T). Hallamos que T se correlaciona con las características ecológicas de las tilandsias investigadas. La correlación es positiva con respecto a ambientes áridos (especies xéricas) y negativa con respecto a los ambientes húmedos (especies mésicas). Las especies con bulbo, y particularmente las asociadas con hormigas y especies con de tanque representan categorías particulares. Identificamos otros tipos intermedios, agradando así cinco tipos ecológicos. En comparación con otros sistemas de tipificación ecológica, este sistema ofrece la ventaja de ser reproducible y cuantitativo. Abstract in english Using collection specimens, we measured the density and wing area of trichomes in 37 species of the bromeliad genus Tillandsia, specifically the abaxial proximal, abaxial distal, adaxial proximal and adaxial distal parts of the leaf. The product of the trichome "wing" area by the number of trichomes [...] (means) produced a pure number (T) that was correlated to ecological features. The correlation was positive with respect to arid environments (xeric Tillands) and negative with respect to humid environments (mesic Tillands). Bulbous, and particularly myrmecophytic species and species with tanks, represented particular categories. Other intermediate types were identified based on the T number, totalling five ecological types. In comparison with other systems of ecological typification for Tillands and other Bromeliaceae, the present system offers measurable data whose analysis is reproducible. Rev. Biol. Trop. 56 (1): 191-203. Epub 2008 March 31.
19. An expert system shell for inferring vegetation characteristics: Changes to the historical cover type database (Task F)
Science.gov (United States)
1993-01-01
All the options in the NASA VEGetation Workbench (VEG) make use of a database of historical cover types. This database contains results from experiments by scientists on a wide variety of different cover types. The learning system uses the database to provide positive and negative training examples of classes that enable it to learn distinguishing features between classes of vegetation. All the other VEG options use the database to estimate the error bounds involved in the results obtained when various analysis techniques are applied to the sample of cover type data that is being studied. In the previous version of VEG, the historical cover type database was stored as part of the VEG knowledge base. This database was removed from the knowledge base. It is now stored as a series of flat files that are external to VEG. An interface between VEG and these files was provided. The interface allows the user to select which files of historical data to use. The files are then read, and the data are stored in Knowledge Engineering Environment (KEE) units using the same organization of units as in the previous version of VEG. The interface also allows the user to delete some or all of the historical database units from VEG and load new historical data from a file. This report summarizes the use of the historical cover type database in VEG. It then describes the new interface to the files containing the historical data. It describes minor changes that were made to VEG to enable the externally stored database to be used. Test runs to test the operation of the new interface and also to test the operation of VEG using historical data loaded from external files are described. Task F was completed. A Sun cartridge tape containing the KEE and Common Lisp code for the new interface and the modified version of the VEG knowledge base was delivered to the NASA GSFC technical representative.
20. Tidal Creek Morphology and Sediment Type Influence Spatial Trends in Salt Marsh Vegetation
DEFF Research Database (Denmark)
Kim, Daehyun; Cairns, David M.
2013-01-01
Zonal patterns of salt marsh plants and physical conditions have been addressed primarily across the elevation gradient from inland to coastline rather than across tidal creeks in relation to their hydro-geomorphic processes such as bar formation and bank erosion. We found at a Danish marsh that by shaping major geomorphic features and providing sediments to the adjacent sites, fluvial-geomorphic processes of tidal creeks exert fundamental controls on the cross-channel distribution of abiotic and biotic factors. These results point to a need for biogeomorphic and landscape ecological perspectives to fully understand the underlying structure and geographic variability in salt marshes.
1. Behavior of the vegetable crops section in three types of food retail stores in Campo Grande, Brazil Desempenho da seção de hortaliças em equipamentos varejistas de alimentos
OpenAIRE
Dario de O Lima-Filho; Anderson S Hokama; Caroline P Spanhol
2009-01-01
The behavior of the fresh fruits and vegetable produce section was evaluated, under the point of view of the consumer, in three types of food retail stores in Campo Grande, Brazilian southeast: a grocery store ("quitanda"), a supermarket, and an open-air market. A quantitative-descriptive survey was conducted with 120 individuals, responsible for purchasing fresh fruit and vegetable produce for their homes. To accomplish that, twelve variables were investigated and adapted from the parameters...
2. Residues and potential ecological risks of veterinary antibiotics in manures and composts associated with protected vegetable farming.
Science.gov (United States)
Zhang, Haibo; Luo, Yongming; Wu, Longhua; Huang, Yujuan; Christie, Peter
2015-04-01
Veterinary antibiotics (VAs) are emerging contaminants and enter into soil principally by agricultural application of organic fertilizer. A total of 33 solid animal manures and 17 compost samples from protected vegetable farms in nine areas of China were analyzed for the antibiotic classes of tetracyclines, fluoroquinolones, sulfonamides, and macrolides (17 substances in total). Oxytetracycline was found as a dominant compound in the samples, and its highest concentration reached 416.8 mg kg(-1) in a chicken manure sample from Shouguang, Shandong Province. Among the samples, animal manures (especially pig manure) contained higher VA residues than composts. However, fluoroquinolones exhibited higher persistence in the compost samples than other antibiotic classes. This is particularly the case in the rice husk compost, which contained the highest level of ofloxacin and ciprofloxacin (1334.5 and 1717.4 ?g kg(-1) on average, respectively). The veterinary antibiotic profile in the risk husk compost had a good relationship with that in the corresponding manures. The refined commercial compost had the lowest VA residues among the compost samples in general. This implied that composting process might be important to reduce the antibiotic residue. High residue of antibiotics in soil was assumed to be a hazard to ecosystem. This is especially noticeable under current application rates (150 t ha(-1) a(-1)) in protected vegetable farming because over half of the samples exhibited a risk quotient (RQ) >1 for one or more antibiotics. PMID:25354434
3. Série temporal de índice de vegetação sobre diferentes tipologias vegetais no Rio Grande do Sul / Time series of vegetation index for different vegetation types in Rio Grande do Sul
Scientific Electronic Library Online (English)
Tatiana M., Kuplich; Andreise, Moreira; Denise C., Fontana.
2013-10-01
Full Text Available Com este trabalho objetivou-se identificar a dinâmica fenológica das principais tipologias vegetais do Rio Grande do Sul, para o período de 2000 a 2010, utilizando-se dados de Enhanced Vegetation Index, através da transformada de ondaleta. A identificação da fenologia em ciclos ou padrões sazonais e [...] m séries temporais de índices de vegetação, obtidos por sensores orbitais, permite a observação de anomalias e os efeitos de mudanças climáticas ou ambientais. Um perfil temporal do Enhanced Vegetation Index foi construído para o Rio Grande do Sul e retiradas amostras para quatro tipologias vegetais: campo nativo, floresta ombrófila mista, cultivo de soja e de arroz. Essas amostras foram submetidas à transformada de ondaleta, que permitiu a decomposição da série e apresentação dos dados em relação ao tempo e frequência com que os eventos fenológicos ocorreram. Os dados apresentaram regularidade na dinâmica das tipologias vegetais testadas, com ciclos anuais de maior vigor e crescimento vegetal nas estações de primavera e verão e menor no outono e inverno. Abstract in english The objective of this study was the identification of the phenology dynamics of the main types of vegetation of Rio Grande do Sul state, for the period from 2000 to 2010, using Enhanced Vegetation Index data through the wavelet transform. The identification of cycles or seasonal patterns in time ser [...] ies of vegetation indices obtained by orbital sensors allows the observation of anomalies and effects of climate and environmental change. A temporal profile of Enhanced Vegetation Index was built for the Rio Grande do Sul region, where samples of the four main plant typologies were selected: native grassland, mixed ombrophilous forest, soybean and rice crop. These samples were submitted to the wavelet transform, which allowed the decomposition of the series and presentation of data in relation to time and frequency with which the phenological events have occurred. The data showed regularity in the dynamics of vegetation types tested, with annual cycles of plant growth and higher Enhanced Vegetation Index values in spring and summer and lower Enhanced Vegetation Index values in autumn and winter.
4. Assessment of Trace Gas Emissions From Wild Fires in Different Vegetation Types in Northern Ghana: Implications for Global Warming
Directory of Open Access Journals (Sweden)
2015-03-01
Full Text Available Biomass burning in Northern Ghana is a major cause for concern because of its potential contribution to global warming, hence climate change. This study assessed the emission of trace gases from human activities in the Guinea savanna of Northern Ghana using the guidelines of the Intergovernmental Panel on Climate Change. Carbon content of biomass was determined from four different vegetation covers in the study area; namely, widely open savanna woodland, grass/herb with scattered trees, open savanna woodland and closed savanna woodland. Under each vegetation cover, five plots (1 m x 1 m were demarcated for the estimation of above-ground biomass density. Using the combustion furnace method, emitted carbon, methane and carbon monoxide were estimated. Results showed that the emitted methane (CH4 and carbon monoxide (CO differed significantly (p<0.05 under all the vegetation types. The gases were in perfect correlation (r=1.00 with the quantity of above-ground biomass density and carbon released, with more CO being emitted. Emission of CH4 and CO per hectare of burnt area in the open savanna woodland category was the highest with 0.001719 ton and 0.045119 ton respectively. Over time, emission of these gases may increase their atmospheric concentration, causing major health problems. The contribution to global warming, thus climate change, may also become quite significant. This underscores the fact that existing flaws in the wild fire management policy of Ghana must be effectively dealt with and appropriately implemented with regular reviews to reduce the annual wild fires that are very rampant in Northern Ghana, especially during the dry season.
5. Feed intake and activity level of two broiler genotypes foraging different types of vegetation in the finishing period
DEFF Research Database (Denmark)
Almeida, Gustavo Fonseca; Hinrichsen, Lena Karina
2012-01-01
A study was performed with 2 broiler genotypes (slow and medium growth) restricted in supplementary feed and foraging 2 different mixed vegetations (grass/clover or chicory) to identify possible benefits of herbage on nutrition during the finishing period (80 to 113 d of age). Three hundred birds were included in a 2 × 2 factorial design with groups of 25 birds replicated 3 times. The use of outdoor areas, performance, and forage intake were investigated. To identify possible differences in foraging activity, the use of the range was monitored one day per week at 4 different times of the day. Feed intake from foraging was estimated by killing 4 birds per plot (2 males and 2 females) in the morning and in the evening on 3 d during the experiment and measuring crop content. Vegetation type did not influence broiler use of the free-range area, feed intake, or performance. Differences in the use of the range area, activity level, and feed content in the crops were observed in relation to genotype, sex, age of broilers, and also the time of day. Foraging activity was positively correlated with age. Medium-growth broilers spent more time inside and closer to the broiler houses during the day with increased foraging activity during evenings, in contrast to the slow-growing broilers that showed a more uniform activity during the day. Based on the measurement of crop content it was estimated that the slow-growing genotype had a daily intake of 5 to 8 g of forage per day, whereas the medium-growing genotype had an intake of 9 g for females and 20 g for males. In conclusion, limitation of supplemented protein feed in the finishing period may be acceptable for broilers that have access to highly nutritious vegetation.
6. Vegetables and PUFA-rich plant oil reduce DNA strand breaks in individuals with type 2 diabetes
DEFF Research Database (Denmark)
Müllner, Elisabeth; Brath, Helmut
2013-01-01
SCOPE: Type 2 diabetes is a multifactorial disease associated with increased oxidative stress, which may lead to increased DNA damage. The aim of this study was to investigate the effect of a healthy diet on DNA oxidation in diabetics and nondiabetics. METHODS AND RESULTS: Seventy-six diabetic and 21 nondiabetic individuals participated in this study. All subjects received information about the benefits of a healthy diet, while subjects randomly assigned to the intervention group received additionally 300 g of vegetables and 25 mL PUFA-rich plant oil per day. DNA damage in mononuclear cells (Comet Assay), urinary excretion of 8-oxo-7-hydro-2'-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoGuo) and glycated hemoglobin (HbA1c) were measured at baseline, after 4, 8 (end of intervention), and 16 weeks. The intervention with vegetables and PUFA-rich oil led to a significant increase in plasma antioxidant concentrations. Diabetic individuals of the intervention group showed a significant reduction inHbA1c and DNA strand breaks. Levels of HbA1c were also improved in diabetics of the information group, but oxidative damage to DNA was not altered. Urinary 8-oxodG and 8-oxoGuo excretion remained unchanged in both groups. CONCLUSIONS: This study provides evidence that a healthy diet rich in antioxidants reduces levels of DNA strand breaks in diabetic individuals.
7. Characterisation of pastures in a eastern Alpine area in relation to ecological and management parameters
Directory of Open Access Journals (Sweden)
Sabatini S
2008-03-01
Full Text Available The present investigation was carried out in Val Visdende (north-eastern Italian Alps on a surface of 1108 ha, with the aim of identifying the most important pasture vegetation types. Based on the conditions observed in the area, main parameters concerning topographic, ecological and management conditions were evaluated and expressed using synthetic indexes. Cluster and principal component analyses were used for the interpretation of the distribution of pasture types in relation to ecological factors, allowing to formulate hypotheses on the evolution of pasture vegetation as a function of ecological and management parameters.
8. Physiological quality in seeds obtained by topcrosses between vegetable soybean and grain type
Directory of Open Access Journals (Sweden)
Gilberto K. Yokomizo
2000-01-01
9. Short-term trends in vegetation cover of Danish semi-natural ecosystems : a landscape-ecological assessment of main drivers indicated by traits of winner and loser species
DEFF Research Database (Denmark)
Timmermann, Allan; Damgaard, Christian
The landscapes in which many plant communities persist today are increasingly modified by anthropogenic activities, especially in Denmark, where most communities are influenced by for example atmospheric deposition of Nitrogen, changes in soil moisture levels (e.g. ground water-table changes caused by drainage) and changes in management regimes (primarily reduced grazing-pressure). Such modifications of the environment are filtering the persistence of species into those that are adapted to these new conditions (winners) and those that are not (losers). Across the landscape, it is reasonable to expect species with similar traits to respond similarly to systematic shifts in habitat conditions and disturbance. Consequently, contrasting traits of winner and loser species could be a powerful tool in identifying mechanisms that might be driving community changes. In this study, we use a large dataset of vegetation surveys from 207 semi-natural non-forested sites in Denmark, identifying temporal short-term changes in vegetation cover, notably identifying those species that are winners and losers. A further goal is to identify environmental drivers of contemporary vegetation change in Danish semi-natural habitats by quantifying which functional traits makes species decline or increase. We therefore assess whether winners and losers differ with regard to key functional traits and ecological indicator values, and whether these results match our expectations given the current anthropogenic disturbance regime. Notably, do winner and loser species display distinct sets of traits of the ones related to: exotic species invasion, eutrophication by nitrogen deposition, management changes (decreasing grazing and associated encroachment by woody plants), soil moisture changes (due to excessive water extraction and drainage)? Preliminary results suggest that even during a relative short time span of just seven years, it is possible to identify winner and loser species, indicating that significant shifts in species compositionare currently taking place in Danish semi-natural ecosystems. The number of identified loser species was greater than the number of identified winner species, suggesting that homogenization of species composition across the landscape may be a concern. Today, management of semi-natural habitats is a common conservation measure. However, despite traditional management, habitats may still be vulnerable to compositional changes due to e.g. surrounding land-use and atmospheric nitrogen deposition. The preliminary results from this study, are dichotomous in that it seems some factors as for example soil moisture and woody species encroachment are being managed in a way that opposites expectations from human disturbances, whereas management can not combat the effects of nitrogen deposition. Further analyses are still being developed to differentiate the landscape pattern of winners and losers into the specific habitat-types to induce differences between them in their responses to environmental drivers.
10. Vegetation associated with the occurrence of the Brenton blue butterfly
Scientific Electronic Library Online (English)
D.A., Edge; S.S., Cilliers; R.F., Terblanche.
2008-12-01
Full Text Available The Brenton blue butterfly, Orachrysops niobe (Trimen), is critically endangered and known only from one site near Knysna in the Western Cape province of South Africa, now proclaimed as the Brenton Blue Butterfly Reserve (BBBR). We have explored associations between vegetation types and the presence [...] of O. niobe's only host plant, Indigofera erecta (Thunb.), using Braun-Blanquet vegetation classification and ordination techniques as part of a broader research project at the BBBR. Positive correlations are demonstrated between the occurrence of I. erecta and certain thicket vegetation types dominated by Pterocelastrus tricuspidatus (candlewood trees). Ordinations using soil analysis and slope data have not detected significant environmental gradients influencing vegetation types. The high degree of vegetation heterogeneity at the BBBR appears to be driven in part by various disturbance histories. Historical ecological events at the site such as fire and megaherbivore impacts, and their role in sustaining the ideal habitat for I. erecta and O. niobe, are discussed. Management techniques for the BBBR such as controlled fires or the cutting of paths through the vegetation are evaluated and an optimum future management strategy is recommended. This is the most comprehensive vegetation study ever carried out at the habitat of an endangered butterfly in South Africa, and breaks new ground by using vegetation analysis to develop a well-informed management plan for conservation of this species. It has significance for the management of small sites where many such endangered butterflies occur.
11. Distribution of phytoplankton functional types in high-nitrate, low-chlorophyll waters in a new diagnostic ecological indicator model
Directory of Open Access Journals (Sweden)
A. P. Palacz
2013-11-01
Full Text Available Modeling and monitoring plankton functional types (PFTs is challenged by the insufficient amount of field measurements of ground truths in both plankton models and bio-optical algorithms. In this study, we combine remote sensing data and a dynamic plankton model to simulate an ecologically sound spatial and temporal distribution of phyto-PFTs. We apply an innovative ecological indicator approach to modeling PFTs and focus on resolving the question of diatom–coccolithophore coexistence in the subpolar high-nitrate and low-chlorophyll regions. We choose an artificial neural network as our modeling framework because it has the potential to interpret complex nonlinear interactions governing complex adaptive systems, of which marine ecosystems are a prime example. Using ecological indicators that fulfill the criteria of measurability, sensitivity and specificity, we demonstrate that our diagnostic model correctly interprets some basic ecological rules similar to ones emerging from dynamic models. Our time series highlight a dynamic phyto-PFT community composition in all high-latitude areas and indicate seasonal coexistence of diatoms and coccolithophores. This observation, though consistent with in situ and remote sensing measurements, has so far not been captured by state-of-the-art dynamic models, which struggle to resolve this "paradox of the plankton". We conclude that an ecological indicator approach is useful for ecological modeling of phytoplankton and potentially higher trophic levels. Finally, we speculate that it could serve as a powerful tool in advancing ecosystem-based management of marine resources.
12. Distribution of phytoplankton functional types in high-nitrate low-chlorophyll waters in a new diagnostic ecological indicator model
DEFF Research Database (Denmark)
Palacz, Artur; St. John, Michael
2013-01-01
Modeling and monitoring plankton functional types (PFTs) is challenged by insufficient amount of field measurements to ground-truth both plankton models and bio-optical algorithms. In this study, we combine remote sensing data and a dynamic plankton model to simulate an ecologically-sound spatial and temporal distribution of phyto-PFTs. We apply an innovative ecological indicator approach to modeling PFTs, and focus on resolving the question of diatom-coccolithophore co-existence in the subpolar high-nitrate and low-chlorophyll regions. We choose an artificial neural network as our modeling framework because it has the potential to interpret complex nonlinear interactions governing complex adaptive systems, of which marine ecosystems are a prime example. Using ecological indicators that fulfill the criteria of measurability, sensitivity and specificity, we demonstrate that our diagnostic model correctly interprets some basic ecological rules similar to ones emerging from dynamic models. Our time series highlight a dynamic phyto-PFT community composition in all high latitude areas, and indicate seasonal co-existence of diatoms and coccolithophores. This observation, though consistent with in situ and remote sensing measurements, was so far not captured by state-of-the-art dynamic models which struggle to resolve this "paradox of the plankton". We conclude that an ecological indicator approach is useful for ecological modeling of phytoplankton and potentially higher trophic levels. Finally, we speculate that it could serve as a powerful tool in advancing ecosystem-based management of marine resources
13. El uso del método de puntos de intercepción para cuantificar los tipos de vegetación y hábitats abióticos en los bofedales altoandinos / Using line-intercept methods to quantify vegetation types and abiotic habitats in high Andean wetlands
Scientific Electronic Library Online (English)
Kazuya, Naoki; Rosa Isela, Meneses; M. Isabel, Gómez; Carlos Miguel, Landivar.
2014-12-01
Full Text Available Los bofedales son ecosistemas húmedos altoandinos de los Andes centrales con una importancia socioeconómica y ecológica crucial en la región. El objetivo de nuestro estudio es describir el método de puntos de intercepción para cuantificar la disponibilidad y la variabilidad de las asociaciones veget [...] ales, así que la cobertura no vegetativa en los bofedales, datos útiles para categorizarlos. En el contexto de nuestro proyecto, tomado en cuenta como ejemplo, se aplicó el método en 40 bofedales ubicados en la Cordillera Real (Bolivia) donde se establecieron aleatoriamente 10-20 líneas de intercepción de 50 m en cada bofedal. En cada línea de intercepción se registró la cobertura a intervalos de 1 m y se registraron 22 categorías de coberturas reconocibles a simple vista. Discutimos la relevancia del método para realizar evaluaciones rápidas en diferentes estudios en bofedales. Al estar enfocado en tipos de vegetación en lugar de las especies vegetales, permite su aplicación por investigadores que no tienen un conocimiento taxonómico profundo de la flora local. Abstract in english Bofedales are high Andean wetlands found in the central Andes, which provide crucial socio-economic and ecological resources in this region. The aim of our study is to describe the line-intercept methods to quantify the availability and variability of plant association and non-vegetative cover in hi [...] gh Andean bogs. Within the project BIOTHAW, taken as a methodological example, the method was applied in 40 bogs located in the Cordillera Real (Bolivia). In each bofedal, between 10 and 20 50-m intercept lines were randomly established. Along each intercept line, one of the 22 coverage types recognizable to the naked eye was recorded at 1-m interval. We discuss the relevance of this method for rapid assessments in different studies on highland bogs. Since the method focuses on simple vegetation types rather than on plant species, it can be used by researchers who do not have a deep taxonomic knowledge of the local flora.
14. Major vegetation types of the Soutpansberg Conservancy and the Blouberg Nature Reserve, South Africa
OpenAIRE
Rachel E. Mostert; Cornie Verwey; Hannes L. Klopper; Bredenkamp, George J.; Theo H.C. Mostert; Norbert Hahn
2008-01-01
The Major Megetation Types (MVT) and plant communities of the Soutpansberg Centre of Endemism are described in detail, with special reference to the Soutpansberg Conservancy and the Blouberg Nature Reserve. Phytosociological data from 442 sample plots were ordinated using a DEtrended CORrespondence ANAlysis (DECORANA) and classified using TWo-Way INdicator SPecies ANalysis (TWINSPAN). The resulting classification was further refined with table-sorting procedures based on the Braun–Blanquet fl...
15. Late Holocene vegetation dynamics and deforestation in Rano Aroi: Implications for Easter Island's ecological and cultural history
Science.gov (United States)
Rull, Valentí; Cañellas-Boltà, Núria; Margalef, Olga; Sáez, Alberto; Pla-Rabes, Sergi; Giralt, Santiago
2015-10-01
Easter Island (Rapa Nui) has been considered an example of how societies can cause their own destruction through the overexploitation of natural resources. The flagship of this ecocidal paradigm is the supposed abrupt, island-wide deforestation that occurred about one millennium ago, a few centuries after the arrival of Polynesian settlers to the island. Other hypotheses attribute the forest demise to different causes such as fruit consumption by rats or aridity but the occurrence of an abrupt, island-wide deforestation during the last millennium has become paradigmatic in Rapa Nui. We argue that such a view can be questioned, as it is based on the palynological study of incomplete records, owing to the existence of major sedimentary gaps. Here, we present a multiproxy (pollen, charcoal and geochemistry) study of the Aroi core, the first gap-free sedimentary sequence of the last millennia obtained to date in the island. Our results show changing vegetation patterns under the action of either climatic or anthropogenic drivers, or both, depending on the time interval considered. Palm forests were present in Aroi until the 16th century, when deforestation started, coinciding with fire exacerbation -likely of human origin- and a dry climate. This is the latest deforestation event recorded so far in the island and took place roughly a century before European contact. In comparison to other Easter Island records, this record shows that deforestation was neither simultaneous nor proceeded at the same pace over the whole island. These findings suggest that Easter Island's deforestation was a heterogeneous process in space and time, and highlights the relevance of local catchment traits in the island's environmental and land management history.
16. Nitrogen–use efficiency in different vegetation type at Cikaniki Research Station, Halimun-Salak Mountain National Park, West Java
Directory of Open Access Journals (Sweden)
SUHARNO
2007-10-01
Full Text Available A research about nitrogen–use efficiency (NUE and trees identification was conducted at different vegetation type at Cikaniki, Halimun-Salak National Park, West Java. Plot quadrate methods (20 x 50 m was used to analyze trees vegetation and Kjeldahl methods was used to analyze leaf nitrogen. The width and length of the leaf was also measured to obtain the leaf surface area. The result showed that there are 61 individual trees which consisted of 24 species was identified. The species which have 5 highest important value are Altingia excelsa (64,657, Castanopsis javanica (39,698, Platea latifolia (27,684, Garcinia rostrata (21,151, and Schima walichii (16,049. Futhermore Eugenia lineata (13,967, Melanochyla caesa (12,241, Quercus lineata (10,766, platea excelsa (10,766 have lower important value. Other trees have important value less than 10. Morphological and nitrogen content analyze were done on 4 species : Quercus lineata, G. rostrata, A. excelsa, and E. lineata. Among them, Quercus lineata has highest specific leaf area (SLA (0,01153, followed by G. rostrata (0,00821, A. excelsa (0,00579, and E. lineata (0,00984 g/cm2. The highest number of stomata was found on A. excelsa (85,10/mm2, followed by E. lineata (74,40/mm2, Q. lineata (53,70/mm2, and G. rostrata (18,4 /mm2. The emergent species (A. excelsa and Q. lineata have higher nitrogen content than the underlayer species (G. rostrata and E. lineata. A. excelsa have highest nitrogen use efficiency (28,19% compare to E. lineata (23,81% , Q. lineata (19,09%, and G. rostrata (14,87%. Although not significant, emergen species have higher NUE than underlayer species.
17. Residuos de plaguicidas organoclorados en 4 tipos de aceites vegetales / Organochlorine pesticide residues in 4 types of vegetable oils.
Scientific Electronic Library Online (English)
María, Piñero González; Pedro, Izquierdo Córser; María, Allara Cagnasso; Aiza, García Urdaneta.
2007-12-01
Full Text Available Esta investigación tuvo como objetivos identificar y cuantificar residuos de los plaguicidas organoclorados (POC) hexaclorobenceno (HCB), lindano, cis-clordano, heptacloro, aldrín, dieldrín, endrín y o,p’-diclorodifeniltricloroetano (o,p’-DDT) en aceites de maíz, soya, girasol y mezclas de aceites, [...] que se expenden en la ciudad de Maracaibo, Venezuela. Se analizaron 30 muestras de 4 tipos de aceites de 10 marcas comerciales. La extracción de residuos de POC se realizó según la técnica de la AOAC. Para la identificación y cuantificación se utilizó un cromatógrafo de gases con detector de captura electrónica (GC-ECD), y para la confirmación, un cromatógrafo de gases acoplado a un espectrómetro de masas (GCMS). Todos los residuos de POC investigados fueron detectados en las muestras analizadas. Se detectaron en mayor concentración (mg/ g) aldrín (0,0088), lindano (0,0054) y o,p’-DDT (0,0035). El análisis estadístico demostró diferencias significativas (P Abstract in english The present study had as objectives to identify and to quantify organochlorine pesticide residues (OCP) hexachlorobenzene (HCB), lindane, cis-chlordane, heptachlor, aldrín, dieldrín, endrín and o,p’-DDT in vegetable oils of corn, soybean, sunflower and mixtures of oils, sold in the city of Maracaibo [...] , Venezuela. 30 samples of 4 types of vegetable oils of 10 commercial brands were analyzed. The extraction of OCP residues was done according to the Official Method of AOAC. A gas chromatograph with an electronic capture detector (GC-ECD) was used for identification and quantification of OCP residues and confirmation was done with a gas chromatograph coupled with a mass spectrometer (GC-MS). All the OCP residues investigated were detected in the analyzed samples. Aldrin (0.0088), lindane (0.0054) and o,p’-DDT (0.0035) were the OCP residues detected in higher concentrations (mg/g). The statistical analysis showed significant differences (P
18. Ecological and socioeconomic correlates of fruit, juice, and vegetable consumption among African-American boys. — Measures of the Food Environment
Science.gov (United States)
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19. Spatial Vegetation Data for Tuzigoot National Monument Vegetation Mapping Project
National Park Service, Department of the Interior — The vegetation units on this map were determined through the stereoscopic interpretation of aerial photographs supported by field sampling and ecological analysis....
20. Mapping Congo Basin vegetation types from 300 m and 1 km multi-sensor time series for carbon stocks and forest areas estimation
Directory of Open Access Journals (Sweden)
A. Verhegghen
2012-12-01
Full Text Available This study aims to contribute to the understanding of the Congo Basin forests by delivering a detailed map of vegetation types with an improved spatial discrimination and coherence for the whole Congo Basin region. A total of 20 land cover classes were described with the standardized Land Cover Classification System (LCCS developed by the FAO. Based on a semi-automatic processing chain, the Congo Basin vegetation types map was produced by combining 19 months of observations from the Envisat MERIS full resolution products (300 m and 8 yr of daily SPOT VEGETATION (VGT reflectances (1 km. Four zones (north, south and two central were delineated and processed separately according to their seasonal and cloud cover specificities. The discrimination between different vegetation types (e.g. forest and savannas was significantly improved thanks to the MERIS sharp spatial resolution. A better discrimination was achieved in cloudy areas by taking advantage of the temporal consistency of the SPOT VGT observations. This resulted in a precise delineation of the spatial extent of the rural complex in the countries situated along the Atlantic coast. Based on this new map, more accurate estimates of the surface areas of forest types were produced for each country of the Congo Basin. Carbon stocks of the Basin were evaluated to a total of 49 360 million metric tons. The regional scale of the map was an opportunity to investigate what could be an appropriate tree cover threshold for a forest class definition in the Congo Basin countries. A 30% tree cover threshold was suggested. Furthermore, the phenology of the different vegetation types was illustrated systematically with EVI temporal profiles. This Congo Basin forest types map reached a satisfactory overall accuracy of 71.5% and even 78.9% when some classes are aggregated. The values of the Cohen's kappa coefficient, respectively 0.64 and 0.76 indicates a result significantly better than random.
1. Nutrient release from combustion residues of two contrasting herbaceous vegetation types.
Science.gov (United States)
Hogue, Benjamin A; Inglett, Patrick W
2012-08-01
Fire is a critical regulator of biogeochemical cycles in approximately 40% of the earth's land surface. However, little is known about nutrient release from combustion residues (ash and char) from herbaceous or grassland fires of varying intensity. Much of our knowledge in this area is derived from muffle furnace temperature gradient experiments. Therefore, we used two approaches (muffle and flame burning) to combust herbaceous biomass from contrasting nutrient level sites to estimate the forms and availability of nutrients after fire. Clear differences were measured in total and extractable nutrient concentrations in combustion residues of different plant types, with most carbon (C) and nitrogen (N) being volatilized (>99%), while P remained in high concentrations in the residues. Different combustion methods yielded contrasting results, where temperatures greatly affected nutrient quantity and form in muffle furnace residues, while relatively similar residues resulted from flame combustion at varying intensities. It was also found that only 5% of N and 50% of P remaining in flame combustion residues were extractable. Flame residues appeared to be composed of mixtures of materials (ash and char) created at low (450 °C) muffle temperatures (pH, extractable potassium (K), and extractable NH(4)-N). We attribute dissimilar results of the combustion methods to heterogeneity of combustion (zones of low oxygen availability) and short duration (combustion characterizing natural fires in herbaceous, grassland systems. These results can be adapted to ecosystem level models to better predict nutrient changes that may occur after a fire event. PMID:22664533
2. On variability of evapotranspiration : the role of surface type and vegetation
DEFF Research Database (Denmark)
Ringgaard, Rasmus
2012-01-01
3. Radio-capacity of different types of natural ecosystems (without man) and their ecological standardization principles
International Nuclear Information System (INIS)
In this article the theory of radio-capacity of natural ecosystems (excluding mankind) is applied to the definition of ecological standards for permissible releases in the environment. A specific limit of radionuclide contamination of wild life which can be considered as the basis of an ecological standardization (64-640 kb kg-1) is proposed. BAsic equations for evaluation of maximum permissible releases into a lake ecosystem are presented. Ecological standards for benthos are 10 to 100 times less than the ecological standards for inhabitants of the water column. It is shown that the existing levels of radionuclide contamination of terrestrial slope ecosystems in the 30-km zone around Chernobyl Nuclear Power Plant (NPP) exceed the proposed ecological standards. (authors)
4. Some Ecological Aspects of Little Honeybee (Apis florea F.) and Type of Sugar Contents in Honey in Northeast Thailand
OpenAIRE
Ch. Onlamai; N. Thanee
2004-01-01
This research was carried out at Khon Kaen and Maha Sarakham Provinces in northeastern region of Thailand. The work designed to investigate ecological locations and types of sugar in honey of Little Honeybee (Apis florea F.). The results showed that there were four types of ecological locations found, i.e. cropland and degradation forest, orchard farm, villages, and housing area of government?s official. Five types of sugar contents in honey were found with majority of fructose followed by gl...
5. Variation of vegetation incidence by installation of a slit-type erosion control dam -a study based on mesh data and variation of substrata of habitats-
Science.gov (United States)
Sannoh, Keinosuke; Sawa, Yasuo; Taya, Yuki; Tamai, Nobuyuki
This paper summarizes a field survey on physical features of and vegetation on a dry riverbed around a slit-type erosion control dam in Ozo river. Field surveys cover the range 130m to upstream and 200m to downstream of the dam and were performed in 2001 before the construction, and 2008 and 2009 after the construction. We developed a relationship between physical property of substrata and incidence of species of vegetation on the same property of substrata for each species. This incidence ratio is obtained from the observed data in 2001.Predicted mesh numbers and observed mesh numbers for all species observed in three years were shown in one figure. An estimation line between prediction and observation which is developed by Generalized Linear Mixed Model can give reliable relationship even for cases of sparse incidence of vegetation. It is shown that variation of vegetation incidence can be predicted by physical property of substrata. However, it is also shown that substrata and vegetation in studied area are still under succession stage in short period after the impact of construction.
6. Minimal mechanisms for vegetation patterns in semiarid regions
CERN Document Server
Martinez-Garcia, Ricardo; Hernandez-Garcia, E; Lopez, C
2014-01-01
The minimal ecological requirements for formation of regular vegetation patterns in semiarid systems have been recently questioned. Against the general belief that a combination of facilitative and competitive interactions is necessary, recent theoretical studies suggest that, under broad conditions, nonlocal competition among plants alone may induce patterns. In this paper, we review results along this line, presenting a series of models that yield spatial patterns when finite-range competition is the only driving force. A preliminary derivation of this type of model from a more detailed one that considers water-biomass dynamics is also presented. Keywords: Vegetation patterns, nonlocal interactions
7. Past and future scenarios of the effect of carbon dioxide on plant growth and transpiration for three vegetation types of southwestern France
OpenAIRE
J.-C. Calvet; A.-L. Gibelin; J.-L. Roujean; Martin, E.; Le Moigne, P.; Douville, H.; Noilhan, J.
2008-01-01
The sensitivity of an operational CO2-responsive land surface model (the ISBA-A-gs model of Météo-France) to the atmospheric CO2 concentration, (CO2), is investigated for 3 vegetation types (winter wheat, irrigated maize, coniferous forest). Past (1960) and future (2050) scenarios of (CO2) corresponding to 320 ppm and 550 ppm, respectively, are explored. The sensitivity study is performed for 4 annual ...
8. Some Ecological Aspects of Little Honeybee (Apis florea F. and Type of Sugar Contents in Honey in Northeast Thailand
Directory of Open Access Journals (Sweden)
Ch. Onlamai
2004-01-01
Full Text Available This research was carried out at Khon Kaen and Maha Sarakham Provinces in northeastern region of Thailand. The work designed to investigate ecological locations and types of sugar in honey of Little Honeybee (Apis florea F.. The results showed that there were four types of ecological locations found, i.e. cropland and degradation forest, orchard farm, villages, and housing area of government?s official. Five types of sugar contents in honey were found with majority of fructose followed by glucose, lactose, maltose, and least with sucrose. The highest amounts of sugar in honey were highest in June followed by February, December, January, March, September, April, October and November. All types of sugar had no effect on egg rate, worker, and drone cells except fructose where it had highly significant effect on number of queen cells. A range of 1-1.05 (g ml-1 of total sugar had highly significant effect on number of queen cells, but with higher range number of queen cells was declined
9. Building the United States National Vegetation Classification
Science.gov (United States)
Franklin, S.B.; Faber-Langendoen, D.; Jennings, M.; Keeler-Wolf, T.; Loucks, O.; Peet, R.; Roberts, D.; McKerrow, A.
2012-01-01
The Federal Geographic Data Committee (FGDC) Vegetation Subcommittee, the Ecological Society of America Panel on Vegetation Classification, and NatureServe have worked together to develop the United States National Vegetation Classification (USNVC). The current standard was accepted in 2008 and fosters consistency across Federal agencies and non-federal partners for the description of each vegetation concept and its hierarchical classification. The USNVC is structured as a dynamic standard, where changes to types at any level may be proposed at any time as new information comes in. But, because much information already exists from previous work, the NVC partners first established methods for screening existing types to determine their acceptability with respect to the 2008 standard. Current efforts include a screening process to assign confidence to Association and Group level descriptions, and a review of the upper three levels of the classification. For the upper levels especially, the expectation is that the review process includes international scientists. Immediate future efforts include the review of remaining levels and the development of a proposal review process.
10. The classification, mapping and description of the vegetation of the Rooipoort Nature Reserve, Northern Cape, South Africa
OpenAIRE
Hugo Bezuidenhout
2009-01-01
The need for a scientifically-based wildlife management plan and for more knowledge on vegetation led to an investigation into the plant ecology of the Rooipoort Nature Reserve. The main aim of this study was therefore to classify, describe and map the vegetation of the reserve. The floristic data were analysed according to the Braun-Blanquet procedure using the BBPC suite. The data analysis resulted in the identification of 15 communities that can be grouped into ten major community types. T...
11. Arboreal Ant Assemblages Respond Differently to Food Source and Vegetation Physiognomies: a Study in the Brazilian Atlantic Rain Forest
OpenAIRE
Janete Jane Resende; Paulo Enrique Cardoso Peixoto; Evandro Nascimento Silva; Jacques Hubert Charles Delabie; Gilberto M. M. Santos
2013-01-01
This study aimed to analyze assemblages of arboreal ants in different vegetation physiognomies within the Tropical Moist Forest (Atlantic Rain Forest) domain. The study was carried out at the Michelin Ecological Reserve, State of Bahia, Northeast of Brazil. We used sardine (protein resource) and honey (carbohydrate resource) baits to collect ants foraging in three vegetation types: (1) preserved native forest, (2) forest in regeneration (capoeira) with many invasive plants and (3) a mixed agr...
12. Projected impacts of 21st century climate change on the distribution of potential habitat for vegetation, forest types and major conifer species across Russia.
Science.gov (United States)
Tchebakova, Nadezda; Parfenova, Elena; Cantin, Alan; Shvetsov, Eugene; Soja, Amber; Conard, Susane
2013-04-01
Global simulations have demonstrated the potential for profound effects of GCM-projected climate change on the distribution of terrestrial ecosystems and individual species at all hierarchical levels. We modeled progressions of potential vegetation cover, forest cover and forest types in Russia in the warming climate during the 21st century. We used large-scale bioclimatic models to predict zonal vegetation (RuBCliM), and forest cover (ForCliM) and forest types. A forest type was defined as a combination of a dominant tree conifer and a ground layer. Distributions of vegetation zones (zonobiomes), conifer species and forest types were simulated based on three bioclimatic indices (1) growing degree-days above 5oC ; (2) negative degree-days below 0oC; and (3) an annual moisture index (ratio of growing degree days to annual precipitation). Additionally, the presence/absence of continuous permafrost, identified by active layer depth of 2 m, was explicitly included in the models as limiting the forests and tree species distribution in Siberia. All simulations to predict vegetation change across Russia were run by coupling our bioclimatic models with bioclimatic indices and the permafrost distribution for the baseline period 1971-2000 and for the future decades of 2011-2020, 2041-2050 and 2091-2100. To provide a range of warming we used three global climate models (CGCM3.1, HadCM3 and IPSLCM4) and three climate change scenarios (A1B, A2 and B1). The CGCM model and the B1 scenario projected the smallest temperature increases, and the IPSL model and the A2 scenario projected the greatest temperature increases. We compared the modeled vegetation and the modeled tree species distributions in the contemporary climate to actual vegetation and forest maps using Kappa (K) statistics. RuBioCliM models of Russian zonal vegetation were fairly accurate (K= 0.40). Contemporary major conifer species (Pinus sibirica, Pinus sylvestris, Larix spp., Abies sibirica and Picea obovata) distributions also showed good match with the modeled ranges for the major conifer species from 41% to 78%. Those matches would be higher if only later seral stages were considered, because historically part of the primary conifer forests have been replaced by secondary birch and aspen forests after large disturbances (clearcuts and wildfire). With these projected climates, the zonobiomes would need to shift far to the north in order to reach equilibrium with the change in climate. Under the warmer and drier projected future climate climate, most of Russia would be suitable for the forest-steppe ecotone and grasslands rather than for forests. Water stress tolerant light-needled taiga (Pinus sylvestris and Larix spp.) would have an increased advantage over water-loving dark-needled taiga (Pinus sibica, Abies sibirica, Picea obovata) in a new climate. The permafrost-tolerant L. dahurica taiga would remain the dominant forest type in the many current permafrost areas. Accumulated surface fuel loads due to increased tree mortality from drought, insects and other factors, especially at the southern forest border and in interior Siberia (Yakutia), together with an increase in severe fire weather would also lead to increases in large, high-severity fires, which are expected to facilitate vegetation progression towards equilibrium with the climate.
13. Composição da entomofauna da Floresta Nacional do Araripe em diferentes vegetações e estações do ano / Composition of entomofauna on the Araripe National Forest in different vegetation types and year seasons
Scientific Electronic Library Online (English)
Francisco Roberto de, Azevedo; Maria Andréia Rodrigues de, Moura; Maria Solidade Barbosa, Arrais; Daniel Rodrigues, Nere.
2011-12-01
14. Ecological characteristics and polyphasic taxonomic classification of stable pigment-types of the genus Chroococcus (Cyanobacteria).
Czech Academy of Sciences Publication Activity Database
Ková?ik, L.; Jezberová, Jitka; Komárková, Jaroslava; Kopecký, Ji?í; Komárek, Ji?í
2011-01-01
Ro?. 83, ?. 1 (2011), s. 145-166. ISSN 0032-7786 R&D Projects: GA ?R(CZ) GA525/07/0338; GA AV ?R(CZ) IAA600050704 Institutional research plan: CEZ:AV0Z60170517; CEZ:AV0Z50200510; CEZ:AV0Z60050516 Keywords : chromatic adaptation * Chroococcus * cyanobacteria * ecology * phylogeny * pigment content * pigment mutants * Slovakia * taxonomy * ultrastructure Subject RIV: EF - Botanics Impact factor: 2.521, year: 2011
15. Modelling vegetated dune landscapes
Science.gov (United States)
Baas, A. C. W.; Nield, J. M.
2007-03-01
This letter presents a self-organising cellular automaton model capable of simulating the evolution of vegetated dunes with multiple types of plant response in the environment. It can successfully replicate hairpin, or long-walled, parabolic dunes with trailing ridges as well as nebkha dunes with distinctive deposition tails. Quantification of simulated landscapes with eco-geomorphic state variables and subsequent cluster analysis and PCA yields a phase diagram of different types of coastal dunes developing from blow-outs as a function of vegetation vitality. This diagram indicates the potential sensitivity of dormant dune fields to reactivation under declining vegetation vitality, e.g. due to climatic changes. Nebkha simulations with different grid resolutions demonstrate that the interaction between the (abiotic) geomorphic processes and the biological vegetation component (life) introduces a characteristic length scale on the resultant landforms that breaks the typical self-similar scaling of (un-vegetated) bare-sand dunes.
16. Four types of interference competition and their impacts on the ecology and evolution of size-structured populations and communities
DEFF Research Database (Denmark)
Zhang, Lai; Andersen, Ken Haste
2015-01-01
We investigate how four types of interference competition - which alternatively affect foraging, metabolism, survival, and reproduction - impact the ecology and evolution of size-structured populations. Even though all four types of interference competition reduce population biomass, interference competition at intermediate intensity sometimes significantly increases the abundance of adult individuals and the population[U+05F3]s reproduction rate. We find that foraging and metabolic interference evolutionarily favor smaller maturation size when interference is weak and larger maturation size when interference is strong. The evolutionary response to survival interference and reproductive interference is always larger maturation size. We also investigate how the four types of interference competition impact the evolutionary dynamics and resultant diversity and trophic structure of size-structured communities. Like other types of trait-mediated competition, all four types of interference competition can induce disruptive selection and thus promote initial diversification. Even though foraging interference and reproductive interference are more potent in promoting initial diversification, they catalyze the formation of diverse communities with complex trophic structure only at high levels of interference intensity. By contrast, survival interference does so already at intermediate levels, while reproductive interference can only support relatively smaller communities with simpler trophic structure. Taken together, our results show how the type and intensity of interference competition jointly affect coexistence patterns in structured population models
17. Does the endangered Knysna seahorse, Hippocampus capensis, have a preference for aquatic vegetation type, cover or height?
OpenAIRE
Thomas Hecht; Jacqueline F. Lockyear; Peter R. Teske; Horst Kaiser
2011-01-01
The Knysna seahorse,Hippocampus capensis, is an endangered teleost confined to three South African estuaries. Its abundance within these systems is low and distributions are patchy. Consequently, monitoring population sizes is labour-intensive. The aim of this study was to establish if Knynsa seahorses are associated with specific regions within the estuaries, on which conservation efforts could concentrate. The relationship of Knysna seahorses with aquatic vegetation was analysed in the Knys...
18. Spatial Vegetation Data for Johnstown Flood National Memorial Vegetation Mapping Project
National Park Service, Department of the Interior — Vegetation map of Johnstown Flood National Memorial provides local park-specific names for vegetation types, as well as crosswalks to the National Vegetation...
19. Comparison of different types of coatings in headspace solid phase micro extraction for the analysis of pesticide residues in vegetables and fruits
International Nuclear Information System (INIS)
Despite the continuing development of solid-phase micro extraction (SPME) fiber coatings, their selection presents some difficulties for analytes in choosing the appropriate fiber for a particular application. There are many types of SPME coatings available commercially. The most widely used for determination of pesticide residues in vegetable and fruits are polydimethylsiloxane (PDMS) and polyacrylate (PA). A headspace solid phase micro extraction (HS-SPME) procedure using these two commercialized fibers (PDMS and PA) is presented for the determination of selected groups of organo chlorine and organophosphorus pesticides. The extraction performances of these compounds were compared using these two fibers. The optimal experimental procedures for the adsorption and desorption of pesticides were determined. An explanation for the extraction differences is suggested based on the different thickness, polarity of the polymeric film of fibers and the different extracting matrices. In addition, the higher detector response of the pesticides after addition of aliquots of water and an organic solvent to the vegetable and fruit samples are also discussed. The SPME fibers were reusable until a maximum of 120 extractions. Finally, the optimized procedures were applied successfully for the determination of these compounds in vegetable and fruits samples. Mean recoveries for all pesticides were between 75.0-97 % with RSD below 7 %. (author)
20. [Change trend of vegetation cover in Beijing metropolitan region before and after the 2008 Olympics].
Science.gov (United States)
Sun, Xiao-Peng; Wang, Tian-Ming; Wu, Jian-Guo; Ge, Jian-Ping
2012-11-01
The MODIS-NDVI data from 2000 to 2009 were used to analyze the temporal dynamics and spatial distribution of the vegetation cover in the Beijing metropolitan region before and after the 2008 Olympics. During the study period, the proportion of the significantly increased pixels of NDVI occupied 20.7% while that of the significantly decreased pixels only occupied 4.1% of the total, and the decreasing rate of the NDVI was slightly faster than the increasing rate. The significant changes of the NDVI were mainly concentrated in the low altitude and small slope areas with intensive human activities, and two bands were formed in the plain area, i. e., the vegetation increasing band within the 5th Ring Road and the vegetation decreasing band from the 5th Ring Road to the outside areas of the 6th Ring Road. In the areas with significant vegetation change, there was an obvious transition between the high and low NDVI sections but less change in the medium NDVI section, mainly due to the conversion of land cover type. In the Capital function core area and ecological conservation zones, vegetation change represented a positive trend; while in the urban function expansion area and urban development area, vegetation change had the dual characteristics of both positive and negative trends. A series of ecological engineering projects during the preparatory period of the 2008 Olympics was the main cause of the vegetation increase in the study area. PMID:23431801
1. Establishment of experimental catchments to quantify water use by different vegetation types / Estabelecimento de microbacias experimentais para quantificar uso de água por diferentes tipos de vegetação
Directory of Open Access Journals (Sweden)
Almeida Auro Campi
2010-10-01
Full Text Available AbstractThis paper describes the procedure developed to select representative experimental catchments to quantify water use and water use efficiency of different vegetation types. We combined freely available information such as LANDSAT satellite images, digital elevation model, Google Earth images, streamflow and rainfall historical data, and soils and vegetation data to select the experimental catchments. Once these catchments were indentified, sub-catchments with different vegetation were delineated, which were used to define the distribution and installation of the instrumentation. Forty eight catchments and respective sub-catchments of Tasmania in Australia were analyzed and only two catchments were identified as ideal for the purposes of quantifying and comparing the historic and current water use by Eucalyptus plantation, native forest and pasture. We choose one catchment and created four experimental and instrumented sub-catchments with the following predominant land use: Eucalyptus nitens, native forest and pasture. ResumoO presente artigo descreve o procedimento desenvolvido para selecionar microbacias representativas para quantificar o uso de água e a eficiência do uso de água de diferentes tipos de vegetação. Foram combinadas informações disponíveis sem custo tais como: imagens de satélite LANDSAT, modelo digital do terreno, imagens de Google Earth, escoamento superficial e dados históricos de precipitação pluviométrica, tipos de solos e cobertura vegetal para a seleção de microbacias experimentais. Uma vez identificadas as microbacias, sub-microbacias com diferente tipos de vegetação foram delineadas, as quais foram usadas para definir a distribuição e instalação de instrumentação. Foram analisadas quarenta e oito microbacias e respectivas sub-microbacias na Tasmânia na Austrália e somente duas microbacias foram identificadas como ideais para o propósito de quantificar e comparar o histórico e atual uso de água por plantações de eucalipto, floresta nativa e pastagem. Ao final foi escolhida uma microbacia e quatro sub-microbacias experimentais instrumentadas com o uso de solo predominantemente de Eucalyptus nitens, floresta nativa e pastagem.
2. Diversidad de reptiles en tres tipos de vegetación del estado de Hidalgo, México Diversity of reptiles in three vegetation types of the Hidalgo state, México
Directory of Open Access Journals (Sweden)
Raciel Cruz-Elizalde
2012-06-01
Full Text Available La zona sureste del estado de Hidalgo presenta diversos tipos de vegetación, como el bosque mesófilo de montaña, bosque de pino-encino y bosque de pino, con alta riqueza de reptiles. En este estudio, se analizó la diversidad alfa y beta de los reptiles en los 3 tipos de vegetación presentes en la zona sureste. Durante el periodo de recolección, de junio 2008 a agosto del 2009, se realizaron 12 salidas, 1 por mes, con duración de 3 días cada una. La diversidad de reptiles está compuesta por 25 especies, incluyendo un registro nuevo para el estado, la culebra Thamnophis scaliger. El bosque mesófilo de montaña (BMM presentó la mayor riqueza, con 15 especies, seguido del bosque de pino (BP, con 13, y el bosque de pino-encino (BPE, con 12. Las asociaciones realizadas entre el BMM-BP y BMM-BPE presentaron la más alta disimilitud en especies, y el menor valor fue para el BPE-BP. Este estudio muestra la riqueza y distribución de las especies de los reptiles en los diferentes tipos de vegetación del sureste del estado y presenta nuevos registros de especies para la entidad. El conocimiento de la riqueza de especies por tipos de vegetación de este estudio sienta las bases sobre la biodiversidad, lo que ayuda a plantear estudios dirigidos a la conservación de este grupo.The southeast of Hidalgo in Mexico includes various vegetation types, such as cloud forest, pine-oak forest and pine forest, all harbouring a high species richness of reptiles. In this study we analyzed the alpha and beta diversity of reptiles in 3 vegetation types in the southeast of the state. The field work period was from June 2008 to August 2009, comprising 12 sampling periods of 3 days, 1 per month. The diversity of reptiles is composed of 25 species, reporting the snake Thamnophis scaliger as a new record for the state. The cloud forest (CF has the highest richness, with 15 species, followed by pine forest (PF, with 13, and finally, the pine-oak forest (POF, with 12 species. The associations between the CF-PF and CF-POF showed the highest dissimilarity in species, and the lowest the POF-PF. This study shows the richness and distribution species of the reptiles in the different vegetation types from southeast of the state, presents new records of species from the state and provides the basis for future studies on the biology of some species of reptiles in the area. The knowledge of species richness by vegetation types from this study provides the basis on the biodiversity that help to raise studies directed to the conservation of this group.
3. Conhecimento ecológico tradicional da comunidade de Limpo Grande sobre a vegetação, Várzea Grande, Mato Grosso, Brasil / Traditional ecological knowledge of vegetation in the community of Limpo Grande, Várzea Grande, Mato Grosso, Brazil
Scientific Electronic Library Online (English)
Rodrigo Ferreira de, Morais; Cintia Silva, Serrano; Fernando Ferreira de, Morais.
2015-04-01
4. Cobertura vegetal do estado de São Paulo: I - Levantamento por fotointerpretação das áreas cobertas com cerrado, cerradão e campo, em 1962 / Vegetation covering the state of São Paulo: I - Survey in 1962 by means of photo-interpretation of the areas covered by various types of vegetation
Scientific Electronic Library Online (English)
Mário, Borgonovi; Jorge Vicente, Chiarini.
5. Cobertura vegetal do estado de São Paulo: I - Levantamento por fotointerpretação das áreas cobertas com cerrado, cerradão e campo, em 1962 Vegetation covering the state of São Paulo: I - Survey in 1962 by means of photo-interpretation of the areas covered by various types of vegetation
Directory of Open Access Journals (Sweden)
Mário Borgonovi
1965-01-01
6. Geophysical Applications of Vegetation Modeling
OpenAIRE
Kaplan, J. O.
2001-01-01
This thesis describes the development and selected applications of a global vegetation model, BIOME4. The model is applied to problems in high-latitude vegetation distribution and climate, trace gas production, and isotope biogeochemistry. It demonstrates how a modeling approach, based on principles of plant physiology and ecology, can be applied to interdisciplinary problems that cannot be adequately addressed by direct observations or experiments. The work is relevant to understanding the p...
7. Vegetation type and the presence of ash as factors in the evolution of soil water repellency after a forest fire
Directory of Open Access Journals (Sweden)
P. Jiménez-Pinilla
2013-05-01
Full Text Available After wildfires, burning may induce the occurrence of soil water repellency. Soil water repellency may vary in space and time in function of vegetation, the presence of ash and soil moisture. This study analyzes the evolution of fire-induced soil water repellency in function of these factors, and proposes measures to promote the restoration of fire-affected soils. Burnt and unburnt (control soil plots under pine and shrub from a recently burned area (Gorga, Alicante, SE Spain were established. Three treatments were applied: in some of the plots, the original ash layer was kept on the ground; in a second group, the ash layer was removed for simulating the effects of erosion; finally, in a third group, percolating irrigation was conducted to simulate a possible good input of water into the soil profile after burning, that could occur if the first rains were with high quantity but low intensity. During the dry season, soil moisture content was significantly lower in burned plots due to fire-induced water repellency and reduced vegetation cover. During the wet season, soil moisture decreased in the control unburnt plots due to direct evaporation of water intercepted by vegetation and consumption by roots. Fire increased soil water repellency only in plots under pine. Water repellency decreased during the wet season, disappearing in January and reappearing after declining rainfalls. This baseline recovery of soil water repellency was lower where ash removal was simulated. In unburned plots, seasonal fluctuations were less important. In general, ash removal promotes a rapid reduction of water repellency, since it can induce washing of hydrophobic compounds. Irrigation performed immediately after the fire also contributed to decreased water repellency.
8. On the potential of long wavelength imaging radars for mapping vegetation types and woody biomass in tropical rain forests
Science.gov (United States)
Rignot, Eric J.; Zimmermann, Reiner; Oren, Ram
1995-01-01
In the tropical rain forests of Manu, in Peru, where forest biomass ranges from 4 kg/sq m in young forest succession up to 100 kg/sq m in old, undisturbed floodplain stands, the P-band polarimetric radar data gathered in June of 1993 by the AIRSAR (Airborne Synthetic Aperture Radar) instrument separate most major vegetation formations and also perform better than expected in estimating woody biomass. The worldwide need for large scale, updated biomass estimates, achieved with a uniformly applied method, as well as reliable maps of land cover, justifies a more in-depth exploration of long wavelength imaging radar applications for tropical forests inventories.
9. Mediation of Fire-Climate Linkages by Vegetation Types in Alaskan Arctic Tundra Ecosystems: Impacts of Model Uncertainty on GCM-Based Forecasts of Future Fire Activity
Science.gov (United States)
Duffy, P.; Higuera, P. E.; Young, A. M.; Hu, F.; Dietze, M.
2014-12-01
Fire is a powerful landscape scale disturbance agent in tundra ecosystems. Impacts on biophysical properties (e.g. albedo) and biogeochemical function (e.g. carbon flux) underscore the need to better quantify fire-climate linkages in tundra ecosystems as climate change accelerates at northern high latitudes. In this context, a critical question is "How does the functional linkage between climate and fire vary across spatial domains dominated by different vegetation types?" We address this question with BLM-Alaska Fire Service area burned data (http://fire.ak.blm.gov/predsvcs/maps.php) used in conjunction with downscaled historical climate data from the Scenarios Network for Alaska Planning (http://www.snap.uaf.edu/data.php) to develop gradient boosting models of annual area burned in Alaska tundra ecosystems. The sparse historical fire records in the Arctic necessitate explicit quantification of model uncertainty associated with the development of statistical analyses. In this work, model uncertainty is depicted through the construction of separate models depicting fire-climate relationships for regions defined by the graminoid, shrub, and wetland tundra vegetation classes (Circumpolar Arctic Vegetation Map: http://www.geobotany.uaf.edu/cavm/). Non-linear relationships between annual area burned and climate variables are depicted with partial dependence functions. Our results show that vegetation-specific models result in different non-linear relationships between climate and fire. Precipitation variables generally had higher relative influence scores than temperature; however, differences between the magnitude of the scores were greater when models were built with monthly (versus seasonal) explanatory variables. Key threshold values for climate variables are identified. The impact of model uncertainty on forecasts of future fire activity was quantified using output from five different AR5/CMIP5 General Circulation Models. Model uncertainty corresponding to vegetation-specific functional linkages between climate and fire has a magnitude similar to that of GCM-based model uncertainty. Results of this work strongly suggest that future forecasts of fire activity must account for and quantify sources of uncertainty in order to provide useful information.
10. Influência do sistema de condução e do tipo de solo sobre o crescimento vegetativo da videira Influence of trellis system and soil type on grapevine vegetative growth
Directory of Open Access Journals (Sweden)
Jean Pierre Rosier
1995-01-01
Full Text Available Este trabalho avalia a influência de dois sistemas de condução (lira e espaldeira e do tipo de solo (arenoso e argiloso no crescimento do aparelho vegetativo da videira. As diferenças observadas foram maiores no crescimento dos netos do que no dos sarmentos e estão ligadas à precocidade determinada pelo tipo de solo. Os efeitos da poda verde e do estresse hídrico associados aos sistemas de condução foram os responsáveis pelas diferenças na velocidade de crescimento dos sarmentos e dos netos.This work evaluates the influence of two trellis-training systems (lyre and vertical, and two soil types (sandy and clay on grapevine vegetative growth. The observed differences were greater on axillary shoot growth than on main shoots, and they are linked to the precocity determined by soil type. The effects of summer pruning and hydric stress associated to trellis-training systems were responsible for differences on growth speed of shoots and axillary shoots.
11. Diurnal variation of tension-type headache intensity and exacerbation: An investigation using computerized ecological momentary assessment
Directory of Open Access Journals (Sweden)
Kikuchi Hiroe
2012-09-01
12. Ecologia do forrageio por Cyphomyrmex morschi Emery (Hymenoptera, Formicidae) em vegetação de restinga no Sul do Brasil / Foraging ecology of Cyphomyrmex morschi Emery (Hymenoptera, Formicidae) in sand dune vegetation at Southern Brazil
Scientific Electronic Library Online (English)
Benedito Cortês, Lopes.
2007-03-01
Full Text Available Foram amostrados 400 ninhos de Cyphomyrmex morschi Emery, 1887 entre 1997 e 1998, nas dunas da praia da Joaquina, Florianópolis, SC, para a verificação do material transportado ao ninho. Estas formigas utilizam material de origem vegetal ou animal (fezes de lagartas de Lepidoptera ou partes de corpo [...] s de besouros ou formigas) ou mesmo material não identificado que são introduzidos no ninho para o cultivo do fungo. Assim, do ponto de vista do papel ecológico desempenhado, pode-se considerar C. morschi como uma espécie detritófaga. Abstract in english A total of 400 nests of Cyphomyrmex morschi Emery, 1887 was evaluated between 1997 and 1998 at the dunes of the Joaquina Beach, Florianópolis, Santa Catarina, in order to verify the substrate brought back to the nests. These ants use vegetable or animal material (excrements of lepidopteran larvae or [...] carcasses of beetles or ants) or even not identified material that are used to culture the fungus. Thus, ecologically speaking, C. morschi can be considered a detritiphagous species.
13. Assessments of Drought Impacts on Vegetation in China with the Optimal Time Scales of the Climatic Drought Index
Directory of Open Access Journals (Sweden)
Zheng Li
2015-07-01
Full Text Available Drought is expected to increase in frequency and severity due to global warming, and its impacts on vegetation are typically extensively evaluated with climatic drought indices, such as multi-scalar Standardized Precipitation Evapotranspiration Index (SPEI. We analyzed the covariation between the SPEIs of various time scales and the anomalies of the normalized difference vegetation index (NDVI, from which the vegetation type-related optimal time scales were retrieved. The results indicated that the optimal time scales of needle-leaved forest, broadleaf forest and shrubland were between 10 and 12 months, which were considerably longer than the grassland, meadow and cultivated vegetation ones (2 to 4 months. When the optimal vegetation type-related time scales were used, the SPEI could better reflect the vegetation’s responses to water conditions, with the correlation coefficients between SPEIs and NDVI anomalies increased by 5.88% to 28.4%. We investigated the spatio-temporal characteristics of drought and quantified the different responses of vegetation growth to drought during the growing season (April–October. The results revealed that the frequency of drought has increased in the 21st century with the drying trend occurring in most of China. These results are useful for ecological assessments and adapting management steps to mitigate the impact of drought on vegetation. They are helpful to employ water resources more efficiently and reduce potential damage to human health caused by water shortages.
14. Estimating Hydrologic and Ecological Responses to Increased Climate Variability using Water Year Type Classification
Science.gov (United States)
Null, S. E.
2014-12-01
Water management frameworks that were designed assuming stationary climate conditions will be increasingly difficult to implement in non-stationary climates, presenting a barrier to climate change adaptation and efficient water management for people and ecosystems. Hydrologic indices, or water year classification systems as they are also called, categorize streamflow by year type, such as wet, dry, or normal, compared to historical averages. Numerical thresholds separate water year types, often set by weighted winter and spring runoff volume for rivers. Year type classification is tied to water resources planning, helping to answer the question of whether there is 'enough' water, and water allocations to competing water uses are typically adjusted based on water year type. Hydrologic indices were developed for Utah's Bear, Weber, and Jordan-Provo rivers using long-term reconstructed streamflow from tree-ring data (~1500 to present). Tree-ring data have considerably more variability than measured streamflow from the 20th Century, indicating droughts and wet periods could be longer, more intense, and of greater magnitude than more recent records suggest. Tree-ring reconstructed streamflow is also a promising surrogate to represent increasing future hydroclimatic variability. The Bear, Weber, and Jordan-Provo rivers make up approximately 95% of the streamflow to the Great Salt Lake and supply water to the Salt Lake City, Ogden, and Logan metropolitan areas. The frequency of water year types changes with increased hydroclimatic variability represented in tree-ring reconstructed streamflow when historical year type thresholds or historical year type distributions are maintained. In turn, this affects allocations to urban, agricultural, and environmental water uses, and highlights potential adaptation strategies for watershed-scale water resources management with increased climate variability from climate change.
15. Forest vegetation management in Europe – Czech Republic.
Czech Academy of Sciences Publication Activity Database
Cudlín, Pavel; Ba?a?, P.; Krej?í?, R.
Brussels : COST Office, 2009 - (Willoughby, I.; Balandier, P.; Bentsen, N.; McCarthy, N.; Claridge, J.), s. 7-14 [Ecological forest vegetation management. Vejle (DK), 04.05.2009 -08.05.2009] R&D Projects: GA MŠk OC 141 Institutional research plan: CEZ:AV0Z60870520 Keywords : forest vegetation management * herbicides * alternative methods Subject RIV: GK - Forestry
16. Riparian Vegetation Mapping Along the Hanford Reach
Energy Technology Data Exchange (ETDEWEB)
FOGWELL, T.W.
2003-07-11
During the biological survey and inventory of the Hanford Site conducted in the mid-1990s (1995 and 1996), preliminary surveys of the riparian vegetation were conducted along the Hanford Reach. These preliminary data were reported to The Nature Conservancy (TNC), but were not included in any TNC reports to DOE or stakeholders. During the latter part of FY2001, PNNL contracted with SEE Botanical, the parties that performed the original surveys in the mid 1990s, to complete the data summaries and mapping associated with the earlier survey data. Those data sets were delivered to PNNL and the riparian mapping by vegetation type for the Hanford Reach is being digitized during the first quarter of FY2002. These mapping efforts provide the information necessary to create subsequent spatial data layers to describe the riparian zone according to plant functional types (trees, shrubs, grasses, sedges, forbs). Quantification of the riparian zone by vegetation types is important to a number of DOE'S priority issues including modeling contaminant transport and uptake in the near-riverine environment and the determination of ecological risk. This work included the identification of vegetative zones along the Reach by changes in dominant plant species covering the shoreline from just to the north of the 300 Area to China Bar near Vernita. Dominant and indicator species included Agropyron dasytachyudA. smithii, Apocynum cannabinum, Aristida longiseta, Artemisia campestris ssp. borealis var scouleriana, Artemisa dracunculus, Artemisia lindleyana, Artemisia tridentata, Bromus tectorum, Chrysothamnus nauseosus, Coreopsis atkinsoniana. Eleocharis palustris, Elymus cinereus, Equisetum hyemale, Eriogonum compositum, Juniperus trichocarpa, Phalaris arundinacea, Poa compressa. Salk exigua, Scirpus acutus, Solidago occidentalis, Sporobolus asper,and Sporobolus cryptandrus. This letter report documents the data received, the processing by PNNL staff, and additional data gathered in FY2002 to support development of a complete data layer describing riparian vegetation cover types on the Columbia River adjacent to the Hanford Site boundaries. Included with this report are the preliminary riparian vegetation maps and the associated metadata for that GIS layer.
17. GIS Analysis of Changes in Ecological Vulnerability Using a SPCA Model in the Loess Plateau of Northern Shaanxi, China
OpenAIRE
Kang, Hou; Xuxiang, Li; Jing, Zhang
2015-01-01
Changes in ecological vulnerability were analyzed for Northern Shaanxi, China using a geographic information system (GIS). An evaluation model was developed using a spatial principal component analysis (SPCA) model containing land use, soil erosion, topography, climate, vegetation and social economy variables. Using this model, an ecological vulnerability index was computed for the research region. Using natural breaks classification (NBC), the evaluation results were divided into five types:...
18. Water deficit affects wood vessels of Croton floribundus Spreng. in different vegetation types, São Paulo State, Brazil / Déficit hídrico interfere nos vasos do lenho de Croton floribundus Spreng. em diferentes tipos de vegetação, SP, Brasil
Scientific Electronic Library Online (English)
Eduardo Luiz, Longui; Diego, Romeiro; Luana Naves, Testoni; Osny Tadeu de, Aguiar; Roque, Cielo Filho; Israel Luiz de, Lima; Sandra Monteiro Borges, Florsheim.
2012-03-01
Full Text Available O déficit hídrico influenciou na formação dos vasos da madeira de Croton floribundus ocorrentes em cinco áreas com as seguintes vegetações: Floresta Ombrófila, Floresta Estacional Semidecidual e Cerradão. As variações dos vasos devem-se especialmente ao déficit hídrico e número de meses com déficit [...] hídrico. Vasos de maior diâmetro ocorreram em áreas com maior déficit hídrico, o que pode indicar uma estratégia para otimizar o transporte de água em épocas favoráveis. Vasos com menores diâmetros ocorreram em áreas com menor déficit hídrico, possivelmente influenciados pelas menores temperaturas mínimas e a ocorrência de geadas, que semelhante a seca, causa a embolia dos vasos. Na Estação Ecológica de Caetetus, Floresta Estacional Semidecidual (área com maior déficit de água) observaram-se investimentos em eficiência e segurança, com a ocorrência de vasos de maior diâmetro associados a um dos menores índices de vulnerabilidade e maior proporção de vasos múltiplos de quatro ou mais elementos. Abstract in english In this paper we showed that water deficit affects the wood vessels of Croton floribundus in five areas with different vegetation types: Rain Forest, Semi-deciduous Forest and Woody Savanna. We concluded that variations in the vessels are due especially to water deficit and the number of months with [...] water deficit. Larger diameter vessels occurred in areas with higher water deficit, which may represent a strategy to optimize the water transport in favorable periods. Vessels with smaller diameters occur in areas with lower deficit, which may be related to lower minimum temperatures and frost occurrence, which like drought can cause vessel embolism. In Caetetus Ecological Station, a Semi-deciduous Forest (area of highest water deficit), we observed investments in efficiency and safety, with the occurrence of larger diameter vessels associated with one of the lowest vulnerability indexes and highest proportions of multiple vessels of four or more elements.
19. PATRONES DE LA VEGETACIÓN Y TIPOS DE USO DE LA TIERRA EN EL VALLE DEL PATÍA / Vegetation patterns and land use types in the Patia valley
Scientific Electronic Library Online (English)
Hernando, Vergara Varela.
2015-06-01
20. Ecological half-times of 137Cs and 90Sr in dairy milk in regions with different soil types
International Nuclear Information System (INIS)
Long-lived radionuclides 137Cs and 90Sr have been regularly monitored since the 1960's in dairy milk in Finland. The aim of this work was to study regional differences in long-term behaviour of 137Cs and 90Sr in dairy milk including the nuclear weapons tests period and the period after the Chernobyl fallout. In the milk production areas soil types vary from clayish to organic soils. Although total 137Cs deposition from nuclear weapon testings was about the same in all regions, 137Cs concentrations in dairy milk during the 1960's ranged between 5 and 35 Bq/l being highest in regions with high proportion of peat soils. The uneven deposition after the Chernobyl accident before the start of the growing season gave rise to 137Cs concentrations in dairy milk ranging from 3 Bq/l to 60 Bq/l. The ecological half-times were estimated for the decrease of 137Cs and 90Sr after the end of nuclear weapon tests period and the Chernobyl fallout for short and longer time intervals. In the milk production areas dominated by organic soils the ecological half-times for decrease of 137Cs were twice as long as in the regions with clayish soils. Half-times of 90Sr for longer time intervals were considerably longer than those for 137Cs. This long-term data on behaviour of 137Cs and 90Sr in dairy milk can be utilized in testing food chain models. The incorporation of region specific parameters in models will enhance their usefulness in case of a nuclear accident. (author)
1. Ecological separation in foraging schedule and food type between pollinators of the California wildflower, Clarkia xantiana ssp. xantiana
Directory of Open Access Journals (Sweden)
Vince Eckhart
2010-10-01
Full Text Available The co-occurrence of several dimensions of resource separation between coexisting consumers strengthens the hypothesis that the separation arose from and/or ameliorates interspecific competition. The two most common pollinators of the California endemic plant Clarkia xantiana ssp. xantiana (Onagraceae, the bees Hesperapis regularis (Mellitidae and Lasioglossum pullilabre (Halictidae, are known to partition flower resources by flower colour. Here we asked whether H. regularis and L. pullilabre also partition flower resources by diurnal foraging schedule and by food type (pollen versus nectar. We also quantified diurnal patterns of nectar availability, expected to be related to foraging schedules and forager responses to flower colour. The diurnal schedules of the two species differed distinctly and significantly. The majority of L. pullilabre foraging visits occurred before midday, while the majority of H. regularis visits occurred afterwards. The two species foraged for alternative food types at significantly different frequencies—nectar and pollen approximately equally frequently for H. regularis, pollen almost exclusively for L. pullilabre. Nectar standing crop declined with time of day, but it did not clearly reflect or explain previously identified colour-morph preferences. The major pollinators of C. xantiana ssp. xantiana exhibit multiple forms of ecological separation that likely reduce the intensity of competition for floral resources.
2. Response of Coprophagus Beetles (Coleoptera: Scarabaeidae on changes of vegetation structure in various habitat types at Lore Lindu National Park, Central Sulawesi
Directory of Open Access Journals (Sweden)
CHRISTIAN H. SCHULZE
2007-01-01
Full Text Available This study analysed the response of dung beetles ? a group of beetles which play a major role in decomposition of dung and animal carcasses ? to changes of vegetation structure due to forest conversion to different human-made habitat types at the margin of Lore Lindu National Park. Therefore, dung beetles were sampled at natural forest, cacao agroforestry systems and open area. A total of 28 species of coprophagus beetle species were recorded from the sampled sites. Species richness and abundance of dung beetles, particularly of large species, decreased from forest towards agroforestry systems and open areas. However, more than 80 % of the species recorded in natural forest were found in cacao agroforestry systems Of the measured habitat parameters, particularly the number of tree species, air temperature, and canopy cover had a significant power for explaining changes in dung beetle ensembles along the gradient of land-use intensity.
3. Diversidad de reptiles en tres tipos de vegetación del estado de Hidalgo, México / Diversity of reptiles in three vegetation types of the Hidalgo state, México
Scientific Electronic Library Online (English)
Raciel, Cruz-Elizalde; Aurelio, Ramírez-Bautista.
2012-06-01
Full Text Available La zona sureste del estado de Hidalgo presenta diversos tipos de vegetación, como el bosque mesófilo de montaña, bosque de pino-encino y bosque de pino, con alta riqueza de reptiles. En este estudio, se analizó la diversidad alfa y beta de los reptiles en los 3 tipos de vegetación presentes en la zo [...] na sureste. Durante el periodo de recolección, de junio 2008 a agosto del 2009, se realizaron 12 salidas, 1 por mes, con duración de 3 días cada una. La diversidad de reptiles está compuesta por 25 especies, incluyendo un registro nuevo para el estado, la culebra Thamnophis scaliger. El bosque mesófilo de montaña (BMM) presentó la mayor riqueza, con 15 especies, seguido del bosque de pino (BP), con 13, y el bosque de pino-encino (BPE), con 12. Las asociaciones realizadas entre el BMM-BP y BMM-BPE presentaron la más alta disimilitud en especies, y el menor valor fue para el BPE-BP. Este estudio muestra la riqueza y distribución de las especies de los reptiles en los diferentes tipos de vegetación del sureste del estado y presenta nuevos registros de especies para la entidad. El conocimiento de la riqueza de especies por tipos de vegetación de este estudio sienta las bases sobre la biodiversidad, lo que ayuda a plantear estudios dirigidos a la conservación de este grupo. Abstract in english The southeast of Hidalgo in Mexico includes various vegetation types, such as cloud forest, pine-oak forest and pine forest, all harbouring a high species richness of reptiles. In this study we analyzed the alpha and beta diversity of reptiles in 3 vegetation types in the southeast of the state. The [...] field work period was from June 2008 to August 2009, comprising 12 sampling periods of 3 days, 1 per month. The diversity of reptiles is composed of 25 species, reporting the snake Thamnophis scaliger as a new record for the state. The cloud forest (CF) has the highest richness, with 15 species, followed by pine forest (PF), with 13, and finally, the pine-oak forest (POF), with 12 species. The associations between the CF-PF and CF-POF showed the highest dissimilarity in species, and the lowest the POF-PF. This study shows the richness and distribution species of the reptiles in the different vegetation types from southeast of the state, presents new records of species from the state and provides the basis for future studies on the biology of some species of reptiles in the area. The knowledge of species richness by vegetation types from this study provides the basis on the biodiversity that help to raise studies directed to the conservation of this group.
4. Influence of Soil Type, Sowing Date and Diluted Seawater Irrigation on Seed Germination, Vegetation and Chemical Constituents of Moringa oleifera, Lam.
Directory of Open Access Journals (Sweden)
M. A. Hegazi
2015-02-01
Full Text Available Two pot trials were conducted during the period of February 15 – October 15 of 2012 and 2013 seasons at two different locations, to evaluate the effect of soil type, sowing date and diluted seawater irrigation on: germination percentage in the first trial and on both plant vegetation and leaves chemical constituents of moringa (Moringa oleifera, Lam. in the second one. The results showed that, generally, Kafr El-Sheikh area (Agricultural area where clayey soil and Nile River water is available outperformed Balteem area (coastal area where soil is silty clay and seawater is available in most studied characters. Lowest seawater ratios in Moringa oleifera irrigation water gave the best results for germination %, growth characters and some chemical and mineral contents as total green color, leaf protein, total carbohydrates, nitrogen, potassium, calcium and magnessium whereas, the highest ratios gave the best results for phosphorus and sodium contents.
5. Comprimento da estaca e tipo de substrato na propagação vegetativa de atroveran Shoot cutting length and substrate types on vegetative propagation of atroveran
Directory of Open Access Journals (Sweden)
Larissa Corrêa do Bomfim Costa
2007-08-01
6. Spatial Vegetation Data for Florissant Fossil Beds National Monument Vegetation Mapping Project
National Park Service, Department of the Interior — The vegetation units on this map were determined through the stereoscopic interpretation of aerial photographs supported by field sampling and ecological analysis....
7. MAP OF ECOLOGICAL UNITS IN ROMANIA
OpenAIRE
N. Florea
2005-01-01
The ecological units were delineated based on the ensemble of life conditions whose variety is defined by the specific association of various conditions of climate, relief and lithology, hydrology, vegetable formations and soils, including also the anthropic influence. In the Romania territory 20 ecoregions were delineated, hierarchically grouped in 10 ecological domains and 4 ecological subzones belonging to 2 ecological zones (cold temperate and temperate). Each ecological regions (ecoregio...
8. [Fruits and vegetables].
Science.gov (United States)
Aranceta, Javier
2004-06-01
Fruits and vegetables are particularly interesting for health for their content in minerals, antioxidant vitamins, phytochemicals and dietary fiber. All these substances are related to lower risk for the development of health probems, such as certain types of cancer, cardiovascular diseases, type 2 diabetes, obesity, constipation or diverticolsys. The sound basis of scientific evidence led European and American scientific organizations and societies to recommend an intake up to 150-200 g of vegetables every day; ie. 2 or more portions daily and 3 or more portions of fruit; five portions of fruit and vegetables all together. According to the consumer panel from the Spanish Ministry of Agriculture, Fisheries and Food, between the late 80s and the end of the 90s. consumption of fruit and vegetables decreased. However, in late years this trend has slow down and even reversed. Results from food consumption studies based on individual level assessment in Spain estimate an average consumption of fruit and vegetables of 154 g/per person/day in adults aged 25-60 yr. Prevalence of inadequate intake of fruit and vegetables is high among children and young people. In this age group above 70% of the population consume less than 3 portions of fruit every day on average. Reorientation of prevailing food patterns nowadays require investment in measures aimed at increasing the consumption of plant foods and estimulate healthy food habits in families. PMID:15584475
9. THE GENESIS OF PHOTOSYNTHESIS TYPES AS THE BASIS OF ECOLOGICAL EXPANSION OF HALOPHYTIC PLANTS
Directory of Open Access Journals (Sweden)
Pyurko O.Ye.
2011-12-01
Full Text Available The C3, C4, and CAM photosynthesis types are considerably differed by CO2 absorption intensity, its biochemistry, saturation level, water productivity, biological productivity, and other different features, which secure the plants survival at stress and extreme conditions. The aim of current research was to discover the photosynthesis peculiarities at halophytic plants species (Salicornia europaea L., Halimione pedunculata, Artemisia santonica L., Plantago lanceolata L. by salinity at model and natural conditions, and to generalize data in historical aspect. It was constituted that S. europaea L. was characterized by C3 photosynthesis passage which was switched on CAM CO2 fixation under soil salinity conditions till 4-4,5 %, but glycophyte A.santonica was immanent C4assimilation way of aspartate type.Analysis of literature data and own research allows to find out that in majority the C3photosynthesis dependence from environmental factors described by determinate curve with matched mathematical expression. It was suggested to generalize the data by Lagrange polynomial. The obtained results proved that the pattern of photosynthesis evolution is: C3 ? C4 ? CAM with commute possibilities: C3 ? CAM; C4 ? CAM.
10. Seasonal variation and controlling factors of soil carbon effluxes in six vegetation types in southeast of Sweden
Energy Technology Data Exchange (ETDEWEB)
Tagesson, Torbern (Dept. of Physical Geography and Ecosystem Analysis, Lund Univ., Lund (SE))
2007-11-15
Soil carbon effluxes of a pine stand, a spruce stand, a lichen rock, two oak stands and a meadow in the Laxemar investigation area in south-eastern Sweden (57 deg 5 N, 16 deg 7 E) have been measured with the closed chamber technique at 14 occasions between 23 of March 2004 and 10th of March 2005. Soil temperature at 10 cm depth, air temperature, soil moisture and photosynthetically active radiation (PAR) were also measured. Exponential regressions with soil respiration against air and soil temperature were used to estimate soil respiration between 15th of March 2004 and 14th of March 2005. A light response curve with Gross Primary Production (GPP) against PAR and a cubic regression with GPP against air temperature were used for modelling GPP in meadow for the growing season, 15th of March to 31st of October 2004. The exponential regressions with soil respiration against air and soil temperature explained on average 30.6% and 47.6% of the variation, respectively. Soil moisture had a linear limiting effect on soil respiration for all ecosystems but spruce, where soil moisture was the limiting factor above a threshold value of about 50%vol. In the forest ecosystems, GPP of the ground vegetation were not reducing soil carbon effluxes, while in meadow it was. In meadow, the light response curve with GPP against PAR explained 32.7% of the variation in GPP while the cubic regression against air temperature explained 33.9%. No significant effect of soil moisture on GPP was detected. The exponential regression equations with air and soil temperature against soil respiration could be used to temporally extrapolate the occasional field measurements. The light response curve with GPP against PAR and the cubic regression with GPP against air temperature could also be used for temporal extrapolation. From the modelled soil respiration, annual soil respiration for the ecosystems in Laxemar, during 15th of March 2004 to 14th of March 2005, were estimated to be between 0.56 and 1.18 kg C/m2/y. Annual GPP of meadow was estimated to be between 0.49 and 0.54 kg C/m2/y, which gives a net ecosystem exchange for the meadow of between 0.38 and 0.66 kg C/m2/y, i.e. a significant loss of carbon to the atmosphere
11. Seasonal variation and controlling factors of soil carbon effluxes in six vegetation types in southeast of Sweden
International Nuclear Information System (INIS)
Soil carbon effluxes of a pine stand, a spruce stand, a lichen rock, two oak stands and a meadow in the Laxemar investigation area in south-eastern Sweden (57 deg 5 N, 16 deg 7 E) have been measured with the closed chamber technique at 14 occasions between 23 of March 2004 and 10th of March 2005. Soil temperature at 10 cm depth, air temperature, soil moisture and photosynthetically active radiation (PAR) were also measured. Exponential regressions with soil respiration against air and soil temperature were used to estimate soil respiration between 15th of March 2004 and 14th of March 2005. A light response curve with Gross Primary Production (GPP) against PAR and a cubic regression with GPP against air temperature were used for modelling GPP in meadow for the growing season, 15th of March to 31st of October 2004. The exponential regressions with soil respiration against air and soil temperature explained on average 30.6% and 47.6% of the variation, respectively. Soil moisture had a linear limiting effect on soil respiration for all ecosystems but spruce, where soil moisture was the limiting factor above a threshold value of about 50%vol. In the forest ecosystems, GPP of the ground vegetation were not reducing soil carbon effluxes, while in meadow it was. In meadow, the light response curve with GPP against PAR explained 32.7% of the variation in GPP while the cubic regression against air temperature explained 33.9%. No significant effect of soil moisture on GPP was detected. The exponential regression equations with air and soil temperature against soil respiration could be used to temporally extrapolate the occasional field measurements. The light response curve with GPP against PAR and the cubic regression with GPP against air temperature could also be used for temporal extrapolation. From the modelled soil respiration, annual soil respiration for the ecosystems in Laxemar, during 15th of March 2004 to 14th of March 2005, were estimated to be between 0.56 and 1.18 kg C/m2/y. Annual GPP of meadow was estimated to be between 0.49 and 0.54 kg C/m2/y, which gives a net ecosystem exchange for the meadow of between 0.38 and 0.66 kg C/m2/y, i.e. a significant loss of carbon to the atmosphere
12. The South African National Vegetation Database: History, development, applications, problems and future
Directory of Open Access Journals (Sweden)
Leslie W. Powrie
2012-01-01
Full Text Available Southern Africa has been recognised as one of the most interesting and important areas of the world from an ecological and evolutionary point of view. The establishment and development of the National Vegetation Database (NVD of South Africa enabled South Africa to contribute to environmental planning and conservation management in this floristically unique region. In this paper, we aim to provide an update on the development of the NVD since it was last described, near its inception, more than a decade ago. The NVD was developed using the Turboveg software environment, and currently comprises 46 697 vegetation plots (relevés sharing 11 690 plant taxa and containing 968 943 species occurrence records. The NVD was primarily founded to serve vegetation classification and mapping goals but soon became recognised as an important tool in conservation assessment and target setting. The NVD has directly helped produce the National Vegetation Map, National Forest Type Classification, South African National Biodiversity Assessment and Forest Type Conservation Assessment. With further development of the NVD and more consistent handling of the legacy data (old data sets, the current limitations regarding certain types of application of the data should be significantly reduced. However, the use of the current NVD in multidisciplinary research has certainly not been fully explored. With the availability of new pools of well-trained vegetation surveyors, the NVD will continue to be purpose driven and serve the needs of biological survey in pursuit of sustainable use of the vegetation and flora resources of the southern African subcontinent.
13. The South African National Vegetation Database: history, development, applications, problems and future
Scientific Electronic Library Online (English)
Michael C., Rutherford; Ladislav, Mucina; Leslie W., Powrie.
Full Text Available Southern Africa has been recognised as one of the most interesting and important areas of the world from an ecological and evolutionary point of view. The establishment and development of the National Vegetation Database (NVD) of South Africa enabled South Africa to contribute to environmental plann [...] ing and conservation management in this floristically unique region. In this paper, we aim to provide an update on the development of the NVD since it was last described, near its inception, more than a decade ago. The NVD was developed using the Turboveg software environment, and currently comprises 46 697 vegetation plots (relevés) sharing 11 690 plant taxa and containing 968 943 species occurrence records. The NVD was primarily founded to serve vegetation classification and mapping goals but soon became recognised as an important tool in conservation assessment and target setting. The NVD has directly helped produce the National Vegetation Map, National Forest Type Classification, South African National Biodiversity Assessment and Forest Type Conservation Assessment. With further development of the NVD and more consistent handling of the legacy data (old data sets), the current limitations regarding certain types of application of the data should be significantly reduced. However, the use of the current NVD in multidisciplinary research has certainly not been fully explored. With the availability of new pools of well-trained vegetation surveyors, the NVD will continue to be purpose driven and serve the needs of biological survey in pursuit of sustainable use of the vegetation and flora resources of the southern African subcontinent.
14. Physiolgical and ecological studies of the vegetation on ore deposits, 3; Radioecological symptoms of plants over uranium ore deposits in Koisan, Korea
International Nuclear Information System (INIS)
From 1975 to 1981, the survey was carried out to find out radioecological effects of uranium ore deposits on natural vegetation in Koisan, Korea. The symptoms of spotty and mosaic chlorosis, and necrosis were observed in flowering plants in the areas of uranium ore deposits at Deok-Peung-Ri A, B, and C in Koisan. Although 13 species were found to be chlorosis and necrosis, foliages observed are small and very rare. The features of these symptoms closely resemble those occured by the effects of heavy metals. The amount of transparent radiation throughout the depth of soils from uranium radiation sources decreases exponentially. The mean contents in leaves of spotty and mosaik chlorotic plants, and soils were 1.36?1.53 and 5.3?7.4ppm, respectively
15. Assessments of Drought Impacts on Vegetation in China with the Optimal Time Scales of the Climatic Drought Index.
Science.gov (United States)
Li, Zheng; Zhou, Tao; Zhao, Xiang; Huang, Kaicheng; Gao, Shan; Wu, Hao; Luo, Hui
2015-07-01
Drought is expected to increase in frequency and severity due to global warming, and its impacts on vegetation are typically extensively evaluated with climatic drought indices, such as multi-scalar Standardized Precipitation Evapotranspiration Index (SPEI). We analyzed the covariation between the SPEIs of various time scales and the anomalies of the normalized difference vegetation index (NDVI), from which the vegetation type-related optimal time scales were retrieved. The results indicated that the optimal time scales of needle-leaved forest, broadleaf forest and shrubland were between 10 and 12 months, which were considerably longer than the grassland, meadow and cultivated vegetation ones (2 to 4 months). When the optimal vegetation type-related time scales were used, the SPEI could better reflect the vegetation's responses to water conditions, with the correlation coefficients between SPEIs and NDVI anomalies increased by 5.88% to 28.4%. We investigated the spatio-temporal characteristics of drought and quantified the different responses of vegetation growth to drought during the growing season (April-October). The results revealed that the frequency of drought has increased in the 21st century with the drying trend occurring in most of China. These results are useful for ecological assessments and adapting management steps to mitigate the impact of drought on vegetation. They are helpful to employ water resources more efficiently and reduce potential damage to human health caused by water shortages. PMID:26184243
16. Avaliação dos índices de vegetação NDVI, SR e TVI na discriminação de fitofisionomias dos ambientes do Pantanal de Cáceres/MT / Evaluation of vegetation indexes NDVI, SR and TVI in the discrimination of vegetation types of environments of 'Pantanal' in Cáceres, Mato Grosso State
Scientific Electronic Library Online (English)
Edinéia Aparecida dos Santos, Galvanin; Sandra Mara Alves da Silva, Neves; Carla Bernadete Madureira, Cruz; Ronaldo José, Neves; Paulo Henrique Hack de, Jesus; Jesã Pereira, Kreitlow.
2014-09-01
Full Text Available Este artigo faz uma comparação dos índices de vegetação Normalized Difference Vegetation Index (NDVI), Simple Ratio (SR) e Transformed Vegetation Index (TVI), na discriminação das fitofisionomias de três ambientes do Pantanal de Cáceres, Mato Grosso, considerando a sazonalidade (períodos seco e úmid [...] o). As imagens utilizadas foram as do satélite Landsat TM 5, do ano de 2009 (período seco) e de 2010 (período úmido). As análises mostraram que o NDVI apresentou melhor desempenho em relação ao SR e TVI para os diferentes ambientes. Abstract in english This paper compares the performance of some vegetation indexes: Normalized Difference Vegetation Index (NDVI), Simple Ratio (SR) e Transformed Vegetation Index (TVI), applied in seasonal periods to verify which one best fits to discriminate the vegetation types of environments of 'Pantanal' in Cácer [...] es, Mato Grosso state, Brazil, in Landsat TM 5 image of 2009 in the dry period and 2010 in the humid period. Result verification of indexes images showed that NDVI provide a better performance than the SR and TVI indexes for different environments.
17. The ecology of dark matter haloes -I. The rates and types of halo interactions
Science.gov (United States)
L'Huillier, Benjamin; Park, Changbom; Kim, Juhan
2015-07-01
Interactions such as mergers and flybys play a fundamental role in shaping galaxy morphology. Using the Horizon Run 4 cosmological N-body simulation, we studied the frequency and type of halo interactions, and their redshift evolution as a function of the environment defined by the large-scale density, pair separation, mass ratio, and target halo mass. Most interactions happen at large-scale density contrast ? ? 20, regardless of the redshift corresponding to groups and relatively dense part of filaments. However, the fraction of interacting target is maximum at ? ? 1000. We provide a new empirical fitting form for the interaction rate as a function of the halo mass, large-scale density, and redshift. We also report the existence of two modes of interactions from the distributions of mass ratio and relative distance, implying two different physical origins of the interaction. Satellite targets lose their mass as they proceed deeper into the host halo. The relative importance of these two trends strongly depends on the large-scale density, target mass, and redshift.
18. The ecology of dark matter haloes I: The rates and types of halo interactions
CERN Document Server
L'Huillier, Benjamin; Kim, Juhan
2015-01-01
Interactions such as mergers and flybys play a fundamental role in shaping galaxy morphology. Using the Horizon Run 4 cosmological N-body simulation, we studied the frequency and type of halo interactions, and their redshift evolution as a function of the environment defined by the large-scale density, pair separation, mass ratio, and target halo mass. Most interactions happen at large-scale density contrast $\\delta \\approx 20$, regardless of the redshift, corresponding to groups and relatively dense part of filaments. However, the fraction of interacting target is maximum at $\\delta \\approx 1000$. We provide a new empirical fitting form for the interaction rate as a function of the halo mass, large-scale density, and redshift. We also report the existence of two modes of interactions from the distributions of mass ratio and relative distance, implying two different physical origins of the interaction. Satellite targets lose their mass as they proceed deeper into the host halo. The relative importance of thes...
19. THE STUDY OF VEGETATION FOR A DIAGNOSTICAL EVALUATION OF AGRICULTURAL LANDSCAPES. SOME EXAMPLES FROM LOMBARDY
Directory of Open Access Journals (Sweden)
V. INGEGNOLI
2006-01-01
Full Text Available Considering that a landscape is much more than a set of spatial characters, I tried to focus its ecological elements and processes, proposing (a new concepts (e.g. ecocenotope, ecotissue, (b new functions (e.g. biological and territorial aspects of vegetation (c new applications (e.g. evaluation of vegetation, etc.. To verify these applications, a study on the landscape agricultural units of the hinterland of Milan (about 45° 26’N - 09° 17E, 100 m osl is in process in these years. The characters of some forested tesserae along a transect between the Adda river and the Ticino river (East to West, passing through Milan have been expressed, using the biological integrated method of vegetation survey proposed by Ingegnoli (2002. An example of how to use the ecological characters of all the different types of vegetation existing within a landscape unit is given by the study of corridors and crop fields. A comparison among 3 landscape units has been done, to demonstrate the diagnostic evaluation method, after a parametric analysis based on landscape ecological indexes.
20. Ecology of Listeria spp. in a fish farm and molecular typing of Listeria monocytogenes from fish farming and processing companies.
Science.gov (United States)
Miettinen, Hanna; Wirtanen, Gun
2006-11-01
This study focused on the ecology of Listeria monocytogenes in a fish farm by following the changes in its occurrence in different types of samples for a three year period. In addition, L. monocytogenes isolates from different seafood industry areas were compared with pulsed field gel electrophoresis (PFGE) typing to discover possible associations between primary production, further processing and final products. Weather conditions were found to have a strong influence on the probability of finding Listeria spp. in a fish farm environment. The number of samples contaminated with Listeria spp. was typically bigger after rainy periods. Brook and river waters as well as other runoff waters seemed to be the main contamination source at the farm studied. The farmed fish originally found to carry L. monocytogenes become gradually Listeria free. The time needed for the purification of the fish was several months. The sea bottom soil samples were the ones that preserved the L. monocytogenes contamination the longest time. It can be stated that the fish and fish farm equipment studied did not spread listeria contamination. On the contrary, they were found to suffer from listeria contamination coming from outside sources like the brook water. There was a wide range of different L. monocytogenes PFGE-pulsotypes (30) found at 15 Finnish fish farms and fish processing factories. L. monocytogenes isolates from the final products often belonged to the same pulsotypes as did the isolates from the processing environment as well as from the raw fish. This suggests that, in addition to the fish processing factory environment, the fish raw materials are important sources of L. monocytogenes contamination in final products. PMID:16842875
1. Kuchler Vegetation
California Department of Resources — Digital version of potential natural plant communites as compiled and published on 'Map of the Natural Vegetation of California' by A. W. Kuchler, 1976. Source map...
2. Wetland vegetation establishment in L-Lake
Energy Technology Data Exchange (ETDEWEB)
Kroeger, S.R.
1990-07-01
Wetland vegetation was transplanted from PAR Pond to L-Lake between January and August, 1987. Approximately 100,000 individual plants representing over 40 species were transplanted along the southern shoreline. Three zones of vegetation were created: (1) submersed/floating-leaved, (2) emergent, (3) upper emergent/shrub. During the summers of 1987, 1988, 1989, the Savannah River Ecology Laboratory sampled the vegetation in 54 permanent transects located in planted (N=32) and unplanted areas (N=22). The 1989 vegetation data from L-Lake were compared to 1985 data from PAR Pond.
3. Wetland vegetation establishment in L-Lake
International Nuclear Information System (INIS)
Wetland vegetation was transplanted from PAR Pond to L-Lake between January and August, 1987. Approximately 100,000 individual plants representing over 40 species were transplanted along the southern shoreline. Three zones of vegetation were created: (1) submersed/floating-leaved, (2) emergent, (3) upper emergent/shrub. During the summers of 1987, 1988, 1989, the Savannah River Ecology Laboratory sampled the vegetation in 54 permanent transects located in planted (N=32) and unplanted areas (N=22). The 1989 vegetation data from L-Lake were compared to 1985 data from PAR Pond
4. Studies of vegetation?environment relationships and vegetation dynamics in Chinese subtropical forests
OpenAIRE
Liu, Hai-Ying
2008-01-01
Abstract The principal aim of this study was to investigate vegetation-environment relationships and examine patterns of changes in forest understorey vegetation in five Chinese subtropical forests. Furthermore, an Ecological Field Theory (EFT) model for single-tree influence on understorey vegetation was applied to assess the relative contributions of tree influence to variation in understorey species composition. In focus are five study areas, located in the southern and southwestern part...
5. Lake Victoria wetlands and the ecology of the Nile tilapia, oreochromis niloticus linn,.
OpenAIRE
Balirwa, J.S.
1998-01-01
An ecological study of wetlands was undertaken in northern Lake Victoria (East Africa) between 1993 and 1996 with a major aim of characterising shallow vegetation-dominated interface habitats, and evaluating their importance for fish, in particular, for the stocked and socio-economically important Oreochromis niloticus LINNÉ (the Nile tilapia). From field and laboratory experiments, five major habitat types could be defined by the type of the dominant emergent macrophyte at the shore from the...
6. Fire-mediated disruptive selection can explain the reseeder-resprouter dichotomy in Mediterranean-type vegetation.
Science.gov (United States)
Altwegg, Res; De Klerk, Helen M; Midgley, Guy F
2015-02-01
7. VEGETABLE MARKETING – A SYNTHETIC EVALUATION
Directory of Open Access Journals (Sweden)
CORNELIA ALBOIU
2009-05-01
Full Text Available The paper studies the role of business relationships in the Romanian vegetable supply chain. The analysis reveals that informal contractual relationships are prevalent on the market while in many cases contractual enforcement is at stake. This situation leads to increased uncertainty in terms of what vegetable to produce and where to sell and it negatively impacts the farmers’ revenues and investment decision. The paper employs a qualitative analysis in order to assess the main vegetable commercialization channels including vegetable processing companies and the type of contractual relationship between parts.
8. Terrestrial ecology
International Nuclear Information System (INIS)
The main effort of the Terrestrial Ecology Division has been redirected to a comprehensive study of the Espiritu Santo Drainage Basin located in northeastern Puerto Rico. The general objective are to provide baseline ecological data for future environmental assessment studies at the local and regional levels, and to provide through an ecosystem approach data for the development of management alternatives for the wise utilization of energy, water, and land resources. The interrelationships among climate, vegetation, soils, and man, and their combined influence upon the hydrologic cycle will be described and evaluated. Environmental management involves planning and decision making, and both require an adequate data base. At present, little is known about the interworkings of a complete, integrated system such as a drainage basin. A literature survey of the main research areas confirmed that, although many individual ecologically oriented studies have been carried out in a tropical environment, few if any provide the data base required for environmental management. In view of rapidly changing socio-economic conditions and natural resources limitations, management urgently requires data from these systems: physical (climatological), biological, and cultural. This integrated drainage basin study has been designed to provide such data. The scope of this program covers the hydrologic cycle as it is affected by the interactions of the physical, biological, and cultural systems
9. General ecology of wetlands.
Czech Academy of Sciences Publication Activity Database
Hejný, Slavomil; Segal, S.; Raspopov, I. M.
Cambridge : University Press, 1998 - (Westlake, D.; Kv?t, J.; Szczepanski, A.), s. 1-77 ISBN 0-521-22822-0 R&D Projects: GA ?R GA206/98/0727; GA AV ?R KSK2017602 Keywords : habitats * wetland vegetation * wetland clasification Subject RIV: EH - Ecology, Behaviour
10. Vegetation of the rock habitats of the Sekhukhuneland Centre of Plan Endemism, South Africa
Directory of Open Access Journals (Sweden)
S. J. Siebert
2003-12-01
Full Text Available A hierarchical classification, description, and ecological and floristic interpretations are presented on the vegetation types of the ultramafic rock habitats of the Sekhukhuneland Centre of Plant Endemism. Relevés were compiled in 100 stratified random plots. A TWINSPAN classification, refined by Braun-Blanquet procedures, revealed 17 plant communities, which are classified into 13 associations belonging to four proposed alliances. Many new syntaxa are ecologically interpreted and described. For each syntaxon, the species richness, endemism and conservation status was determined. Much of the plant community distribution can be ascribed to specific habitat preference. The floristic and habitat information, proposed classification, general description and vegetation key are provided to aid future identification of conservation areas, land use planning and research. An ordination (DECORANA based on floristic data confirmed potential relationships that could exist between the plant communities and associated habitats and environmental gradients.
11. Desempenho de um trator operando em solo com diferentes tipos de cobertura vegetal / Tractor performance in soil with different types of plants covering
Scientific Electronic Library Online (English)
Antonio, Gabriel Filho; Suedêmio de L., Silva; Alcir J., Modolo; João C. M. da, Silveira.
2004-12-01
12. Desempenho de um trator operando em solo com diferentes tipos de cobertura vegetal Tractor performance in soil with different types of plants covering
Directory of Open Access Journals (Sweden)
Antonio Gabriel Filho
2004-12-01
13. Past and future scenarios of the effect of carbon dioxide on plant growth and transpiration for three vegetation types of southwestern France
Directory of Open Access Journals (Sweden)
J.-C. Calvet
2007-04-01
Full Text Available The sensitivity of an operational CO2-responsive land surface model (the ISBA-A-gs model of Météo-France to the atmospheric CO2 concentration, [CO2], is investigated for 3 vegetation types (winter wheat, irrigated corn, coniferous forest. Past (1960 and future (2050 scenarios of [CO2] corresponding to 320 ppm and 550 ppm, respectively, are explored. The sensitivity study is performed for 4 annual cycles presenting contrasting conditions of precipitation regime and air temperature, based on continuous measurements performed on the SMOSREX site near Toulouse, in southwestern France. A significant CO2-driven reduction of canopy conductance is simulated for the irrigated corn and the coniferous forest. The reduction is particularly large for corn, from 2000 to 2050 (–18%, and triggers a drop in optimum irrigation (–30 mm y?1. In the case of wheat, the response is more complex, with an equal occurrence of enhanced or reduced canopy conductance.
14. Past and future scenarios of the effect of carbon dioxide on plant growth and transpiration for three vegetation types of southwestern France
Directory of Open Access Journals (Sweden)
J.-C. Calvet
2008-01-01
Full Text Available The sensitivity of an operational CO2-responsive land surface model (the ISBA-A-gs model of Météo-France to the atmospheric CO2 concentration, (CO2, is investigated for 3 vegetation types (winter wheat, irrigated maize, coniferous forest. Past (1960 and future (2050 scenarios of (CO2 corresponding to 320 ppm and 550 ppm, respectively, are explored. The sensitivity study is performed for 4 annual cycles presenting contrasting conditions of precipitation regime and air temperature, based on continuous measurements performed on the SMOSREX site near Toulouse, in southwestern France. A significant CO2-driven reduction of canopy conductance is simulated for the irrigated maize and the coniferous forest. The reduction is particularly large for maize, from 2000 to 2050 (?18%, and triggers a drop in optimum irrigation (?30 mm y?1. In the case of wheat, the response is more complex, with an equal occurrence of enhanced or reduced canopy conductance.
15. Historical and Contemporary Geographic Data Reveal Complex Spatial and Temporal Responses of Vegetation to Climate and Land Stewardship
Directory of Open Access Journals (Sweden)
Miguel L. Villarreal
2013-05-01
Full Text Available Vegetation and land-cover changes are not always directional but follow complex trajectories over space and time, driven by changing anthropogenic and abiotic conditions. We present a multi-observational approach to land-change analysis that addresses the complex geographic and temporal variability of vegetation changes related to climate and land use. Using land-ownership data as a proxy for land-use practices, multitemporal land-cover maps, and repeat photography dating to the late 19th century, we examine changing spatial and temporal distributions of two vegetation types with high conservation value in the southwestern United States: grasslands and riparian vegetation. In contrast to many reported vegetation changes, notably shrub encroachment in desert grasslands, we found an overall increase in grassland area and decline of xeroriparian and riparian vegetation. These observed change patterns were neither temporally directional nor spatially uniform over the landscape. Historical data suggest that long-term vegetation changes coincide with broad climate fluctuations while fine-scale patterns are determined by land-management practices. In some cases, restoration and active management appear to weaken the effects of climate on vegetation; therefore, if land managers in this region act in accord with on-going directional changes, the current drought and associated ecological reorganization may provide an opportunity to achieve desired restoration endpoints.
16. Spatial Vegetation Data for Sagamore Hill National Historic Site Vegetation Mapping Project
National Park Service, Department of the Interior — This shapefile is the final vegetation map of Sagamore Hill National Historic Site that provides local names for vegetation types, as well as crosswalks to the...
17. Spatial Vegetation Data for Gettysburg National Military Park and Eisenhower National Historic Site Vegetation Mapping Project
National Park Service, Department of the Interior — Vegetation map of Gettysburg National Military Park and Eisenhower National Historic Site provides local park-specific names for vegetation types, as well as...
18. Spatial Vegetation Data for Allegheny Portage Railroad National Historic Site Vegetation Mapping Project
National Park Service, Department of the Interior — Vegetation map of Allegheny Portage Railroad National Historic Site provides local park-specific names for vegetation types, as well as crosswalks to the National...
19. Spatial Vegetation Data for Upper Delaware Scenic and Recreational River Vegetation Mapping Project
National Park Service, Department of the Interior — Vegetation map of the Upper Delaware Scenic and Recreational River provides local park-specific names for vegetation types, as well as crosswalks to the National...
20. Behavior of the vegetable crops section in three types of food retail stores in Campo Grande, Brazil Desempenho da seção de hortaliças em equipamentos varejistas de alimentos
Directory of Open Access Journals (Sweden)
Dario de O Lima-Filho
2009-03-01
1. Behavior of the vegetable crops section in three types of food retail stores in Campo Grande, Brazil / Desempenho da seção de hortaliças em equipamentos varejistas de alimentos
Scientific Electronic Library Online (English)
Dario de O, Lima-Filho; Anderson S, Hokama; Caroline P, Spanhol.
2009-03-01
2. Alien plants invade more phylogenetically clustered community types and cause even stronger clustering.
Czech Academy of Sciences Publication Activity Database
Losová, Z.; de Bello, Francesco; Chytrý, M.; Kühn, I.; Pyšek, Petr; Sádlo, Ji?í; Winter, M.; Zelený, D.
2015-01-01
Ro?. 24, ?. 7 (2015), 786-794. ISSN 1466-822X R&D Projects: GA ?R GAP505/12/1296; GA ?R GB14-36079G Institutional support: RVO:67985939 Keywords : biological invasions * phylogenetic diversity * vegetation type Subject RIV: EH - Ecology , Behaviour Impact factor: 6.531, year: 2014
3. The importance of evolutionary history in studies of plant physiological ecology: examples from cerrados and forests of central Brazil / A importância da história evolutiva em estudos de ecofisiologia vegetal: exemplos dos cerrados e florestas do Brasil Central
Scientific Electronic Library Online (English)
William A., Hoffmann; Augusto C., Franco.
2008-09-01
4. Fermented Vegetables
Science.gov (United States)
This chapter is organized into several sections. The first has information on the history of vegetable fermentation research in the US, dating back to the late 1880s. A overview of commercial cucumber and sauerkraut fermentation practices follows, focusing on the US market, although there is some me...
5. Vegetative propagation.
Czech Academy of Sciences Publication Activity Database
Klimešová, Jitka
Berkeley and Los Angeles : University of California Press, 2011 - (Simberloff, D.; Rejmánek, M.), 678-679 ISBN 978-0-520-26421-2 Institutional research plan: CEZ:AV0Z60050516 Keywords : clonal growth * vegetative regeneration * mechanical control Subject RIV: EF - Botanics
6. Diversity of subalpine and alpine vegetation of the eastern part of the Nízke Tatry Mts in Slovakia: major types and environmental gradients.
Czech Academy of Sciences Publication Activity Database
Sekulová, L.; Hájek, Michal
2009-01-01
Ro?. 64, ?. 5 (2009), s. 908-918. ISSN 0006-3088 Institutional research plan: CEZ:AV0Z60050516 Keywords : alpine vegetation * gradients * phytosociology Subject RIV: EF - Botanics Impact factor: 0.617, year: 2009
7. Final vegetative cover for closed waste sites
Energy Technology Data Exchange (ETDEWEB)
Cook, J.R.; Salvo, S.K.
1993-01-22
Low-level, hazardous, and mixed waste disposal sites normally require some form of plant material to prevent erosion of the final closure cap. Waste disposal sites are closed and capped in a complex scientific manner to minimize water infiltration and percolation into and through the waste material. Turf type grasses are currently being used as an interim vegetative cover for most sites. This coverage allows for required monitoring of the closure cap for settlement and maintenance activities. The purpose of this five year study was to evaluate plant materials for use on wastes sites after the post-closure care period that are quickly and easily established and economically maintained, retard water infiltration, provide maximum year-round evapotranspiration, are ecologically acceptable and do not harm the closure cap. The results of the study suggest that two species of bamboo (Phyllostachys (P.) bissetii and P. rubromarginata) can be utilized to provide long lived, low maintenance, climax vegetation for the waste sites after surveillance and maintenance requirements have ceased.
8. Final vegetative cover for closed waste sites
International Nuclear Information System (INIS)
Low-level, hazardous, and mixed waste disposal sites normally require some form of plant material to prevent erosion of the final closure cap. Waste disposal sites are closed and capped in a complex scientific manner to minimize water infiltration and percolation into and through the waste material. Turf type grasses are currently being used as an interim vegetative cover for most sites. This coverage allows for required monitoring of the closure cap for settlement and maintenance activities. The purpose of this five year study was to evaluate plant materials for use on wastes sites after the post-closure care period that are quickly and easily established and economically maintained, retard water infiltration, provide maximum year-round evapotranspiration, are ecologically acceptable and do not harm the closure cap. The results of the study suggest that two species of bamboo (Phyllostachys (P.) bissetii and P. rubromarginata) can be utilized to provide long lived, low maintenance, climax vegetation for the waste sites after surveillance and maintenance requirements have ceased
9. Effect of vegetation switch on soil chemical properties.
Czech Academy of Sciences Publication Activity Database
Iwashima, N.; Masunaga, T.; Fujimaki, R.; Toyota, Ayu; Tayasu, I.; Hiura, T.; Kaneko, N.
2012-01-01
Ro?. 58, ?. 6 (2012), s. 783-792. ISSN 0038-0768 Institutional support: RVO:60077344 Keywords : earthworm * litter * nutrient cycling * soil chemical properties * vegetation switch Subject RIV: EH - Ecology, Behaviour Impact factor: 0.889, year: 2012
10. Ecological land classification and terrestrial environment effects assessment for the Port Hope and Port Granby projects
International Nuclear Information System (INIS)
The Ecological Land Classification system was developed to provide a standardized methodology for describing plant communities and wildlife habitat in southern Ontario. The method employs a hierarchical classification system. It can be applied at different levels of accuracy, i.e., at regional, sub-regional, and local scales with an increasing differentiation of vegetation communities. The standardization of the approach permits a comparison of vegetation communities from different sites and an evaluation of the rarity of these communities within the province. Further, the approach facilitates the monitoring of changes in terrestrial communities with time. These characteristics make Ecological Land Classification mapping a useful tool for environmental assessment such as the ones undertaken for the Port Hope and Port Granby Long-Term Waste Management Projects, which were conducted pursuant to the Canadian Environmental Assessment Act 1992. In the context of the Environmental Assessment for the Port Hope and Port Granby Projects, an Ecological Land Classification study was undertaken to characterize the terrestrial environment at regional, local and site levels. Vegetation patches (polygons) were delineated on the basis of air photo interpretation. The individual polygons were then visited for detailed inventory and classified to the most detailed level; that is to the vegetation type. Plant communities were then compared with those listed in the Ontario Natural Heritathose listed in the Ontario Natural Heritage Information Centre database to determine their rarity and to determine where they rank as Valued Ecosystem Components. Ecological Land Classification mapping results were used in the assessment of effects to Valued Ecosystem Components. A spatial analysis of the digitized vegetation maps showed the geographic extent of habitat losses and impairments due to various project works and activities. Landscape rehabilitation strategies and concepts were subsequently developed based on Ecological Land Classification inventory data and predicted effects. (author)
11. Tipos de estacas e substratos na propagação vegetativa da menta (Mentha arvensis L.) / Types of cuttings and substrates in the vegetative propagation of mint (Mentha arvensis L.)
Scientific Electronic Library Online (English)
H.T.R, Amaro; J.R, Silveira; A.M.S de S, David; M.A.V de, Resende; J.A.S., Andrade.
12. Lower vegetable protein intake and higher dietary acid load associated with lower carbohydrate intake are risk factors for metabolic syndrome in patients with type 2 diabetes: Post-hoc analysis of a cross-sectional study
Science.gov (United States)
Iwase, Hiroya; Tanaka, Muhei; Kobayashi, Yukiko; Wada, Sayori; Kuwahata, Masashi; Kido, Yasuhiro; Hamaguchi, Masahide; Asano, Mai; Yamazaki, Masahiro; Hasegawa, Goji; Nakamura, Naoto; Fukui, Michiaki
2015-01-01
Aims/Introduction A low-carbohydrate diet based on animal sources is associated with higher all-cause mortality, whereas a vegetable-based low-carbohydrate diet is associated with lower cardiovascular disease mortality. It has been suggested that acid/base imbalance might play an important role in some cardiometabolic abnormalities. The aims of the present study were to evaluate whether carbohydrate intake is associated with quality of dietary protein and acid load, and whether these are related to metabolic syndrome in patients with type 2 diabetes. Materials and Methods The present cross-sectional study involved 149 patients with type 2 diabetes. Dietary intake was assessed using a validated self-administered diet history questionnaire. Dietary acid load was assessed by potential renal acid load and net endogenous acid production. Results Mean daily total energy intake, carbohydrate intake, animal protein intake and vegetable protein intake were 1821.5 kcal, 248.8 g, 36.1 g and 31.1 g, respectively. Carbohydrate energy/total energy was negatively correlated with animal protein energy/total energy, potential renal acid load or net endogenous acid production score, and was positively correlated with vegetable protein energy/total energy. Logistic regression analyses showed that the subgroup of patients with a lower vegetable protein energy/total energy or higher potential renal acid load or net endogenous acid production score was significantly associated with the prevalence of metabolic syndrome. Conclusions The present study showed that carbohydrate intake was associated with the quality of dietary protein and dietary acid load. Furthermore, decreased vegetable protein intake and increased dietary acid load were associated with the prevalence of metabolic syndrome.
13. The classification, mapping and description of the vegetation of the Rooipoort Nature Reserve, Northern Cape, South Africa
Scientific Electronic Library Online (English)
Hugo, Bezuidenhout.
Full Text Available The need for a scientifically-based wildlife management plan and for more knowledge on vegetation led to an investigation into the plant ecology of the Rooipoort Nature Reserve. The main aim of this study was therefore to classify, describe and map the vegetation of the reserve. The floristic data w [...] ere analysed according to the Braun-Blanquet procedure using the BBPC suite. The data analysis resulted in the identification of 15 communities that can be grouped into ten major community types. This resulted in five ecology-based management units, which could assist with the compilation of an ecologically sound management plan for the reserve in order to achieve sustainable utilisation of the natural resources. The Rooipoort Nature Reserve is one of the oldest and largest private nature reserves in South Africa and as such deserves to be conserved and protected. The riverine and pan vegetation communities are considered to be endangered and are in need of special conservation and protection. CONSERVATION IMPLICATION: The results suggest five management units, which will assist in the compilation of an ecologically sound management plan for the RNR, in order to allow sustainable utilization of natural resources.
14. Environmental Impact of Flooding in the Main (Smallwood) Reservoir of the Churchill Falls Power Plant, Labrador, Canada. I. Background and Descriptions of Flooded Conditions Related to Vegetation and Land Cover Types
OpenAIRE
Bruce A. Roberts; Denes Bajzak
2011-01-01
This paper, the first in a series provides the background of the project, reports on the early phases of construction with the descriptions of the pre and post flooded conditions related to vegetation and land cover types surrounding the reservoir. Currently there are plans to develop the so called “Lower Churchill Area” by establishing new power plants at Gull Island and at Muskrat Falls with associated reservoirs. These new plants would use the discharged water of the plant from Churchill F...
15. Studying the effect of elevation and edaphic variables on vegetation composition in Khezrabad rangelands using principal component analysis (PCA
Directory of Open Access Journals (Sweden)
2009-11-01
Full Text Available A major scientific challenge in plant ecology is to identify and quantify the strength of environmental factors that are responsible for the distribution and abundance of plant species within and among ecosystems. Hence, this study is focused on relation between plant communities and environmental variables in Khezrabad region of Iran. Based on field surveys, eight vegetation types including Artemisia sieberi-Acantholimon erinaceum, Artemisia sieberi-Hertia angustifolia, Artemisia sieberi-Launea acanthodes, Artemisia sieberi-Salsola tomentosa, Artemisia sieberi-Zygophyllum atriplicoides, Artemisia aucheri-Astrgalus albispinus, Artemisia sieberi-Fortuynia bungei, Haloxylon aphyllum were identified. With respecting to the present variance between vegetation and environmental factors, four samples were established in each vegetation type in 0–30 cm depth. The studied soil variables affecting plant communities were texture, EC, pH, Na+, k+, Cl-, Ca2+, Mg2+, SP, O.M, CaCO3, HCO3 - and CEC. Among the topographic conditions, elevation was recorded in sampling regions as well. Data matrix of environmental factors and vegetation type was made using the windows (ver. 4.17 of PC-ORD. Results according to PCA showed that in the study area, among different environmental factors, the distribution of vegetation types was most strongly correlated with some agents such as soil texture, salinity and sodicity. In fact, soil texture controls distribution of plant species by affecting moisture availability, ventilation and distribution of plant roots. Beside, soil salinity and sodicity because of habitat condition, plant ecological needs and tolerance range can have negative affect on plant diversity. In addition, results indicated that increasing of elevation had negative effect on plant distribution. However, soil characteristics have more influence on vegetation separation than to the elevation in this study.
16. Ecological Characteristics of a Gonystylus bancanus-rich Area in Pekan Forest Reserve, Pahang, Malaysia
OpenAIRE
Hamzah, Khali Aziz; Ismail, Parlan; Kassim, Abd Rahman; Hassan, Che Hashim; Akeng, Grippin; Said, Nizam Mohd
2009-01-01
Tropical peat swamp forest (PSF) is a unique wetland ecosystem with distinct vegetation types. Due to the waterlogged environment, the stand characteristics in this ecosystem are different from those of other inland forests. This paper highlights stand characteristics of a PSF based on our investigation of a 1 ha ecological plot established in a Virgin Jungle Reserve (VJR) at Compartment 100, Pekan Forest Reserve, Pahang, Malaysia. This site is considered a Gonystylus bancanus-rich area. From...
17. Applications of ERTS data to coastal wetland ecology with special reference to plant community mapping and typing and impact of man. [Delaware, Maryland, Virginia, South Carolina, and Georgia
Science.gov (United States)
Anderson, R. R.; Carter, V. P.; Mcginness, J.
1974-01-01
Complete seasonal ERTS-1 coverage of Atlantic coastal wetlands from Delaware Bay to Georgia provides a basis for assessment of temporal data for wetland mapping, evaluation, and monitoring. Both MSS imagery and digital data have proved useful for gross wetland species delineation and determination of the upper wetland boundary. Tidal effects and (band to band or seasonal) spectral reflectance differences make it possible to type vegetatively coastal wetlands in salinity related categories. Management areas, spoil disposal sites, drainage ditches, lagoon-type developments and highway construction can be detected indicating a monitoring potential for the future. A northern test site (Maryland-Virginia) and a southern test site (Georgia-South Carolina), representing a range of coastal marshes from saline to fresh, were chosen for intensive study. Wetland maps were produced at various scales using both ERTS imagery (bands 5 and 7) and digital data (bands 4, 5 and 7).
18. Bacteriophage Ecology in Commercial Sauerkraut Fermentations†
OpenAIRE
Lu, Z.; Breidt, F; Plengvidhya, V.; Fleming, H P
2003-01-01
Knowledge of bacteriophage ecology in vegetable fermentations is essential for developing phage control strategies for consistent and high quality of fermented vegetable products. The ecology of phages infecting lactic acid bacteria (LAB) in commercial sauerkraut fermentations was investigated. Brine samples were taken from four commercial sauerkraut fermentation tanks over a 60- or 100-day period in 2000 and 2001. A total of 171 phage isolates, including at least 26 distinct phages, were obt...
19. [Tourism function zoning of Jinyintan Grassland Scenic Area in Qinghai Province based on ecological sensitivity analysis].
Science.gov (United States)
Zhong, Lin-sheng; Tang, Cheng-cai; Guo, Hua
2010-07-01
Based on the statistical data of natural ecology and social economy in Jinyintan Grassland Scenic Area in Qinghai Province in 2008, an evaluation index system for the ecological sensitivity of this area was established from the aspects of protected area rank, vegetation type, slope, and land use type. The ecological sensitivity of the sub-areas with higher tourism value and ecological function in the area was evaluated, and the tourism function zoning of these sub-areas was made by the technology of GIS and according to the analysis of eco-environmental characteristics and ecological sensitivity of each sensitive sub-area. It was suggested that the Jinyintan Grassland Scenic Area could be divided into three ecological sensitivity sub-areas (high, moderate, and low), three tourism functional sub-areas (restricted development ecotourism, moderate development ecotourism, and mass tourism), and six tourism functional sub-areas (wetland protection, primitive ecological sightseeing, agriculture and pasture tourism, grassland tourism, town tourism, and rural tourism). PMID:20879542
20. Vegetation state in the alienation zone after the Chernobyl accident
International Nuclear Information System (INIS)
Vegetation state within the alienation zone on the territory of formed state farm 'Savichi' of the Bragin region was studied. 9 agroecosystem associations of the Braun-Blanguet system were selected. Their ecological, biological and economic characteristics are given. The research has shown that the content of Sr 90 in vegetative mass of most agroecosystem associations exceeded normative level. (authors)
1. Vegetation in the Gravettian Period – an Overview.
Czech Academy of Sciences Publication Activity Database
Pokorný, Petr
Brno : Academy of Sciences of the Czech Republic, Institute of Archaeology at Brno, 2009 - ( Šída , P.), s. 30-37 ISBN 978-80-86023-86-1. - (Dolnov?stonické studie. 17) Institutional research plan: CEZ:AV0Z80020508 Keywords : palaeolithic * vegetation * palaeoecology Subject RIV: EH - Ecology, Behaviour
2. New insights into vegetation patterns and processes.
Czech Academy of Sciences Publication Activity Database
Öpik, M.; de Bello, Francesco; Price, J. N.; Fraser, L. H.
2014-01-01
Ro?. 201, ?. 2 (2014), s. 383-387. ISSN 1469-8137 R&D Projects: GA ?R GAP505/12/1296 Institutional support: RVO:67985939 Keywords : community * interaction * vegetation patterns Subject RIV: EH - Ecology, Behaviour Impact factor: 6.373, year: 2013
3. An interdisciplinary analysis of multispectral satellite data for selected cover types in the Colorado Mountains, using automatic data processing techniques. [hydrology, ecology, geology, vegetation, and mineral deposits
Science.gov (United States)
Hoffer, R. M. (principal investigator)
1974-01-01
The author has identified the following significant results. Documentation is presented of the capability of the middle infrared portion of the electromagnetic spectrum to spectrally differentiate clouds from snow. Other portions of the spectrum cannot provide this capability.
4. Microbial ecology of watery kimchi.
Science.gov (United States)
Kyung, Kyu Hang; Medina Pradas, Eduardo; Kim, Song Gun; Lee, Yong Jae; Kim, Kyong Ho; Choi, Jin Joo; Cho, Joo Hyong; Chung, Chang Ho; Barrangou, Rodolphe; Breidt, Frederick
2015-05-01
The biochemistry and microbial ecology of 2 similar types of watery (mul) kimchi, containing sliced and unsliced radish and vegetables (nabak and dongchimi, respectively), were investigated. Samples from kimchi were fermented at 4, 10, and 20 °C were analyzed by plating on differential and selective media, high-performance liquid chromatography, and high-throughput DNA sequencing of 16S rDNA. Nabak kimchi showed similar trends as dongchimi, with increasing lactic and acetic acids and decreasing pH for each temperature, but differences in microbiota were apparent. Interestingly, bacteria from the Proteobacterium phylum, including Enterobacteriaceae, decreased more rapidly during fermentation at 4 °C in nabak cabbage fermentations compared with dongchimi. Although changes for Proteobacterium and Enterobacteriaceae populations were similar during fermentation at 10 and 20 °C, the homolactic stage of fermentation did not develop for the 4 and 10 °C samples of both nabak and dongchimi during the experiment. These data show the differences in biochemistry and microbial ecology that can result from preparation method and fermentation conditions of the kimchi, which may impact safety (Enterobacteriaceae populations may include pathogenic bacteria) and quality (homolactic fermentation can be undesirable, if too much acid is produced) of the product. In addition, the data also illustrate the need for improved methods for identifying and differentiating closely related lactic acid bacteria species using high-throughput sequencing methods. PMID:25847522
5. Ecological restoration and soil improvement performance of the seabuckthorn flexible dam in the Pisha Sandstone area of Northwestern China
Directory of Open Access Journals (Sweden)
F. S. Yang
2014-09-01
Full Text Available Soil erosion of the Pisha Sandstone area of Loess Plateau is extremely severe in China. The Pisha Sandstone is very hard when it is dry, while it is very frail when wet. The seabuckthorn flexible dam (SFD, a type of ecological engineering, was proposed to control soil erosion and meliorate soil within the Pisha Sandstone area. To assess its effectiveness and the ecological restoration and soil improvement performance, a field experiment was conducted in this area. We found the strong sediment retention capacity of the SFD is the basis of using it to restore the ecosystem. We compared some certain ecological factors and soil quality between a gully with the SFD and a gully without the SFD, including soil moisture, soil organic matter (SOM, soil nutrients (including Ammonia Nitrogen, available phosphorus and Potassium, vegetation coverage and biodiversity. The results showed that the SFD exhibits excellent performance for ecological restoration and soil improvement of this area. The results are as follows: (i by the sediment retention action, the deposition commonly occurred in the SFD gully, and the deposition patterns are obviously different from upper to lower gully, (ii more surprisingly, unlike trees or other shrubs, the seabuckthorn has good horizontal extending capacity by its root system, (iii soil moisture, SOM, soil nutrients, vegetation coverage and biodiversity in the vegetated gully with the SFD are all markedly increased. The results showed the SFD is both effective and novel biological measure for ecological restoration and soil improvement within the Pisha Sandstone area.
6. Characterization of subarctic vegetation using ground based remote sensing methods
Science.gov (United States)
Finnell, D.; Garnello, A.; Palace, M. W.; Sullivan, F.; Herrick, C.; Anderson, S. M.; Crill, P. M.; Varner, R. K.
2014-12-01
Stordalen mire is located at 68°21'N and 19°02'E in the Swedish subarctic. Climate monitoring has revealed a warming trend spanning the past 150 years affecting the mires ability to hold stable palsa/hummock mounds. The micro-topography of the landscape has begun to degrade into thaw ponds changing the vegetation cover from ombrothrophic to minerotrophic. Hummocks are ecologically important due to their ability to act as a carbon sinks. Thaw ponds and sphagnum rich transitional zones have been documented as sources of atmospheric CH4. An objective of this project is to determine if a high resolution three band camera (RGB) and a RGNIR camera could detect differences in vegetation over five different site types. Species composition was collected for 50 plots with ten repetitions for each site type: palsa/hummock, tall shrub, semi-wet, tall graminoid, and wet. Sites were differentiated based on dominating species and features consisting of open water presence, sphagnum spp. cover, graminoid spp. cover, or the presence of dry raised plateaus/mounds. A pole based camera mount was used to collect images at a height of ~2.44m from the ground. The images were cropped in post-processing to fit a one-square meter quadrat. Texture analysis was performed on all images, including entropy, lacunarity, and angular second momentum. Preliminary results suggested that site type influences the number of species present. The p-values for the ability to predict site type using a t-test range from mire site types. Future work will involve scaling up from the 50 plots through the use of data collected from two unmanned aerial systems (UAS), as well as WorldView-2 satellite imagery collected during the years 2012-2014. Identification of methane flux regions will later be analyzed based on vegetation coverage to aid classification of increased emission zones within the mire.
7. Is New Zealand vegetation really 'problematic'? Dansereau's puzzles revisited.
Science.gov (United States)
Wilson, J Bastow; Lee, William G
2012-05-01
Over four decades ago, Pierre Dansereau, the noted North American ecologist, proposed six features of New Zealand vegetation as being problematic or unusual in a global context. We examine his propositions in the light of current ecological knowledge to determine whether or not these can still be considered unusual characteristics of New Zealand vegetation. (1) 'Climatic change is still progressing' resulting in disequilibrium between species' distributions and the present climate. New data and methods of analysis now available have removed the impression that Dansereau gained of imprecise zonation, unclear vegetation/climate relations and missing vegetation types. Communities cited as having regeneration failure can now be seen as even-aged stands that developed after major disturbance, although there are other, also non-climatic, explanations. However, the cause of the Westland 'Nothofagus gap' has become more, rather than less, controversial. (2) 'Continuity of community composition defies classification' and 'Very few New Zealand associations have faithful species' are correct observations, but perhaps equally true of vegetation elsewhere. Dansereau's assertion of low species richness in New Zealand is not supported by the comparative data available. (3) 'Lack of intolerant [i.e. mid-seral] trees …' is not evident with newer information. The order of species in succession, seen as unclear by Dansereau, has been determined by a range of approaches, largely confirming each other. (4) 'Discrepancies of form and function …' in divaricate shrubs and widespread heteroblasty are still controversial, with many more explanations. Several abiotic explanations have failed to stand up to investigation. Explanations in terms of herbivory have been well supported, although the extinction of the large avian herbivores makes certainty impossible. (5) 'Incidence of hybridization …' remains problematic. We do not know whether the incidence is unusually high, as Dansereau alleged, but the limited comparative data available suggest not. (6) The 'overwhelming … competing power of exotics' is strongly context dependent. They are prominent in many non-forest habitats. It seems that they are drivers of the vegetation change in some habitats, yet passengers after disturbance in others. Invasions can be slow, and may still be very incomplete in some ecosystem types. Whether exotics will eventually take over in most communities, or whether the native species will 'laugh them to scorn' as Cockayne suggested, only time will tell. In conclusion, some aspects of New Zealand's vegetation seem less unusual with increased knowledge, but others remain 'problems'. PMID:21929714
8. Vegetation communities associated with the 100-Area and 200-Area facilities on the Hanford Site
International Nuclear Information System (INIS)
The Hanford Site, Benton County, Washington, lies within the broad semi-arid shrub-steppe vegetation zone of the Columbia Basin. Thirteen different habitat types on the Hanford Site have been mapped in Habitat Types on the Hanford Site: Wildlife and Plant Species of Concern (Downs et al. 1993). In a broad sense, this classification is correct. On a smaller scale, however, finer delineations are possible. This study was conducted to determine the plant communities and estimate vegetation cover in and directly adjacent to the 100 and 200 Areas, primarily in relation to waste sites, as part of a comprehensive ecological study for the Compensation Environmental Response, Compensation, and Liability Act (CERCLA) characterization of the 100 and 200 Areas. During the summer of 1993, field surveys were conducted and a map of vegetation communities in each area, including dominant species associations, was produced. The field surveys consisted of qualitative community delineations. The community delineations described were made by field reconnaissance and are qualitative in nature. The delineations were made by visually determining the dominant plant species or vegetation types and were based on the species most apparent at the time of inspection. Additionally, 38 transects were run in these plant communities to try to obtain a more accurate representation of the community. Because habitat disturbances from construction/operations activities continue to occur in these areas, users of this information should be cautious in applying these maps without a current ground survey. This work will complement large-scale habitat maps of the Hanford Site
9. Vegetation communities associated with the 100-Area and 200-Area facilities on the Hanford Site
Energy Technology Data Exchange (ETDEWEB)
Stegen, J.A.
1994-01-17
The Hanford Site, Benton County, Washington, lies within the broad semi-arid shrub-steppe vegetation zone of the Columbia Basin. Thirteen different habitat types on the Hanford Site have been mapped in Habitat Types on the Hanford Site: Wildlife and Plant Species of Concern (Downs et al. 1993). In a broad sense, this classification is correct. On a smaller scale, however, finer delineations are possible. This study was conducted to determine the plant communities and estimate vegetation cover in and directly adjacent to the 100 and 200 Areas, primarily in relation to waste sites, as part of a comprehensive ecological study for the Compensation Environmental Response, Compensation, and Liability Act (CERCLA) characterization of the 100 and 200 Areas. During the summer of 1993, field surveys were conducted and a map of vegetation communities in each area, including dominant species associations, was produced. The field surveys consisted of qualitative community delineations. The community delineations described were made by field reconnaissance and are qualitative in nature. The delineations were made by visually determining the dominant plant species or vegetation types and were based on the species most apparent at the time of inspection. Additionally, 38 transects were run in these plant communities to try to obtain a more accurate representation of the community. Because habitat disturbances from construction/operations activities continue to occur in these areas, users of this information should be cautious in applying these maps without a current ground survey. This work will complement large-scale habitat maps of the Hanford Site.
Science.gov (United States)
McGarity, Augustus C., III; Maulding, Wanda
2007-01-01
This article discusses how all four facets of administrative ecology help dispel the claims about the "impossibility" of the superintendency. These are personal ecology, professional ecology, organizational ecology, and community ecology. Using today's superintendency as an administrative platform, current literature describes a preponderance of…
11. Social-ecological feedbacks between climate, reindeer and people - contributions to climate change adaptation?
Science.gov (United States)
Käyhkö, Jukka; Horstkotte, Tim; Kivinen, Sonja; Johansen, Bernt
2015-04-01
The circumpolar tundra is experiencing significant transformations as a consequence of climate change. The anticipated changes include greening of the tundra due to a latitudinal and altitudinal progression of the tree line and range expansion of shrubs. In Northern Fennoscandia, reindeer husbandry by the indigenous Sámi people depends on large, seasonally variable grazing grounds, including the tundra. We demonstrate relationships between different vegetation types and climate conditions in Northern Fennoscandia. A generalized, seamless vegetation type map with 100 m grid, based on Landsat TM/ETM+ satellite images and various ancillary data, allows examination of vegetation types in relation to current climate conditions (1950-2000). Downscaled GCMs with different RCPs for 2050 and 2070 allow estimating future vegetation changes. Recently, the potential of herbivores has been recognized in slowing down this regime shift of vegetation composition with its feedbacks e.g. on the atmospheric energy balance, biodiversity and local livelihoods that depend on the tundra ecosystem. However, ecology alone is not the answer. We need comprehensive scenarios for adaptive ecosystem management for this social-ecological system to slow down the unfavourable impacts of climate change and excessive grazing pressure by reindeer in space and time, as well as across country borders. Possible adaptations could encourage the design of new institutional structures, and thus contest the legal background governing reindeer husbandry in the Nordic countries today. Designing such policy options for socially desirable and ecologically reasonable decision making, as well as navigating trade-offs inherent in flexible grazing patterns, require careful scenario analysis and acceptance by a variety of land users. A clear understanding of which values should be prioritized in relation to what ecosystem dynamics over what time scales is essential.
12. El papel de las unidades de manejo ambiental en la conservación de los tipos de vegetación de Coahuila / The environmental management units in the conservation of vegetation types in Coahuila state
Scientific Electronic Library Online (English)
César, Cantú Ayala; Fernando, González Saldivar; Patricia, Koleff Osorio; José, Uvalle Sauceda; José G., Marmolejo Monsivais; Jorge, García Hernández; Laura, Rentería Arrieta; Jonás, Delgadillo Villalobos; Cynthia, Resendiz Infante; Edgardo, Ortíz Hernández.
2011-08-01
Full Text Available Se determinó con el método de análisis de vacíos y omisiones de conservación (GAP), cómo contribuyen las 289 unidades de manejo para la conservación de la vida silvestre (UMA) de Coahuila a la conservación de los tipos de vegetación natural. Mediante un análisis de componentes principales se definió [...] la relación entre los tipos de vegetación de Coahuila, respecto a su representatividad en áreas protegidas (AP). Las UMA en el estado cubren 1,546,778 ha, de ellas 72.6% se localizan, principalmente, en sitios con cuatro tipos de vegetación primaria, que en orden de cobertura son: matorral desértico rosetófilo, matorral espinoso tamaulipeco, matorral desértico micrófilo y pastizal natural. Si se considera a las UMA como elementos equivalentes a las AP en la conservación de la biodiversidad, éstas cubrirían todos los tipos de vegetación que son omisiones de conservación en la red de AP, con excepción de la vegetación gipsófila y la halófila. Sin embargo, no incluirían los cuatro tipos de vegetación, que son a la vez vacíos de conservación en la actual red de AP, las cuales en suma sólo representan 12,514 ha. Las UMA comprenden más del 25% de la extensión del matorral espinoso tamaulipeco y 4 mezquital primarios de Coahuila, actualmente sub-representados en la red de AP de la entidad por lo que éstas, podrían contribuir a la conservación de la biodiversidad, si se manejaran sustentablemente, y de la cobertura natural del suelo. Abstract in english In order to know the way in which the 289 units for management and conservation of wildlife (UMA, according to its initials in Spanish) contribute to the conservation of natural vegetation types of Coahuila, the gap method was used. By the Principal Component Analysis was determined the relationship [...] of the vegetation types of the state in regard to the representativeness in protected areas (PA). The local UMAs cover 1, 546, 778 ha; 72 % of them are found, mainly, in places where the four types of primary vegetation are present, which, according to their extent, would be as follows: desert microphilous scrub, desert rosetophilous scrub, tamaulipean thorn scrub and natural grassland. If UMA would be considered equivalent to PA for biodiversity conservation they would cover five vegetation types which are gaps in current protected areas; however, two plant communities: halophilous vegetation and gypsophilous vegetation would be represented in PA below the reach of the national protected average of Mexico (12%). Moreover, four vegetation types, which represent only 12,514 ha, are not represented neither in PA nor in UMA. Coahuila's UMAs cover 25% of its tamaulipean thorn scrub and mesquite land extension in primary condition, which are currently under-represented in state PA network. That means, UMA can contribute to biodiversity conservation if they are sustainably managed, protecting natural land cover.
13. Monitoring Environmental Impact in the Upper Sonoran Lifestyle: A New Tool for Rapid Ecological Assessment
Science.gov (United States)
Allen, Casey D.
2009-02-01
Characterized by expensive housing, high socioeconomic status, and topographic relief, Upper Sonoran Lifestyle communities are found primarily along the Wildland-Urban Interface (WUI) in the Phoenix, Arizona metro area. Communities like these sprawl into the wildlands in the United States Southwest, creating a distinct urban fringe. This article, through locational comparison, introduces and evaluates a new field assessment tool for monitoring anthropogenic impact on soil-vegetation interactions along the well-maintained multi-use recreational trails in Upper Sonoran Lifestyle region. Comparing data from randomly selected transects along other multi-use trails with data from a control site revealed three key indicators of anthropogenic disturbances on soil-vegetation interactions: soil disturbance, vegetation disturbance, and vegetation density. Soil and vegetation disturbance displayed an average distance decay exponent factor of -0.60, while vegetation density displayed a reverse decay average of 0.60. Other important indicators of disturbance included vegetation type, biological soil crusts, and soil bulk density. The predictive ability of this new field tool enhances its applicability, offering a powerful rapid ecological assessment method for monitoring long-term anthropogenic impact in the Upper Sonoran Lifestyle, and other sprawling cities along the WUI.
14. Vegetation - radiation: Relationships in subalpine zones. Strahlung und Vegetation
Energy Technology Data Exchange (ETDEWEB)
Kronfuss, H.; Stern, R.
1978-01-01
15. Efectos del cambio climático en la diversidad vegetal del corredor de conservación comunitaria Reserva Ecológica El Ángel- Bosque Protector Golondrinas en el norte del Ecuador / The effects of climate change on vegetative diversity in the El Angel Ecological Reserve-Golondrinas Protected Forest community conservation corridor in northern Ecuador
Scientific Electronic Library Online (English)
2009-12-01
Full Text Available Para estimar el impacto del cambio climático en el corredor de conservación comunitaria Reserva Ecológica El Ángel - Bosque Protector Golondrinas en el norte del Ecuador se utilizó modelos de distribución potencial generados con MARS de 413 especies vegetales, usando 19 variables bioclimáticas de Wo [...] rldclim con el clima actual y para el 2080 estas mismas variables fueron estimadas de acuerdo al modelo HadCM3-A2. En base a esta información se generaron mapas de riqueza tanto para el presente como para el 2080. Para el área del corredor se han identificado zonas donde se estima que haya cambios de riqueza y donde potencialmente las especies podrían colonizar nuevas áreas o donde se extinguirán. Esto permite determinar el grado de perturbación que sufrirán los ecosistemas por efecto del cambio climático. La tendencia general de las especies estudiadas muestra que colonizarán altitudes más elevadas, cambiando la estructura de los ecosistemas naturales actuales. Toda esta información muestra que para afrontar potenciales impactos en la flora de los ecosistemas de montaña es necesario formar corredores que conecten altitudinalmente áreas naturales protegidas, que permitan la migración de especies y por ende la conservación de la biodiversidad. Abstract in english In order to estimate the impact of climate change on the El Angel Ecological Reserve - Golondrinas Protected Forest community conservation corridor, potential distribution models generated using MARS of 413 vegetative species were applied using 19 Worldclim bioclimatic variables for current climate, [...] and for the year 2080, these same variables were estimated according to the HadCM3-A2 general circulation model. Based on this information, richness maps were developed for the present and for 2080. In the area of the corridor, zones were identified where changes in richness were predicted, where species could potentially colonize, or where species could become extinct. This allows the determination of the level of disturbance that the ecosystems will suffer with climate change. The general tendency of the species studied shows that they will colonize higher altitudes thus changing the structures of current natural ecosystems. All of this information demonstrates that to deal with potential impacts on the flora of mountain ecosystems it will be necessary to create corridors that will connect protected areas located at differing altitudes and thus permit species migration that will in turn conserve biodiversity.
16. Mapping ecological states in a complex environment
Science.gov (United States)
Steele, C. M.; Bestelmeyer, B.; Burkett, L. M.; Ayers, E.; Romig, K.; Slaughter, A.
2013-12-01
The vegetation of northern Chihuahuan Desert rangelands is sparse, heterogeneous and for most of the year, consists of a large proportion of non-photosynthetic material. The soils in this area are spectrally bright and variable in their reflectance properties. Both factors provide challenges to the application of remote sensing for estimating canopy variables (e.g., leaf area index, biomass, percentage canopy cover, primary production). Additionally, with reference to current paradigms of rangeland health assessment, remotely-sensed estimates of canopy variables have limited practical use to the rangeland manager if they are not placed in the context of ecological site and ecological state. To address these challenges, we created a multifactor classification system based on the USDA-NRCS ecological site schema and associated state-and-transition models to map ecological states on desert rangelands in southern New Mexico. Applying this system using per-pixel image processing techniques and multispectral, remotely sensed imagery raised other challenges. Per-pixel image classification relies upon the spectral information in each pixel alone, there is no reference to the spatial context of the pixel and its relationship with its neighbors. Ecological state classes may have direct relevance to managers but the non-unique spectral properties of different ecological state classes in our study area means that per-pixel classification of multispectral data performs poorly in discriminating between different ecological states. We found that image interpreters who are familiar with the landscape and its associated ecological site descriptions perform better than per-pixel classification techniques in assigning ecological states. However, two important issues affect manual classification methods: subjectivity of interpretation and reproducibility of results. An alternative to per-pixel classification and manual interpretation is object-based image analysis. Object-based image analysis provides a platform for classification that more closely resembles human recognition of objects within a remotely sensed image. The analysis presented here compares multiple thematic maps created for test locations on the USDA-ARS Jornada Experimental Range ranch. Three study sites in different pastures, each 300 ha in size, were selected for comparison on the basis of their ecological site type (';Clayey', ';Sandy' and a combination of both) and the degree of complexity of vegetation cover. Thematic maps were produced for each study site using (i) manual interpretation of digital aerial photography (by five independent interpreters); (ii) object-oriented, decision-tree classification of fine and moderate spatial resolution imagery (Quickbird; Landsat Thematic Mapper) and (iii) ground survey. To identify areas of uncertainty, we compared agreement in location, areal extent and class assignation between 5 independently produced, manually-digitized ecological state maps and with the map created from ground survey. Location, areal extent and class assignation of the map produced by object-oriented classification was also assessed with reference to the ground survey map.
17. Comparing heavy metals accumulation potential in natural vegetation and soil adjoining wastewater canal
International Nuclear Information System (INIS)
Heavy metal (HM) pollution of waters, soils and vegetation is a major ecological problem that needs to be investigated. The present study involved the collection of soil samples and natural vegetations (Tribilas terristris, Lepia nodiflora, Amaranthus viridis, Heliotropium euoropeum, Coronopis didymus, Cynodon ductylon, Chenopodium murale and Eclipta alba) from the vicinity of wastewater canal and subsequent analysis for their HM concentrations. Results showed that HM concentrations varied within the species of vegetation and type of metal analyzed. The order of vegetation for metal concentrations was A. viridis > E. alba > H. euoropeum > L. nodiflora > C. murale > C. didymus > C. ductylon > T. terristris. Metals prevailed in plants in the decreasing order of Fe > Mn > Zn > Pb > Cr > Cu > Cd, irrespective of the vegetation. Metal prevalence in soils was in the order of Fe > Mn > Cd > Cr > Pb > Zn > Cu. Samples near canal were found with higher level of Mn, Pb and Zn as compared to soil away from canal water. Distant sampling gave higher accumulation of Cd, Cr, Cu and Fe as compared to the soil nearby wastewater. The analyzed species of HM in the soils and plants may indicate the variability of their composition in wastewater. (author)
18. Is grazing exclusion effective in restoring vegetation in degraded alpine grasslands in Tibet, China?
Directory of Open Access Journals (Sweden)
Yan Yan
2015-06-01
Full Text Available Overgrazing is considered one of the key disturbance factors that results in alpine grassland degradation in Tibet. Grazing exclusion by fencing has been widely used as an approach to restore degraded grasslands in Tibet since 2004. Is the grazing exclusion management strategy effective for the vegetation restoration of degraded alpine grasslands? Three alpine grassland types were selected in Tibet to investigate the effect of grazing exclusion on plant community structure and biomass. Our results showed that species biodiversity indicators, including the Pielou evenness index, the Shannon–Wiener diversity index, and the Simpson dominance index, did not significantly change under grazing exclusion conditions. In contrast, the total vegetation cover, the mean vegetation height of the community, and the aboveground biomass were significantly higher in the grazing exclusion grasslands than in the free grazed grasslands. These results indicated that grazing exclusion is an effective measure for maintaining community stability and improving aboveground vegetation growth in alpine grasslands. However, the statistical analysis showed that the growing season precipitation (GSP plays a more important role than grazing exclusion in which influence on vegetation in alpine grasslands. In addition, because the results of the present study come from short term (6–8 years grazing exclusion, it is still uncertain whether these improvements will be continuable if grazing exclusion is continuously implemented. Therefore, the assessments of the ecological effects of the grazing exclusion management strategy on degraded alpine grasslands in Tibet still need long term continued research.
19. Is grazing exclusion effective in restoring vegetation in degraded alpine grasslands in Tibet, China?
Science.gov (United States)
Yan, Yan
2015-01-01
Overgrazing is considered one of the key disturbance factors that results in alpine grassland degradation in Tibet. Grazing exclusion by fencing has been widely used as an approach to restore degraded grasslands in Tibet since 2004. Is the grazing exclusion management strategy effective for the vegetation restoration of degraded alpine grasslands? Three alpine grassland types were selected in Tibet to investigate the effect of grazing exclusion on plant community structure and biomass. Our results showed that species biodiversity indicators, including the Pielou evenness index, the Shannon–Wiener diversity index, and the Simpson dominance index, did not significantly change under grazing exclusion conditions. In contrast, the total vegetation cover, the mean vegetation height of the community, and the aboveground biomass were significantly higher in the grazing exclusion grasslands than in the free grazed grasslands. These results indicated that grazing exclusion is an effective measure for maintaining community stability and improving aboveground vegetation growth in alpine grasslands. However, the statistical analysis showed that the growing season precipitation (GSP) plays a more important role than grazing exclusion in which influence on vegetation in alpine grasslands. In addition, because the results of the present study come from short term (6–8 years) grazing exclusion, it is still uncertain whether these improvements will be continuable if grazing exclusion is continuously implemented. Therefore, the assessments of the ecological effects of the grazing exclusion management strategy on degraded alpine grasslands in Tibet still need long term continued research.
20. An Evaluation of the Romanian Fruits and Vegetables Producers Access to Different Types of Common Agricultural Policy Instruments. Is there Any Real Consistency with the Policy Objectives?
Directory of Open Access Journals (Sweden)
Nicu MARCU
2015-04-01
Full Text Available Fruits and vegetables sectors are considered to be strategic in the European Union due to their contribution to a better human health. Among others positive effects, their intake increase reduce mortality and obesity, assuring in the same time harmonised development for young children. The present study thus focused to reveal the consistency of the measure implemented in the Common Agricultural Policy to support fruits and vegetables production in Romania in liaison with the policy objectives. The country is one of the main ten important European producers of horticultural products in terms of production volumes and acreage. Results showed that over the last seven years (2007-2014, the sectorial production drawbacks have not been ameliorated very much. Both sectors are dominated by small-size farms that can produce only seasonally and mainly for short-market chains. In the same time, the greenhouses area shrink to levels that made the country extremely dependent to imports especially for tomatoes. The analysis of the pillar one payments schemes revealed that the fruits and vegetables producers could have access to only one payment that was half from European averages. Moreover, almost half of the producers had low sizes that left them outside the eligible criteria. The measures designed for the second pillar also penalized producers through the selection criteria. These results showed that for Romania there was not a real consistency between the actual policy measures and the objectives assumed by policy makers. The future measures (2014-2020 seem to correct these negative findings being better tailored to the situation of the local fruits and vegetables producers.
1. SFRSF: Landscape Synthesis and Ecological Modeling
Science.gov (United States)
This South Florida Restoration Science Forum (SFRSF) site explores how to understand, describe, and predict ecological changes at the landscape and regional levels. Issues discussed include the effects of landscape hydrology on specific animal populations, predicting ecological responses to landscape management, understanding changes in the landscape by studying vegetation patterns, and the Cape Sable Seaside Sparrow's importance to understanding ecological changes. Links are provided for further information.
2. Ecological recovery in an Arctic delta following widespread saline incursion.
Science.gov (United States)
Lantz, Trevor C; Kokelj, Steve V; Fraser, Robert H
2015-01-01
Arctic ecosystems are vulnerable to the combined effects of climate change and a range of other anthropogenic perturbations. Predicting the cumulative impact of these stressors requires an improved understanding of the factors affecting ecological resilience. In September of 1999, a severe storm surge in the Mackenzie Delta flooded alluvial surfaces up to 30 km inland from the coast with saline waters, driving environmental impacts unprecedented in the last millennium. In this study we combined field monitoring of permanent sampling plots with an analysis of the Landsat archive (1986-2011) to explore the factors affecting the recovery of ecosystems to this disturbance. Soil salinization following the 1999 storm caused the abrupt dieback of more than 30,000 ha of tundra vegetation. Vegetation cover and soil chemistry show that recovery is occurring, but the rate and spatial extent are strongly dependent on vegetation type, with graminoid- and upright shrub-dominated areas showing recovery after a decade, but dwarf shrub tundra exhibiting little to no recovery over this period. Our analyses suggest that recovery from salinization has been strongly influenced by vegetation type and the frequency of freshwater flooding following the storm. With increased ocean storm activity, rising sea levels, and reduced sea ice cover, Arctic coastal ecosystems will be more likely to experience similar disturbances in the future, highlighting the importance of combining field sampling with regional-scale remote sensing in efforts to detect, understand, and anticipate environmental change. PMID:26255366
3. Ecological impact assessment
International Nuclear Information System (INIS)
Quantitative problems in accomplishing ecological impact assessment with particular reference to defining population effects are discussed with some comments on the two approaches most commonly used, e.g., the experimental and simulation models. Some alternatives are suggested because both methods will probably fail to detect real population effects mostly due to poor understanding of ecosystems or because of the limitations inherent in field census methods. Most judgments of ecological impact are not quantitatively defensible but are qualitative, subjective, or political in nature. An examination of aggregates of data from various nuclear power plant sites may be one way to obtain enough replication to judge ecological impact. Thus, currently available data from such studies as well as appropriate demographic, vegetation, census, and bibliographic material could offer an interesting challenge to computer professionals if such an undertaking were contemplated. Present research programs at PNL and computer involvement are described. Future possibilities and directions are discussed. (U.S.)
4. A minimal model of fire-vegetation feedbacks and disturbance stochasticity generates alternative stable states in grassland–shrubland–woodland systems
Science.gov (United States)
Batllori, Enric; Ackerly, David D.; Moritz, Max A.
2015-03-01
Altered disturbance regimes in the context of global change are likely to have profound consequences for ecosystems. Interactions between fire and vegetation are of particular interest, as fire is a major driver of vegetation change, and vegetation properties (e.g., amount, flammability) alter fire regimes. Mediterranean-type ecosystems (MTEs) constitute a paradigmatic example of temperate fire-prone vegetation. Although these ecosystems may be heavily impacted by global change, disturbance regime shifts and the implications of fire-vegetation feedbacks in the dynamics of such biomes are still poorly characterized. We developed a minimal modeling framework incorporating key aspects of fire ecology and successional processes to evaluate the relative influence of extrinsic and intrinsic factors on disturbance and vegetation dynamics in systems composed of grassland, shrubland, and woodland mosaics, which characterize many MTEs. In this theoretical investigation, we performed extensive simulations representing different background rates of vegetation succession and disturbance regime (fire frequency and severity) processes that reflect a broad range of MTE environmental conditions. Varying fire-vegetation feedbacks can lead to different critical points in underlying processes of disturbance and sudden shifts in the vegetation state of grassland–shrubland–woodland systems, despite gradual changes in ecosystem drivers as defined by the environment. Vegetation flammability and disturbance stochasticity effectively modify system behavior, determining its heterogeneity and the existence of alternative stable states in MTEs. Small variations in system flammability and fire recurrence induced by climate or vegetation changes may trigger sudden shifts in the state of such ecosystems. The existence of threshold dynamics, alternative stable states, and contrasting system responses to environmental change has broad implications for MTE management.
5. Vegetable of Slovene origin and consumers
OpenAIRE
Kokalj, Doris
2012-01-01
Production of vegetable is decreasing constantly in Slovenia. From health point of view locally produced food is more recommendable, because it contains fewer residues of pesticides, more vitamins and has high quality. In my dissertation I presented state of agriculture in Slovenia. Above all I was interested in state and production of vegetables. I described different types of production of vegetable, from conventional to biological dynamic. I was interested in rules, laws and regulation...
6. Probabilistic Evaluation of Anthropogenic Regulations In a Vegetated River Channel Using a Vegetation Dynamics Modeling
Science.gov (United States)
Miyamoto, Hitoshi
2015-04-01
Vegetation overgrowth in fluvial floodplains, gravel beds, and sand bars has been a serious engineering problem for riparian management in Japan. From the viewpoints of flood control and ecological conservation, it would be necessary to predict the vegetation dynamics accurately for long-term duration. In this research, we have developed a stochastic model for predicting the vegetation dynamics in fluvial floodplains with emphasis on the interaction with flood impacts. The model consists of the following four components: (i) long-term stochastic behavior of flow discharge, (ii) hydrodynamics in a channel with floodplain vegetation, (iii) variation of riverbed topography, and (iv) vegetation dynamics on floodplains. In the vegetation dynamics model, the flood discharge (i) is stochastically simulated using a filtered Poisson process, one of the conventional approaches in hydrological time-series generation. The component for vegetation dynamics (iv) includes the effects of tree growth, mortality by floods, and infant tree recruitment. Vegetation condition has been observed mainly before and after floods since 2008 at a field site located between 23-24 km from the river mouth in Kako River, Japan. The Kako River has the catchment area of 1,730 km2 and the main channel length of 96 km. This site is one of the vegetation overgrowth sites in the Kako River floodplains. The predominant tree species are willows and bamboos. In the field survey, the position, trunk diameter and height of each tree as well as the riverbed materials were measured after several flood events to investigate their impacts on the floodplain vegetation community. This presentation tries to examine effects of anthropogenic river regulations, i.e., thinning and cutting-down, in the vegetated channel in Kako River by using the vegetation dynamics model. Sensitivity of both the flood water level and the vegetation status in the channel is statistically evaluated in terms of the different cutting-down levels, timings and scales of the thinning, etc., by the Monte Carlo simulation of the model.
7. Similarity of vegetation dynamics during interglacial periods
Science.gov (United States)
Cheddadi, Rachid; de Beaulieu, Jacques-Louis; Jouzel, Jean; Andrieu-Ponel, Valérie; Laurent, Jeanne-Marine; Reille, Maurice; Raynaud, Dominique; Bar-Hen, Avner
2005-01-01
The Velay sequence (France) provides a unique, continuous, palynological record spanning the last four climatic cycles. A pollen-based reconstruction of temperature and precipitation displays marked climatic cycles. An analysis of the climate and vegetation changes during the interglacial periods reveals comparable features and identical major vegetation successions. Although Marine Isotope Stage (MIS) 11.3 and the Holocene had similar earth precessional variations, their correspondence in terms of vegetation dynamics is low. MIS 9.5, 7.5, and especially 5.5 display closer correlation to the Holocene than MIS 11.3. Ecological factors, such as the distribution and composition of glacial refugia or postglacial migration patterns, may explain these discrepancies. Comparison of ecosystem dynamics during the past five interglacials suggests that vegetation development in the current interglacial has no analogue from the past 500,000 years. PMID:16162676
8. Modelling vegetation landslides
Science.gov (United States)
Vorpahl, Peter; Dislich, Claudia; Elsenbeer, Helmut; Märker, Michael; Schröder, Boris
2010-05-01
Shallow translational landslides are believed to represent a major ecosystem disturbance in the Andean rain forests of South Ecuador. Aiming at a better understanding of gap dynamics in this mega-diverse ecosystem, we investigated several landslides in an area of undisturbed tropical montane rain forest and found that in some cases almost no inorganic material was involved. Current physically-based landslide models cannot reproduce this type of process, since they focus on soil physical properties. Even though vegetation is incorporated in these models by its weight and by the contribution of roots to soil cohesion and hence to shear resistance, we think that the role of vegetation has to be viewed differently within this ecosystem: Roots do mainly grow in a thick organic layer above the mineral soil and do not penetrate sufficiently deep into the mineral soil to contribute to slope stability according to common models. To accommodate such circumstances, we formulated an extension to the widely used infinite slope model for assessing slope stability, and applied it to our research site. Biomass, root layer and soil properties before sliding events were reconstructed on and close to landslides that occurred within the preceding years. By introduction of an additional factor of safety for the organic layer, we are able to mathematically describe classical shallow translational landslides as well as vegetation slides. A high spatial and temporal variability of vegetation, root layer and soil physical properties within the research area complicate model applications. Thus we assumed spatial gradients for ranges of model parameters and stochastic parameter variations within these ranges according to our field measurements and published data. Finally we outline the model validation by comparison to historical landslide inventories. Possible applications of the model are located within undisturbed tropical montane rain forests and contribute to the fields of automated landslide classification as well as spatiotemporal modelling of landslides and forest gap dynamics.
9. Differences in the behavior and ecology of wild type medaka (Oryzias latipes complex) and an orange commercial variety (himedaka).
Science.gov (United States)
2015-06-01
Genetic disturbance in wild populations of medaka (Oryzias latipes complex) has been mainly caused by the introduction of the orange-red commercial variety medaka (himedaka) in Japan. To examine whether survival, reproduction, and species recognition would be influenced by this difference in body coloration, we conducted three laboratory experiments (predatory pressure, mate choice, schooling behavior) using wild type medaka and himedaka. In the predation experiment using dark chub (Candidia temminckii) as a predator, himedaka were predated upon more often than wild type medaka. However, individuals did not choose mates or select schooling groups based on himedaka or wild type medaka phenotypes. The results indicate that himedaka receive higher predation pressure but are able to easily mate with wild type medaka in a natural environment. To conserve the genetic diversity of wild medaka populations, we need to control the risk of genetic disturbance caused by himedaka. J. Exp. Zool. 323A: 349-358, 2015. © 2015 Wiley Periodicals, Inc. PMID:26054930
10. The importance of evolutionary history in studies of plant physiological ecology: examples from cerrados and forests of central Brazil A importância da história evolutiva em estudos de ecofisiologia vegetal: exemplos dos cerrados e florestas do Brasil Central
OpenAIRE
HOFFMANN, WILLIAM A.; AUGUSTO C. FRANCO
2008-01-01
Studies that compare physiology, anatomy, and ecology across species have offered some of the best insight into adaptation and evolutionary constraints in plants. As a result, the comparative approach has become increasingly used in studies of plant physiological ecology. The high species diversity of Brazilian biomes provides many excellent opportunities for comparative plant ecophysiology, and could be better exploited for understanding the evolution of plant form and function. In this pape...
11. European green lizard (Lacerta viridis) personalities: Linking behavioural types to ecologically relevant traits at different ontogenetic stages.
Science.gov (United States)
Bajer, Katalin; Horváth, Gergely; Molnár, Orsolya; Török, János; Garamszegi, László Zsolt; Herczeg, Gábor
2015-02-01
Consistent individual differences within (animal personality) and across (behavioural syndrome) behaviours became well recognized during the past decade. Nevertheless, our knowledge about the evolutionary and developmental mechanisms behind the phenomena is still incomplete. Here, we explored if risk-taking and exploration were consistent and linked to different ecologically relevant traits in wild-caught adult male European green lizards (Lacerta viridis) and in their 2-3 weeks old laboratory-reared offspring. Both adults and juveniles displayed animal personality, consistency being higher in juveniles. We found correlation between risk-taking and exploration (suggestive of a behavioural syndrome) only in adults. Juveniles were more explorative than adults. Large or ectoparasite-free adult males were more explorative than small or parasitized males. Juvenile females tended to be more risk-taking than males. Behaviour of fathers and their offspring did not correlate. We conclude that European green lizards show high behavioural consistency and age is an important determinant of its strength and links to traits likely affecting fitness. PMID:25475912
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Full Text Available ... Non-starchy Vegetables Grains and Starchy Vegetables Fats Alcohol What Can I Drink? Fruit Dairy Food Tips ... need to later on. Some groups have a higher risk for developing type 2 diabetes than others. ...
13. Biodiversity analysis of vegetation on the Nevada Test Site
International Nuclear Information System (INIS)
The Nevada Test Site (NTS), located in south-central Nevada, encompasses approximately 3,500 square kilometers and straddles two major North American deserts, Mojave and Great Basin. Transitional areas between the two desert types have been created by gradients in elevation, precipitation, temperature, and soils. From 1996 to 1998, more than 1,500 ecological landform units were sampled at the NTS for numerous biotic and abiotic parameters. The data provide a basis for spatial evaluations of biodiversity over landscape scales at the NTS. Biodiversity maps (species richness vs. species abundance) have been produced. Differences in biodiversity among ecoregions and vegetation alliances are presented. Spatial distribution maps of species' presence and abundance provide evidence of where transition zones occur and the resulting impact on biodiversity. The influences of abiotic factors, such as elevation, soil, and precipitation, on biodiversity are assessed
14. Variación de la estructura y composición de comunidades de árboles y arbustos entre tipos de vegetación en la Cuenca de Cuitzeo, Michoacán / Structural and composition variation of tree and shrub communities among vegetation types in the Cuitzeo Basin, Michoacán, Mexico
Scientific Electronic Library Online (English)
Susana, Maza-Villalobos; Franceli, Macedo-Santana; Jorge, Rodríguez-Velázquez; Ken, Oyama; Miguel, Martínez-Ramos.
15. Characterization of vegetation dynamics in Shihezi, Xinjiang using MODIS data
Science.gov (United States)
Song, Sha; Zhang, Xianfeng; Sun, Quan; Lu, Qing
2009-06-01
The vegetation cover is a major feature for an ecological system, especially in arid and semi-arid areas. Percent vegetation cover (PVC) is an integrated index that can indicate vegetation community dynamics. This study aims to use MODIS and TM data to characterize the spatio-temporal dynamics of vegetation covers in Shihezi area, Xinjiang / China. The 16-day composite NDVI of the second half July of 2001 to 2008 was extracted from the MODIS bands. The land cover data was derived from TM data to get better spatial resolution. The dimidiate pixel model was applied to estimate the PVC and the PVC images were classified into five grade categories based on the value of each pixel, and the area for each category was also calculated. The results show that: 1) the area of the low vegetation covers and the middle vegetation covers in the study area in July 2008 reduced 9.18% and 18.53%, respectively with respect to that of 2001 while the area of high vegetation covers is 0.66 times bigger than that of 2001; 2) although the fluctuation of the vegetation covers was observed, the main trend indicates that the green vegetation cover has been recovered ecologically from 2001 to 2008; 3) the natural precipitation has larger impact on the sparsely vegetated areas with a correlation coefficient of 0.82 between the PVC and precipitation in the study area. Finally this case study also demonstrates the usefulness of the MODIS data in the monitoring of vegetation cover dynamics and ecological rehabilitation.
16. Using historic aerial photography and paleohydrologic techniques to assess long-term ecological response to two Montana dam removals.
Science.gov (United States)
Schmitz, Denine; Blank, Matt; Ammondt, Selita; Patten, Duncan T
2009-07-01
The restorative potential of dam removal on ecosystem function depends on the reversibility of dam effects and its operations. While dam removal is an established engineering practice, the need for an understanding of the ecological response remains. We used paleoflood hydrology, hydrologic modeling, and aerial photo interpretation to investigate the long-term ecologic responses to dam failure and breach. We investigated downstream geomorphic and vegetation responses to a dam failure (Pattengail Dam in 1927) and a controlled dam breach, which used natural sediment removal (Mystic Lake Dam in 1985). Our data showed vegetation responses indicative of channel and floodplain evolution at Pattengail. The size of the flood following the Pattengail dam failure initiated a series of channel adjustments and reworked over 19ha of floodplain downstream of the dam. In Mystic, we observed few flood stage indicators and a slight response in floodplain vegetation. We made several findings. (1) Dam removal effects on channel evolution and floodplain development depend on reach types and their responsiveness to flow regime change. (2) Ecologic response to dam removal depends on the sizes and timing of high flow events during and following removal. (3) Paleohydrology can be used to assess historic floods (>20 years). We see the utility of assessing the ecological responsiveness of a system to previous fluvial events or changes in flow regime. Informed about the character of a system based on its history, dam removal scientists can use these tools to set realistic restoration goals for removing a dam. PMID:19042079
17. Ecological Investigation of Three Geophytes in the Deltaic Mediterranean Coast of Egypt
Directory of Open Access Journals (Sweden)
Abdelnaser A. Elzaawely
2013-01-01
Full Text Available This study was conducted to investigate the ecological features of three geophytes namely Asparagus stipularis, Cyperus capitatus and Stipagrostis lanata which grow naturally in the Nile Delta coast of Egypt. C. capitatus and S. lanata are growing in non-saline sandy soils and can tolerate drought stress while, A. stipularis is growing in saline and non-saline sandy and calcareous clay soils and can tolerate drought and salt stress. Multivariate analysis of the vegetation of 100 sampled stands supporting growth of the three geophytic species in the study area led to the recognition of four vegetation groups namely, (A Alhagi graecorum, (B Cyperus capitatus, (C Lycium schweinfurthii var. schweinfurthii-Asparagus stipularis and (D Juncus acutus subsp. acutus. Vegetationally, the vegetation groups associated with the three species can be distinguished into two community types. The first one is psammophytic community comprising vegetation groups A and B that may represent the non-saline sand formations (flats, hummocks and dunes. The second one is halophytic community including vegetation groups C and D that may represent the saline sand flats and salt marsh habitat types, respectively. Sodium adsorption ratio, electrical conductivity, sodium cation, chlorides, silt and sand fractions, pH value, moisture content, bicarbonates and available phosphorus were the most effective soil factors that controlling the abundance and distribution of the plant communities associated with the investigated geophytes. This study showed the ecological features of the selected geophytes in terms of their habitats, associated plant communities and the most edaphic factors controlling their richness and distribution in the study area.
18. Cuantificación del carbono almacenado en formaciones vegetales amazónicas en "CICRA", Madre de Dios (Perú) / Quantification of the carbon storage in amazon vegetation types at "CICRA", Madre de Dios (Peru)
Scientific Electronic Library Online (English)
Carlos, Martel; Lianka, Cairampoma.
2012-08-01
Full Text Available La llanura amazónica peruana se caracteriza por la presencia de múltiples formaciones vegetales. Éstas cada vez reciben mayor impacto por actividades antropogénicas tales como la minería y tala. Todo esto, sumado al cambio climático global, genera desconcierto sobre el futuro de los bosques. La iden [...] tificación de los niveles de almacenamiento de carbono en áreas boscosas, y específicamente en cada formación vegetal, permitiría un mejor manejo de las zonas de conservación, así como identificar las áreas potenciales que servirían para el financiamiento de la absorción de carbono y otros servicios ambientales. El presente estudio fue desarrollado en la estación Biológica del Centro de Investigación y Capacitación Río Los Amigos (CICRA). En el CICRA se identificaron tres formaciones vegetales principales, el bosque de terraza, el bosque inundable y el aguajal. Siendo los bosques de terraza los de mayor extensión y mayor cantidad de carbono acumulado. Como resultado se valorizó la vegetación presente en el CICRA, en alrededor de 11 millones de dólares americanos. El ingreso a la oferta de los bonos de carbono promovería la conservación de los bosques. Abstract in english The Peruvian Amazon Basin is characterized by the presence of multiple vegetation types. They are being given great impact by human activities such as mining and, logging. All this, coupled with global climate change, creates confusion about the future of our forests. The identification of levels of [...] carbon storage in forested areas, and specifically in each vegetation type, would allow better management of conservation areas, and then identify potential areas that could serve to finance carbon sequestration and other environmental services. This study was conducted at the Biological Station for Research and Training Center Rio Los Amigos (CICRA, Spanish acronym). At the station three main formations were identified, alluvial terrace forests, flood terrace forests and Mauritia swamps. The alluvial terrace forest presents the most extensive area and the highest amount of carbon stored. As result, CICRA vegetations were valued at approx. 11 millions U.S. dollars. Admission to the supply of carbon credits could promote Amazon forest conservation.
19. Fertilization types and times of evaluation in health and viability of seeds of vegetable soybeans=Tipos de adubação e épocas de avaliação na sanidade e viabilidade de sementes de soja-hortaliça
Directory of Open Access Journals (Sweden)
Juliana Maria Espíndola Lima
2014-04-01
20. Effects of pomegranate and pomegranate-apple blend juices on the growth characteristics of Alicyclobacillus acidoterrestris DSM 3922 type strain vegetative cells and spores.
Science.gov (United States)
Molva, Celenk; Baysal, Ayse Handan
2015-05-01
The present study examined the growth characteristics of Alicyclobacillus acidoterrestris DSM 3922 vegetative cells and spores after inoculation into apple, pomegranate and pomegranate-apple blend juices (10, 20, 40 and 80%, v/v). Also, the effect of sporulation medium was tested using mineral [Bacillus acidoterrestris agar (BATA) and Bacillus acidocaldarius agar (BAA)] and non-mineral containing media [potato dextrose agar (PDA) and malt extract agar (MEA)]. The juice samples were inoculated separately with approximately 10(5)CFU/mL cells or spores from different sporulation media and then incubated at 37°C for 336 h. The number of cells decreased significantly with increasing pomegranate juice concentration in the blend juices and storage time (pjuices, respectively while the cell counts attained approximately 7.17 log CFU/mL in apple juice after 336 h. On the other hand, the cell growth was inhibited for a certain time, and then the numbers started to increase after 72 and 144 h in 10% and 20% blend juices, respectively. After 336 h, total population among spores produced on PDA, BATA, BAA and MEA indicated 1.49, 1.65, 1.67, and 1.28 log reductions in pomegranate juice; and 1.51, 1.38, 1.40 and 1.16 log reductions in 80% blend juice, respectively. The inhibitory effects of 10%, 20% and 40% blend juices varied depending on the sporulation media used. The results obtained in this study suggested that pomegranate and pomegranate-apple blend juices could inhibit the growth of A. acidoterrestris DSM 3922 vegetative cells and spores. PMID:25676243
1. ISLSCP II Potential Natural Vegetation Cover
National Aeronautics and Space Administration — ABSTRACT: This data set was developed to describe the state of the global land cover in terms of 15 major vegetation types, plus water, before alteration by humans....
2. ISLSCP II Potential Natural Vegetation Cover
National Aeronautics and Space Administration — This data set was developed to describe the state of the global land cover in terms of 15 major vegetation types, plus water, before alteration by humans. It forms...
3. Distinguishing land use types using surface albedo and normalized difference vegetation index derived from the SEBAL model for the Atankwidi and Afram sub-catchments in Ghana
Directory of Open Access Journals (Sweden)
Tayari Salifu
2012-01-01
Full Text Available Distinguishing land use types is mostly done through field surveys which does not easily capture the spatial changes in the land use/cover types. In this study, the Surface Energy Balance Algorithm for Land (SEBAL model was used to estimate surface albedo and NDVI, for different land use/cover types for two sub-catchments (i.e., Atankwidi and Afram in the Volta Basin of Ghana. The mean coefficient of variation (CV for individual land use/cover types compared to the mean CV for a given site was then used to distinguish among the land use/cover types. It was found that these parameters derived from the SEBAL model can be used to distinguish among different land use/cover types in the two sub-catchments. SEBAL estimates for surface albedo and NDVI across the different land use/cover types varied from 0.05 to 0.22 and -0.41 to 0.38, respectively. The range of CVs for surface albedo and NDVI, were 5-22% and 7-175%, respectively across the different land use/cover types for the two catchments. The results of this study demonstrate that SEBAL’s derived surface albedo and NDVI can be used to distinguish land use/cover types in catchments similar to those of the study areas with few ground measurements.
4. Distinguishing land use types using surface albedo and normalized difference vegetation index derived from the SEBAL model for the Atankwidi and Afram sub-catchments in Ghana
OpenAIRE
Tayari Salifu; Wilson Agyei Agyare
2012-01-01
Distinguishing land use types is mostly done through field surveys which does not easily capture the spatial changes in the land use/cover types. In this study, the Surface Energy Balance Algorithm for Land (SEBAL) model was used to estimate surface albedo and NDVI, for different land use/cover types for two sub-catchments (i.e., Atankwidi and Afram) in the Volta Basin of Ghana. The mean coefficient of variation (CV) for individual land use/cover types compared to the mean CV for a given site...
5. ASSESMENT OF ECOLOGICAL STATUS OF DANUBE DELTA LAKES USING INDICATOR MACROPHYTES SPECIES
Directory of Open Access Journals (Sweden)
J. HANGANU
2008-01-01
Full Text Available Implementation of European Water Framework Directive (WFD legislation requires valuation of chemical and ecological status of surface water bodies. One of the biological indicators prescribes for such assessment is aquatic macrophytes taxonomic composition and abundance. In many member states the trophic status of the lakes is asses by calculating trophic index. This paper show the results of applying Schaumburg reference index for 39 water bodies in Danube Delta . Total P, secchi depth, connectivity and substrate type were the main environmental variables calculated versus index values. As lakes differs little in tot. P content, distribution of aquatic vegetation seems to be mainly determined by connectivity type, substrate and lake morphology.
6. Arboreal Ant Assemblages Respond Differently to Food Source and Vegetation Physiognomies: a Study in the Brazilian Atlantic Rain Forest
Directory of Open Access Journals (Sweden)
Janete Jane Resende
2013-07-01
Full Text Available This study aimed to analyze assemblages of arboreal ants in different vegetation physiognomies within the Tropical Moist Forest (Atlantic Rain Forest domain. The study was carried out at the Michelin Ecological Reserve, State of Bahia, Northeast of Brazil. We used sardine (protein resource and honey (carbohydrate resource baits to collect ants foraging in three vegetation types: (1 preserved native forest, (2 forest in regeneration (capoeira with many invasive plants and (3 a mixed agroystem of rubber and cocoa tree plantation. We recorded 69 ant species attracted to the baits, 21 of them exclusive to honey bait and 25 exclusive to the sardine baits. The vegetation physiognomies preserved forest and rubber/cacao agrosystem showed higher species richness in relation to the forest in regeneration (capoeira, suggesting that rubber tree plantations can be a good matrix for the maintenance of some ant species typical of the forest matrix. The type of resource used is important for the structuring of the arboreal ant assemblages. The ants that were attracted to protein resources showed a guild composition that is more differentiated between vegetation types that of ants attracted to glucose resources.
7. Contribution to the Ecology of the Deltaic Mediterranean Coast, Egypt
Directory of Open Access Journals (Sweden)
Ibrahim A. Mashaly
2001-01-01
Full Text Available The ecology of the western section of the Deltaic Mediterranean Coast of Egypt provides a quantitative assessment of the vegetation structure, the main soil characteristics and an evaluation of the relationships between the recognized vegetation groups and environmental attributes. Vegetation and soil were sampled in 75 stands representing the physiographic variation and/or different habitat types in the study area. Relative values of frequency, density and cover for each perennial and the annuals were also recorded. The soil characteristics of collected samples were determined for each stand. 75 sampled stands were classified according to multivariate analysis (classification & ordination into nine defined vegetational groups, namely: group A dominated by Alhagi graecorum Boiss., group B codominated by Phragmites australis (Cav. Trin. ex Steud. and Halocnemum strobilaceum (Pallas M. Bieb, group C dominated by Arthrocnemum macrostachyum (Moric. Moris et Delponte, group D dominated by Sporobolus spicatus (Vahl Kunth, groups E & F dominated by Sporobolus viriginicus (L. Kunth, group G dominated by Stipagrostis scoparia (Trin. & Rupr. De Winter, group H dominated by Echium sericeum Vahl and group I dominated by Lotus creticus L. Detrended Correspondence Analysis (DCA and Canonical Correspondence Analysis (CCA were used to evaluate vegetation-environment relationships. Moisture content, soil texture (coarse & fine sand, soil reaction (pH, calcium carbonate content, sodium adsorption ratio, extractable cations (calcium and potassium and electrical conductivity were highly correlated with the first and second ordination axes. Thus, these soil variables seem to be the main important environmental factors affecting the distribution of vegetation in the study area.
8. Evaluation of Three MODIS-Derived Vegetation Index Time Series for Dryland Vegetation Dynamics Monitoring
Directory of Open Access Journals (Sweden)
Linlin Lu
2015-06-01
Full Text Available Understanding the spatial and temporal dynamics of vegetation is essential in drylands. In this paper, we evaluated three vegetation indices, namely the Normalized Difference Vegetation Index (NDVI, the Soil-Adjusted Vegetation Index (SAVI and the Enhanced Vegetation Index (EVI, derived from the Moderate Resolution Imaging Spectroradiometer (MODIS Surface-Reflectance Product in the Xinjiang Uygur Autonomous Region, China (XUAR, to assess index time series’ suitability for monitoring vegetation dynamics in a dryland environment. The mean annual VI and its variability were generated and analyzed from the three VI time series for the period 2001–2012 across XUAR. Two phenological metrics, start of the season (SOS and end of the season (EOS, were detected and compared for each vegetation type. The mean annual VI images showed similar spatial patterns of vegetation conditions with varying magnitudes. The EVI exhibited high uncertainties in sparsely vegetated lands and forests. The phenological metrics derived from the three VIs are consistent for most vegetation types, with SOS and EOS generated from NDVI showing the largest deviation.
9. Modelling the Ecological Vulnerability to Forest Fires in Mediterranean Ecosystems Using Geographic Information Technologies
Science.gov (United States)
Duguy, Beatriz; Alloza, José Antonio; Baeza, M. Jaime; De la Riva, Juan; Echeverría, Maite; Ibarra, Paloma; Llovet, Juan; Cabello, Fernando Pérez; Rovira, Pere; Vallejo, Ramon V.
2012-12-01
Forest fires represent a major driver of change at the ecosystem and landscape levels in the Mediterranean region. Environmental features and vegetation are key factors to estimate the ecological vulnerability to fire; defined as the degree to which an ecosystem is susceptible to, and unable to cope with, adverse effects of fire (provided a fire occurs). Given the predicted climatic changes for the region, it is urgent to validate spatially explicit tools for assessing this vulnerability in order to support the design of new fire prevention and restoration strategies. This work presents an innovative GIS-based modelling approach to evaluate the ecological vulnerability to fire of an ecosystem, considering its main components (soil and vegetation) and different time scales. The evaluation was structured in three stages: short-term (focussed on soil degradation risk), medium-term (focussed on changes in vegetation), and coupling of the short- and medium-term vulnerabilities. The model was implemented in two regions: Aragón (inland North-eastern Spain) and Valencia (eastern Spain). Maps of the ecological vulnerability to fire were produced at a regional scale. We partially validated the model in a study site combining two complementary approaches that focused on testing the adequacy of model's predictions in three ecosystems, all very common in fire-prone landscapes of eastern Spain: two shrublands and a pine forest. Both approaches were based on the comparison of model's predictions with values of NDVI (Normalized Difference Vegetation Index), which is considered a good proxy for green biomass. Both methods showed that the model's performance is satisfactory when applied to the three selected vegetation types.
10. Mutation breeding in vegetable crops
International Nuclear Information System (INIS)
Vegetables breed by seeds and vegetative organs. In main vegetables, the differentiation of clopping types, the adoption of monoculture and year-round production and shipment are carried out, adapting to various socio-economic and cultivation conditions. Protected agriculture has advanced mainly for fruit vegetables, and the seeds for sale have become almost hybrid varieties. Reflecting the situation like this, the demand for breeding is diversified and characteristic, and the case of applying mutation breeding seems to be many. The present status of the mutation breeding of vegetables is not yet well under way, but about 40 raised varieties have been published in the world. The characters introduced by induced mutation and irradiation were compact form, harvesting aptitude, the forms and properties of stems and leaves, anti-lodging property, the size, form and uniformity of fruits, male sterility and so on. The radiation sources used were mostly gamma ray or X-ray, but sometimes, combined irradiation was used. As the results obtained in Japan, burdocks as an example of gamma ray irradiation to seeds, tomatoes as an example of inducing the compound resistance against disease injury and lettuces as an example of internal beta irradiation are reported. (Kako, I.)
11. Variabilidade morfológica foliar de Miconia sellowiana (DC.) Naudin (Melastomataceae) em diferentes fitofisionomias no Estado do Paraná / Leaf morphology variation of Miconia sellowiana (DC.) Naudin (Melastomataceae) in distinct vegetation types at the state of Paraná
Scientific Electronic Library Online (English)
Maria Regina Torres, Boeger; Renata Maria, Gluzezak; Maria Wilhelmina, Pil; Renato, Goldenberg; Moacyr, Medri.
2008-09-01
12. Vegetation of Werakata National Park, Hunter Valley, New South Wales
OpenAIRE
Bell, Stephen A.J.
2015-01-01
Werakata National Park (32° 50 S, 151° 25 E), near Cessnock in the Hunter Valley of New South Wales, conserves 2145 ha of mostly open forest vegetation, which was formerly widespread in the lower Hunter Valley. Six vegetation communities are delineated; Lower Hunter Spotted Gum – Ironbark Forest occupies most of the Park. All communities present are considered to be poorly conserved in the region and Werakata plays a critical role in the protection of these vegetation types. Two vegetation co...
13. A new world natural vegetation map for global change studies
OpenAIRE
Lapola, David M.; Marcos D. Oyama; Nobre, Carlos A.; Gilvan Sampaio
2008-01-01
We developed a new world natural vegetation map at 1 degree horizontal resolution for use in global climate models. We used the Dorman and Sellers vegetation classification with inclusion of a new biome: tropical seasonal forest, which refers to both deciduous and semi-deciduous tropical forests. SSiB biogeophysical parameters values for this new biome type are presented. Under this new vegetation classification we obtained a consensus map between two global natural vegetation maps widely use...
14. The morphodynamic impact of vegetation and large wood on fluvial systems
Science.gov (United States)
Mao, L.; Bertoldi, W.; Comiti, F.; Gurnell, A. M.; McLelland, S. J.; Osei, N.; Ravazzolo, D.; Tal, M.; Welber, M.; Zanella, S.
2012-04-01
We present preliminary results from a set of recent experiments conducted in the Total Environment Simulator flume at the University of Hull in the framework of the Hydralab IV EU project. The aim of these experiments is to identify and assess the effects of riparian vegetation and large wood on the morphodynamics of braided river channels. The type and size of riparian vegetation is known to play a crucial role in shaping rivers, acting as a proper riparian engineer. Riparian vegetation influences bank stability, increases mean channel depth and can affect planform pattern by reducing the number of active branches. However, the geomorphic effect of plants can continue well after their erosion from banks. As dead or living pieces of large wood are transported through the fluvial network, they can exert a tremendous influence on river erosion and sedimentation processes, channel morphology, channel hydraulics, and ecological diversity of river channels. Our experiments consisted of different scenarios of presence / absence of riparian vegetation (simulated using alfalfa sprouts) and large wood density (simulated using wooden dowels). The experiments were designed to assess both the individual effects of woody debris and bank vegetation, as well as their combined effects. Each experiment has been characterised in terms of planform configuration (the number of active branches per cross-section) and bed topography (surveyed by a terrestrial laser scanner). Detailed DEM differencing was used to investigate sediment transport patterns and dynamics for the different vegetation-wood scenarios. The results of this work will help improve the ability to predict the response of river systems to different disturbances and management strategies.
15. SAFARI 2000 Vegetation Cover Characteristics, Kalahari Transect, Wet Season 2000
National Aeronautics and Space Administration — Vegetation cover and composition, including species types and richness assessments, were measured at four locations along the Kalahari Transect in Botswana...
16. SAFARI 2000 Vegetation Cover Characteristics, Kalahari Transect, Wet Season 2000
National Aeronautics and Space Administration — ABSTRACT: Vegetation cover and composition, including species types and richness assessments, were measured at four locations along the Kalahari Transect in...
17. Research on Chengdu Vegetables Marketing Based on STP Model
OpenAIRE
Qiang Liu; Xiumin Wu
2013-01-01
In this paper, we take the consumers in Chengdu vegetables market as samples, in the form of questionnaires and interviews, to study the consumer motivations and psychology, and make market segmentation of consumers. Results show that the consumers in Chengdu vegetables market can be divided into four types: the safety-pursuing type, the convenient and economical type, the family healthy type, and the fashionable type, among which the safety-pursuing type is the largest. Finally, authors put ...
18. Bacterial Ecology
DEFF Research Database (Denmark)
Fenchel, Tom
2011-01-01
Bacterial ecology is concerned with the interactions between bacteria and their biological and nonbiological environments and with the role of bacteria in biogeochemical element cycling. Many fundamental properties of bacteria are consequences of their small size. Thus, they can efficiently exploit very dilute solutions of organic matter and their potential growth rates are very high. Bacteria do not have a cytoskeleton and they are covered by a rigid cells wall. Therefore they can only take up dissolved low-molecular-weight compounds from their surroundings; when bacteria exploit polymeric compounds these must first be undergo extracellular hydrolysis. Bacteria have a great diversity with respect to types of metabolism that far exceeds the metabolic repertoire of eukaryotic organisms. Bacteria play a fundamental role in the biosphere and certain key processes such as, for example, the production and oxidation of methane, nitrate reduction and fixation of atmospheric nitrogen are exclusively carried out by different groups of bacteria. Some bacterial species – ‘extremophiles’ – thrive in extreme environments in which no eukaryotic organisms can survive with respect to temperature, salinity or pH. Key Concepts:Key Concepts: * Fundamental properties of bacteria are related to their small size and lack of cytoskeleton. * Bacteria display a great diversity in types of metabolism. * Bacteria play a key role in the biosphere in terms of transfer of matter and energy. * A number of fundamental biogeochemical processes are carried exclusively by bacteria. * Bacteria play an important role in all types of habitats including some that cannot support eukaryotic life.
19. Composição florística das formações vegetais sobre uma turfeira topotrófica da planície costeira do Rio Grande do Sul, Brasil / Floristic composition of the vegetation types of a fen on the southern Brazil coastal plain in Rio Grande do Sul, Brazil
Scientific Electronic Library Online (English)
César S. B., Costa; Bruno E., Irgang; Aline R., Peixoto; Juliano C., Marangoni.
2003-06-01
20. Procedures for Sampling Vegetation
US Fish and Wildlife Service, Department of the Interior — This report outlines vegetation sampling procedures used on various refuges in Region 3. The importance of sampling the response of marsh vegetation to management...
1. Caracterização fitofisionômica e levantamento florístico preliminar no Pantanal dos Rios Mortes-Araguaia, Cocalinho, Mato Grosso, Brasil / Vegetation types and preliminary floristic survey in the Mortes-Araguaia Pantanal, Cocalinho, Mato Grosso, Brazil
Scientific Electronic Library Online (English)
Beatriz Schwantes, Marimon; Edson de Souza, Lima.
2001-08-01
2. Caracterização fitofisionômica e levantamento florístico preliminar no Pantanal dos Rios Mortes-Araguaia, Cocalinho, Mato Grosso, Brasil Vegetation types and preliminary floristic survey in the Mortes-Araguaia Pantanal, Cocalinho, Mato Grosso, Brazil
Directory of Open Access Journals (Sweden)
Beatriz Schwantes Marimon
2001-08-01
3. Fungos micorrízicos arbusculares em fitofisionomias do Pantanal da Nhecolândia, Mato Grosso do Sul / Arbuscular mycorrhizal fungi in vegetation types in the Pantanal of Nhecolândia, Mato Grosso do Sul, Brazil
Scientific Electronic Library Online (English)
Plínio Henrique Oliveira, Gomide; Marx Leandro Naves, Silva; Cláudio Roberto Fonsêca Sousa, Soares; Evaldo Luis, Cardoso; Fernanda de, Carvalho; Patrícia Lopes, Leal; Rodrigo Magalhães, Marques; Sidney Luiz, Stürmer.
2014-08-01
4. Final vegetative cover for closed waste sites. Revision 1
Energy Technology Data Exchange (ETDEWEB)
Cook, J.R.; Salvo, S.K.
1993-01-22
Low-level, hazardous, and mixed waste disposal sites normally require some form of plant material to prevent erosion of the final closure cap. Waste disposal sites are closed and capped in a complex scientific manner to minimize water infiltration and percolation into and through the waste material. Turf type grasses are currently being used as an interim vegetative cover for most sites. This coverage allows for required monitoring of the closure cap for settlement and maintenance activities. The purpose of this five year study was to evaluate plant materials for use on wastes sites after the post-closure care period that are quickly and easily established and economically maintained, retard water infiltration, provide maximum year-round evapotranspiration, are ecologically acceptable and do not harm the closure cap. The results of the study suggest that two species of bamboo (Phyllostachys (P.) bissetii and P. rubromarginata) can be utilized to provide long lived, low maintenance, climax vegetation for the waste sites after surveillance and maintenance requirements have ceased.
5. Long-term vegetation monitoring for different habitats in floodplains
Directory of Open Access Journals (Sweden)
LANG Petra
2014-03-01
Full Text Available A floodplain-restoration project along the Danube between Neuburg and Ingolstadt (Germany aims to bring back water and sediment dynamic to the floodplain. The accompanied long-term monitoring has to document the changes in biodiversity related to this new dynamics. Considerations on and results of the vegetation monitoring concept are documented in this paper. In a habitat rich ecosystem like a floodplain different habitats (alluvial forest, semi-aquatic/aquatic sites have different demands on the sampling methods. Therefore, different monitoring designs (preferential, random, systematic, stratified random and transect sampling are discussed and tested for their use in different habitat types of the floodplain. A stratified random sampling is chosen for the alluvial forest stands, as it guarantees an equal distribution of the monitoring plots along the main driving factors, i.e. influence of water. The parameters distance to barrage, ecological flooding, height above thalweg and distance to the new floodplain river are used for stratifying and the plots are placed randomly into these strata, resulting in 117 permanent plots. Due to small changes at the semi-aquatic/aquatic sites a transect sampling was chosen. Further, a rough stratification (channel bed, river bank adjacent floodplain was implemented, which was only possible after the start of the restoration project. To capture the small-scale changes due to the restoration measures on the vegetation, 99 additional plots completed the transect sampling. We conclude that hetereogenous study areas need different monitoring approaches, but, later on, a joint analysis must be possible.
6. Discrepancies among ecological, household, and individual data on fruits and vegetables consumption in Brazil Discrepância entre dados ecológicos, domiciliares e individuais sobre o consumo de frutas e hortaliças no Brasil
OpenAIRE
Rafael Moreira Claro; Patricia Constante Jaime; Karen Lock; Regina Mara Fisberg; Carlos Augusto Monteiro
2010-01-01
Information on fruits and vegetables consumption in Brazil in the three levels of dietary data was analyzed and compared. Data about national supply came from Food Balance Sheets compiled by the FAO; household availability information was obtained from the Brazilian National Household Budget Survey (HBS); and actual intake information came from a large individual dietary intake survey that was representative of the adult population of São Paulo city. All sources of information were collected ...
7. Recent ecological transitions in China: greening, browning, and influential factors
OpenAIRE
Lü, Yihe; Zhang, Liwei; Feng, Xiaoming; Zeng, Yuan; Fu, Bojie; Yao, Xueling; Li, Junran; Wu, Bingfang
2015-01-01
Ecological conservation and restoration are necessary to mitigate environmental degradation problems. China has taken great efforts in such actions. To understand the ecological transition during 2000–2010 in China, this study analysed trends in vegetation change using remote sensing and linear regression. Climate and socioeconomic factors were included to screen the driving forces for vegetation change using correlation or comparative analyses. Our results indicated that China experienced bo...
8. Effect of harvest at different times of day on the physical and chemical characteristics of vegetable-type soybean / Efeito da colheita em diferentes horários do dia sobre as características químicas e físicas de soja tipo hortaliça
Scientific Electronic Library Online (English)
Andréia Cristina, Santana; Mercedes Concórdia, Carrão-Panizzi; José Marcos Gontijo, Mandarino; Rodrigo Santos, Leite; Josemeyre Bonifácio da, Silva; Elza Iouko, Ida.
2012-06-01
Full Text Available O trabalho teve como objetivo avaliar o efeito da colheita em diferentes horários do dia sobre as características químicas e físicas dos grãos de soja da cultivar tipo hortaliça BRS 267, colhidos no estádio R6 (desenvolvimento da semente), e comparar com os colhidos no estádio R8 (maturação). As vag [...] ens da cultivar BRS 267 foram colhidas no estádio de desenvolvimento R6 nos horários das 8, 12 e 18 horas e avaliadas a cor e os grãos analisados quanto à composição química, atividade do inibidor de tripsina, teor do ácido fítico, amido, açúcares, ácidos graxos e isoflavonas. O teor de isoflavonas não diferiu entre os diferentes horários de colheita no estádio R6. No estádio R8 foi encontrado maior teor das formas agliconas. Os diferentes horários de colheita não influenciaram na cor das vagens e nos constituintes químicos dos grãos da cultivar BRS 267 colhida no estádio R6. Os grãos colhidos no estádio R6, quando comparados com os colhidos no estádio R8, apresentaram menor teor de proteínas, ácido fítico e sacarose e maior teor de lipídios, carboidratos, amido, glicose, frutose, estaquiose e ácido linolênico. A qualidade da soja tipo hortaliça BRS 267 no estádio R6 não diferiu com os diferentes horários de colheita, contudo, como produto tipo hortaliça, recomenda-se que a colheita seja realizada no período da manhã, cuja temperatura é mais amena, para facilitar a rápida comercialização e consumo como alimento in natura. Abstract in english The objective of this study was to evaluate the effect of harvest at different times of day on the chemical and physical characteristics of vegetable-type soybean BRS 267 cultivar, harvested at the R6 stage (seed development) and to compare it with that on the grains harvested at the R8 stage (matur [...] ation). The pods of the BRS 267 cultivar were harvested at the R6 stage (at 8:00 AM, 12:00 AM, and 6:00 PM), the color parameters were evaluated, and the grains were analyzed for chemical composition, activity inhibitor trypsin, phytic acid content, starch, sugars, fatty acids, and isoflavones. No differences were observed among the different harvest times in terms of the chemical constituents of vegetable-type soybean BRS 267 cultivar harvested at the R6 stage. Isoflavones content did not change with different harvest times, and the aglycone forms (daidzein, glycitein, and genistein) were found in smaller quantities at the R6 stage compared to the R8 stage. The color of the pods of soybean BRS 267 cultivar, harvested at the R6 stage did not change with different harvest times. The grains harvested at the R6 stage had lower protein content, phytic acid, and sucrose and higher levels of lipids, carbohydrates, starch, glucose, fructose, stachyose, and linolenic acids than those collected at the R8 stage. The different times of harvest did not affect the quality of the vegetable-type soybean BRS 267 cultivar harvested at stage R6. Nevertheless, it is recommended to harvest in the morning, when the temperature is milder, like other vegetables, to facilitate and optimize its marketing and in natura consumption.
9. Effect of harvest at different times of day on the physical and chemical characteristics of vegetable-type soybean Efeito da colheita em diferentes horários do dia sobre as características químicas e físicas de soja tipo hortaliça
Directory of Open Access Journals (Sweden)
Andréia Cristina Santana
2012-06-01
Full Text Available The objective of this study was to evaluate the effect of harvest at different times of day on the chemical and physical characteristics of vegetable-type soybean BRS 267 cultivar, harvested at the R6 stage (seed development and to compare it with that on the grains harvested at the R8 stage (maturation. The pods of the BRS 267 cultivar were harvested at the R6 stage (at 8:00 AM, 12:00 AM, and 6:00 PM, the color parameters were evaluated, and the grains were analyzed for chemical composition, activity inhibitor trypsin, phytic acid content, starch, sugars, fatty acids, and isoflavones. No differences were observed among the different harvest times in terms of the chemical constituents of vegetable-type soybean BRS 267 cultivar harvested at the R6 stage. Isoflavones content did not change with different harvest times, and the aglycone forms (daidzein, glycitein, and genistein were found in smaller quantities at the R6 stage compared to the R8 stage. The color of the pods of soybean BRS 267 cultivar, harvested at the R6 stage did not change with different harvest times. The grains harvested at the R6 stage had lower protein content, phytic acid, and sucrose and higher levels of lipids, carbohydrates, starch, glucose, fructose, stachyose, and linolenic acids than those collected at the R8 stage. The different times of harvest did not affect the quality of the vegetable-type soybean BRS 267 cultivar harvested at stage R6. Nevertheless, it is recommended to harvest in the morning, when the temperature is milder, like other vegetables, to facilitate and optimize its marketing and in natura consumption.O trabalho teve como objetivo avaliar o efeito da colheita em diferentes horários do dia sobre as características químicas e físicas dos grãos de soja da cultivar tipo hortaliça BRS 267, colhidos no estádio R6 (desenvolvimento da semente, e comparar com os colhidos no estádio R8 (maturação. As vagens da cultivar BRS 267 foram colhidas no estádio de desenvolvimento R6 nos horários das 8, 12 e 18 horas e avaliadas a cor e os grãos analisados quanto à composição química, atividade do inibidor de tripsina, teor do ácido fítico, amido, açúcares, ácidos graxos e isoflavonas. O teor de isoflavonas não diferiu entre os diferentes horários de colheita no estádio R6. No estádio R8 foi encontrado maior teor das formas agliconas. Os diferentes horários de colheita não influenciaram na cor das vagens e nos constituintes químicos dos grãos da cultivar BRS 267 colhida no estádio R6. Os grãos colhidos no estádio R6, quando comparados com os colhidos no estádio R8, apresentaram menor teor de proteínas, ácido fítico e sacarose e maior teor de lipídios, carboidratos, amido, glicose, frutose, estaquiose e ácido linolênico. A qualidade da soja tipo hortaliça BRS 267 no estádio R6 não diferiu com os diferentes horários de colheita, contudo, como produto tipo hortaliça, recomenda-se que a colheita seja realizada no período da manhã, cuja temperatura é mais amena, para facilitar a rápida comercialização e consumo como alimento in natura.
10. Variations in fresh fruit and vegetable quality by store type, urban-rural setting and neighbourhood deprivation in Scotland. — Measures of the Food Environment
Science.gov (United States)
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11. Vegetal Optimality and Macro-Scale Dynamic Vegetation - Scaling from Leaf to Landscape
Science.gov (United States)
Quebbeman, J.; Ramirez, J. A.
2014-12-01
Macro-scale spatially distributed hydrologic models require extensive parameterization of both soil and vegetal properties. Proper parameterization of vegetation is critical for understanding vegetal response to hydro-climatic variability, as vegetation provides a key feedback to climate. A common practice for Dynamic Global Vegetation Models is to use plant functional types (PFTs), which limit vegetation to discrete classes. We present a physically based long-term macro-scale coupled vegetation and hydrology model capable of responding dynamically to climate variability, and parameterize it assuming vegetal optimality hypotheses. We hypothesize that canopy scale vegetation will adopt a strategy that maximizes the expected net assimilation, minus photosynthetic system construction and maintenance costs, over an annual basis. We perform stochastic multi-decadal simulations to estimate the expected fitness for a unique vegetal parameterization and water use strategy. As a result, optimal parameter sets are defined, which can be used instead of a PFT characterization of land cover. Estimates of evaporation, transpiration and gross primary production obtained using the optimal parameter sets over a range of climates are then compared against FLUXNET data.
12. Vegetation und Management seltener Pflanzenarten im Küstengrünland einer dänischen Ostseeinsel
DEFF Research Database (Denmark)
Heimes, Christine; Kollmann, Johannes Christian
2010-01-01
Abstract: Grazed coastal grassland in eastern Denmark - Managing plant communities to preserve rare plant species This study analyzes vegetation of coastal grassland in an embanked nature reserve (c. 2000 ha) south of Copenhagen on the island Amager. The focus is on grazing effects on abundance of Iris spuria, Selinum dubium and Cerastium subtetrandrum. The main objectives are to identify plant communities and site factors related to the target species. Considering the ecological requirements of the species it is possible to estimate their potential distribution in the study area. Based on these results, management on the rare plants is discussed. Vegetation data, consisting of 73 relevés collected in summer 2008, are classified using TWINSPAN analysis and ordination by DCA. Thus, the main vegetation units and underlying environmental gradients are identified and assigned to plant communities known from the literature. Recent vegetation changes are analysed by DCA using published data from 2004 and 2006. The main factors defining the grassland vegetation of Vestamager are salinity, moisture and grazing. Nutrientpoor, salt-affected and grazed communities of the Lolio-Cynosuretum are the most common vegetation type in the study area. This association can be divided into a subtype of moist grassland, including species of wetland meadows (Molinion), and drier grassland, with floristic affinities to Mesobromion. In the southwest of the study area, with slightly higher salinity, the Lolio-Cynosuretum is replaced by 243 Juncetum gerardii salt marshes. Within the salt marshes pioneer vegetation is developed on ant hills. The transition between geo- and hydrolitoral is colonized by brackish reeds. On intensely grazed, moist to wet sites the Lolio-Cynosuretum is replaced by the Ranunculo repentis-Alopecuretum geniculati. Tall grassland dominated by Calamagrostis epigejos develops under reduced grazing pressure. Iris spuria and Selinum dubium occur with one stand each in the north of the study area. Thepopulations are associated with drier parts of the Lolio-Cynosuretum juncetosum gerardii. Smaller populations of Selinum dubium are found in Plantago major communities. Cerastium subtetrandrum is represented with several small populations on ant hills in salt-pioneer marsh. Iris spuria is sensitive to grazing, and thus the intensification of grazing on Vestamager has resulted in a decreasing population of this species in the past years. Selinum dubium is more tolerant, and vegetative individuals are able to persist in grazed areas. Cerastium subtetrandrum depends indirectly on grazing. Potential habitats of this species are maintained by grazing. Intensification of grazing and shrub clearance have reduced cover of woody species and tall grasses promoting less competitive species. Recently, a development towards open saltinfluenced grassland can be observed, albeit without increasing floristic diversity. Optimal conservation of the target species seems only feasible if a more diverse management is applied. For conservation of Iris spuria and Selinum dubium a local reduction of grazing is recommended including exclosures. Preservation of Cerastium subtetrandrum, however, depends on low vegetation, which calls for relatively intense grazing. In the long term, higher diversity will only be achieved by spatio-temporal variation of grazing intensity which would also accommodate the different demands of the target species. Keywords: Cerastium subtetrandrum, conservation management, grazing variation, Iris spuria, salt marsh, Selinum dubium, target species.
13. Ecological baseline studies in Los Alamos and Guaje Canyons County of Los Alamos, New Mexico. A two-year study
Energy Technology Data Exchange (ETDEWEB)
Foxx, T.S. [comp.
1995-11-01
During the summers of 1993 and 1994, the Biological Resource Evaluations Team (BRET) of the Environmental Protection Group (ESH-8) conducted baseline studies within two canyon systems, Los Alamos and Guaje Canyons. Biological data was collected within each canyon to provide background and baseline information for Ecological Risk models. Baseline studies included establishment of permanent vegetation plots within each canyon along the elevational gradient. Then, in association with the various vegetation types, surveys were conducted for ground dwelling insects, birds, and small mammals. The stream channels associated with the permanent vegetation plots were characterized and aquatic macroinvertebrates collected within the stream monthly throughout a six-month period. The Geographic Position System (GPS) in combination with ARC INFO was used to map the study areas. Considerable data was collected during these surveys and are summarized in individual chapters.
14. SRS ecology: Environmental information document
Energy Technology Data Exchange (ETDEWEB)
Wike, L.D.; Shipley, R.W.; Bowers, J.A. [and others
1993-09-01
The purpose of this Document is to provide a source of ecological information based on the exiting knowledge gained from research conducted at the Savannah River Site. This document provides a summary and synthesis of ecological research in the three main ecosystem types found at SRS and information on the threatened and endangered species residing there.
15. SRS ecology: Environmental information document
International Nuclear Information System (INIS)
The purpose of this Document is to provide a source of ecological information based on the exiting knowledge gained from research conducted at the Savannah River Site. This document provides a summary and synthesis of ecological research in the three main ecosystem types found at SRS and information on the threatened and endangered species residing there
16. Boundary Shear Stress Along Vegetated Streambanks
Science.gov (United States)
Clark, L. A.; Wynn, T.
2007-12-01
Sediment, a leading cause of water quality impairment, damages aquatic ecosystems and interferes with recreational uses and water treatment processes. Streambank retreat can contribute as much as 85% of watershed sediment yield. Vegetation is an important component of stream restoration designs used to control streambank retreat, but vegetation effects on streambank boundary shear stress (SBSS) need to be quantified. The overall goal of this experiment is to predict boundary shear stress along vegetated streambanks. This goal will be met by determining a method for measuring boundary shear stress in the field along hydraulically rough streambanks, evaluating the effects of streambank vegetation on boundary shear stress in the field, and developing predictive methods based on measurable vegetative properties. First, three streambank vegetation types (herbaceous, shrubbery, and woody) will be modeled in a flume study to examine both boundary shear stress measurement theory and instruments for field use. An appropriate method (law of the wall, Reynold's stresses, TKE, or average wall shear stress) and field instrument (ADV, propeller, or Pitot tube) will be selected, resulting in a field technique to measure SBSS. Predictive methods for estimating SBSS, based on common vegetation measurements, will be developed in the flume study and validated with field data. This research is intended to improve our understanding of the role of riparian vegetation in stream morphology by evaluating the effects of vegetation on boundary shear stress, providing insight to the type and density of vegetation required for streambank stability. The results will also aide in quantifying sediment inputs from streambanks, providing quantitative information for stream restoration projects and watershed management planning.
17. Predicciones de cambios en los principales tipos de vegetación de Chile bajo cambio climático basados en un estudio preliminar: Modelos, incertidumbres y adaptación de la investigación para un mundo de biodiversidad dinámica / Changes in the main vegetation types of Chile predicted under climate change based on a preliminary study: Models, uncertainties and adapting research to a dynamic biodiversity world
Scientific Electronic Library Online (English)
Patricio, Pliscoff; Mary T. K, Arroyo; Lohengrin, Cavieres.
Full Text Available Los efectos del cambio climático sobre la biodiversidad ocurren a diferentes niveles de organización (organismos, especies y ecosistemas). La vegetación se encuentra relacionada directamente con el clima, por lo que se espera que el calentamiento global altere la distribución de los tipos de vegetac [...] ión para el futuro cercano. Usando un enfoque de envoltura bioclimática, los tipos de vegetación de Chile fueron modelados y proyectados usando escenarios del IPCC para el año 2080. Los resultados presentan diferentes transiciones entre los tipos de vegetación, en relación a su distribución latitudinal y altitudinal actual. Entre los cambios principales, se identifica el avance altitudinal de la vegetación alpina, la expansión hacia el sur del desierto absoluto y del matorral desértico sobre el bosque escleróflo. Se esperan cambios en la representación relativa de las áreas protegidas dentro de los diferentes tipos de vegetación de Chile. Las limitaciones del ejercicio de modelación son discutidas junto a la necesidad de mejorar el conocimiento científico sobre procesos biológicos claves como dispersión y polinización. Abstract in english Climate change effects on biodiversity occur at different level of organization (organisms, species and ecosystems). Vegetation type bears a close relationship with climate, such that global warming is ex-pected to alter the distribution of major vegetation types in the near future. Using a bioclima [...] tic envelope modeling approach, the major vegetation types of Chile were modeled and projected using IPCC scenarios for year 2080. The results show transitions among vegetation types in relation to their current latitudinal and altitudinal distribution. Major changes include an upward shift of the alpine vegetation and southward expansion of absolute desert and desert scrub into the present area of sclerophyllous forest. Changes in the relative representation of different vegetation types in Chile´s protected areas can be expected. The limitations of modeling exercises are discussed along with need for better scientific knowledge on key biological processes such as dispersal and pollination.
18. Predicciones de cambios en los principales tipos de vegetación de Chile bajo cambio climático basados en un estudio preliminar: Modelos, incertidumbres y adaptación de la investigación para un mundo de biodiversidad dinámica Changes in the main vegetation types of Chile predicted under climate change based on a preliminary study: Models, uncertainties and adapting research to a dynamic biodiversity world
Directory of Open Access Journals (Sweden)
Patricio Pliscoff
2012-01-01
Full Text Available Los efectos del cambio climático sobre la biodiversidad ocurren a diferentes niveles de organización (organismos, especies y ecosistemas. La vegetación se encuentra relacionada directamente con el clima, por lo que se espera que el calentamiento global altere la distribución de los tipos de vegetación para el futuro cercano. Usando un enfoque de envoltura bioclimática, los tipos de vegetación de Chile fueron modelados y proyectados usando escenarios del IPCC para el año 2080. Los resultados presentan diferentes transiciones entre los tipos de vegetación, en relación a su distribución latitudinal y altitudinal actual. Entre los cambios principales, se identifica el avance altitudinal de la vegetación alpina, la expansión hacia el sur del desierto absoluto y del matorral desértico sobre el bosque escleróflo. Se esperan cambios en la representación relativa de las áreas protegidas dentro de los diferentes tipos de vegetación de Chile. Las limitaciones del ejercicio de modelación son discutidas junto a la necesidad de mejorar el conocimiento científico sobre procesos biológicos claves como dispersión y polinización.Climate change effects on biodiversity occur at different level of organization (organisms, species and ecosystems. Vegetation type bears a close relationship with climate, such that global warming is ex-pected to alter the distribution of major vegetation types in the near future. Using a bioclimatic envelope modeling approach, the major vegetation types of Chile were modeled and projected using IPCC scenarios for year 2080. The results show transitions among vegetation types in relation to their current latitudinal and altitudinal distribution. Major changes include an upward shift of the alpine vegetation and southward expansion of absolute desert and desert scrub into the present area of sclerophyllous forest. Changes in the relative representation of different vegetation types in Chile´s protected areas can be expected. The limitations of modeling exercises are discussed along with need for better scientific knowledge on key biological processes such as dispersal and pollination.
19. Relationships among vegetation, geomorphology and hydrology in the Bananal Island tropical wetlands, Araguaia River basin, Central Brazil
Science.gov (United States)
Valente, C. R.; Latrubesse, E. M.; Ferreira, L. G.
2013-10-01
The Bananal Plain spreading on the Middle Araguaia River basin in Central Brazil at the Cerrado-Amazonia ecotone is a unique system that sustains the largest seasonal wetlands of the Cerrado biome. The huge Bananal Plain is an intracratonic sedimentary basin filled with Pleistocene sediments of the Araguaia formation. Covering approximately two million hectares, the Bananal Island is a major geomorphologic feature of the Bananal plain. Fieldwork and the analysis of a temporal series of MODIS-VI and Landsat ETM images allowed us to discriminate Cerrado phyto-physiognomies on the Bananal Island. Maps of vegetation and geomorphologic units were created, and from the correlation between landforms and vegetation types we identified morpho-vegetation units. Our approach allowed us to postulate that Pleistocene landforms strongly influence, if not dominate, the distribution of vegetation units. For example, the distribution of current gallery forest is not only controlled by active floodplains, but also by alluvial belts abandoned by avulsion. Additionally, arboreal Cerrado vegetation is supported by laterite developed on the sediments of the Araguaia Formation. Some of these inactive landforms are in part modified by the present day geomorphologic processes and colonized by successional vegetation that varies from alluvial forest to Cerrado. Characterized by a very flat landscape with a hindered drainage, the muddy sediments of the Araguaia Formation and the high seasonal rainfall favor the development of regional seasonal wetlands. The Bananal plain is a key area for understanding the Quaternary climatic and biogeographic changes in tropical South America. The control exerted by relict Quaternary landforms on the current vegetation units demonstrates the strong links between geomorphologic aspects of the landscape and ecological patterns. This multidisciplinary approach provides a better understanding of the biogeographic patterns in the Cerrado-Amazon ecotone, which is useful for identifying and designing areas for conservation.
20. Research on Chengdu Vegetables Marketing Based on STP Model
Directory of Open Access Journals (Sweden)
Qiang Liu
2013-04-01
Full Text Available In this paper, we take the consumers in Chengdu vegetables market as samples, in the form of questionnaires and interviews, to study the consumer motivations and psychology, and make market segmentation of consumers. Results show that the consumers in Chengdu vegetables market can be divided into four types: the safety-pursuing type, the convenient and economical type, the family healthy type, and the fashionable type, among which the safety-pursuing type is the largest. Finally, authors put forward some suggestions for Chengdu vegetables market based on current conditions.
1. An ecological analysis of childhood-onset type 1 diabetes incidence and prevalence in Latin America Análisis ecológico de la incidencia y prevalencia en América Latina de diabetes tipo 1 con inicio en la niñez
OpenAIRE
Fernando Collado-Mesa; Alberto Barceló; Arheart, Kristopher L; Messiah, Sarah E.
2004-01-01
OBJECTIVE: To explore, for Latin America, by means of an ecological correlation analysis, the possible relationships between both the incidence and prevalence of childhood type 1 diabetes and selected hypothesized etiological factors, including race/ethnicity, geographical latitude, breast-feeding rates, per capita milk supply and coffee consumption, and wealth-related indicators such as infant mortality rate, life expectancy at birth, and national human development index. METHODS: Recently p...
2. Effect oof some antibiotics, disinfectants, and UV light on vability of vegetative cells and spores of C1. perfringend type A
International Nuclear Information System (INIS)
Cells and spores of 40 strains of C1. perfringens type A, pathogenic for guinea pigs, were tested for resistance to antibiotics, drugs, disinfectants used in surgery and in bacteriological laboratories, and UV light. No correlation was found between thermoresistance of spores and their resistance to other bactericidal agents. Among the common disinfectants, iodine solution showed strong bactericidal and sporostatic activity. Good bactericidal effect was also obtained by combined action of Vescodin and UV light. Drug resistance of C1. perfringens type A strains changed clearly in the past 10 years. Strains inducing gangrene became resistant to penicillin and tetracyclines, which hitherto were commonly applied. Ampicilin can now be recommended, as the antibiotic with strong bactericidal and sporostatic action. (author)
3. Analysis of the vegetation of the sandstone ridges (Ib land type of the north-eastern parts of the Mapungubwe National Park, Limpopo Province, South Africa
Directory of Open Access Journals (Sweden)
Albie R. Gotze
2008-05-01
Full Text Available The establishment of the Mapungubwe National Park has been an objective of several conservationists for many years. The ultimate objective is that this park should become a major component of a Transfrontier National Park shared by Botswana, Zimbabwe and South Africa. The aim of this study was to identify, classify and describe the plant communities present in the Ib land type of the park. Sampling was done by means of the Braun-Blanquet method. A total of 48 stratified random relevés were sampled in the Ib land type. All relevé data were imported into a TURBOVEG database, after which the numerical classification technique TWINSPAN was used as a first approximation. Subsequently, Braun-Blanquet procedures were used to refine data and a phytosociological table was constructed, using the visual editor, MEGATAB. Two plant communities and several subcommunities and variants were identified and described from the phytosociological table.
4. DUCKWEED – A PERSPECTIVE VEGETABLE PLANT
Directory of Open Access Journals (Sweden)
Tsatsenko L. V.
2014-10-01
Full Text Available The questions of use duckweed as green vegetable are considered in article. The structure of types of duckweeds, their biological features, distribution in the world and in the territory of the Krasnodar region is shown. Possibility of their use as biotesters and bioindicators of the water environment, as analytical system for the analysis is shown. Questions of use of duckweed in artificial conditions as well as requirements to the content of culture are considered
5. Fruit and vegetable intake: issues with definition and measurement.
Science.gov (United States)
Roark, Randall A; Niederhauser, Victoria P
2013-01-01
Accurate determination of fruit and vegetable consumption is essential for research that seeks to determine current fruit and vegetable intake patterns, what type and amount of fruit and vegetable consumption is optimal for human health and for evaluating interventions developed to increase such consumption. However, there are many issues that make accurate determination of fruit and vegetable consumption quite difficult. There are many methods used to measure fruit and vegetable intake, but all have limitations. Also, what foods individuals consider to be or to not be fruits or vegetables appear to be quite variable, with such variability often associated with the individual's racial/ethnic background. Researchers and governmental agencies vary with respect to what foods they include and do not include when calculating fruit and vegetable intake. These differences make it difficult to conduct, evaluate and compare studies in this area. The current paper reviews some of the major issues with measuring and determining fruit and vegetable intake. PMID:22475520
6. [Treatment effect of biological filtration and vegetable floating-bed combined system on greenhouse turtle breeding wastewater].
Science.gov (United States)
Chen, Chong-Jun; Zhang, Rui; Xiang, Kun; Wu, Wei-Xiang
2014-08-01
Unorganized discharge of greenhouse turtle breeding wastewater has brought several negative influences on the ecological environment in the rural area of Yangtze River Delta. Biological filtration and vegetable floating-bed combined system is a potential ecological method for greenhouse turtle breeding wastewater treatment. In order to explore the feasibility of this system and evaluate the contribution of vegetable uptake of nitrogen (N) and phosphorus (P) in treating greenhouse turtle breeding wastewater, three types of vegetables, including Ipomoea aquatica, lettuce and celery were selected in this study. Results showed the combined system had a high capacity in simultaneous removal of organic matter, N and P. The removal efficiencies of COD, NH4(+)-N, TN and TP from the wastewater reached up to 93.2%-95.6%, 97.2%-99.6%, 73.9%-93.1% and 74.9%-90.0%, respectively. System with I. aquatica had the highest efficiencies in N and P removal, followed by lettuce and celery. However, plant uptake was not the primary pathway for TN arid TP removal in the combined system. The vegetable uptake of N and P accounted for only 9.1%-25.0% of TN and TP removal from the wastewater while the effect of microorganisms would be dominant for N and P removal. In addition, the highest amounts of N and P uptake in I. aquatica were closely related with the biomass of plant. Results from the study indicated that the biological filtration and vegetable floating-bed combined system was an effective approach to treating greenhouse turtle breeding wastewater in China. PMID:25509094
7. Propagação vegetativa da alfavaca-cravo utilizando diferentes tipos de estacas e substratos Vegetative propagation of the wild basil using different types of cuttings and substrata
Directory of Open Access Journals (Sweden)
Polyana Aparecida D. Ehlert
2004-03-01
Full Text Available A propagação vegetativa é considerada importante ferramenta para o melhoramento de espécies lenhosas e herbáceas e vem sendo amplamente utilizada, visando melhorar e manter variedades de importância econômica e medicinal. Neste contexto utilizou-se estacas de alfavaca-cravo de 15 cm para apicais e 25 cm para as medianas, sendo estas com e sem folhas. As estacas foram plantadas em bandejas de isopor de 72 células, utilizando-se 10 substratos. Após 35 dias, as estacas foram retiradas com cuidado, sendo as partes aéreas e radiculares separadas e acondicionadas em saco de papel e mantidas em estufa a 70ºC por 48 h para posterior avaliação da matéria seca. Analisou-se a percentagem de enraizamento, número de folhas na estaca, peso de matéria seca de folha e de raiz. Não houve interação significativa entre os diferentes tipos de substrato e estaca para percentagem de enraizamento, sendo que os substratos de modo geral diferiram pouco entre si. Entre os tipos de estaca destacaram-se para esta variável a mediana sem folha e a apical com folha. Para as demais variáveis houve interação significativa entre o tipo de estaca e o substrato. A melhor estaca foi a mediana sem folhas plantadas em substrato arisco + esterco + húmus e vermiculita nas seguintes proporções: 20%:40%:40%; 40%:20%:40% e 40%:40%.The vegetative propagation is an important tool for the improvement of woody and herbaceous species and could be an important tool to improve and to maintain varieties of economic and medicinal importance. In this experiment cuttings 15 cm long of the apical portion and also 25 cm long cuttings of the medial portion of the stems, were used both with and without leaves. The cuttings were planted on styrofoam trays with 72 cells, using 10 different substrata. After 35 days, cuttings were carefully removed, the aerial portion being separated from the roots and conditioned in paper bags and maintained in a stove at 70ºC for 48 h, for the dry weight evaluation. There were analyzed the percentage of rooting, number of leaves per cutting and leaf and root dry weight. There was no interaction among substrata and cuttings for the percentage of rooting. Were no significant differences in the rooting among the different substrata used in the experiment there. Better rooting was observed on cuttings from the medial portion of the stem without leaves and from the apical portion with leaves. For the other variables there was significant interaction between the cuttings and the substrata. The cutting that presented best results were those from the medial portion without leaves in the substrata with A+E sandy soil + humus + vermiculite in the following proportions: (20%: 40%:40%; (40%:20%:40% and (40%:40%:20% respectively.
8. Propagação vegetativa da alfavaca-cravo utilizando diferentes tipos de estacas e substratos / Vegetative propagation of the wild basil using different types of cuttings and substrata
Scientific Electronic Library Online (English)
Polyana Aparecida D., Ehlert; José Magno Q., Luz; Renato, Innecco.
2004-03-01
Full Text Available A propagação vegetativa é considerada importante ferramenta para o melhoramento de espécies lenhosas e herbáceas e vem sendo amplamente utilizada, visando melhorar e manter variedades de importância econômica e medicinal. Neste contexto utilizou-se estacas de alfavaca-cravo de 15 cm para apicais e 2 [...] 5 cm para as medianas, sendo estas com e sem folhas. As estacas foram plantadas em bandejas de isopor de 72 células, utilizando-se 10 substratos. Após 35 dias, as estacas foram retiradas com cuidado, sendo as partes aéreas e radiculares separadas e acondicionadas em saco de papel e mantidas em estufa a 70ºC por 48 h para posterior avaliação da matéria seca. Analisou-se a percentagem de enraizamento, número de folhas na estaca, peso de matéria seca de folha e de raiz. Não houve interação significativa entre os diferentes tipos de substrato e estaca para percentagem de enraizamento, sendo que os substratos de modo geral diferiram pouco entre si. Entre os tipos de estaca destacaram-se para esta variável a mediana sem folha e a apical com folha. Para as demais variáveis houve interação significativa entre o tipo de estaca e o substrato. A melhor estaca foi a mediana sem folhas plantadas em substrato arisco + esterco + húmus e vermiculita nas seguintes proporções: 20%:40%:40%; 40%:20%:40% e 40%:40%. Abstract in english The vegetative propagation is an important tool for the improvement of woody and herbaceous species and could be an important tool to improve and to maintain varieties of economic and medicinal importance. In this experiment cuttings 15 cm long of the apical portion and also 25 cm long cuttings of t [...] he medial portion of the stems, were used both with and without leaves. The cuttings were planted on styrofoam trays with 72 cells, using 10 different substrata. After 35 days, cuttings were carefully removed, the aerial portion being separated from the roots and conditioned in paper bags and maintained in a stove at 70ºC for 48 h, for the dry weight evaluation. There were analyzed the percentage of rooting, number of leaves per cutting and leaf and root dry weight. There was no interaction among substrata and cuttings for the percentage of rooting. Were no significant differences in the rooting among the different substrata used in the experiment there. Better rooting was observed on cuttings from the medial portion of the stem without leaves and from the apical portion with leaves. For the other variables there was significant interaction between the cuttings and the substrata. The cutting that presented best results were those from the medial portion without leaves in the substrata with A+E sandy soil + humus + vermiculite in the following proportions: (20%: 40%:40%); (40%:20%:40%) and (40%:40%:20%) respectively.
9. Ecological Economics
OpenAIRE
Martínez Alier, Joan
1994-01-01
Ecological economics is a recently developed field, which sees the economy as a subsystem of a larger finite global ecosystem. Ecological economists question the sustainability of the economy because of its environmental impacts and its material and energy requirements, and also because of the growth of population. Attempts at assigning money values to environmental services and losses, and attempts at correcting macroeconomic accounting, are part of ecological economics, but its main thrust ...
10. Vegetable milks and their fermented derivative products
OpenAIRE
Neus Bernat; Maite Cháfer; Amparo Chiralt; Chelo González-Martínez
2014-01-01
The so-called vegetable milks are in the spotlight thanks to their lactose-free, animal protein-free and cholesterol-free features which fit well with the current demand for healthy food products. Nevertheless, and with the exception of soya, little information is available about these types of milks and their derivatives. The aims of this review, therefore, are to: highlight the main nutritional benefits of the nut and cereal vegetable milks available on the market, fermented or not; describ...
11. Ecological Sections
US Forest Service, Department of Agriculture — A map service on the www depicting ecological section boundaries within the conterminous United States. The map service contains regional geographic delineations...
12. A Case Study of Landholder Attitudes and Behaviour Toward the Conservation of Renosterveld, a Critically Endangered Vegetation Type in Cape Floral Kingdom, South Africa
Science.gov (United States)
Winter, Susan J.; Prozesky, Heidi; Esler, Karen J.
2007-07-01
The attitudes and behaviours of private landholders toward the conservation of a highly transformed and critically endangered habitat, Overberg Coastal Renosterveld (OCR) (a grassy shrubland of the Cape Floral Region, South Africa) are described. Personal, semistructured interviews were conducted with landholders, representing 40 properties in the Overberg region, on topics such as management and utilisation of OCR, the depth of their knowledge of its conservation importance, what they perceive its value to be, and the extent of their willingness to conserve it. General attitudes toward conservation incentives and provincial conservation authorities were also investigated. Farmers more willing to conserve were younger, did not necessarily have a better education, and owned larger farms (>500 ha) with a greater amount of remnant renosterveld (>300 ha) than those less willing to conserve. Attitudes toward the OCR were largely negative, related to associated problem plants and animals and the fact that it is believed not to be economically advantageous to retain it. However, farmers are of the opinion that provision of incentives and increased extension support will provide practical positive inducements for conservation. Landholder education is paramount to prevent further transformation of critically endangered habitats. The success of private-conservation programs depends on the attitudes of landowners toward (1) the particular habitat or species to be conserved (which can vary depending on the type of land use practised and the associated benefits and disadvantages of that habitat type); (2) the conservation agency or extension officers responsible for that area; and (3) willingness of landowners to participate in a conservation program, which is influenced by landowner age, farm size, and the amount of natural habitat left to conserve.
13. Post-fire vegetation recovery in Portugal based on spot/vegetation data
Science.gov (United States)
Gouveia, C.; Dacamara, C. C.; Trigo, R. M.
2010-04-01
A procedure is presented that allows identifying large burned scars and the monitoring of vegetation recovery in the years following major fire episodes. The procedure relies on 10-day fields of Maximum Value Composites of Normalized Difference Vegetation Index (MVC-NDVI), with a 1 km×1 km spatial resolution obtained from the VEGETATION instrument. The identification of fire scars during the extremely severe 2003 fire season is performed based on cluster analysis of NDVI anomalies that persist during the vegetative cycle of the year following the fire event. Two regions containing very large burned scars were selected, located in Central and Southwestern Portugal, respectively, and time series of MVC-NDVI analysed before the fire events took place and throughout the post-fire period. It is shown that post-fire vegetation dynamics in the two selected regions may be characterised based on maps of recovery rates as estimated by fitting a monoparametric model of vegetation recovery to MVC-NDVI data over each burned scar. Results indicated that the recovery process in the region located in Central Portugal is mostly related to fire damage rather than to vegetation density before 2003, whereas the latter seems to have a more prominent role than vegetation conditions after the fire episode, e.g. in the case of the region in Southwestern Portugal. These differences are consistent with the respective predominant types of vegetation. The burned area located in Central Portugal is dominated by Pinus Pinaster whose natural regeneration crucially depends on the destruction of seeds present on the soil surface during the fire, whereas the burned scar in Southwestern Portugal was populated by Eucalyptus that may quickly re-sprout from buds after fire. Besides its simplicity, the monoparametric model of vegetation recovery has the advantage of being easily adapted to other low-resolution satellite data, as well as to other types of vegetation indices.
14. Post-fire vegetation recovery in Portugal based ewline on spot/vegetation data
Directory of Open Access Journals (Sweden)
C. Gouveia
2010-04-01
Full Text Available A procedure is presented that allows identifying large burned scars and the monitoring of vegetation recovery in the years following major fire episodes. The procedure relies on 10-day fields of Maximum Value Composites of Normalized Difference Vegetation Index (MVC-NDVI, with a 1 km×1 km spatial resolution obtained from the VEGETATION instrument. The identification of fire scars during the extremely severe 2003 fire season is performed based on cluster analysis of NDVI anomalies that persist during the vegetative cycle of the year following the fire event. Two regions containing very large burned scars were selected, located in Central and Southwestern Portugal, respectively, and time series of MVC-NDVI analysed before the fire events took place and throughout the post-fire period. It is shown that post-fire vegetation dynamics in the two selected regions may be characterised based on maps of recovery rates as estimated by fitting a monoparametric model of vegetation recovery to MVC-NDVI data over each burned scar. Results indicated that the recovery process in the region located in Central Portugal is mostly related to fire damage rather than to vegetation density before 2003, whereas the latter seems to have a more prominent role than vegetation conditions after the fire episode, e.g. in the case of the region in Southwestern Portugal. These differences are consistent with the respective predominant types of vegetation. The burned area located in Central Portugal is dominated by Pinus Pinaster whose natural regeneration crucially depends on the destruction of seeds present on the soil surface during the fire, whereas the burned scar in Southwestern Portugal was populated by Eucalyptus that may quickly re-sprout from buds after fire. Besides its simplicity, the monoparametric model of vegetation recovery has the advantage of being easily adapted to other low-resolution satellite data, as well as to other types of vegetation indices.
15. Modeling vegetation diversity types in mexico based upon topographic features / Modelado da diversidade de tipos de vegetação no méxico baseado em atributos topográficos / Modelado de la diversidad de tipos de vegetación en méxico basado en atributos topográficos
Scientific Electronic Library Online (English)
Azucena, Pérez; Jean, François Mas; Alejandro, Velázquez; Lorenzo, Vázquez.
2008-02-01
16. Variability of contemporary vegetation around Petuniabukta, central Spitsbergen.
Czech Academy of Sciences Publication Activity Database
Prach, Karel; Klimešová, Jitka; Košnar, J.; Red?enko, O.; Hais, M.
2012-01-01
Ro?. 33, ?. 4 (2012), 383-394. ISSN 0138-0338 R&D Projects: GA MŠk LA341 Institutional research plan: CEZ:AV0Z60050516 Institutional support: RVO:67985939 Keywords : vegetation * ordination * diversity Subject RIV: EH - Ecology, Behaviour Impact factor: 0.745, year: 2012
17. Vegetation development in central European coal mining sites.
Czech Academy of Sciences Publication Activity Database
Prach, Karel
Boca Raton : Taylor & Francis CRC Press, 2013, s. 38-52. ISBN 978-1-4665-9931-4 R&D Projects: GA ?R(CZ) GAP505/11/0256 Institutional support: RVO:67985939 Keywords : succession * vegetation * coal mining Subject RIV: EH - Ecology, Behaviour
18. Site study plan for ecology, Deaf Smith County Site, Texas: Environmental Field Program: Preliminary Draft
International Nuclear Information System (INIS)
The Ecology Site Study Plan describes a field program consisting of studies which include surveys for endangered, threatened, and candidate species; vegetation characterization, including mapping and cover typing, plant succession, wetlands description, and preexisting stresses; and wildlife community characterization, including availability and quality of habitats and descriptions of mammal, bird, reptile, amphibian, and invertebrate populations. The plan for each study describes the need for the study, study design, data management and use, schedule and personnel requirements, and quality assurance. These studies will provide data needed to satisfy requirements contained in, or derived from, the Salt Repository Project Requirements Document (SRP-RD). 83 refs., 3 tabs
19. The underutilized vegetable plants of the federal capital territory (FCT) Abuja of Nigeria
OpenAIRE
Abubakar, S; G.H. Ogbadu; A.B. Usman; O. Segun; O. Olorode; I.U. Samirah
2012-01-01
Promotion and conservation of underutilized indigenous vegetable plants for healthy diet, income generation and food security are the main aims of this ecological survey. Sixty species of flowering plants underutilized as vegetables were collected from the field in the Federal Capital Territory (FCT), across all the six area councils). The family Fabaceae has the highest number of species followed by Asteraceae. Thirty four (56.7%), of the vegetables are herbs, twenty (33.3%) are trees, while...
20. FLORA AND VEGETATION OF GRASSLANDS FROM NIRNOVA RIVER’S BOTTOMLAND
OpenAIRE
MIRON ALIONA
2008-01-01
The paper represents a synthesis of the investigation issues performed in Nârnova River’s grassland during the 2006-2007 vegetation periods. Floristic and phytocoenotic composition of vegetation’s grassland was established. Floristic Inventory of Nârnova River’s grassland includes 193 species, appertaining to 112 genus and 38 families. Flora was analyzed from taxonomic, bioform, geoelement, ecological index, economical importance points of view. 11 species with different endangered level were...
1. Native vegetation of southeast NSW: a revised classification and map for the coast and eastern tablelands
OpenAIRE
Tozer, M. G.; Turner, K.; Keith, D. A.; Tindall, D.; Pennay, C.; Simpson, C; Mackenzie, B; Beukers, P.; Cox, S.
2013-01-01
Native vegetation of the NSW south coast, escarpment and southeast tablelands was classified into 191 floristic assemblages at a level of detail appropriate for the discrimination of Threatened Ecological Communities and other vegetation units referred to in government legislation. Assemblages were derived by a numerical analysis of 10832 field sample quadrats including 8523 compiled from 63 previous vegetation surveys. Past bias in the distribution of field data towards land under public ten...
2. Discrepancies among ecological, household, and individual data on fruits and vegetables consumption in Brazil / Discrepância entre dados ecológicos, domiciliares e individuais sobre o consumo de frutas e hortaliças no Brasil
Scientific Electronic Library Online (English)
Rafael Moreira, Claro; Patricia Constante, Jaime; Karen, Lock; Regina Mara, Fisberg; Carlos Augusto, Monteiro.
2010-11-01
3. Road–side herbaceous vegetation: life history groups and habitat preferences.
Czech Academy of Sciences Publication Activity Database
Šerá, Božena
2010-01-01
Ro?. 58, ?. 1 (2010), s. 69-79. ISSN 1505-2249 R&D Projects: GA MŠk(CZ) OC 350.002 Institutional research plan: CEZ:AV0Z60870520 Keywords : road -side vegetation * road ecology * life form * life history * habitat preference * alien species Subject RIV: EH - Ecology , Behaviour Impact factor: 0.542, year: 2010
4. Selection of Hyperspectral Narrowbands (HNBs) and Composition of Hyperspectral Twoband Vegetation Indices (HVIs) for Biophysical Characterization and Discrimination of Crop Types Using Field Reflectance and Hyperion-EO-1 Data
Science.gov (United States)
Thenkabail, Prasad S.; Mariotto, Isabella; Gumma, Murali Krishna; Middleton, Elizabeth M.; Landis, David R.; Huemmrich, K. Fred
2013-01-01
The overarching goal of this study was to establish optimal hyperspectral vegetation indices (HVIs) and hyperspectral narrowbands (HNBs) that best characterize, classify, model, and map the world's main agricultural crops. The primary objectives were: (1) crop biophysical modeling through HNBs and HVIs, (2) accuracy assessment of crop type discrimination using Wilks' Lambda through a discriminant model, and (3) meta-analysis to select optimal HNBs and HVIs for applications related to agriculture. The study was conducted using two Earth Observing One (EO-1) Hyperion scenes and other surface hyperspectral data for the eight leading worldwide crops (wheat, corn, rice, barley, soybeans, pulses, cotton, and alfalfa) that occupy approx. 70% of all cropland areas globally. This study integrated data collected from multiple study areas in various agroecosystems of Africa, the Middle East, Central Asia, and India. Data were collected for the eight crop types in six distinct growth stages. These included (a) field spectroradiometer measurements (350-2500 nm) sampled at 1-nm discrete bandwidths, and (b) field biophysical variables (e.g., biomass, leaf area index) acquired to correspond with spectroradiometer measurements. The eight crops were described and classified using approx. 20 HNBs. The accuracy of classifying these 8 crops using HNBs was around 95%, which was approx. 25% better than the multi-spectral results possible from Landsat-7's Enhanced Thematic Mapper+ or EO-1's Advanced Land Imager. Further, based on this research and meta-analysis involving over 100 papers, the study established 33 optimal HNBs and an equal number of specific two-band normalized difference HVIs to best model and study specific biophysical and biochemical quantities of major agricultural crops of the world. Redundant bands identified in this study will help overcome the Hughes Phenomenon (or "the curse of high dimensionality") in hyperspectral data for a particular application (e.g., biophysical characterization of crops). The findings of this study will make a significant contribution to future hyperspectral missions such as NASA's HyspIRI. Index Terms-Hyperion, field reflectance, imaging spectroscopy, HyspIRI, biophysical parameters, hyperspectral vegetation indices, hyperspectral narrowbands, broadbands.
5. LANDFIRE Potential Vegetation
US Forest Service, Department of Agriculture — LANDFIRE Potential Vegetation is mapped using predictive landscape models based on extensive field-referenced data and biophysical gradient layers using...
6. LANDFIRE Existing Vegetation
US Forest Service, Department of Agriculture — LANDFIRE Existing Vegetation is mapped using predictive landscape models based on extensive field-referenced data, satellite imagery and biophysical gradient layers...
7. Ecophysiology of forest and savanna vegetation
Science.gov (United States)
Lloyd, J.; Goulden, M. L.; Ometto, J. P.; Patiño, S.; Fyllas, N. M.; Quesada, C. A.
Ecophysiological characteristics of forest and savanna vegetation are compared in an attempt to understand how physiological differences within and between these vegetation types relate to their geographical distributions. A simple ordination first shows that although precipitation exerts a key effect on Amazonian vegetation distributions, soil characteristics are also important. In particular, it is found that under similar precipitation regimes, deciduous forests tend to occur on more fertile soils than do cerrado vegetation types. A high subsoil clay content is also important in allowing the existence of semievergreen forests at only moderate rainfall. Such observations are consistent with biome specific physiological characteristics. For example, deciduous trees have higher nutrient requirements than do evergreen ones which also tend to have characteristics associated with severe water deficits such as a low specific leaf area. Nutrient contents and photosynthetic rates are lower than for savanna than for forest species with several ecosystem characteristics suggesting a primary limitation of nitrogen on savanna productivity. By contrast, phosphorus seems to constrain the productivity of most Amazonian forest types. Differentiation is made between the fast-growing, high-nutrient-requiring forest types of western Amazonia and their counterparts in eastern Amazonia, which tend to occupy infertile but deeper soils of high water-holding ability. On the basis of observed physiological characteristics of the various vegetation forms, it is argued that, should Amazonian precipitation decline sharply in the future, the slower growing forests of eastern Amazonia will transform directly into an evergreen cerrado type vegetation but with the more fertile western Amazonian forests being replaced by some form of drought-deciduous vegetation.
8. The effect of floating vegetation on denitrification and greenhouse gas production in wetland mesocosms
Science.gov (United States)
Jacobs, A. E.; Harrison, J. A.
2012-12-01
9. Warfare Ecology
Science.gov (United States)
Gary E. Machlis (University of Idaho; )
2008-09-01
Among human activities causing ecological change, war is both intensive and far-reaching. Yet environmental research related to warfare is limited in depth and fragmented by discipline. Here we (1) outline a field of study called "warfare ecology," (2) provide a taxonomy of warfare useful for organizing the field, (3) review empirical studies, and (4) propose research directions and policy implications that emerge from the ecological study of warfare. Warfare ecology extends to the three stages of warfare - preparations, war, and postwar activities - and treats biophysical and socioeconomic systems as coupled systems. A review of empirical studies suggests complex relationships between warfare and ecosystem change. Research needs include the development of theory and methods for examining the cascading effects of warfare on specific ecosystems. Policy implications include greater incorporation of ecological science into military planning and improved rehabilitation of postwar ecosystem services, leading to increased peace and security.
10. Natural Plant Communities in View of Response Variables and Ecological Indices from Lalsuhanra Biosphere Reserve, Pakistan
Directory of Open Access Journals (Sweden)
M.S. Chaudhry
2006-01-01
Full Text Available The present study aimed to investigate the ecology of vegetation and to see if the heterogeneity of soil is the main determining factor for the diversity of natural vegetation. Therophytes were the most prominent proportion of life-form spectrum. On the basis of highest IVI three plant communities, Ochthochloa-Cymbopogon- Community, Launaea-Aerva- Community and Lasiurus scindicus-Community were recognized at the three selected habitats. Measurements for ecological indices showed that Launaea-Aerva- Community was more diverse with regard to species number, richness and evenness as compared to the other two plant communities studied. Present results for the pearson moment correlation showed that soil chemical composition may be the main factor not only for array of vegetation but also determines that what type of plant species can grow there. Soil variables were found highly different at all the study sites. We concluded that soil heterogeneity is the major determinant for development of plant communities while climate do not differ much in the area.
11. Bacteriophage ecology in commercial sauerkraut fermentations.
Science.gov (United States)
Lu, Z; Breidt, F; Plengvidhya, V; Fleming, H P
2003-06-01
Knowledge of bacteriophage ecology in vegetable fermentations is essential for developing phage control strategies for consistent and high quality of fermented vegetable products. The ecology of phages infecting lactic acid bacteria (LAB) in commercial sauerkraut fermentations was investigated. Brine samples were taken from four commercial sauerkraut fermentation tanks over a 60- or 100-day period in 2000 and 2001. A total of 171 phage isolates, including at least 26 distinct phages, were obtained. In addition, 28 distinct host strains were isolated and identified as LAB by restriction analysis of the intergenic transcribed spacer region and 16S rRNA sequence analysis. These host strains included Leuconostoc, Weissella, and Lactobacillus species. It was found that there were two phage-host systems in the fermentations corresponding to the population shift from heterofermentative to homofermentative LAB between 3 and 7 days after the start of the fermentations. The data suggested that phages may play an important role in the microbial ecology and succession of LAB species in vegetable fermentations. Eight phage isolates, which were independently obtained two or more times, were further characterized. They belonged to the family Myoviridae or Siphoviridae and showed distinct host ranges and DNA fingerprints. Two of the phage isolates were found to be capable of infecting two Lactobacillus species. The results from this study demonstrated for the first time the complex phage ecology present in commercial sauerkraut fermentations, providing new insights into the bioprocess of vegetable fermentations. PMID:12788716
12. Optimization of intervention levels in ecological restoration.
Czech Academy of Sciences Publication Activity Database
Walker, L. R.; Hölzer, N.; Marrs, R.; del Moral, R.; Prach, Karel
2014-01-01
Ro?. 17, ?. 2 (2014), s. 187-192. ISSN 1402-2001 R&D Projects: GA ?R(CZ) GAP505/11/0256 Institutional support: RVO:67985939 Keywords : succession * vegetation * restoration Subject RIV: EH - Ecology, Behaviour Impact factor: 2.548, year: 2014
13. Biomechanics of fruits and vegetables.
Science.gov (United States)
Peleg, K
1985-01-01
14. Survey of ecological resources at selected US Department of Energy sites
International Nuclear Information System (INIS)
The U.S. Department of Energy (DOE) owns and manages a wide range of ecological resources. During the next 30 years, DOE Headquarters and Field Offices will make land-use planning decisions and conduct environmental remediation and restoration activities in response to federal and state statutes. This document fulfills, in part, DOE's need to know what types of ecological resources it currently owns and manages by synthesizing information on the types and locations of ecological resources at 10 DOE sites: Hanford Site, Idaho National Engineering Laboratory, Lawrence Livermore National Laboratory, Sandia National Laboratory, Rocky Flats Plant, Los Alamos National Laboratory, savannah River Site, Oak Ridge National Laboratory, Argonne National Laboratory, and Fernald Environmental Management Project. This report summarizes information on ecosystems, habitats, and federally listed threatened, endangered, and candidate species that could be stressed by contaminants or physical activity during the restoration process, or by the natural or anthropogenic transport of contaminants from presently contaminated areas into presently uncontaminated areas. This report also provides summary information on the ecosystems, habitats, and threatened and endangered species that exist on each of the 10 sites. Each site chapter contains a general description of the site, including information on size, location, history, geology, hydrology, and climate. Descriptions of the major vegetation and animal communities and of aquatic resources are also provided, with discussions of the treatened or endangered plant or animal species present. Site-specific ecological issues are also discussed in each site chapter. 106 refs., 11 figs., 1 tab
15. Survey of ecological resources at selected US Department of Energy sites
Energy Technology Data Exchange (ETDEWEB)
McAllister, C.; Beckert, H.; Abrams, C. [and others
1996-09-01
The U.S. Department of Energy (DOE) owns and manages a wide range of ecological resources. During the next 30 years, DOE Headquarters and Field Offices will make land-use planning decisions and conduct environmental remediation and restoration activities in response to federal and state statutes. This document fulfills, in part, DOE`s need to know what types of ecological resources it currently owns and manages by synthesizing information on the types and locations of ecological resources at 10 DOE sites: Hanford Site, Idaho National Engineering Laboratory, Lawrence Livermore National Laboratory, Sandia National Laboratory, Rocky Flats Plant, Los Alamos National Laboratory, savannah River Site, Oak Ridge National Laboratory, Argonne National Laboratory, and Fernald Environmental Management Project. This report summarizes information on ecosystems, habitats, and federally listed threatened, endangered, and candidate species that could be stressed by contaminants or physical activity during the restoration process, or by the natural or anthropogenic transport of contaminants from presently contaminated areas into presently uncontaminated areas. This report also provides summary information on the ecosystems, habitats, and threatened and endangered species that exist on each of the 10 sites. Each site chapter contains a general description of the site, including information on size, location, history, geology, hydrology, and climate. Descriptions of the major vegetation and animal communities and of aquatic resources are also provided, with discussions of the treatened or endangered plant or animal species present. Site-specific ecological issues are also discussed in each site chapter. 106 refs., 11 figs., 1 tab.
16. Understory vegetation leads to changes in soil acidity and in microbial communities 27 years after reforestation.
Science.gov (United States)
Fu, Xiaoli; Yang, Fengting; Wang, Jianlei; Di, Yuebao; Dai, Xiaoqin; Zhang, Xinyu; Wang, Huimin
2015-01-01
Experiments with potted plants and removed understories have indicated that understory vegetation often affects the chemical and microbial properties of soil. In this study, we examined the mechanism and extent of the influence of understory vegetation on the chemical and microbial properties of soil in plantation forests. The relationships between the vegetational structure (diversity for different functional layers, aboveground biomass of understory vegetation, and species number) and soil properties (pH, microbial community structure, and levels of soil organic carbon, total nitrogen, and inorganic nitrogen) were analyzed across six reforestation types (three pure needleleaf forests, a needle-broadleaf mixed forest, a broadleaf forest, and a shrubland). Twenty-seven years after reforestation, soil pH significantly decreased by an average of 0.95 across reforestation types. Soil pH was positively correlated with the aboveground biomass of the understory. The levels of total, bacterial, and fungal phospholipid fatty acids, and the fungal:bacterial ratios were similar in the shrubland and the broadleaf forest. Both the aboveground biomass of the understory and the diversity of the tree layer positively influenced the fungal:bacterial ratio. Improving the aboveground biomass of the understory could alleviate soil acidification. An increase in the aboveground biomass of the understory, rather than in understory diversity, enhanced the functional traits of the soil microbial communities. The replacement of pure plantations with mixed-species stands, as well as the enhancement of understory recruitment, can improve the ecological functions of a plantation, as measured by the alleviation of soil acidification and increased fungal dominance. PMID:25261818
17. The minerals and vitamins content variation from different vegetables raw materials
OpenAIRE
Bratu, Magda; Avram, Daniela; Buruleanu, Lavinia
2006-01-01
The vegetables represent a category of protection food products. The juices obtained from fruits and vegetables are very easy assimilated in the human body, comparatively as such vegetables. The study presents the variation of the minerals and vitamins content from some vegetables (carrots, cabbage, red pepper) in function of the race, respectively the compounds dynamic in the vegetables juices obtained from each type or using different combinations from theirs. The mineral salt: calcium, mag...
18. Effects of experimental protocol on global vegetation model accuracy: a comparison of simulated and observed vegetation patterns for Asia
Science.gov (United States)
Tang, Guoping; Shafer, Sarah L.; Barlein, Patrick J.; Holman, Justin O.
2009-01-01
Prognostic vegetation models have been widely used to study the interactions between environmental change and biological systems. This study examines the sensitivity of vegetation model simulations to: (i) the selection of input climatologies representing different time periods and their associated atmospheric CO2 concentrations, (ii) the choice of observed vegetation data for evaluating the model results, and (iii) the methods used to compare simulated and observed vegetation. We use vegetation simulated for Asia by the equilibrium vegetation model BIOME4 as a typical example of vegetation model output. BIOME4 was run using 19 different climatologies and their associated atmospheric CO2 concentrations. The Kappa statistic, Fuzzy Kappa statistic and a newly developed map-comparison method, the Nomad index, were used to quantify the agreement between the biomes simulated under each scenario and the observed vegetation from three different global land- and tree-cover data sets: the global Potential Natural Vegetation data set (PNV), the Global Land Cover Characteristics data set (GLCC), and the Global Land Cover Facility data set (GLCF). The results indicate that the 30-year mean climatology (and its associated atmospheric CO2 concentration) for the time period immediately preceding the collection date of the observed vegetation data produce the most accurate vegetation simulations when compared with all three observed vegetation data sets. The study also indicates that the BIOME4-simulated vegetation for Asia more closely matches the PNV data than the other two observed vegetation data sets. Given the same observed data, the accuracy assessments of the BIOME4 simulations made using the Kappa, Fuzzy Kappa and Nomad index map-comparison methods agree well when the compared vegetation types consist of a large number of spatially continuous grid cells. The results of this analysis can assist model users in designing experimental protocols for simulating vegetation.
19. Shuttle imaging radar-A (SIR-A) data analysis. [geology of the Ozark Plateau of southern Missouri, land use in western Illinois, and vegetation types at Koonamore Station, Australia
Science.gov (United States)
Arvidson, R. E.
1983-01-01
The utility of shuttle imaging radar (SIR-A) data was evaluated in several geological and environmental contexts. For the Ozark Plateau of southern Missouri, SIR-A data were of little use in mapping structural features, because of generally uniform returns. For western Illinois, little was to be gained in terms of identifying land use categories by examining differences between overlapping passes. For southern Australia (Koonamore Station), information ion vegetation types that was not obtainable from LANDSAT MSS data alone was obtained. Specifically, high SIR-A returns in the Australian site were found to correlate with locations where shrubs increase surface roughness appreciably. The Australian study site results demonstrate the synergy of acquiring spectral reflectance and radar data over the same location and time. Such data are especially important in that region, since grazing animals have substantially altered and are continuing to alter the distribution of shrublands, grasslands, and soil exposures. Periodic, synoptic acquisition of MSS and SAR data would be of use in monitoring the dynamics of land-cover change in this environment.
20. Practical aspects of analyzing vegetable oils in fire debris.
Science.gov (United States)
Schwenk, Lisa M; Reardon, Michelle R
2009-07-01
Vegetable oils undergo burning, self-heating, and spontaneous ignition, resulting in their presence in fire debris. As these processes can affect the fatty acid content of vegetable oils, it is important that debris be properly handled in order to obtain reliable and informative data. This research investigated changes in vegetable oil content as a result of storage conditions and different types of burning. Material spiked with vegetable oils and burned was stored under various long-term conditions, and debris was tested by heating overnight using passive headspace concentration. Results indicated that refrigeration is ideal for fire debris samples suspected of containing vegetable oils and that including passive headspace concentration in the analytical scheme would not affect oils. Spontaneous ignition experiments were conducted to compare the effects of various burning processes on vegetable oil content. Vegetable oils that experienced nonpiloted ignition, self-heating, and spontaneous ignition produced noticeably different chromatograms from those that underwent piloted ignition. PMID:19467135
1. Soil and vegetation surveillance
Energy Technology Data Exchange (ETDEWEB)
Antonio, E.J.
1995-06-01
Soil sampling and analysis evaluates long-term contamination trends and monitors environmental radionuclide inventories. This section of the 1994 Hanford Site Environmental Report summarizes the soil and vegetation surveillance programs which were conducted during 1994. Vegetation surveillance is conducted offsite to monitor atmospheric deposition of radioactive materials in areas not under cultivation and onsite at locations adjacent to potential sources of radioactivity.
2. Experimental investigation of the modification of the flow field, past instream vegetation elements, for distinct bedsurface roughness.
Science.gov (United States)
Valyrakis, Manousos; Yagci, Oral; Kitsikoudis, Vasileios; Koursari, Eftychia
2015-04-01
The presence of vegetation in rivers and estuaries has important implications for the modification of the flow field and sediment transport. In-stream vegetation has the potential to regulate the morphology and ecological health of a surface water body, and as such it finds a wide range of applications. Even though a number of controls influencing the local flow field past aquatic vegetation elements or patches of instream vegetation have been identified (such as shape, areal density, size and flexibility), conclusive evidence is lacking, particularly on how sediment transport processes are affected. Here, an experimental study is designed to identify how the flow field past different types of elements simulating in-stream emergent vegetation is modified. Two sets of experiments are conducted, each with a distinct value of high and low hydraulic roughness for the bed surface. In both experiments a rigid cylindrical element, a patch of rigid tubes and a plant shaped element (Cupressus Macrocarpa), simulating instream emergent vegetation are utilized. The flow field is measured at various locations downstream the element and average and turbulent flow statistics are obtained at near bed, mid-flow depth and near the water surface regions. It is found that different structural aspects of the elements, particularly the geometry, can significantly affect the flow field downstream the elements. Specifically, the average flow profiles are practically restored to near ambient flow conditions at about 5 diameters downstream the rigid element, while this happens at longer distances for the other elements. The flow structures shed past the elements are also very distinct, as confirmed via appropriately designed fluorescent dye flow visualizations. Potential ecosystem feedbacks and implications for formation of geospatial patterns are also discussed.
3. Soil-vegetation-atmosphere transfer modeling
Energy Technology Data Exchange (ETDEWEB)
Ikonen, J.P.; Sucksdorff, Y. [Finnish Environment Agency, Helsinki (Finland)
1996-12-31
In this study the soil/vegetation/atmosphere-model based on the formulation of Deardorff was refined to hour basis and applied to a field in Vihti. The effect of model parameters on model results (energy fluxes, temperatures) was also studied as well as the effect of atmospheric conditions. The estimation of atmospheric conditions on the soil-vegetation system as well as an estimation of the effect of vegetation parameters on the atmospheric climate was estimated. Areal surface fluxes, temperatures and moistures were also modelled for some river basins in southern Finland. Land-use and soil parameterisation was developed to include properties and yearly variation of all vegetation and soil types. One classification was selected to describe the hydrothermal properties of the soils. Evapotranspiration was verified against the water balance method
4. Vegetation Dynamics and Community Assembly in Post-Agricultural Heathland
DEFF Research Database (Denmark)
Kepfer Rojas, Sebastian
2014-01-01
Summary This PhD study aims at understanding how biotic, abiotic and stochastic factors interact to structure a heathland vegetation community managed under different traditional land-use practices for centuries prior to abandonment ca. 120 years ago. This study is part of one of the longest spontaneous successional studies of heathland vegetation, where tree colonization and understory vegetation patterns were measured in successive vegetation surveys initiated in 1921. This data was complemented with an intensive survey of the current vegetation patterns and ecological factors. I found that land-use legacies are still present in the soil and were important determinants of vegetation dynamics and community assembly. However, the effects of land-use legacies were mostly mediated by the understory vegetation and differed according to the functional groups. The distance to the edge, a proxy for the proximity to external seed sources, was an important factor affecting different components of the structure of the vegetation, demonstrating the importance of dispersal in the development of the community. My results indicate that the effect of the biotic interactions varies along abiotic gradients (e.g. soil fertility) and interacts with the functional strategies of species to determine the establishment of colonizing species, species’ performances and diversity patterns in the local community. These results have implications for understanding the maintenance of biodiversity, the coexistence of species and the stability of heathland communities, which can be helpful when designing conservation and management actions.
5. Effects of vegetation and sewage load on mangrove crab condition using experimental mesocosms
Science.gov (United States)
Amaral, Valter; Penha-Lopes, Gil; Paula, José
2009-09-01
Constructed wetlands, especially mangroves, have been studied for their usefulness in sewage treatment but the effects of mangrove vegetation and a sewage load on mangrove macrofauna have been given little attention. Ocypodid crabs are important components of mangrove forests and constitute good bioindicators of the functioning of the ecosystem as a whole. In constructed mangrove mesocosms, three vegetation treatments (bare substratum, and Avicennia marina and Rhizophora mucronata seedlings) were subjected to 0, 20, 60 and 100% sewage loads from a nearby hotel. The physiological condition of introduced Uca annulipes and Uca inversa was evaluated in terms of their RNA/DNA ratio after one, five and twelve months, and used as an indicator of ecological function in the system. Crab condition in 0% sewage load was similar to that of wild crabs throughout, suggesting no significant effects of the mesocosms on their RNA/DNA ratio. Overall, both species coped well with the administered sewage loads, suggesting good ecological function in the system. Both species manifested similar patterns in RNA/DNA ratio, being more affected by seasonal fluctuations than by sewage load and vegetation presence and type. Higher RNA/DNA ratios were recorded in the long compared to the short rainy season. Sewage enhanced crab condition in the bare substratum and R. mucronata treatments, especially after one year, probably as a result of enhanced food availability. Uca inversa may be more sensitive to sewage pollution than U. annulipes. In A. marina, no difference in crab condition was observed between sewage loads, and this mangrove yielded the best reduction in sewage impacts. Our results support the usefulness of constructed mangrove areas in sewage treatment, especially if planted with A. marina and inhabited by physiologically healthy ocypodid crabs to enhance the system's performance.
6. Distribution and ecological consequences of ploidy variation in Artemisia sieberi in Iran
Science.gov (United States)
Jalili, Adel; Rabie, Mina; Azarnivand, Hossein; Hodgson, John G.; Arzani, Hossein; Jamzad, Ziba; Asri, Younes; Hamzehee, Behnam; Ghasemi, Farzaneh; Hesamzadeh Hejazi, S. M.; Abbas-Azimi, R.
2013-11-01
Because of their high proportion in the plant kingdom polyploid taxa are considered to have had evolutionary advantages over their diploid ancestors. These advantages may have included new characteristics that enable polyploids to occupy a broader range of habitats. In this context, we assess the ecological range of Artemisia sieberi, a canopy dominant within an important vegetation type in Iran. We assess the extent to which ploidy covaries with geographical and ecological distribution and look for ecologically-significant differences in the functional characteristics of diploids and polyploids. Populations of A. sieberi were sampled widely in Iran and soil characteristics, climate and anatomical and phytochemical plant attributes were measured. Also, in parallel, an independent genetic assessment of populations was carried out using genetic fingerprinting. Two ploidy levels were identified: 75% of the 34 populations of A. sieberi populations sampled were tetraploid (2n = 4x = 36) with the remainder diploid (2n = 2x = 18). Plants of differing ploidy also differed anatomically, genetically and chemically. Tetraploid populations had larger cells and lower stomatal densities and a different essential oil composition. They also appear ecologically distinct, occupying more fertile, mesic habitats than diploids. Genetic fingerprinting revealed the existence of two genetically differentiated subgroups independent of ploidy but with some geographic and ecological pattern. We conclude that diploids and tetraploids have a different ecological distribution and that the absence of mixed diploid-tetraploid populations is a reflection of differing fitness in different habitats. We suspect that a key ecological difference between diploids and tetraploids is the increased stomatal size of tetraploids, possibly resulting from the increased genome and hence cell size following polyploidisation. Polyploid-formation may be constrained in arid habitats by problems of water-use efficiency associated with the larger stomata originally produced.
7. Comparing the use of indigenous knowledge with classification and ordination techniques for assessing the species composition and structure of vegetation in a tropical forest.
Science.gov (United States)
Hernandez-Stefanoni, J Luis; Pineda, Javier Bello; Valdes-Valadez, Gabriela
2006-05-01
Identification of groups that are similar in their floristic composition and structure (habitat types) is essential for conservation and forest managers to allocate high priority areas and to designate areas for reserves, refuges, and other protected areas. In this study, the use of indigenous knowledge for the identification of habitat types in the field was compared against an ecological characterization of habitat types, including their species composition obtained by using classification and ordination techniques for a tropical landscape mosaic in a rural Mayan area of Quintana Roo, Mexico. Plant diversity data calculated from 141 sampled sites chosen randomly on a vegetation class's thematic map obtained by multispectral satellite image classification were used for this propose. Results indicated high similarity in the categorization of vegetation types between the Mayan classification and those obtained by cluster and detrended correspondence analysis. This suggests that indigenous knowledge has a practical use and can be comparable to that obtained by using science-based methods. Finally, identification and mapping of vegetation classes (habitat types) using satellite image classification allowed us to discriminate significantly different species compositions, in such a way that they can provide a useful mechanism for interpolating diversity values over the entire landscape. PMID:16508801
8. Community Ecology
CERN Document Server
1988-01-01
This book presents the proceedings of a workshop on community ecology organized at Davis, in April, 1986, sponsored by the Sloan Foundation. There have been several recent symposia on community ecology (Strong et. al., 1984, Diamond and Case, 1987) which have covered a wide range of topics. The goal of the workshop at Davis was more narrow: to explore the role of scale in developing a theoretical approach to understanding communities. There are a number of aspects of scale that enter into attempts to understand ecological communities. One of the most basic is organizational scale. Should community ecology proceed by building up from population biology? This question and its ramifications are stressed throughout the book and explored in the first chapter by Simon Levin. Notions of scale have long been important in understanding physical systems. Thus, in understanding the interactions of organisms with their physical environment, questions of scale become paramount. These more physical questions illustrate the...
9. Phytoplankton Ecology
Science.gov (United States)
This site describes phytoplankton ecology research by marine ecologists at Mote Marine Laboratory (MML), an independent, nonprofit research organization based in Sarasota, Florida. The emphasis of MML's phytoplankton ecology research is the photophysiology of marine algae -- with recent emphasis on the ability to predict and possibly mitigate blooms of the toxic marine dinoflagellate, Gymnodinium breve. The no-frills phytoplankton ecology homepage describes research and offers data (maps, figures, tables) from 1998 and 1999 projects on Red Tide transects, Nutrient and chlorophyll concentrations, and Ecology and Oceanography of Harmful Algal Blooms (ECOHAB) transect data, among several others. The site also offers general information on Red Tides, Red Tide conditions in Southwest Florida, a chronology of historic Red Tide events, and links to related resources.
10. Vegetation management strategies
Energy Technology Data Exchange (ETDEWEB)
Cancian, D. [Prospect Electricity, Blacktown, NSW (Australia); Martin, S. [Wide Bay-Burnett Electricity Corporation, Maryborough, QLD (Australia); Whitelaw, R.; Woodbury, P. [Prospect Electricity, Blacktown, NSW (Australia); Wassenaar, K. [Vegetation Management Consulting and Auditing Services, Brisbane, QLD (Australia)
1995-12-31
The reliability of electricity supply is affected by the ability to protect conductors from vegetation. Tens of millions of dollars are spent each year in Australia, trying to attain maximum protection of assets, while meeting higher conservation demands from customers and legal compliance. This paper outlines the vegetation management strategies of three electric power distribution utilities in Australia. Prospect Electricity in New South Wales outlines a strategy comprising performance based contract tree trimming, groundling vegetation control, insulated overhead cable systems and community consultation with Community Environment Liaison Committees (CELC). The South East Queensland Electricity Corporation has adopted a similar strategy with particular interest in trials on abseiling versus bucket truck pruning, and strategic pruning versus tree growth regulators. The Wide Bay-Burnett Electricity Corporation in Maryborough, Queensland, has been conducting trial work on vegetation management in its rural areas of supply. Various techniques include leaving understorey plant species, selective and non-selective herbicide application, grass seeding, mechanical clearing techniques, and fire management. There is a need for an integrated approach to vegetation management. This paper covers many of the issues involved in adopting vegetation management strategies that are cost effective and environmentally responsible. It concludes that vegetation management requires a pro-active approach by understanding plant biology and ecosystems which could drastically reduce the costs involved. 1 tab., 11 figs., 10 refs.
11. Ecological shortage
International Nuclear Information System (INIS)
The Meadows study (Limits to Growth) has made the environmental problem popular, but it has reduced the ecological problem to one of population and raw materials, leaving the conditions of social organisation and developmental policy out of consideration. This means that in spite of the repeated moral appeals, developing countries are left to their natural fate while fear and resignation are spread in the industrial nations. The present study tries to contradict this trend in consideration of interdependences in ecological development. (orig.)
12. 13. Vegetation patterns and soils in the Mapimi Bolson (Chihuahuan Desert-Mexico) : 1. Vegetation arcs
OpenAIRE
Cornet, Antoine; Delhoume, Jean-Pierre; Montana, C.
1987-01-01
Des formations végétales connues sous le nom de "brousse tigrée", "vegetation arcs" ou "vegetation stripes" ont été décrites dans diverses régions arides du monde, principalement en Afrique et au Moyen Orient. Dans cette étude, ce type de végétation contractée est décrits pour la première fois dans le Bolson de Mapimi. Cette formation est constituée par une alternance de zones dénudées et de bandes de végétation dont l'axe longitudinal (qui peut varier entre 20 et 70 m) est toujours perpendic...
13. Vegetation against dune mobility.
Science.gov (United States)
Durán, Orencio; Herrmann, Hans J
2006-11-01
Vegetation is the most common and most reliable stabilizer of loose soil or sand. This ancient technique is for the first time cast into a set of equations of motion describing the competition between aeolian sand transport and vegetation growth. Our set of equations is then applied to study quantitatively the transition between barchans and parabolic dunes driven by the dimensionless fixation index theta which is the ratio between the dune characteristic erosion rate and vegetation growth velocity. We find a fixation index theta(c) below which the dunes are stabilized, characterized by scaling laws. PMID:17155579
14. Vegetation against dune mobility
CERN Document Server
Duran, O; Duran, Orencio; Herrmann, Hans J.
2006-01-01
Vegetation is the most common and most reliable stabilizer of loose soil or sand. This ancient technique is for the first time cast into a set of equations of motion describing the competition between aeolian sand transport and vegetation growth. Our set of equations is then applied to study quantitatively the transition between barchans and parabolic dunes driven by the dimensionless fixation index $\\theta$ which is the ratio between dune characteristic erosion rate and vegetation growth velocity. We find a fixation index $\\theta_c$ below which the dunes are stabilized characterized by scaling laws.
15. Moss Distribution and Habitat, To update the Louisiana Coastal Marsh Vegetative Type Map of 1997, 1988, 1978, 1968 and 1949., Published in 2001, 1:24000 (1in=2000ft) scale, Louisiana State University.
NSGIC GIS Inventory (aka Ramona) — This Moss Distribution and Habitat dataset, published at 1:24000 (1in=2000ft) scale as of 2001. It is described as 'To update the Louisiana Coastal Marsh Vegetative...
16. Environmental gradients across wetland vegetation groups in the arid slopes of Western Alborz Mountains, N. Iran
Directory of Open Access Journals (Sweden)
Asghar Kamrani
2011-04-01
Full Text Available Mountain wetlands are unique ecosystems in the arid southern slopes of Alborz range, the second largest range in Iran. The spatial distribution characteristics of wetland vegetation in the arid region of the Alborz and the main factors affecting their distributional patterns were studied. A classification of vegetation and ecological characteristics were carried out using data extracted from 430 relevés in 90 wetland sites. The data were analyzed using Two Way Indicator Species Analysis (TWINSPAN and detrended correspondence analysis (DCA. The wetland vegetation of Alborz Mountain was classified into four large groups. The first vegetation group was calcareous rich vegetation, mainly distributed in the river banks and characterized by helophytes such as Bolboschoenus affinis as indicator species. The second group was saline transitional vegetation, distributed in the ecotone areas and dominated by Phragmites australis. The third vegetation group is wet meadow vegetation which mainly consists of geophytes, endemic and Irano-Turanian species, distributed in the higher altitudes. This vegetation is mainly characterized by indicator species such as Carex orbicularis, high level concentration of Fe2+ and percentage of organic matter in the soil. The fourth vegetation group is aquatic vegetation, distributed in the lakeshores. The aquatic group species are mainly hydrophytic such as Batrachium trichophyllum. The TWINSPAN vegetation groups could be also recognized in the DCA graphs and ecologically differentiated by ANOVA of studied variables. Four vegetation groups can be differentiated on two first axes of indirect ordination. There is a gradient of pH, EC and organic matter associated with altitude on the DCA diagram. Correlation analysis between the axes of DCA and environmental factors shows that altitude, soil texture and other dependant environmental variables (e.g. pH are the main environmental factors affecting the distribution of wetland vegetation groups.
17. Fire Ecology
Science.gov (United States)
18. Phytoplankton and suitability of derived metrics for assessing the ecological status in a limno-reservoir, a Water Framework Directive nondefined type of Mediterranean waterbody
DEFF Research Database (Denmark)
Molina-Navarro, Eugenio; Martinez-Perez, Silvia
2014-01-01
Limno-reservoirs are small waterbodies constructed in the riverine zone of large Mediterranean reservoirs to preserve a constant water level, with the goal of mitigating the undesirable effects of reservoir operation, including those related to water level fluctuations. The Pareja limno-reservoir was among the first limno-reservoirs, and its purposes are both environmental and recreational. Phytoplankton is one of the compulsory biological indicators used to estimate ecological status in lakes and reservoirs in accordance with the European Union Water Framework Directive (WFD). Chlorophyll a (Chl-a) and phytoplankton biovolume in the Pareja limno-reservoir were studied between spring 2008 and winter 2011. Phytoplankton composition was analyzed employing the functional group approach. The suitability of several phytoplankton metrics to assess the ecological status of the limno-reservoir was verified, including Chl-a, total biovolume, cyanobacteria contribution and absolute biovolume, IGA (index de grups algals), MedPTI (Mediterranean Phytoplankton Trophic Index), Assemblage (Q) Index, and PTI (Phytoplankton Trophic Index). Phytoplankton composition was dominated by centric diatoms from functional group B, although they were replaced by other groups in some periods as a response to environmental changes. Checking the response of the phytoplankton metrics to a trophic gradient in addition to Chl-a, we determined that total biovolume, Q Index, and especially PTI were the most appropriate metrics to assess the ecological status of the Pareja limno-reservoir. This approach has relevant management implications for Mediterranean limno-reservoirs. Ecological status assessment may not yet be mandatory in countries such as Spain, but considering environmental and recreational goals, performing such assessments is advisable.
19. Radiocesium cycling in vegetation and soil
International Nuclear Information System (INIS)
Data on cesium dynamics in vegetation and soils are reviewed. Special emphasis is placed on typical environments in the southeastern United States. Clay minerals of soil, especially micaceous types, effectively fix cesium and remove it from biotic components of ecosystems. Fallout 137Cs enters food chains principally by direct deposition on vegetation; uptake by the root pathway is usually less than direct contamination of plant foliage. Cesium-137 levels in vegetation of the southeastern U. S. Coastal Plain are estimated on the basis of direct deposition from the atmosphere and root uptake from soil. Estimated concentrations, based on current concepts of 137Cs dynamics in vegetation and fixation in soil, are in good agreement with observed values of 137Cs in vegetation collected in 1969 and 1970. Mechanisms of direct deposition and of increased uptake by roots due to the absence of micaceous clays adequately explain the higher levels of 137Cs in vegetation of the Coastal Plain and thus are responsible for the elevated 137Cs reported for milk of the Tampa, Fla., milkshed
20. Vegetation Drought Response Index
U.S. Geological Survey, Department of the Interior — VegDRI, short for Vegetation Drought Response Index, is a drought-monitoring tool developed by scientists at EROS in collaboration with the National Drought...
1. Ecologia da paisagem: mapeamento da vegetação da Reserva Biológica da Serra do Japi, Jundiaí, SP, Brasil / Landscape ecology: vegetation map of the Reserva Biológica da Serra do Japi, Jundiaí, SP, Brazil
Scientific Electronic Library Online (English)
Eliana, Cardoso-Leite; Maria Inez, Pagani; Reinaldo, Monteiro; Diana Sarita, Hamburger.
2005-06-01
2. Ecologia da paisagem: mapeamento da vegetação da Reserva Biológica da Serra do Japi, Jundiaí, SP, Brasil Landscape ecology: vegetation map of the Reserva Biológica da Serra do Japi, Jundiaí, SP, Brazil
Directory of Open Access Journals (Sweden)
Eliana Cardoso-Leite
2005-06-01
3. Vegetation against dune mobility
OpenAIRE
Duran, Orencio; Herrmann, Hans J.
2006-01-01
Vegetation is the most common and most reliable stabilizer of loose soil or sand. This ancient technique is for the first time cast into a set of equations of motion describing the competition between aeolian sand transport and vegetation growth. Our set of equations is then applied to study quantitatively the transition between barchans and parabolic dunes driven by the dimensionless fixation index $\\theta$ which is the ratio between dune characteristic erosion rate and veg...
4. Giant mitral valve vegetation
Directory of Open Access Journals (Sweden)
Elif TÜKENMEZ T?GEN
2014-12-01
Full Text Available We present a case of giant mitral valve vegetation in a 66-year-old woman whose clinical status deteriorated rapidly without allowing time for surgery. She died due to a septic embolism and multiorgan failure. Our aim is to stress that the risk of embolic complications is high in cases of large vegetations. The mortality rates are high and these patients should be managed immediately.
5. Assessing vegetation change temporally and spatially in southeastern Arizona
Science.gov (United States)
King, D. M.; Skirvin, S. M.; Holifield Collins, C. D.; Moran, M. S.; Biedenbender, S. H.; Kidwell, M. R.; Weltz, M. A.; Diaz-Gutierrez, A.
2008-05-01
Vegetation species cover and photographic data have been collected at multiple grass- and shrub-dominated sites in 1967, 1994, 1999, and 2005 at the U.S. Department of Agriculture Agricultural Research Service Walnut Gulch Experimental Watershed (WGEW) in southeastern Arizona. This study combines these measurements with meteorological and edaphic information, as well as historic repeat photography from the late 1880s onward and recent satellite imagery to assess vegetation change at WGEW. The results of classification and ordination of repeated transect data showed that WGEW had two main vegetation structural types, shrub dominated and grass dominated. Spatial distribution was closely linked to soil type and variations in annual and August precipitation. Other than the recent appearance of Eragrostis lehmanniana (Lehmann lovegrass) at limited sites in WGEW, little recruitment has taken place in either shrub or grass vegetation types. Effects of recent drought on both vegetation types were apparent in both transect data and enhanced vegetation index data derived from satellite imagery. Historic photos and a better understanding of WGEW geology and geomorphology supported the hypothesis that the shift from grass- to shrub-dominated vegetation occurred substantially before 1967, with considerable spatial variability. This work reaffirmed the value of maintaining long-term data sets for use in assessments of vegetation change.
6. Forest vegetation in view of some scenarios of climate change in Italy
Directory of Open Access Journals (Sweden)
Pignatti G
2011-02-01
Full Text Available The study analyses the relationship between the distribution of the main Italian forest vegetation types and the conditions during average temperature of the coldest month, at present and those predicted for scenarios A2a and B2a of the GCM HADCM3 until the year 2080. With an increased average temperature of the coldest month up to 4.4 °C in 2080, current temperature values for the main forest species will change greatly, creating favorable preconditions for an increased presence of broadleaved deciduous species in mountain altitudes of the Alps, more termophilous broadleaved species on those of the Appennines and more Mediterranean species on lower mountains, hills and lowlands of the country. The results are compared with previsional models of tree species distribution due to predicted climate changes, and the possible influence of some ecological factors is discussed.
7. Computational Ecology: an emerging ecological science
OpenAIRE
WenJun Zhang
2011-01-01
Computational ecology is an emerging science to integrate and synthesize computation intensive areas in ecology. It was clearly defined and described in an earlier study. Aims and scope of computational ecology are further refined in present discussion.
8. METHANE PHYTOREMEDIATION BY VEGETATIVE LANDFILL COVER SYSTEMS
Science.gov (United States)
Landfill gas, consisting of methane and other gases, is produced from organic compounds degrading in landfills, contributes to global climate change, is toxic to various types of vegetation, and may pose a combustion hazard at higher concentrations. New landfills are required to ...
9. GIS analysis of changes in ecological vulnerability using a SPCA model in the Loess plateau of Northern Shaanxi, China.
Science.gov (United States)
Hou, Kang; Li, Xuxiang; Zhang, Jing
2015-04-01
Changes in ecological vulnerability were analyzed for Northern Shaanxi, China using a geographic information system (GIS). An evaluation model was developed using a spatial principal component analysis (SPCA) model containing land use, soil erosion, topography, climate, vegetation and social economy variables. Using this model, an ecological vulnerability index was computed for the research region. Using natural breaks classification (NBC), the evaluation results were divided into five types: potential, slight, light, medium and heavy. The results indicate that there is greater than average optimism about the conditions of the study region, and the ecological vulnerability index (EVI) of the southern eight counties is lower than that of the northern twelve counties. From 1997 to 2011, the ecological vulnerability index gradually decreased, which means that environmental security was gradually enhanced, although there are still some places that have gradually deteriorated over the past 15 years. In the study area, government and economic factors and precipitation are the main reasons for the changes in ecological vulnerability. PMID:25898407
10. GIS Analysis of Changes in Ecological Vulnerability Using a SPCA Model in the Loess Plateau of Northern Shaanxi, China
Directory of Open Access Journals (Sweden)
Kang Hou
2015-04-01
Full Text Available Changes in ecological vulnerability were analyzed for Northern Shaanxi, China using a geographic information system (GIS. An evaluation model was developed using a spatial principal component analysis (SPCA model containing land use, soil erosion, topography, climate, vegetation and social economy variables. Using this model, an ecological vulnerability index was computed for the research region. Using natural breaks classification (NBC, the evaluation results were divided into five types: potential, slight, light, medium and heavy. The results indicate that there is greater than average optimism about the conditions of the study region, and the ecological vulnerability index (EVI of the southern eight counties is lower than that of the northern twelve counties. From 1997 to 2011, the ecological vulnerability index gradually decreased, which means that environmental security was gradually enhanced, although there are still some places that have gradually deteriorated over the past 15 years. In the study area, government and economic factors and precipitation are the main reasons for the changes in ecological vulnerability.
11. Seasonal Changes in the Carbohydrate Pool of an Atlantic Forest Soil under Different Vegetation Types Variación estacional de los carbohidratos en un suelo forestal de la región atlántica desarrollado bajo diferentes tipos de vegetación Variação sazonal dos hidratos de carbono num solo florestal da região Atlântica desenvolvido sob diferentes tipos de vegetação
OpenAIRE
Ángela Martín; Montserrat Díaz-Raviña; Tarsy Carballas
2011-01-01
The seasonal variations of the content and composition of soil carbohydrates, a labile pool of the soil organic matter, were studied in a Humic Cambisol located within the Atlantic temperate-humid zone (Galicia, N.W. of Spain) and developed over basic schists and under different type of vegetation: Quercus robur (climax forest), Pinus pinaster and Eucalyptus globulus. Soil samples from the A horizon (0-15 cm depth) of the three different forests were collected in spring, summer, autu...
12. Recent ecological transitions in China: greening, browning, and influential factors
Science.gov (United States)
Lü, Yihe; Zhang, Liwei; Feng, Xiaoming; Zeng, Yuan; Fu, Bojie; Yao, Xueling; Li, Junran; Wu, Bingfang
2015-03-01
Ecological conservation and restoration are necessary to mitigate environmental degradation problems. China has taken great efforts in such actions. To understand the ecological transition during 2000-2010 in China, this study analysed trends in vegetation change using remote sensing and linear regression. Climate and socioeconomic factors were included to screen the driving forces for vegetation change using correlation or comparative analyses. Our results indicated that China experienced both vegetation greening (restoration) and browning (degradation) with great spatial heterogeneity. Socioeconomic factors, such as human populations and economic production, were the most significant factors for vegetation change. Nature reserves have contributed slightly to the deceleration of vegetation browning and the promotion of greening; however, a large-scale conservation approach beyond nature reserves was more effective. The effectiveness of the Three-North Shelter Forest Program lay between the two above approaches. The findings of this study highlighted that vegetation trend detection is a practical approach for large-scale ecological transition assessments, which can inform decision-making that promotes vegetation greening via proper socioeconomic development and ecosystem management.
13. Application of remote sensing technology in the study of vegetation: Example of vegetation of zhejiang province in China
Science.gov (United States)
CHU, MengRu
2015-04-01
Application of remote sensing technology in the study of vegetation: Example of vegetation of zhejiang province in China Remote sensing technology , is one of the pillars of the space information technology in the 21st century ,play an important role in the study of vegetation. Vegetation coverage as an important parameter reflecting surface information, has been an important research topic in the field of vegetation remote sensing. Administrative region in zhejiang Province as the study area, use of microwave remote sensing and hyperspectral remote sensing technology, combined with the related data, to survey the area of forest resources in zhejiang Province, establishes an index system of sustainable forest resources management ability in zhejiang, and to evaluate its ability. Remote Sensing is developed in the 1960 s of the earth observation technology, comprehensive instruments refers to the application, not contact with the object detection phase, the target characteristics of electromagnetic waves recorded from a distance, through the analysis, reveals the characteristics of the object properties and changes of comprehensive detection technology. Investigation of vegetation is an important application field of remote sensing investigation. Vegetation is an important factor of environment, and also is one of the best sign to reflect the regional ecological environment, at the same times is the interpretation of soil, hydrological elements such as logo, individual or prospecting indicator plant. Vegetation imaging and interpretation of research results for environmental monitoring, biodiversity conservation, agriculture, forestry and other relevant departments to provide information services.Microwave remote sensing hyperspectral remote sensing technology and application in the research of vegetation is an important direction of remote sensing technology in the future. This paper introduces the principle of microwave remote sensing and hyperspectral remote sensing and its application in vegetation studies as an example, the microwave remote sensing and the development direction and prospect of hyperspectral remote sensing.
14. Vegetation study in support of the design and optimization of vegetative soil covers, Sandia National Laboratories, Albuquerque, New Mexico.
Energy Technology Data Exchange (ETDEWEB)
Peace, Gerald (Jerry) L.; Goering, Timothy James (GRAM inc., Albuquerque, NM); Knight, Paul J. (Marron and Associates, Albuquerque, NM); Ashton, Thomas S. (Marron and Associates, Albuquerque, NM)
2004-11-01
A vegetation study was conducted in Technical Area 3 at Sandia National Laboratories, Albuquerque, New Mexico in 2003 to assist in the design and optimization of vegetative soil covers for hazardous, radioactive, and mixed waste landfills at Sandia National Laboratories/New Mexico and Kirtland Air Force Base. The objective of the study was to obtain site-specific, vegetative input parameters for the one-dimensional code UNSAT-H and to identify suitable, diverse native plant species for use on vegetative soil covers that will persist indefinitely as a climax ecological community with little or no maintenance. The identification and selection of appropriate native plant species is critical to the proper design and long-term performance of vegetative soil covers. Major emphasis was placed on the acquisition of representative, site-specific vegetation data. Vegetative input parameters measured in the field during this study include root depth, root length density, and percent bare area. Site-specific leaf area index was not obtained in the area because there was no suitable platform to measure leaf area during the 2003 growing season due to severe drought that has persisted in New Mexico since 1999. Regional LAI data was obtained from two unique desert biomes in New Mexico, Sevilletta Wildlife Refuge and Jornada Research Station.
15. Fungal diseases of some vegetables grown in greenhouse and garden
Directory of Open Access Journals (Sweden)
Halaši Tibor J.
2008-01-01
Full Text Available Aim of this paper was to give an overview of fungal diseases prevailing on the most common vegetables grown in Novi Sad area. For investigation, lettuce and spinach grown in a greenhouse and in open garden were chosen. In greenhouse, optimal conditions for growing lettuce and spinach were maintained, which at the same time favor the development of fungal diseases. The vegetables grown in a protected suburban open garden were more problematic considering fungal diseases. In this paper, the prevention of fungal diseases was emphasized to avoid drastic chemical treatment or minimize its application. The adequate prevention in greenhouse is a good ecological measure.
16. THE VEGETABLES MARKET IN ROMANIA
OpenAIRE
Livia DAVID; Aurelia B?LAN; Elena SOARE; Elena COFAS
2012-01-01
Romania, due to its favourable climatic conditions, is a country with a long tradition in growing vegetables. The importance of growing vegetables is demonstrated both by area cultivated with vegetables and by the large number of individual producers. In this context, the current study comprises, on the one hand, the evolution of vegetable crops specific indicators, and, on the other hand, the evolution of foreign trade. As for the actual production of vegetables in Romania, it cannot provide...
17. Radiocesium cycling in vegetation and soilRadiocesium cycling in vegetation and soil
International Nuclear Information System (INIS)
Data on cesium dynamics in vegetation and soils are reviewed. Special emphasis is placed on typical environments in the southeastern United States. Clay minerals of soil, especially micaceous types, effectively fix cesium and remove it from biotic components of ecosystems. Fallout 137Cs enters food chains principally by direct deposition on vegetation; uptake by the root pathway is usually less than direct contamination of plant foliage. Cesium-137 levels in vegetation of the southeastern U. S. Coastal Plain are estimated on the basis of direct deposition from the atmosphere and root uptake from soil. Estimated concentrations, based on current concepts of 137Cs dynamics in vegetation and fixation in soil, are in good agreement with observed values of 137Cs in vegetation collected in 1969 and 1970. Mechanisms of direct deposition and of increased uptake by roots due to the absence of micaceous clays adequately explain the higher levels of 137Cs in vegetation of the Coastal Plain and thus are responsible for the elevated 137Cs reported for milk of the Tampa, Fla., milkshedData on cesium dynamics in vegetation and soils are reviewed. Special emphasis is placed on typical environments in the southeastern United States. Clay minerals of soil, especially micaceous types, effectively fix cesium and remove it from biotic components of ecosystems. Fallout 137Cs enters food chains principally by direct deposition on vegetation; uptake by the root pathway is usually less than direct contamination of plant foliage. Cesium-137 levels in vegetation of the southeastern U. S. Coastal Plain are estimated on the basis of direct deposition from the atmosphere and root uptake from soil. Estimated concentrations, based on current concepts of 137Cs dynamics in vegetation and fixation in soil, are in good agreement with observed values of 137Cs in vegetation collected in 1969 and 1970. Mechanisms of direct deposition and of increased uptake by roots due to the absence of micaceous clays adequately explain the higher levels of 137Cs in vegetation of the Coastal Plain and thus are responsible for the elevated 137Cs reported for milk of the Tampa, Fla., milkshed
18. Vegetation controls on the maximum size of coastal dunes.
Science.gov (United States)
Durán, Orencio; Moore, Laura J
2013-10-22
Coastal dunes, in particular foredunes, support a resilient ecosystem and reduce coastal vulnerability to storms. In contrast to dry desert dunes, coastal dunes arise from interactions between biological and physical processes. Ecologists have traditionally addressed coastal ecosystems by assuming that they adapt to preexisting dune topography, whereas geomorphologists have studied the properties of foredunes primarily in connection to physical, not biological, factors. Here, we study foredune development using an ecomorphodynamic model that resolves the coevolution of topography and vegetation in response to both physical and ecological factors. We find that foredune growth is eventually limited by a negative feedback between wind flow and topography. As a consequence, steady-state foredunes are scale invariant, which allows us to derive scaling relations for maximum foredune height and formation time. These relations suggest that plant zonation (in particular for strand "dune-building" species) is the primary factor controlling the maximum size of foredunes and therefore the amount of sand stored in a coastal dune system. We also find that aeolian sand supply to the dunes determines the timescale of foredune formation. These results offer a potential explanation for the empirical relation between beach type and foredune size, in which large (small) foredunes are found on dissipative (reflective) beaches. Higher waves associated with dissipative beaches increase the disturbance of strand species, which shifts foredune formation landward and thus leads to larger foredunes. In this scenario, plants play a much more active role in modifying their habitat and altering coastal vulnerability than previously thought. PMID:24101481
19. Data Paper – High Resolution Vegetation Cover Data for the Southern Western Ghats of India. (IFP_ECODATA_VEGETATION)
OpenAIRE
Renard, Quentin; Ramesh, B. R.; Muthusankar, G.; Pelissier, Raphaël
2010-01-01
The Western Ghats form a 1,600 km long escarpment that runs parallel to the southwestern coast of Peninsular India. This relief barrier, which orographically exacerbates the summer monsoon rains, is responsible for steep bioclimatic gradients that have long been recognized as one of the major ecological determinants for the forest vegetation of the region. We report here girded vegetation data at 30' lat/long (ca. 1 km) resolution that cover an area of about 70,000 km2 of the southern Western...
20. Transesterification of vegetable oils: a review
Directory of Open Access Journals (Sweden)
Schuchardt Ulf
1998-01-01
Full Text Available The transesterification of vegetable oils with methanol as well as the main uses of the fatty acid methyl esters are reviewed. The general aspects of this process and the applicability of different types of catalysts (acids, alkaline metal hydroxides, alkoxides and carbonates, enzymes and non-ionic bases, such as amines, amidines, guanidines and triamino(iminophosphoranes are described. Special attention is given to guanidines, which can be easily heterogenized on organic polymers. However, the anchored catalysts show leaching problems. New strategies to obtain non-leaching guanidine-containing catalysts are proposed. Finally, several applications of fatty acid esters, obtained by transesterification of vegetable oils, are described.
1. Vegetation description, rare plant inventory, and vegetation monitoring for Craig Mountain, Idaho
International Nuclear Information System (INIS)
The Craig Mountain Wildlife Mitigation Area was purchased by Bonneville Power Administration (BPA) as partial mitigation for wildlife losses incurred with the inundation of Dworshak Reservoir on the North Fork Clearwater River. Upon completion of the National Environmental Protection Act (NEPA) process, it is proposed that title to mitigation lands will be given to the Idaho Department of Fish and Game (IDFG). Craig Mountain is located at the northern end of the Hells Canyon Ecosystem. It encompasses the plateau and steep canyon slopes extending from the confluence of the Snake and Salmon rivers, northward to near Waha, south of Lewiston, Idaho. The forested summit of Craig Mountain is characterized by gently rolling terrain. The highlands dramatically break into the canyons of the Snake and Salmon rivers at approximately the 4,700 foot contour. The highly dissected canyons are dominated by grassland slopes containing a mosaic of shrubfield, riparian, and woodland habitats. During the 1993 and 1994 field seasons, wildlife, habitat/vegetation, timber, and other resources were systematically inventoried at Craig Mountain to provide Fish and Game managers with information needed to draft an ecologically-based management plan. The results of the habitat/vegetation portion of the inventory are contained in this report. The responsibilities for the Craig Mountain project included: (1) vegetation data collection, and vegetation classification, to help produce a GIS-generated Craig Mountain vegetation map, (2) to determine the distribution and abundance of rare plants populations and make recommendations concerning their management, and (3) to establish a vegetation monitoring program to evaluate the effects of Fish and Game management actions, and to assess progress towards meeting habitat mitigation goals
2. Vegetation Description, Rare Plant Inventory, and Vegetation Monitoring for Craig Mountain, Idaho.
Energy Technology Data Exchange (ETDEWEB)
Mancuso, Michael; Moseley, Robert
1994-12-01
The Craig Mountain Wildlife Mitigation Area was purchased by Bonneville Power Administration (BPA) as partial mitigation for wildlife losses incurred with the inundation of Dworshak Reservoir on the North Fork Clearwater River. Upon completion of the National Environmental Protection Act (NEPA) process, it is proposed that title to mitigation lands will be given to the Idaho Department of Fish and Game (IDFG). Craig Mountain is located at the northern end of the Hells Canyon Ecosystem. It encompasses the plateau and steep canyon slopes extending from the confluence of the Snake and Salmon rivers, northward to near Waha, south of Lewiston, Idaho. The forested summit of Craig Mountain is characterized by gently rolling terrain. The highlands dramatically break into the canyons of the Snake and Salmon rivers at approximately the 4,700 foot contour. The highly dissected canyons are dominated by grassland slopes containing a mosaic of shrubfield, riparian, and woodland habitats. During the 1993 and 1994 field seasons, wildlife, habitat/vegetation, timber, and other resources were systematically inventoried at Craig Mountain to provide Fish and Game managers with information needed to draft an ecologically-based management plan. The results of the habitat/vegetation portion of the inventory are contained in this report. The responsibilities for the Craig Mountain project included: (1) vegetation data collection, and vegetation classification, to help produce a GIS-generated Craig Mountain vegetation map, (2) to determine the distribution and abundance of rare plants populations and make recommendations concerning their management, and (3) to establish a vegetation monitoring program to evaluate the effects of Fish and Game management actions, and to assess progress towards meeting habitat mitigation goals.
3. The relationship between vegetation and groundwater in the hyper-arid Ejina Delta of northwestern China
Science.gov (United States)
Zhang, Y.; Yu, J.; Wang, P.; Xu, Y.
2014-12-01
Vegetation in the hyper-arid Ejina Delta of northwestern China plays irreplaceable role in preventing desertification and maintaining sustainable development in inland Heihe river basin . The groundwater mainly recharged by Heihe river provides the main water source for the vegetation survival in Ejina Delta. While due to extensive water use in mid and upper stream for local economic development, the Ejina Delta had experienced long-term no flow coming in each year and result in groundwater table great decline, which further lead to severely vegetation degradation during the 1990s. Ecological water allocation therefore was implemented in several arid inland basins to prevent ecological degradation. In order to wisely allocating water for ecological use, the relationship between vegetation and groundwater needs to be well understood, that is the aim of this paper. With the GMS software package, a groundwater flow model for the Ejina oasis was established and the spatial distributions of groundwater dynamics during 2000-2011 were simulated. Combing annual average groundwater table and NDVI during growing season on a per-pixel base, it was found that vegetation grew well and had a high biomass when the groundwater was in 1.5-3.8m and vegetation showed the best when the groundwater was about 2m. Further studies conducted at some locations with long-term ground water monitoring showed that when the groundwater table depth was more than 5 and 6 m, the vegetation conditions did not show an obvious response to groundwater table fluctuations; when the groundwater fluctuated between the proper intervals mentioned above, the correlation between vegetation condition and groundwater table were remarkably spatially heterogeneous. This result indicated that future ecological water allocation should consider more spatial heterogeneity of vegetation response to water environment for efficiently using the limited water.
4. Detecting and Tracking Shifts in National Vegetation Composition,Including Donors and Recipients, Across the MODIS Era
Science.gov (United States)
Kumar, J.; Hargrove, W. W.; Norman, S. P.; Hoffman, F. M.
2014-12-01
Forested landscapes are ecologically and economically important, and understanding their dynamics is important for land--management decision making. Forest ecosystems are also under stress, and may be changing due to interannual variability and long term change in climate, natural and anthropogenic disturbance, including human use and management. Detecting and tracking shifts in vegetation is important for land--management, conservation planning, monitoring recovery, managing and monitoring forest structure and composition, maintaining species and habitat diversity and many other purposes.We used MODIS NDVI to create phenological ecoregions, or "phenoregions" having similar annual phenology using a unsupervised clustering method over the period 2000--2012. These statistically derived phenoregions were reclassified to National Land Cover Database (NLCD) classes using the "Mapcurves" algorithm. Interannual transitions in phenologically defined classes are indicator of disturbance and recovery. Because the area within the CONUS is fixed, land cover area changes are a zero-sum game. Changes in one land cover class must be accompained by compensating changes in other classes.We demonstrate a full-circle national-scale accounting system which can track not only area changes in land cover classes, but can show which other compensatory land cover class area changes accompanied them. Area changes in the vegetation distributions, as well as compensatory gains, losses, and trades in area of other land cover types, were mapped and tracked annually during 2000--2012 period at MODIS resolution. The types or labels of the classes used in the accounting can easily be changed to sets of land cover types that maximize the utility of the tracking. For any particular "focus" land cover type, results show which other land covers were donors or recipients of area changes, showing ecologists and land managers alike what vegetation types were given up or gained to offset particular increases or losses.
5. Accuracy Assessment Points for Voyageurs National Park Vegetation Mapping Project
National Park Service, Department of the Interior — Thematic accuracy requirements for the USGS-NPS Vegetation Mapping Program specify 80% accuracy for each map unit that represents USNVC floristic types. A total of...
6. Determinants of vegetation distribution at continental scale. The contribution of natural and anthropogenic factors
DEFF Research Database (Denmark)
Greve, Michelle; Svenning, J.-C.
It has long been debated what determines distribution of vegetation types, though this has rarely been tested at continental scale. We thus aimed to determine which vegetation types are most accurately predicted by natural environmental factors, and which of these factors best predict current vegetation distribution across Africa. Vegetation types were extracted from the Global Land Cover Map for the year 2000, and the distribution of vegetation types modelled in terms of climate, soil and topography. Annual precipitation was the best predictor of the distribution of all vegetation types, and response curves showed that, at lower rainfall levels, an increase in precipitation brought on vegetation types with greater woody cover, though this pattern disappeared at higher rainfall levels. Subsequently, the influence of current and historic human impacts on the distribution of vegetation types was also assessed, and found to be of some importance for most vegetation types. We conclude that, in addition to including environmental variables in predicting vegetation distribution, it is essential that human impact be considered, also in future climate change scenarios.
7. Post-wildfire natural restoration of riparian vegetation under stable hydro-geomorphic conditions: Nahal Grar, Northern Negev Desert, Israel
Science.gov (United States)
Egozi, Roey
2015-04-01
Wildfires are common to the Mediterranean region due to its defined dry season and long historical anthropogenic activities. Most of post-wildfire studies focus on mountains areas and thus refer to the hill-slope and its physical characteristics, e.g. morphology, length, angles, and aspect; its soil characteristics, e.g. type, infiltration rate, repellency; and its vegetative covers, e.g. planted trees vs. natural forest or native vs. exotic vegetation. In contrary there is very limited literature focusing on ecological and hydro-geomorphic aspects of post-wildfire of riparian vegetation / zone probably because of its negligible burned area relative to the spread of the fire, sometimes, over the whole watershed area. The limited literature on the topic is surprising given the fact that riparian vegetation zone has been acknowledged as a unique and important habitat supporting rich biodiversity. Herein we report on a wildfire event occurred on October 14th 2009 in a river section of Nahal Grar, Northern Negev Desert, Israel. The wildfire although was limited in its area (only 3 hectare) extended over the channel alone from bank to bank and thus provide a unique case study of completely burn down of riparian vegetation, mainly dense stands of Common Red (Australis Phragmites. Therefore a detailed study of this event provides an opportunity to tackle one of the basics questions which is determining the rate of natural restoration process that act at the immediate time after the wildfire event occurred. This type of information is most valuable to professional and stakeholders for better management of post-fire riparian zones. The results of the study suggest that under stable conditions, i.e. no major flood events occurred; disturbance time was short and ranged over 200 days due to, almost, immediate recovery of the riparian vegetation. However the re-growth of the riparian vegetation was not even but rather deferential and more complex then reported in the literature. In addition during that period no morphological changes were measured in the channel bed and banks; similarly no changes observed to base flow discharge though slight changes were measured to water pH probably due to the large quantities of ash on river bed.
8. Economic and ecological evaluation of alternative fuels
International Nuclear Information System (INIS)
Under contract with OEMV-AG, a comparative evaluation of biogenic fuels (ethanol, butanol, vegetable oil and methylester of fatty acids ) was carried out from technicoeconomic, agricultural and ecological points of view with special regard to the Austrian conditions of production. Investigations were made for the raw materials starch (corn, wheat, barley, peas and beans), sugar (sugar beet and sweet sorghum) and vegetable oil (rape seed and sunflower). In accordance with the customer, cellulose was excluded from the present investigation. Data for the economic analyses were deduced from the statistics of the financial year 1989/90. (Authors)
9. Spatial organisation of vegetation in water controlled landscapes: the role of vegetation dispersion strategies.
Science.gov (United States)
Thompson, S. E.; Katul, G.
2007-12-01
When investigating the spatial organization of biomass resulting from plant-water feedbacks in arid ecosystems, spatial movement of plants is generally represented as a diffusive processes. Diffusive representations of plant movement have two consequences: they fix the length scale of dispersion to the immediate vicinity of the parent plant, and thus cannot explicitly represent long distance dispersal; and they treat the local gradient of biomass as the determinant of the rate and direction of dispersal. An adaptation of an existing model (Rietkerk et al. 2002) is used to investigate the significance of these assumptions on predicted spatial distributions of vegetation. Model runs were conducted separately with a diffusive and a long-distance dispersive kernel for spatial movement and the resulting spatial organization of vegetation was contrasted. The results indicate that dispersion behavior strongly influences the spatial organization of vegetation in arid landscapes, destabilizing the regular spatial patterns often predicted by models utilizing diffusive representations of biomass movement. The model results provide insight into ecological hypotheses regarding the preponderance of short-range dispersion behavior observed in arid ecosystems, and suggest that this is a consequence of the highly organized nature of the soil water resource. Rietkerk, M., M. C. Boerlijst, F. van Langevelde, R. HilleRisLambers, J. van de Koppel, L. Kumar, H. H. T. Prins, and A. M. de Roos. 2002. Self-organization of vegetation in arid ecosystems. American Naturalist 160:524-530.
10. DINÂMICA DOS ATRIBUTOS FÍSICO-QUÍMICOS E VARIAÇÃO SAZONAL DOS ESTOQUES DE CARBONO NO SOLO EM DIFERENTES FITOFISIONOMIAS DO PANTANAL NORTE MATO-GROSSENSE / DYNAMICS OF CHEMICAL AND PHYSICAL ATTRIBUTES AND SEASONAL VARIATION OF SOIL CARBON STOCKS IN DIFFERENT VEGETATION TYPES OF NORTH PANTANAL OF MATO GROSSO
Scientific Electronic Library Online (English)
Juliana Milesi, Mello; Eduardo Guimarães, Couto; Ricardo Silva Santos, Amorim; Léo Adriano, Chig; Mark Stephen, Johnson; Francisco Almeida, Lobo.
2015-04-01
11. Response characteristics of vegetation and soil environment to permafrost degradation in the upstream regions of the Shule River Basin
International Nuclear Information System (INIS)
12. Response characteristics of vegetation and soil environment to permafrost degradation in the upstream regions of the Shule River Basin
Science.gov (United States)
Chen, Shengyun; Liu, Wenjie; Qin, Xiang; Liu, Yushuo; Zhang, Tongzuo; Chen, Kelong; Hu, Fengzu; Ren, Jiawen; Qin, Dahe
2012-12-01
13. The pasture-type approach for mountain pasture description and management
Directory of Open Access Journals (Sweden)
Giovanni Argenti
2012-10-01
Full Text Available The study of pastoral resources can take different approaches with the main goal of characterizing pasture vegetation and its potential carrying capacity. In recent times, the pasture-type approach has been developed in several Alpine areas – on a regional and on a district scale – starting from sward surveys carried out taking the approach formerly developed by the French pastoral school. The pasture-type approach may play an important role in defining the management of mountain and marginal environments where grazing pressure reduction remarkably affects the agro-ecosystems functions (production, landscape, wildlife, recreation, etc.. This approach is based on the concept of pasture type, which could be defined as a semi-natural vegetation (mainly exploited by grazing animals, rather homogeneous in terms of botanic composition and influenced by environmental factors and agro-pastoral management. This paper presents the pasture-type approach by discussing the results of two large studies carried out in two areas of the south side of the Alps (Piedmont and Veneto. In order to identify pasture types, the vegetation composition was assessed with a point quadrat method. It allowed the computation of species-specific contribution, and of sward forage value and carrying capacity, after a multivariate statistical procedure for type classification and ordination. The site conditions (altitude, slope, aspect and other environmental variables were surveyed. Moreover, to characterize the pasture types from the point of view of the ecological and management factors affecting vegetation composition, the Landolt indicators were used. The results achieved in the two areas were synthesised and organised into reference technical tools with the aim of using the pasture-type approach for pastoral planning. For each study area an identification key to recognize pasture types was drafted, and a handbook containing the technical sheets for pasture type identification, description and management was published. The approach here described enhances the knowledge on mountain pastoral resources, laying the foundations for their conservative management.
14. Spatial Modeling of Urban Vegetation and Land Surface Temperature: A Case Study of Beijing
Directory of Open Access Journals (Sweden)
Chudong Huang
2015-07-01
Full Text Available The coupling relationship between urban vegetation and land surface temperature (LST has been heatedly debated in a variety of environmental studies. This paper studies the urban vegetation information and LST by utilizing a series of remote sensing imagery covering the period from 1990 to 2007. Their coupling relationship is analyzed, in order to provide the basis for ecological planning and environment protection. The results show that the normalized difference vegetation index (NDVI, urban vegetation abundance (UVA and urban forest abundance (UFA are negatively correlated with LST, which means that both urban vegetation and urban forest are capable in decreasing LST. The apparent influence of urban vegetation and urban forest on LST varies with the spatial resolution of the imagery, and peaks at the resolutions ranging from 90 m to 120 m.
15. Comportamento de diferentes sistemas de manejo como fonte ou depósito de carbono em relação à vegetação de Cerrado / Behavior of different management systems as a source or sink of C-CO2 in relation to Cerrado type vegetation
Scientific Electronic Library Online (English)
E. J., Corazza; J. E., Silva; D. V. S., Resck; A. C., Gomes.
1999-06-01
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https://economics.stackexchange.com/questions/47534/why-does-economics-escape-godels-theorems/47544
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Why does economics escape Godel's theorems?
I've seen many professors say that Godel's incompleteness theorems don't apply to economics. Of course I've seen others like Yanis Varoufakis who has on record said that many economics papers defy the basic principles of logic, while also saying that empirical papers can reach the complete opposite conclusion with the same data; both greater and less bargaining power of labor unions can reach the same equilibrium of better profits.
If you look at Godel's incompleteness theorem...
https://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-080-great-ideas-in-theoretical-computer-science-spring-2008/lecture-notes/lec6.pdf
"For any fixed formal system of logic F, if the system is sound and computable, then there exist true statements about the integers that are not provable within the system, F"
1. Is economics a "formal system of logic"? If not, then is it okay to use illogical reasoning in economics? Even if we accept that some reasoning may be intuitive, is the mathematics underlying much of economic theory not susceptible, as a formal system of logic, to Godel's incompleteness theorem? If mathematics is incomplete, then any economic theory that has the pretense of rigor based on mathematics, cannot stand the test of Godel's theorems.
2. If economics is a formal system of logic, then is it sound and computable? I'm guessing all the mathematic formulations of constrained optimization, comparative statics, and causal analysis in econometrics is a "sound and computable" system of applied math, in which case it strives to be a "formal system of logic that is sound and computable". If not, then its effort to be such a field is counterintuitive or even self-defeating in some sense.
3. If economics is formal but not a system, then what is it? Is it a set of competing theories which are themselves systems? If not, then does it house within every theorem or principle a sort of incompleteness where we can relax the requirement for a set of theories to work like a coherent system?
Am I making sense here?
• (-1) "Am I making sense here?" No, not to me. As the first answer suggests, you may be overestimating the meaning of Gödel's Inclompleteness theorem. Varoufakis's critique has nothing to do with theorem. (As far as I can tell.) Then you proceed to asking three seperate questions, some of which seem ill-defined. I like the basic idea of your question, but it seems like you have some strong misconceptions that lead to a strange formulation. Sep 14 at 9:26
• The question seems to be confusing the object of economic science with the logical structure that is applied to it. See also VARulle's answer.
– BrsG
Sep 14 at 9:44
• I think the answers to your questions in (1) are No but irrelevant, No but irrelevant, Yes but irrelevant, and Yes but irrelevant; and so (2) and (3) are not applicable Sep 14 at 15:22
• Related is this very important argument: arxiv.org/pdf/1002.2284.pdf "Markets are efficient if and only if P = NP" Sep 14 at 15:43
• Unlike mathematics, economics is an empirical science. Its challenge is to model how real-world economic works, not whether a platonic model can be complete and consistent. Sep 15 at 7:32
The Incompleteness Theorems apply to computable, first-order, deductive systems. That means that there must be both a computable set of axioms and a computable inference system. In other words, you must be able to write a computer program that can answer the following question: Given a finite sequence of sentences, is it the case that each statement is either an axiom or follows inferentially from previous statements?
Furthermore, the Incompleteness Theorems require that the system be able to interpret Peano arithmetic (i.e., talk about the non-negative integers with plus and times).
Given these constraints, I'm sure it wouldn't be hard to construct such a first-order, axiomatic system for economics (the Austrian concept of praxeology would be a good starting point). Now, would such a system be able to interpret Peano arithmetic? If so, then all the Incompleteness Theorems would tell you is that there would be certain statements (specifically, about integers) that can neither be proved nor refuted. Would such statements be relevant to someone studying economic theory? Godel doesn't tell us. The system would only be incomplete because it could talk about integers and the integers are what create the incompleteness. The fact that the system could also talk about economics would be merely incidental.
I do think that Godel's theorems (and not just the ones about incompleteness; keep in mind that his dissertation was proving the Completeness Theorem) are fascinating. However, I fear that many people exaggerate their significance beyond their original bounds and try to make some grand philosophical epiphany out of them.
• I suspect should you have a running economic theory and test model you will find out when you load the test case for Godel's theorem you discover that the people running the model produce the unproducable result. Sep 14 at 20:10
• @Joshua: It doesn't even get that far. Gödel's theorem basically revolves around the fact that you can encode proofs as numbers (you can encode any data as numbers), and it uses this to reconstruct a version of the liar paradox which uses provability instead of truth (i.e. it finds a way of saying "this statement is unprovable" without the self-reference, by using numbers as a sort of indirection mechanism). This is a valid argument, which happens to be completely uninteresting from an economic perspective. Sep 15 at 20:01
Every science using mathematical reasoning is in some sense subject to Goedel's first incompleteness Theorem, but in a rather trivial sense. This didn't diminish the success of, e.g., physics, and it won't impact economics at all. So yes, in some sense economics is "incomplete", but that's for sure the least of its problems.
Kurt Gödels Incompleteness Theorem is the negative answer to the quest of the mathematician Davild Hilbert in the early 20th century to find a set of complete and consistent axioms upon which to build the whole of mathematics. It turns out that it is not possible to find such a set. Any set of axioms which is complete will lead to inconsistencies; and every set of axioms that avoids inconsistencies will be incomplete.
This is it, basically. It is a highly technical mathematical proof which has very little impact on any real world application. It decided a long discussion between mathematicians, solving an until then unknown question which is mainly interesting for mathematicians: it tells them that it makes no sense to spend decades of your life searching for such a set of axioms. It also ended (or began, depending on your viewpoint, the "foundational crisis of mathematics"), which is a very interesting topic for another question.
There are also very interesting, closely related proofs that show that it is impossible to define truth inside a formal system (Tarski's Undefinability Theorem) and impossible to decide whether a given program with ever halt for a given input (Alan Turing's Halting Problem regarding algorithms/computation).
To answer your question: I am not familiar with formal definitions of the term "economics", but the term "formal system" (which the Incompleteness Theorem talks about) has a formal definition. So if you have a definition of "economics" which is based on a set of axioms and rules how to infer statements from those axioms (and other statements), and if it contains at least the integer numbers, then the IC applies.
Every practical field "escapes" the theorems anyways because none of these theorems tells anything about the usability of said formal systems, logics, or algorithms. In practice it does not matter whatsoever.
N.B., as the comments mention, things gets more ugly soon if you dig deeper; i.e. from these kinds of theorems you can deduce that it is impossible to do things in, say, software developement which would be very practical indeed, in this respect it is not really fair to say that all of them are just "theoretical".
• The inability to solve the Halting Problem is equivalent to Rice's Theorem, which really does muck things up we'd like to be able to do. And attempts to say "Rice's Theorem is only theoretical" ... doesn't pan out. Many of the fun things that Rice's Theorem says are impossible turn out to be impractical as well.
– Yakk
Sep 14 at 19:24
• True, I've added a little cop-out, @Yakk. Thanks for bringing that up.
– AnoE
Sep 15 at 8:42
Godel's incompleteness says that there is a dichotomy: A set of axioms is either complete or consistent, but not both.
If it is complete then you can prove any theorem from it but it will be inconsistent i.e. there will be paradoxes hidden somewhere.
If it is consistent there won't be paradoxes hidden in it but it will be incomplete i.e some theorems are not provable.
Is economics a "formal system of logic"?
It's a collection of empirical facts and a set of mathematical models build upon those facts. It might be a "formal system of logic" but that would be by accident.
In economics proving a theorem is not the criteria for whether the model is bad or good. What we really care about is whether the model is falsifiable and able to make predictions (we also care about the reproducibility of experiments).
Suppose that I came up with a new idea (theorem) and I want to know whether it's true: I don't really need to prove it, I only need to test it empirically then add the result to my list of known facts. If the result agrees with an already existing model then good for the model, it passed another test. If the result disagrees with an already existing model then bad for the model, it needs to be discarded or reformulated.
Proofs are still useful in economics (and all empirical sciences) because you still need to know whether the model is really what you meant:
Did you divide by zero somewhere? Did you assume a number was always positive when in reality it can be negative? Did you miss some parameter and now the model doesn't work in all circumstances you thought it would?
• I was going to write an answer to that effect, but you hit my main point better. All one has to do to escape the GIT is accept the notion that propositions can be true without being provable, and I doubt that any economist would seriously claim that all--or even most--true economic propositions could be proven. Sep 16 at 21:18
• accept the notion that propositions can be true without being provable that's a good way of putting it succinctly Sep 16 at 21:39
while also saying that empirical papers can reach the complete opposite conclusion with the same data
From a mathematical point of view, if your assumptions and logic lead to a contradiction, it means that, by reductio ad absurdum, there is a mistake somewhere.
You cannot use the corresponding theory anywhere, because it contains a contradiction, which means that false can be derived from it, and that this theory could be used to prove anything.
This is obviously a much larger problem (as mentioned by @VARulle) than having questions that cannot be answered (as stated by Gödel's incompleteness theorems).
Basically, if a contradiction appears somewhere, the whole theory needs to be rebuilt from scratch, and every assumption and logical step needs to be checked.
• Contradicting empirical conclusions are indeed problematic, but it would be unfortunate to confuse these with logical contradictions. Sep 14 at 15:54
• @Giskard: Yes. From what I understand about economics (not much), the models are often composed of a mathematical model + an interpretation of how it should be applied to the real world. The interpretation is a very important part of the model, and even with a correct mathematical basis, the interpretation can be flawed, or vary between school of thoughts. Sep 14 at 16:04
• The problem with this answer is that it doesn't address any of the three questions that the OP asked. Sep 14 at 20:47
Godel's theorems are about self-referencing statements of the form "This statement is unprovable by X" where 'X' is some system or mechanism for proving things. 'X' is usually some defined system of logic - a set of axioms and rules for proofs - but it doesn't have to be.
The basic idea is that if the statement is provable by X, then X can prove statements that are false, and so X is inconsistent. If X is consistent (only proves true statements) then the statement is unprovable by X, and therefore true. Godel's achievement was to encode both the statement and the proof system using only the methods of basic arithmetic applied to the positive whole numbers, thus showing (roughly speaking) that not every true arithmetical property of whole numbers can be proven.
Taken literally, it obviously doesn't apply to other systems like economics because economics isn't arithmetic. (Although arguably economics contains arithmetic...) But we can talk about a statement in the same spirit as Godel's theorems by asking whether "This statement cannot be proven in economics" is true or not?
If economics could prove it, economics would have proven something that is false, and so would be inconsistent. If economics cannot prove the statement, then the statement is true.
Various opinions could be had on that matter. Some would say economics is inconsistent ("empirical papers can reach the complete opposite conclusion with the same data"). Some would say it is incapable of providing proofs - only of inductively justifying increased or decreased belief. Some would ask "Which version of 'economics' are you talking about?" because there are many. Get any three economists together and you'll get four different opinions! And of course, some would say "Sure, but that's not really Godel's theorem."
What I don't think anyone would argue is to say that economics is both consistent (only proves true things) and can prove that the statement above can't be proved. Economists aren't that crazy! So in this sense, my view is that Godel's theorem applies just as powerfully to economics, too. It doesn't have the same significance, though, because nobody ever believed economics was complete and consistent, whereas lots of people held that belief about mathematics!
I would say you are getting into identifying a big issue in applied epistemology more generally namely that cross domain communication and knowledge transfer can be very hard which is to say that asking those trained in economics about the applicability of a mathematical proof to their domain is likely to yield unsatisfactory answers to the same degree that say, asking neurologists about the impact of some aspect of quantum physics is applicable to their understanding of neurological processes.
Sometimes even more worryingly the concepts may have been independently considered in two fields and while they conceptually discuss the same issues they may use entirely different vocabularies to describe this same concept. This occurs even amongst comparatively closely related fields of study like electrical and mechanical engineering. A particular example is that of control theory that spans these two fields and for various historical reasons have taken curious diverging paths at times.
That is not to say that the connections don't exist but the answers that make these questions interesting are not easy to come by as the concepts in each field can take significant study within the respective fields to even master and truly appreciate thus limiting the time available for experts from either field to really be able to discover the ideas from fields outside of their own even if there is considerable overlap never mind to meaningfully translate between the vocabularies to engage with those outside their field.
Is there a connection between the broad class of related ideas represented by the likes of Gödel's incompleteness theorems, Tarski's undefinability theorem, Church's answer to Hilbert's Entscheidungsproblem and finally and maybe more famously the Halting Problem, and more broadly all of human epistemology? I can't claim to be an expert in any of these specific proofs but I have to say there seems at least to me an intuitive sense in which this connection is unavoidable. They seem to point to some significant limits to what can and cannot be known and what it even means to know anything at all. Is the connection sometimes maybe overhyped and sensationalized a little by certain groups? Again I think the answer is yes but I think the resultant hesitancy in fields outside of those where these proofs first originated to investigate their consequences on their own fields is also a mistake as these are extremely significant and rigorous findings.
If highly simplified and formal systems are plagued with inherent contradictions, and computational limits then it does not bode well for larger more complex systems systems of knowledge. Sometimes practitioners unfamiliar with these proofs defend against this issue when first exposed to these ideas by making claims that these theoretical shortcomings do not translate to any limitations in practice but I would say that at the least computer science strongly refutes this proposition as the implications of the halting problem and other computability problems are quickly and trivially practical not least to massive economic consequence.
As for how these ideas have been addressed within economics I think there does feel like there are some similarities between the class of proofs previously listed and the Mises-Hayek economic calculation problem though I'm not familiar with any rigorous attempts to connect these ideas despite their passing similarities which as I initially mentioned seems related to the the difficulties encountered in sharing knowledge across domains.
I would therefore say that any attempt to reject the impact of this class of proofs on other fields is horribly misguided and smacks of significant doses of ignorance, but this must be weighed against the reality that in many practical fields the ability to make positive progress is not impeded by their applicability.
Not knowing and stated more strongly maybe never actually being able to know does not mean that significant value and progress cannot be achieved. After all, we aren't comparing the correctness and consistency of our knowledge systems to some system created by some perfect oracle somewhere but merely to those created by other humans similarly limited by the implications of these theories.
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http://mathhelpforum.com/calculus/60110-another-fundamental-theorem-calculus-problem.html
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# Thread: Another Fundamental Theorem of Calculus problem
1. ## Another Fundamental Theorem of Calculus problem
Does anyone know how to start or do this problem. I don't have an example in my book of it.
$\int_{-8}^ {6} f(x)= 2+e^x$
2. Originally Posted by McDiesel
Does anyone know how to start or do this problem. I don't have an example in my book of it.
Originally Posted by McDiesel
$\int_{-8}^ {6} f(x)= 2+e^x$
That is a nonsense problem. That is, it show the confusion of whom so ever wrote it
$\int_{-8}^ {6} f(x)$ is a definite integral, a number!
Whereas $2+e^x$ is a function of x.
Are you sure that you have given all the information?
3. I'm sorry,
Use a definite integral to find the area between $f(x)= 2+e^x$ and the x-axis over the integral [-8,6]
4. Originally Posted by McDiesel
I'm sorry,
Use a definite integral to find the area between $f(x)= 2+e^x$ and the x-axis over the integral [-8,6]
This is very simple since $\forall{x}\in\mathbb{R}~2+e^x>0$
So $\text{Area}=\int_{-8}^{6}2+e^xdx$
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http://www.freshports.org/textproc/p5-TeX-Encode/
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976b FreshPorts -- textproc/p5-TeX-Encode
I am looking for an LTO tape library. Do you have one to spare?
Port details p5-TeX-Encode 1.3 textproc =0 Encode/decode Perl utf-8 strings into TeX Maintained by: [email protected] Port Added: 15 May 2006 16:45:09 Also Listed In: perl5 License: not specified in port This module provides encoding to LaTeX escapes from utf8 using mapping tables in Pod::LaTeX and HTML::Entities. This covers only a subset of the Unicode character table (undef warnings will occur for non-mapped chars). Mileage will vary when decoding (converting TeX to utf8), as TeX is in essence a programming language, and this module does not implement TeX. I use this module to encode author names in BibTeX and to do a rough job at presenting LaTeX abstracts in HTML. Using decode rather than seeing $\sqrt{\Omega^2\zeta_n}$ you get something that looks like the formula. The next logical step for this module is to integrate some level of TeX grammar to improve the decoding, in particular to handle fractions and font changes (which should probably be dropped). WWW: http://search.cpan.org/dist/TeX-Encode/SVNWeb : Main Web Site : Distfiles Availability : PortsMonNOTE: FreshPorts displays only required dependencies information. Optional dependencies are not covered.Required To Build: Required To Run: This port is required by:for Build for Run * - deleted ports are only shown under the This port is required by section. It was harder to do for the Required section. Perhaps later... To install the port: cd /usr/ports/textproc/p5-TeX-Encode/ && make install cleanTo add the package: pkg install textproc/p5-TeX-Encode Configuration Options No options to configure Master Sites:
Number of commits found: 24
Commit History - (may be incomplete: see SVNWeb link above for full details) Date By Description 07 Nov 2013 03:52:42 1.3 vanilla Support STAGEDIR. 20 Sep 2013 23:17:32 1.3 bapt Add NO_STAGE all over the place in preparation for the staging support (cat: textproc) 29 Aug 2013 17:16:53 1.3 sunpoet - Add WWW - Use single space after WWW: - Remove Author line 02 Aug 2013 18:52:11 1.3 mat - Convert to new perl framework - Trim Makefile header - Remove MAKE_JOBS_SAFE=yes, it's the default. 05 Mar 2012 20:46:34 1.3 swills - Oops, wrong TEST_DEPENDS in previous commit, needs p5-Test-Pod-Coverage, not p5-Pod-Coverage 05 Mar 2012 20:31:02 1.3 swills - Add TEST_DEPENDS to enable testing 28 Dec 2011 08:20:20 1.3 ehaupt End WWW CPAN URL with a "/" 15 Nov 2011 16:51:20 1.3 sunpoet - Document minimal required version of dependency - Cosmetic change Feature safe: yes 24 Oct 2011 09:11:38 1.3 dougb The vast majority of pkg-descr files had the following format when they had both lines: Author: ... WWW: .... So standardize on that, and move them to the end of the file when necessary. Also fix some more whitespace, and remove more "signature tags" of varying forms, like -- name, etc. s/AUTHOR/Author/ A few other various formatting issues 23 Sep 2011 13:23:20 1.3 culot - Update to 1.3 Changes: http://search.cpan.org/dist/TeX-Encode/Changes 17 Sep 2011 06:49:29 1.1 sunpoet - Change PERL_CONFIGURE to "yes" for all values less than or equal to 5.8.0+ With hat: perl 20 Jun 2011 09:03:27 1.1 az - Replace ../../authors in MASTER_SITE_SUBDIR with CPAN:CPANID macro. See http://wiki.freebsd.org/Perl for details. - Change maintainership from ports@ to perl@ for ports in this changeset. - Remove MD5 checksum 17 May 2011 11:13:00 1.1 jadawin - Cleaning MD5 in perl@'s ports Approved by: erwin@ (portmgr) 29 Apr 2008 11:18:49 1.1 miwi - Update to 1.1 - Pass maintainership to perl 29 Apr 2008 05:27:10 0.9 linimon Reset aaron's port maintainerships due to many maintainer-timeouts. 17 Apr 2008 14:30:31 0.9 araujo - Take advantage of CPAN macro from bsd.sites.mk, change \${MASTER_SITE_PERL_CPAN} to CPAN. PR: ports/122674 Submitted by: Philip M. Gollucci Reworked by: araujo (myself) Approved by: portmgr (pav) 08 Sep 2007 01:06:22 0.9 linimon Welcome bsd.perl.mk. Add support for constructs such as USE_PERL5=5.8.0+. Drop support for antique perl. Work done by: gabor Sponsored by: Google Summer of Code 2007 Hat: portmgr 15 Jun 2007 16:17:23 0.9 aaron Bump version number to make fetchable. Old distfiles removed. PR: 111293 Submitted by: [email protected] 11 Mar 2007 09:10:08 0.8_1 kris BROKEN: Unfetchable 18 Feb 2007 13:17:52 0.8_1 gabor - Remove broken and useless dependency. This dependency is part of Perl >=5.6, and we don't suppot lower Perl versions any more. This change makes this port usable again. - Trim duplicated dependency - Bump PORTREVISION Approved by: maintainer inactivity (aaron), erwin (mentor) 26 Dec 2006 21:28:11 0.8 aaron Update to v0.08 07 Dec 2006 16:18:27 0.6 laszlof - it would appear as though pod2latex comes bundled with lang/perl5.8, so the textproc/p5-Pod-LaTeX dependancy can be removed PR: ports/104986 Submitted by: Thomas Abthorpe Approved by: maintainer timeout (5 weeks) 16 May 2006 18:58:17 0.6 aaron - Updated from v0.4 to v0.6 0.6 - Fixed incompatibility with HTML::Parser 1.35 - Upped the required versions of Pod::LaTeX and HTML::Entities to ones I know work 0.5 - Fixed an incorrect quoting bug in MathMode - Added a couple of tests for quote bug and escaping - Now unescapes any singular character (\\ => \, \x => x, etc), this may be too broad and need casing? Approved by: tobez (implicit) 15 May 2006 16:39:18 0.4 aaron Adding port textproc/p5-TeX-Encode, Encode/decode Perl utf-8 strings into TeX Approved by: tobez (implicit)
Number of commits found: 24
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https://pureportal.strath.ac.uk/en/publications/toward-understanding-myometrial-regulation-metabolomic-investigat
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Toward understanding myometrial regulation: metabolomic investigation reveals new pathways of oxytocin and ritodrine activity on the myometrium
Research output: Contribution to journalArticlepeer-review
9 Citations (Scopus)
Abstract
In recent times, additional pathways involved in the regulation of the myometrium have been suggested. This also holds true for the effect of drugs such as oxytocin (OT) and β-adrenergic agonists on the myometrium. Knowledge of these additional pathways will certainly prove useful in designing better therapies for pathologies of the myometrium. This study was therefore aimed at investigating the possibility of other pathways involved in the activities of both OT and ritodrine (RIT; a β-adrenergic agonist) in the myometrium by utilizing metabolomics and bioinformatics. High-resolution Fourier transform mass spectrometry (HRFTMS) and nuclear magnetic resonance (NMR) spectroscopy coupled with functional uterine assays were used for an innovative assessment. In vitro pharmacological assay of OT (1 nmol/L) and RIT (0.1 nmol/L) on isolated mice uteri mounted in 3 mL organ baths was performed. Mice uteri, treated with OT or RIT, as well as the physiological buffer in which the uterine tissues were immersed, were rapidly collected and analyzed using HRFTMS, proton ((1)H)-NMR, and bioinformatics. Resulting data were analyzed via pairwise chemometric comparison models, with P ≤ .05 considered statistically significant. In addition to previously known metabolites, nicotinamide adenine dinucleotide, γ-aminobutyric acid, and sphingosine were significantly associated with the activity of OT, whereas the activity of RIT was associated with a downstream involvement of prostaglandin F1 and phosphatidylinositol signaling. These findings add evidence to the reports on additional regulation of myometrial activity by these drugs and suggest newer pathways for therapeutic manipulation.
Original language English 15 Reproductive Sciences 27 Sep 2016 https://doi.org/10.1177/1933719116667224 E-pub ahead of print - 27 Sep 2016
Keywords
• uterus
• oxytocin
• ritodrine
• reproductive pharmacology
• metablomics
• bioinformatics
• myometrium
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https://www.physicsforums.com/threads/twin-paradox-again-yes-again.165370/
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# Twin paradox again (yes again)
1. Apr 12, 2007
### OS Richert
There is a simple truth to this world. Some people are dumb. I am one of them. I'm sorry to ask this but yet again but I just don't get it. Here is the latest explanation of the twin paradox that I have read.
http://mentock.home.mindspring.com/twins.htm" [Broken]
I understand the three reference frames concept. I just don't understand why "Bob" in this case must be the one who switches reference frames. Let me quote one section
EXACTLY EXACTLY EXACTLY. We just restate the problem with the names reversed. But why can't Bob do that. Why can't Bob says, "Heck No! I'm not switching reference frames! I'm not chasing after the wench at 15/17 the speed of light. I'm sitting right here in my rest frame and letting HER turn around and come back at 3/5c. And when she does, I'LL be younger. As far as I'm concerned, in Bob's eyes Ann darted off at 3/5c and darted back at 3/5c and he just sat there the whole time. The only difference is that he also saw the earth dart away and dart back at the same speed. She can switch reference frames all she wants but Bob is keeping his.
If we CAN"T let Ann switch reference frames but that would just restate the problem, then there is some sense in which Bob really must be the one moving or must be the one who turned around. He is always the one getting older!
What am I missing? Will this misery never end!!!
Last edited by a moderator: May 2, 2017
2. Apr 12, 2007
### JesseM
Bob can't say that because when Bob accelerates, he'll feel G-forces which tell him he's not moving inertially. If Ann was the one who turned around, Ann would be the one to feel the G-forces, while Bob would be weightless from beginning to end.
You can certainly let Ann switch reference frames--she just has to accelerate in the direction of Bob, so that after the acceleration the distance between her and Bob is decreasing rather than increasing. In this case it will be Ann, not Bob, who is younger when they reunite (assuming Bob did not also accelerate). But again, this will be different than the case where Bob turns around because Ann will feel the G-forces during acceleration while Bob will be weightless throughout.
3. Apr 12, 2007
### Staff: Mentor
Reference frames in general are a mathematical concept. Inertial reference frames also have physical significance. Newton's First Law of Motion is basically a statement that inertial reference frames exist, and have special physical status.
4. Apr 12, 2007
### OS Richert
Okay, so even though we made this acceleration instintaneous, it is still the determing factor. It is not a question of relative motion but whoever actually experiences a force to change the relative motion between them, this one will be younger
5. Apr 12, 2007
### Antman
Does SR include math on how to add speeds? Obviously I havn't read the SR but I would like too. Where can I find Einsteins original formulation and math and whatever he publiced when he announced SR?
6. Apr 12, 2007
### Robert J. Grave
The change in direction and the resulting accelleration is relative to the mass of the entire universe not just between the twins so which one ages is the one accelerating. If two cars are traveling side by side and one steps on the gas and speeds away it's that cars occupants that feel the accelleration. Motion is relative but not accelleration. Remember that inertia and gravity are one and the same thing. -Robert.
7. Apr 12, 2007
### JesseM
Basically this is right, although keep in mind that if Bob is moving away from Earth at 0.8c, then briefly accelerates towards the Earth, then immediately accelerates away again until he's once again moving away from Earth at 0.8c, and then later Ann accelerated towards Bob and eventually catches up with him, then Ann will still be younger, and by almost exactly the same amount as if Bob had not accelerated at all.
Personally, I think the best way to think of it is in terms of the geometry of the two worldlines. As an analogy, if you draw two paths connecting the same two points on an ordinary sheet of paper, one a straight line and the other with one or more bends in it, the straight line will always be the shortest one. You could even calculate the lengths of each path using different coordinate systems analogous to reference frames--draw an x and y axis, and then calculate how much the length of each path increases with each increment of the y axis (if a path is parallel to the y-axis from y=4 to y=6, then the path length will only have increased by 2 over that increment, but if the path has a slope of 2 from y=4 to y=6, meaning that it increments 1 in the x direction for every increment of 2 in the y-direction, then from y=4 to y=6 the path length will have increased by $$\sqrt{1^2 + 2^2} = \sqrt{5}$$ over the same interval). But even if you choose a number of different orientations for the y and x axis and recalculate the path length in each coordinate system using this same method, you'll always find that the straight-line path is shorter than a bent path between the same two points. In the same way, the geometry of spacetime is such that a straight worldline always has a greater proper time than a "bent" one (any worldline involving acceleration). And the case where Bob accelerates twice, returning to his initial velocity after the second acceleration, is analogous to a line that has one bend that sends it in a different direction, but then shortly after that another bend which returns it to its original direction--this path's length will only be slightly different from the length of a straight line path between the same two points.
8. Apr 12, 2007
### JesseM
That would be true if [URL [Broken] principle[/url] were valid, but neither special relativity nor general relativity is truly "Machian" in this sense--the theories would allow you to have a totally empty universe apart from two test particles of infinitesimal mass, and it would still be true that whichever particle accelerates will have elapsed less time.
Last edited by a moderator: May 2, 2017
9. Apr 12, 2007
### JesseM
Yes, see here.
You can find it here, but I wouldn't recommend this as a starting point for learning SR, more modern presentations would have proofs that are easier to follow along with useful aides that were developed later like spacetime diagrams, and more explanation of the background of Einstein's thinking like the problems physicists at the time were having understanding Maxwell's laws.
10. Apr 12, 2007
### Staff: Mentor
In general, the original presentation of any well-established theory is not the best place to start learning the theory from scratch, although it may be interesting and worthwhile to study it after you're already fairly fluent in that theory.
After all, how many people learn classical mechanics from scratch using Newton's "Principia Mathematica?" :uhh:
11. Apr 13, 2007
### Antman
Thanks for the answers and th link! What is really interesting is what information Einstein had at the time when he thought up his special relativity theory and to follow the road his mind took from previous knowledge to SR.
The problem this thread discusses seems flaud in that way it says the twin paradox has nothing to do with acceleration.
12. Apr 13, 2007
### JesseM
Who on this thread has said it has nothing to do with acceleration? I didn't say that.
13. Apr 13, 2007
### MeJennifer
The twin "paradox" has everything to do with acceleration.
Note though, that it is, in principle, possible to have a time interval differential for inertial twins in curved spacetime. Spacetime curvature can separate them and bring them back together, their elapsed time could be different even while both stay inertial the whole time.
But this is impossible in flat spacetime.
Last edited: Apr 13, 2007
14. Apr 14, 2007
### Antman
Sorry, noone in this thread said that. It was the problem in the link that did.
It seems everyone here agrees acceleration is what makes travelling twin younger but the problemformulation in the link says it does not have to do with accelleration. Or am I missreading totally?
15. Apr 14, 2007
### sylas
It is not that acceleration "makes the twin younger". To think in such terms goes right back to the notion of some absolute reference from against which you decide who is younger. It is rather that acceration shows that you are not in an inertial reference frame.
16. Apr 14, 2007
### JesseM
I don't think that quote is saying it has nothing to do with acceleration, just that you don't have to have a "treatment" of either how things look in an accelerating frame of reference, or of how the ship's clock is dilating during the acceleration phase; instead you can just make the acceleration instantaneous, and then add the time elapsed on the outbound leg of the trip and the time elapsed on the inbound leg (both of which are inertial) to find the total time elapsed on the travelling twin's clock between leaving Earth and returning.
17. Apr 14, 2007
### pervect
Staff Emeritus
If you consider the space-time diagram of a twins paradox type experiment, you can see that the twins form a triangle.
Acceleration means that the triangle isn't perfect, that the points of the triangle are actually slightly rounded by the acceleration.
However, this can be made to be a very small effect, by taking the limit of high accelerations.
What the twin paradox says is very similar to the geometrical theorem that the shortest distance between two points is a straight line, or eqivalently, the "triangle inequality" that says that the sum of the length of two sides of a triangle is always longer than the remaining third side.
In the case of the twins paradox, though, the statement becomes that the observer following a geodesic path (analogous to the straight line, especially in the flat geometry of SR) has the longest proper time. The time is the longest, but the distance in the Euclidean geometrical analogy is the shortest. This has to do with the difference between Euclidean geometry with it's ++++ metric signature, and the Lorentzian geomery of SR with it's -+++ signature.
Acceleration (the curvature at the tips of the triangle) really has very little to do with this geometrical result.
That is why people say that the twin paradox isn't about the rounding of the corners due to the acceleration - it's due to the angle between the observers. This angle on a space-time diagram is simply a change of velocity. What is important is not the rate at which the velocity changes (the accleration) , but what is often called "delta-V", the change in velocity.
The geometrical analogy of the "twins pardox" would be the "triangle paradox". The triangle paradox would say:
If I go directly from A to B, I travel the shortest distance. And if I go from A to C to B, I travel a longer distance. It's "paradoxical" (?) that when I go from A to C to B, that this distance is longer than going straight from A to B. Furthermore, if I look at the distance from A to B, that's shorter than going from A to C to B. Now AB is the shortest distance!
Of course people gemerally don't get confused by the "triangle paradox" - it's really not that much more difficult not to get confused by the "twin paradox" either.
Last edited: Apr 14, 2007
18. Apr 14, 2007
### Robert J. Grave
It's not that accelleration does not occur, it's that it's value is not important but the fact that it, the accelleration, results in the creation of another inertial frame and a time differance. So do you need the actual rate of acceleration to find the time difference value? -Robert.
19. Apr 15, 2007
### MeJennifer
The longest or, more accurately, the extremal path in spacetime is a geodesic and records the largest proper time.
In flat spacetime extremal length of a world line is an indicator of straightness.
Last edited: Apr 15, 2007
20. Apr 15, 2007
### OS Richert
The best guess I have is that acceleration only matters in that it is necessary in order for Bob to change inertial frames. The actual period in acceleration can be made arbitrarily small and does not factor into the actual time calculation. My original concern was that since we were making acceleration instantaneous, that for both Bob and Anne the experience truly would be identical; while they are sitting still, the other party blasts off, then returns. But in reality, one of them DID have to change frames in order for this to happen, and in this example it was Bob who was assigned to truly change frames. And he changed Frames because he actually experienced acceleration; even though we made it so fast that the time period he was actually accelerating did not factor into the calculation.
21. Apr 15, 2007
### Robert J. Grave
After the time deration of the accelleration periods, there is no time dillation since linier motion does not produce durrable time dillation just as in SR. So it seems that the accelleration values must be required to determine the actual time difference the twins will experiance. -Robert.
22. Apr 15, 2007
### JesseM
What do you mean by "linear motion does not produce durable time dilation"? If you're traveling at some constant velocity v relative to me, then in my frame your clock will be slowed down by a constant amount, no?
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http://elsenaju.eu/Determinant/Vector-Calculation.htm
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# Vector Calculus
## History of vector calculation
The vector calculus goes back to H. G. Grassmann and parallel to Hamilton. Grassmann published in 1844 the "Lineale Ausdehnungslehre". As a precursor Descartes and Möbius apply. The Irish mathematician William Rowan Hamilton (1805 - 1865) developed the theory of quaternions, which are considered as precursors of the vectors. The term scalar goes back to Hamilton. 1888 the Italian mathematician Giuseppe Peano (1858-1932) developed an axiomatic definition of a vector space.
## Scalar
Quantities that can be represented by a real number. Examples for scalar values are temperature, mass, ...
## Vector
Vectors, in addition to its value require the specification of a direction. In physics, e.g. Velocity, field strength, ... In general, a vector is not limited to three dimensions. In general it is an n-tuple of real numbers that is often listed as a column vector.
$\stackrel{\to }{v}=\left(\begin{array}{c}{\mathrm{v1}}_{}\\ {v}_{2}\\ ⋮\\ {v}_{n}\end{array}\right)$
## Linear Dependence
Two vectors are called linearly dependent or collinear if one can be converted by multiplication by a scalar in the other. The cross product of collinear vectors disappears.
## Orthogonality
Two vectors are called orthogonal if the dot product of two vectors vanishes. Geometrically, the vectors are perpendicular to each other then that is the angle enclosed by the vectors is 90°.
## Unit vector
Vectors of length 1 are called unit vectors. Each vector can be converted by normalizing into the unit vector by the vector is divided by its length.
## Calculation rules for vectors
### Multiplication of a vector with a scalar
The multiplication of a vector by a scalar positive λ only changes the length of the vector and not direction. In the multiplication with a scalar, the negative direction of the vector changes in the opposite direction.
${\lambda }\cdot \stackrel{\to }{v}=\left(\begin{array}{c}{\lambda }\cdot {v}_{1}\\ {\lambda }\cdot {v}_{2}\\ ⋮\\ {\lambda }\cdot {v}_{n}\end{array}\right)$
For the multiplication of a vector by a scalar λ the distributive law holds.
${\lambda }\cdot \left(\stackrel{\to }{v}+\stackrel{\to }{w}\right)={\lambda }\cdot \stackrel{\to }{v}+{\lambda }\cdot \stackrel{\to }{w}$
The addition of vectors is done in Cartesian coordinates componentwise. The vector addition is commutative and associative.
$\stackrel{\to }{v}+\stackrel{\to }{w}=\left(\begin{array}{c}{v}_{1}\\ {v}_{2}\\ ⋮\\ {v}_{n}\end{array}\right)+\left(\begin{array}{c}{w}_{1}\\ {w}_{2}\\ ⋮\\ {w}_{n}\end{array}\right)=\left(\begin{array}{c}{v}_{1}+{w}_{1}\\ {v}_{2}+{w}_{2}\\ ⋮\\ {v}_{n}+{w}_{n}\end{array}\right)$
Geometrically, the resulting vector can be constructed by one of the vectors is parallel shifted to the other end point of the vector. The connection from the start point of the first vector to the end point of the second vector is the resultant of vector of vector addition.Graphical vector addition
### Subtraction of vectors
Subtraction of vectors is carried out as by the addition of the components are subtracted.
$\stackrel{\to }{v}-\stackrel{\to }{w}=\left(\begin{array}{c}{v}_{1}\\ {v}_{2}\\ ⋮\\ {v}_{n}\end{array}\right)-\left(\begin{array}{c}{w}_{1}\\ {w}_{2}\\ ⋮\\ {w}_{n}\end{array}\right)=\left(\begin{array}{c}{v}_{1}-{w}_{1}\\ {v}_{2}-{w}_{2}\\ ⋮\\ {v}_{n}-{w}_{n}\end{array}\right)$
Geometrically, the construction similar to the addition of only the vector will be mirrored to the negative sign in the direction.Graphical vector subtraction
### Dot Product (inner Product) of vectors
The dot product is defined as the product of the components and the sum of these products. The scalar product is not of the order-dependent (commutative). The scalar product name comes from the fact that the result is a scalar and not a vector.
$\stackrel{\to }{v}\cdot \stackrel{\to }{w}=\left(\begin{array}{c}{v}_{1}\\ {v}_{2}\\ ⋮\\ {v}_{n}\end{array}\right)\cdot \left(\begin{array}{c}{w}_{1}\\ {w}_{2}\\ ⋮\\ {w}_{n}\end{array}\right)$ $={v}_{1}\cdot {w}_{1}+{v}_{2}\cdot {w}_{2}+\dots +{v}_{n}\cdot {w}_{n}$$=\sum _{i=1}^{n}\left({v}_{i}\cdot {w}_{i}\right)$
The scalar product can be interpreted as the product of the geometric projection of a vector in the direction of the other vector. Physically it means that the product is formed only with the Kompnente of the vector that is effective in the direction of another vector.
The scalar product can be expressed geometrically. Here, φ the included angle of the vectors.Graphical inner product
$\stackrel{\to }{v}\cdot \stackrel{\to }{w}=|\stackrel{\to }{v}||\stackrel{\to }{w}|\mathrm{cos}\phi$
For the scalar product of the distributive law apply
$\stackrel{\to }{u}\cdot \left(\stackrel{\to }{v}+\stackrel{\to }{w}\right)=\stackrel{\to }{u}\cdot \stackrel{\to }{v}+\stackrel{\to }{u}\cdot \stackrel{\to }{w}$
and the commutative law
$\stackrel{\to }{v}\cdot \stackrel{\to }{w}=\stackrel{\to }{w}\cdot \stackrel{\to }{v}$
Dot Product calculator for vectors with 3 components.
$\stackrel{\to }{v}\cdot \stackrel{\to }{w}=\left(\begin{array}{c}{v}_{1}\\ {v}_{2}\\ {v}_{3}\end{array}\right)\cdot \left(\begin{array}{c}{w}_{1}\\ {w}_{2}\\ {w}_{3}\end{array}\right)$
Input fields for the vector elements.
v1= w1=
v2= w2=
v3= w3=
### Length of a vector
The magnitude of a vector geometrically corresponds to the length of the vector.
$\left|\stackrel{\to }{v}\right|=$ $|$ $\left(\begin{array}{c}{v}_{1}\\ {v}_{2}\\ ⋮\\ {v}_{n}\end{array}\right)$ $|$$=\sqrt{{v}_{1}^{2}+{v}_{2}^{2}+\dots +{v}_{n}^{2}}$$=\sqrt{\sum _{i=1}^{n}{v}_{i}^{2}}$
Calculator for the length of a vector with 3 components.
$|$ $\stackrel{\to }{v}$ $|$ $=$ $|$ $\left(\begin{array}{c}{v}_{1}\\ {v}_{2}\\ {v}_{3}\end{array}\right)$ $|$
Input fields for the vector elements.
v1=
v2=
v3=
### Cross Product (outer product) of vectors
The vector product is defined in three-dimensional Euclidean vector space as follows.
$\stackrel{\to }{v}\cdot \stackrel{\to }{w}=\left(\begin{array}{c}{v}_{1}\\ {v}_{2}\\ {v}_{3}\end{array}\right)⨯\left(\begin{array}{c}{w}_{1}\\ {w}_{2}\\ {w}_{3}\end{array}\right)$$=\left(\begin{array}{c}{v}_{2}{w}_{3}-{v}_{3}{w}_{2}\\ {v}_{1}{w}_{3}-{v}_{3}{w}_{1}\\ {v}_{1}{w}_{2}-{v}_{2}{w}_{1}\end{array}\right)$
The vector product provides as a result a vector which is perpendicular to the plane spanned by the two vectors and the length of which corresponds to the surface area of the clamped parallelogram.
The cross product can be expressed geometrically. Here, φ the included angle of the vectors and n is the vector perpendicular to the surface.
$v→⨯w→= |v→||w→|sinφn→$
The vector product is anti-commutative
$v→⨯w→ = -w→⨯v→$
Cross Product calculator for vectors with 3 components.
$\stackrel{\to }{v}\cdot \stackrel{\to }{w}=\left(\begin{array}{c}{v}_{1}\\ {v}_{2}\\ {v}_{3}\end{array}\right)⨯\left(\begin{array}{c}{w}_{1}\\ {w}_{2}\\ {w}_{3}\end{array}\right)$
Input fields for the vector elements.
v1= w1=
v2= w2=
v3= w3=
### Multiplication of a vector with a matrix
The product of a matrix by a vector is a linear mapping. Explains the multiplication when the number of columns of the matrix is equal to the number of elements of the vector. The result is a vector whose number of components equal to the number of rows of the matrix. That the example a matrix with two rows a vector always maps to a vector with two components.Graphical Matrix-Vector produkt
$A\cdot \stackrel{\to }{v}=\left(\begin{array}{cccc}{a}_{11}& {a}_{12}& \dots & {a}_{1m}\\ {a}_{21}& {a}_{22}& \dots & {a}_{2m}\\ & ⋮\\ {a}_{n1}& {a}_{n2}& \dots & {a}_{nm}\end{array}\right)\cdot \left(\begin{array}{c}{v}_{1}\\ {v}_{2}\\ ⋮\\ {v}_{m}\end{array}\right)=$
$\left(\begin{array}{c}{a}_{11}{v}_{1}+{a}_{12}{v}_{2}+\dots +{a}_{1m}{v}_{m}\\ {a}_{21}{v}_{1}+{a}_{22}{v}_{2}+\dots +{a}_{2m}{v}_{m}\\ ⋮\\ {a}_{n1}{v}_{1}+{a}_{n2}{v}_{2}+\dots +{a}_{nm}{v}_{m}\end{array}\right)$
## Multiple products
Multiple products of vectors are not associative in general. That the general rule is that the order in which the products are carried out is relevant.
In general is:
$\stackrel{\to }{u}\cdot \left(\stackrel{\to }{v}\cdot \stackrel{\to }{w}\right)\ne \left(\stackrel{\to }{u}\cdot \stackrel{\to }{v}\right)\cdot \stackrel{\to }{w}$
and
$\stackrel{\to }{u}⨯\left(\stackrel{\to }{v}⨯\stackrel{\to }{w}\right)\ne \left(\stackrel{\to }{u}⨯\stackrel{\to }{v}\right)⨯\stackrel{\to }{w}$
For the double vector product the development applies:
$\stackrel{\to }{u}⨯\left(\stackrel{\to }{v}⨯\stackrel{\to }{w}\right)=\stackrel{\to }{v}\cdot \left(\stackrel{\to }{u}\cdot \stackrel{\to }{w}\right)-\stackrel{\to }{w}\cdot \left(\stackrel{\to }{u}\cdot \stackrel{\to }{v}\right)$
The scalar triple product $\left(\stackrel{\to }{u}⨯\stackrel{\to }{v}\right)\cdot \stackrel{\to }{w}$ is equal to the volume of the plane defined by the three vectors parallelepiped. The scalar triple product is positive if the three vectors form a right hand system.
Lagrangesche Identity:
$\left(\stackrel{\to }{m}⨯\stackrel{\to }{u}\right)\cdot \left(\stackrel{\to }{v}⨯\stackrel{\to }{w}\right)$$=\left(\stackrel{\to }{m}\cdot \stackrel{\to }{v}\right)\left(\stackrel{\to }{u}\cdot \stackrel{\to }{w}\right)-\left(\stackrel{\to }{u}\cdot \stackrel{\to }{v}\right)\left(\stackrel{\to }{m}\cdot \stackrel{\to }{w}\right)$
## Geometrical approches
Equation of the line through the two points P0 und P1 given by the vectors r0 und r1:
$\stackrel{\to }{r}=\stackrel{\to }{{r}_{0}}+\lambda \left(\stackrel{\to }{{r}_{1}}-\stackrel{\to }{{r}_{0}}\right)$
Distance of two points P0 and P1:
$\left|\stackrel{\to }{{r}_{1}}-\stackrel{\to }{{r}_{0}}\right|$
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http://mathhelpforum.com/advanced-math-topics/134219-complex-analysis-print.html
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# complex analysis
• March 16th 2010, 11:53 PM
Kat-M
complex analysis
Let $\gamma$: [0,1] $\rightarrow C$ be any $C^1$ curve. Define $f(z)=\oint_{\gamma} \frac{1}{\zeta-z}d\zeta$
Prove that $f$ is holomorphic on $C$\ $\tilde{\gamma}$, where $\tilde{\gamma}=\{ \gamma (t):0\leq t \leq 1\}.$
• September 12th 2010, 09:43 PM
Rebesques
You can compute the difference quotient $[f(z+w)-f(z)]/w$ as $w\rightarrow 0$. The limit is (what a surprise) $f'(z)=-\int_{\gamma} \frac{1}{(\zeta-z)^2}d\zeta$.
ps. what's with the \oint? I believe that notation is,
only to signify counter-clockwise integration along a closed curve (Thinking)
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https://www.gradesaver.com/textbooks/math/applied-mathematics/elementary-technical-mathematics/chapter-10-section-10-3-finding-binomial-factors-exercise-page-350/67
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## Elementary Technical Mathematics
$3x(y-3)^2$
$3xy^2-18xy+27x\longrightarrow$ 3x is a common factor. $3x(y^2-6y+9)$ =$3x(\ \ \ \ \ \ \ \ \ )(\ \ \ \ \ \ \ \ \ )$ =$3x(y\ \ \ \ \ \ \ )(y\ \ \ \ \ \ \ )$ =$3x(y-\ \ )(y-\ \ )$ Since the 2nd term is negative and the 3rd is positive, the factors of 9 must both be negative. =$3x(y-3)(y-3)$ -3 and -3 have a sum of -6 and a product of 9. Since $y-3$ is repeated as a factor it is written as an exponent.
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http://clay6.com/qa/36036/www.clay6.com/qa/36036/transpiration-occurs-from
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# Transpiration occurs from
$\begin{array}{1 1}(A)\;\text{Leaves}\\(B)\;\text{Stem} \\(C)\;\text{All aerial parts}\\(D)\;\text{Roots}\end{array}$
Transpiration occurs from all aerial parts.
Hence (C) is the correct answer.
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https://www.groundai.com/project/super-chandrasekhar-mass-light-curve-models-for-the-highly-luminous-type-ia-supernova-2009dc/
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Super-Chandrasekhar-Mass LC Models for SN 2009dc
# Super-Chandrasekhar-Mass Light Curve Models for the Highly Luminous Type Ia Supernova 2009dc
Yasuomi Kamiya11affiliation: Department of Astronomy, Graduate School of Science, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. 22affiliation: Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, the University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583, Japan. 77affiliation: Research Fellow of the Japan Society for the Promotion of Science. Masaomi Tanaka33affiliation: National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan. 22affiliation: Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, the University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583, Japan. Ken’ichi Nomoto22affiliation: Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, the University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583, Japan. 11affiliation: Department of Astronomy, Graduate School of Science, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. Sergei I. Blinnikov44affiliation: Institute for Theoretical and Experimental Physics, 117218 Moscow, Russia. 55affiliation: Sternberg Astronomical Institute, Lomonosov Moscow State University, 119992 Moscow, Russia. 22affiliation: Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, the University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583, Japan. Elena I. Sorokina55affiliation: Sternberg Astronomical Institute, Lomonosov Moscow State University, 119992 Moscow, Russia. 22affiliation: Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, the University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583, Japan. Tomoharu Suzuki66affiliation: College of Engineering, Chubu University, 1200 Matsumoto-cho, Kasugai, Aichi 487-8501, Japan. 11affiliation: Department of Astronomy, Graduate School of Science, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
###### Abstract
Several highly luminous Type Ia supernovae (SNe Ia) have been discovered. Their high luminosities are difficult to explain with the thermonuclear explosions of the Chandrasekhar-mass white dwarfs (WDs). In the present study, we estimate the progenitor mass of SN 2009dc, one of the extremely luminous SNe Ia, using the hydrodynamical models as follows. Explosion models of super-Chandrasekhar-mass (super-Ch-mass) WDs are constructed, and multi-color light curves (LCs) are calculated. The comparison between our calculations and the observations of SN 2009dc suggests that the exploding WD has a super-Ch mass of 2.2–2.4 , producing 1.2–1.4 of Ni, if the extinction by its host galaxy is negligible. If the extinction is significant, the exploding WD is as massive as 2.8 , and 1.8 of Ni is necessary to account for the observations. Whether the host-galaxy extinction is significant or not, the progenitor WD must have a thick carbon-oxygen layer in the outermost zone (20–30% of the WD mass), which explains the observed low expansion velocity of the ejecta and the presence of carbon. Our estimate on the mass of the progenitor WD, especially for the extinction-corrected case, is challenging to the current scenarios of SNe Ia. Implications on the progenitor scenarios are also discussed.
supernovae: individual (SN 2009dc) — radiative transfer — white dwarfs
slugcomment: Accepted for publication in ApJ on July 18, 2012.
## 1. Introduction
It has been widely accepted that a Type Ia supernova (SN Ia) results from a thermonuclear explosion of a carbon-oxygen (C+O) white dwarf (WD) in a close binary system. The most likely model is that the explosion is triggered by carbon ignition in the central region of the WD when the WD mass () reaches the critical mass (, 1.38 for a non-rotating C+O WD; e.g., Hillebrandt & Niemeyer, 2000; Nomoto et al., 1997, 2000). Since is very close to the Chandrasekhar’s limiting mass (Chandrasekhar mass, )111 Hereafter denotes the Chandrasekhar’s limiting mass for a non-rotating C+O WD, i.e., , where is the electron mole fraction (e.g., Chanrdasekhar, 1939)., the resulting explosions are expected to have similar properties. Actually, normal SNe Ia are used as standard candles in cosmology (Riess et al., 1998; Perlmutter et al., 1999), after correcting their luminosity dispersion by using the Pskovskii-Phillips relation (e.g., Pskovskii, 1977; Phillips, 1993).
Despite their uniformity, several unusual SNe Ia have been found to be much more luminous than normal ones. They are SN 2003fg (Howell et al., 2006), SN 2006gz (Hicken et al., 2007), SN 2007if (Scalzo et al., 2010; Yuan et al., 2010), and SN 2009dc (Yamanaka et al., 2009; Tanaka et al., 2010; Silverman et al., 2011; Taubenberger et al., 2011). These SNe Ia all show slow luminosity evolutions (e.g., Scalzo et al., 2010, Table 4). Three of them, except for SN 2003fg, show the clear absorption line of C ii in their early spectra, which are rarely detected for normal SNe Ia (e.g., Marion et al., 2006; Tanaka et al., 2008). Such extremely high luminosities require 1.2 of radioactive Ni if their explosions are spherically symmetric. In order to produce such a large amount of Ni, their progenitor C+O WDs are suggested to have super-Chandrasekhar (super-Ch) mass (i.e., ), because the exploding WDs should contain more than 0.3 of the Si-rich layer and the unburned C+O layer on top of the Ni-rich core (Howell et al., 2006; Hicken et al., 2007; Scalzo et al., 2010; Yuan et al., 2010; Yamanaka et al., 2009; Silverman et al., 2011; Taubenberger et al., 2011). Alternatively, it could also be possible to explain the extremely luminous SNe Ia by asymmetric explosions of Chandrasekhar-mass C+O WDs (Hillebrandt et al., 2007). In this paper, we focus on SN 2009dc and approximate it with a spherically symmetric model, because the spectropolarimetric observations of SN 2009dc suggest that it is a globally spherical explosion (Tanaka et al., 2010).
A super-Ch-mass C+O WD model can be formed if it is supported by rapid rotation. For example, Hachisu (1986) constructed two-dimensional models of rapidly rotating WDs. Uenishi et al. (2003) calculated the structure and evolution of two-dimensional C+O WDs that rotate by getting angular momentum form accreting matter. Yoon & Langer (2005) investigated the stability of rapidly rotating C+O WDs for a wider parameter range.
Explosions and nucleosynthsis of super-Ch-mass C+O WDs were simulated by Steinmetz et al. (1992), Pfannes et al. (2010a), and Pfannes et al. (2010b). Maeda & Iwamoto (2009) studied the bolometric light curves (LCs) of super-Ch-mass WD models. They constructed the homologously expanding models of super-Ch-mass WDs with parameters of WD mass, Ni mass, abundance distribution, and so on. Scalzo et al. (2010) studied the properties of SN 2007if, assuming a shell-surrounded super-Ch-mass WD model as a result of a WD merger. They estimated that the ejecta mass is 2.4 with 1.6 of Ni.
By applying Arnett’s law to the synthesized bolometric LCs, the Ni mass of a SN can be estimated (e.g., Arnett, 1982). Yamanaka et al. (2009) and Silverman et al. (2011) have suggested that SN 2009dc has 1.2 if they neglect the extinction by its host galaxy. They have also reported that the Ni mass could be as large as 1.6–1.7 by taking the extinction into account. Taubenberger et al. (2011) has also analytically estimated that the total mass of SN 2009dc is 2.8 and that the ejected Ni mass is 1.8 . These extreme values challenge current models and scenarios for SNe Ia.
As described above, all the past works rely on the bolometric LCs, which involves some uncertainties (see Section 2.2). In most cases, the analytic method is used to estimate the masses of ejecta and ejected Ni. To derive more accurate properties of the super-Ch candidates for discussing their progenitor scenarios, more sophisticated models are needed. In this paper, we calculate multi-color LCs for homologously expanding models of super-Ch-mass WDs for the first time. Section 2 describes our super-Ch-mass WD models and LC calculations. In Section 3, we compare our results with the photometric and spectroscopic observations of SN 2009dc to estimate the masses of the ejecta and Ni. Implications of our results are discussed in Section 4. We summarize our conclusions in Section 5.
## 2. Models and Calculations
In this section, we describe the procedures for constructing our super-Ch-mass WD models and the code for calculating their LCs, to compare with the observations of SN 2009dc. Since SN 2009dc has a continuum polarization as small as the normal SNe Ia (Tanaka et al., 2010), spherical symmetry is assumed.
### 2.1. Super-Chandrasekhar-Mass White Dwarf Models
To construct the homologously expanding models of super-Ch-mass WDs, we apply the approximations similar to those adopted by Maeda & Iwamoto (2009). The models are described by the following parameters.
• : total WD mass.
• (or ): mass (or mass fraction) of Ni. The mass fraction hereafter means the ratio to ; e.g., .
• : mass fraction of electron-captured elements (ECEs; mostly Fe, Fe, Co, and Ni). Stable Fe, Co, and Ni are included, all of which are simply assumed to have the same mass fraction.
• : mass fraction of intermediate-mass elements (IMEs). Si, S, and Ca are included, whose mass fraction ratio is , similar to that in the Chandrasekhar-mass WD model, W7 (Nomoto et al., 1984; Thielemann et al., 1986).
• : mass fraction of C+O. C and O are contained equally in mass fraction.
Since the equation
fECE+f56Ni+fIME+fCO=1 (1)
holds, we eliminate in the following discussion. In total, we have four independent parameters.
The expansion model of a super-Ch-mass WD is constructed as follows. Firstly, with the above parameters, we calculate the nuclear energy release during the explosion () by
Enuc1051erg=[0.5fECE+0.32f56Ni+1.24(1−fCO)] ×MWDM\sun (2)
(e.g., Maeda & Iwamoto, 2009). Then, the binding energy of the WD () is evaluated by Equations (22) and (32)–(34) described in Yoon & Langer (2005). Here, g cm for all models as in Maeda & Iwamoto (2009), so that increases almost linearly with . For , we extrapolate the formula of (Jeffery et al., 2006). These and give the kinetic energy of the exploding WD as
Ekin=Enuc−Ebin. (3)
How much mass fraction of Ni is synthesized at the deflagration or detonation wave depends mainly on the temperature and thus on the density at the flame front. For W7, e.g., Ni is synthesized at the flame densities of g cm. Then the total synthesized Ni mass depends on the mass contained in this density range, and thus on the presupernova density structure of the WD and the flame speed. The rotating WD is more massive than the non-rotating WD with the same central density (Yoon & Langer, 2005). For the same central density, therefore, the density profile is shallower for more massive stars, and thus the mass contained in the density range for Ni synthesis is larger; i.e., a more massive WD tends to synthesize more Ni. Also, for the same central density, faster flame produces more Ni because of less pre-expansion, and the flame speed depends on the WD mass, rotation law, density structure, and possible transition to detonation. To provide constraints on these physical processes, we calculate the light curve models with various nuclear yields and for the same central density models.
Next, the structure of the explosion model of a super-Ch-mass WD is obtained by scaling W7, the canonical Chandrasekhar-mass WD one, in a self-similar way. We scale the density () and velocity () of each radial grid in the model as
ρ∝M5/2WDE−3/2kin (4)
and
v∝M−1/2WDE1/2kin. (5)
We then consider the distribution of four element groups (ECEs, Ni, IMEs, and C+O). We assume that Ni in a super-Ch-mass WD model is mixed. The inner boundary of the mixing region is set to be km s for all the models, because the observed line velocities of Si ii are 5000 km s (Yamanaka et al., 2009). And we set the outer boundary of the mixing region based on the mass coordinate; . Here the reference mass coordinate ( ) is the outer boundary of the Ni distribution in the W7 model. This outer boundary corresponds to that of the Ni-produced zone in the W7 model. By these definitions, the mixing region is uniquely set when we choose four model parameters. Note that, for our models, the velocity at the outer boundary of the mixing region differs among models even with the same , due to the scaling by Equation (5). This mixing is important to account for the observed velocities of the Si ii line (see Section 3.2).
To demonstrate the scaling and mixing, we plot the structure and abundance distribution of the two super-Ch-mass WD models in Figure 1. The model plotted on the left panels had no IMEs at km s before being mixed; the mixing has extended Ni outwards and IMEs inwards. In some models, C+O are also mixed inwards as in the model right in Figure 1.
We set the parameter range as follows to compare the models with the observations of SN 2009dc.
• , 2.0, , 2.8.
• , 1.4, , 1.8, 1.9, 2.0.
• , 0.2, 0.3.
• , 0.2, 0.3, 0.4.
Here, is obtained by using Equation (1). Any models which have are not constructed (e.g., models with , , and ). We also excluded a model where the inner boundary of the IMEs layer without mixing is located outer than the mixing region (e.g., a model with , , and ), because no IMEs extend inwards by mixing. The parameters and of our models are listed in Columns 2–5 of Table 1.
### 2.2. Light Curve Calculations
Multi-color LCs for the constructed models are calculated with STELLA code (Blinnikov et al., 1998, 2000, 2006), which solves the one-dimensional equations of radiation hydrodynamics. STELLA was first developed to calculate LCs of Type II-L supernovae (Blinnikov & Bartunov, 1993). Its applications to SNe Ia are described in Blinnikov & Sorokina (2000), Blinnikov et al. (2006), and Woosley et al. (2007). In the present study, we use homologously expanding ejecta as input (see Section 2). Then the radiation hydrodynamics calculation is performed for each model. Maeda & Iwamoto (2009) used the one-dimensional gray radiation transfer code (Iwamoto, 1997; Iwamoto et al., 2000), where they assumed simplified opacity for line scatterings. STELLA, on the other hand, considers 155000 spectral lines in LTE assumption to calculate the opacity with expansion effect more realistically, as well as free-free/bound-free transitions and Thomson scattering.
We note here that the “bolometric” luminosity reported from the observations is the luminosity (). Yamanaka et al. (2009) derived by assuming that (actually observed) integrated luminosity () is 60% of . This is commonly applied for normal SNe Ia (Wang et al., 2009a). Since it is still unknown whether this assumption is applicable to super-Ch candidates, we directly compare theoretical and observed rather than . This is advantage of our multi-color calculations. In the calculations, the bolometric, , and LCs cover 1–50000 Å, 1650–23000 Å, and 3850–8900 Å, respectively.
### 2.3. Extinction
To compare the calculated and observed LCs, the observational data must be corrected for the extinction. In order to correct the extinction, three values are needed; the excesses for the Milky Way () and the host galaxy of SN 2009dc (), and the ratio of the -band extinction to the B V excess () of the host galaxy ( is set to be 3.1 for the Milky Way). Of these values, and of the host galaxy are somewhat difficult to estimate.
The observed Na i absorption line in the host galaxy suggests that the reddening caused by it is not negligible. To estimate , one may use the observed color. However, the observed B V of SN 2009dc is significantly different from normal SNe Ia, which may suggest that the Lira-Phillips relation (Lira, 1996) should not be applied. The other method to derive is using the equivalent width of the Na i D absorption line (EW, e.g. Turatto et al., 2003). But it is also noted that the observed EW has a (relatively) large error (Silverman et al., 2011; Taubenberger et al., 2011). Also for , a non-standard, smaller value (3.1) may be preferred for normal SNe Ia (e.g. Nobili & Goodbar, 2008; Wang et al., 2009b; Folatelli et al., 2010; Yasuda & Fukugita, 2010). If the host galaxy of SN 2009dc also has , its extinction is overestimated.
To cover most of possible ranges of extinction, we consider two extreme cases, where the extinction by the host galaxy is negligible ( mag) and significant ( mag), respectively. We set mag, and for the host galaxy (same as for the Milky way). An extinction law by Cardelli et al. (1989, Table 3) is applied.
## 3. Results
### 3.1. Bvri Light Curves
The left panel in Figure 2 shows the calculated LCs for the super-Ch-mass WD models with different . The other parameters are set to be the same ( , , and ). A clear relation is seen between the LCs and from this panel; a more massive model shows a broader LC.
Such a mass dependence is consistent with the relation between the timescale of the bolometric LC () and ,
tbol∝¯κ1/2M3/4WDE−1/2kin (6)
(Arnett, 1982), where is the opacity averaged in the ejecta (although does differ among models and with time). Note that anticorrelates with for the models plotted in the left panel of Figure 2 because and are fixed (c.f. Table 1).
We consider a timescale to see quantitatively if the LCs depends on and , analogous to Equation (6). For this purpose, we take the declining timescale (), which is defined as the time for the LC to halve its luminosity after the peak. In the left panels of Figure 3, shown are the (large panel), (small, top), and (small, right) plots for the models listed in Table 1. The LCs of the massive and less energetic models tend to be wider (i.e. larger ), which is expected from the left panel in Figure 2. For the dependence of on and , we plot against in the right panel of Figure 3. An almost linear relation is seen between and . We thus confirm a relation similar to Equation (6) for the LCs.
The calculated and observed LC are shown on the right panel in Figure 2, by setting the dates of maximum in the -band of the models and observations at the same day as day. We plot the observational data provided by Yamanaka et al. (2009), neglecting the extinction by the host galaxy (open squares). The open triangle corresponds to the early -band detection by Silverman et al. (2011), where we simply assume that the -band luminosity is equivalent to 20% of , i.e., of , assuming (cf. Wang et al., 2009a, Figure 24). The LCs of the super-Ch-mass WD models on the right panel are as luminous as the observations around the maximum, while some have relatively broader LCs or shorter rising time than the observations. Especially, the two less massive models (–2.0 ) are not preferred because they are too faint at days.
In order to find the well-fitted models, we calculate the weighted root-mean-square residual (WRMSR) of the LC,
WRMSR= ⎷1NN∑i=1⎛⎜⎝L(calc)BVRI,i−L(obs)BVRI,iδL(obs)BVRI,i⎞⎟⎠2 (7)
for each model. We use the observational data for days taken from Yamanaka et al. (2009), where the total number of the observations, , is 23 for this time range. The early detection by Silverman et al. (2011) is excluded in calculating the WRMSR. Here, and respectively denote of the observation and calculation obtained at the -th epoch. is the observational error of , which is set to 20% of . Maeda & Iwamoto (2009) used the decline rate of the bolometric LC after maximum for comparison between their models and observations. We use the above WRMSR instead of the decline rate, so that brightness can also be taken into account. The WRMSR is calculated with the observational error, and shows which model fits relatively to the observed LC.
We list the WRMSR of the models for the two extinction cases in Columns 7 and 8 of Table 1. Good agreement is found between the calculated and observed LCs for whole range of in this study, if the extinction by the host galaxy is not considered. In the case where the extinction is corrected, most models have larger WRMSR (due to smaller ), while some models with large and are better fitted.
### 3.2. Photospheric Velocity
Next, we compare the photospheric velocity () of the models and the observed line velocity of Si ii. In the last column of Table 1, listed are the ranges of our models at days. This period covers the whole phases of the spectroscopic observations by Yamanaka et al. (2009). We estimate the position of the photosphere (hence, ) in the model from the optical depth at the -band, where the rest-frame wavelength of the observed Si ii line (6355 Å) is located.
The velocity of the observed Si ii line is reported as 9000 km s at the period (Yamanaka et al., 2009). Since the Si ii absorption line is formed by the Si above the photosphere, the calculated should be smaller than the observed Si ii line velocity (for further details, see Tanaka et al., 2011, Figure 1). For the models with and 2.0 , however, the calculated are 10000 km s, much larger than the observed line velocity of Si ii. Thus, these less massive models are far from consistent with SN 2009dc. On the other hand, many models with have km s during days, which are somewhat compatible with observations. These models with small commonly have such a large C+O mass fraction as –0.4. From Equation (2), and thus are affected mainly by rather than . A model with larger has smaller , thus smaller and , being preferred for SN 2009dc.
### 3.3. Plausible Models for SN 2009dc
In order to find the most plausible model for SN 2009dc, we first select models based on LC and discussed above. We use criteria of WRMSR and km s during the days. By these criteria, models with a label AO in Column 1 of Table 1 are selected. Among them, models AM are selected for the case where the host-galaxy extinction is neglected; only models N and O for the significant extinction. In Figure 4, we plot WRMSR and maximum during the period, where the dotted lines indicates the criteria.
We further analyze multi-color LCs of these models. Figures 59 show the (left), (right top) monochromatic LCs (right bottom) of these models. In these figures, the , -, -, -, and -band LCs by Yamanaka et al. (2009) and the early detection and -band LC by Silverman et al. (2011) are plotted as squares and triangles, respectively. Filled and open symbols show the observed LCs with and without the extinction correction.
With Figures 59, we make more detailed comparisons of models AO with the observational data of SN 2009dc. The comparisons are summarized as follows:
• The early detection in Silverman et al. (2011) enables us to constrain the rising time of the models. The -band LCs of models E, H, and M are too bright at days regardless of whether the host-galaxy extinction is corrected or not. These models can be excluded because their LCs evolve too slowly.
• The remaining models for the case of the neglected host-galaxy extinction (AD, F, G, and IL) have as small as 1.2 and 1.4 , which is consistent with the analytical estimates. While model J has the smallest WRMSR, its is relatively larger than the observations. Models D, G, and L also have larger around day. Among the other models (AC, F, I, and K), the models with (AC) are preferred, because their LCs reproduce the observations well around the peak. Especially, model B has the smallest of the three models, so we suggest that model B is the most plausible model for SN 2009dc without the host-galaxy extinction.
• If the extinction by the host galaxy is significant, we have only two candidate models with (N and O). They both have similar properties; slightly larger at days, but a bit smaller around day. We regard model N as the most plausible model for the extinction-corrected case because the rising time is shorter than model O.
By these results, we suggest that the mass of progenitor WD of SN 2009dc is 2.2–2.4 if the extinction by its host galaxy is negligible, and 2.8 with the extinction if the extinction is significant. The Ni mass needed for the SN is 1.2–1.4 for the former case, and 1.8–1.9 for the latter, respectively. For the latter case with extinction, the estimated masses are consistent with those suggested by Taubenberger et al. (2011), though they assume that the mean optical opacity of SN 2009dc is similar to (normal) SN 2003du.
For SN 2007if, one of the super-Ch candidates, Scalzo et al. (2010) estimate the total mass of its progenitor to be 2.4 , as massive as we estimate for SN 2009dc. They consider a shell-structured model to explain the low Si ii line velocity and its plateau-like evolution, where the massive envelope decelerates the outer layers of the ejecta. Our calculations also reproduce the lower Si ii line velocity and similar evolution of SN 2009dc (the right-top panels of Figures 59), and suggest that the low line velocity and flat evolution of Si ii can be explained by scaled super-Ch-mass WD models, as well as the shell-shrouding models.
## 4. Discussion
### 4.1. Light Curves of Super-Chandrasekhar-Mass White Dwarf Models
#### 4.1.1 Multi-Color Light Curves
We have calculated the multi-color LCs of the super-Ch-mass WD model for the first time (right-bottom panels in Figures 59). Even the model being in good agreement with and shows discrepancy for each band to some extent, especially in the band. This deviation from observed SNe Ia in the band is also seen for a Chandrasekhar-mass WD model calculated by the code STELLA (Woosley et al., 2007, Figure 9). It could be improved by taking more spectral lines into account for the opacity calculation.
The comparison with the velocity suggests that the mixing occurred in the ejecta. It is interesting to note that LCs of SN 2009dc in the band do not clearly show double-peak features. For Chandrasekhar-mass WD models, Kasen (2006) calculated the multi-color LCs, to conclude that mixing in the ejecta could produce the single-peak LCs in the band. In fact, our models are partially mixed and their -band LCs do not show two peaks (Figures 59). It could be also the case for super-Ch-mass WD models that mixing affects their -band LCs, although some uncertainties mentioned above should be taken into account.
#### 4.1.2 Bolometric, uvoir, and Bvri Light Curves
In Figure 10, the bolometric, , and LCs are plotted for models W7, B, and N. The LCs peaks earlier than the LCs, by 2 days for W7 model, and by 10 days for model B and N, respectively. As for the peak luminosity, the LC of W7 is brighter than the LCs by 0.2 dex, while those of the two super-Ch-mass WD models, by 0.3 dex. These shifts are understood by considering the ultraviolet (UV) radiation in the early phase (Blinnikov & Sorokina, 2000).
Most of LCs for the super-Ch-mass WD models in this paper seems to be fainter for day and slightly brighter after that, than the observations (Figures 510). This discrepancy could be solved by changing the Ni distribution in the model, which powers its radiation. The more Ni outside could shorten the rising time, or make more luminous before the peak, while the less Ni inside could make fainter after that. Further detailed modeling is needed since we simply assume the Ni distribution analogous to W7.
In Figure 10, we add the observation data for days plotted in Figure 7 of Taubenberger et al. (2011) as filled pentagons, which are also corrected for the host-galaxy extinction by using their values. The calculated bolometric LC fits to the observed LC tail quite well. The observed tail lie just on model N, which means that the estimate on for the model is consistent.
### 4.2. Instabilities of Rotating White Dwarfs
We calculate by just extrapolating the formula, valid only for Yoon & Langer (2005). Using their Equations (22) and (29)–(31), we can calculate the ratio of the rotational energy () to (the magnitude of) gravitational one of () a super-Ch-mass WD with our parameter . This ratio indicates the stability of the WD. If is small enough, the WD is stable against rotation. If reaches 0.14, the WD suffers the non-axisymmetric instability (e.g. Ostriker & Bodenheimer, 1973). The above equations show that a WD with has for our . A super-Ch-mass WD with might not form. However, as a function of differs with the rotation law (e.g., Hachisu, 1986), so that it is possible that even such a massive WD as has and thus form. We thus consider the models with .
Our results in this paper suggest that the progenitor WD mass of SN 2009dc exceeds 2.2 even for the case where the host-galaxy extinction is negligible. Such a large might suggest that the explosion of this super-Ch-mass WD is triggered when its mass reaches the critical mass for the above instability of the rotating WDs (Hachisu et al., 2012).
### 4.3. Possible Progenitors and Scenarios
The progenitor WD mass for SN 2009dc in our estimate largely exceeds , thus putting severe constraints on the presupernova evolution of the binary system. This also should have important implications on the progenitor scenarios of ordinary SNe Ia, both the single degenerate (SD) and double degenerate (DD) scenarios.
#### 4.3.1 Single Degenerate Scenario
The initial masses of the WD () and its companion star () should be sufficiently large at the beginning of accretion in order to increase to 2.4 . Chen & Li (2009) argued that even for the accretion from the companion of does not obtain . However, they does not take into account the effect of mass-stripping from the companion star due to the strong WD wind (Hachisu et al., 2007). Because the mass-stripping effectively reduces the mass transfer rate from the companion to the WD, the companion star can be as massive as –7 and can reach 2.4 (Hachisu et al., 2012). Still, to realize such a massive WD, is preferable (Chen & Li, 2009; Hachisu et al., 2012).
The formation of the C+O WD with is realized in the special binaries. In stars of main-sequence mass of 8 , the C+O core mass is 1.07 to avoid off-center C-ignition before the AGB phase (e.g., Umeda et al., 1999). After the dredge-up of the He layer, the C+O core increases its mass during the AGB phase, if the binary separation is wide enough to accommodate the AGB star. In such a binary system, the C+O WD with can be formed, if the C+O core of the AGB star has already grown massive when the AGB envelope is lost in a wind or by Roche-lobe overflow. Thus is larger if the mass loss rate from the AGB star is smaller. Therefore, the C+O WDs with larger is more likely to form in the lower metallicity system and in the initially wider binary (Hachisu et al., 2007). Since the binary must also be close enough for the mass-transfer to occur, the suitable binary system could be rare, which is consistent with the low occurrence frequency of the super-Ch-mass explosion.
These requirements of large enough and in the SD scenario predicts that SNe Ia from super-Ch-mass WDs are associated with the star-forming region and low metallicity environment. It is interesting to note that the hosts of the observed super-Ch candidates are faint and star-forming galaxies except for SN 2009dc (e.g. Taubenberger et al., 2011, Table 7). For SN 2009dc, the host galaxy UGC 10064 is a passive (S0) galaxy. However, at 40 kpc away from UGC 10064, there is a blue irregular galaxy UGC 10063, which could also have a star formation in the recent past by the interaction (Silverman et al., 2011).
#### 4.3.2 Double Degenerate Scenario
For the DD scenario, to form a WD of 2.4 by merging of two C+O WDs, the primary C+O WD needs to be initially as massive as because of the following reason. To form a massive C+O core in the primary AGB star, the initial binary system needs to be wide enough. The Roche lobe overflow of the primary AGB star is so rapid that a formation of a common envelope is unavoidable. After the loss of mass and angular momentum from the common envelope, a primary C+O WD and the secondary star are left in a binary with a small separation. If the separation is too small for the secondary star to become an AGB star, the mass of the secondary C+O WD is . In order to form a WD of 2.4 , the primary C+O WD should be more massive than 1.33 , which would be very rare. In the above scenario, formation of the double C+O WDs whose initial masses are both 1.2 may not be possible because of the shrink of the binary system after the first common envelope phase.
## 5. Conclusions
To constrain the properties of SN 2009dc, we have calculated multi-band LCs for the exploding super-Ch-mass WD models with a range of model parameters. We find that the mass of the WD and other model parameters are constrained as follows.
• The observed LCs of SN 2009dc are well-explained by the super-Ch-mass WD models with –2.8 and –1.8 , if the extinction by the host galaxy is negligible.
• The observed line velocity of Si ii is consistent with of several models with –2.8 , but significantly lower than of the less massive models.
• Among our models, the most plausible model is model B with (1.2 of Ni, 0.24 of ECEs, 0.24 of IMEs, and 0.72 of C+O) for the case without the host-galaxy extinction.
• If the extinction is considered, the mass of the super-Ch-mass WD needs to be as massive as (i.e. model N with 1.8 of Ni, 0.28 of ECEs, 0.16 of IMEs, and 0.56 of C+O). We find that the fit to the observation is less successful for model N than model B.
• Such a large might suggest that the explosion of the super-Ch-WD might be related to the onset of the instability of the differentially rotating WD.
Our results in this paper are based on the simplified models of the super-Ch-mass WDs. There are still several uncertainties in the models and LCs; such as the parameterization of the models, the opacity calculated by the code, aspherical effects, and effects of possible circumstellar interaction, as well as the instability of the massive WDs. However, and of the plausible models for SN 2009dc are quite consistent with the observations, suggesting that our present approach works well for this super-Ch candidate.
We are grateful to Masayuki Yamanaka for providing us the detailed observation data of SN 2009dc, to Keiichi Maeda and Nozomu Tominaga for the constructive discussion on the construction and LC calculations of super-Ch-mass WDs models. Y.K. acknowledges the Japan Society for the Promotion of Science (JSPS) for support through JSPS Research Fellowships for Young Scientists, and his work is supported by Grant-in-Aid for JSPS Fellows #227641. The work of S.I.B. and E.I.S. in Japan is supported by the Ministry of Education, Culture, Sports, Science and Technology; and in Russia by grants RFBR 10-02-00249-a and 10-02-01398-a, the Grant of the Government of the Russian Federation (No. 11.G34.31.0047), Sci. Schools-3458.2010.2 and -3899.2010.2, and a grant IZ73Z0-128180/1 of the Swiss National Science Foundation (SCOPES). This research has been supported in part by the Grant-in-Aid for Scientific Research of MEXT (22012003, 22840009, and 23105705) and JSPS (23540262) and by World Premier International Research Center Initiative, MEXT, Japan.
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https://projecteuclid.org/euclid.rmi/1161871349
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## Revista Matemática Iberoamericana
### Riesz transforms for symmetric diffusion operators on complete Riemannian manifolds
Xiang Dong Li
#### Abstract
Let $(M, g)$ be a complete Riemannian manifold, $L=\Delta -\nabla \phi \cdot \nabla$ be a Markovian symmetric diffusion operator with an invariant measure $d\mu(x)=e^{-\phi(x)}d\nu(x)$, where $\phi\in C^2(M)$, $\nu$ is the Riemannian volume measure on $(M, g)$. A fundamental question in harmonic analysis and potential theory asks whether or not the Riesz transform $R_a(L)=\nabla(a-L)^{-1/2}$ is bounded in $L^p(\mu)$ for all $1<p<\infty$ and for certain $a\geq 0$. An affirmative answer to this problem has many important applications in elliptic or parabolic PDEs, potential theory, probability theory, the $L^p$-Hodge decomposition theory and in the study of Navier-Stokes equations and boundary value problems. Using some new interplays between harmonic analysis, differential geometry and probability theory, we prove that the Riesz transform $R_a(L)=\nabla(a-L)^{-1/2}$ is bounded in $L^p(\mu)$ for all $a>0$ and $p\geq 2$ provided that $L$ generates a ultracontractive Markovian semigroup $P_t=e^{tL}$ in the sense that $P_t 1=1$ for all $t\geq 0$, $\|P_t\|_{1, \infty} < Ct^{-n/2}$ for all $t\in (0, 1]$ for some constants $C>0$ and $n > 1$, and satisfies $$(K+c)^{-}\in L^{{n\over 2}+\epsilon}(M, \mu)$$ for some constants $c\geq 0$ and $\epsilon>0$, where $K(x)$ denotes the lowest eigenvalue of the Bakry-Emery Ricci curvature $Ric(L)=Ric+\nabla^2\phi$ on $T_x M$, i.e., $$K(x)=\inf\limits\{Ric(L)(v, v): v\in T_x M, \|v\|=1\}, \quad\forall\ x\in M.$$ Examples of diffusion operators on complete non-compact Riemannian manifolds with unbounded negative Ricci curvature or Bakry-Emery Ricci curvature are given for which the Riesz transform $R_a(L)$ is bounded in $L^p(\mu)$ for all $p\geq 2$ and for all $a>0$ (or even for all $a\geq 0$).
#### Article information
Source
Rev. Mat. Iberoamericana, Volume 22, Number 2 (2006), 591-648.
Dates
First available in Project Euclid: 26 October 2006
https://projecteuclid.org/euclid.rmi/1161871349
Mathematical Reviews number (MathSciNet)
MR2294791
Zentralblatt MATH identifier
1119.53022
#### Citation
Li, Xiang Dong. Riesz transforms for symmetric diffusion operators on complete Riemannian manifolds. Rev. Mat. Iberoamericana 22 (2006), no. 2, 591--648. https://projecteuclid.org/euclid.rmi/1161871349
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https://arxiv.org/abs/1008.1248
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astro-ph.SR
(what is this?)
(what is this?)
# Title: Large Amplitude Photometric Variability of the Candidate Protoplanet TMR-1C
Abstract: In their HST/NICMOS observations, Terebey et al. 1998 detected a candidate protoplanet, TMR-1C, that lies at a separation of about 10" (~1000 AU) from the Class I protobinary TMR-1 (IRAS 04361+2547). A narrow filament-like structure was observed extending south-east from the central proto-binary system towards TMR-1C, suggesting a morphology in which the candidate protoplanet may have been ejected from the TMR-1 system. Follow-up low-resolution spectroscopy could not confirm if this object is a protoplanet or a low-luminosity background star. We present two epochs of near-infrared photometric observations obtained at the CFHT of TMR-1C. The time span of ~7 years between the two sets of observations provides with an opportunity to, (a) check for any photometric variability similar to that observed among young stellar objects, which would indicate the youth of this source, and, (b) determine the proper motion. TMR-1C displays large photometric variability between 1 and 2 mag in both the H- and Ks-bands. From our 2002 observations, we find a (H-Ks) color of 0.3 mag, which is much bluer than the value of 1.3 mag reported by T98 from HST observations. Also, we observe brightening in both the H- and Ks-bands when the colors are bluer, i.e. the object gets redder as it becomes fainter. We have explored the possible origins for the observed variability, and find extinction due to the presence of circumstellar material to be the most likely scenario. The observed large-amplitude photometric variations, and the possible presence of a circumstellar disk, are strong arguments against this object being an old background star.
Comments: Accepted in A&A Subjects: Solar and Stellar Astrophysics (astro-ph.SR) DOI: 10.1051/0004-6361/201014083 Cite as: arXiv:1008.1248 [astro-ph.SR] (or arXiv:1008.1248v1 [astro-ph.SR] for this version)
## Submission history
From: Basmah Riaz [view email]
[v1] Fri, 6 Aug 2010 18:13:23 GMT (704kb)
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https://space.stackexchange.com/questions/34454/has-any-human-ever-had-the-choice-to-leave-earth-permanently/34459
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# Has any human ever had the choice to leave Earth permanently?
Far beneath the ship / The world is mourning
They don't realize / He's alive
No one understands
But Major Tom sees / "Now the light commands
This is my home / I'm coming home."
Peter Schiling, Major Tom
I found myself waxing poetic after reading this question about the indicator light to tell when Apollo 8 entered the moon's sphere of influence.
When that light came on there was silence – it was a kind of dawning – we were witnessing the first time human beings were falling away from the Earth.
What goes up must come down. It's a law. This is simply how it works. Or worked. In the last century we developed enough technology to go up... and stay up. Someone who enters the moon's sphere of influence can simply choose not to initiate any burn, and wait for their final destination on the moon, never to return to earth again.
But the moon is destined to come home as well:
The Moon will be torn to pieces and every crater, mountain, valley, footprint and flag will be scattered to form a spectacular 23,000-mile-diameter (37,000-kilometer) Saturn-like ring of debris above Earth's equator. The new rings will be short-lived. Theory dictates they'll eventually rain down onto Earth's surface.
So even those who have had the opportunity to spend the rest of their days on the moon (should they have chosen as such) were destined to return, though on a much longer timescale than one might otherwise think.
Of the 533 humans who have been in orbit, have any of them been sent into space with enough propellant to actually escape Earth's grasp, should they have chosen to use the fuel in that manner? Has any human ever had the choice to never return to Earth? (or at least choice not to return with the blessings of ground control, in case there were any missions where the astronauts had the delta-V but not the authority required to use it)
• Just a note: the Moon getting torn to pieces is not nearly as sure as it was believed not long ago. Moon is constantly accelerated by Earth's tidal forces into increasingly higher orbit, and opinions are on the fence whether it will a) enter mutual tidal lock with Earth, then gradually spin down and get torn to pieces, b) escape Earth's gravity, c) get swallowed by expanding Sun, along with Earth before either of two other options happen. – SF. Feb 26 '19 at 8:58
• Has any human ever been aboard a spaceship capable of leaving Earth's sphere of influence? ('leaving Earth permanently' has been a choice of everyone who's ever set foot on the moon) – Mazura Feb 27 '19 at 0:58
• @Mazura No. You didn't read the question. The point is that the moon (and hence everything on it) is due to fall back to earth eventually. (Although SF questions that premise). – Martin Bonner supports Monica Feb 27 '19 at 15:35
• @MartinBonner True. There's more cut and dry phrasing of this to find humans who could have left the sphere of influence of earth and the moon. I chose this phrasing for three reasons. 1) It's more poetic. 2) It's closer to what I'm actually interested in, and 3) in phrasing this way I also opened the door up for frame challenges like SF's comment above. – Cort Ammon - Reinstate Monica Feb 27 '19 at 15:44
• @SF - where are you getting this? We're loosing our moon at like 2.5 centimeters a year or something. How's that ever going to stop if it's outside the Roche radius? – Mazura Feb 28 '19 at 0:23
Of the 533 humans who have been in orbit, have any of them been sent into space with enough propellant to actually escape Earth's grasp, should they have chosen to use the fuel in that manner? Has any human ever had the choice to never return to Earth?
Apart from the Apollo missions, no crewed spacecraft has had anything like enough propellant to leave Earth orbit.
Apollo is a very different story. After translunar injection, the Apollo CSM/LM stack could produce an additional 3600 m/s of delta-V by expending first the lunar module stages and then burning all the service module fuel. This is enough to reach Venus, Mars, the asteroid belt, or even Jupiter. However, the ship would only have crew life support for a couple of weeks at most -- not enough to reach any interesting destination alive.
• I think you'd get more delta-V by first firing the CSM, then descent, then ascent module. (might get even more if one could use the descent module without the ascent module but I think that would be impossible. Also, firing all these in LEO would result in massive Oberth benefits. Still, obviously there was not nearly enough life support capacity to get anywhere far. – SF. Feb 26 '19 at 9:19
• @Mehdi Hang on, they're in the notoriously unforgiving environment of space, sat on top of tonnes of explosives, supplied with breathable air by a sometimes-temperamental filter, kept at a survivable temperature by a sometimes-temperamental AC system - and you're looking to give them yet another way to die quickly? What's wrong with any one of the myriad of things which they need to actively stop from killing them? – Graham Feb 26 '19 at 17:24
• @Mehdi Jim Lovell is on record as saying that if the crew wanted to commit suicide, they'd simply vent the cabin to space. They'd lose consciousness with little discomfort in seconds and die shortly thereafter. See this QA for more on the topic. – Russell Borogove Feb 26 '19 at 18:19
• @Mehdi: No. The astronauts said later the way to commit suicide was to open the cabin re-pressurization valve (it's supposed to be used while floating in the ocean). – Joshua Feb 26 '19 at 19:45
• It's worth noticing that the delta v to reach the moon is almost the same as the delta v required to escape earth, and to actually get in an orbit around the moon you'd need more than for escaping earth. – paul23 Feb 26 '19 at 21:54
Soyuz 11
The crew did not return to Earth in their lifetimes. This interpretation is obviously not what you are talking about though. Instead what is of interest is human's remains that do not return to Earth ever. In this case there is also a definitive answer.
Clyde Tombaugh
Tombaugh died on January 17, 1997, when he was in Las Cruces, New Mexico, at the age of 90. He was cremated. A small portion of his ashes was placed aboard the New Horizons spacecraft.
You may consider this cheating since it was only a small portion of his remains, but more than just a hypothetical, it actually happened, and not only did this portion of his remains escape the grasp of Earth, but also the grasp of the sun.
• Neither of those are the kind of thing I'm looking at, but I applaud the clever reinterpretations, especially Clyde Tombaugh! I had not even considered the case where the decision to leave the Earth's grasp was made on the ground, rather than mid-flight (and posthumously, no less!). That's definitely in the spirit of what I was after, even if there's some definite technicalities involved! – Cort Ammon - Reinstate Monica Feb 26 '19 at 3:09
• @CortAmmon see also Gene Roddenberry – mcalex Feb 26 '19 at 3:31
• For Soyuz 11, they died at 168 kilometres altitude, so they did not escape Earth's grasp and their bodies fell back to Earth. – Cœur Feb 27 '19 at 3:49
• @Cœur hence why I said they did not return to Earth "in their lifetimes." I mainly brought it up to highlight the point that the question really pertains to human remains and not living humans, before giving the answer as it pertains to human remains. – Lex Feb 27 '19 at 4:53
• Dead people don't have choices, if you're going to start the pedantry. – jpmc26 Feb 27 '19 at 16:31
No and yes.
Rockets are costly things and no human ever left Low Earth Orbit, except the Apollo astronauts. Others had not enough fuel to do that.
The Apollo astronauts had theoretically the option to contradict their mission requirements and choose death
• on the Moon
• on Moon orbit
• or somewhere between the Moon and Earth
by commiting a suicidal sabotage. They didn't do it on obvious reasons.
One of the worst known violation of their rules was as John Young astronaut has taken a sandwitch with him into the space.
The escape speed from the Earth from Lunar orbit is already very small, it is possible, that the few fuel of the Apollo - reserved for orbital correction - could have been enough to visit the interplanetary space - without any way to ever return.
• "without any way to ever return" - you'd still be on an Earth-intersecting orbit. You could just sit and wait. Might get home, might smash into the Moon, might get swept by a lone asteroid. It will take a lone time and the probability is low, but you might still get back to Earth by accident eventually. – John Dvorak Feb 25 '19 at 17:46
• @JohnDvorak Yes, it would be intersecting and probably not very far from the orbit of the Earth, however a next hit of the Earth - after a year - would be still very improbable. The probable result would be a near-Earth travel after $\approx$ a year, and then a Tesla Roadster-like chaotical orbit. It is nearly sure, that the ship would not enough fuel to hit Earth, even if it would be still working (probably it wouldn't, the whole Apollo travel was planned for a week, not for a year). – peterh - Reinstate Monica Feb 25 '19 at 17:50
• "not in orbit" Around what? – Organic Marble Feb 25 '19 at 19:01
• @NuclearWang Apollo may have had enough fuel to leave Earth's orbit, but you need way more fuel to leave the solar system. I've checked. – John Dvorak Feb 25 '19 at 19:23
• @JohnDvorak Escape velocity from the Solar System is around 42km/s from the orbit of the Earth. The Earth is already moving with 29.8 km/s, so around 12.2km/s delta V would be enough to an escape from the Solar System. Now the problem is that typical satellites, probes have around some hundreds m/s delta V reserve after they've left the gravitational well of the Earth. – peterh - Reinstate Monica Feb 25 '19 at 19:50
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https://dukestatsci.github.io/thesis-sp18-brown-hothand/1-data.html
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# Chapter 1 Data
## 1.1 Description of Dataset
The data for this analysis comes from SportVU, a player-tracking system from STATS, LLC. that provides precise coordinates for all ten players and the ball at a rate of 25 times per second. The Duke University Men’s Basketball team permitted us to use their SportVU data from the 2014 to 2017 basketball seasons for this project. Since the ability to record this data depends on specialized tracking cameras, Duke does not have this data for every game they play—only home games, and a few road games in arenas that had the technology installed. Therefore, there is a substantial amount of missing data between games. More specifically, between the 2014 and 2017 seasons, the Duke Men’s Basketball team played 147 games; this dataset contains 94 games, with 82 at Duke and 12 at other arenas.
For our analysis, we use the following files for each game:
• Final Sequence Play-by-Play Optical:
This dataset comes in an a semi-structured Extensible Markup Language (XML) file, where there is a unique element for each “event” (an event is a basketball action such as a dribble, pass, shot, foul, etc.). Each event element has attributes describing the type of event, the time of the event, and the player who completed the action. We use these files to uncover when a shot is attempted in a game, who attempted the shot, and the result of the shot attempt.
• Final Sequence Optical:
These XML files contain the locations of all ten players and the ball during precise time intervals within the game (25 times per second). Each time unit has a unique element, and these elements have attributes describing the locations. We merge this with the Final Sequence Play-by-Play Optical data on the time attribute to obtain the shooter’s location at the moment of a shot attempt.
## 1.2 Data Cleaning
Steps taken to clean the merged shooter IDs with shot locations include translating the locations to a half-court setting (the teams switch sides of the court halfway through every game, which means that we have to flip the coordinates across the middle of the court for about half of the shots in every game), converting the x-y coordinates to polar coordinates (in the units of feet and radians), and adding an indicator for home games. We only use the shots that Duke players attempt, because there is an inadequate amount of data for players on other teams—no opposing players appear in more than 5 games. The final dataset contains 5,467 observations from 31 shooters over 94 games. A summary of the cleaned dataset is in Table 1.1:
Table 1.1: Summary of Dataset
Name Type Values Extra Details
season categorical {2014, …, 2017}
gameid categorical NA 94 unique values
time continuous NA 13-digit timestamp in milliseconds
globalplayerid categorical NA 31 unique values
r continuous [0, $$\infty$$) Distance of shot from basket (feet)
theta continuous [-$$\pi$$, $$\pi$$] Angle of shot (radians)
home categorical {0,1} 1 if shot occured in a home game
result categorical {0,1} 1 if shot was made (response)
A small subset of the cleaned data is displayed below in Table 1.2:
Table 1.2: Sample of Dataset
season gameid time globalplayerid r theta home result
2014 201401070173 1389141733839 603106 4.2076 1.0746 1 1
2014 201401070173 1389141844712 601140 16.6537 1.2973 1 0
2014 201401070173 1389143172185 696289 18.7901 -0.0581 1 1
2014 201401070173 1389143196303 601140 23.4629 0.9539 1 1
2014 201401070173 1389143220261 756880 6.5365 0.0696 1 0
Figure 1.1 shows the locations of all the shots in the dataset, translating the locations to one half of the court, and excluding heaves from beyond half court. The variable $$\theta$$ has a range of $$2\pi$$ radians, but this plot shows that most of the attempts occur within the interval (-$$\frac{\pi}{2}$$, $$\frac{\pi}{2}$$). This figure also shows the bimodal distribution of shot distance over all players.
## 1.3 Exploratory Data Analysis
The exploratory data analysis plots in Figure 1.2 examine how consistent the probability of a made shot is, using a loess smooth curve on the binary outcomes. We present these smoothed plots for four high-usage basketball players at Duke University between the 2014 and 2017 seasons. Each plot represents a single player’s ordered shooting outcomes for a single season. These plots do not account for the amount of time in between shots, but simply shot order and outcome.
We can see that the players vary in the consistency of their made shots, since they all contain spikes and trends. For example, Player 3 initially has a very high success rate, which quickly falls to the middle after about 30 shot attempts, and the Player 2 has a noticeable upward trend in shot success beginning around shot number 150.
We investigate the shooting outcomes using Bayesian models, and present the results in the next chapter.
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https://projecteuclid.org/euclid.aos/1176345153
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## The Annals of Statistics
### On Improving Convergence Rates for Nonnegative Kernel Density Estimators
#### Abstract
To improve the rate of decrease of integrated mean square error for nonparametric kernel density estimators beyond $0(n^{-\frac{4}{5}}),$ we must relax the constraint that the density estimate be a bonafide density function, that is, be nonnegative and integrate to one. All current methods for kernel (and orthogonal series) estimators relax the nonnegativity constraint. In this paper we show how to achieve similar improvement by relaxing the integral constraint only. This is important in applications involving hazard function and likelihood ratios where negative density estimates are awkward to handle.
#### Article information
Source
Ann. Statist., Volume 8, Number 5 (1980), 1160-1163.
Dates
First available in Project Euclid: 12 April 2007
https://projecteuclid.org/euclid.aos/1176345153
Digital Object Identifier
doi:10.1214/aos/1176345153
Mathematical Reviews number (MathSciNet)
MR585714
Zentralblatt MATH identifier
0459.62031
JSTOR
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https://chemistry.stackexchange.com/questions/82531/how-do-you-tell-whether-fluorine-goes-to-axial-or-equatorial-position-in-iodine?noredirect=1
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# How do you tell whether fluorine goes to axial or equatorial position in iodine dioxide difluoride?
I need to find the $\ce{F-I-F}$ bond angle of $\ce{[IO2F2]^-}$. But the thing is I can put 2 fluorines in the equatorial or axial positions so I get 3 different answers. I'm guessing they're all three different molecules with slightly different properties and I have to pick out the most stable one. Looking it up on the internet I find the two in axial position which I guess is because the two fluorines pull charge towards themselves and repel the other fluorine so they want to stay far away from each other, am it right?
As we are deaing with a single 4e3c bond, iodine will need to be hybridised as $\mathrm{sp^2}$ or less. This means we have one direction (axial) with a $\mathrm p$ type bonding orbital and one (equatorial) with something like $\mathrm{sp^2}$ or similar. We can now use Bent’s rule to deduce that fluorine should occupy the axial positions as it is the more electronegative substituent.
We could also have arrived there by realising that oxygen hardly ever takes part in 4e3c bonds. These bonds are basically the incorporation of a central atom into an existing $\ce{X-X}$ bond on a formal basis. Oxygen, however, needs two electrons per atom to reach an octet meaning that there needs to be another additional bond. This cannot be the case in simple compounds such as $\ce{IO2F2-}$.
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https://quant.stackexchange.com/questions/16181/swaption-model-for-forward-swap-rate/16563
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# swaption model for forward swap rate
I have another question about interest rates. In this case it is about swaption and how to come up with a pricing formula. For the rest of my question I use the notation from Brigo. The payoff of a payer swaption discountad from the maturity $T_\alpha$ to the current time $t$ is given by
$$D(t,T_\alpha)N\left(\sum^\beta_{i=\alpha +1 }P(T_\alpha,T_i)\tau_i(F(T_\alpha;T_{i-1},T_i)-K)\right)^+$$
where
• $D(t,T_i)$ the discount factor at $t$ of time $T_i$
• N some notional
• $\tau_i$, general daycount convention for between $T_{i-1}$ and $T_i$
• $F(T_\alpha;T_{i-1},T_i)$ forward rate at $T_\alpha$ between $T_{i-1}$ and $T_i$
• strike rate $K$
• $P(T_\alpha,T_i)$ zero coupon bond at $T_\alpha$ with maturity $T_i$.
denoting with $S:=S_{\alpha,\beta}(0)$ the forward swap rate, i.e. that $K$ which makes the contract fair $(=0)$ we can come up with models for $S$. Assuming a log normal model we derive a Black like formula.
However, I'm interested in the case where $dS=\sigma dW$, i.e. $S$ is normally distributed (Bachelier model). How does a pricing forumla for a swaption look like? I just can find Black formula on the web. Many thanks for the reference / answer.
One can write for the payoff of an swaption $$\sum_i\tau_i P_{i+1}(S_{\alpha,\beta}(T_\alpha)-K)^+$$ and therefore the pricing equation follows Joshi's explainations. To derive the above equation use that the swap rate is given by $$S_{\alpha,\beta} = \sum_i \frac{\tau_iP_{i+1}}{\sum_i\tau_iP_{i+1}}F^i,$$ where $F^i$ are the corresponding forward rates.
well just take the Bachelier formula with $r=d=0$ $S_0 = S_{\alpha,\beta}$ and then multiply by the annuity.
The annuity will be $$\sum \limits_i \tau_i P_{i+1}.$$ where $P_{i+1}$ is the df for $t_{i+1}.$
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http://mathhelpforum.com/calculus/115605-integral-result-help.html
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Math Help - Integral Result help!
1. Integral Result help!
I am confused how to integrate the equation below the result
should be /6 ???
$\int\limits_{0}^{1}\frac{1}{\sqrt{4-x^2}}\, dx$
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http://clay6.com/qa/37453/express-the-given-complex-number-in-the-form-a-bi-i-i-
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Browse Questions
# Express the complex number $i^{9}+i^{19}$ in the form $a+bi$
$(a)\;3\qquad(b)\;1\qquad(c)\;0\qquad(d)\;2$
Explanation :
$i^{9} + i^{19} = i^{4\times 2 + 1 } + i^{4 \times 4 + 3}$
$= (i^4)^{2}\;.i +(i^{4})^{4} \;.i^{3}$
$= 1 \times \;.i + 1 \times \;.(-i) \qquad [i^{4} = 1\;, i^{3} = -i]$
$=i - i$
$=0$
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https://www.dept.aueb.gr/en/mbc-event-created/year
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# Event Calendar
## Event Calendar
The Department of Marketing and Communication
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https://www.zora.uzh.ch/id/eprint/135005/
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# On the computation of finite bottom-quark mass effects in Higgs boson production
Mueller, Romain; Öztürk, Deniz Gizem (2016). On the computation of finite bottom-quark mass effects in Higgs boson production. Journal of High Energy Physics, 2016(8):55.
## Abstract
We present analytic results for the partonic cross-sections contributing to the top-bottom interference in Higgs production via gluon fusion at hadron colliders at NLO accuracy in QCD. We develop a method of expansion in small bottom-mass for master integrals and combine it with the usual infinite top-mass effective theory. Our method of expansion admits a simple algorithmic description and can be easily generalized to any small parameter. These results for the integrated cross-sections will be needed in the computation of the renormalization counter-terms entering the computation of finite bottom-quark mass effects at NNLO.
## Abstract
We present analytic results for the partonic cross-sections contributing to the top-bottom interference in Higgs production via gluon fusion at hadron colliders at NLO accuracy in QCD. We develop a method of expansion in small bottom-mass for master integrals and combine it with the usual infinite top-mass effective theory. Our method of expansion admits a simple algorithmic description and can be easily generalized to any small parameter. These results for the integrated cross-sections will be needed in the computation of the renormalization counter-terms entering the computation of finite bottom-quark mass effects at NNLO.
## Statistics
### Citations
Dimensions.ai Metrics
21 citations in Web of Science®
21 citations in Scopus®
### Altmetrics
Detailed statistics
Item Type: Journal Article, refereed, original work 07 Faculty of Science > Physics Institute 530 Physics Physical Sciences > Nuclear and High Energy Physics English 2016 13 Feb 2017 15:21 01 Apr 2020 22:39 Springer 1029-8479 Gold Publisher DOI. An embargo period may apply. https://doi.org/10.1007/JHEP08(2016)055
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http://www.justinmath.com/vertex-form/
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# Vertex Form
To easily graph a quadratic equation, we can convert it to vertex form:
$y=a(x-h)^2+k$
In vertex form, we can tell the coordinates of the vertex of the parabola just by looking at the equation: the vertex is at $(h,k)$. We can also tell which way the parabola opens, by checking whether $a$ is positive (opens up) or negative (opens down).
\begin{align*} \textbf{Given Equation} \hspace{.5cm} & \hspace{.5cm} \textbf{Vertex} \hspace{.5cm} && \hspace{.5cm} \textbf{Opens} \\ y=(x-2)^2+1 \hspace{.5cm} &\Bigg| \hspace{.5cm} (2,1) \hspace{.5cm} &&\Bigg| \hspace{.5cm} \text{up} \\ y=-2(x-5)^2-3 \hspace{.5cm} &\Bigg| \hspace{.5cm} (5,-3) \hspace{.5cm} &&\Bigg| \hspace{.5cm} \text{down} \\ y=7(x-1)^2+\frac{1}{2} \hspace{.5cm} &\Bigg| \hspace{.5cm} \left( 1, \frac{1}{2} \right) \hspace{.5cm} &&\Bigg| \hspace{.5cm} \text{up} \\ y=-\frac{1}{3} \left( x+\frac{2}{7} \right)^2-\frac{4}{5} \hspace{.5cm} &\Bigg| \hspace{.5cm} \left( -\frac{2}{7}, -\frac{4}{5} \right) \hspace{.5cm} &&\Bigg| \hspace{.5cm} \text{down} \end{align*}
To convert a quadratic equation into vertex form, we can complete the square.
\begin{align*} \text{Original equation} \hspace{.5cm} &\Bigg| \hspace{.5cm} y=2x^2-4x-5 \\ \text{Divide by } 2 \hspace{.5cm} &\Bigg| \hspace{.5cm} \frac{y}{2}=x^2-2x-\frac{5}{2} \\ \begin{matrix} \text{Move the constant to} \\ \text{the other side} \end{matrix} \hspace{.5cm} &\Bigg| \hspace{.5cm} \frac{y}{2}+\frac{5}{2}=x^2-2x \\ \text{Add } \left( \frac{-2}{2} \right)^2 = 1 \text{ to both sides} \hspace{.5cm} &\Bigg| \hspace{.5cm} \frac{y}{2} + \frac{7}{2} =x^2-2x+1 \\ \text{Factor} \hspace{.5cm} &\Bigg| \hspace{.5cm} \frac{y}{2} + \frac{7}{2} =(x+1)^2 \\ \text{Multiply by } 2 \hspace{.5cm} &\Bigg| \hspace{.5cm} y+7 =2(x+1)^2 \\ \text{Subtract } 7 \hspace{.5cm} &\Bigg| \hspace{.5cm} y =2(x+1)^2-7 \\ \end{align*}
Practice Problems
Write the equation in vertex form $y=a(x-h)^2+k$. Then, find the coordinates of the vertex and tell which way the parabola opens. (You can view the solution by clicking on the problem.)
$1) \hspace{.5cm} y=x^2+2x+3$
Solution:
$y=(x+1)^2+2$
$(-1,2) \hspace{.5cm} \text{up}$
$2) \hspace{.5cm} y=x^2-6x+4$
Solution:
$y=(x+1)^2+2$
$(3,-5) \hspace{.5cm} \text{up}$
$3) \hspace{.5cm} y=2x^2+20x-5$
Solution:
$y=2(x+5)^2-55$
$(-5,-55) \hspace{.5cm} \text{up}$
$4) \hspace{.5cm} y=-3x^2+6x+1$
Solution:
$y=-3(x-1)^2+4$
$(1,4) \hspace{.5cm} \text{down}$
$5) \hspace{.5cm} y=2x^2-2x-1$
Solution:
$y=2 \left( x-\frac{1}{2} \right)^2-\frac{3}{2}$
$\left( \frac{1}{2}, -\frac{3}{2} \right) \hspace{.5cm} \text{up}$
$6) \hspace{.5cm} y=-\frac{1}{3}x^2-2x-10$
Solution:
$y=-\frac{1}{3} (x+3)^2 - 7$
$(-3,-7) \hspace{.5cm} \text{down}$
$7) \hspace{.5cm} y=\frac{3}{4}x^2-2x+3$
Solution:
$y=\frac{3}{4} \left( x-\frac{4}{3} \right)^2+\frac{5}{3}$
$\left( \frac{4}{3}, \frac{5}{3} \right) \hspace{.5cm} \text{up}$
$8) \hspace{.5cm} y=-\frac{2}{3}x^2-8x-17$
Solution:
$y=-\frac{2}{3} (x+6)^2 + 7$
$(-6,7) \hspace{.5cm} \text{down}$
Tags:
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http://www.ams.org/joursearch/servlet/DoSearch?f1=msc&v1=14F10&jrnl=one&onejrnl=jams
|
# American Mathematical Society
My Account · My Cart · Customer Services · FAQ
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You are here: Home > Publications
AMS eContent Search Results
Matches for: msc=(14F10) AND publication=(jams) Sort order: Date Format: Standard display
Results: 1 to 3 of 3 found Go to page: 1
[1] Kiran S. Kedlaya. Good formal structures for flat meromorphic connections, II: Excellent schemes. J. Amer. Math. Soc. 24 (2011) 183-229. MR 2726603. Abstract, references, and article information View Article: PDF [2] David Ben-Zvi and Thomas Nevins. Cusps and $\mathcal{D}$-modules. J. Amer. Math. Soc. 17 (2004) 155-179. MR 2015332. Abstract, references, and article information View Article: PDF This article is available free of charge [3] Masaki Kashiwara and Pierre Schapira. Integral transforms with exponential kernels and Laplace transform. J. Amer. Math. Soc. 10 (1997) 939-972. MR 1447834. Abstract, references, and article information View Article: PDF This article is available free of charge
Results: 1 to 3 of 3 found Go to page: 1
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https://brilliant.org/problems/shortest-way-out/
|
# Shortest way out
Geometry Level 2
Above is a cube $$ABCDEFGH$$. $$ABCD$$ is the ceiling, $$EFGH$$ is the floor, and the rest are the walls. Additionally, $$AB = 2$$. A lizard is on point $$F$$ and is wanting to go to point $$A$$. If the lizard can only travel via walls, what is the measure of the shortest distance the lizard can take in order to reach its destination?
The answer can be expressed in the form of $$A + B\sqrt{C}$$ such that $$A$$, $$B$$ and $$C$$ are prime numbers or $$0$$. Find $$A + \frac{C}{B}$$.
×
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http://www.mathworks.com/help/physmod/sm/release-notes.html?requestedDomain=www.mathworks.com&nocookie=true
|
# Simscape Multibody Release Notes
## R2016a
New Features, Bug Fixes
#### SimMechanics renamed to Simscape Multibody
SimMechanics™ software is now named Simscape™ Multibody™. The product library is located in the Simscape node of the Simulink® library browser under the name Multibody. You can open the product library at the MATLAB® command prompt using the `sm_lib` command.
The product library structure has been flattened. Sublibraries previously under SimMechanics Second Generation now appear directly under Multibody. The complete SimMechanics First Generation library is now a Multibody sublibrary named First Generation (1G).
#### Dynamic camera in Mechanics Explorer: Specify camera location and orientation during simulation using key frames
Mechanics Explorer adds dynamic cameras with gradually shifting viewpoints during playback. A Camera manager enables you to create cameras and specify camera pose through keyframes—each a viewpoint attached to a playback time. During playback, Mechanics Explorer interpolates between the various keyframes to obtain smooth camera trajectories.
You can create multiple cameras in a model, each with its own set of keyframes. During playback, you can switch between previously created cameras by using the visualization pane context-sensitive (right-click) menu. If you split the visualization pane into tiles, you can assign different cameras to different tiles. For more information, see:
#### Perspective view in Mechanics Explorer: Enhance three-dimensional quality of animated simulation results
Dynamic cameras capture your model animation using a perspective view. This view enhances the perception of depth by making bodies appear smaller with increasing distance from the dynamic camera. The perspective view is active only in dynamic cameras. The global camera continues to use an orthographic view. The figures compare the perspective and orthographic views of dynamic and global cameras.
Perspective View of Dynamic Cameras
Orthographic View of Global Camera
#### Parameterized models from CAD import: Create parameterized model with option to update parameter values only
Imported models are now parameterized in terms of MATLAB variables defined in a separate data file. The `smimport` function generates the new data file for each model imported and links the two through the model workspace. The data file contains the numerical values of all block parameters, including those parameters left in their default settings.
The `smimport` function provides a new import mode for regenerating data files associated with previously imported models. The new mode provides a limited form of CAD update that updates block parameters but not the block diagram. You specify the new mode by setting the optional `ImportMode` Name,Value pair argument to `dataFile`.
#### CAD joint definitions in Simscape Multibody XML schema: Express CAD joints directly in XML files
The `smimport` function now supports CAD joint definitions in XML import files. To this end, the Simscape Multibody XML schema provides a new Joints parameter section. The Simscape Multibody Link CAD plug-in does not support the new joint definitions, but you can create XML import files from the XML schema directly.
## R2015b
New Features, Bug Fixes
#### Point On Curve Constraint block
Constrain the position of a frame to a specified curve, for example, to model a roller coaster or cam mechanism. You specify a curve using the new Spline block, which you connect to geometry port B. The Point On Curve Constraint block appears in the Constraints library.
The block constrains the attached frame by applying the force needed to keep it on the specified curve. You can sense the constraint force as a three-dimensional vector that the block outputs as a physical signal.
For a tutorial showing how to use the Spline and Point On Curve Constraint blocks, see Model Cam Mechanism.
#### Spline block for specifying curved paths
Specify a 2-D or 3-D curve along which to constrain the position of a frame. Connect the Spline block to geometry port B of a Point On Curve Constraint block in order to constrain a frame to the specified curve. The Spline block appears in the new Curves and Surfaces library.
Spline curves can be open or closed and are based on cubic interpolation between the curve points you specify. You can visualize the spline curve in the Spline block UI, for example, to ensure the curve shape is correct. You can also visualize the spline curve in Mechanics Explorer on model update and during simulation.
For a tutorial showing how to use the Spline and Point On Curve Constraint blocks, see Model Cam Mechanism.
#### Frame creation via Solid block UI
Interactively add frames to a solid using the frame creation interface in the Solid block dialog box. Use the Frames menu to add or edit any number of frames. You can define the frame origin and orientation based on the solid reference frame axes, the solid center of mass and principal axes, or geometric features such as points, lines, and surfaces.
You can use a geometric feature by selecting the Based on Geometric Feature radio button, selecting the desired geometric feature in the visualization pane, and then clicking the Use Selected Feature button. To keep your new frame, save the frame definition and select OK or Apply.
For a tutorial showing how to use the frame creation interface, see Interactively Create Solid Frames.
#### Mechanics Explorer link to block diagram
Go to the block corresponding to a node on the tree view pane in Mechanics Explorer. You can select a solid in the visualization pane, right-click the highlighted node in the tree view pane, and then select Go to Block. You can also select other node types directly from the tree view pane, such as those corresponding to subsystems, joints and constraints, forces and torques, and other blocks. For more information, see Go to Block from Mechanics Explorer.
#### Rotation Sequence option in Rigid Transform block
Specify a 3-D rotation as a sequence of three elementary rotations. Such rotation sequences are commonly known as Euler and Tait-Bryan sequences. The rotation sequence parameterization is available in the Rigid Transform block. It is also available in joint blocks with spherical joint primitives, including Spherical Joint, 6-DOF Joint and Telescoping Joint.
#### Featured example
A new featured example showcases the Point-on-Curve Constraint and Spline blocks:
## R2015a
New Features, Bug Fixes
#### Visibility setting to show or hide solids, bodies, and multibody subsystems in Mechanics Explorer
Switch the visibility of a solid, body, or multibody subsystem on or off in Mechanics Explorer. A new context-sensitive menu in the tree-view pane enables you to:
• Show the selected component
• Hide the selected component
• Show only the selected component
• Show all the components in the model
To switch the visibility setting, in the tree-view pane of Mechanics Explorer, right-click the name of a solid, body, or multibody subsystem. Then, select the desired option from the context-sensitive menu. For more information, see Filtering Model Visualization.
The Joints library adds a Lead Screw Joint block. Use this block to convert rotational motion to translational motion and, conversely, translational motion to rotational motion. Lead screw applications include the linear actuators typically used in aircraft flap systems, CNC machines, and 3-D printers. The block is based on a new joint primitive named Lead Screw Primitive (LS).
#### Constant Velocity Joint block
The joints library adds a Constant Velocity Joint block. Use this block to model a joint with two rotational degrees of freedom—the bend and azimuth angles—and a kinematic constraint that ensures the base and follower port frames spin at constant velocity relative to each other regardless of their relative angle.
Constant velocity joint applications include automotive driveline systems with power transmission occurring between shafts connected at an angle. The block is based on a new joint primitive named Constant Velocity Primitive (CV).
## R2014b
New Features, Bug Fixes
#### Constraint force and torque sensing in Constraint blocks
Compute and output the forces and torques that enable a Constraint block to enforce its kinematic constraint. The blocks output one or more physical signals with the variables that you select. These variables can include the constraint force and torque vectors and their signed magnitudes. The blocks resolve the vector quantities in the resolution frame that you specify.
The new blocks with constraint force and torque sensing are Angle Constraint and Distance Constraint. These blocks expand the list of blocks with constraint force and torque sensing. You can also sense constraint forces and torques through Joint blocks.
#### Solid 3-D visualization in Solid block dialog box
Visualize the solid you are modeling directly in the Solid block dialog box. The updated block includes a collapsible visualization pane that shows the current state of your 3-D solid. You can use this pane to check the geometry and color of individual solids before updating or simulating the model.
The visualization pane includes a toolstrip for controlling the solid view. The toolstrip, which provides many of the Mechanics Explorer toolstrip buttons, enables you to rotate, pan, and zoom a solid, to select a standard view point, and to visualize the solid reference frame.
#### Rotation matrix parameterization in Rigid Transform and Joint blocks
Specify a frame rotation using a 3-D rotation matrix. The new parameterization is available in two block types, Rigid Transform and joint blocks with spherical joint primitives. Use this parameterization in the Rigid Transform block to specify a fixed rotation or in a joint block to specify the position state target of a spherical joint primitive. The joint blocks with the new parameterization are:
#### Featured example
A new featured example showcases the constraint force and torque sensing capability of Joint blocks:
## R2014a
New Features, Bug Fixes
#### STEP file import
Load solid geometry directly from a STEP file. This file type enables SimMechanics to automatically compute inertia from solid geometry, an advantage over STL files. You can generate the STEP file that you want to load externally, e.g., using a CAD platform.
#### Total and constraint force and torque calculation in joint blocks
Sense the total and constraint forces and torques acting at whole joints. Joint block dialog boxes provide a new expandable parameter list, Composite Force/Torque Sensing, in which you can select the whole-joint variables to sense. Select a variable to calculate its time-dependent values during simulation and deliver them through a physical signal output port. Variables that you can sense include:
• Total Force/Torque — Net sum of forces and torques acting at the joint. These variables include contributions from actuation, internal mechanics, and constraint forces and torques.
• Constraint Force/Torque — Forces and torques acting orthogonally to the joint degrees of freedom. In a Revolute Joint block, which provides a single rotational degree of freedom about the Z axis, the constraint forces act along all the Cartesian axes (X, Y, and Z), while the constraint torques act about the X and Y axes.
#### Time-varying gravity option in Mechanism Configuration block
Specify the gravitational acceleration vector as a function of time, using the Mechanism Configuration block. To support this task, the Uniform Gravity parameter in the block dialog box now provides a `Time-Varying` option. Select that option to expose a physical signal port to which you can connect a time-varying gravity physical signal. The gravitational acceleration vector is strictly uniform in space. It does not vary with position.
#### Gravitational Field block
Model the gravitational pull of a point mass on every rigid body in a mechanism. The Gravitational Field block exerts a force that varies with mass and distance according to Newton's law of universal gravitation. Applications include large-scale orbital systems in which gravity changes due to varying distances play an important role—e.g., a solar system model for spacecraft trajectory planning. The block is in the Forces and Torques library.
#### Animation at arbitrary speed in Mechanics Explorer
Change the base playback speed of a SimMechanics animation by an arbitrary factor. This speed corresponds to the 1x animation slider setting in Mechanics Explorer. It equals the number of seconds in simulation time that play in one second of animation playback time.
You can specify the base playback speed as a numerical input in Mechanics Explorer. This parameter appears in Tools > Animation Settings. Change its value to better visualize motion at extreme time scales.
The new parameter is relevant, for example, in a solar system model. At the default value of the base playback speed, planet motion is exceedingly slow. Due to the time scale of such a model, moving the playback speed slider to its maximum value of 256× does not suffice. Planet motion remains nearly imperceptible.
To visualize one Earth revolution in minutes or seconds, you must increase the playback speed by a very large factor. This factor might be seven orders of magnitude larger than the default value—larger than the playback speed slider allows. You specify such a large playback speed using the new base playback speed parameter.
Consider a model of the solar system. You can play animation at a rate of one Earth revolution per second. To play animation at this rate, you specify a base playback speed of
`$365\frac{\text{days}}{\text{second}}\text{\hspace{0.17em}}·\text{\hspace{0.17em}}24\frac{\text{hours}}{\text{day}}\text{\hspace{0.17em}}·\text{\hspace{0.17em}}60\text{\hspace{0.17em}}\frac{\text{minutes}}{\text{hour}}\text{\hspace{0.17em}}·\text{\hspace{0.17em}}60\frac{\text{seconds}}{\text{minute}}=3.15e7.$`
You can then use the playback speed slider to fine-tune the playback speed. The slider multiples the base playback speed by factors of two between a minimum of 1/256 and a maximum of 256.
## R2013b
New Features, Bug Fixes
#### Joint blocks that now permit prescribed motion defined as an input signal
Joint blocks now accept motion variables—position, velocity, acceleration—as actuation inputs. Use these inputs to specify the time-dependent path of a joint directly.
#### Actuation force and actuation torque calculation for prescribed motion
Joint blocks can now compute and output actuation force and torque values. Use these outputs to analyze actuation force and torque requirements at a joint, for example, due to prescribed motion.
The import function for second-generation models, `smimport`, supports three additional CAD constraints: parallel, perpendicular, and distance. Imported models represent parallel and perpendicular constraints using Angle Constraint blocks, and distance constraints using Distance Constraint blocks.
#### Bevel Gear Constraint block
The Gears and Couplings library contains one new block:
#### Featured examples
Two new featured examples are available:
## R2013a
New Features, Bug Fixes
#### Common Gear block
SimMechanics provides a new Common Gear Constraint block. You can find this block in the new Gears, Couplings and Drives library.
BlockDescription
Common GearGear constraint that you can use to transmit angular motion between two rigid body frames rotating about parallel axes
#### Rack and Pinion block
SimMechanics provides a new Rack and Pinion Constraint block. You can find this block in the new Gears, Couplings and Drives library.
BlockDescription
Rack and PinionGear constraint that you can use to convert the angular motion of a pinion frame into linear motion of a rack frame and vice-versa
#### Pin Slot Joint block
SimMechanics provides a new Pin Slot Joint block. You can find this block in the Joints library.
BlockDescription
Pin Slot JointJoint with two degrees of freedom, one translational and one rotational, with mutually orthogonal motion axes
#### Internal Force block for modeling action and reaction forces
SimMechanics provides a new Internal Force block. You can find this block in the Forces and Torques library.
BlockDescription
Internal ForceGeneral force acting between two rigid body frames along the line connecting their origins
#### Published XML Schema for model import, enabling users to import mechanical models from external applications such as CAD systems
SimMechanics now provides an XML schema that you can use to generate SimMechanics Import XML files. Use the schema in conjunction with the API of an external application, such as a CAD platform, to generate a valid SimMechanics Import XML file for a multibody model. Then, import this file to automatically generate an equivalent model in SimMechanics Second Generation format.
#### Higher Gravity Precision
The gravity vector in the Mechanics Configuration block now has a precision of six significant digits (`-9.80665 m/s^2`). Older models with a Mechanism Configuration block retain the older precision level of three significant figures. To apply the higher precision level in these models, you can manually update the gravity vector.
#### SimMechanics Generation Comparison
The Gears library adds to SimMechanics Second Generation new complex constraints previously found only in SimMechanics First Generation. For a full comparison between the two SimMechanics generations, see Modeling with SimMechanics First and Second Generations.
#### Featured examples
Four new featured examples are available:
## R2012b
New Features, Bug Fixes, Compatibility Considerations
#### Second Generation technology now supporting CAD import from SolidWorks, Inventor, and Pro/ENGINEER
SimMechanics introduces CAD import in SimMechanics second-generation format. Import the SimMechanics Import XML file that represents a CAD assembly, and automatically generate the corresponding SimMechanics second-generation model.
#### Second Generation technology now supporting C-code generation with Simulink Coder
SimMechanics Second Generation now supports code generation with Simulink Coder™. Generate C code from a SimMechanics model, and use the code for applications like hardware-in-the-loop (HIL) testing and rapid prototyping.
SimMechanics Second Generation does not support run-time parameters. Model parameters are fixed during code generation, and are not available for edit outside SimMechanics. To update model parameters, you must edit them in SimMechanics and then regenerate the C code for your model.
#### Solid of revolution geometry in Solid block
The Solid block adds a `Revolution` geometry. The geometry represents solids that have a constant cross-section about an axis of revolution. Examples include cones, domes, and toroids. Revolutions can be full or partial.
#### Changes to inertia specification
The form of the Products of Inertia input vector has changed in Solid and Inertia blocks. The new input vector has the form [Iyz, Izx, Ixy]. The vector elements correspond to the inertia matrix off-diagonal elements:
`$\left(\begin{array}{ccc}& {I}_{xy}& {I}_{zx}\\ {I}_{xy}& & {I}_{yz}\\ {I}_{zx}& {I}_{yz}& \end{array}\right)$`
Previously, the Products of Inertia parameter required the negative values [-Iyz, -Izx, -Ixy].
#### Four new examples
SimMechanics introduces four new examples:
## R2012a
New Features, Bug Fixes, Compatibility Considerations
#### SimMechanics Version 4.0 Software and Second Generation Technology
SimMechanics Version 4.0 introduces Second Generation technology to model, simulate, and analyze two- and three-dimensional multi-body mechanical systems. Second Generation technology provides a more intuitive and powerful block diagram language that lets you easily create reusable parts and libraries. It also adds advanced three-dimensional visualization and animation support.
Version 4.0 provides full support for both First Generation and Second Generation functionality, including block sets and tools. With Version 4.0, you have the option to create and simulate a mechanical model using First or Second Generation technology. Version 4.0 software gives you the two full block libraries, labeled First Generation and Second Generation.
Note: The term generation — e.g. "Second Generation" — refers to the SimMechanics technology used. A SimMechanics version may contain one or both generations.
#### SimMechanics First and Second Generation Technologies
SimMechanics Second Generation technology is a comprehensive advancement of SimMechanics First Generation technology. To ease the transition from First Generation to Second Generation technology, and to support existing First Generation users, SimMechanics Version 4.0 fully supports both First Generation and Second Generation features.
This table summarizes First Generation and Second Generation technologies in their native SimMechanics versions.
TechnologyDescriptionBlock Library
SimMechanics First GenerationEncompasses the complete SimMechanics behavior through Version 3.2.3 (R2011b). First Generation features are designated by the First Generation library in both the Simulink Library Browser and the Help Browser windows.To access the block library, at the command line, type `mechlib`.
SimMechanics Second GenerationEncompasses the new SimMechanics behavior in Version 4.0 (R2012a). Second Generation features are designated by the Second Generation library in both the Simulink Library Browser and the Help Browser windows.To access the block library, at the command line, type `sm_lib`.
#### Compatibility Considerations
First- and second-generation blocks are based on different languages. To interconnect the two block types, you must use Simulink-PS Converter and PS-Simulink Converter blocks. You can find the converter blocks in the Simscape Utilities library.
#### Improvements in SimMechanics Second Generation Technology
The following functionality has been added or improved for SimMechanics Second Generation:
• Multibody modeling paradigm centered on frames, including:
• Ports and nodes map that directly to frames
• Frames that are strictly locally-defined
• Mechanics Explorer visualization utility
• Visualize 3–D models
• Explore model using tree browser and visualization panes
• Enhanced animation support
• Control animation speed
• Replay animation without rerunning simulation
• Inertia calculation and joint state targets
• Automatically calculate inertia from geometry
• Specify joint state target values and priority settings
• Improved integration with Simscape.
• Includes support for physical signals and units.
#### Common Functionality in SimMechanics First and Second Generation Technologies
The following functionality is present in both SimMechanics First and Second Generations:
• Rigid body specification
• Joint specification
• Constraint specification
• Force and torque inputs
• Linearization of mechanical models
• Trimming mode of analysis
• Motion outputs
#### Functionality Found Only in SimMechanics First Generation Technology
The following functionality is present only in SimMechanics First Generation:
• Code generation support
• Model reference accelerator mode is absent in the SimMechanics Second Generation sub-library.
• Motion input in Joint Blocks
• Force outputs in Joints and Constraints blocks
• Missing Constraints blocks:
• point-curve, gear, velocity, and projection constraints are not included in the SimMechanics Second Generation sub-library.
• Missing Force Outputs
• Applied and reaction force outputs for joints are not available.
• Missing Joints
• Screw and massless connector joint blocks are not included in the SimMechanics Second Generation sub-library.
• Variable gravity and mass distribution
• Visualization features
• Model reference normal mode is not included in SimMechanics Second Generation technology.
Bug Fixes
## R2011a
No New Features or Changes
## R2010b
No New Features or Changes
## R2010a
New Features
#### Optional Simplification of Subsystem Hierarchy During Model Import
When you generate SimMechanics models with the `mech_import` command, you can now choose certain automatic simplifications of the imported model's hierarchy:
• Bringing all joints in the generated model to the highest level being imported, either the whole model or a subsystem.
• Grouping all welded bodies at each level of the model hierarchy into new rigid subsystems at the same level.
Without these options, the generated model's hierarchy follows the hierarchy specified in the imported XML file, derived from its original CAD assembly.
#### "What's This?" Context-Sensitive Help Available for Import Physical Modeling XML Dialog Box
This release introduces "What's This?" context-sensitive help for parameters that appear in the Import Physical Modeling XML dialog opened by entering `mech_import` with no arguments at the command line. This feature provides quick access to a detailed description of the parameters, saving you the time it would take to find the information in the Help browser.
To use the "What's This?" help, do the following:
1. Place your cursor over the label of a parameter.
2. Right-click. A What's This? context menu appears.
For example, the following figure shows the What's This? context menu appearing after a right-click on the Start time parameter in the Solver pane.
3. Click What's This? A context-sensitive help window appears showing a description of the parameter.
#### Connection Port Block Consolidated to Simscape Library and Documentation
The Connection Port block has been removed from the block libraries of all add-on products dependent on Simscape software. When using these dependent add-on products, look for the Connection Port block in the Simscape Utilities library.
The Connection Port block help for these add-on products now directs you to the Simscape block reference.
#### New Demos
Two new demos have been added.
### Model Hierarchy Simplification During Import
You can learn more about how to simplify imported model hierarchy by reviewing the Mechanical Import with Model Simplification featured example.
This demo uses two new Physical Modeling XML files, `SimplificationExample1.xml` and `SimplificationExample2.xml`. Models generated from these XML files also appear as large graphics examples in Nondefault Hierarchy and Organization of Generated Models.
### Reference Coordinate Systems in Imported Physical Modeling XML
With the SimMechanics Link utility, you can export reference coordinate systems that you insert into CAD assemblies. (This feature is not supported on all CAD platforms.) From the exported Physical Modeling XML, you can generate a SimMechanics model with extra Body coordinate systems corresponding to the assembly reference coordinate systems and not associated with CAD constraints and automatically generated Joints.
Using the new `GearAssembly.xml` file, the User-Added Coordinate Systems in an Imported Gear Assembly featured example shows how you can use reference coordinate systems to manually add a Constraint block to a model after import.
## R2009b
No New Features or Changes
## R2009a
New Features
#### Changes to External Virtual Reality Visualization
The new Simulink 3D Animation software replaces the Virtual Reality Toolbox™ product for visualizing virtual scenes. The documentation section on building and using a virtual reality client to visualize SimMechanics models has been updated to reflect this change.
#### Pro/ENGINEER CAD Translation Case Study
The CAD translation chapter now contains a case studycase study demonstrating assembly export and re-export, along with model import and update. The study uses SimMechanics and SimMechanics Link software, together with Pro/ENGINEER®, and models a double pendulum, subsequently modified to a triple pendulum. The study illustrates how you can update an existing generated CAD-based model with successive changes to the original CAD assembly.
## R2008b
New Features, Compatibility Considerations
#### New SimMechanics Visualization and Animation
The visualization has been upgraded with new features and a new interface. It now supports
• Customizable body geometries with STL (stereolithographic) files
• Customizable body colors
• Better dynamic view control
• Better animation speed control
Consult the new SimMechanics Visualization and Import Guide for complete information.
For more about creating STL files, see BodyBuilder for Creating STL Body Geometry Files following.
#### Compatibility Considerations
The old SimMechanics visualization allowed you to save visualization settings to a MAT-file associated with a SimMechanics model.
When you open such a model in the new version, the model will attempt to load the MAT-file, as before, and map the old visualization options to the new options as closely as possible. This is a one-time conversion. The MAT-file has to be on the MATLAB path so it can be found when you open the model.
To save these converted visualization settings:
1. You must open the visualization window and save these settings to the model.
2. Then you must save the model itself.
Use the visualization controls to save the settings to the model. See the SimMechanics Visualization and Import Guide.
Caution To save visualization settings from an old model in the new visualization, you must follow these steps, in this order. Otherwise, you might lose the old settings permanently.
### Compressed Animation Recording from New Visualization on Windows Vista and 64-Bit Windows Operating Systems
To compress a recorded animation of a simulation, you need the Indeo 5 codec. This codec might not be available on the 32-bit Windows Vista™ operating system and the 64-bit Windows® XP and Windows Vista operating systems. If you require compression and the codec is not found, the animation AVI file is still saved, but without compression. A warning appears.
For further details, consult Technical Solution 1-1HTNHW at the MathWorks® web site.
### New Visualization Window Status Bar Not Available on Intel Mac Operating System
The status bar of the new visualization window, below the machine display, does not appear at all on the Intel® Mac operating system. On other operating systems, the status bar shows simulation time, as well as Body block and coordinate system names.
### New Visualization Not Supported on Solaris 64 UNIX Operating System
The new visualization and animation interface is not available on the Solaris 64 UNIX operating system. SimMechanics software automatically reverts to the old visualization interface.
The new SimMechanics Link utility provides a bridge from third-party mechanical design and modeling applications to the system and control design features of MATLAB and Simulink. It connects computer-aided design (CAD) platforms to mechanical modeling with SimMechanics software by enabling export of CAD assemblies into the Physical Modeling XML format that allows for automatic generation of SimMechanics models.
#### Upgraded Mechanical Import and Automatic Model Generation
The new `mech_import` command works with externally defined Physical Modeling XML files to automatically generate SimMechanics models. It supports a new SimMechanics feature, updating models generated previously.
#### Compatibility Considerations
Physical Modeling XML files generated by the old CAD-to-SimMechanics translators remain compatible with `mech_import`. Using this command, you can still import old XML files to generate SimMechanics models. Because these models have no associated exported STL body geometry files, they will visualize using the standard (noncustom) body shapes.
The updating feature of `mech_import` works only with Physical Modeling XML files generated by exporting from the SimMechanics Link utility. This feature does not work with Physical Modeling XML files generated from the old CAD-to-SimMechanics translators.
You should replace all existing instances of the `import_physmod` command with the new `mech_import` command. See Command Being Removed following.
Caution Do not attempt to use the `import_physmod` command in older SimMechanics versions with Physical Modeling XML files generated by the new SimMechanics Link exporter.
#### BodyBuilder for Creating STL Body Geometry Files
In addition to generating STL body geometry files automatically from a CAD assembly, you can also create STL files by hand or by using a body geometry editor. BodyBuilder is an application based on MATLAB that provides a graphical means to create STL files for use in SimMechanics body visualization. You can obtain BodyBuilder from MATLAB Central.
#### Command Being Removed
Command NameWhat Happens When You Use Command?Use This InsteadCompatibility Considerations
`import_physmod`Still runs`mech_import`Replace all existing instances of `import_physmod` with `mech_import`.
#### SimMechanics Documentation Reorganized
The SimMechanics documentation is now organized into four books.
BookIncludes Material from Old Chapters
SimMechanics Getting Started Guide1, 2, and 3
SimMechanics User's Guide4, 5, 8, and 9
SimMechanics Visualization and Import Guide6 and 7
SimMechanics Reference10, 11, 12, and 13
#### Pro/ENGINEER CAD Translation Case Study
A new CAD translation case study, available from MATLAB Central, demonstrates assembly export and re-export, along with SimMechanics model import and update, using SimMechanics and SimMechanics Link software. The study is based on Pro/ENGINEER and models a double pendulum, subsequently modified to a triple pendulum. The study illustrates how you can update an existing generated CAD-based model with successive changes to the original CAD assembly.
## R2008a
New Features
#### "What's This?" Context-Sensitive Help Available for Simulink Configuration Parameters Dialog
R2008a introduces "What's This?" context-sensitive help for parameters that appear in the Simulink Configuration Parameters dialog. This feature provides quick access to a detailed description of the parameters, saving you the time it would take to find the information in the Help browser.
To use the "What's This?" help, do the following:
1. Place your cursor over the label of a parameter.
2. Right-click. A What's This? context menu appears.
For example, the following figure shows the What's This? context menu appearing after a right-click on the Start time parameter in the Solver pane.
3. Click What's This? A context-sensitive help window appears showing a description of the parameter.
## R2007b
New Features
#### Interfacing with One-Dimensional Simscape Domains
The Prismatic-Translational Interface and Revolute-Rotational Interface blocks of the new Interface Elements library allow you to connect a SimMechanics Prismatic or Revolute joint primitive to a Physical Networks line connected to Simscape blocks. The Prismatic-Translational Interface and Revolute-Rotational Interface blocks transfer mechanical velocities and forces/torques as Physical Networks cross- and through-variables, respectively, without energy loss, along or around axes that you can define.
Several new demos illustrate the use of the Interface Elements blocks. See New Demos following.
#### SimMechanics State Names Now Available to Simulink and Real-Time Workshop
You can access the names of the mechanical states of your SimMechanics models through the `mech_stateVectorMgr` command. The names of these states and the SimMechanics blocks that define them are now available to Simulink and appear in the outputs of model simulations. They also appear in simulations based on code generated with Real-Time Workshop.
See the Simulink and Real-Time Workshop documentation for further details about states.
#### Controlling Redundant Constraint Analysis with New Tolerance Setting
You can now adjust the sensitivity of the SimMechanics redundant constraint analysis in the Constraints tab of the Machine Environment block, which allows you to choose between automatic constraint redundancy analysis or specifying a constraint redundancy tolerance explicitly.
Certain mechanical configurations are sensitive to the constraint redundancy tolerance and can spuriously lose or gain degrees of freedom if this tolerance is adjusted incorrectly.
#### New Demos
Nine new demos have been added.
### Interface Blocks
These demos illustrate how to use the new Interface Elements blocks. See Interfacing with One-Dimensional Simscape Domains preceding.
### Car Modeling
These new demos provide examples of sophisticated automotive modeling.
These demos shipped in the Version 2.6 (R2007a) SimMechanics product.
#### Code Generation Documentation Consolidated to Simscape User's Guide
Documentation of code generation features common to all Physical Modeling add-on products based on Simscape software has been consolidated to the Simscape User's Guide. The SimMechanics User's Guide continues to document uniquely SimMechanics features related to code generation.
## R2007a
New Features, Compatibility Considerations
#### SimMechanics Software Now Requires Simscape Product
SimMechanics software now depends on and requires Simscape software, the foundation for Physical Modeling products. Simscape software includes common Physical Modeling utilities and block libraries.
#### Sharing Models Using Simscape Editing Modes
SimMechanics software now features a selection of two Simscape editing modes that allow full or restricted editing of models.
• The Restricted mode requires SimMechanics product to be installed, but does not require a license. It allows you to change a limited set of model parameters, but not the blocks or connections, in a SimMechanics model.
• The Full mode requires both Simscape and SimMechanics products to be installed. It allows you to change anything in a SimMechanics model.
#### Block Library Links Must Be Resolved
All SimMechanics blocks in your models must now have resolved block library links. You can neither disable nor break these library links. This is a global Simscape requirement. Consult the Simscape documentation for further details.
#### Compatibility Considerations
If you have an existing SimMechanics model with disabled or broken links from SimMechanics blocks to the SimMechanics block library, you must restore all the broken block library links for your model to be valid.
If you have disabled or broken the SimMechanics library link for blocks that you have customized and want to keep these modified blocks in your model, you must move these modified blocks to your own custom library or libraries, then copy the block instances that you need to your model.
You must still restore the block link to its parent library, whether that parent is the SimMechanics block library or your own.
#### Two Blocks Now with Tunable Parameters
These SimMechanics parameters are now tunable from their respective block dialogs:
#### Demos Expanded
Five new demos have been added.
### Angular Motion Equivalence
The `mech_gimbal_transform` demo shows the equivalence of a body's angular motion as measured by Joint Sensors and as measured by Body Sensors.
### Joint Limits
Two demos illustrate how to model limits or clearance on joint motion:
The first illustrates limits on translational motion; the second, limits on rotational motion.
### Stochastic Oscillator and Controller
Two demos simulate a mixture of deterministic and random forces with a model of a micromechanical damped linear oscillator:
The first model has no controller; the second, a control force in addition to the damped spring and white noise forces.
#### Modeling Constraints with SimMechanics Software
A new MATLAB Digest article explains how to model mechanical constraints with SimMechanics blocks. The article uses a set of four existing SimMechanics demos as illustrations.
## R2006b
New Features, Compatibility Considerations
#### Computer-Aided Design Translator for Pro/ENGINEER Available via the Web
A new computer-aided design (CAD) Pro/ENGINEER-to-SimMechanics translator is available. You install and use this translator with Pro/ENGINEER. It is independent of MATLAB.
The translator converts a Pro/ENGINEER CAD machine assembly into an XML file in the Physical Modeling format. The XML file represents the assembly in a form that you can use to generate a SimMechanics block diagram model dynamically equivalent to the original CAD assembly. To generate models, use the `import_physmod` command.
### Installing the Pro/ENGINEER-to-SimMechanicsTranslator
Obtain and use the installer executable by locating and downloading its archive at `www.mathworks.com/products/simmechanics/`. A README page is provided that describes installation and configuration details.
### Translator Documentation
Help files accompany the Pro/ENGINEER-to-SimMechanics translator. They include two HTML pages and a PDF book. These files are independent of the MATLAB help system.
### Translator Examples
Some examples of Pro/ENGINEER CAD assemblies are included with the Pro/ENGINEER-to-SimMechanics translator.
One of the examples is a robot arm assembly. The corresponding XML file in Physical Modeling format, `robot.xml`, is located in the `toolbox/physmod/mech/mechdemos/` folder, relative to your MATLAB root.
#### Compatibility Considerations
Versions of Pro/ENGINEER compatible with the Pro/ENGINEER-to-SimMechanics translator are listed at the MathWorks Web site. The translator is available only for the Microsoft Windows (32-bit) operating system.
#### SolidWorks-to-SimMechanics Translator Now Available Only via the Web
The existing SolidWorks®-to-SimMechanics translator for the SolidWorks CAD platform continues to be available via the Web, at `www.mathworks.com/products/simmechanics/`. However, it no longer ships with the SimMechanics product.
#### Compatibility Considerations
Versions of SolidWorks compatible with the SolidWorks-to-SimMechanics translator are listed at the MathWorks Web site.
The SolidWorks CAD platform and the SolidWorks-to-SimMechanics translator are available only for the Microsoft Windows (32-bit) operating system.
#### New Demo
This version of SimMechanics software includes one new demo model, `mech_brownian_osc`, a stochastic linear harmonic oscillator based on micro- and biomechanics.
#### Modeling Flexible Bodies with SimMechanics Software
A new MATLAB Digest article and related technical paper explain how to simulate flexible bodies with SimMechanics models and third-party finite element analysis applications. A set of models accompanies the technical paper in a compressed zip archive available from MATLAB Central.
## R2006a
New Features
#### New Block Dialogs and the Simulink Model Explorer
Most of the SimMechanics block dialogs have been upgraded and are now compatible with the Simulink Model Explorer. See the Simulink documentation for more about Model Explorer.
### Block Dialogs Not Rendered in Model Explorer
Model Explorer cannot render the dialogs of these blocks:
#### Joint Spring & Damper Adds Extra Simulink State When Connected to a Revolute
Each Joint Spring & Damper block connected to a revolute primitive now adds a Simulink state to your model. These states are in addition to other normal Simulink states, such as those associated with Integrator and Transfer Fcn blocks. See the Simulink documentation for more about Simulink model states.
This new feature does not change the mechanical states of your model, those associated with SimMechanics joint blocks. See the `mech_stateVectorMgr` command reference for more about mechanical states.
The SolidWorks-to-SimMechanics translator and Physical Modeling XML import command have been improved. See Importing Mechanical Models and the `import_physmod` command reference in the SimMechanics User's Guide.
• Mates in a CAD assembly (restrictions on the free motion of CAD parts) are now translated into Joint blocks that reflect a particular combination of joint primitives, such as Prismatic, Revolute, Spherical, Bushing, etc. Previously, all degrees of freedom in a CAD assembly were translated into appropriately configured Custom Joint blocks. Rigid connections between parts continue to be translated into Welds.
• Blocks in SimMechanics models generated from Physical Modeling XML files are now, by default, labeled with shorter names. You can change the naming convention in the `import_physmod` command options.
## R14SP3
New Features
#### New Shared Environment Block
The new Shared Environment block allows you to link two separate SimMechanics block diagrams with a nonphysical connection. The block enforces the same machine environment settings on both machines but adds no mechanical components (bodies or degrees of freedom) to either. Two machines so connected require exactly one Machine Environment block, rather than two.
See the Shared Environment block reference for further details.
#### Updated Body Spring & Damper Block
The Body Spring & Damper block no longer contains any degrees of freedom.
Previous versions of the Body Spring & Damper block contained six degrees of freedom (DoFs) represented by a Joint. This Joint had to be taken into account when counting DoFs and loops in your model.
The new Body Spring & Damper block instead uses a Shared Environment block to connect the two sides and contains no DoFs. See their respective block references for more information.
#### Normalizing Rotations
The Body dialog accepts various rotational forms (Euler angles, rotation matrix, quaternion). The Body block now interprets these rotational forms in a slightly different way, so that the standard normalization conditions on rotation matrices and quaternions are consistently enforced. As a result, you might now see slightly different simulation results from earlier versions.
#### New State Vector Commands
Four new SimMechanics commands allow you to manipulate the mechanical states of your models. See the command references for more.
#### New import_physmod Dialog
The `import_physmod` command generates SimMechanics models from Physical Modeling XML files. In addition to importing Physical Modeling XML through the command line, you can now set up the command through a dialog.
See the `import_physmod` command reference for further information.
#### Demos Expanded
Two new demos have been added:
The second demo has an associated MAT-file.
#### Documentation Enhancements
The SimMechanics User's Guide has been enhanced.
• The review on representing motion has been revised.
• The analyzing motion has been revised.
• The computer-aided design (CAD) documentation (also available as a separate book) has been significantly revised. See the CAD chapter.
• A new chapter of case studies, based on the Stewart platform, has been added. The studies apply advanced methods and tasks to this system. SimMechanics software includes a related set of demo model and library files.
• Degrees of freedom, states, closed topology, and constraints
• Trimming and linearization
• Designing controllers for the platform
• Generating code versions of the model
• Implementing code on dedicated hardware (hardware in the loop)
## R14SP2
New Features
#### Demos Expanded
Two new demos have been added:
Each demo has an associated MAT-file.
These demos illustrate static friction (stiction) implemented with the Joint Stiction Actuator.
#### Documentation Enhancements
The online SimMechanics Help has been enhanced with links to four new Web-based AVI animation files (one of them new in this release) that record SimMechanics simulations.
You can access these links most easily by using the Examples index in the Help browser, under Prerecorded Animations.
## Compatibility Summary
ReleaseFeatures or Changes with Compatibility Considerations
R2016aNone
R2015bNone
R2015aNone
R2014bNone
R2014aNone
R2013bNone
R2013aNone
R2012bChanges to inertia specification
R2012aSimMechanics First and Second Generation Technologies
R2011bNone
R2011aNone
R2010bNone
R2010aNone
R2009bNone
R2009aNone
R2008b
R2008aNone
R2007bNone
R2007aBlock Library Links Must Be Resolved
R2006b
R2006aNone
R14SP3None
R14SP2None
|
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http://mathhelpforum.com/differential-equations/195493-reoccurance-relation-differential-equation.html
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## from reoccurance relation to a differential equation
Hi,
say I have a reoccurance relation:
$a_{t+1} = f(a_t)$
and I want to try and solve it as a differential eq:
$\frac { da_t }{ dt }\cong \frac { a_{ t+1 }-a_{ t } }{ \Delta t } =\frac { f(a_{ t })-a_{ t } }{ \Delta t } =...$
What $\Delta t$ do I take? can I just use $\Delta t = 1 ..?$
thank you
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https://tex.stackexchange.com/questions/324160/make-bottom-margin-smaller-while-using-div-calc?answertab=oldest
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# Make bottom margin smaller while using div=calc
Problem: the bottom margin is too large, i.e. I want the text to run further towards the footer, i.e. closer to the footer rule in the example below, but still keep div=calc such that the rest fits as it does now. Minimum Working Example showing the problem:
\documentclass[DIV=calc, paper=a4, fontsize=11pt, twocolumn]{scrartcl}
\usepackage{lipsum}
\usepackage{fancyhdr}
\pagestyle{fancy}
\usepackage{lastpage}
\lfoot{}
\cfoot{}
\rfoot{\footnotesize Page \thepage\ of \pageref{LastPage}}
\renewcommand{\footrulewidth}{0.4pt}
\begin{document}
\lipsum[1-8]
\end{document}
One solution is to add footheight=0mm to the options of \documentclass{scrartcl}:
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https://math.stackexchange.com/questions/304314/the-set-of-all-functions-from-mathbbn-to-0-1-is-uncountable
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# The set of all functions from $\mathbb{N} \to \{0, 1\}$ is uncountable?
How can I prove that the set of all functions from $\mathbb{N} \to \{0, 1\}$ is uncountable?
Edit: This answer came to mind. Is it correct?
This answer just came to mind. By contradiction suppose the set is $\{f_n\}_{n \in \mathbb{N}}$. Define the function $f: \mathbb{N} \to \{0,1\}$ by $f(n) \ne f_n(n)$. Then $f \notin\{f_n\}_{n \in \mathbb{N}}$.
• Think about binary expansion of real numbers. Or look for the duplicate. – Julien Feb 14 '13 at 21:11
• @user62268 yeah that works, i posted the same – Dominic Michaelis Feb 14 '13 at 21:24
• Your answer that came to mind is correct, and in fact is exactly Cantor's diagonalization argument for the power set of natural numbers being larger than the set of natural numbers itself. – Joe Z. Feb 14 '13 at 21:28
You can proof it by contraposition. I will identify the functions with sequence so $a_{n}$=$a(n)$. Now lets say it's countable, now let $a_{nk}=a_k(n)$ be the $k$-th function. Now we construct the function $$b(k)=\left\{ \begin{array}{rl} 1 & a_{kk}=0\\ 0& a_{kk}=1\end{array}\right.$$ You should be able to do the rest.
• You don't need contraposition. You can do a direct proof that goes like this: Let $f$ be a mapping from $\mathbb N$ to $2^{\mathbb N}$. We can construct an element $b$ of $2^{\mathbb N}$ just as you did: $b(k) = 1-f(k)(k)$, and show that $b$ is not in the range of $f$. Therefore $f$ is not a bijection. But $f$ was completely general, so we have just proved that no mapping from $\mathbb N$ to $2^{\mathbb N}$ is a bijection, QED. – MJD Feb 14 '13 at 22:25
Hint: Show that $\{0,1\}^\mathbb N$ is equinumerous with $\mathcal P(\mathbb N)$ and use Cantor's theorem to conclude there is no bijection between $\mathbb N$ and $\mathcal P(\mathbb N)$.
Hint : use the diadic developpement of elements of $[0,1]$.
Hint: Each function from $\mathbb{N} \to \{0, 1\}$ is isomorphic to a subset of $\mathbb{N}$. Simply count $n \in \mathbb{N}$ to be part of the subset of $f(n) = 1$.
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https://socratic.org/questions/53925f1802bf340c005307a5#104733
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Chemistry
Topics
# Question #307a5
Jun 8, 2014
${\text{PbI}}_{2}$ would not form ions in the ionic equation.
#### Explanation:
$P b {I}_{2}$ would not form ions in the ionic equation.
The ionic equation for the example above is $P {b}^{2 +} \left(a q\right) + 2 {I}^{-} \left(a q\right) \to P b {I}_{2} \left(s\right)$
The way to reduce a full balanced symbol equation to an ionic equation is to remember that when in solution, the ions present are free to move around independently therefore anything with an (aq) state symbol can be written as independent ions rather than as a compound:
Like so: $P {b}^{2 +} \left(a q\right) + 2 N {O}_{3}^{-} \left(a q\right) + 2 {K}^{+} \left(a q\right) + 2 {I}^{-} \left(a q\right)$
$\to P b {I}_{2} \left(s\right) + 2 {K}^{+} \left(a q\right) + 2 N {O}_{3}^{-} \left(a q\right)$
Now cancel any spectator ions - those which are the same, with the same state symbol, on both sides of the equation, and you have the ionic equation.
##### Impact of this question
29059 views around the world
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http://www.download-now.net/Minnesota/differentiation-of-error-function.html
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Address Rogers, MN 55374 (763) 428-7677
# differentiation of error function Minnetonka Beach, Minnesota
This directly results from the fact that the integrand e − t 2 {\displaystyle e^{-t^ − 2}} is an even function. This usage is similar to the Q-function, which in fact can be written in terms of the error function. Handbook of Differential Equations, 3rd ed. Google search: Google's search also acts as a calculator and will evaluate "erf(...)" and "erfc(...)" for real arguments.
Why are so many metros underground? Dit beleid geldt voor alle services van Google. Zwillinger, D. Weisstein. "Bürmann's Theorem" from Wolfram MathWorld—A Wolfram Web Resource./ E.
Springer-Verlag. IEEE Transactions on Communications. 59 (11): 2939–2944. PARI/GP: provides erfc for real and complex arguments, via tanh-sinh quadrature plus special cases. comm., May 9, 2004).
Laden... New York: Gordon and Breach, 1990. Sloane, N.J.A. W.
Integrals and Series, Vol.2: Special Functions. W. Note that some authors (e.g., Whittaker and Watson 1990, p.341) define without the leading factor of . derivatives error-function share|cite|improve this question edited Apr 23 at 9:02 kamil09875 4,3592729 asked Apr 23 at 7:44 Rakesh 11 The error function erf($x$) is just $\frac{2}{\sqrt\pi}\int_0^xe^{-t^2}\ dt$, so its
Engineering and Design Solutions 10.954 weergaven 23:29 Gaussian - Duur: 4:28. Washington, DC: Hemisphere, pp.385-393, 1987. Boston, MA: Academic Press, p.122, 1997. Orlando, FL: Academic Press, pp.568-569, 1985.
Steve Grambow 22.895 weergaven 9:49 Approximation of Error in Hindi - Duur: 42:24. The integrand ƒ=exp(−z2) and ƒ=erf(z) are shown in the complex z-plane in figures 2 and 3. New York: Chelsea, 1999. Some authors discuss the more general functions:[citation needed] E n ( x ) = n ! π ∫ 0 x e − t n d t = n ! π ∑
Step-by-step Solutions» Walk through homework problems step-by-step from beginning to end. Asymptotic expansion A useful asymptotic expansion of the complementary error function (and therefore also of the error function) for large real x is erfc ( x ) = e − Wolfram Education Portal» Collection of teaching and learning tools built by Wolfram education experts: dynamic textbook, lesson plans, widgets, interactive Demonstrations, and more. Conf., vol. 2, pp. 571–575. ^ Van Zeghbroeck, Bart; Principles of Semiconductor Devices, University of Colorado, 2011. [1] ^ Wolfram MathWorld ^ H.
What Was "A Lot of Money" In 1971? Another approximation is given by erf ( x ) ≈ sgn ( x ) 1 − exp ( − x 2 4 π + a x 2 1 You can only upload photos smaller than 5 MB. See also Related functions Gaussian integral, over the whole real line Gaussian function, derivative Dawson function, renormalized imaginary error function Goodwin–Staton integral In probability Normal distribution Normal cumulative distribution function, a
Je moet dit vandaag nog doen. Hardy, G.H. Beoordelingen zijn beschikbaar wanneer de video is verhuurd. Because these numbers are not symbolic objects, you get the floating-point results:A = [erf(1/2), erf(1.41), erf(sqrt(2))]A = 0.5205 0.9539 0.9545Compute the error function for the same numbers converted to symbolic objects.
A complex generalization of is defined as (39) (40) Integral representations valid only in the upper half-plane are given by (41) (42) SEE ALSO: Dawson's Integral, Erfc, Erfi, Fresnel Integrals, Gaussian For integer , (16) (17) (18) (19) (Abramowitz and Stegun 1972, p.299), where is a confluent hypergeometric function of the first kind and is a gamma function. The defining integral cannot be evaluated in closed form in terms of elementary functions, but by expanding the integrand e−z2 into its Maclaurin series and integrating term by term, one obtains ISBN 978-0-486-61272-0.
The denominator terms are sequence A007680 in the OEIS. MathWorks does not warrant, and disclaims all liability for, the accuracy, suitability, or fitness for purpose of the translation. Help answer pleaseeeeeeee? It is an entire function defined by (1) Note that some authors (e.g., Whittaker and Watson 1990, p.341) define without the leading factor of .
doi:10.1090/S0025-5718-1969-0247736-4. ^ Error Function and Fresnel Integrals, SciPy v0.13.0 Reference Guide. ^ R Development Core Team (25 February 2011), R: The Normal Distribution Further reading Abramowitz, Milton; Stegun, Irene Ann, eds. Retrieved 2011-10-03. ^ Chiani, M., Dardari, D., Simon, M.K. (2003). Wolfram|Alpha» Explore anything with the first computational knowledge engine. Prudnikov, A.P.; Brychkov, Yu.A.; and Marichev, O.I.
so the integrand is exp(-v^2). The error function has special values for these parameters:[erf(sym(0)), erf(sym(Inf)), erf(sym(-Inf))]ans = [ 0, 1, -1]Compute the error function for complex infinities. Washington, DC: Hemisphere, pp.385-393 and 395-403, 1987. For previous versions or for complex arguments, SciPy includes implementations of erf, erfc, erfi, and related functions for complex arguments in scipy.special.[21] A complex-argument erf is also in the arbitrary-precision arithmetic
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http://pfam.xfam.org/family/COX3
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Please note: this site relies heavily on the use of javascript. Without a javascript-enabled browser, this site will not function correctly. Please enable javascript and reload the page, or switch to a different browser.
60 structures 8530 species 5 interactions 13171 sequences 10 architectures
# Summary: Cytochrome c oxidase subunit III
Pfam includes annotations and additional family information from a range of different sources. These sources can be accessed via the tabs below.
This is the Wikipedia entry entitled "Cytochrome c oxidase subunit III". More...
# Cytochrome c oxidase subunit III
Cytochrome c oxidase III
Identifiers
Symbols COX3; COIII; MTCO3
External IDs GeneCards: COX3 Gene
EC number 1.9.3.1
Orthologs
Species Human Mouse
Entrez 4514 17710
Ensembl ENSG00000198938 ENSMUSG00000064358
UniProt P00414 P00416
RefSeq (mRNA) YP_003024032 n/a
RefSeq (protein) YP_003024032 NP_904334
Location (UCSC) Chr MT:
0.01 – 0.01 Mb
Chr MT:
0.01 – 0.01 Mb
PubMed search [1] [2]
Cytochrome c oxidase subunit III
Structure of the 13-subunit oxidized cytochrome c oxidase.[1]
Identifiers
Symbol COX3
Pfam PF00510
InterPro IPR000298
PROSITE PDOC50253
SCOP 1occ
SUPERFAMILY 1occ
TCDB 3.D.4
OPM superfamily 4
OPM protein 1v55
CDD cd01665
Cytochrome c oxidase subunit 3 is an enzyme that in humans is encoded by the MT-CO3 gene.[2]
Cytochrome c oxidase subunit III is one of main transmembrane subunits of cytochrome c oxidase.
## Function
Cytochrome c oxidase (EC 1.9.3.1) is the terminal enzyme of the respiratory chain of mitochondria and many aerobic bacteria. It catalyzes the transfer of electrons from reduced cytochrome c to molecular oxygen:
4 cytochrome c+2 + 4 H+ + O2 $\rightleftharpoons$ 4 cytochrome c+3 + 2 H2O
This reaction is coupled to the pumping of four additional protons across the mitochondrial or bacterial membrane.[3][4]
Cytochrome c oxidase is an oligomeric enzymatic complex that is located in the mitochondrial inner membrane of eukaryotes and in the plasma membrane of aerobic prokaryotes. The core structure of prokaryotic and eukaryotic cytochrome c oxidase contains three common subunits, I, II and III. In prokaryotes, subunits I and III can be fused and a fourth subunit is sometimes found, whereas in eukaryotes there are a variable number of additional small subunits.[5]
As the bacterial respiratory systems are branched, they have a number of distinct terminal oxidases, rather than the single cytochrome c oxidase present in the eukaryotic mitochondrial systems. Although the cytochrome o oxidases do not catalyze the cytochrome c but the quinol (ubiquinol) oxidation they belong to the same haem-copper oxidase superfamily as cytochrome c oxidases. Members of this family share sequence similarities in all three core subunits: subunit I is the most conserved subunit, whereas subunit II is the least conserved.[6][7][8]
## Clinical significance
Mutations in mtDNA-encoded cytochrome c oxidase subunit genes have been observed to be associated with isolated myopathy or severe encephalomyopathy. [9]
## Subfamilies
• Cytochrome o ubiquinol oxidase, subunit III IPR014206
• Cytochrome aa3 quinol oxidase, subunit III IPR014246
## References
1. ^ Miki K, Sogabe S, Uno A et al. (May 1994). "Application of an automatic molecular-replacement procedure to crystal structure analysis of cytochrome c2 from Rhodopseudomonas viridis". Acta Crystallogr. D Biol. Crystallogr. 50 (Pt 3): 271–5. doi:10.1107/S0907444993013952. PMID 15299438.
2. ^
3. ^ Michel H (1999). "Cytochrome c oxidase: catalytic cycle and mechanisms of proton pumping--a discussion". Biochemistry 38 (46): 15129–15140. doi:10.1021/bi9910934. PMID 10563795.
4. ^ Wikstrom M, Belevich I, Verkhovsky MI (2006). "Proton-coupled electron transfer drives the proton pump of cytochrome c oxidase". Nature 440 (7085): 829–32. doi:10.1038/nature04619. PMID 16598262.
5. ^ Mather MW, Springer P, Hensel S, Buse G, Fee JA (1993). "Cytochrome oxidase genes from Thermus thermophilus. Nucleotide sequence of the fused gene and analysis of the deduced primary structures for subunits I and III of cytochrome caa3". J. Biol. Chem. 268 (8): 5395–5408. PMID 8383670.
6. ^ Danchin A, Glaser P, Kunst F, Rapoport G, Santana M, Hullo MF (1992). "Molecular cloning, sequencing, and physiological characterization of the qox operon from Bacillus subtilis encoding the aa3-600 quinol oxidase". J. Biol. Chem. 267 (15): 10225–10231. PMID 1316894.
7. ^ Lemieux L, Gennis RB, Chepuri V, Au DC (1990). "The sequence of the cyo operon indicates substantial structural similarities between the cytochrome o ubiquinol oxidase of Escherichia coli and the aa3-type family of cytochrome c oxidases". J. Biol. Chem. 265 (19): 11185–11192. PMID 2162835.
8. ^ Rumbley J, Gennis RB, Garcia-Horsman JA, Barquera B, Ma J (1994). "The superfamily of heme-copper respiratory oxidases". J. Bacteriol. 176 (18): 5587–5600. PMC 196760. PMID 8083153.
9. ^ Horváth, R; Schoser, BG; Müller-Höcker, J; Völpel, M; Jaksch, M; Lochmüller, H (2005). "Mutations in mtDNA-encoded cytochrome c oxidase subunit genes causing isolated myopathy or severe encephalomyopathy". Neuromuscular disorders : NMD 15 (12): 851–7. doi:10.1016/j.nmd.2005.09.005. PMID 16288875.
This tab holds the annotation information that is stored in the Pfam database. As we move to using Wikipedia as our main source of annotation, the contents of this tab will be gradually replaced by the Wikipedia tab.
# Cytochrome c oxidase subunit III
No Pfam abstract.
## Literature references
1. Tsukihara T, Aoyama H, Yamashita E, Tomizaki T, Yamaguchi H, Shinzawa-Itoh K, Nakashima R, Yaono R, Yoshikawa S; , Science 1996;272:1136-1144.: The whole structure of the 13-subunit oxidized cytochrome c oxidase at 2.8 A. PUBMED:8638158 EPMC:8638158
This tab holds annotation information from the InterPro database.
# InterPro entry IPR000298
Cytochrome c oxidase (EC) is the terminal enzyme of the respiratory chain of mitochondria and many aerobic bacteria. It catalyses the transfer of electrons from reduced cytochrome c to molecular oxygen:
4 cytochrome c+2 + 4 H+ + O2 --> 4 cytochrome c+3 + 2 H2O
This reaction is coupled to the pumping of four additional protons across the mitochondrial or bacterial membrane [PUBMED:10563795, PUBMED:16598262].
Cytochrome c oxidase is an oligomeric enzymatic complex that is located in the mitochondrial inner membrane of eukaryotes and in the plasma membrane of aerobic prokaryotes. The core structure of prokaryotic and eukaryotic cytochrome c oxidase contains three common subunits, I, II and III. In prokaryotes, subunits I and III can be fused and a fourth subunit is sometimes found, whereas in eukaryotes there are a variable number of additional small polypeptidic subunits [PUBMED:8383670]. The functional role of subunit III is not yet understood.
As the bacterial respiratory systems are branched, they have a number of distinct terminal oxidases, rather than the single cytochrome c oxidase present in the eukaryotic mitochondrial systems. Although the cytochrome o oxidases do not catalyse the cytochrome c but the quinol (ubiquinol) oxidation they belong to the same haem-copper oxidase superfamily as cytochrome c oxidases. Members of this family share sequence similarities in all three core subunits: subunit I is the most conserved subunit, whereas subunit II is the least conserved [PUBMED:1316894, PUBMED:2162835, PUBMED:8083153].
This entry represents a structural domain found in cytochrome c and ubiquinol oxidase subunit III. The overall structure of these enzymes is similar [PUBMED:11017202].
### Gene Ontology
The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.
# Domain organisation
Below is a listing of the unique domain organisations or architectures in which this domain is found. More...
# Alignments
We store a range of different sequence alignments for families. As well as the seed alignment from which the family is built, we provide the full alignment, generated by searching the sequence database using the family HMM. We also generate alignments using four representative proteomes (RP) sets, the NCBI sequence database, and our metagenomics sequence database. More...
## View options
We make a range of alignments for each Pfam-A family. You can see a description of each above. You can view these alignments in various ways but please note that some types of alignment are never generated while others may not be available for all families, most commonly because the alignments are too large to handle.
Seed
(21)
Full
(13171)
Representative proteomes NCBI
(11262)
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(3530)
RP15
(358)
RP35
(800)
RP55
(1075)
RP75
(1326)
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1Cannot generate PP/Heatmap alignments for seeds; no PP data available
Key: available, not generated, not available.
## Format an alignment
Seed
(21)
Full
(13171)
Representative proteomes NCBI
(11262)
Meta
(3530)
RP15
(358)
RP35
(800)
RP55
(1075)
RP75
(1326)
Alignment:
Format:
Order:
Sequence:
Gaps:
We make all of our alignments available in Stockholm format. You can download them here as raw, plain text files or as gzip-compressed files.
Seed
(21)
Full
(13171)
Representative proteomes NCBI
(11262)
Meta
(3530)
RP15
(358)
RP35
(800)
RP55
(1075)
RP75
(1326)
You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.
MyHits provides a collection of tools to handle multiple sequence alignments. For example, one can refine a seed alignment (sequence addition or removal, re-alignment or manual edition) and then search databases for remote homologs using HMMER3.
# HMM logo
HMM logos is one way of visualising profile HMMs. Logos provide a quick overview of the properties of an HMM in a graphical form. You can see a more detailed description of HMM logos and find out how you can interpret them here. More...
# Trees
This page displays the phylogenetic tree for this family's seed alignment. We use FastTree to calculate neighbour join trees with a local bootstrap based on 100 resamples (shown next to the tree nodes). FastTree calculates approximately-maximum-likelihood phylogenetic trees from our seed alignment.
# Curation and family details
This section shows the detailed information about the Pfam family. You can see the definitions of many of the terms in this section in the glossary and a fuller explanation of the scoring system that we use in the scores section of the help pages.
## Curation
Seed source: Pfam-B_78 (release 1.0) Previous IDs: none Type: Family Author: Finn RD Number in seed: 21 Number in full: 13171 Average length of the domain: 206.40 aa Average identity of full alignment: 41 % Average coverage of the sequence by the domain: 93.84 %
## HMM information
HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 21.0 21.0
Trusted cut-off 21.0 21.0
Noise cut-off 20.9 20.9
Model length: 258
Family (HMM) version: 13
# Species distribution
### Sunburst controls
Show
This visualisation provides a simple graphical representation of the distribution of this family across species. You can find the original interactive tree in the adjacent tab. More...
### Tree controls
Hide
The tree shows the occurrence of this domain across different species. More...
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https://danmackinlay.name/notebook/macos_fs_hacks.html
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# Care and feeding of macOS filesystems
See also command lines it is tedious to remember for general unix/macOS/BSD/etc commands.
Most of these commands are supposed to be run sudo root, and each may irremediably erase your data, the data of your friends, the data of your enemies, and/or the data of complete strangers. I will not be responsible if you interpret this as advice, and you take it and find that you need to go running to the NSA to restore your messages from their backups.
(This was split off from general macOS hacks.)
## Trash bin from the command line
AFAICT tehre are two interchangeable options
brew install macos-trash
## TRIM and SSDs
If you have upgraded or replaced the SSD in an Apple computer, it will need to be TRIM-enabled for performance and lifespan. Note that Samsung models below 860 in particular are suspect, and probably should not be TRIMmed.
sudo trimforce enable
## How do I rsync between macOS and Linux?
Two problems here:
• macOS seems to present weird encoding normalisation
• macOS desktop filesystems are per-default case insensitive and many other modern filesystem are case sensitive.
Both these can lead to confusing file mangling and potentially data loss.
It seems to work better for me if I do rsync from the non apple machine as far as the (2) stuff goes, in that it then seems not to accidentally duplicate things if renames have happened. I should look into this with more precision.
Then you still need to handle the encoding: --iconv=UTF-8,UTF8-MAC
Putting that together
rsync --delete \
--iconv=UTF-8,UTF8-MAC -avz \
mac.local:/path/to/stuff/ /Volumes/syncdrive/
pro-tip: the iconv options are in order LOCAL,REMOTE, not FROM,TO. (Q: How does that work when both are local or both remote but you want different encodings?)
## Arsed FileVault
The best way to make sure nobody reads your confidential data is to make sure you never store it in the first place. Fortunately, there is a solution here - FileVault 2! The encrypted external drives can be delicate. Expect the entire disk full of backups to become unusable next time the cable jiggles, and all your data will be, uh… securely deleted for your convenience.
If you like your data, keep at least two copies, on two different disks, to compensate for this convenience.
But you need to take one more step; in periodically reformatting whichever drive most recently corrupted itself and cloning it, you might find that you can’t even erase it. Instead you will get an error unable to delete core storage logical volume.
diskutil cs list
diskutil cs deleteVolume <UUID>
diskutil cs delete UUID-OF-COREVOLUME-GROUP
That doesn’t work? Boot into Linux and nuke it that way.
Or try this cowboy option:
cat /dev/random > /dev/diskBLAH
^C
## Rebuild Spotlight index
Is Spotlight working?
sudo mdutil -sv /
No? Turn it off and on again
sudo mdutil -E /
## Mounting foreign files systems
What do you have to do to get foreign filesystems to mount using this week?
osxfuse is the infrastructure providing access to a bunch of other file systems. It recently become closed source in a controversial and mildly suspect manner.
Built upon osxfuse are a variety of filesystems of varied quality.
## Burning bootable ISO images to USB
Convert ISO to DMG:
hdiutil convert -format UDRW -o something.img \
something.iso
Find which disk is which:
diskutil list
Say it was /dev/disk3… Unmount and clobber the right one (careful now) with the new dmg:
diskutil unmountDisk /dev/disk3
dd if=./debian-6.0.7-amd64-netinst.img.dmg of=/dev/rdisk3 bs=1m
diskutil eject /dev/disk3
Doing this without intermediate dmg output left as an exercise for the premature optimizer.
## Filesystem updates never triggered
OS X FSEvents bug may prevent monitoring of certain folders OS X has a rarely-occurring bug that causes some folder to get ‘broken’ with regards to file system change monitoring via FSEvents. […]
In case you wonder, the bug is related to case (in)sensitivity of the file system. For certain folders, either realpath or FSCopyAliasInfo APIs report their names in incorrect case. This somehow causes the FSEvents system (used by LiveReload to monitor file system changes) to never report any changes for those folders and their subfolders.
(If you are really curious, more details can be found in Radar #10207999, in rb-fsevents issue #10 and in find-fsevents-bug repository.)
Note: this is not a “rarely occurring bug” in the sense that it sometimes occurs when you capitalise a letter in a filename; AFAICT it is triggered every time. Rather, it is a rarely noticed bug, since I guess either changing capitalisation or running file watchers, or the intersection thereof, is rarely noticed. Regardless, the above diagnoses seem to hold. Delete the offending folder and copy it from elsewhere.
## extended attributes for users
ls -al@
xattr -l
### No comments yet. Why not leave one?
GitHub-flavored Markdown & a sane subset of HTML is supported.
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https://hackingathome.wordpress.com/2017/04/07/boiler-control-to-maintain-a-set-temperature/
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# Boiler Control to Maintain a Set Temperature
I wanted to be able to control my home’s heating from a computer. This post discusses the next phase in that project: a control layer that maintains a specified room temperature using a temperature sensor and the boiler control built in previous articles.
I published the boilerio repository on github that contains the code to do this.
Note that neither the code nor the article come with any warranty: please be careful if you’re using it as you could damage your heating system or create a safety hazard.
# Heating system overview
Our heating system is fairly typical for the UK: an S-plan system using a gas-fired “system” boiler with a pressurised hot water storage vessel. When the thermostats call for heat, water is heated by the boiler and pumped around a series of radiators. As noted in the previous article, we have a Danfoss RX2 receiver whose control protocol I’ve reverse-engineered, so we will use that here to control the boiler.
This article looks at the common but relatively crude control method of simply turning the boiler on/off periodically to maintain a steady temperature. Note that the boiler also has a manually-specified target flow temperature and will modulate the burners to achieve this when it is active.
More advanced controls, possibly the subject of future articles, could adjust boiler settings in response to flow temperature and other variables to ensure the boiler is within its most efficient operating parameters. This requires integration with the boiler’s electronic systems not explored here.
The system has three main components:
1. The thermostat transceiver. Here we’re using simple on/off control by implementing an interface to the Danfoss RX2 receiver. We’ll respond to MQTT messages to allow services to issue commands to the boiler and, for monitoring, publish to an MQTT topic when messages are received over RF.
2. The heating controller. This will be a Python daemon that works towards a temperature setpoint (for now this is a command-line parameter, but in future it will be hooked up to a scheduler) by monitoring the current temperature and deciding how to control the boiler to reach the target.
3. The temperature sensor. I’m using an EmonTH for this that measures and publishes room temperature to MQTT. There are some software tweaks I will discuss below.
# The heating controller
There are three modes of operation in reaching and maintaining temperature: significantly below setpoint, significantly above setpoint, and near the setpoint. The first two cases are easy: the boiler should either be on or off. Within the target zone we can modulate the boiler on/off to produce an average heating input to the room of the desired level: this is a type of pulse-width modulation (PWM) with long pulse durations in the order of minutes.
To decide what the duty-cycle (the fraction of the time boiler is turned on for in the full cycle) should be we need to determine the required heat input for the room using a control mechanism that can ‘find’ the correct value, since it will differ based on various factors including the temperature difference to outside and outside weather, building materials and insulation type, effectiveness of the radiators, losses through pipes, etc.
After trying out a couple of approaches based around incrementally increasing or decreasing the PWM duty-cycle according to the current “error” (difference between target and actual temperature), I learned that using a PID controller is a common approach that can be effective given some tuning. This computes a control variable (in our case the PWM duty cycle) given a process variable (the current temperature), and a setpoint (the target temperature). The output u at time t is given by:
$u(t) = K_pe(t) + K_i\int_0^t e(\tau) d\tau - K_d\frac{de(t)}{dt}$
The PID output combines the error (difference between current value and setpoint), the total error over time (the integral component, which allows the controller to adjust to the current conditions), and the differential (to damp excessive corrections), in an amount that is application specific using the coefficients Kp, Ki, and Kd. An initial implementation is in pid.py in the boilerio repository. It is currently quite basic and could be further refined.
For a more detailed overview of PID controllers, the Wikipedia page is a good place to start, and then Brett Beauregard’s excellent Improving the Beginner’s PID article series and accompanying library for the Arduino provide a good explanation of some of the common issues and solutions with basic PID controllers.
• The output is limited between 0.15 and 1. Values below 0.15 are rounded down to 0 since such a small duty cycle doesn’t give the boiler chance to do anything useful. Different limits may be suitable for different systems.
• The integral component is limited between -1 and +1 to avoid it becoming excessively large in either direction (since it can’t influence the output beyond those limits anyway).
• Unlike many applications of PID controllers where the process variable is actively moved in both directions, we can’t actively cool the room. Therefore, we allow a negative integral that’s larger than one might in other systems, to accommodate the proportional term being too large.
# The simulator
Choosing appropriate coefficients for the PID controller and the efficiency of test/dev cycles were both important challenges. At this time of year there is little opportunity to do real-world testing where the temperature difference between inside and out is very high, and to do such a test is both time-consuming and potentially wasteful of energy. Instead, I decided to write a simple simulator, sim.py, to help with the majority of the debugging and tuning.
There are various tools online for calculating heat loss in your home that take into account the building materials, insulation, windows, ventilation, etc. To estimate heat loss through conduction they look at loss through each building element $Q=UA(T_i-T_O)$; there is then the heat loss through ventilation to add in.
We use an extremely simple model that is sufficient to achieve the goals described above. Firstly we combine the U and A terms in the heat loss formula and assume an average across all building elements. We assume that in each time increment, some fraction of the heat will be lost to the outside and some heat will be gained through transfer from the radiators, each with different efficiencies and therefore coefficients, without considering ventilation separately. The radiator temperature itself is assumed to increase and decrease linearly over a ramp-up and ramp-down time when heating demand is indicated or ceases.
We inject a fake Boiler class that updates the model parameters rather than actually sending commands to the real system, allowing the model to interact with the controller. The code is careful to only get the current time in one place and pass it as a parameter, to make mocking the passage of time easier.
To find a reasonable value for the heat-loss coefficient, I grabbed some real data from my temperature logs and used scipy to do a curve fit. Then, keeping that value constant I did a similar exercise to determine the coefficient for heat transfer from the radiator in the room. These values are obviously very rough; different time periods produced different results as the conditions at the time weren’t known (doors opened/closed, etc.).
# Interfacing the boiler to MQTT
The boilerio repository includes a daemon, boiler_to_mqtt.py, that will interface with a serial port using the protocol implemented in the previous two articles. This, like the other tools, uses a config file to specify the location of the MQTT broker and the topic names to use.
RF messages sent and received are published to the topic specified by info_basetopic in the config file. The published payload contains a JSON message with keys “direction” which is ISSUE or RECV, and “cmd”, which is the command issued or received (ON, OFF, or LEARN). An example payload might be:
{"thermostat": "0x1234", "cmd": "ON", "direction": "RECV"}
Clients can issue commands to the boiler by publishing to the topic specified as the heating_demand_topic in the configuration file. The script expects a JSON payload consisting of an object containing two values: the command (“O” for On, “X” for Off, and “L” for Learn), and the thermostat ID as an integer. A sample payload might be:
{"command": "X", "thermostat": 23123}
See the README.md for more information on using the boiler_to_mqtt.py script if you are using a Danfoss receiver. Alternatively, you can still use the temperature management code but replace this script with something that can control whatever receiver you are using.
# Temperature input
There are several options for temperature input: originally I had put together my own temperature ‘transmitter’ using an AVR microprocessor, a Dallas Instruments DS18B20 and an XBee radio (Sparkfun have a guide on the XBee). If you go down that route be sure to get the right XBee hardware since v1 and v2 are not compatible. I also had issues with an Arduino shield I bought, though breadboarding with Sparkfun’s XBee breakout worked fine.
I have since switched to using the excellent emonTH v2 from OpenEnergyMonitor. These have a simpler RF69 radio, which is all that’s needed (and handily is the same one that supports interfacing with the Danfoss receiver), come pre-assembled, have a lower-power sensor that can also record humidity, and are battery powered. The hardware design and software are open-source.
I did choose to make some modifications to the emonTH and emonhub software. For the emonTH I increased the resolution of the temperature readings, which required a number of updates across the stack:
• Support for setting the resolution in the library for the SI7021 sensor;
• Setting the SI7021 resolution during emonTH startup and reporting hundredths rather than tenths of a degree over RF, which required reprogramming the emonTH using a USB-to-UART adapter;
• Modifying the emonhub configuration to accommodate the change of packet format.
Increasing the resolution of the SI7021 sensor readings will also increase the time taken to acquire those readings, and therefore the overall power consumption, so expect batteries to run out quicker. That being said, the OEM project estimate years of battery life from the default configuration so even at a quarter of that it would still be acceptable to me since I’m using rechargeable batteries anyway.
I also modified the format emonhub uses to post data to MQTT rather than using the pre-existing options of either a single message with a series of values whose order is significant in determining their meaning (the “rx” format), or one message per reading (e.g. to topics like emonth/temperature, emonth/humidity) where the grouping of the messages cannot be reconstructed. My branch of emonhub posts a single MQTT message that has a JSON payload with the group of readings (temperature, humidity, battery voltage, etc.) that were taken simultaneously. This is not strictly necessary but was helpful for other projects.
The modified emonhub, emonTH, and SI7021 code are available from github.
# Real-world testing
I have used this code to control the real boiler a number of times, mostly with overnight tests. With the weather getting warmer, I’ve not been able to get a feel for how it works when it’s really cold outside but, in the situations I’ve used it so far, it seems to have worked well. Generally it maintains the temperature to within ±0.2ºC of the setpoint, which I consider to be a success.
# Next steps
The upcoming good weather will surely slow progress but there is plenty that can still be done: three possible areas to investigate next are:
1. Power measurement. It would be useful to read gas usage automatically to better understand how efficiently gas is being used and what effect change have on this.
2. Scheduling. This isn’t really usable as control requires ssh and command-line knowledge.
3. More advanced integration with the boiler. Monitoring and setting parameters such as target, supply, and return water temperatures and burner on/off.
Hope you found this interesting and/or useful!
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http://mathematica.stackexchange.com/questions/36858/numerically-solving-a-system-of-pdes-where-one-function-is-composed-with-the-oth
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Numerically solving a system of PDEs where one function is composed with the other
I'm trying to solve the following system using NDSolve:
\begin{align} u_t(x,t) &= u_{xx}(x,t) - v(x,t) \\ v_t(x,t) &= u(v(x,t),t) \end{align}
with
$$u_x(-1,t) = 0, \quad u_x(1,t) = 0, \quad u(x,0) = \tanh(10x), \quad v(x,0) = 1/3.$$
I tried the following code in Mathematica 7.
NDSolve[{
Derivative[0, 1][u][x, t] == Derivative[2, 0][u][x, t] - v[x, t],
Derivative[0, 1][v][x, t] == u[v[x, t], t],
Derivative[1, 0][u][-1, t] == 0,
Derivative[1, 0][u][1, t] == 0,
u[x, 0] == Tanh[10 x],
v[x, 0] == 1/3
}, {u, v}, {x, -1, 1}, {t, 0, 5}]
This produces an error: NDSolve::delpde: Delay partial differential equations are not currently supported by NDSolve. I think this is coming from the second differential equation, because if it doesn't have a composition, for example if I change the second equation to
$$v_t(x,t) = u(x,t)+v(x,t),$$
and try the code
NDSolve[{
Derivative[0, 1][u][x, t] == Derivative[2, 0][u][x, t] - v[x, t],
Derivative[0, 1][v][x, t] == u[x, t] + v[x, t],
Derivative[1, 0][u][-1, t] == 0,
Derivative[1, 0][u][1, t] == 0,
u[x, 0] == Tanh[10 x],
v[x, 0] == 1/3
}, {u, v}, {x, -1, 1}, {t, 0, 5}]
then I get a result.
Is there anything I can do to help NDSolve solve the original system (with the composition)?
-
I do not think the error message is right. I think the pde itself is not valid mathematically speaking. You have a dependent variable being treated as independent variable. One can see this more clearly in this example: Clear[u, v, x]; eq1 = u'[x] == u[x] - v[x]; eq2 = v'[x] == u[v[x]]; DSolve[{eq1, eq2}, {u[x], v[x]}, x] the error is DSolve::nestdv: "The expression v[x] has nested dependent variables". Now switch to NDSolve, same system, and now you get the delay error: NDSolve[{eq1, eq2, u[0] == 0, v[0] == 0}, {u[x], v[x]}, {x, 0, 1}] and the error is ... – Nasser Nov 12 '13 at 15:51
... NDSolve::cdelay: The method currently implemented for delay differential equations does not support delays that depend directly on the time variable or dependent variables. so if the same system is not valid to be solved analytically (mathematically speaking), how could it becomes valid to be solved Numerically? (I'd have to ask my teacher when I go to school tomorrow on this and see what he says about this).. either way, what you are to do does not seem to be supported by direct use of NDSolve... – Nasser Nov 12 '13 at 16:24
DEs aren't my specialty either, but I don't think it's obvious that the system in your example wouldn't have a solution. I think all you could say is that DSolve doesn't like the form it's in. – Antonio Vargas Nov 12 '13 at 16:24
DO you have a reference or published examples of such PDE's? (I mean of similar form) to give one an idea of how they can come about. – Nasser Nov 12 '13 at 17:16
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https://catsoop.mit.edu/website
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# CAT-SOOP is an Automatic Tutor for Six-Oh-One Problems
\
/ /\__/\
\__=( o_O )=
(__________)
|_ |_ |_ |_
## WHAT IS IT?
CAT-SOOP is a tool for automatic collection and assessment of online exercises, originally developed primarily for use in MIT's 6.01 (Introduction to Electrical Engineering and Computer Science via Robotics). It has since been used in several courses at MIT and at Olin College.
• Web Site:
• Repository Web Access: https://hz.mit.edu/git/catsoop/catsoop
• IRC: #catsoop on OFTC (irc.oftc.net)
• Mailing lists:
• [email protected], low-volume list for announcements and discussion (subscribe here)
• [email protected] for development-related discussion (subscribe here)
## CAN I USE IT FOR MY COURSE?
Of course! CAT-SOOP is free/libre software, available under the terms of the GNU Affero General Public License, version 3+. Please note that the terms of this license apply to the CAT-SOOP system itself, to any third-party software included with CAT-SOOP, and to any plugins used by the system, but not to any course material hosted on a CAT-SOOP instance, unless explicitly stated otherwise.
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https://pythonhosted.org/nengo/examples/learn_square.html
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Notebook
# Nengo Example: Learning to square the input
This demo shows you how to construct a network containing an ensemble which learns how to decode the square of its value.
In [1]:
import numpy as np
import matplotlib.pyplot as plt
%matplotlib inline
import nengo
<IPython.core.display.Javascript at 0x7f6201f05610>
## Step 1: Create the Model
This network consists of an ensemble A which represents the input, an ensemble A_squared which learns to represent the square, and an ensemble error which represents the error between A_squared and the actual square.
In [2]:
model = nengo.Network()
with model:
# Create the ensemble to represent the input, the input squared (learned), and the error
A = nengo.Ensemble(100, dimensions=1)
A_squared = nengo.Ensemble(100, dimensions=1)
error = nengo.Ensemble(100, dimensions=1)
# Connect A and A_squared with a communication channel
conn = nengo.Connection(A, A_squared)
# Apply the PES learning rule to conn
conn.learning_rule_type = nengo.PES(learning_rate=3e-4)
# Provide an error signal to the learning rule
nengo.Connection(error, conn.learning_rule)
# Compute the error signal (error = actual - target)
nengo.Connection(A_squared, error)
# Subtract the target (this would normally come from some external system)
nengo.Connection(A, error, function=lambda x: x**2, transform=-1)
## Step 2: Provide Input to the Model
A single input signal (a step function) will be used to drive the neural activity in ensemble A. An additonal node will inhibit the error signal after 15 seconds, to test the learning at the end.
In [3]:
with model:
# Create an input node that steps between -1 and 1
input_node = nengo.Node(output=lambda t: int(6*t/5)/3.0 % 2 - 1)
# Connect the input node to ensemble A
nengo.Connection(input_node, A)
# Shut off learning by inhibiting the error population
stop_learning = nengo.Node(output=lambda t: t >= 15)
nengo.Connection(stop_learning, error.neurons, transform=-20*np.ones((error.n_neurons, 1)))
## Step 3: Probe the Output
Let's collect output data from each ensemble and output.
In [4]:
with model:
input_node_probe = nengo.Probe(input_node)
A_probe = nengo.Probe(A, synapse=0.01)
A_squared_probe = nengo.Probe(A_squared, synapse=0.01)
error_probe = nengo.Probe(error, synapse=0.01)
learn_probe = nengo.Probe(stop_learning, synapse=None)
## Step 4: Run the Model
In [5]:
# Create the simulator
with nengo.Simulator(model) as sim:
sim.run(20)
In [6]:
# Plot the input signal
plt.figure(figsize=(9, 9))
plt.subplot(3, 1, 1)
plt.plot(sim.trange(), sim.data[input_node_probe], label='Input', color='k', linewidth=2.0)
plt.plot(sim.trange(), sim.data[learn_probe], label='Stop learning?', color='r', linewidth=2.0)
plt.legend(loc='lower right')
plt.ylim(-1.2, 1.2)
plt.subplot(3, 1, 2)
plt.plot(sim.trange(), sim.data[input_node_probe] ** 2, label='Squared Input', linewidth=2.0)
plt.plot(sim.trange(), sim.data[A_squared_probe], label='Decoded Ensemble $A^2$')
plt.legend(loc='lower right')
plt.ylim(-1.2, 1.2)
plt.subplot(3, 1, 3)
plt.plot(sim.trange(), sim.data[A_squared_probe] - sim.data[input_node_probe]**2, label='Error')
plt.legend(loc='lower right')
plt.tight_layout();
We see that during the first three periods, the decoders quickly adjust to drive the error to zero. When learning is turned off for the fourth period, the error stays closer to zero, demonstrating that the learning has persisted in the connection.
Download learn_square as an IPython notebook or Python script.
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https://www.atlantis-press.com/proceedings/itms-15/25842867
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# Impacts of Residents’ Characteristics on Travel Attitude toward Weather Information: an Analytical and Empirical Study
Authors
Junlong Li, Dawei Chen, Xuhong Li
Corresponding Author
Junlong Li
Available Online November 2015.
DOI
https://doi.org/10.2991/itms-15.2015.57How to use a DOI?
Keywords
Weather information; Travel attitude; Individual characteristics; Stated adaptation surveys
Abstract
To explore the relationship between individual characteristics and residents’ travel attitude toward weather information, the hypothesis of dependence of travel attitude on individual characteristics was formally tested. Stated adaptation surveys were conducted to collect residents’ attitudes toward weather information. Then Statistical analysis of Pearson chi-square independence tests were employed on the basis of empirical data collected in Nanjing, China. Results from both the descriptive analysis and the statistical test confirmed that the individual characteristics mattered and that the likelihood of residents changing their travel behaviors in response to weather information they acquired was highly dependent on some of individual characteristics.
Open Access
Proceedings
2015 International Conference on Industrial Technology and Management Science
Part of series
Publication Date
November 2015
ISBN
978-94-6252-123-0
ISSN
2352-538X
DOI
https://doi.org/10.2991/itms-15.2015.57How to use a DOI?
Open Access
TY - CONF
AU - Junlong Li
AU - Dawei Chen
AU - Xuhong Li
PY - 2015/11
DA - 2015/11
TI - Impacts of Residents’ Characteristics on Travel Attitude toward Weather Information: an Analytical and Empirical Study
BT - 2015 International Conference on Industrial Technology and Management Science
PB - Atlantis Press
SN - 2352-538X
UR - https://doi.org/10.2991/itms-15.2015.57
DO - https://doi.org/10.2991/itms-15.2015.57
ID - Li2015/11
ER -
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https://infoscience.epfl.ch/record/178555
|
Infoscience
Journal article
# VLT adaptive optics search for luminous substructures in the lens galaxy towards SDSS J0924+0219
The anomalous flux ratios between quasar images are suspected of being caused by substructures in lens galaxies. We present new deep and high-resolution H and Ks imaging of the strongly lensed quasar SDSS J0924+0219 obtained using the ESO VLT with adaptive optics and the laser guide star system. SDSS J0924+0219 is particularly interesting because the observed flux ratio between the quasar images vastly disagree with the predictions from smooth mass models. With our adaptive optics observations we find a luminous object, Object L, located similar to 0.3 '' to the north of the lens galaxy, but we show that it cannot be responsible for the anomalous flux ratios. Object L as well as a luminous extension of the lens galaxy to the south are seen in the archival HST/ACS image in the F814W filter. This suggests that Object L is part of a bar in the lens galaxy, as also supported by the presence of a significant disk component in the light profile of the lens galaxy. Finally, we find no evidence of any other luminous substructure that may explain the quasar images flux ratios. However, owing to the persistence of the flux ratio anomaly over time (similar to 7 years), a combination of microlensing and millilensing is the favorite explanation for the observations.
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http://mathoverflow.net/users/32972/oliver-straser
|
# Oliver Straser
less info
reputation
217
bio website donthaveone location University of Freiburg age member for 1 year seen 7 hours ago profile views 737
Phd student at University of Freiburg
Research interests: Topology of singular spaces, perverse sheaves and applications to representation theory.
# 22 Questions
18 Intuition behind the ricci flow 10 A question about multiplication in $G(\mathbb{C}((t)))$ and Affine Grassmannians 9 Algebraic Stratifications of $G$-varieties 8 Kazhdan-Lusztig Polynomials and Intersection Cohomology 7 Characteristic Classes in Geometric Representation Theory
# 1,011 Reputation
+10 Strata of the Affine Grassmannian +50 Learning representation theory of real reductive lie groups +25 Equivariant Formality +5 Quasi-isomorphisms and Subalgebras
8 Introductory References for Geometric Representation Theory 5 Learning representation theory of real reductive lie groups 5 Strata of the Affine Grassmannian 4 Pseudofree $T^2$ actions on spheres 3 Whitney stratification and affine grassmanian
# 27 Tags
25 rt.representation-theory × 17 6 smooth-manifolds × 2 24 ag.algebraic-geometry × 16 5 textbook-recommendation 11 reference-request × 11 5 lie-groups 8 geometric-rep-theory × 8 3 algebraic-groups × 5 8 at.algebraic-topology × 7 3 dg-algebras × 4
# 2 Accounts
MathOverflow 1,011 rep 217 Mathematics 190 rep 5
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http://kea-monad.blogspot.com/2009/03/m-theory-lesson-265.html
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occasional meanderings in physics' brave new world
Name:
Location: New Zealand
Marni D. Sheppeard
## Friday, March 20, 2009
### M Theory Lesson 265
There is a nice series of papers by Godsil et al on combinatorics associated to MUBs. Consider the simple qubit Combescure matrix This is the only choice for the eigenvectors of the Pauli matrix $\sigma_{Y}$ that satisfies the following properties. The Schur multiplication of two matrices simply defines entries by the product of matching entries from the two components $A$ and $B$. That is $M_{ij} = A_{ij} B_{ij}$. Under this product, an inverse for $R_2$ is found relative to the democratic matrix (the Schur identity): An invertible matrix in this sense is type II if $M (M^{-1})^{T} = n I$, where $I$ is the ordinary identity matrix. This works for $R_{2}$, although only $R_{2}^{8} = I$.
A type II matrix is a spin model, in the sense of Jones, if all vectors of the form
$Me_{i} \circ M^{-1}e_{j}$
(for $e_{i}$ the standard basis vectors) are eigenvectors for $M$. One checks that this holds for $R_2$. Note that the Fourier (Hadamard) operator $F_{2}$, although a type II matrix, is not a spin model matrix.
CarlBrannen said...
Nice to see the importance of the Democratic matrix showing up here.
Regarding cosmology, the modification of GR that I believe we have to reach is nicely described in the new PI lecture: Towards the end of the cosmological constant problem! : Niayesh Afshordi
This is a modification of GR. There are two important points of compatibility with the gravity I've been working on from the quantum side: (a) Assumes preferred reference frame, and (b) the added material (which he called aether) propagates faster than light.
March 20, 2009 8:01 PM
CarlBrannen said...
There is a related arXiv paper, 0807.2639
March 20, 2009 8:09 PM
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http://www.koreascience.or.kr/article/ArticleFullRecord.jsp?cn=E1ELAT_2015_v15n3_151
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The Effect of Sub-chronic Whole-Body Exposure to a 1,950 MHz Electromagnetic Field on the Hippocampus in the Mouse Brain
Title & Authors
The Effect of Sub-chronic Whole-Body Exposure to a 1,950 MHz Electromagnetic Field on the Hippocampus in the Mouse Brain
Son, Yeonghoon; Jeong, Ye Ji; Kwon, Jong Hwa; Choi, Hyung-Do; Pack, Jeong-Ki; Kim, Nam; Lee, Yun-Sil; Lee, Hae-June;
Abstract
The increasing use of mobile phones has raised public concern about the possible biological effects of radiofrequency electromagnetic field (RF-EMF) exposure on the human brain. To investigate the potential effect of RF-EMF exposure on the brain, we examined the behaviors and hippocampal morphology of C57BL/6 mice after sub-chronic exposure to RF-EMFs with a relatively high SAR level (5.0 W/kg). We applied a 2-hour daily exposure of WCDMA 1,950 MHz using a reverberation chamber that was designed for whole-body exposure for 60 days. In the behavioral tests, RF-EMF did not alter the physical activity or long-term memory of mice. Moreover, no alteration was found in the neuronal and glial cells in the hippocampus by RF-EMFs. In this study, we showed that sub-chronic whole body RF exposure did not produce memory impairment and hippocampal morphological alteration in C57BL/6 mice.
Keywords
Hippocampus;Memory;Mobile Phone;Radiofrequency Electromagnetic Field;Sub-chronic Exposure;
Language
English
Cited by
References
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J. W. Finnie, Z. Cai, J. Manavis, S. Helps, and P. C. Blumbergs, "Microglial activation as a measure of stress in mouse brains exposed acutely (60 minutes) and long-term (2 years) to mobile telephone radiofrequency fields," Pathology, vol. 42, no. 2, pp. 151-154, 2010.
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|
https://www.gradesaver.com/textbooks/math/other-math/thinking-mathematically-6th-edition/chapter-11-counting-methods-and-probability-theory-11-3-combinations-exercise-set-11-3-page-708/52
|
## Thinking Mathematically (6th Edition)
The order of the chosen employees does not matter. Combinations: ${}_{n}C_{r}=\displaystyle \frac{n!}{(n-r)!r!}$ ${}_{6}C_{3}=\displaystyle \frac{6!}{(6-3)!3!}=\frac{6\times 5\times 4}{1\times 2\times 3}=20$
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https://astronomy.stackexchange.com/questions/24241/altitude-of-midnight-satellite/24262
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# Altitude of Midnight Satellite?
The other night, I observed what I believe must have been a satellite, however it was at 1:30am so I was not sure that this would be possible. Being in the Southern Hemisphere we are just past Summer Solstice, so theoretically it could have been reflecting the sun's light.
There were no flashing lights, just a star-like point of light. As it slowly traveled in a NE direction across the sky, it began to gradually fade as typical of a satellite passing into Earth's shadow.
Based on my observation, I'd like to get an understanding of the approximate minimum altitude of the object that I observed, allowing for it to be out of the shadow of the Earth sunlight. I'm not a mathematician, but using Space Engine with the correct time & location, I had to position the camera to some 7000km in altitude before the sun was visible over the horizon. The object was N to NE from where I observed it, whist the midnight sun would have been shining away at the South Pole.
Date/Time: 27-Dec-2017, ~01:30 local time (GMT + 8) Location of observation: Perth, Western Australia (~32S, 116E) Position in sky : ~ 80 to 60 degrees elevation, moving north due northeast Duration of observation : ~2 to 3 minutes
I'll venture a guess that the 7000 kilometers (your software's camera position) was with respect to the center of the Earth. Using 6371 km as a value for the Earth's radius, that would make the altitude only 629 km, which it turns out is quite a popular altitude for satellites in LEO.
For the simplifying case of midnight, one can draw a simple diagram. I get
$$h = R_{\textrm{Earth}} \left(\frac{1}{\cos(35°)} - 1\right)$$
which is about 1400 km at midnight, and the height will be lower before and after.
I'll wait to hear about the camera "height" and try to find another tool for you to use. Do you ever use Python programming language?
Red dots are Perth at local noon and midnight.
• Thanks, I appreciate the response!I cannot vouch for the accuracy of my coordinate accuracy except to say when I ascend to the required altitude I position the camera as tangential to the horizon as possible (i.e. directly to the ground) before moving the camera backwards. – razeezar Jan 7 '18 at 9:28
• Altitude in the software is indeed ~7,500km above sea level. Below is a link to a screenshot to demonstrate. In hindsight I should have referred to lat & lon in the HUD to get a more accurate positon. Note that the camera has been angled after ascent to include both the sun on the horizon as well as Perth city night lights; FOV has also been adjusted to fit both in the shot: link – razeezar Jan 7 '18 at 9:39
• @razeezar that looks great! i.stack.imgur.com/myVkH.jpg You can consider posting a second, supplemental answer and include it the screen shot, confirming what you've tested. – uhoh Jan 7 '18 at 10:01
• Thanks uhoh. I have also linked the following screenshot using in-the-sky.org link; I have selected a moment of 1:16am; This is around the time when satellites were in the same vicinity of the sky travelling in a similar direction as what I saw (i.e. three FLOCK satellites), except these should have all been invisible as they were at too low an altitude to be illuminated at that time of night. I did not notice any other illuminated moving objects at the time that I observed the object ~2 mins it as moved, then began to fade. – razeezar Jan 7 '18 at 14:46
• I have only just noticed that Space Engine automatically changes distance from sea level to the center of the planet at =>1000km above sea level so you are correct! Therefore the altitude at which sun becomes visible is ~1,130km, which seems to check out Mathematically for ~1:30am. (btw I know a little C/++ but not Python). Based on available satellite data I am yet to identify any satellites that were anywhere near this altitude at this time. – razeezar Jan 7 '18 at 16:01
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https://www.omnicalculator.com/physics/resultant-force
|
# Net Force Calculator
Created by Purnima Singh, PhD
Reviewed by Steven Wooding
Last updated: Oct 19, 2022
Omni's net force calculator allows you to determine the resultant force on a body when several forces act simultaneously on it.
Continue reading this article to know what net force is and how to find the net force on an object. You will also see some examples of net force calculations.
If you need help calculating force from Newton's second law of motion, check out the force calculator.
## What is net force? – Net force definition
When a number of forces act simultaneously on an object or a system, the net force or resultant force is the vector sum of all these forces.
We know that the effect of a force $F$ acting on an object of mass $m$ is to accelerate the object according to the equation:
$\quad a = \frac{F}{m}$
Our magnitude of acceleration calculator is a handy tool in case you want to explore more about acceleration.
The effect of net force would accelerate the object by the same amount as all the actual forces acting on the object. So we can say that the net force is a single force that would produce the same effect as all the forces working together.
Now that we know what net force is, let us understand how to find the net force on an object.
## How to find net force – Net force equation
We know that force is a vector quantity, i.e., we need to specify both the magnitude and direction of a force to give its complete description. This means that we should add the individual forces to find the net force just like we add other vectors (check out the vector addition calculator to learn all about vector addition).
To understand this, let us consider a simple scenario where two forces $F_1$ and $F_2$ are acting on a body from two different directions. We can represent these two forces as two vectors $\overrightarrow{F_1}$ and $\overrightarrow{F_2}$ acting at angles $\theta_1$ and $\theta_2$ (see figure 1).
Using the triangle law of vector addition, we know that if two vectors acting simultaneously on a body can be represented in magnitude and direction by the two sides of a triangle taken in one order, the resultant of these two vectors can be represented in magnitude and direction by the third side of the triangle taken in the opposite order (see the net force diagram in figure 1).
Hence, we get the resultant vector:
$\ \ \overrightarrow{F} = \overrightarrow{F_1} + \overrightarrow{F_2}$
If several forces are acting together (see figure 2), we can apply the polygon rule and write a more general net force formula as:
\begin{aligned} \overrightarrow{F} &= \overrightarrow{F_1} + \overrightarrow{F_2} + \overrightarrow{F_3} + ... + \overrightarrow{F_n}\\ \text{ or:}\\ \overrightarrow{F} &= \sum_{i=1}^\infty \overrightarrow{F_i} \end{aligned}
In the next section, we will see a step-by-step guide to how to find the magnitude and direction of the resultant force?
## How to calculate net force
To get the magnitude of the resultant force $F$, we will use the net force equation. We will first resolve each of the forces $F_1$ and $F_2$ into their respective rectangular components:
$\quad F_{1x} = F_1\cos \theta_1 \\\ \\ \quad F_{1y} = F_1\sin \theta_1$
Similarly, for the force $F_2$, we can write:
$\quad F_{2x} = F_2\cos \theta_2\\\ \\ \quad F_{2y} = F_2\sin \theta_2$
Since the components of a vector are scalar quantities, we can now add them. To find the horizontal component $F_x$ of the resultant force, we will sum all the horizontal components of the individual forces:
$\quad F_x = F_{1x} + F_{2x}$
In the same way, the vertical component will be:
$\quad F_y = F_{1y} + F_{2y}$
Finally, we will calculate the magnitude of the resultant force using:
$\quad F = \sqrt{F_x^2 + F_y^2}$
And the angle of the resultant force with respect to the horizontal axis with:
$\quad \theta = \tan^{-1}\frac{F_y}{F_x}$
For $n$ number of forces, we can write a general formula as:
$\quad F_x = \sum_{i=1}^\infty F_{ix}\\\ \\ \quad F_y = \sum_{i=1}^\infty F_{iy}$
Using the net force formula, we can calculate the magnitude of the resultant force using:
$\quad F = \sqrt{F_x^2 + F_y^2}$
And the angle of the resultant force with respect to the horizontal axis using:
$\quad \theta = \tan^{-1}\frac{F_y}{F_x}$
## Examples of net force calculation
To further understand how to find the resultant force, we will consider two simple examples.
First we will consider a simple case where two forces $\overrightarrow{F_1}$ and $\overrightarrow{F_2}$ are applied to an object in opposite directions such that;
• $|F_1| = 10\ N$ and $\theta_1 = 0 \degree$; and
• $|F_2| = 15\ N$ and $\theta_2 = 180 \degree$.
An example of this case would be when you and your friend are sitting in front of each other and trying to push a book towards each other.
Let us see how to calculate the net force.
1. First, we will find the vertical and horizontal components for both the forces:
• $F_{1x} = 10 \cdot \cos 0 \degree$ and $F_{1y} =10 \cdot \sin 0 \degree$.
$\implies F_{1x} = 10$ and $F_{1y} =0$
• $F_{2x} = 15 \cdot \cos 180 \degree$ and $F_{2y} =15 \cdot \sin 180 \degree$.
$\implies F_{1x} = -15$ and $F_{1y} =0$
2. As the vertical components, $F_{1y}$ and $F_{2y}$ are zero, the vertical component of the resultant force will be zero. We can calculate the horizontal component as:
• $F_x = 10 + (-15)$, or
$F_x = -5\ N$
3. According to the definition of the net force, the magnitude of the resultant force will be:
• $F = \sqrt{F_x^2} = 5\ N$
and the direction will be along the direction of the larger force, i.e., $180 \degree$.
Now let us consider another case where the magnitude of the forces is the same as in the previous example, but now both the forces act in the same direction, i.e., $\theta_1 = \theta_2 = 180 \degree$. For example, when you and your friend try to push a heavy box together. In this case, the net force would be $25\ N$ along the direction of both the forces, i.e., $180 \degree$.
In the next section, we will see how to solve the same problem using our resultant force calculator.
## How to use the net force calculator
Let us see how to use the net force calculator:
1. Enter the magnitude ($|F_1| = 10\ N$ and $|F_2| = 15\ N$) and direction ($\theta_1 = 0 \degree$ and $\theta_2 = 180 \degree$) of different forces acting on the body. The directions are measured with respect to the positive x-axis.
2. You can add data for up to 10 forces; fields will appear as you need them.
3. The resultant force calculator will display the magnitude ($F = 5\ N$) and direction ($\theta = 180 \degree$) of the net force. It will also show the values of the horizontal and vertical components of the resultant force.
To convert between different units of force, head on to Omni's force converter.
## FAQ
### How do I find the resultant force acting on an object?
To find the resultant force or net force acting on an object, follow the given instructions:
1. Determine the horizontal and vertical components of all the individual forces by using the formula;
• Horizontal component –
Fₓ = F cos θ
• Vertical component –
Fᵧ = F sin θ
2. Add the individual horizontal and vertical components to get the horizontal and vertical components of the resultant force.
3. Sum the square of the horizontal and vertical components of the resultant force and take the square root of the result. You will get the magnitude of the resultant force.
### When the net force on an object is zero?
According to Newton's first law of motion, if an object is either at rest or moving in a straight line with constant velocity (no acceleration), the net force on the object is zero.
### What are the units of net force?
The units for net force are the same as the unit of force. The SI unit of the net force is the newton (N), and the cgs unit of the net force is dyne.
### How does net force affect the speed of an object?
From Newton's second law of motion, we know that the acceleration or rate of change of speed of an object is directly proportional to the net force acting on the object.
Purnima Singh, PhD
Force 1 (F₁)
N
Angle 1 (θ₁)
deg
Force 2 (F₂)
N
Angle 2 (θ₂)
deg
You can add up to 10 different forces. Each angle is measured with respect to the positive x-axis.
Resultant force
Horizontal component (Fx)
0.97
N
Vertical component (Fy)
0.26
N
Magnitude of resultant force (F)
1
N
Direction of resultant force (θ)
15
deg
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|
https://ask.sagemath.org/question/51186/question-about-jupyter/
|
I am nearly novice in Sagemath and I would like to ameliorate the display of the cells. For this I would like to install Hide_code but I am on windows 10 and the procedure to follow are written for Linux. My second question is why Jupyter comes on windows ten without view?
edit retag close merge delete
off-topic: in general sage is not "windows friendly", if you can I will recommend to use some linux distribution. I have dual boot with win10 and kubuntu and almost all the time Im in kubuntu. Indeed I have a lot more of useful tools in kubuntu, at least for what I generally do in a computer.
( 2020-05-01 10:52:23 -0500 )edit
I have not enough room and to jump from one system to the other is boring.
( 2020-05-01 17:01:04 -0500 )edit
Installing hide_codeis explained here https://ask.sagemath.org/question/502... why doesn't it work for windows?
( 2020-05-02 05:02:50 -0500 )edit
About "comes without view"; can you explain what you mean?
( 2020-05-02 10:13:36 -0500 )edit
Sorry I am stupid . I finally have understud that to install an additionnal package it was necessary to use sage shell. From notebook I was unable to do it.
( 2020-05-02 16:07:33 -0500 )edit
Sort by » oldest newest most voted
Hello, @Cyrille! I have a quite complicated solution that should work on Windows or any OS. I cannot take credit for it; I just adapted a solution from this site (retrieved on May 2nd, 2020), which in turn comes from this other page (retrieved on May 2nd, 2020). Since I don't know Javascript, it was a really painful process to understand this code and how to use it. Unfortunately, I wasn't able to improve the code (I just adapted it), so maybe you need a more clever person than me.
However, here is what I've got. Write the following Python script in a file, which, for the sake of the discussion, I will call "invisible_cells.py":
from IPython.core.display import display, HTML
def toggle_cell():
tag = HTML("""
<script>
code_show=true;
function toggle_cell() {
if (code_show){
$('div.cell.code_cell.rendered.selected div.input').hide(); } else {$('div.cell.code_cell.rendered.selected div.input').show();
}
code_show = !code_show;
}
$( document ).ready(toggle_cell); </script> <a href="javascript:toggle_cell()">Toggle this cell</a>""") display(tag) def hide_cell(): tag = HTML(""" <script> function hide_cell() {$('div.cell.code_cell.rendered.selected div.input').hide();
}
</script>
<a href="javascript:hide_cell()">Hide permanently</a>""")
display(tag)
This script defined two functions: toggle_cell() will allow you to hide/unhide the contents of a cell, while hide_cell will make it permanently invisible.
You can use these functions as follows. Write the following in a cell:
import invisible_cells as ic
ic.hide_cell()
When you execute that cell, it will show you a link "Hide permanently"; when pressed, it will hide the cell and the link. From that point on, you should use the ic.hide_cell() command at the beginning of every cell you want to hide.
Since permanently hiding a cell is dangerous, I also included the ic.toggle_cell() command. If you use it at the beginning of a cell, when executed, it will show you a link "Toggle this cell", which will hide the cell, but also will show it again, just in case you need to make modifications.
This is the downside of the code: You must press the links in order to hide the cells. If you share this notebook with somebody, or even if you close and then re-open the notebook, the cells will be visible until you press the links to hide them. This is because the Javascript code uses the selected div command, which requires the cell to be activated, which in turn requires the link to be pressed. However, if you find somebody who can program Javascript, you can ask them to change the code so that the code recognizes the cell from which is executed, and automatically hides it.
I hope this helps! I am so sorry i didn't find a better solution.
more
Dsejas You have no reason to be sorry. Your help is particularly valuable.
( 2020-05-02 16:07:24 -0500 )edit
Dsejas I have tried your nice code and ic.hide_cell() works perfectly. But the usage of ic.toggle_cell() is unclear. For instance if I code
ic.toggle_cell()
1+2
I can see the blue Toggle this cell. But when I clic on it nothing special is done. I think I have not well understud the way to use it. Secondly, I wonder if a hide cell could be executed. For instance suppose I make an @interact cell but I do not want the code to be seen --- it's a support for a teaching not for programming. I think also that perhaps it will be nice to replace 'Hide permanently' and by Toggle this cell by small icones, to remove the temptation to see what appen when clicked. In all cases thinks to always answer to my questions. I think SageMAth is an fitted to teach.
( 2020-05-05 22:57:48 -0500 )edit
Hello, @Cyrille! Oops, I did a mistake! The code should be completely functional now. The Toggle this cell button should hide and unhide the contents of the cell.
You can replace the "Toggle this cell" and "Hide permanently" texts with icons. Suppose you have a couple of icons in a folder called "images", and the icons you want to use are called "toggle.png" and "hide.png". You should replace
<a href="javascript:toggle_cell()">Toggle this cell</a>
with
<a href="javascript:toggle_cell()"><img src="images/toggle.png"></a>
and also replace
<a href="javascript:hide_cell()">Hide permanently</a>
with
<a href="javascript:hide_cell()"><img src="images/hide.png"></a>
You will need to distribute the "images" folder with your Jupyter notebook.
( 2020-05-06 17:02:05 -0500 )edit
Instead of using icons, I would use something much more discrete, like
<a href="javascript:hide_cell()">.</a>
This way, instead of "Hide permanenlty", you will see a tiny dot---so tiny that only you will know it's there. If you click on it, the cell will hide.
( 2020-05-06 17:03:59 -0500 )edit
By the way, @Cyrille, there is a much better way to hide the code of an @interact cell: you can use HTML web pages instead of using Jupyter notebooks. Basically, you embed the Sage code inside the HTML code, and you get a website interactive demos. You can find a couple of examples here. I can send you a template that allows you to include Sage code, so that it's invisible, but the interactive controls are visible. I think this will be a very useful solution for you!
Disclaimer: Boht, in Jupyter notebooks and in HTML webpages, a student motivated to find the Sage code will be able to do it eventually. They just have to open the document in a text editor. SageMath is designed for Open Science.
( 2020-05-06 17:32:03 -0500 )edit
|
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|
https://monero.stackexchange.com/questions/6651/my-gui-feels-buggy-freezes-all-the-time
|
# My GUI feels buggy / freezes all the time
I am using the official GUI and using my own (local) node, but it freezes all the time and feels buggy overall. Is there any way to resolve this?
First and foremost, it's important to make sure you're running the latest version (v0.11.1.0 at the time of writing). You can check the version # on the Settings page of the GUI (under Debug info). If you're not running v0.11.1.0, please upgrade first:
How do I upgrade my software to v0.11.1.0?
This is typically caused by monerod using all your CPU during the initial sync (you can also apply this guide if it still feels buggy after you've completed the initial sync). monerod requires CPU because it needs to verify blocks. You can limit monerod's CPU usage as follows.
1. Go to the Settings page of the GUI.
2. Look for the daemon startup flags box.
3. Add this line -> --max-concurrency 1
4. Exit the GUI and make sure to stop the daemon as well.
5. Restart the GUI + daemon.
Step 4 & 5 are needed for the flag from step 3 to take effect. Note that --max-concurrency 1 will limit your CPU usage to 1 thread.
In addition, if you're syncing the blockchain to an HDD, it'd probably be best to lower the size of the batch of blocks (block-sync-size) as well. This is done as follows.
1. Again go to the Settings page of the GUI and look for the daemon startup flags box.
2. Add this line after the --max-concurrency 1 line and make sure there's a space between 1 and - -> --block-sync-size 10
3. Thus, the "full" line in the daemon startup flags box becomes -> --max-concurrency 1 --block-sync-size 10
4. Exit the GUI and make sure to stop the daemon as well.
5. Restart the GUI + daemon.
Step 4 & 5 are again needed for the flag from step 2 to take effect. Note that --block-sync-size 10 will reduce the batch of blocks it syncs to 10 (the default is 20) at a time.
Now, monerod also takes a lot of bandwidth during the initial sync. If you're unable to browse or use any applications that require internet connection, you can limit monerod's bandwidth as follows:
1. Again go to the Settings page of the GUI and look for the daemon startup flags box.
2. Add this line after the --block-sync-size 10 line and make sure there's a space between 0 and - -> --limit-rate 500
3. Thus, the "full" line in the daemon startup flags box becomes -> --max-concurrency 1 --block-sync-size 10 --limit-rate 500
4. Exit the GUI and make sure to stop the daemon as well.
5. Restart the GUI + daemon.
Step 4 & 5 are again needed for the flag from step 2 to take effect. Note that --limit-rate 500 will limit the bandwidth to 500 kB/s.
Note that you can tweak the parameters / flags yourself by adjusting the value.
Lastly, the GUI itself also uses some CPU and memory. You can reduce this by running monerod separately from the GUI during the initial sync. This is done as follows:
[1] Exit the GUI and make sure to stop the daemon as well.
[2] Browse to the directory monerod is located (on Windows & Linux it's the same directory as monero-wallet-gui, whereas on Mac OS X it's -> ~/Applications/monero-wallet-gui.app/Contents/MacOS).
[3a] On Windows, open a new command prompt from the same directory as monerod.exe. This is done by first making sure your cursor isn't located on any of the files and subsequently doing SHIFT + right click. It will give you an option to "Open command window here". If you're using Windows 10, it'll, most likely, give you an option to open the Powershell.
[3b] On Linux and Mac OS X, open a new terminal from the same directory as monerod
[4a] On Windows, type the following command in the command prompt:
monerod.exe --max-concurrency 1 --block-sync-size 10 --limit-rate 500
If that doesn't work in the Powershell, type:
.\monerod.exe --max-concurrency 1 --block-sync-size 10 --limit-rate 500
If that doesn't work either in the Powershell, type:
./monerod.exe --max-concurrency 1 --block-sync-size 10 --limit-rate 500
[4b] On Linux and Mac OS X, type the following command in the terminal:
./monerod --max-concurrency 1 --block-sync-size 10 --limit-rate 500
[5] If you were using a non-default directory for the blockchain, you have to add the --data-dir flag too if you start monerod separately. If you already have monerod running, type exit first to gracefully stop the daemon. This is done as follows:
On Windows, type the following command in the command prompt:
monerod.exe --max-concurrency 1 --block-sync-size 10 --limit-rate 500 --data-dir path\to\your\blockchain
If that doesn't work in the Powershell, type:
.\monerod.exe --max-concurrency 1 --block-sync-size 10 --limit-rate 500 --data-dir path\to\your\blockchain
If that doesn't work either in the Powershell, type:
./monerod.exe --max-concurrency 1 --block-sync-size 10 --limit-rate 500 --data-dir path\to\your\blockchain
On Linux and Mac OS X, type the following command in the terminal:
./monerod --max-concurrency 1 --block-sync-size 10 --limit-rate 500 --data-dir path/to/your/blockchain
[6] Note that, if you're running monerod separately, you have to apply the flags every time you start monerod. Thus, on Windows, probably most convenient to create a shortcut, go to properties, and add the flags after the Target. On Linux and Mac OS X, it's probably most convenient to create a little script.
[7] As a general piece of advice, if you need to shut down your PC, first shut down monerod gracefully by typing exit. Otherwise, you might corrupt the blockchain again and you'd have to start all over again.
[8] You can use status in monerod to verify whether it's fully synced. It's fully synced if your height matches the height displayed on a block explorer like, for instance, XMRchain.net.
[9] Once it's fully synced, open monero-wallet-gui. It'll automatically connect to the monerod that is already running. Note, however, that monero-wallet-gui still has to refresh the wallet, for which it currently uses the same status bar.
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https://www.physicsforums.com/threads/little-integer-problem.86696/
|
# Little integer problem
1. Aug 28, 2005
### sitedesigner
ok,
a/b c/d
a,b,c,d are all integers
b and d are > 0
find a number inbetween a/b and b/d using a,b,c,d that is an irrational number.
thanks :!!)
2. Aug 28, 2005
### CarlB
The difference between the two rational numbers is
$$\frac{ad-bc}{bd}$$
If you can find an irrational number that is smaller than this, you can add it to the lesser of {a/d, b/c}.
Carl
3. Aug 28, 2005
### StatusX
You could pick a strictly increasing curve (like y=x^2, for x>0), find the x values that generate these two fractions as y values, and find the y value for the number halfway (or anywhere) between these two x values. It's a safe bet this will be an irrational number.
4. Aug 28, 2005
### sitedesigner
so that will work for sure carl?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook
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https://brilliant.org/discussions/thread/paying-paradox-help/
|
Let's say you want to buy a $97 shirt. You borrow$50 from Friend 1 and $50 from Friend 2. You buy the shirt and get$3 as change. You keep $1 for yourself, one for Friend 1 and the other for Friend 2. Thus, making your debt to Friend 1$49 and Friend 2 $49 If you add the debts, 49+49, it is 98, and then add your$1 which makes $99. Where is the missing dollar? Note by Abijah Bautista 5 years, 9 months ago MarkdownAppears as *italics* or _italics_ italics **bold** or __bold__ bold - bulleted- list • bulleted • list 1. numbered2. list 1. numbered 2. list Note: you must add a full line of space before and after lists for them to show up correctly paragraph 1paragraph 2 paragraph 1 paragraph 2 [example link](https://brilliant.org)example link > This is a quote This is a quote # I indented these lines # 4 spaces, and now they show # up as a code block. print "hello world" # I indented these lines # 4 spaces, and now they show # up as a code block. print "hello world" MathAppears as Remember to wrap math in $ ... $ or $ ... $ to ensure proper formatting. 2 \times 3 $2 \times 3$ 2^{34} $2^{34}$ a_{i-1} $a_{i-1}$ \frac{2}{3} $\frac{2}{3}$ \sqrt{2} $\sqrt{2}$ \sum_{i=1}^3 $\sum_{i=1}^3$ \sin \theta $\sin \theta$ \boxed{123} $\boxed{123}$ ## Comments Sort by: Top Newest See this as: By adding the debts, you are calculating how much you owe the 2 friends, which is $\98$. This tallies with the amount of money that you have spent or have: $98=97$ (from the shirt you bought) $+1$ (that you kept. ) - 5 years, 9 months ago Log in to reply Ok, so lets think about each person separatedly: (You:0 F1:50 F2:50 shop:0) You take the money: (You:100 F1:0 F2:0 shop:0) You buy the shirt (You:3 F1:0 F2:0 shop:97) You give each one 1 dollar (You:1 F1:1 F2:1 shop:97) You pay the debts (You:1-(49+49) F1:1+49 F:1+49 shop:97) (You:-97 F1:50 F:50 shop:97) I dont see any missing dollar.. In your text you dont take the final payment in account to sum all the money :p Actually the sum is always 100 dollars and you'll end up with a -97 debt just as expected. Anyway why are you adding debts? It doesnt have any meaning :P - 5 years, 9 months ago Log in to reply You should subtract it.. of course! Instead you are adding it.. :) - 5 years, 9 months ago Log in to reply Very good question, all though, I do not believe it works that way sadly. Lets think of it another way: Debt is a separate thing from the money itself, it is how much you owe the person. I don't know exactly why it does this with two people, but it seems to not happen with one person only. This is very interesting. - 5 years, 9 months ago Log in to reply By what Logic are you adding the 1$ to the debt of 98\$ ???
- 5 years, 9 months ago
This problem is very much like this one.
http://en.wikipedia.org/wiki/Missingdollarriddle
- 5 years, 9 months ago
it is with me only...because , from the beginning i don't have any money but bought a shirt with all frnds money. at last i have one dollar with me..thats the missing dollar
- 5 years, 9 months ago
you are supposed to subtract one, not add.
- 5 years, 8 months ago
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http://mathhelpforum.com/calculus/134687-find-work-done-stretching-spring.html
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# Math Help - find the work done by stretching a spring..
1. ## find the work done by stretching a spring..
im not sure if i did this problem right, something tells me i didnt do it right...could you check my work? thanks in advance.
IMG.pdf
2. the key here is to treat the natural length of the spring (no stretch) as $x = 0$
stretching the spring 5 cm beyond its natural length ...
$k = \frac{F}{x} = \frac{30 \, N}{.05 \, m} = 600 \, \frac{N}{m}$
work done to stretch the spring 10 cm beyond its natural length ...
$W = \int_0^{0.1} 600x \, dx$
work done to stretch the spring from 20 cm to 30 cm (from 10 cm to 20 cm beyond its natural length) ...
$W = \int_{0.1}^{0.2} 600x \, dx$
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http://www.orcunkoraliseri.com/2017/09/06092017-operative-temperature-mean.html
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### 06.09.2017 - Operative Temperature / Mean Radian Temperature
Figure.Thermometer
# Operative temperature (air temperature + mean radiant temperature + air velocity)
Operative temperature is indictaion of thermal comfort comes from air temperature, mean radiant temperature and air speed. It is helpful to define or predict thermal comfort for occupants of a building. Basically, thermal comfort is related with environmental elements, which are air temperature, air velocity, relative humidity and the consolidation of conditions, also individual properties such as clothing, metabolic heat, acclimatisation, state of health. In many spaces, with low air velocity and where air temperature and mean radiant temperaturemay be similar, air temperature alone can be a reasonable indicator of thermal comfort. However, in spaces where surfaces may be heated or cooled, where there is significant thermal mass, or where solar radiation is present, air and radiant temperatures may be very different and so it is necessary to take account of radiant temperatures in assessing thermal comfort...
Calculation:
Operative temperature = (tr + (ta x √10v)) / (1+√10v)
Where ta = air temperature / tr = mean radiant temperature / v = air speed (m/s)
Or
Operative temperature = (( hr x tr) + (hc x ta )) / ( hr + hc )
Where hc = convective heat transfer coefficient / hr = radiative heat transfer coefficient
Or
Operative temperature = (ta + tr)/2
Where the air speed is less than 0.1m/s, (as is typical in buildings) radiative and convective heat transfers may be similar, and so the equation can be simplified to:
Mean radiant temperature (MRT) is a measure of the average temperature of the surfaces that surround a particular point, with which it will exchange thermal radiation. If the point is exposed to the outside, this may include the sky temperature and solar radiation
Calculation:
Mean radiant temperature could be calculated by globe thermometer. This is a hollow copper sphere painted matt black (to give it a high emissivity) with a temperature sensor at its centre. From the temperature recorded, along with air velocity and air temperature. (needed to account for convective heat exchange)
MRT = globe temperature + 2.42 x air velocity in m/s (globe temperature air temperature)
Or
The mean radiant temperature (MRT) is a means of expressing the influence of surface temperatures on occupant comfort. It can be calculated many ways. In its simplest and least accurate form it is a homogenous steady state area weighted average of the uncontrolled or unconditioned surface temperatures (AUST) written as
Tmr = T1A1 + T2A2 + …+ TNA / ( A1 + A2 + …+ AN )
where,
Tmr = mean radiant temperature, °R
TN = surface temperature of surface N, °R (calculated or measured)
AN = area of surface
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https://www.nature.com/articles/s41467-021-22839-0
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Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.
# Photocatalytic air purification mimicking the self-cleaning process of the atmosphere
### Subjects
Photocatalytic air purification is a promising technology that mimics nature’s photochemical process, but its practical applications are still limited despite considerable research efforts in recent decades. Here, we briefly discuss the progress and challenges associated with this technology.
## Photocatalysis as an eco-friendly method of air cleaning
Air pollution severely endangers human health and the environment and requires highly efficient and viable treatment technologies1. There are various technologies for controlling air pollutants, among which adsorption using activated carbons or highly porous materials is the most commonly practised method. However, the adsorbents need to be frequently replaced, the adsorption efficiency is significantly decreased under humid conditions due to the competing adsorption of water vapor, and the equilibrium adsorption capacity is significantly reduced at low concentrations of air pollutants despite the high surface area of the adsorbents. Other technologies, such as ultraviolet radiation, ionization, and nonthermal plasma decomposition, may generate ozone as a harmful by-product. Thermal-catalytic degradation is effective but energy intensive. Biodegradation usually requires large-scale facilities, and its activity is strongly limited by environmental factors. Considering the above limitations, photocatalytic oxidation (PCO) is proposed as an ideal technology for air purification because it can degrade diverse air pollutants into non-toxic or less harmful forms using solar (or artificial) light under ambient conditions2. The photocatalyst (PC) process (eq 1) has some intrinsic similarity to the self-cleaning mechanism in Earth’s atmosphere (eq 2) in that both are based on indirect (sensitized) photooxidation to generate in situ oxidants (e.g., •OH) in air.
$${\mathrm{PC}}\,({\mathrm{heterogeneous}}\,{\mathrm{sensitizer}}\,{\mathrm{such}}\,{\mathrm{as}}\,{\mathrm{Ti}}{{\mathrm{O}}}_{2})+{{\rm{H}}}_{2}{\rm{O}}(g)+h\nu\,\,{\to }\,\,{\scriptstyle{\bullet}} {\rm{OH}}$$
(1)
$${\rm{O}}_{3}({{\mathrm{molecular}}\,{\mathrm{sensitizer}}})+{{\rm{H}}}_{2}{\rm{O}}(g)+h\nu\to {2}\,{\scriptstyle{\bullet} }{\rm{OH}}+{{\rm{O}}}_{2}$$
(2)
The prominent advantages of photocatalytic air purification are (1) no need for chemicals or external energy input except light, which is not costly when utilizing ambient light or sunlight, (2) safe operation under ambient conditions and relatively humidity-insensitive activity, and (3) the ability to fully mineralize volatile organic compounds (VOCs) to CO2 and H2O. On the other hand, this process suffers from low photon utilization efficiency and slow removal rate, difficulty of scaling up, and fouling/deactivation of photocatalysts during prolonged operation.
## Materials and process characteristics in photocatalysis
The best feature of photocatalysis, which distinguishes it from thermal catalysis, is the need for photons, the flux of which limits the overall process. As a result, many PCO reactions are more limited by the photon flux than by the active surface area, unlike most heterogeneous catalysis methods. Photocatalysts absorb photons to generate pairs of electrons and holes that react with dioxygen, water, and surface hydroxyl groups to generate reactive oxygen species (ROS), such as •OH, O2/HO2•, 1O2, and H2O2, which are the key oxidants that decompose air pollutants. As the majority of electron-hole pairs are rapidly recombined, only a tiny fraction of them (less than 1% in many cases) successfully induce PCO reactions. Much effort has been made to improve the photon utilization efficiency for decades, but the successful performance is still limited. The most studied approach is to extend the photocatalyst’s light absorption edge into the visible light range so that more photons can be used3. Analysis of the research literature (published in 1999–2018) on air-purifying photocatalysts shows that modified TiO2 accounts for the largest share (55.9%), followed by Bi-based materials (11.9%) and WO3 (7.3%), among the studied visible-light photocatalysts2. Regarding modified TiO2 materials with visible light activity, most studies have investigated impurity doping and heterojunctions with narrow-bandgap semiconductors or metal nanoparticles. These methods are also useful for increasing the charge separation efficiency and subsequently generating more ROS. It is interesting to note that TiO2-based photocatalysts are still the most studied and the most practical option for air purification applications despite the strong emphasis on the development of new and novel visible light-active materials in academic research. Although modified TiO2 is generally not a strong absorber of visible light, the strong oxidation potential of the TiO2 valence band (VB) edge, along with its excellent stability, low cost and low toxicity, makes it a practical photocatalyst. As a result, a majority of photocatalytic air purification application studies have employed pure and modified TiO2, which does not seem likely to be replaced by new photocatalytic materials in the near future4,5.
The clear trend in photocatalytic material development research is to search for inexpensive and abundant materials with high visible light activity as an alternative to TiO2 to make the technology more feasible. One popular candidate is carbon-based materials such as g-C3N4 and its derivatives, and various carbon nanomaterials such as reduced graphene oxide, carbon nanotubes, and nanodiamond have also been tested to replace costly noble metal cocatalysts (e.g., Pt, Au, Pd)6,7. However, carbon-based materials suffer from low photoactivity and long-term instability under irradiation due to their tendency to be photooxidized. Although more efficient visible light photocatalyst materials have been extensively tested, the redox power of excited electrons and holes in visible light photocatalysts is lower than that of UV-active photocatalysts. Using less energetic photons results in lower redox power; therefore, it should be noted that visible light photocatalysts are not always the best practical solution for air purification purposes.
Another important issue in developing air-cleaning photocatalytic materials is the durability of the materials, which has been far less considered than the photoactivity in most studies, although it is the most critical factor for practical application. It is commonly observed that photocatalysts are gradually deactivated during photoreactions. This can be caused by the intrinsic instability of the photocatalytic material but more often by catalyst surface fouling as a result of the accumulation of recalcitrant intermediates and products. Such catalyst fouling during air treatment is more serious than in the fouling of aqueous-phase photocatalysis, where water as a solvent dissolves the degradation products and intermediates and prevents their surface accumulation. Photocatalyst surface fouling is most often observed during the degradation of aromatic VOCs and heteroatom-containing (e.g., N, S, and P) VOCs as a result of the accumulation of recalcitrant and non-volatile products5,8. In addition, the real-world application of photocatalytic air cleaning should take into account the presence of nuisance components such as dust and aerosol particles that rapidly foul the photocatalyst surface, which seriously limits the outdoor application of this method. Ensuring the long-term durability of photocatalysts in the real world beyond laboratory conditions presents the greatest challenge in commercializing this technology, which has received little attention thus far. The development of practical photocatalytic air purification systems should require a holistic approach that integrates material design/preparation with diverse compositions, structures, and morphology; reaction condition optimization; reactor design and engineering; and hybridization with other technologies (Fig. 1).
Photocatalytic decomposition reactions of various chemical compounds are highly substrate-specific and strongly depend on the molecular structure and composition of target compounds as well as the kind of photocatalyst8,9. There are a wide variety of air pollutants whose photocatalytic removal efficiencies vary greatly, and an enormous number of published studies have reported the photocatalytic degradation of air pollutants. A Google Scholar search for research articles on “photocatalytic degradation of air pollutants” shows 195,000 results! The main problem in analyzing these published results is that it is very difficult to directly compare photocatalytic activity data that were measured with different methods and experimental conditions. Therefore, there is a strong need to standardize the measurements and assessments to compare the photocatalytic activity data reported from different laboratories. To the best of our knowledge, the current air purification ISO methods are only available for the removal of NO, acetaldehyde, toluene, formaldehyde, and methyl mercaptan, but very few studies follow these standards10. More unified and standardized test methods for photocatalytic air purification have yet to be established.
## Some practical considerations for commercial applications
The design, optimization, and scale-up of photocatalytic reactors are challenging issues for the commercialization of photocatalytic air purification. Optimization of the PCO reactor is more complex than that of typical heterogeneous catalytic reactors, as the PCO process should consider both mass transfer and light delivery parameters. An ideal reactor should allow a sufficient number of photons to reach the full surface area of the photocatalyst to maximize the overall air treatment efficiency. The first essential step in preparing practical photocatalytic reactors is to immobilize a durable and robust photocatalyst layer on the support surface. Photocatalysts can be immobilized by various methods, such as the sol-gel technique, thermal spraying, chemical/physical vapor deposition, and electrophoretic deposition, which is usually followed by high temperature roasting to achieve higher crystallinity and stronger adhesion on the support11. This thermal treatment is technically simple but presents a significant hurdle for the practical fabrication of scaled-up reactors because it demands significant energy consumption and a large furnace or heating facilities, which should increase the overall cost. Therefore, the photocatalyst immobilization process without thermal treatment is highly desirable, but remains challenging. The successful development of an ambient-temperature immobilization process will be a breakthrough in facilitating the commercial applications of photocatalysts for various purposes.
For reactor design, plate and annular reactors are usually used in laboratory studies, but they are not suitable as practical reactors because of their low air throughput and reaction area. Monolith-type reactors with a compact structure have high throughput and a low pressure drop, but the light intensity is rapidly extinguished through the monoliths, hindering the uniform illumination of the catalyst surface. To improve the performance of the reactors, upgraded reactors such as multiplate reactors, multiannular reactors, parallel-channel monolith reactors, and radial-leakage optical fiber honeycomb reactors have been developed12.
## Outlook
Using light to clean up polluted air is an ideal technology that mimics nature’s process and has great potential to be developed as a key technology for air purification, which still needs major breakthroughs in several areas. Although current academic research is heavily focused on materials development, engineering for commercialization demands more investigation of practical issues such as preventing photocatalyst fouling/deactivation, facile and low-temperature immobilization of photocatalysts on a support, and effective and economical reactor design. The extensive search for new and novel materials to replace the classic TiO2 material as an air-cleaning photocatalyst has not been very successful for practical purposes, and it is expected that TiO2-based photocatalysts will remain the mainstay material for the time being. Overall, the most suitable application of photocatalytic air purification seems to be indoor air, where pollutants are at the sub-ppm level and interfering substances such as dust and aerosols can be controlled at a minimal level. The ideal scenario for photocatalytic indoor air cleaning is to utilize ambient room light, which requires the development of more active visible-light-responsive materials. Future research on photocatalytic air purification should address practical issues more seriously to bridge the gap between laboratory findings and real-world problems.
## References
1. 1.
Vandyck, T. et al. Air quality co-benefits for human health and agriculture counterbalance costs to meet Paris Agreement pledges. Nat. Commun. 9, 4939 (2018).
2. 2.
Weon, S., He, F. & Choi, W. Status and challenges in photocatalytic nanotechnology for cleaning air polluted with volatile organic compounds: visible light utilization and catalyst deactivation. Environ. Sci. Nano 6, 3185–3214 (2019).
3. 3.
Verbruggen, S. W. TiO2 photocatalysis for the degradation of pollutants in gas phase: From morphological design to plasmonic enhancement. J. Photochem. Photobiol. C 24, 64–82 (2015).
4. 4.
Weon, S. et al. Active {001} facet exposed TiO2 nanotubes photocatalyst filter for volatile organic compounds removal: from material development to commercial indoor air cleaner application. Environ. Sci. Technol. 52, 9330–9340 (2018).
5. 5.
Weon, S. & Choi, W. TiO2 nanotubes with open channels as deactivation-resistant photocatalyst for the degradation of volatile organic compounds. Environ. Sci. Technol. 50, 2556–2563 (2016).
6. 6.
Li, Y. X. et al. Constructing solid-gas-interfacial fenton reaction over alkalinized-C3N4 photocatalyst to achieve apparent quantum yield of 49% at 420 nm. J. Am. Chem. Soc. 138, 13289–13297 (2016).
7. 7.
Kim, H. I. et al. Robust co-catalytic performance of nanodiamonds loaded on WO3 for the decomposition of volatile organic compounds under visible light. ACS Catal. 6, 8350–8360 (2016).
8. 8.
He, F., Muliane, U., Weon, S. & Choi, W. Substrate-specific mineralization and deactivation behaviors of TiO2 as an air-cleaning photocatalyst. Appl. Catal. B Environ. 275, 119145 (2020).
9. 9.
Ryu, J. & Choi, W. Substrate-specific photocatalytic activities of TiO2 and multiactivity test for water treatment application. Environ. Sci. Technol. 42, 294–300 (2008).
10. 10.
Zhong, L. X. & Haghighat, F. Photocatalytic air cleaners and materials technologies-Abilities and limitations. Build Environ. 91, 191–203 (2015).
11. 11.
Wood, D., Shaw, S., Cawte, T., Shanen, E. & Van Heyst, B. An overview of photocatalyst immobilization methods for air pollution remediation. Chem. Eng. J. 391, 123490 (2020).
12. 12.
Ren, H. J., Koshy, P., Chen, W. F., Qi, S. H. & Sorrell, C. C. Photocatalytic materials and technologies for air purification. J. Hazard. Mater. 325, 340–366 (2017).
13. 13.
Zou, W. X., Gao, B., Ok, Y. S. & Dong, L. Integrated adsorption and photocatalytic degradation of volatile organic compounds (VOCs) using carbon-based nanocomposites: a critical review. Chemosphere 218, 845–859 (2019).
14. 14.
Li, Y. Z., Wu, S. W., Wu, J. C., Hu, Q. Q. & Zhou, C. Y. Photothermocatalysis for efficient abatement of CO and VOCs. J. Mater. Chem. A 8, 8171–8194 (2020).
15. 15.
Mohammadi, P., Ghorbani-Shahna, F., Bahrami, A., Rafati, A. A. & Farhadian, M. Plasma-photocatalytic degradation of gaseous toluene using SrTiO3/rGO as an efficient heterojunction for by-products abatement and synergistic effects. J. Photochem. Photobiol. C 394, 112460 (2020).
## Acknowledgements
This work was supported by the Leading Researcher Program (NRF-2020R1A3B2079953) and Korea Research Fellowship Program (Grant No. 2018H1D3A1A02038503), which were funded by the Korea government (MSIT) through the National Research Foundation of Korea (NRF).
## Author information
Authors
### Contributions
F.H., W.J., and W.C. conceived and wrote the manuscript.
### Corresponding author
Correspondence to Wonyong Choi.
## Ethics declarations
### Competing interests
The authors declare no competing interests.
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
## Rights and permissions
Reprints and Permissions
He, F., Jeon, W. & Choi, W. Photocatalytic air purification mimicking the self-cleaning process of the atmosphere. Nat Commun 12, 2528 (2021). https://doi.org/10.1038/s41467-021-22839-0
• Accepted:
• Published:
• ### Identification of deactivation-resistant origin of In(OH)3 for efficient and durable photodegradation of benzene, toluene and their mixtures
• Kanglu Li
• , Ye He
• , Jieyuan Li
• , Jianping Sheng
• , Yanjuan Sun
• , Jianjun Li
• & Fan Dong
Journal of Hazardous Materials (2021)
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http://mathoverflow.net/questions/126339/generators-for-a-certain-congruence-subgroup-of-sln-z
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# Generators for a certain congruence subgroup of SL(n,Z)
I'm looking for a reference (or quick proof) of the following fact. Fix some $n \geq 3$ and some $\ell \geq 2$. Set $\Gamma_n(\ell) = \text{ker}(\text{SL}_n(\mathbb{Z}) \rightarrow \text{SL}_n(\mathbb{Z}/\ell \mathbb{Z}))$. Next, set
$$\Gamma_n'(\ell) = \{\text{A \in \Gamma_n(\ell) | for all diagonal entries a_{ii} of A, we have \ell^2 | (a_{ii}-1)}\}.$$
It is an easy exercise to show that $\Gamma_n'(\ell)$ is a subgroup of $\Gamma_n(\ell)$. Finally, for all $1 \leq i,j \leq n$ with $i \neq j$, let $e_{ij}$ be the elementary matrix obtained by taking the identity matrix and placing a $1$ at position $(i,j)$.
Observe that $e_{ij}^{\ell} \in \Gamma_n'(\ell)$. The fact I'm interested in is the fact that $\Gamma_n'(\ell)$ is generated by the set of all the $e_{ij}^{\ell}$. I've seen this asserted without proof in print before (though I don't recall exactly where), but I've been unable to work out a proof myself.
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One can probably break up the proof into two steps: show it for $n=3$, and then show that $\Gamma_{n+1}'(\ell)$ is generated by the $n+1$ copies of $\Gamma_n'(\ell)$ sitting inside it in the natural way. I'm not sure how much easier the case $n=3$ is than the general case though (and the statement is false for $n=2$). – Ian Agol Apr 8 '13 at 5:20
There is a Theorem of Tits which says that the group generated by $e_{ij}^l$ has finite index in $SL_n({\mathbb Z})$ if $n\geq 3$. The paper is a Comptes rendus announcement (generating systems of congruence subgroups, CR. ACad. Sci 283 (1976), no. 9 A693-A695 (see the following review http://www.ams.org/mathscinet/search/publdoc.html?amp=&loc=revcit&revcit=244257&vfpref=html&r=16&mx-pid=424966). By a result of Mennicke, finite index subgroups of $SL_n({\mathbb Z})$ are congruence subgroups ($n\geq 3$). So, you need only check that the congruence closure of the group generated by $e_{ij}^l$ in $SL_n({\mathbb Z})$ is of the desired type. This is a purely local checking (prime by prime, for primes dividing $l$) and can be done easily.
ADDED: what you are asking for is (seemingly) stronger than Tits' theorem: not only do the $e_{ij}^l$ generate a finite index subgroup, they generate a specific congruence subgroup. But, as the previous paragraph shows, this is $equivalent$ to the result of Tits.
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I guess the folllowing is a short explicit proof of Tits' result for this very special case, assuming CSP for $\rm{SL}_n(\bf{Z})$ (so this should be seen as a lenghty comment on the above answer). The key step is to show that the group $\Lambda=\langle e_{ij}^\ell\rangle$ contains $\Gamma_n(\ell^2)$: the commutator $[e_{ij}^\ell,e_{km}^\ell]$ is equal to $1+\ell^2( [n_{ij},n_{km}] - n_{ij}^2 - n_{km}^2)+ O(\ell^3)$ where $n_{ab}=e_{ab}-1$ is a nilpotent matrix. On the other hand you have $(e_{ij}^\ell)^\ell=1+\ell^2 n_{ij}$, and as $n_{ij}^2=n_{i,j+1}$ it follows that $\Lambda$ contains in fact also the matrices $1+\ell^2 [n_{ij},n_{km}]$ modulo $\ell^3$. So you finally get that $\Lambda\Gamma_n(\ell^3)$ contains all matrices $1+\ell^2a$ where $a$ is a sum of $n_{ij}$s and their Lie brackets, and these generate the $\bf{Z}/\ell$-module $\mathfrak{sl}_n(\bf{Z}/\ell)$. As remarked by Aakumadula below (and apparently the fact that $\Gamma_n'(\ell)$ contains $\Gamma_n(\ell^2)$ also follows from a theorem of Tits, see her/his answer to this question), it remains to show that for a prime $p$ not dividing $\ell$ the $e_{ij}^\ell$ generate $\Gamma_n$ modulo $\Gamma_n(p)$: in this case we have $\Lambda\Gamma_n(p)=\langle e_{ij}\rangle\Gamma_n(p)$ and it is well-known that the images of the $e_{ij}$ generate $\rm{SL}_n(\bf{F}_p)$. So we have that the congruence closure of $\Lambda$ contains $\Gamma_n(\ell^2)$ and by CSP it follows that $\Lambda\supset\Gamma_n(\ell^2)$.
To conclude: now you have only to show that the $e_{ij}^l$ generate $\Gamma_n'(\ell)$ modulo $\ell^2$. But this is obvious as $\Gamma_n'(\ell)/\Gamma_n(\ell^2)$ is just the subspace of the abelian group $\Gamma_n(\ell)/\Gamma_n(\ell^2)\cong \mathfrak{sl}_n(\bf{Z}/\ell)$ of matrices with zeroes on the diagonal.
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I agree that the key is to show that the group contains $\Gamma_n(\ell^2)$. But I don't understand your argument for this. Can you expand it a bit? Thanks! – Edward Cooper Apr 6 '13 at 2:43
I do not understand Cooper's remark. The theorem of Tits quoted above shows that $e_{ij}^l$ generate a congruence subgroup, which can only be $\Gamma _n(l^2)$. – Venkataramana Apr 6 '13 at 4:08
@Cooper: I edited to give more details. – Jean Raimbault Apr 6 '13 at 12:09
@jean: your argument only proves the local statement that in $SL_n$ of the $l$-adic integers (suppose $l$ is a prime), the $e_{ij}^l$ generate the appropriate congruence closure. It does not prove that at the global level (i.e. the integral points of $SL_n$, ), the $e_{ij}^l$ generate the appropriate congruence subgroup. You do need the theorem of Tits (and that is a non-trivial result). – Venkataramana Apr 6 '13 at 13:44
@Aakumadula: you're right, there is also need to check that at primes $p$ not dividing $\ell$ the $e_{ij}^\ell$ generate all of $\rm{SL}_n(\bf{Z}_p)$. However this can be done in an elementary way since the $e_{ij}$ generate $\rm{SL}_n(\bf{F}_p)$. Edited to add that. – Jean Raimbault Apr 6 '13 at 14:20
FIrst I'd clarify that your notation $e_{ij}^\ell$ actually refers to the matrix with diagonal entries 1, the off-diagonal $(i,j)$ entry equal to $\ell$, and other entries 0.
I don't know what you've read, but since these matrix calculations are quite old and also deeply embedded in the study of the Congruence Subgroup Problem, it's a good idea to look into some of the relevant older literature. On a concrete level, the emphasis is on the group $\Gamma: = \mathrm{SL}_n(\mathbb{Z})$ and its subgroups of finite index, when $n \geq 3$ (the case $n=2$ being much more complicated). Here the key players are the (normal) principal congruence subgroups you've denoted by $\Gamma_n(\ell)$ and the interleaved elementary subgroups: inverse images of finite groups generated by elementary/unipotent matrices.
Key references available online include the 1964 announcement by Bass-Lazard-Serre here and the detailed follow-up by Bass-Milnor-Serre here.
Some of the concrete calculations you are looking for are also written down in section 17 of my (typewritten) 1980 Springer Lecture Notes Arithmetic Groups. The older lecture notes Algebraic K-Theory by Bass (1968) contain a vast amount of detail, and of course there are newer treatises including those by Hahn and O'Meara along with a new book by Weibel.
ADDED: The short paper by Tits cited by Aakumadula is definitely helpful for your question, though it's dependent on the earlier work and is not readily available online (nor is the ancient review I wrote). The literature on congruence subgroups is extensive and often far more general than what you need, but I don't see a direct computational proof of the result you read somewhere. (Advice: Keep track of those sources.) Also, notation varies in the subject, but your choice of $e_{ij}$ is unfortunate since that symbol usually means the matrix with a single nonzero entry $1$. A more usual convention is to write something like $x_{ij}(\ell)$ for your unipotent matrix.
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You my also need to use Lemma 3.1 of arXiv:1301.6082 to deal with the distinction between the subgroup generated by the $e^\ell_{ij}$ and the normal subgroup generated by them, meaning the smallest normal subgroup of the elementary group that contains them. In the congruence subgroup problem one tends to use normal subgroups. – Wilberd van der Kallen Apr 3 '13 at 13:26
As van der Kallen alluded to, Bass-Milnor-Serre (and its antecedents) only proved that the $e_{ij}^{\ell}$ (which, by the way, seems pretty unambiguous to me; it means the $\ell^{\text{th}}$ power of $e_{ij}$) normally generate the whole group $\Gamma_n(\ell)$. This isn't quite what I want, which is a somewhat finer result. – Edward Cooper Apr 3 '13 at 14:39
@Wilberd van der Kallen : Are you sure you got the arXiv identifier right? When I went there, I got a paper entitled "Reaction-diffusion model Monte Carlo simulations on the GPU", which doesn't sound right at all. – Edward Cooper Apr 3 '13 at 14:40
@Edward : Bass-Milnor-Serre and its "antecedents" is not quite right. There s this paper of Tits (which uses Bass-Milnor-Serre) where he proves that the group generated by $e_{ij}^l$ is a finite index subgroup for $n\geq 3$. – Venkataramana Apr 4 '13 at 1:16
@Edward Cooper. Sorry. Try arXiv:1303.60882 by Stepanov. – Wilberd van der Kallen Apr 10 '13 at 6:57
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https://www.lessonplanet.com/teachers/initial-blends-l-blends
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# Initial Blends: L Blends
In this initial blends worksheet, 1st graders say the picture word and listen for its initial blend. Students then write the blends on the lines and read the sentences containing each L-blend word.
Concepts
Resource Details
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http://mathhelpforum.com/advanced-algebra/38310-characteristic-value-vector.html
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# Math Help - Characteristic Value and Vector
1. ## Characteristic Value and Vector
If A is nonsingular, show that the characteristic values of A^-1 are the reciprocals of A, and the A and A^-1 have the same characteristic vectors.
I need help getting started on this. Any help would be greatly appreciated. Thanks,
Jim
2. Fix an eigenvalue $\lambda$ of A and let v be an eigenvector w.r.t. the eigenvalue, write down $Av=\lambda v$. Since A is invertible, $\lambda$ is nonzero and you can multiply both sides of the equation by the inverse of A.
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https://brilliant.org/practice/taylor-series-approximation/
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×
## Taylor Series
The Taylor series is a polynomial of infinite degree used to represent functions like sine, cube roots, and the exponential function. They're how some calculators (and Physicists) make approximations.
# Taylor Series Approximation
Let $$f(x)$$ be a function such that $$f(0)=3, f'(0)=1,$$ and $$f(3)=1.$$ Using a quadratic Taylor polynomial of $$f(x),$$ we can approximate the value of $$f''(0)$$ as $f''(0) \approx -\frac{A}{B},$ where $$A$$ and $$B$$ are coprime integers. Find the value of $$AB.$$
Using the quadratic Taylor polynomial of $$f(x) = \frac{1}{x}$$ at $$x=5,$$ find the approximate value of $$\frac{1}{7}$$ multiplied by $$5^3.$$
For the linear Taylor polynomial $$g(x)=ax+b$$ of $$f(x)=-\frac{1}{x-1}$$ at $$x=2,$$ find the error $$e$$ defined by $e=\int_{2}^{3}{(g(x)-f(x))^2 dx}.$
Using the quadratic Taylor polynomial of $$f(x) = \ln{x}$$ at $$x=4,$$ we can approximate the value of $$\ln{9}$$ in the form $\ln{A}+B,$ where $$A$$ and $$B$$ are rational numbers. Find the value of $$2A^2B.$$
Let $$f(x)$$ be a function such that $$f(0)=1, f'(0)=2,$$ and $$f(3)=1.$$ Using a quadratic Taylor polynomial of $$f(x),$$ we can approximate the value of $$f''(0)$$ as $f''(0) \approx -\frac{A}{B},$ where $$A$$ and $$B$$ are coprime integers. Find the value of $$AB.$$
×
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http://mathhelpforum.com/algebra/90163-need-help-word-problem.html
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# Math Help - Need help on word problem.
1. ## Need help on word problem.
There are 396 persons in a theater. If the ratio of women to men is 2:3, and the ratio of men to children is 1:2, how many men are in the theater?
2. Hi,
Are you sure your numbers are correct? I'm getting 396*6/13 men, which I'm pretty sure isn't physically possible...
If you are having problems with the words, simply get rid of them! Make equations, which are usually much easier to work with. Maths notation is actually quite a modern thing - previously people would do maths in words and sentences, which is hard! For instance, "=" was not introduce until 1557(MacTutor). Also, in some ways maths merely takes away any external noise and gets to the crux of the problem, and what you are dealing with here is quite a good example of this. As sentences, it is hard to solve/understand, but as equations it is less so. Another good example is a thing called Group Theory - essentially it is the abstract study of symmetry, but it has developed into a very powerful tool. Anyway, I'm rambling. However, my point is this - get rid of the words! Make it into something you can deal with.
3. ## Here is my answer.
I think the answer should be this.
women:men =2:3
men:children=1:2
therefore women:men:children=2:3:6
men=396x3/11=108
There are 108 men.
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https://perminc.com/resources/publications/coal-bed-characterization-studies-x-ray-computerized-tomography-ct-micro-ct-techniques/
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## Coal Bed Characterization Studies with X-ray Computerized Tomography (CT) and Micro-CT Techniques
Saites, F., Wang, G., Guo, R., Mannhardt, K. and Kantzas, A.
DOI: 10.2118/2006-027
CIM 2006-027 presented at the 57th Annual Technical Meeting of the Petroleum Society held in Calgary, June 13-15, 2006.
## ABSTRACT
Much of the focus of CBM reservoir assessment in Canada is based on understanding cleats and natural fractures, both in outcrop and in core taken from well bores. Coal characterization studies using imaging devices are presented. X-ray computerized tomography (CT) and micro CT are used on coal samples to provide a better understanding of fracture morphology and apertures. Images are collected in samples of approximately 10 cm in diameter with resolution of (0.4 mm) 2 using X-ray CT, and samples of 1 cm in diameter with resolution of (5_m) 2 using micro CT. Visualization at both resolutions allows for discussion and comparison of structural characteristics at both scales. X-ray CT images are processed to obtain density “logs” and maps under different overburden pressures. The pore space contained helium, and, in one set of scans, argon. Bulk densities increase with increasing overburden pressure. Fracture patterns in both cores were reconstructed from the images using a fracture identification algorithm. Manipulation of the density maps can also provide local strains as a function of increasing overburden pressure.
A full version of this paper is available on OnePetro Online.
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http://link.springer.com/article/10.1140/epjb/e2013-40726-6
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, 86:419
# Investigation of a universal behavior between Néel temperature and staggered magnetization density for a three-dimensional quantum antiferromagnet
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## Abstract
We simulate the three-dimensional quantum Heisenberg model with a spatially anisotropic ladder pattern using the first principles Monte Carlo method. Our motivation is to investigate quantitatively the newly established universal relation T N /√c 3 ∝ ℳ s near the quantum critical point (QCP) associated with dimerization. Here T N , c, and ℳ s are the Néel temperature, the spinwave velocity, and the staggered magnetization density, respectively. For all the physical quantities considered here, such as T N and ℳ s , our Monte Carlo results agree nicely with the corresponding results determined by the series expansion method. In addition, we find it is likely that the effect of a logarithmic correction, which should be present in (3 + 1)-dimensions, to the relation T N /√c 3 ∝ ℳ s near the investigated QCP only sets in significantly in the region with strong spatial anisotropy.
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https://medcraveonline.com/IJVV/who-had-their-finger-on-the-magic-of-life---antoine-bechamp-or-louis-pasteur.html
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Vaccines & Vaccination
Mini Review Volume 2 Issue 5
Who Had Their Finger on the Magic of Life - Antoine Bechamp or Louis Pasteur?
Robert O Young function clickButton(){ var name=document.getElementById('name').value; var descr=document.getElementById('descr').value; var unCopyslNo=document.getElementById('unCopyslNo').value; document.getElementById("mydiv").style.display = "none"; $.ajax({ type:"post", url:"https://medcraveonline.com/captchaCode/server_action", data: { 'name' :name, 'descr' :descr, 'unCopyslNo': unCopyslNo }, cache:false, success: function (html) { //alert('Data Send');$('#msg').html(html); } }); return false; } Verify Captcha × Regret for the inconvenience: we are taking measures to prevent fraudulent form submissions by extractors and page crawlers. Please type the correct Captcha word to see email ID. function refreshPage(){ $("#mydiv").load(location.href + " #mydiv"); }$(document).ready(function () { //Disable cut copy paste $('#msg').bind('cut copy paste', function (e) { e.preventDefault(); }); //Disable mouse right click$("#msg").on("contextmenu",function(e){ return false; }); }); .noselect { -webkit-touch-callout: none; /* iOS Safari */ -webkit-user-select: none; /* Safari */ -khtml-user-select: none; /* Konqueror HTML */ -moz-user-select: none; /* Firefox */ -ms-user-select: none; /* Internet Explorer/Edge */ user-select: none; /* Non-prefixed version, currently supported by Chrome and Opera */ cursor: none; }
Universal Medical Imaging Group, USA
Correspondence: Robert O Young, pH Miracle Inc., 16390 Dia del Sol, Valley Center, California, 92082, USA, Tel 760 751 8321
Received: February 02, 2016 | Published: September 19, 2016
Citation: Young RO (2016) Who Had Their Finger on the Magic of Life - Antoine Bechamp or Louis Pasteur?. Int J Vaccines Vaccin 2(5): 00047. DOI: 10.15406/ijvv.2016.02.00047
The Magic Eraser
There have been several notable occasions in history when persons offering invaluable contributions to the advancement of human understanding have been ignored, ridiculed and even persecuted in their time. In most cases, however, their work has subsequently been given a deserved measure of recognition. Some great ones, though, have not enjoyed such rejuvenation and have “suffered the slings” of obscurity.
So it is with Bechamp’s [1]. Had the profound voice of his science not been silenced, much of humankind may have been spared the worst aspects of the infectious or vital stresses of the 20th century. Since the case can be made that the approved but improper and dangerous treatment of infectious “diseases” over the last century has in large part given rise io the present epidemic wave of degenerative “disease,” including cancer, AIDSyndroine or Ebola, we might have been spared these miseries as well. At the least, we would have understood much more clearly why we have them. Fortunately, however, Bechamp’s [1] work has been kept alive by small, successive bands of truth-seekers.
The adoption by science of Louis Pasteur’s germ theory as the whole truth, without regard to the subtleties and deep insight of Bechamp’s [1] microzymian principle, represents one paraphrased: “There is no medical doctrine as potentially dangerous as a partial truth implemented as whole truth.” Any medical professional, bioscientist, health care practitioner, or lay person for that matter, who wishes to gain insight into the origins and nature of infectious and chronic illness, against the backdrop of a marvelous view of the life process, must consider Bechamp. And they must entertain one of the most important concepts to come out of his illustrious career-microbiological pleomorphism as it relates to disease and its symptoms.
There are four books written about him of which this writer is aware (although there are very likely more) and many works published by him. Of the ones by him, all except one are in the original French. Fortunately, his last book, The Blood and Its Third Anatomical Element, was translated into English in 1911 by Montague [1], M.D., Ph.D., M.A., although it has been difficult to obtain. Of the two major books about him, one is in French and the other [2] is also rare. The other two books about Bechamp [1] are by R.B. Pearson. The Hume [2] book, one Pearson book, and The Blood are once again available as reproductions in the U.S. after a hiatus of several years.
Bechamp [1] considered The Blood his crowning work, and therein he describes an amazing micro anatomical entity and its participation in the clotting process. He also includes details of his work and his experiences with the plagiarisms and “pettifogging ratiocinations” of Louis Pasteur. The French book about him, which author Christopher [3] praised highly to this writer, is by Marie Nonclercq, entitled Bechamp [1], 1816- 1908: L’Homme et le Savant, Originalite et Fecondite de Son Oeuvre. The latter part means, The Man and the Scientist, the Originality and Productivity of His Work. According to Christopher [4], in an account given at a 1991 facts that did not set well with reigning theory, many questions arose... as I read essays and books, of a heretical nature, one could say, written by researchers whose names I never heard mentioned in my classes. Twenty years ago, the World Health Organization proudly declared recently the discovery that the single greatest factor in heart disease is a vitamin E deficiency.
Also perversely awe-inspiring is the fact that a person of Bechamp’s [1] extraordinary accomplishments has been written out of history books, textbooks and all encyclopedias. It is sobering to consider the required degree of authoritarian control over key academic elements in our culture. It is not my intention to belabor the politics, but as the wonders of Bechamp’s work unfold to the mind, the question simply arises, “Why is this not common knowledge?” Yet, we must be grateful that his “erasure” was far from complete.
It is difficult to do full justice to Bechamp [1] without recourse to a book. His work was incessant and prodigious, and his observations prolific. I will attempt to convey some essentials of his biological work-only a part of the picture, as the total output includes chemistry, medicine and pharmacy. He left a remarkable legacy of scientific insight that borders on the spiritual, yet died in relative obscurity with virtually no recognition by peers or the public. Having outlived his wife, his beloved associate Professor Estor, and his four children, he had to endure those hard lessons of life in addition to the one of professional anonymity. However, in keeping with his extraordinary mind, he never lost conviction that the truth would come to light, as would his role in its revelation.
I’m not sure why, when his life touched mine through E. Bechamp is known among a coterie of modern and contemporary admirers, and his work has been followed up, knowingly or not, by perhaps a total of 50 scientists. This group includes such names as Gunther Enderlein; Wilhelm Reich; Royal Raymond Rife; the courageous Australian team of Kalokerinos et al. [5], M.D. (who for many years published information in the Toorak Times, an Australian newspaper); and Naessen [3], including myself, who have brought the Bechampian locomotive to a full head of steam.
It is at once unbelievable and understandable that the superficial dogma of Pasteur [2] could have prevailed over Bechamp’s insights in the 19th century French Academy of Science. Unbelievable because of the meticulous documentation and presentation Bechamp [1] made of his prolific work. Understandable because Pasteur [2] stole enough of the truth to make it pass, while having on his side upper class connections and a doctrine that more suited the cultural (especially religious) moods of the time. Abetting, if not creating, an atmosphere repressive to truth was a mood of impassioned ignorance among ecclesiastic authorities at the University of Lille, where Bechamp [1] had moved in 1875 to teach. In a manner similar to that which devastated Galileo, they vigorously opposed the “heresy” of the microzymian view. Heightening the poignancy of this tragedy was the depth of that ignorance, which was unable to realize that the view was not heretical at all. In fact, Bechamp was a devout Christian who felt his inquiries merely to be revealing the Creator’s modus. But it is perversely awe-inspiring to see such bias having persisted for a century, supported by the structure of authority in bioscience, so that Bechamp’s principles have not yet (2015) been given fair examination in the mainstream.
Things may soon change-for a number of reasons, not the least of which is that research in the medical literature is now burning a raging blaze below the lofty suite in which the few powerful controllers lurk. They will soon have to surrender themselves at the window, or be consumed by the flames. Of course, one way in which they surrender is to rediscover the truth, that is, claim credit for making scientific “discoveries” about matters long ignored or repressed by them and long held as principle in alternative venues. For example, “science” has just discovered that antioxidants are good for asthma, especially vitamins C and E. And after the tireless, definitive work on vitamin E by the Shute brothers probably 20 years ago, the World Health Organization proudly declared recently the discovery that the single greatest factor in heart disease is a vitamin E deficiency.
Also perversely awe-inspiring is the fact that a person of Bechamp’s [1] extraordinary accomplishments has been written out of history books, textbooks and all encyclopedias. It is sobering to consider the required degree of authoritarian control over key academic elements in our culture. It is not my intention to belabor the politics, but as the wonders of Bechamp’s work unfold to the mind, the question simply arises, “Why is this not common knowledge?” Yet, we must be grateful that his “erasure” was far from complete.
It is difficult to do full justice to Bechamp without recourse to a book. His work was incessant and prodigious, and his observations prolific. I will attempt to convey some essentials of his biological work-only a part of the picture, as the total output includes chemistry, medicine and pharmacy. He left a remarkable legacy of scientific insight that borders on the spiritual, yet died in relative obscurity with virtually no recognition by peers or the public. Having outlived his wife, his beloved associate Professor Estor, and his four children, he had to endure those hard lessons of life in addition to the one of professional anonymity. However, in keeping with his extraordinary mind, he never lost conviction that the truth would come to light, as would his role in its revelation.
I’m not sure why, when his life touched mine through Douglas [2] historical biography, such a strong feeling arose in me-the need to “exonerate” him, to bring his name and work to their deserved place of honor in history. Part of it, I’m sure, as with M. Nonclercq, is realizing the health benefits society might reap from understanding him, not to mention the inspiring, if not magical, insight into life and being that his views represent. But I’m still not quite sure why I want to be able to say (if in some way my various expositions about him over the last decade, added to the voices of others who have seen with his eyes, contribute to open re-evaluation of his science), “There, Antoine! Rest in peace, my friend.”
Principles of Micromorphology
While some of the ideas Bechamp addressed predated him, they had not been so clearly described, fully developed, or strongly supported by experimentation. It is said there is nothing new under the sun. If true, it may be because all things, or situations, exist at once in the Creation. It is a matter of perspective, much like looking at a tapestry. Bechamp’s perspective allows us to step back from tight focus and see the loose threads of the germ theory amidst a harmonious and astounding pattern of the life process. He had his “finger” on the magic of life. According to Hume [2], the essence of what he brought to us was as follows: First, he demonstrated that the air is filled with microscopic organisms capable of fermenting any suitable medium on which they happen to land. He showed that the chemical change is carried out by a soluble ferment produced by the organism, and this ferment is analogous to the digestive juices of the stomach. Thus, he identified fermentation as a digestive process. (Young [6] theorizes that all decomposition, even the rusting of steel, is mediated by ferments. It is known, for example that bacteria decompose rock into soil. Microorganisms are at or near the foundation of all life and life processes on Earth. For example, fungal forms are indispensable parts of the roots of most plants, including the largest trees.)
Secondly, the most profound conclusion to which Bechamp’s untiring and painstaking research led him is that there is an independently living micro anatomical element in the cells and fluids of all organisms. This element precedes life at the cellular level, even the genetic level, and is the foundation of all biological organization. What originally piqued Antoine’s procreative curiosity was the discovery, somewhat by accident, that pure chalk from geological deposits at least 11 million years old would liquefy starch and ferment sugar solutions, while man-made chalk would not. After years of work tracking down the cause (fermentation was not understood at the time), he attributed the action to the living remains of organisms long dead. He called this tiny living element a “microzyma,” or small ferment.
Thirdly, he claimed that microzymas routinely become forms normally referred to as bacteria, and that bacteria can revert or devolve to the microzymian state. (This is the principle of pleomorphism, which is central to understanding the appearance of “infectious” and degenerative disease symptoms in the body.)
Fourthly, he explained that atmospheric germs are not fundamental species, but are either microzymas, or their evolutionary forms, set free from their former vegetable or animal habitat by the death of that “medium.”
Bechamp explained: “The microzyma is at the beginning and end of all organization. It is the fundamental anatomical element whereby the cellules, the tissues, the organs, the whole of an organism are constituted.” He referred to microzymas as the builders and destroyers of cells. The quotation emphasizes the constructive aspect of microzymian activity and purpose, but it is the destructive aspect, or the “end of all organization,” which concerns us in disease. He always found microzymas remaining after the complete decomposition of a dead organism, and concluded that they are the only non-transitory biological elements. In addition, they carry out the vital function of decomposition, or they are the precursors of beings (bacteria, yeasts and fungi) which do so. Thus, he clearly presented the idea that the physical life of higher biological forms arises from, is dependent upon, and is recycled by, microscopic beings. Simple, immediate proof of dependence is the indispensable bacterial population in the human GI tract. And it adds piquancy to the whole matter to consider that our digestive and metabolic associates are plants. The crucial “catabolic” aspect of microzymian behavior enters the picture when the body becomes diseased, for, according to Bechamp:
In a state of health, the microzymas act harmoniously and our life is, in every meaning of the word, a regular fermentation. ... In a condition of disease, the microzymas which have become morbid determine in the organism special changes . . . which lead alike to the disorganization of the tissues, to the destruction of the cellules and to their vibrionien evolution during life.
The microzyma is an organized (insoluble) ferment: a living element. Controlled fermentation is a vital physiological process. For example, it is utilized as a means of breaking down toxins in intercellular fluid and the lymphatics. Also, some commercial dietary fiber products contain acacia and slippery elm. These soluble fibers ferment in the gut, resulting in short-chain fatty acids such as butyrate and acetate, which are highly beneficial to the colon wall. Bechamp published a paper (still in French) about the role of microzymas in the production of salivary diastase (ptyalin). Since there are microzymas in every cell, in the blood and intercellular milieu, it is likely that many vital substances, mostly enzymes, are produced by them or by their complexes.
Bechamp said that the process of cellular breakdown is mediated by microzymian fermentation-even in a healthy body. Though there is renewal happening as well, breakdown fermentation (aging) eventually takes over, greatly increasing in intensity upon death. When oxidative metabolism ceases and a body dies, negative surface charges are lost and the terrain goes acid. Microzymas respond to biochemical signals, the most important being pH. The condition of disease is a milieu which presents to the microzymas a premature biochemical signal that the organism is dead. They consequently change their function and evolve into forms capable of more vigorous fermentative breakdown-forms that reflect disease-what Bechamp called “morbidly evolved microzymas.” If the host pays no attention while it is still feasible to adjust, s/he will be recycled sooner than would otherwise be the case.
And Further
"... In disease, it is the elementary tissues or cellules that are affected....
It should result therefrom that tissue and cellular pathology are in reality microzymian pathology. In disease, the cellules have been seen to change, be altered and destroyed, and these facts have been noted. But if the cellule were the vital unit living per se, it would know neither destruction nor death, but only change. If then the cellule can be destroyed and die, while the microzyma can only change, it is because the microzyma is really living per se, and physiologically imperishable, even in its own evolutions, for, physiologically nothing is the prey of death; on the contrary, experience daily proves that everything is the prey of life, that is to say, of what can be nourished and can consume."
Further Conclusions by Bechamp
“That there is produced in the organisms of all living beings, including man, in some part and at a given moment, alcohol, acetic acid, and other compounds that are the natural products of the activity of organized ferments, and that there is no other natural cause of this production than the microzymas of the organism. [Emphasis added. Here is where, in a compromised terrain, the culminate forms where I describe in the main text of my book Sick et al. [7], could play a role. As described by Bechamp-i.e., in an apparently healthy organism-it would likely be the initial development phase.] The presence of alcohol, acetic acid, etc. in tissues reveals one of the causes, independent of the phenomenon of oxidation, of the disappearance of sugar in the organism, and of the disappearance of the gluco-genic matters and that which Dumas called the respiratory foods."
“That, without the concurrence of any outside influence except that of a suitable temperature, fermentation will go on in a part withdrawn from an animal, such as the egg, milk, liver, muscle, etc., or, in the case of plants, in a germinating seed, or in a fruit which ripens when detached from the tree, etc. The fermentable matter that disappears earliest in an organ after death is the glucose, gluco-genic matter or some other of the compounds called carbohydrate, that is to say respiratory food. And the new compounds that appear are the same as produced in the alcoholic, lactic acid and butyric fermentations of the laboratory; or, during life, alcohol, acetic acid, lactic or sarcolactic acid, etc."
“That the microzymas, after or before their evolution into bacteria, attack albuminoid or gelatinous matters only after the destruction of the ... carbohydrates."
“That the microzymas and bacteria, having effected the transformations before mentioned, do not die in a closed apparatus in the absence of oxygen; they go into a state of rest, as does the beer yeast in an environment of the products of the decomposition of the sugar, which products it formed."
“That . . . the necessary destruction of the organic matter of an organism is not left to the chance of causes foreign to that organism, and that when everything else has disappeared, bacteria-and finally the microzymas resulting from their reversion-remain as evidence that there was nothing primarily living except themselves in the perished organism. And these microzymas, which appear to us as the residuum of what lived, still possess some activity of the specific kind that they possessed during the life of the destroyed being.”
Microzymas Unique to Each Organism and Organ
The microzymas were too minute to differentiate with the microscope (even for today’s equipment), and Bechamp knew he was not going to see them in detail. His brilliance shows again, however: “The naturalist will not be able to distinguish them by description, but the chemist and also the physiologist will characterize them by their function.” Having masterful skill in chemistry, he utilized that ability, accompanied by ingenious use of the polarimeter, to draw many of his conclusions. He was led to conclude that an organism’s microzymas are unique to it, and are not interchangeable with those of another. He went further to say that even within a single organism, each organ and tissue has functionally unique microzymas, and that; for example, those of the kidney do not belong in the liver. What, therefore, did he have to say about inoculation?
The most serious, even fatal, disorders may be provoked by the injection of living organisms into the blood; organisms which, existing in the organs proper to them, fulfill necessary and beneficial functions-chemical and physiological-but injected into the blood, into a medium not intended for them, provoke redoubtable manifestations of the gravest morbid phenomena. ". . . Microzymas, morphologically identical, may differ functionally, and those proper to one species cannot be introduced into an animal of another species, or even into another center of activity in the same animal, without serious danger."
How much more foolhardy is it then, when vaccinal microzymas are not only from another species, but are already morbidly evolved and are accompanied by preservatives, formaldehyde, and other chemicals? There is no sanity whatever to this practice. The best that can be said about it is that it may prevent, against the odds, the appearance of varying sets of symptoms. But this is at the price of weakening the immune system, toxifying the body, and possibly setting the stage for degenerative symptoms later in life-all the while doing absolutely nothing for, except perhaps worsening, the underlying disease condition.
As indicated in the above quotation concerning “granulations of the protoplasm,” it would seem that microzymas are also closely related to, and perhaps precursors of, genetic molecules. In an August 8, 1977 address to the (now defunct) International Academy of Preventive Medicine, Drs. Dettman & Kalokerinos [5] had the following to say: "It became increasingly apparent to us that the problems relating to infection and immunization were, to say the least, oversimplified by organized medicine. Perhaps Bechamp was thinking in advance of our modern molecular biologists that refer to genes controlling enzymes! We wondered whether Bechamp’s writing anticipated, in some respects, the discovery of RNA and DNA ? It now appears to us that the experimental data described in Bechamp’s work has, in part, been independently and unknowingly repeated by Professor Bayev of the USSR Academy of Sciences."
In a Personal Communication with Prof. Bayev (1974) Concerning the Common Factors of his and Bechamp’s Work, Bayev States
“Self-restoration of the molecule from its parts was obtained with pure transfer RNA from baker’s yeast. It is a rather simple organic substance of molecular weight 30,00 daltons. Its chemical structure is now identified exactly. I think the microzyma by Bechamp has a more complex chemical nature than a simple organic molecule, but our experiments with transfer RNA molecules prove that self-restoration is possible already at the molecular level” [Emphasis added].
Finally, might we not ask ourselves how much our uncritical acceptance of Pasteur’s work has retarded the development of medical science to this day? In our own work we found that when we became aware of Bechamp’s arguments we were better able to understand some of the puzzles of our findings with Aboriginal infant death in Australia, which initially led us into conflict with the prevailing medical models of disease and immunization. We feel that we have gone too far to turn back, and that we need the help of all health care professionals who dare to think for themselves in working through the tangled web of relationships that govern disease-immunization- nutrition interactions.
Bechamp and Pasteur
Bechamp never denied that the so-called germs of the air or other causes may be contributory, either to decomposition or illness, but only that these have not been expressly created, nor are they needed, for these purposes. As noted, the germs of the air are nothing other than microzymas or their evolved forms from fermentatively destroyed organisms. Their destructive or morbid influence may be added to that already faced by the organism’s endogenous microzymas, which may or may not have initiated morbid evolution. This is a crucial departure from germ theory. That is, without the predisposition of inherent microzymas-which condition is engendered primarily by a faulty internal environment-the germs of the air, or those of other sick bodies, will not produce illness in a person. One can see how this holistic view confers responsibility and power on the individual, as opposed to making him a victim to be saved (by a medical science powerless to do so). In addition to microzymas in the atmosphere, “The spores of the entire microscopic flora may intrude, as well as all the molds that may be born of these spores.”
In the earlier phase of his career, as Professor of Medical Chemistry and Pharmacy at the Faculty of Medicine at Montpellier University, Bechamp and his tireless colleague Professor Estor had many opportunities to test microzymian theory in practice. Examination of an amputated arm and many examinations of frozen plants during a particularly cold winter convinced them that upon injury, bacteria developed internally without any outside influence. Bruising an apple without breaking the skin is an example; the broken cells will autoferment. This is one basis for the surgical cleaning of wounds.
Pasteur [2], on the other hand, a non-physician and proponent of the germ theory, seems to have lacked a certain understanding of living systems. He considered the body to be a collection of inert chemicals, and therefore after death he expected nothing living in it. When life would inevitably appear in dead organisms, he had to draw the conclusion that it resulted from invasion from without by the beings whose existence had been taught to him and the world by Bechamp. Either he saw but would not admit, or he simply could not fathom, that microorganisms are already inherent to humans and every other organized medium on the planet, all of which contain, are composed of, and have developed from, microzymas. Unfortunately, the persuasiveness of Pasteur’s superficial conclusions held sway over the deeper, rather elusive, complex, profound, even mystical workings of life and pathology.
Bechamp
Long before Davaine considered the inside of the organism to be a medium for the development of inoculated bacteria, Raspail said, “The organism does not engender disease: it receives it from without... Disease is an effect of which the active cause is external to the organism.” In spite of this, the great physicians affirm, in Pidoux’ happy words, “Disease is born of us and in us.”
But M. Pasteur, following Raspail... maintains that physicians are in error: the active cause for our maladies resides in disease-germs created at the origin of all things, which, having gained an invisible entry into us, there develops into parasites. Form Pasteur [2], as for Raspail, there is no spontaneous disease; without microbes there would be no sickness, no matter what we do, despite our imprudences, miseries or vices! The system, neither new nor original, is ingenious, very simple in its subtlety, and, in consequence, easy to understand and to propagate. The most illiterate of human beings to whom one has shown the connection between the acarus and the itch understands that the itch is the disease of the acarus. Thus it comes about that it has seduced many people who give unthinking triumph to it. Above all, men of the world are carried away by a specious, easy doctrine, all the more applicable to generalities and vague explanations in that it is badly based upon proved and tried scientific demonstrations.
Much of Pasteur’s refusal to accept microzymian theory may have arisen from pure rivalry which came into focus when Bechamp solved, right under the Pasteur’s nose, a disease crisis threatening the French silkworm industry. Since the two must have known each other previously, we must be open-minded enough to allow that Bechamp, though concerned for his country’s important industry, may have indulged himself in a little one- up man ship in his embarrassment of Pasteur, who gained more privilege from social connection than from earned merit (thus, in most books, Pasteur is given credit for solving the crisis). If so, it may have cost Bechamp dearly, because it earned him the eternal resentment of the volatile chemist, who took every future opportunity to oppose his tormentor. And it was primarily the “specious easiness” of germ theory that allowed Pasteur to get away with it, because few scientists of the time were sufficiently skilled to probe deeply enough beneath the superficialities. Few possessed enough knowledge or insight to understand the elusive complexities. And Bechamp warned against facile judgments when he wrote in 1869:
"In typhoid fever, in gangrene, in anthrax, the existence has been proved of bacteria in tissue and in the blood, and one was very much disposed to take them for granted as cases of ordinary parasitism. It is evident, after what we have said, that instead of maintaining that the affection has had as its origin and cause the introduction into the organism of foreign germs with their consequent action, one should affirm that it only has to do with an alteration of the function of the microzymas, an alteration indicated by the change that has taken place in their form."
Again
"An egg contains nothing organized except microzymas; everything in the egg, from the chemical point of view, will be necessary for the work of the microzymas; if in this egg its ordered procedure should be disturbed by a violent shaking, what happens? The albuminoid substances and the bodies of fat remain unchanged, the sugar and the glycogen disappear, and in their place are found alcohol, acetic acid and butyric acid; a perfectly characterized fermentation has taken place there. That is the work of the microzymas, the minute ferments, which are the agents and the cause of all observed phenomena. And when the bird’s egg has accomplished its function, which is to produce a bird, have the microzymas disappeared? No, they may be traced in all the histological elements; they pre-exist-one finds them again during the functioning and the life of the elements; one will find them yet again after death; it is by them that the tissues are made alive."
"The part of organized beings essentially active and living, according to the physiologists, is the granular protoplasm. We went a step farther and said it is the granulations of the protoplasm, and though for their perception a sort of spiritual insight is required, we have based our conclusions upon experimental proofs of the most varied and positive nature. Bichat looked upon the tissues as the elements of the bodies of higher animals. With the help of the microscope, very definite particles, cells, were discovered, and were regarded in their turn as elementary parts, as the last term of the analysis. . . . We have said in our turn: The cell is an aggregate of a number of minute beings having an independent life, a separate natural history. Of this natural history we have made a complete description."
Bechamp apparently had a good sense of place in the scientific pursuit (“in our turn”) of the ever-retreating Ultimate Secret. He realized that the truth of empiricism is for the time, or is in the process of evolving. No doubt he would willingly have given up microzymian theory in face of right evidence of a newer observation. I am presenting science with a newer, though highly correlative, observation. For, as Bechamp attributed all fermentation in the body to microzymas, we now are able to see that it is also carried out by higher evolutionary forms-yeast and fungus. He would have been open to the idea that bacteria also evolve, and that there may even be a step or two between microzymas and bacteria, e.g., viruses. However, as I have suggested, functionally the virus form is very likely something other than what it is thought to be in the mist-ified Pasteurian version of bioscience.
In this article the distinction has repeatedly been made between the disease condition and its symptoms. This idea is inherent in microzymian principle, and it is interesting that Bechamp alludes to the source of the disease condition as “imprudences, miseries or vices.” This is a close approximation in different terms of the holistic gamut of precursors to physiological ill-being: improper diet, emotional upheaval and various selfdestructive behaviors. Yet it is a testimony to the power and skill of the propagandists of mainstream medicine and the Pasteurian decalogue itself that serious illness remains such a mystery in the mind of the masses.
Cosmic Microzymas
It is also interesting to hear the scientist speak of “spiritual insight.” And it is interesting as well to consider microzymas in terms of Eastern modes of spiritual thought, such as yoga, in which it is felt that our creation is an ongoing process. That is, life was not put here and simply proceeds, but it, and we, are coming into being in the moment. Thus, there is constant “turnover,” or renewal and healing. In this scenario, the microzyma may be seen as an early, if not the primary, transmutation from the fine vibrations of the Cosmic Life Force into a denser form or pattern of life-something not explainable by biochemistry, certainly. Due to the colloidal nature of these nascent elements, they carry high levels of energy and may also be receptive to frequencies of light and radiation asactivating or informational signals. During formation, or once formed, they may be stimulated by cosmic energy, which comes directly into our being, which provides energy that cannot be accounted for in the Krebs cycle, which is ionizing, and which has been interpreted as carrying part of the holographic human archetypal information. Is the microzyma Colloidal Intelligence, or a modus of the Creative Intelligence-a living transducer for the Idea in Consciousness, which it translates into the cellular anatomy? It was said earlier that microzymas respond to the pH of the surrounding medium, reforming when appropriate. However, the chemical aspect may be just an obvious way for us to qualify the situation. Perhaps the change in pH alters vibrations or resonant frequencies, changing the microzymian quality of reception, transmittal or transduction of the Life Force and cosmic rays.
Bechamp said the microzyma is imperishable. Canadian microscopist Gaston Naessens says his analogous somatid particles have survived carbonizing temperatures, 50,000 rems of radiation, and all acids. If these claims are true, could such imperishability stem from being at the interface of energy/matter and Consciousness, i.e., from the imperishability and constant materialization of life itself? It may therefore be that only the Mystery of life stands prior to the microzymian patterns.
Elaborate Colonies
An interesting corollary to microzymian principle is the idea presented by Margulis et al. [8] in their book Micro-Cosmos-that all higher forms of life are elaborate colonies of microforms that have undergone a natural assimilation into the more complex whole, thus becoming cells or cooperative parts of cells. Some forms have not, or not yet, become assimilated into tissue, and so appear as separate symbionts. The intestinal bacteria are an excellent example. Based on this theory, an entertaining conjecture is that since the primordial, colonizing forms are plant life, animals don’t exist per se, so that humans are complex, mobile, talking vegetation.
Unfortunately, Micro-Cosmos lacks the insight microzymian principle might bring to it. It fails to recognize life prior to the cell, and therefore cannot consider what may be the primary orchestrative tools of the colonization process. It discusses DNA repair enzymes with no suggestion as to their origin.
This article also does not take into account the rapid functional changes of microforms in response to terrain imbalance, and is mystified by cancer: “It is as if the uneasy alliances of the symbiotic partnerships that maintain the cells disintegrate. The symbionts fall out of line, once again asserting their independent tendencies. . . . The reasons, of course, are not all that clear, but cancer seems more an untimely regression than a disease." Here is what seems a struggle with the bonds of the Pasteurian decalogue. The symbionts falling out of line might easily have been expressed, “The microzymas change their function."
Confirmation of Bechamp
There have been many modern and contemporary confirmations of various aspects of Bechamp’s work. One of the earliest and most piquant was reported in an article in The Times, a London newspaper, on April 8, 1914. A French bacteriologist, Mme. Henri, had succeeded in transforming an anthrax bacillus into a coccus form having entirely different functional properties. It could easily have been explained by Professor Bechamp, who sat virtually unrecognized at the London Medical Congress in 1881, where plagiarist Pasteur appeared amidst outbursts of cheering as his country’s representative, and where, as reported in The Times, August 8, 1881, he categorically denied the pleomorphism of B. anthracis.
Pasteur also jumped to the conclusion that each kind of germ produces one specific fermentation, while Bechamp proved that a microorganism might vary its fermentation effect in conformity with the surrounding medium. Bechamp’s assertion that these microforms, under varying conditions, might even change their shape was proved conclusively by F. Loehnis and N.R. Smith of the U.S. Department of Agriculture in 1916 (Journal of Agricultural Research, July 31,1919, p. 675).
And, for evidence that the biological terrain is the determinant factor over the mere presence of a symptogenic microform, we may return to
Kalokerinos et al. [5]: It should come as no surprise to discover that almost every pathogen may be isolated from the majority of so-called “healthy” people: Candida is such an example, and here we quote from the Manual of Clinical Mycology (Conant, Smith, Baker & Calloway, 1971): “Since pathogenic strains of C. albicans can be isolated from (1) normal skin, (2) normal oral and vaginal mucous membranes and (3) stools of normal individuals, it is obvious that most infections have an endogenous source, and the determination of the source of the infection is as difficult as it is with Staphylococcus aureus infections.
This revelation also highlights a recent example of the false conclusions to which one is led by germ theory: The news in research on atherosclerosis is that scientists have isolated a chlamydia-type organism in the plaque, and have concluded that it is the cause of this symptom. The plan is to use antibiotics to combat this “pathogen.” There is only one guarantee in this folly: at the very best they may achieve atherosclerosis without the chlamydia. At worst, they will exacerbate the mounting crisis in health caused by a half-century of antibiotic abuse.
Perhaps the most profound confirmation of pleomorphism was executed by another nearly obliterated genius, this time an American microscopist with the alliterative name of Royal Raymond Rife. His story was told in an impressive piece of work called “The Rife Report” by investigative reporter Lynes [9]. It has been published in book form as The Cancer Cure That Worked!, which is highly recommended from several standpoints-for its revelations about Rife’s research and technology, which would be astounding for these times, never mind for the late 1920s to mid-30s; for a wonderful background on many pioneering figures in biology; for anyone interested in a deeper understanding of where medicine has gone in the United States; and not least, for a wonderful Foreword by John W. Mattingly of Colorado State University, whose writing has always been an inspiration whenever encountered.
Rife’s extraordinary microscope (with 31,000 diameters resolution), reported on in great detail in the Feb. 1944 Journal of the Franklin Institute (Vol. 237, No. 2), was capable of detail and clarity surpassing the newly emerging electron microscopes. Its use of prismatically dispersed natural light frequencies, rather than electron beams and acid stains, allowed clear views of living subjects. Weighing 200 pounds, standing 2 feet high, and consisting of 5,682 (!) parts, the Rife Universal Microscope was an unsung wonder of the world, and the world has thus far been robbed of this absolutely elegant design.
In 1920 Rife began doing research in the electronic treatment of “disease,” specifically to find a way to destroy the tubercle bacillus by means of radio frequency (r.f.) radiation. Attempts to do so were trial and error because the organism’s resonant frequency was unknown. Lynes [9] tells us that when the frequency was finally found and the bacteria killed, the subjects (poor guinea pigs!) died of toxicity. Rife reasoned that there was a viral form in the bacteria that survived the beam because it had a different frequency. But the virus was beyond the reach of his current microscope, which relied on chemical stains. Through an intuitive flash, he “conceived first the idea and then the method of staining the virus with light.'’’’ The idea was based on the principle of resonant frequency. Each microorganism has its own fundamental frequency of light, something Bechainp apparently took advantage of with his polarimeter. Rife arrived at the conclusion that light could be used, instead of fatal chemicals, to “stain” the subject. This was brilliant. Equally brilliant was its execution. A brief, partial description of the instrument, taken from the Journal’s review, is irresistible.
The entire optical system-lenses and prisms, as well as the illuminating units-are made of block-crystal quartz. The illuminating unit used for examining the filterable forms of disease organisms contains fourteen lenses and prisms, three of which are in the high-intensity incandescent lamp, four in the Risley prism, and seven in the achromatic condenser, which incidentally has an aperture of 1.40. Between the source of light and the specimen are subtended two circular, wedge-shaped, block-crystal quartz prisms for the purpose of polarizing the light passing through the specimen, polarization being the practical application of the theory that light waves vibrate in all planes perpendicular to the direction in which they are propagated. When light comes into contact with a polarizing prism, it is split into two beams, one of which is refracted to such an extent that it is reflected to the side of the prism, without, of course, passing through the prism, while the second ray, bent considerably less, is enabled to pass through the prism to illuminate the specimen. When the quartz prisms on the Universal Microscope, which may be rotated with vernier control through 360 degrees, are rotated in opposite directions, they serve to bend the transmitted beams at variable angles of incidence while, at the same time, since only a part of a band of color is visible at one time, a small portion of the spectrum is projected up into the axis of the microscope. It is possible to proceed this way from one end of the spectrum to the other-infra-red to ultra-violet. Now, when that portion of the spectrum is reached in which both the organism and the color band vibrate in exact accord with one another, a definite, characteristic wavelength is emitted by the organism. In the case of the filterpassing form of the Bacillus typhosus, for instance, a blue light is emitted, and the plane of polarization is deviated plus 4.8 degrees. ... A monochromatic beam of light corresponding exactly to the frequency of the organism is then sent up through the specimen and the direct, transmitted light, enabling the observer to view the organism stained in its true chemical color and revealing its own structure in a field which is brilliant with light.
Recall that Bechamp said the chemist would identify microzymas by their function. Their evolved forms would also have a chemical function, or in this case, a signature. Thus, we evolved scientifically from analysis based on light polarizations to that based on the emission of light frequencies, which Rife referred to as the organism’s “true chemical refractive index.”
The Journal then explains that instead of light rays from the specimen passing through the objective and converging, they pass through a series of special prisms which keep the rays parallel:
It is this principle of parallel rays in the Universal Microscope, and the shortening of projection distance between the prisms, plus the fact that three matched pairs of ten-millimeter, seven-millimeter and four-millimeter objectives in short mounts are substituted for oculars, which make possible not only the unusually high magnification and resolution, but which serve to eliminate all distortion as well as all chromatic and spherical aberration....The coarse adjustment, a block thread screw with forty threads to the inch, slides in a one and one-half inch dovetail which gibs directly onto the pillar post. The weight of the quadruple nosepiece and the objective system is taken care of by the intermediate adjustment at the top of the body tube. The stage, in conjunction with a hydraulic lift, acts as a lever in operating the fine adjustment. A six-gauge screw having a hundred threads to the inch is worked through a gland into a hollow glycerine-filled post, the glycerine being displaced and replaced as the screw is turned, allowing a five to one ratio on the lead screw. This, accordingly, assures complete absence of drag and inertia. The fine adjustment being seven hundred times more sensitive than that of ordinary microscopes, the length of time required to focus ranges up to one hour and a half.
A major upshot of Rife’s work was his ability, through several pleomorphic stages, to transform a virus he found in cancer tissue into a fungus, plant the fungus in an asparagus- based medium, and produce a bacillus E. coli, the type of microform indigenous to the human intestine. This was repeated hundreds of times. By this accomplishment, Rife showed that the pleomorphic capacity of microforms goes beyond the bacterial level to the fungal level. Dr. Young [6] has observed this cycle, and is suggesting that its progression to the last stage-mold-is critical. And he includes in this cycle the very important stages intermediate to microzymas and bacteria, the protein complexes usually referred to as viruses, and their immediate descendants, the cell-wall deficient forms detailed by Lida Mattman, Ph.D.
What’s more, Rife identified 10 families in the whole spectrum of microlife. Within each family, any form/member could become any other. Also, the fact that organisms have resonant frequencies allowed Rife to further develop his r.f. “beam ray,” which helped rid the body of cancer symptoms.
Apparently, Rife was not aware of Bechamp. Had he been (he was about 20 years old when Bechamp died on the other side of the Atlantic), a light of another frequency might have been thrown on his research, what a marvelous and beneficial revelations might have arisen with Rife's technology guided by Bechamp's vision? However, even though saddled i the beginning with a germ-theory mindset, he managed to rise above its worst effects. Demonstrating an instinctive understanding of the disease process, Rife made the following statement: “We do not wish at this time to claim that we have cured cancer, or any disease, for that matter. But we can say that these waves, or this ray, as the frequencies might be called, have been shown to possess the power of devitalizing disease organisms, or 'killing' them when tuned to an exact wavelength, or frequency, for each different organism." And again: "In reality, it is not the bacteria themselves that produce the disease, but the chemical constituents of these microorganisms enacting upon the unbalanced cell metabolism of the human body that in actuality produce the disease. We also believe if the metabolism . . . is perfectly balance or poised, it is susceptible to no disease."
While he was making the classic error (perhaps a semantic one) of referring to symptoms as the disease, he seemed aware that disease-associated microorganisms do not originally produce the condition which has supported their morbid evolution in the animal or human body. This fine, but critical, distinction is missing in the views of all the researchers reported on in Lynes [9] book. Even as they stood opposed to the orthodoxy, they still pursed these morbidly evolved symptoms with the intent of curing the visible or diagnosed "disease."
When Rife first destroyed the tubercle bacillus, the guinea pigs died of toxic poisoning. Could that poison have been bacterial debris, including endotoxin, and the death a severe Herxheimer reaction? Rife went on to search for a virus he assumed was released when the bacteria died, but if he had understood what Bechamp explained and what I am emphasizing now, he would have known that the organism’s microzymas were thus set free in the medium. And we can now understand that there was no virus per se, but only variously complexed microzymas.
As a poignant insight into the passion of a man of brilliance whose revelations were denied to the world by avarice, Lynes presents a report given in 1958 by one of Rife’s coworkers, who had known him from the early days of his career:
“He finally got to a point where from years of isolation and clarification and purification of these filterable forms, he could produce cancer in the guinea pigs in two weeks. He tried it on rats, guinea pigs and rabbits, but he found finally that he could confine his efforts to guinea pigs and white rats, because every doggone one was his pet. And he performed on them . . . the most meticulous operations you ever want to see in all your born days. No doctor could ever come near to it.
“He had to wear a big powerful magnifying glass. He performed the most wonderful operations you ever saw. Completely eradicating every tentacle out from the intestines, and sewed the thing up and it got well and didn’t know anything about it at all. Did it not once but hundreds of times. This is a thing that again and again I wish was published. I wish with all my heart that all the detailed information that he developed could be published because the man deserves it."
“He finally got these cultures on the slide. He could look through this thing and you could see them swimming around absolutely motile and active."
Then he’d say, ‘Watch that.’ He’d go turn on the frequency lamps. When it got to a certain frequency, he’d release the whole doggone flood of power into the room. The doggone little things would die instantly.'
“He built the microscopes himself. He built the micro-manipulator himself. And the micro-dissector and a lot of other stuff."
“I’ve seen Roy sit in that doggone seat without moving, watching the changes in the frequency, watching when the time would come when the virus in the slide would be destroyed. Twenty-four hours was nothing for him. Forty-eight hours. He had done it many times. Sat there without moving. He wouldn’t touch anything except a little water. His nerves were just like cold steel. He never moved. His hands never quivered.
“Of course he would train beforehand and go through a very careful workout afterward to build himself up again. But that is what I would call one of the most magnificent sights of human control and endurance I’d ever seen.
“I’ve seen the cancer virus. I have seen the polio virus. I’ve seen the TB virus. Here was a man showing people, showing doctors, these viruses of many different kinds of diseases, especially those three deadly ones-TB, polio and cancer.
"Time and time again since that time some of these medical men have made the proud discovery that they had isolated we will say one of the viruses of cancer, had isolated one of the viruses of polio. Why, that was one of the most ridiculous things in the world. Thirty-five years ago Roy Rife showed them these things.
“These machines demonstrate that you could cure cancer- all crazy notions of usurping the rights of the AMA notwithstanding. They definitely could take a leaf out of Roy Rife’s book and do an awful lot of good to this world for sickness and disease. As a consequence, we have lost millions of people that could have been healed by Rife’s machines."
"I like Roy Rife. I’ll always remember Roy as my Ideal. He had a tremendous capacity for knowledge and a tremendous capacity for remembering what he had learned. He definitely was my Ideal. Outside of old Teddy Roosevelt, I don’t know of any man any smarter than him and I’ll bank him up against a hundred doctors because he did know his stuff with his scientific knowledge in so many lines. He had so many wrinkles that he could have cashed in and made millions out of it if he had wanted to and I do mean millions of dollars. Which would have benefited the human race, irrespective of this tremendous thing that he built which we call the Rife ray machine."
“In my estimation Roy was one of the most gentle, genteel, self-effacing, moral men I ever met. Not once in all the years I was going over there to the lab, and that was approximately 30 years, did I ever hear him say one word out of place."
"All the doctors used to beat a path to Rife’s lab door and that was a beautiful lab at one time. It was beautifully arranged inside. The equipment was just exactly right; his study was just wonderful. It was a place of relics and the atmosphere could not be duplicated anywhere.” (It is noteworthy that even though Rife entered the realm of vivisection, he at least showed the compassion to fix the damaged animals.)
More Cosmic Tones
For some time there have been “Rife instruments” on the market, using his frequencies in an electrode-pad configuration, and sold for research purposes. But that r.f. beam ray, that was the “magic,” technologically speaking, at least. And now an instrument has appeared claiming to be a re-creation of the original (see “Revival and Caution” below). Rife would probably have been the first to question whether the beam deals with the underlying disease condition. In this respect, I would like to suggest a consideration of the beam in terms of both the microzyma and the yogic principle of the chakras.
In yoga, the chakras (“wheels” or vortices of energy) are said to be the “organs” of the subtle body (the energy blueprint of the being). They are tuned to light frequencies corresponding to the colors of the rainbow. One’s personality, physical and physiological qualities, and even the health of the individual are said to arise from their infinitely complex configurations and their interactions with other fields. They are also spiral vortices through which the meridians of acupuncture flow. By way of the neurolymphatic reflexes and neurovascular points of the body, these flowing energies are intimate with the systems, organs, cells and chemistry of the physiology.
In terms of what was suggested earlier about the cosmic microzyma, consider what Christopher [10], yogi and physicist, has written: "... (It is) very likely that the chromosome, when exerting its biochemical effects in replication is NOT an indivisible unit with all its many constituents, in a precise, unchanging hereditary chemical pattern existing from one generation to the next. It is, of course, subject to evolutionary CHANGE. Yet in their function, these chromosomes have to be capable of precise replication, so they must spontaneously aggregate into patterns of LIFE (consciousness of form), which is characterized by the chemical environment in the nucleus of the cell. Any change in this immediate environment, such as a change in the specific frequency of a sharply selected energy, of radiation, of light, of electromagnetic waves or of sound, may alter not only the structural relationship of the molecules in the cell nucleus, but also their biochemical and genetic activity."
(Taken from pp. 813-814 of Nuclear Evolution, a work on the physics of Consciousness published in 1977, almost one century after Bechamp created the name “microzyma.”)
"Consequently, what if the Rife beam, in addition to its resonant effect on microforms, was influencing the frequency balance of the chakras or the balance and freedom of flow in the meridians, perhaps doing what might be called R.F. Acupuncture, and perhaps ultimately “tuning” the microzymas? This might constitute a sufficient rebalancing of the being, or an altering of its vibrational condition, to be considered curative; and it might be maintained if the individual were subsequently to nurture their psychobiological terrain, which includes “the chemical environment in the nucleus of the cell.”
What more could the scientific world have been waiting for than what Rife showed it? Significantly, he was not working in a vacuum but had the attention and support of respected biomedical scientists and doctors, including Dr. Edward C. Rosenow of the Mayo Clinic; Dr. Arthur I. Kendall, Director of Medical Research at Northwestern U. Medical School; and Dr. Milbank Johnson, member of the board of directors at Pasadena Hospital in California. As Lynes informs us, newspapers reported on Rife’s work, including significant clinical success. And as noted, no less a prestigious organization than the Franklin Institute did a detailed report on him. But, not only did the medical establishment (AMA) turn its back on Rife and his safe, effective means of eradicating cancer symptoms, but it systematically conspired to destroy him-which it did not once, but twice. Thus, Bechamp and then his unwitting supporter, Rife, geniuses of the caliber of Copernicus, Galileo and Lavoisier, were rubbed into obscurity. (While on this note, we might remember another genius pleomorphist, Wilhelm Reich, who died miserably in an American prison for attempting to bring truth to light.)
It didn’t take much to see that if Pasteur’s noxious poisons could garner even a semblance of success, the monetary potential would be stupendous. Thus, his greatest claim to fame ought to have been the inauguration of the “calamitous prostitution of science and medicine to commercialism” [2]. Research facilities modeled after the one opened in 1888 in Paris, and used for brutal experimentation on living animals, as well as the production and sale of vaccine drawn from sickened bodies, came into existence all over the world. Bechamp’s brilliant expositions took second place to the dawning of a “new” era. It was the era of stone-hearted torture of fellow creatures and cruelty to our own species. It was the era in which bacterial disease symptoms were supplanted over time with a second wave of modern chronic fungal “infection.” Surfing this wave of degenerative mycotic infestation-officially unacknowledged as such-partially comprising heart disease, cancer, diabetes, so-called autoimmune disease and AIDSyndrome, were the profiteers, supported by arrogant, single-minded adherence to
a scientifically and philosophically flawed, superficially plausible, and financially exploitable model of life and health.
Lynes [9] tells us that Rife found himself in the path of Morris Fishbein, the Hitlerian ruler who headed the AMA from the mid-1920s until 1949, when he was forced from his position by a revolt among doctors. In Chicago, Fishbein had gotten wind of a clinic in San Diego using Rife’s beam-ray method of eliminating cancer symptoms. When refused a buy-in, he used his influence to bring the manufacturing company down in court for operating without a license. This blow to medicine in the late 1930s was a major step in suppressing the knowledge of pleomorphism, the mind-boggling Rife Universal Microscope, and the amazing radio frequency beam instrument used in the clinical setting.
In the second wave of suppression, the establishment (FDA) “Elliot-Nessed” a factory established in the 1950s by Rife and associate John Crane to manufacture the beam ray instrument. Everything was destroyed, records confiscated, and every practitioner possessing a unit was pursued and forced to surrender it as illegal.
Many other courageous individuals have been a part of the process of bringing the hidden truth about microorganisms and their symptogenic properties to light. One of the most significant is Dr. Virginia Livingston-Wheeler. Though she is discussed in the main text, she deserves another mention as a key figure who also faced suppression-the stress of being made invisible-by the sciomeds (power structure of scientific medicine). She published a book in 1983, The Conquest of Cancer, and, according to Lynes, wrote many articles and made presentations to science societies, including the New York Academy of Science, and international conferences. Lynes reports that she once returned from a presentation at an international symposium in Rome to find that her research funds with a major hospital had been canceled and the laboratory closed. During the four or five decades following the first establishment backlash at Rife, several other scientists, including Dr. Eleanor Alexander-Jackson, Dr. Irene Cory Diller, and Lida Mattman, Ph.D. (cell-wall deficient forms), stood in the face of intimidation to continue the valiant, yet feeble, tradition of unbiased biomedical science.
Revival and Caution
There is now afoot, as recently shown on the television show “Strange Universe” (March, 1997), a movement to revive the Rife beam-tube technology. Equipment was shown, as were moving pictures of the lysis of several unidentified microorganisms implied to be culprits in disease. Testimonies were given by a few people saying that they, or people they knew, have been helped by this beam ray. While this is an interesting and promising development, a note of caution is very much in order, so that folks do not end up like Rife’s guinea pigs, being put to death by a violent Herxheimer reaction. I believe the approach I recommended by is safer-more holistic and harmonically based in that we make the environment dissatisfactory to these symptoms of disease, so that instead of exploding on the spot and spewing poisons, they simply “pack their bags and leave.” That is, they will, of themselves, devolve into stages of the pleomorphic cycle consistent with the frequencies natural to a harmonious terrain; or will become so devitalized that the immune system can easily trash them.
It is hoped that this overview has given a provocative taste of what lies obscured in the history of biology. The reader is encouraged to explore the Hume & Lynes [2,9] books especially, as well as that of the beacon of 19th-century bioscience, Bechamp [1]: The Blood and Its Third Anatomical Element.
A Note of Emphasis
In this writer’s opinion, it is a poverty of compassion, the utmost arrogance, faultiness of perspective, and an error of science to inflict self-generated human miseries on innocent animal species in research laboratory experiments. Each year some 100 million animals are killed. Though many such experiments are used as references in this book, this is not a sanction. It is done to show the kind of results being ignored by “authorities” who believe in these methods, to accommodate professionals who live by them, to appease reductionist minds, and to suggest that enough is enough. Human development and quality of life are unlikely to improve in any way by this torture of fellow creatures, unless such change occurs in the heart to make such practice unthinkable. The benefit to science and society is highly speculative and frequently negative. Let the experiments be done on human volunteers, whose physiology at least lends some logic to the process. Thalidomide was animal tested. Aspirin will kill a cat. Sheep can eat arsenic.
The habitual basis for vivisection is not founded in true science, but in profound alienation from nature and detachment from the nature of being. It continues out of species prejudice and an egocentric machismo that feeds on conquering nature via destructive analysis. It continues out of a merry-go-round intent to keep laboratories busy, researchers working, and to keep the research supply industry rolling in money. And it continues out of the habitual ignore-ance of the principles of wellness, which have long been in place in many forms. The fault for our rampant “diseases” may be ascribed to such ignorance and not laid at the feet of helpless animals, who play no part except to suffer for us and to die by the hundreds of millions. This is an insult to the Creation, not to mention an ecological disaster from the disposal of bodies. And to make matters worse, much of the research is based upon biased and erroneous science.
Conclusion
Though we have the power over these creatures to inflict our cruelty on them, to do so may have dire consequences, given a Universe that operates on balance. Individuals of compassion and conscience may wish to consider opposing, through words and actions, this Frankensteinian madness.
References
1. Bechamp A (1912) The Blood and Its Third Anatomical Element. In: Montague R Leverson & translator (Eds.), John Ouseley Limited, London, UK.
2. Douglas HE (1923) Bechamp or Pasteur? CW Daniel Co Ltd, England, UK.
3. Christopher D (1991) The Persecution and Trial of Gaston Naessens. Kramer HJ, Tiburon, USA.
4. Christopher D (1991) To Be or Not to Be? A paper presented in an address to L’Orthobiologie Somatidienne Symposium, Sherbrooke, Quebec, hosted by Gaston Naessens.
5. Kalokerinos A, Dettman G (1977) Second Thoughts About Disease/ A Controversy and Bechamp Revisited. Biological Research Institute, Warburton, Australia 4(1).
6. RO Young, SR Young (2010) The pH Miracle. Hachette Publishing, New York, USA.
7. RO Young, Sick T (1999) Reclaim Your Inner Terrain. Woodland Publishing, Utah, USA.
8. Margulis Lynn, Sagan Dorion (1986) Micro-Cosmos: Four billion years of evolution from our microbial ancestors. Summit Books, New York, USA.
9. Lynes, Barry (1987) The Cancer Cure That Worked! Fifty Years of Suppression. Marcus Books, Ontario, Canada, pp.167.
10. Christopher H (1977) Nuclear Evolution. In: Boulder Creek & Cal (Eds.), (2nd edn), University of the Trees Press, USA, pp. 1009.
©2016 Young. This is an open access article distributed under the terms of the, which permits unrestricted use, distribution, and build upon your work non-commercially.
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