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(Taweret, Taurt, Taueret, Thoeris)
Tauret was a predynastic hippopotamus-goddess of pregnant women and childbirth. She was also a mother-goddess who wore the solar disk and cow's horns to symbolize how she helped in the daily rebirth of the sun. She was even called the Eye of Re, his daughter, and the mother of Osiris and Isis.
Tauret was portrayed as a pregnant female hippopotamus with large human breasts, the hind legs of a lion and the tail of a crocodile. She is shown standing on her hind legs and leaning on the symbol for "protection" and holding an ankh.
Tauret was a domestic deity that was greatly revered. Her most common role was as a protectoress of pregnant women. She was often shown with Bes in the birth chamber and she was a prominent assistant at the birth of Hatshepsut.
Tauret acquired an evil reputation because she was said to have been the concubine of Seth. When she sided with Horus in their dispute over who was the rightful claimant to the throne of Egypt following the death of Osiris she showed her kinder nature. | <urn:uuid:63834767-df24-492b-a319-c2bd82df1ec3> | CC-MAIN-2016-26 | http://www.egyptianmyths.net/tauret.htm | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783397842.93/warc/CC-MAIN-20160624154957-00084-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.98777 | 252 | 2.828125 | 3 |
Tyzzer's disease in muskrats
|Title||Tyzzer's disease in muskrats: occurrence in free-living animals|
|Author(s)||G. Wobeser, D. B. Hunter, Pierre Y. Daoust|
|Journal||Journal of Wildlife Diseases|
|Abstract||Tyzzer's disease was diagnosed in four muskrats (Ondatra zibethica) found dead over a 2 month period in a single feed-house in a Saskatchewan marsh. No dead animals were found elsewhere in the marsh, although several hundred apparently healthy animals were trapped during this period. Similarities in the pathology and epizootiology of Tyzzer's and Errington's diseases of muskrats support an hypothesis that these diseases are a single entity.|
Using APA 6th Edition citation style.
Times viewed: 373 | <urn:uuid:b0068f03-05f8-41d9-a11e-53239d664ee3> | CC-MAIN-2016-26 | http://www.islandscholar.ca/scholartest/fedora/repository/ir%3Air-batch6-3344 | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783396459.32/warc/CC-MAIN-20160624154956-00173-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.859232 | 181 | 2.859375 | 3 |
TeachMeFinance.com - explain individual self-defense
individual self-defense 'individual self-defense' is an military term meaning '(DOD) The individual's inherent right of self-defense is an element of unit self-defense. It is critical that individuals are aware of and train to the principle that they have the authority to use all available means and to take all appropriate action to defend themselves and other US personnel in their vicinity. In the implementation of these standing and other rules of engagement (ROE), commanders have the obligation to ensure that the individuals within that commander's unit understand when and how they may use force in self-defense. While individuals assigned to a unit respond to a hostile act or hostile intent in the exercise of self-defense, their use of force must remain consistent with lawful orders of their superiors, the rules contained in joint doctrine, and other applicable ROE promulgated for the mission or area of responsibility'.
About the author | <urn:uuid:5002b1f3-190a-49e1-a370-887f23a1a279> | CC-MAIN-2016-26 | http://www.teachmefinance.com/Military%20Terms/individual%20self-defense%20-.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783396872.10/warc/CC-MAIN-20160624154956-00053-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.936687 | 195 | 2.859375 | 3 |
Are there limits on the kinds of discriminatory statements a teacher in a religious school in Norway can make to his or her students?
Vibeke Blaker Strand, who has studied safeguards against discrimination with respect to the practice of religion, thinks not.
“Protection against discrimination on the national level is interpreted as inapplicable to religion classes at private schools," she says. "Freedom of religion takes priority."
Strand has recently completed her PhD at the University of Oslo's Department of Public and International Law on the issue.
She says that the underpinning of the current legislation explicitly states that oral expression is exempted from laws that protect people from discrimination.
Schools also have complete freedom in choosing their own textbooks, with almost no controls on their content, she asserts.
The combined result is that "existing regulations are grossly insufficient and lack a system for detection of substantial problems that can arise," Strand says. "We urgently need to consider what these schools can be allowed to do and to pass appropriate legislation."
A special responsibility
There were a total of 3000 primary schools in Norway in 2011, of which just 172 were private. These schools had 16,684 pupils out of the country's 614,374 elementary school children. Most of the private schools are Steiner or Waldorf schools, or Christian schools.
Despite the relatively small number of students involved, Strand believes that international human rights conventions give the Government a special responsibility for ensuring that pupils in religious schools are protected from teaching that contains discriminatory content.
“The state is obliged to have regulations ensuring that children aren’t being discriminated against in their education," she argues. "Freedom of expression in religious teachings also provides a wide-open door for the dissemination of discriminatory attitudes. Under current legislation no one can be denied the right to start a religious school on the basis of the choice of religion."
Lots of leeway
Under existing Norwegian laws, Strand says, the rights to freedom of education and freedom of religion could cause problems in three distinct areas: gender discrimination, protection against discrimination on the basis of sexual orientation and protection against discrimination on the basis of religion or philosophy of life.
The problem is that in the context of religion, safeguards against discrimination do not apply to orally expressed statements, so that no limits have been set regarding remarks that have a religious foundation and are offensive to homosexuals or single mothers, as two examples, Strand says.
"Religious teachings or statements could assert that these kinds of people should be looked down on, or that women are subordinate to men, " she said. "An expression isn’t viewed as illegal until it crosses the lines set by § 135 in the Penal Codes, and that provides a lot of leeway.”
One example concerns teaching about homosexuality, she says. “It’s been discussed whether the Penal Codes can be used to hinder teaching that homosexuality should be punished by death," Strand says.
"This shows just how extreme a statement can be before the law could possibly be invoked. It’s easy to envision a wide range of expressions that would be offensive or discriminatory with regard to homosexuals or other groups, which are not strictly illegal, but that would be alarming if they were taught in the classroom.”
Different legal interpretations
The Ministry of Education and Research disagrees with Strand's assessment. Ministry officials say the claim that there are no limits regarding the content of religious instruction at private schools is misleading.
Instead, they say, the teaching at private schools is regulated by Norway's Private Education Act, which states that that private schools must provide education in accordance with a curriculum which is approved of by the Ministry.
"This sets limits and give directions as regards what can be and what must be part of the curriculum, and which textbooks may be used. The teaching and education must conform to an accepted curriculum,” says Department Director Ann Helen Elgsæther, from the Ministry’s Department of Education and Training.
“If a private school fails to teach in accordance with the approved curriculum, or otherwise breaks the regulations of the Private School Act, the school can lose its license and be denied the right to continue operations, or be ordered to repay the financial support they’ve received from the state,” Elgsæther says.
The Norwegian Directorate for Education and Training supervises private schools and has statutory access to school facilities and all relevant information. Elgsæther adds that all pupils in private schools have a statutory right to a good psycho-social environment that promotes welfare and education. Schools are obliged to work actively for the advancement of a good school environment in which the individual pupil feels safe and a sense of social belonging. Offensive statements or actions, such as bullying or discrimination in the teaching process, are totally incompatible with a good psycho-social environment and thus would be illegal.
Intentional or inadvertent violations of the regulations on the part of the school are punishable by fines or jail sentences of up to three months, Elgsæther points out.
Which takes precedent?
Strand disagrees with the ministry’s interpretation, and asserts that discrimination isn’t regulated and defined by the Private School Act. Instead, it is regulated by anti-discrimination statutes, she says.
“To say that pupils are protected against discrimination because discrimination is illegal is circular reasoning. The issue is: What do anti-discrimination laws say about the range of their protection against discrimination? The word ‘discrimination’ itself says nothing about what is illegal,” she asserts.
A major problem is the legal formulation of the anti-discrimination legislation, Strand says. Several essential areas of education in religious schools are outside the jurisdiction of anti-discrimination legislation. Religion lessons and verbal remarks are two areas where regulations are needed to set limits for what can be taught to pupils, as well as when the subject matter being taught is based on religious doctrine, she says.
The manual upon which the Norwegian Directorate for Education and Training bases its supervisory activities fails completely to address the special issues that can arise in religious schools, the researcher adds. The problem is not simply the loopholes in the anti-discriminatory legislation. The inspection system established in conjunction with the private school legislation is also inadequate, she says.
The Ministry of Education and Research asserts that current legislation is sufficient.
“If a private school fails to educate in accordance with the approved curriculum, or in other ways breaks the regulations of the Private School Act, the school can lose its authorization and be shut down, or ordered to refund state subsidies,” says Elgsæther at the Ministry.
A test case
ACE – “Accelerated Christian Education” – is a school programme established in the USA in 1969. Some private Christian schools in Norway used the ACE teachings and ACE textbooks in their curriculum, which led to "the ACE case," in which the appeals committee of the Equality and Anti-Discrimination Ombud was asked to evaluate the situation.
The appeals committee examined social studies textbooks, where for one of the school documents used in the fourth grade, pupils were asked to underline the correct answer to the following: “(Wives, Dogs, Cats) shall obey their husbands”.
Because this was textbook material for use in social studies, the committee decided that it was discriminatory and illegal.
Stand says that because the teaching was in a written form, and because it was not used in a religion class, it was regulated. But had the same idea been presented in a religion class, or had it been stated orally by a teacher, "this same message would be acceptable," she said.
The researcher thinks the main problem today is that certain areas have been defined as exempt from the protection against discrimination.
“In my opinion, current regulations regarding discrimination fail to take into account circumstances that can apply to educational situations, and they inadequately uphold Norway’s human rights obligations,” she says.
Human rights and life philosophy
Strand has also studied ways that international human rights conventions can function as a framework for national formulation of policies. She says there are some areas where the government has the right to change its policy formulations, even if it isn’t obligated to do so. In these kinds of situations, "human rights conventions contribute to highlighting national choices of political strategies and allow for reflection and discussion about them,” the researcher says.
“Another example is the way that the subject of religion and life philosophy is to be taught in Norwegian schools," Strand says. "The issue has been debated for years. The way it is currently taught satisfies all the state’s obligations – it respects everyone’s rights. There is very little leeway for reversing the subject back towards more Christianity.” | <urn:uuid:a6701703-fc39-421f-b39e-27ece7677ed9> | CC-MAIN-2016-26 | http://sciencenordic.com/too-much-freedom-norwegian-religious-schools | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783399106.96/warc/CC-MAIN-20160624154959-00034-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.967307 | 1,803 | 2.953125 | 3 |
Young Swedish men are consuming at least double the recommended amount of salt according to a study carried out by the Sahlgrenska Academy at the University of Gothenburg and Sahlgrenska University Hospital.
"It's alarming that young Swedish men are consuming so much salt, and something needs to be done about it. We can really only speculate on the consequences of such a high salt intake later on in life, in the form of cardiovascular diseases and stroke," says Lena Hulthn, Professor in Clinical Nutrition at the Sahlgrenska Academy.
The study included almost a hundred men in their twenties. Urine samples from all participants were analysed over a 24-hour period. The participants also answered questions about their eating habits. The urine samples showed that the young men were consuming at least two times the World Health Organisation's recommended daily intake of six grams.
"High salt intake can lead to high blood pressure, but we couldn't detect any connection in our study. High blood pressure doesn't usually develop until a person is in their 30s or 40s, since the kidneys' ability to deal with the excess salt deteriorates with age," says Lena Hulthn.
Salt in food is found largely in ready meals such as pizza and frozen meat hash, but it is also in bread, cheese, meat sandwich fillings, fish products, breakfast cereals and other products produced by the food industry. An earlier Danish study has shown that only a tenth of the salt that we consume comes from our own salt cellars.
"The food industry needs clear regulations on how much salt it is allowed to use if we want to reduce total salt intake. One solution could be to follow Finland's example, where all food packaging has to clearly state the salt content to make it easier for the consumer to select products containing less salt," says Lena Hulthn.
|Contact: Professor Lena Hulthn|
University of Gothenburg | <urn:uuid:c9c6f978-dd1d-4246-810d-c507741d4f62> | CC-MAIN-2016-26 | http://www.bio-medicine.org/biology-news-1/Young-men-consuming-an-alarming-amount-of-salt-11403-1/ | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783394414.43/warc/CC-MAIN-20160624154954-00060-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.965977 | 399 | 2.625 | 3 |
Millions of babies suffer various degrees of diaper rash daily! I have seen many rashes and I can tell you, "You can bring your baby relief fast." Many times moms will ask, "What causes diaper rash and what are the signs and symptoms of diaper irritation?" The following are the most common:
Friction Rash - most common where friction is pronounced, such as the inner thighs, or under the elastic of diapers that are too tight.
Irritant Rash - prominent on exposed areas, such as the buttocks. The result of contact with stool enzymes or irritants such as harsh soaps, baby wipes, detergents, or topical medicines. Products that contain mineral oil can actually suffocate baby's skin.
Urinary Wetness - increases skin friction and raises the skin PH which then causes the outermost layer of skin to become unbalanced. With this protective layer disturbed, it is easy for micro-organisms such as yeast or bacteria to invade baby's inflamed skin.
Eczema or Allergic Rash - more common on visible areas, the skin may look like it’s been exposed to poison ivy in reaction to chemicals in certain lotions, soaps or powders.
Heat Rash - in weather that is hot or humid, the infant sweats, but the blockage of sweat glands produces little red bumps or small blisters.
Prickly Heat - causes rash or blotches during hot weather or in a hot environment (the same as heat rash).
Seborrhea Rash - a salmon-colored, greasy rash with yellowish scales that is also worse in the skin folds, usually a reaction to a skin irritant or synthetic ingredient.
Psoriasis - diaper rash accompanied by other signs of psoriasis such as dark red areas with sharp borders and fine silvery scales on the trunk, face, or scalp.
Moms are often astonished that the products they so lovingly use on their baby are actually hurting them. I tell them to look at all the myriad of baby care products out on the market today, then, look at the ingredients!
Most of baby's skin sensitivities are aggravated by the synthetic ingredients in baby care products such as lotions, powders and soaps including doctor recommended ones. Add to this this the lack of breathable materials in today's disposable diapers.
A recent report in Clinical Pediatrics revealed that more than 75 percent of newborns (babies under 1 year) suffer rashes within the first few months of birth, and researchers suspect that contributing factors include the very products that promise to soften, clean, and moisturize children's skin adding that newborn skin is relatively more permeable to topically applied agents than adult skin.
Moms want to know, "What is the best diaper rash solution?" My recommendation is a 2 step plan that is fast and effective:
Step 1) Use a "non-soap" cleaner that is hypo-allergenic and contains only herbal ingredients that are organically grown. Ingredients that are plant based, make a cleanser that is just right for infants, babies and toddlers.
This type of gentle and pure wash should also contain vitamins A, C and E, herbal extracts such as Chamomile, Calendula, and Comfrey.
Remember, what you don't want are synthetic fragrances, colorants, parabens or preservatives.
Step 2) Apply a thick and rich natural diaper rash cream that will repair the skin and provide a layer of protection that is crucial to proper skin repair. A MUST is that it also STOPS any itching while it's working and is hypo-allergenic!
Using a plant based cream filled with vital reparative nutrients as well containing shea butter which acts as a natural occlusive protecting baby's skin from bacteria and acidity is vital.
Letter to Nanette:
After my baby was born, her diapers chafed and irritated the sensitive skin on her inner thighs. I used what you recommended on her, and the redness went away within a day. I refuse to use any of the other baby lotions on her skin because this one is so gentle, it’s unscented, and it just works so well. J.S., Huntley,IL
My 3 month old son had very bad diaper rash for weeks and nothing I tried helped him. It was very frustrating and many times the rash would keep him (and me!) up all night. When I started to use the Hand & Body TheraCream it began to soothe his bottom right away. Within days his rash was gone and was I ever relieved! My baby and I are thrilled! Sharon P., MN
Please Note: Disclaimer - These statements have not been evaluated by the FDA. The information, products, answers to viewer questions as well as comments and testimonials from viewers are not intended to diagnose, treat, cure, or prevent any disease. | <urn:uuid:db833f01-f103-4d1c-b6f3-1fffa2a2ff73> | CC-MAIN-2016-26 | http://www.skin-remedies.com/diaper-rash.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783393997.50/warc/CC-MAIN-20160624154953-00149-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.956383 | 1,014 | 2.53125 | 3 |
China Blocks Uncensored Version of Wikipedia Ahead of Tiananmen Square Anniversary
Sina Weibo, the country’s popular Twitter-like service, has also been observed suddenly experimenting with more sophisticated censorship techniques.
In the days leading up to the 24th anniversary of the Tiananmen Square massacre on Tuesday, the Chinese government has been closing some cracks in its system of Internet censorship, known as the Great Firewall, according to reports.
On Monday, access to an uncensored version of Wikipedia was cut off in the country, according to Greatfire, an organization that monitors online censorship in China.
Beginning Oct. 2011, Wikipedia began supporting encrypted connections to all local language versions of its behemoth encyclopedia, which prevents Chinese censors from selectively blocking articles from the site. As of Monday, however, only the old, unencrypted version of the Chinese-language Wikipedia -- which is missing hundreds of entries on politically sensitive topics -- is accessible in the country.
Most analysts have linked the crackdown to the always politically sensitive anniversary of the June 4, 1989, massacre of pro-democracy student protesters in Tiananmen Square. Hundreds of students were killed in the military suppression of the protests, but the Chinese government has yet to provide an official death toll, as it still views the protests as criminal and “counter revolutionary.”
Greatfire also reported that it had noticed a shift in the censorship tactics used on Sina Weibo, China’s wildly popular Twitter-like microblog service. In the past, the site blocked searches for hundreds of keywords deemed politically fraught. But as of Friday, for example, searches for “June 4 incident” -- as the event is known in China -- began yielding results.
In the past, searching for this hot-button issue would yield an error message or a statement saying that the given search term had been blocked for legal reasons. For less overtly sensitive topics, searches would result in a filtered list of harmless posts that were several days old – suggesting both that the search term was censored and that it took several days for Sina to winnow politically inflammatory content from its millions of posts.
As of Friday, search results for sensitive topics began leading to filtered, harmless results that were just several hours old -- with no notice that the tweets had in any way been censored. From the user’s end, this new speed and sophistication in filtering makes it harder to tell which search terms are being meddled with -- instead, it will often appear as if a censored search term is being openly discussed, but nothing controversial is being said about it.
“This is an example of censorship at its worst,” wrote Greatfire. “Users suspect their search term might get blocked before they search but instead of a censorship notice they are led to believe that what they are searching for is not sensitive, plus not many people are saying anything interesting about the keyword anyway.”
On Friday, the U.S. State Department issued a statement of remembrance for those killed in Tiananmen Square, calling on the Chinese government to "end harassment of those who participated in the protests and fully account for those killed, detained or missing."
Chinese foreign ministry spokesman Hong Lei replied with a statement demanding that the United States “discard political prejudice, correctly treat China's development, immediately rectify its wrongdoings and stop interfering in China's internal affairs so as not to sabotage China-U.S. relations." | <urn:uuid:a8acde41-65b1-4b3b-8ea0-6c89a0477483> | CC-MAIN-2016-26 | http://www.hollywoodreporter.com/news/china-blocks-uncensored-version-wikipedia-561827 | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783395613.65/warc/CC-MAIN-20160624154955-00172-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.966468 | 704 | 2.6875 | 3 |
: Critical thinking is a phrase that is being heard frequently in nursing education. Nurse educators are encouraged to teach students to think critically because of the higher-order thinking skills that are required in our complex health care delivery system. The challenge to educators is the selection, development, and implementation of appropriate feaching strategies. This article describes a variety of strategies for teaching critical thinking within the context of nursing.
(C) Lippincott-Raven Publishers. | <urn:uuid:37de790f-73f5-4b54-a8ac-412120f8683a> | CC-MAIN-2016-26 | http://journals.lww.com/nurseeducatoronline/Abstract/1991/16060/TEACHING_STRATEGIES_FOR_CRITICAL_THINKING_.7.aspx | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783397565.80/warc/CC-MAIN-20160624154957-00027-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.946012 | 91 | 3.359375 | 3 |
Understanding the Scriptures
|Parable(v. 1)||A short story that teaches a lesson or moral|
|Sowers, soweth(vv. 2–3)||Planters, plants|
|Tares(vv. 3, 6–7)||Weeds|
|Reap down(v. 5)||Cut down and harvest|
|Heirs(v. 9)||Receivers of a gift or blessing by right, inheritors|
Doctrine and Covenants 86:5—Angels Ready to Reap
Speaking to a group of temple workers in 1894, President Wilford Woodruff said: “God has held the angels of destruction for many years, lest they should reap down the wheat with the tares. But I want to tell you now, that those angels have left the portals of heaven, and they stand over this people and this nation now, and are hovering over the earth waiting to pour out the judgments. And from this very day they shall be poured out. Calamities and troubles are increasing in the earth, and there is a meaning to these things. Remember this, and reflect upon these matters. If you do your duty, and I do my duty, we’ll have protection, and shall pass through the afflictions in peace and in safety” (quoted in Susa Young Gates, “The Temple Workers’ Excursion,”The Young Woman’s Journal,Aug. 1894, 512–13).
Studying the Scriptures
Do activity A or B as you studyDoctrine and Covenants 86.
Interpret the Parable
Apply the Message
Write about an experience you had, or one any young person might have, to which the meaning of the parable of the wheat and the tares could be applied.
How does the message ofDoctrine and Covenants 86:8–11relate to the parable of the wheat and the tares? | <urn:uuid:d1b4bbcb-b203-467b-8352-68e6aa1e5494> | CC-MAIN-2016-26 | https://www.lds.org/manual/doctrine-and-covenants-and-church-history-student-study-guide/the-church-in-ohio-and-missouri/doctrine-and-covenants-86-the-parable-of-the-wheat-and-the-tares?lang=eng | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783404826.94/warc/CC-MAIN-20160624155004-00160-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.888104 | 413 | 3.125 | 3 |
Take a sneak peek at the new NIST.gov and let us know what you think!
(Please note: some content may not be complete on the beta site.).
Ni-63 is of considerable interest and importance in radionuclidic metrology as well as for radiation protection surveillance around nuclear facilities.
Generally, 63Ni has great utility as a low-energy b- calibration standard because of the favorable combination of long half-life (T = 100 a) and b- endpoint energy. Primary standardizations of 63Ni have been actively pursued by national radionuclidic metrology laboratories for over 40 years. As a medium-energy [Eb(max) = (66.945 ± 0.004) keV; Eb(ave) = 17.43 keV] pure-beta emitter, it is often used as a test case for evaluating measurement proficiency in international comparisons. In addition, assays of 63Ni are often performed because 63Ni is a principal neutron-activation product of nickel, found at nuclear-power reactors and their environments. It is also one of the radioactive and chemically corrosive contaminants in high-level liquid-waste at nuclear fuel storage and reprocessing facilities. A new primary radioactivity standardization of 63Ni was performed. This standardization was used to support SRM 4226D which is presently out of stock. The standardization links all previous 63Ni standardizations that have been performed over the past 42 years (1968; 1984; 1995; 2006) adding another point for the determination of the half life by radioactive decay. The primary standardization of 63Ni was performed by CIEMAT/NIST 3H-standard efficiency tracing (CNET) and the value confirmed by the triple-to-double-coincidence ratio (TDCR) method. The certified massic activity of the new issue of 63Ni is wholly consistent with the decay corrected certified activity in SRM 4226C (issued in 1995), SRM 4226B (issued in 1984) and SRM 4226 (issued in 1969) using the previously derived half-life value of (101.1 ± 1.4) and hence confirming the extant value. The present agreement with the previous issues are +0.6 %, +0.9 % and +0.5 %, respectively. | <urn:uuid:9abd2c7e-c577-47c4-9d51-92701540788c> | CC-MAIN-2016-26 | http://www.nist.gov/pml/div682/grp04/ni63.cfm | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783396106.71/warc/CC-MAIN-20160624154956-00031-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.931409 | 477 | 2.8125 | 3 |
A new sight appeared on Saturn earlier this month: A massive, swirling storm with a tail that cuts across the gas giant. Amateur astronomer Anthony Wesley, who was the first to spot the Earth-sized scar on Jupiter last summer, took the first pictures of this storm. And then on Christmas Eve the Cassini spacecraft beamed home its own ravishing images.
The spacecraft took images of the planet on December 24th, returning — as usual — jaw-dropping pictures of Saturn showing the storm. This image, taken with a blue filter, shows the storm clearly. The main spot is huge, about 6,000 km (3600 miles) across — half the size of Earth! Including the tail streaming off to the right, the whole system is over 60,000 km (36,000 miles) long.
There’s an added bonus in these images: the shadow of the rings on the planet’s clouds is obvious, but the rings are nearly invisible! You can just make out the rings as a thin line going horizontally across Saturn in the first image. These pictures were snapped when Cassini was almost directly above the rings, which are so thin they vanish when seen edge-on. Actually, that works out well as otherwise they might interfere with the view of the storm in these shots.
For more details, check out the rest of Phil’s post at Bad Astronomy.
80beats: By Demolishing a Moon, Saturn May Have Created Its Rings
80beats: Mysterious Smash on Jupiter Leaves an Earth-Sized Scar
Bad Astronomy: Saturn rages from a billion kilometers away | <urn:uuid:4f51aecd-bdca-4c14-8b95-0eaf44f6adc0> | CC-MAIN-2016-26 | http://blogs.discovermagazine.com/80beats/2010/12/28/cassini-catches-a-glimpse-of-an-enormous-storm-on-saturn/ | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783395166.84/warc/CC-MAIN-20160624154955-00054-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.927327 | 332 | 3.171875 | 3 |
3-d printing services have been there for some time now. However, these developments could have been realized much earlier if this technology had been rolled out to the public. Initially, the use of 3D printing services was somehow restrictive, and only a few organizations could use this technology. With the need for this technology in various fields, most manufacturers and designers have a reliable tool for streamlining and optimizing their operations.
Why 3-D Printing
The idea behind 3-d printing was to help both the developers and the customers. For the designers and manufacturers, this printing method provides an economical and faster mode of production. One of the core reason behind this is that the cost of raw materials, tooling costs, and the usability are enough proof that this technology will be with us for some time. Moreover, 3-d printing is divided into some subcategories that make it viable for performing specialized tasks like translating CAD designs, rapid prototyping, and 3-d scanning methods.
This is a vital tool in creating models from existing designs. Ideally, these features allow you to convert a physical body into digital form. From there, the design team can make the necessary adjustments and modifications. It is a handy tool for correcting manufacturing errors or in reverse engineering methods.
The good thing about of 3-d printing is that it works perfectly with mode computer designing tools. As such, the software can take the digital design in mot CAD suites and convert it into a physical design of the product.
In design, the prototypes serve as a reference or starting point when making the final product. With 3-d printing, the design team benefits from sin a cheaper model before releasing the final model. Notably, the ability to create prototypes economically is the hallmark of 3-d printing.
Benefits of 3-d Printing
Thanks to the development of 3-d printing, most business can now reduce their production cost and optimize their production process. Small and mid-sized business can now use a technology that was initially left for established corporations. With it, manufacturers benefit from reduced lead times, low production costs, optimized iterations, and more profits.
3-d printing presents a broad range of operational and economic benefits to an organization. As such, it is an indispensable resource for any organization. With it, the business can optimize its manufacturing cycle, reduce production costs and most importantly sell quality products. | <urn:uuid:e0de9730-f325-40fc-87ab-de1547324b34> | CC-MAIN-2016-26 | http://www.bkaphoto.com/ | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783396538.42/warc/CC-MAIN-20160624154956-00084-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.955015 | 482 | 2.828125 | 3 |
The Kaveri Purana is a part of Skanda Purana, one of the last Puranas written. Some researchers see Kaveri Purana as a way of trying to integrate Kodavas to Hindu society by explaining that they are the progeny of Kshatriya kings and Sudra women. Kodava culture did not recognize the Aryan varnashrama and hence did not have caste systems. This helped to diffuse any friction between Kodavas who were radically different than their Hindu neighbors.
The following poem gives us a sense of devotion of Kodavas to Mother Kaveri:
Sri Mula kanniye,
(O primeval sacred maiden)
O Mother Kaveri,
Wear pommale* Kodagu as a garland, O Mother!
Why do you need a jommale**?
Why do you need a garland of flowers?
Wear the golden land of Kodagu as a garland, O Mother!
O sacred form of Parvati
You descended to earth as a Brahmin’s daughter,
And to cleanse the sins
Of all the sinners
You flowed from the kundike*** to the Eastern sea.
To all the proud ones
You are merely flowing water.
But to the suffering, you are sorrow-relieving holy water.
Those without children
Those without family
And those weary with suffering, bless and care for them, O Mother!
– Nadikerianda Chinnappa
The family unit of the Kodavas is called the okka. It is a joint patrilineal clan with males of common ancestry. The male members of an okka share an okka name. Currently there are about 1000 okka names and families in Kodagu. Traditionally all the members of an okka lived in a large ancestral home called ain-mane (ayyangada mane – House of the Elders). Usually the ain- mane has a courtyard in the front surrounded by thick mud walls and bamboo thatched roof. Out houses for additional living space were also common. Ain-mane is surrounded by large property (jamma) and by huts of laborers attached to the okka, who provide necessary services. This cluster of homes and property form the nucleus of a village called ur. A group of ur or villages is called the nad. A number of nads make a sime. Traditionally there were eight simes in Kodagu. The land belonging to the okka is cultivated jointly by the family members and cannot be partitioned or sold.
The oldest member of the family is the head of the okka and is called pattedara or koravukara. It is a hierarchy that is passed on to the eldest member of the clan by right. Similarly each ur(or ooru), nad and sime has a headman called as takka. The takkas settled disputes and imparted justice after consultation with other elders.
Girls and boys from one okka cannot marry within the same okka. However, cousin marriage between children of brother and sister is accepted (but not between children of two brothers or two sisters). Once married, a girl assumes the okka name of her husband. Mother is held in high esteem in Kodava society. Mother is the first one to bless a young married couple or a journeyman. Unlike Hindu society, a widow is still allowed to participate in happy occasions like marriages of her children. She is the principal figure to conduct the marriage ceremony that traditionally is conducted without a Brahmin priest. A widow is allowed to remarry and this is a common practice as it is fully accepted.
Kodavas are primarily ancestor worshippers. At their homes they keep an idol of their ancestors to whom they offer prayers and obeisance. It is usually made of clay or wood or covered with sheet metal, and housed in a shrine (kaimada) built near the entrance to the ain-mane. The founder of each okka, the Karanava, is worshipped by the members of each okka. Sometimes it is simply kept on a platform under a sap-exuding tree near the entrance of ain-mane. Some okkas conduct a karana kola, a dance of the ancestral spirit during which a Malayalee migrant dresses in elaborate colorful clothing and dances in a trance and acts as an oracle. During this ceremony he is symbolically possessed by the karanava, the original founder of the particular okka. In every home a lamp called Nellakki Bolucha is lit in honor of the Guru Karana. The lamp in the central hall is lit by the embers of the kitchen hearth every day. Kodavas were also nature worshippers revering sun, moon, earth and fire. Fire of the kitchen hearth is especially sacred.
Kodavas did not have allegiance to Hindu gods, though more recently Hinduism has influenced them enough that they visit Hindu temples. The influence is more gradual as more and more people came in contact with Hindus of Kerala and Dakshina Kannada. Thus Bhagavathi and Chaundi (Chamundi) became recognized goddesses. Mother Kaveri is their Goddess figure and the festival of Kaveri’s birth, Tula Sankramana attracts Hindus from neighboring districts and states to bathe in the sacred river. This custom surely is a later addition to Kodava custom as the concept is purely Aryan in its proceedings. Another goddess, Pannangalatamme is the patron goddess of the original inhabitants of Kodagu. She has a number of brothers as gods; chief among them is the Shaivite Igguthappa who controls the monsoon rains and coffee bean showers. His brothers are Pemmaiah, Thambipan, Paloorappa and Thirunalli. Some of these brothers are Vaishnavite gods, a clear indication of Aryan Hindu influence on this mountain community. Today all the gods of Hindu pantheon are recognized by Kodavas and they are fully integrated into Hindu society. Due to their martial traditions Kodavas consider themselves as Kshatriyas.
Dresses and Dances
The old traditions of Kodavas, before embracing Hinduism are unique and vastly different than Hinduism. None of the festivals, marriages, births or deaths is conducted by a Brahmin priest. Libations and meat are served in these occasions. Some of the customs are reminiscent of old Eurasian and pre-Christian Greek traditions.
The traditional costumes of Kodavas resemble that of the people of Middle East, with a long coat (Kuppya) down to mid-calf with a band of gold trimmed sash (chele) with tassels, across the waist tied in a bow. The ends of this sash hang gracefully over the left thigh.
The coat has a V-neck showing undergarments at the neck and arms. The kuppya is a sort of double-breasted coat with the right wrapping over the left side and stitched on the left side of the chest and trunk. It comes in various colors. The headdress is a piece of cloth (vastra) tied around the head, a turban, with the loose end hanging in the back at the nape of the neck. A bridegroom wears white kuppya with a brocaded white turban and a red brocaded chele.
Sports and martial arts like sword wielding are extolled, and hence there are some traditional swords and machetes that are used during ceremonies as well as part of the ceremonial costume.
The most important is the peeche kathi, which is an ornamented dagger that can be worn on the waist band.
During wedding ceremonies, peeche kathi is used to break coconut and scoop out the inside shavings and offered to others. An odikathi which is a sword with a broad head is used to cut trunks of banana trees in a ceremonious fashion during weddings. These rituals are performed by a member of the groom’s party during the initial offerings by the bride’s party.
Kodava women dress in a manner that is unique to their community. The pleats of the sari are tucked into a band around the waist. The pallu is brought around the back and then on to the right shoulder and tied in the front with a knot (molakattu). Chemise and ankle length petticoats are worn under the sari. A long-sleeved jacket with or without a close collar is worn as a blouse. Married women cover their heads with a cloth, five feet on each side with edges over the ears and then tied in the back with ribbons. This head garment is called a chowka. A widow will wear only white. Marriages of widows are not only accepted but also encouraged.
Kodavas are very fond of dancing. Folk songs are sung while dancing. Kombat is a dance when the dancers are holding horns of stags, Couriat, with dancers holding yak-tails, piliyat, with peacock feathers, bolakat, with dance done in the temples around a lamp, and kolat, with dancers holding sticks are all commonly performed dances. Ummalat is a dance by women holding cymbals. Even in most of the religious functions, liquor and meat are not taboo. This has given the Kodavas a reputation as fun loving people with little inhibitions, who extol physical strength and skills.
Kodavas are an ancient society, origins of which are unknown, who made their homes in the slopes of Western Ghats in the southern part of the state of Karnataka. They are fiercely independent people with a proud martial tradition. Though they form only about 20% of Kodagu, they are the dominant group, synonymous with the region. The customs followed by the Kodavas are strange and different when compared to Hindu customs. Over recent centuries, Hindu culture has influenced the Kodavas immensely but yet they still have maintained their uniqueness. Caste system was unknown to them and they treated the low caste Hindus as equals and did not subscribe to the Brahmanical dominance of Hinduism. Their worship, weddings and death ceremonies do not call for a Brahmin priest to preside over them. They are culturally liberal and their women are allowed to marry again if widowed or divorced. The Kodavas also dress differently and the men wear tunics similar to some of the Middle Eastern or Eurasian tribes. The women of Kodagu are known for their beauty and men are ruggedly handsome. They have their own language, without a script, which is thought to be one of the Dravidian languages of South India. Due to its geographical location, the Kodava language is influenced by Kannada, Malayalam and Tulu languages.
It is also remarkable that Kodavas contributed little to fine arts, music, painting or sculpture. Because of their isolation, and the wild life around them, they became adept at hunting and self-defense. Disease and death due to poor access to health care and deadly malaria had decimated their population for many centuries. Only in the last century or so the population of Kodavas reached 100,000. Their population had been further trimmed by Hyder Ali and Tippu Sultan, yet the Kodavas refused to be ruled by the foreigners and held the Muslims at bay. Tens of thousands of Kodavas had been killed by the invaders. They had not been dominated by anyone else until the British took over rule in the year 1834 by trickery.
(Image of Boverianda Chinnappa, and Nanjamma who translated Pattole Palame into English.)
The Kodavas are hospitable and pay much attention to personal hygiene and cleanliness. They strive to keep their homes and surroundings clean and neat. The freshness of jungle with rain forest, the altitude of a hill station with its pleasant summers, and the fascinating people of Kodagu with their quaint customs makes Kodagu a worthy place to visit.
Chinnappa, Nadikerianda: Pattole Palame (Translated by Boverianda Nanjamma and Chinnappa)
Ponnappa, Lt. Col. K.C.: A Study of The Origins of Coorgs
Ponnama Vasudev: Personal Communication | <urn:uuid:3b171fd3-8911-4453-8ef0-69fecb74b757> | CC-MAIN-2016-26 | http://cms.boloji.com/index.cfm?md=Content&sd=Articles&ArticleID=8992 | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783397111.67/warc/CC-MAIN-20160624154957-00174-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.961371 | 2,575 | 3.828125 | 4 |
Creating nice Orbs in Photoshop is the simplest way of doing it. But it is not that simple in Illustrator compared to Photoshop. This tutorial will make you learn how to create a nice Glassy orbs simply and quickly. Not only that you will also learn how to create gradient with opacity which is not a feature of Illustrator. Here are the steps
1. First you have to create a document of any size. Here size is not a matter because it is easy to adjust size of a vector graphics to any other size without losing quality. Then take Ellipse Tool and make a circle in the center of your document. Press gradient button with the circle selected this will create a nice radial gradient. For adjusting the gradient you can adjust it from the gradient palette, if you haven’t seen that then go to Windows>Gradient or press F9. Create a similar gradient that I have created on the right. You can use any color, but in the left, color should be light and in the right, color should be darker. Slide the little diamond towards the right, now the darker color can be visible only in the outside of the circle.
2. Select the Ellipse Tool, then in the top part of your circle create an ellipse and fill it with white. Now you should get an image that looks similar to the image in the right. Copy this layer by dragging it to 'Create New Layer' icon on the bottom of the layers palette. Create a gradient with white on top and black on the bottom.
3. This step is for transparent gradient. For selecting both the ellipses you must hold the CTRL button and click on to the small circles in the layers palette. If you have done that correctly then there will be two blue squares in you layers palette. Now go to Transparency palette and choose Make Opacity Mask as shown in the figure below. If you don’t see this window then go to Window > Transparency or press Shift+F9.
4. Here is your result. If you have done every procedure neatly and correctly then you will definitely get an image like one given below. | <urn:uuid:61bceb98-9fe1-408d-a458-2b7abd9a6e56> | CC-MAIN-2016-26 | http://www.maadesigns.co.uk/illustrator/glassyorbs.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783398075.47/warc/CC-MAIN-20160624154958-00009-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.875353 | 436 | 2.96875 | 3 |
Help!! Can a component of a vector be greater than the vector's magnitude?
Get this answer with Chegg Study
Practice with similar questions
Can the x-component of a vector be greater than the magnitude of the vector? How about the y-component? Explain.A: See answer
Four vectors all have the same magnitude. Vector 1 is at 30, Vector 2 is at 135, vector 3 is at 240, and Vector 4 is at 315. What vector has the greatest magnitude x-component and which vector has the greatest magnitude y-component?A: See answer | <urn:uuid:2414622b-825e-4cd6-a079-9739bdf87ed7> | CC-MAIN-2016-26 | http://www.chegg.com/homework-help/questions-and-answers/help-component-vector-greater-vector-s-magnitude-q461990 | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783396106.25/warc/CC-MAIN-20160624154956-00009-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.90457 | 119 | 2.90625 | 3 |
Integrated Solid Waste Management
Roger W. Flint
Director, Public Works & Utilities
City of Spokane, Washington
Chair, APWA Solid Waste Management Committee
Throughout the United States, solid waste management continues to be a major struggle for communities. Past practices often led to environmental problems, and now we must not only clean up the sins of the past but build systems to deal with our waste responsibly in the future; simply disposing of our waste in a landfill is no longer the only option.
To encourage positive steps, some states have mandated reductions of 50 percent in the total waste that has historically been disposed of by the community. Some communities have already established or are in the process of establishing mandatory recycling programs to meet these goals and, in states like California, we are seeing initiatives that are pushing for zero waste.
Because of this new focus, proper management of our solid waste is no longer hidden from public view. Dealing with our waste in a cost-effective and environmentally sensitive manner is now a major component of good public policy. One way to deal with this complicated issue is for communities to implement what are called Integrated Solid Waste Management Systems (ISWMS).
What Is Integrated Solid Waste Management?
ISWMS combine a variety of disposal, recycling, and reuse options into a custom program that will meet the goals and needs of an individual community. An effective ISWMS program will respond to the local waste stream characteristics, have a built-in flexibility to deal with ever changing regulations and account for fluctuations in markets for recycled material.
Transfer station recycling center
Because no single solution completely answers the question of what to do with our waste, each community has its own unique profile for dealing with its solid waste. The composition of the waste also varies depending on factors such as population, density, how much commercial, manufacturing and industrial business in an area and even the weather. The views and attitudes of your citizens toward varied options will greatly impact your decisions. Community differences and waste compositions are two reasons why no single solution to waste management has been accepted as the absolute best method for managing the waste stream. Therefore, each community must develop its own best approach to managing waste, even though the basic options available to each community are certainly similar.
What are the key components?
In developing the best strategy for an ISWMS we must identify the highest levels at which each type of material can be recovered. To do this we start with waste reduction. Waste reduction is using less and reusing more, thereby saving material production costs, resources, and energy in the first place. At the bottom of the process is final disposal of the remaining material that could not be reduced, reused or recycled.
While ISWMS are designed to fulfill regulatory requirements, they often provide cost savings over the standard practices of disposal as well. The cost to reduce waste and collect and process recyclables is generally lower than costs of other disposal practices.
Planning is an important component
At the City of Spokane, Washington, where I work, we are updating our county's Comprehensive Solid Waste Management Plan (SWMP) with an eye toward the next 20 years. Our goal is to forecast trends and provide direction for county-wide solid waste decisions both now and into the future. These forecasts not only look at how much garbage we will be creating but also attempt to project the categories of garbage and what we are going to do with it all. It is difficult to project that far into the future, so we review our plan every five years and revise or amend it in order to remain current and provide for best practices. This plan helps us keep on track with the optimum methods required for us to maintain a truly Integrated Solid Waste Management System.
The term "solid waste" includes many components that range from recyclables, moderate-risk waste, construction and demolition debris, organic material, and the other usual trash you think of when you hear the term "solid waste." As professionals, we must do our best to provide information to our citizens and advise our policy makers as to "best practices" that will protect our communities both financially and environmentally. Everyone wants to do the right thing—knowing what's right for your own community is the first step in developing an Integrated Solid Waste Management System that will work for your citizens.
Roger W. Flint can be reached at (509) 625-6272 or [email protected]. | <urn:uuid:da84f03d-2dff-4561-ab0d-623a0241a463> | CC-MAIN-2016-26 | http://[email protected]/Resources/Reporter/Articles/2006/3/Integrated-Solid-Waste-Management | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783397695.90/warc/CC-MAIN-20160624154957-00000-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.942533 | 897 | 2.703125 | 3 |
How to use your camera's white balance controls
The human eye has a lot of amazing capabilities. It can see in 3D, it has continuous auto-focus, and it is so light-sensitive that it can detect a single photon of light. Amongst these and other astounding feats is the ability to perceive color correctly under any lighting conditions. If this seems like a ho-hum achievement, consider that we have yet to develop an imaging technology that can do this. Film can't, and neither can digital sensors.
What is white balance?
The problem is that different types of light shine with different colors. Sunlight, for example, shines a very blue light (no, our sun does not cast yellow light; take a look at your shadow next time you're outside and you'll find that it's slightly blue), and incandescent light bulbs shine very red. While your eye can adjust automatically to these different light sources, so that color appears correct under each of them, your digital camera must be calibrated to a light source to properly represent color. This calibration process is called white balancing.
If you think back to elementary school, there was probably a day that you learned about rainbows and prisms, and how both of these split light into its component colors of red, orange, yellow, green, blue, indigo, and violet. In other words: white light contains every other color. The idea with white balancing is that if you can get your camera to properly represent white, then all other colors will be correct.
Choose a white balance preset
By default, your camera is configured to use its auto white balance mode. When in this mode, the camera analyzes the scene and tries to determine the best white balance—the one that will yield the most accurate colors. These days, the auto white balance mechanisms on most cameras are very good, and will almost always yield accurate results when shooting in bright daylight, and several other types of light. However, even the best auto white balance system can begin to fail when shooting in shade.
I shot an image in the shade using the auto white balance setting on a Canon EOS 5D Mark II. While the image doesn't look terrible, it is a little "cool"—the subject's flesh isn't quite as warm and healthy-looking as it should be. There are multiple options for correcting this problem.
Most cameras include white balance presets for different lighting situations—usually daylight, shade, cloudy, tungsten, flash, and fluorescent (of which there are often two types). I switched the camera to its Cloudy white balance preset and tried again. Some cameras have a dedicated Shade preset, but mine doesn't. However, a cloudy day is very similar to shade, so it was a good choice.
Set your white balance manually
Shade is not the only type of light that can cause problems. Mixed lighting—sunlight streaming through a window into a fluorescent-lit room—can also play havoc with the white balance in your camera, yielding images with bad color casts. Or, perhaps you're shooting in tungsten light, but standing next to a bright yellow wall. Even though your camera's tungsten white balance might normally yield very good results, the yellow wall can cast the light into a color range that your camera's preset doesn't work for.
For this reason SLRs, and many point-and-shoots, include the ability to define white balance manually. The process different from camera to camera, but the general procedure is the same: Place something light gray (or, in a pinch, white) within the light of your scene and fill as much of the frame with that object as you can. This is your white balance target.
Now activate the camera's manual white balance process. On some cameras you'll need to take a picture of the target, while in others you'll simply frame the shot and hold it while the camera analyzes the target. (If your camera requires you to take a picture of the white balance target, then you'll have an additional step wherein you tell the camera's manual white balance feature to use that specific image.)
I used manual white balance to retake the same image, and as you can see in the photo on the right, it yielded better results than the camera's Cloudy white balance preset.
If you choose to set your camera's white balance manually, you can also use a white balance card, such as the Raw Workflow WhiBal G6 pocket card. The small, $21 card is specifically designed to be a white balance target. It's lightweight, and spectrally neutral, meaning it doesn't have a color cast of any kind. What's more, it's gray all the way through, so if it gets scuffed, you can just sand it off to return to a gray surface.
Remember that a white balance target needs to go within the light that's striking your scene. If you simply hold it in front of your camera, you may not get a good white balance, because you might be standing in different light from your subject.
Don't count on post production corrections
Because digital image editing software is so powerful, a lot of people think "I don't have to worry about white balance, I'll just fix my image in post production" but this is the wrong approach to take for white balance if you're shooting JPEG images. That's because it's often extremely difficult to fix a JPEG's bad white balance with a photo editor, and sometimes outright impossible. For those times when you can fix it, you may find that performing any additional edits leads to bad artifacts in your image, such as shadow areas that end up looking chunky and banded. Therefore, it's best to get white balance right in-camera when shooting JPEGs, both to save yourself editing hassle later, and to ensure good results. Alternatively, you can choose to shoot raw.
The Raw solution
If you want to avoid white balance troubles altogether, just shoot in raw mode. One of the great advantages of raw files is that you can alter the white balance in a raw file after you shoot, and achieve the exact same results as careful, manual white balance.
For times when you forget to white balance, or when it's impossible to achieve correct white balance (low-light shooting, shooting a distant object in a different type of light from where you're standing, or shooting stage productions lit with multiple-colored lights can all be impossible manual white balance situations) the ability to alter a raw file's white balance can mean the difference between getting and missing the shot.
Film photographers have to be certain that they use film that is balanced for the type of light in which they are shooting, and if that isn't possible, then they have to work hard to add gels to lights and windows to correct the light for their film. Digital photographers have it much easier, but only if they take the time to learn and use their camera's white balance settings.
[Macworld senior contributor Ben Long is the author of Complete Digital Photography, fifth edition (Charles River Media, 2009).]
MSRP: $2,699 (body only)
- Expanded ISO range
- HD video
- Great image quality
- Great interface
- New RAW modes have a slight color shift
- Cheaper cameras available with larger feature set | <urn:uuid:13541585-851c-4cdf-8409-ebb67f3eb151> | CC-MAIN-2016-26 | http://www.macworld.com/article/1150860/whitebalancebasics.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783396949.33/warc/CC-MAIN-20160624154956-00179-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.943142 | 1,504 | 3.125 | 3 |
You have about 5 million hairs on your body. A small portion of these is found on your head, maybe 100,000 — 150,000.
The protein that makes up your fingernails and skin, keratin is also what makes up your hair. The hair follicle is a sack that surrounds the hair root. The root is provided nourishment from surrounding blood vessels. Hair follicles develop while you are in your mother's womb — follicles are not formed after birth.
The hair is produced in the papilla at the base of the follicle. The papilla is nourished by blood flow and provides nutrients for the growing hair.
In both men and women, the male hormone androgen regulates hair growth. The growth of the hair on your head is not directly related to androgen levels, but is influenced by the amounts of DHT, dihydrotestosterone. | <urn:uuid:01bb8cfd-d91c-4118-8370-897213e8b475> | CC-MAIN-2016-26 | http://www.abbysguide.com/hair-loss/guide/understanding-hair.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783396945.81/warc/CC-MAIN-20160624154956-00159-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.966423 | 181 | 3.03125 | 3 |
PG&E is doing its part to conserve water during our near-record drought.
The utility company has decided to leave all of the water in Butte Creek alone this summer to protect Chinook salmon that swim there.
PG&E said they usually divert the water into the Centerville Canal to release it downstream to cool down the water and spread out the salmon, but crews have been noticing the salmon have been swimming upstream to get cooler water.
So they decided to let Mother Nature run its course.
"It's a drought year,” said Paul Moreno, spokesman for PG&E. “There really isn't enough water to run the canal as it is to make it efficient. So we are leaving that water in Butte Creek for the benefit of the salmon."
PG&E used to gather the water to create energy at the Centerville power station but it has been offline for three years now due to a faulty pipe.
PG&E crews will also release more water from their power station and reservoirs on the Feather River in case the water gets too low in Butte Creek. | <urn:uuid:729640fe-32c7-42e4-ae02-c0e7bb960dde> | CC-MAIN-2016-26 | http://www.krcrtv.com/news/local/pge-cuts-water-usage-due-to-drought/26593992 | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783397795.31/warc/CC-MAIN-20160624154957-00025-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.973051 | 225 | 2.78125 | 3 |
University of Wyoming researchers are on a quest to discover why big-city pollutant is now appearing in sparsely populated area
The March 22 issue of Upstream, The International Oil & Gas Newspaper, includes several articles on the Upper Green River Valley in Wyoming. One of the articles, "Field working to find quality solution," discusses the work of Rob Field (pictured at right with his instrument laddened SUV) and researchers at the University of Wyoming who are driving thousands of miles through the Pinedale Anticline natural gas field to find out why a big-city pollutant is appearing outside Pinedale, Wyoming, which has a population of 2030.
The article describes what the researchers are doing, and how they are doing it. "The back of Field’s sports utility vehicle whirs with high-powered scientific instruments connected to rooftop sensors that will measure concentrations of ozone, nitrogen oxides (NOx) and methane, as well as weather conditions," and "The methane detector, made by air quality instrument specialist Picarro [G2204 analyzer], is calibrated with such precision that it ticks up slightly when we pass a herd of cows." | <urn:uuid:d2dc7ec6-ac3c-4e48-8e9b-face00bb6a50> | CC-MAIN-2016-26 | http://www.picarro.com/community/blog/university_of_wyoming_researchers_are_on_a_quest_to_discover_why_big_city_pollutant_i | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783399428.8/warc/CC-MAIN-20160624154959-00198-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.9644 | 235 | 2.9375 | 3 |
By Breanna Giovanniello ’16
Environmental activists have recently taken to intertwining the issues of the environment with human rights abuses. The amalgamation of these two movements is more widely known today as environmental justice. The principle of environmental justice asserts that no people, based on their race or economic status, should be forced to bear a disproportionate burden of environmental risks. Innocent bystanders or communities that are not party to the activities generating burdens should not be subject to such burdens (Adeola, 688). Environmental injustices involve a systematic exclusion of minority groups in vital environmental policies and decisions. Environmental justice is the movement that links environmental degradation with social justice in a fight for sustainable human rights.
Ethical issues of justice arise when people, communities, or regions are subjected to greater environmental risk than others in a process that benefits the others. Environmental problems tend to bear down disproportionately upon poor communities because most environmental pollution and degradation is caused by the actions of the wealthy nations plagued with overconsumption habits. These affluent nations or societies, however, tend to have higher environmental quality because their environmental burden is created or exported elsewhere. Minority populations are then forced, through their lack of access to decision-making and policy-making processes, to live with a disproportionate share of environmental “bads.” “The global trends of industrialization, economic expansion, and globalization that rest on the increased exploitation of natural resources have mostly been at the expense of communal groups. Their natural resources and physical labor are being absorbed into national and international webs of economic activity” (Adeola, 688).
Environmental justice began in the United States seeking both political change and societal structure change. It is often referred to as environmental racism due to its origins with human rights violations. It was the discriminatory location of toxic waste facilities, particularly in minority areas, that triggered the formal emergence of the movement back in the early 1980s. Low-income communities and communities of color across the country, including Latinos, African Americans, Asian Americans, and Native Americas, concluded that unequal social, economic, and political power relationships made them more vulnerable to health and environmental threats than the society at large. The environmental justice movement began with the focus on waste issues, but dimensions have since expanded.
The right to a safe environment has been advocated as an essential aspect of fundamental human rights. Therefore, a disproportionate environmental burden constitutes a violation of basic human rights. We often hear the expression “NIMBY” (Not In My Back Yard). However, if we claim something is worthy of a NIMBY status, why do we allow this hazard in someone else’s back yard? Hazardous waste and polluting industries that degrade our environment should be worthy of a status not deemed for anyone’s back yard.
“A sustainable society must also be a just society, locally, nationally, and internationally, both within and between generations and species” (Agyeman, 3). Creating a sustainable society involves much more than a few days of carpooling and composting. However to construct a society we deem sustainable, than we must consider our actions outside of our direct interactions. We must be more conscious of where our products come from, where they end up, and whom they may be harming during these processes. As Colgate students we are educated and aware of global issues such as environmental justice so we must be cognizant of how our actions affect others. Because we are so far removed from all the polluting processes, the health of environment and laborers is easy to disregard. However, if we choose to be conscious consumers and dig a little deeper, then we can uncover some disconcerting facts about our consumer society and the environmental injustices it causes. The next time you are thinking about purchasing the newest iPhone, think about where the materials to create it come from and where your current phone will be going. The next time you want to order that shirt you saw online, think about how it was made and by whom. The next time you go grocery shopping, think about how your food was grown and how far it will be traveling to get to your plate. It’s time we start thinking about what we can do to become a sustainable society and help correct our injustices along the way.
Adeola, Francis O. “Cross-National Environmental Injustice and Human Rights Issues: A Review of Evidence in the Developing World.” The American Behavioral Scientist 43.4 (2000): 686-706. Print.
Agyeman, Julian, Robert D. Bullard, and Bob Evans. Just Sustainabilities: Development in an Unequal World. London: Earthscan Publi | <urn:uuid:3fcad5b9-1e13-4114-a98b-1132368b0ff6> | CC-MAIN-2016-26 | http://blogs.colgate.edu/sustainability/2014/04/23/what-is-environmental-justice-and-why-should-we-care/ | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783393332.57/warc/CC-MAIN-20160624154953-00126-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.943682 | 952 | 4.0625 | 4 |
The Carbon Cycle
Plants and other producers extract this gaseous carbon and, using energy from the sun, convert it into sugar. Producers and consumers alike use this sugar form of carbon as a source of energy and as a source of raw material for growth. As carbon moves through the food chain, much of it is released back into the atmosphere as CO2 when consumers exhale. Whatever is not exhaled eventually accumulates in the ground when organisms die and decompose. Once carbon is in the ground, it leaves the carbon cycle forever. The exception to this is when humans extract it in the form of oil, coal, and natural gas, and release it back into the atmosphere by burning it. The endpoint here is that without carbon, producers would not have any way to use energy from the sun. In fact, life as we know it wouldn’t exist at all. And that would suck just a little bit.
You've probably heard that CO2 is a serious greenhouse gas, but methane, CH4, is 20 times as potent. Methane is produced naturally by a group of microbes called methanogens. These microbes live deep in anoxic sediments, associated with plants, and also, yes, in cows. The average cow releases somewhere between 500-600 liters of methane into the air per day! Holy cow! | <urn:uuid:56d0b850-4bbc-4d55-a360-fb14242b38d1> | CC-MAIN-2016-26 | http://www.shmoop.com/ecology/carbon-cycle.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783397636.15/warc/CC-MAIN-20160624154957-00110-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.959766 | 274 | 3.703125 | 4 |
Standardized tests are championed as a way to ensure greater accountability in education. But for many teachers and school administrators, so-called "high-stakes" testing regimes also provide strong incentive to cheat and can reward dishonesty.
This trend is evident across the country. One recent example is an emerging case involving Arizona’s Sunnyside School District. According to a recent article, a math coach working for the district alleges that district teachers might have been, and be, helping first- and second-graders cheat on exams. According to the math coach, Jean Olson, some of the curiosities with regards to the test in question include a high incidence of erasures (i.e. wrong answers changed to correct answers; nearly half of the relevant 400 tests had erasures) and an unusual increase in the combined scores across seven classes over a nine week period.
The exams in question, known as “Standardized Bench Mark Assessments,” are given by school districts periodically in order to track student progress. Benchmark tests categorize results based on the same categories mandated by the No Child Left Behind Act—which include socio-economic standing and race—and these results are then often reported to the local or state districts in order to compare academic standings, percentiles, and general educational improvement.
After lodging her complaint, Olson was not rehired for the following school year. The article cited above reports on Olson’s hearing; however, according to the hearing officer, the “scope of his inquiry did not touch on whether cheating occurred” but rather the “technicalities” of Olson’s complaint. No teachers have been found guilty of cheating on the benchmark tests. In fact, there has been no formal charge brought against them. The only measure taken by the district to assess whether or not teachers had allowed and even encouraged cheating was to simply ask the teachers involved if they had encouraged cheating or changed students' answers. Unsurprisingly, the teachers said: no. This rigorous inquiry was grounds for the continuation of business-as-usual in Sunnyside School District.
Why might the school district be hesitant to launch a full-blown investigation of specious test results? Well, under current federal and state laws, improved test scores mean the allocation of more funding and resources, which gives educators incentive to pad scores. A current law in Arizona bases twenty percent of a superintendent’s salary and benefits package on student body performance. This is not uncommon. A similar law in Georgia is the source of huge controversy and is clearly linked to a major teacher cheating case in Atlanta. The Atlanta case is only one example of how this kind of law can lead to widespread corruption among teachers, administrators, and entire school districts. Poor school districts, populated by students who make the least progress, may be the most susceptible to teacher cheating scandals.
Strong metrics are important for reforming public education and standardized tests are one key metric. But the profit-for-progress structure creates a highly-competitive or even cut-throat approach to public education and incentivizes unethical behavior.
When teachers start to cheat, how much hope can we have for the ethics of our children? | <urn:uuid:3aa20f83-a4bf-48e7-9625-fe0674e28951> | CC-MAIN-2016-26 | http://www.cheatingculture.com/teacher-cheating/2010/11/24/teacher-cheating-spreads-along-with-high-stakes-tests.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783392099.27/warc/CC-MAIN-20160624154952-00152-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.959794 | 651 | 2.90625 | 3 |
Chemistry in its element: compounds
MP3 Download (3316k)
From bleached blonde hair to rocket fuel, hydrogen peroxide always gets an explosive reaction from Brian Clegg
Introducing Chemistry in its element series two: distilling the compounds that count. Each week a leading scientist or author tells the story behind a different compound
Chemistry in its element - hydrogen peroxide
Distilling the compounds that count, you're listening to Chemistry in its element brought to you by Chemistry World magazine
This week, the chemistry behind the bleached blonde. Not bleached himself, here's Brian Clegg.
There are few compounds that have names that can produce an emotional reaction. Yet mention peroxide - the common contraction of hydrogen peroxide - and a whole host of images come to mind, mostly involving the bleached blonde hair of 1930s movie stars like Jean Harlow and a slightly seedy glamour.
In fact this association goes back further than the 1930s. Consider this wry comment from one H Rowland in 1909: 'Men say they hate anything loud about a woman; it must be disgust that makes them always turn around to stare after a peroxide blonde.' The earliest references are not derogatory. But by 1903, the New York Times carried the comment 'I hate girls who make up. and most of these blondes are peroxides.' The peroxide blonde was becoming someone dangerous to know.
All these associations are embodied in a compound that is almost but not quite water. Originally a peroxide was just any compound of an element with oxygen that contained as much oxygen as possible, but it has come to mean a molecule with a pair of oxygen atoms bonded together - in the case of hydrogen peroxide simply H2O2 - water with an added oxygen atom.
We usually encounter hydrogen peroxide diluted with water, where it is pretty well colourless and visually difficult to distinguish. A typical consumer bottle of hydrogen peroxide may be as low as 3 per cent peroxide by weight. As well as bleaching hair (and other materials) its powerful oxidising qualities make hydrogen peroxide in demand for everything from disinfectant to rocket fuel.
Although existing widely in nature, forming part of the respiration process of cells, hydrogen peroxide came relatively late to the chemical toolkit, first produced in 1818 by French chemist Louis Jacques Thénard, but not definitely structurally identified until the end of the century, by which time it had already found its way into the hands of hairdressers.
The immediate association we have for peroxide is removing colour from hair until it reaches that impossibly white blonde, but its biggest industrial use by far is in bleaching paper. As a bleach it is more powerful than chorine-based alternatives, with the added benefit of only producing water and oxygen from its reaction. We are so familiar with bleach as a disinfectant or as a stain remover that it's easy to forget that a bleach is just another word for an oxidiser, a compound that easily donates oxygen (or accepts electrons) in a reaction.
When hydrogen peroxide is used to produce those bleached blondes, a dilute solution is typically combined with ammonium hydroxide (in the household sense usually referred to simply as 'ammonia'), although modern hair dyes often replace ammonia with alternatives because of its pungent odour.
It is a bit of a leap from a hairdresser's salon to Mission Control, but the most dramatic use of hydrogen peroxide is as a rocket propellant. In small devices - most frequently in jet packs, which have appeared in James Bond movies but never proved particularly practical - the hydrogen peroxide can be used on its own. At high concentrations it only takes a catalyst like platinum to kick hydrogen peroxide into breaking down into water and oxygen. The heat from the reaction means that the water is expelled as a violent jet of steam. Unfortunately, to produce enough thrust to lift a human being, the jet pack can only fly for under a minute.
In larger rockets, including some of the German second world war missiles and the Black Knight weapons produced in the UK, hydrogen peroxide acts as an oxidiser for a separate fuel, providing the oxygen for it to burn efficiently. The same role has tended to be given to liquid oxygen in Nasa spacecraft. But though hydrogen peroxide isn't as good an oxidizer, it is significantly easier to store and handle. It also formed the oxidiser for the explosives used in the 7th of July bombings in London in 2005.
The explosive and propellant capabilities of hydrogen peroxide may be what makes the headlines, but it is its role as a humble bleach, antiseptic and disinfectant - plus an ingredient in the production of sodium percarbonate and sodium perborate for washing powders - that keeps hydrogen peroxide in steady production.
As a young amateur chemist I several times had a drop of hydrogen peroxide solution end up on my hands. I wouldn't recommend it, but it is a fascinating feeling. The liquid penetrates the skin and produces a whitening effect as it causes tiny embolisms in the capillaries. Meanwhile, the oxygen bubbling off as the peroxide reacts leaves a strange tingling sensation, a vibrant bubbling under the skin. It might be impossible for hydrogen peroxide to shake off its slightly sinful associations - yet this ever-useful oxidiser can't help but be bubbly too.
Bubbly yet sinful - quite a combination. That was Brian Clegg with the explosive and propelling chemistry of our hydrogen peroxide. Now next week, the skillful plant.
Plants do have one problem, though; they can't run, so they are the mercy of predators, like insects, bacteria and fungi. Secondary metabolites are the plants' answer to this, compounds that stop them being eaten.
The South American coca plant, which is native to the Andes, makes a molecule called benzoylmethylecgonine, but you might know it as cocaine, coke, snow, or any of a multitude of names. The coca plant makes cocaine from the amino acids orthinine and glutamine; it is a skilled synthetic chemist, because the cocaine molecule has 4 chiral centres, but only one of the 16 possible isomers is made by the coca plant.
And to find out how the coca plant has been used throughout history - both for purpose and recreation - as well as the chemistry behind its effects, join Simon Cotton in next week's Chemistry in its element. Until then, thank you for listening. I'm Meera Senthilingam
Chemistry in its element comes to you from Chemistry World, the magazine of the Royal Society of Chemistry and is produced by thenakedscientists dot com. There are more compounds that count on our website at chemistryworld dot org slash compounds. | <urn:uuid:cc0c5bdf-d5d2-465e-a454-052c0efaa90d> | CC-MAIN-2016-26 | http://www.rsc.org/chemistryworld/podcast/CIIEcompounds/transcripts/H2O2.asp | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783396945.81/warc/CC-MAIN-20160624154956-00145-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.957444 | 1,413 | 2.96875 | 3 |
Feeling a little meteor-starved lately? Me too. It’s been a meteor shower desert since the Quadrantids of early January. That’s about to change. This weekend brings the celestial version of April showers with the annual appearance of the Lyrids.
The Lyrids ding the bell at maximum strength this weekend April 21-22 (Sunday night-Monday morning in the Americas) hurtling meteors at the modest rate of 10-20 per hour from a point in the sky not far from bright Vega in the constellation Lyra. While some showers spread their meteor crumbs over several days, the Lyrids’ peak activity lasts less than a day. The western hemisphere – particularly the western half of North America – is favored this year.
There will be a small price to pay for the show. The Lyrid radiant, the point in the sky from which the showers members radiate, rises in the east rather late – around 10:30 p.m. local time. Then there’s the bright gibbous moon, which has a habit of drowning out fainter stars and meteors alike. That makes the best time for viewing the shower after moonset or around 4 a.m. Monday morning. Since dawn begins about 5, you’ll have one good hour. That’s plenty of time to snag at least a few flaming motes of Comet Thatcher.
Like most meteor showers, the Lyrids have a parent and single parents are the rule. For the Lyrids, it’s Comet Thatcher, discovered on April 5, 1861, a week before the start of the Civil War, by amateur astronomer A.E. Thatcher observing from New York City. Later it was found to be linked to the Lyrid meteor shower.
Each year in late April, Earth passes through centuries of dust shed by the comet’s tail. When bits of Thatcher flotsam strike the air some 60-70 miles high, they burn up in flashes of meteoric light. Comet tears.
All meteors are worthy of keeping an eye on, but bear in mind that the Lyrids are no Perseids, the famed summertime shower offering up to 60 meteors per hour under dark skies. But what they lack in numbers, they make up in reliability and surprise.
Records indicate that people have been watching the Lyrids for at least 2,600 years, the longest of any shower. Our oldest descriptions come from the Chinese who penned that “stars fell like rain” on March 16, 687 BC. Apparently the shower was more active in the past and has since evolved into a minor display. But there have been occasional surprises, and that’s what keeps the Lyrids interesting.
On April 20, 1803 a fire bell roused Richmond, Virginia residents from their beds to witness a similar rain of stars when up to 700 meteors per hour were seen. Other Lyrid outbursts occurred in 1922 (100 per hour), 1945 (100/hr), 1982 (90/hour). Last year’s peak hit 37 per hour from a dark sky site. Now and then, Earth encounters a thicker band of comet debris left behind by Comet Thatcher, suddenly increasing the meteor count by many times and just as suddenly dropping back to the usual 10-20 per hour.
So here’s the bottom line. Don’t expect a big blast, but do avail yourself of the leisurely pleasure of meteor watching and the possibility of seeing pieces of a comet that rounds the sun only every 415 years. Find a spot where artificial lights is at a minimum, dress warmly and head out around 3:30 a.m. Monday. Set up a comfortable lawn chair and have tea or coffee and a blanket at the ready. You’ll do well to face south or east. Now recline back to allow a fulsome view of the sky above and wait for a few well-deserved ooohs and aaahs. | <urn:uuid:c53d09a7-abfe-4caa-8081-9e9dce3da143> | CC-MAIN-2016-26 | http://myscienceacademy.org/2013/04/19/this-weekends-lyrid-meteor-shower-how-to-see-it/ | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783404382.73/warc/CC-MAIN-20160624155004-00095-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.934522 | 834 | 2.53125 | 3 |
Metacognition And Learning: Strategies For Instructional Design. Sharebar Do you know how to learn?
Many people don’t. Specifically, they don’t know how to look inward to examine how they learn and to judge what is effective. That’s where metacognitive strategies come in. They are techniques that help people become more successful learners. Improved metacognition can facilitate both formal and informal learning. But let’s start at the beginning. What is metacognition? Metacognition is often referred to as “thinking about thinking.” The Two Processes of Metacognition Fortunately, many theorists organize the skills of metacognition into two components.
Metacognition and Expertise Many experts cannot explain the skills they use to elicit expert performance. Examples of Metacognition Skills You May Use Successful learners typically use metacognitive strategies whenever they learn. Metacognitive Strategies Metacognitive strategies facilitate learning how to learn.
Ask Questions. References: Hacker, Douglas J., John Dunlosky and Arthur C. Learning Development and Innovation Publications & Reports.
The Science of Learning: Best Approaches for Your Brain. Do you wonder why people don’t understand the idea you’re trying to get across in a meeting?
Are you mentoring another developer and struggling to understand why the still don’t get it? Do you run training courses and wonder why the attendees only learn 10% of the material? We are all teachers whether as informal mentors, coaches, trainers or parents. Yet only professional educators receive training in this area. Nearly two years ago I started reading neuroscience (Norman Doidge’s “The Brain that Changes Itself”), for fun. Only twenty years ago most people in the world of neuroscience believed that the connections between the neurons in your brain were fixed by the time you were a teenager (or even younger). The hippocampus is the gatekeeper for long term memory, in this case declarative memory (i.e. stories and experiences).
Abstract Ideas We sometimes start talking about Unit Testing with a long theoretical explanation and we get blank stares from the people we’re trying to help. 50 Brain Facts Every Educator Should Know. January 27th, 2010 By Pamelia Brown The brain is perhaps the most fascinating organ in the human body. It controls everything from breathing to emotions to learning. If you work with children, here are some facts that you might find helpful, from how the brain affects learning to facts about memory to interesting facts about the brain that you can share with your students.
Brain Development and Learning Read on to learn interesting facts about how the brain develops, what can affect that development, and how learning is impacted. Read aloud. Memory Learn about the way short-term memory differs from long-term memory, how scent affects memory, and more. Different types of memory. Brain Trivia From how the brain helps while blinking to early brain surgery, these bits of trivia might come in handy the next time you are teaching about the brain. Blinking. Unconscious learning uses old parts of the brain. Public release date: 6-Apr-2010 [ Print | E-mail Share ] [ Close Window ] Contact: Katarina [email protected] 46-852-483-895Karolinska Institutet A new study from the Swedish medical university Karolinska Institutet provides evidence that basic human learning systems use areas of the brain that also exist in the most primitive vertebrates, such as certain fish, reptiles and amphibians.
The study involved an investigation into the limbic striatum, one of the evolutionarily oldest parts of the brain, and the ability to learn movements, consciously and unconsciously, through repetition. "Our results strongly substantiate the theories that say that the implicit, by which I mean non-conscious, learning systems of the brain are simpler and evolutionarily older," says Associate Professor Fredrik Ullén from Karolinska Institutet and the Stockholm Brain Institute. Download press images: For further information, contact: [ Print | E-mail. | <urn:uuid:66807c45-cd67-4d77-83b5-9450ea004322> | CC-MAIN-2016-26 | http://www.pearltrees.com/mattao/cerveau-apprentissage/id3341205 | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783398216.41/warc/CC-MAIN-20160624154958-00198-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.926831 | 861 | 3.15625 | 3 |
Question: What is the difference between Cubic Feet per Second (CFS), Gallons per Minute (GPM), Gallons (G), and Acre Feet (AF)?
Answer: Cubic Feet Per Second (CFS) and Gallons Per Minute (GPM) are both ways of expressing instantaneous rate of diversion. Gallons (G), or Acre Feet (AF) describe volume of water applied to land, stored in reservoirs, or consumed in a time period, such as a month.
Water use quantities need to be reported as monthly volumes, rather than as rates of diversion.
To find the volume of water diverted in a month, multiply the instantaneous rate times the amount of time that diversion occurred during the month. Examples:
· Diverting at 10 GPM, for 8 hours a day for 10 days in a month = 10 gallons per minute x 60 minutes per hour x 8 hours per day x 10 days = 48,000 gallons for the month.
· Diverting at 2.5 CFS, for 12 hours per day, 5 days per month = 2.5 cubic feet per second x 60 seconds per minute x 60 minutes per hour x 12 hours per day x 5 days = 540,000 cubic feet for the month.
You may report your monthly usage as any one of the following: Acre Feet (AF), Gallons (G), Thousand Gallons (KG), Million Gallons (MG), Cubic Feet (CF), or Million Cubic Feet (MCF).
Regardless of the unit of measurement originally reported, for comparison purposes, the Department converts all water use quantities to AF. One Acre Foot is the volume of water that will cover an acre of ground one foot deep.
Some conversion factors:
1 cubic foot (CF) = 7.48 Gallons
1 CFS = 448.8 gallons per minute (GPM)
1 Acre Foot (AF) = 325,851 Gallons (G)
1 Acre Foot (AF) = 43,560 Cubic Feet (CF)
For continuous 24-hrs per day diversions: (CFS) x (1.98) x (# of days used per month) = AF per month | <urn:uuid:0aeaa3d2-3c41-4bca-8709-d3239fdc0ad2> | CC-MAIN-2016-26 | http://www.oregon.gov/owrd/Pages/WR/FAQ.aspx | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783393533.44/warc/CC-MAIN-20160624154953-00147-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.802184 | 456 | 3.375 | 3 |
RNAi can change genetically based behaviors like sex drive. (from technology review) The study used a method that overcomes two key problems of delivering RNAi directly: the difficulty of getting RNA into cells and its transitory effect. The researchers used an altered virus, which can easily infect cells but does not cause a dangerous immune response, to deliver DNA sequences from the ER-alpha gene to cells. When the gene is turned into RNA, the molecule folds in half and the two complementary sides zip together, joined by a tiny hairpin loop that's snipped by proteins in the cell, creating a short double-stranded RNA. When delivered by virus, the small hairpin RNA, or shRNA, is produced indefinitely in cells. The treatment must be delivered surgically in order to reach a precise location. | <urn:uuid:064a611a-ea2f-4880-a6b7-f880f7d38993> | CC-MAIN-2016-26 | http://nextbigfuture.com/2006/06/rnai-can-get-into-cells-and-have.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783395621.98/warc/CC-MAIN-20160624154955-00066-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.959937 | 163 | 3.234375 | 3 |
E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Monophysites (4 syl.).
A religious sect in the Levant, who maintained that Jesus Christ had only one nature, and that divine and human were combined in much the same way as the body and soul in man. (Greek, monos phusis, one nature.) | <urn:uuid:bb1ae857-d096-40e9-8f24-e31a9274eb61> | CC-MAIN-2016-26 | http://www.bartleby.com/81/11592.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783396887.54/warc/CC-MAIN-20160624154956-00136-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.953687 | 79 | 2.765625 | 3 |
10. What writers of the Bible refer to Job and what is their estimate?
11. Read Chapter 38 and write out your impressions of it in concise statements, using fifty words.
12. Give three general reasons why the narrative of Job is to be received as an historical fact.
THE KINGDOM FORMING
I. Pictorial Device.
Originate one, or omit.
V. 1706 B.C. to 1490 B.C., making 216 years.
VI. 1. 1 to 18. Israel Delivered.
2. 19 to 34. Israel Taught at Mount Sinai.
3. 35 to 40. Israel Prepared for Worship.
VII. Chapter 20.2.
VIII. God Delivering a Nation.
IX. 12:13: “And when I see the blood I will pass over you.”
X. 1. Bondage.
3. Burning Bush.
14. Red Sea.
25 and 35. The Tabernacle.
XI. Select five.
XII. 1. God gives deliverance to the oppressed.
2. God assumes authority over the actions of men.
3. God desires to dwell in the midst of His people.
XIII. (a) Symbol: 1. Passover Lamb. 1 Cor. 5:7. Note three or four likenesses between the lamb and Christ.
2. Manna. John 6:35.
3. Rock. I Cor. 10:4.
4. Tabernacle. Hebrews 9:11. John 1:14, marginal reading.
(b) Type. None.
(c) Analogy. None.
(d) Prophecy. None.
NOTES AND SUGGESTIONS
Under No. 5 fail not to compare length of time covered by different books. Under No. 7 ask pupils to show the appropriateness. Under No. 9 teacher may require committal of location or not, as is deemed advisable. Under No. 12 show the truth of these universal lessons through the march of history. Under No. 13 copy the references, be able to explain their meaning, and to show the likeness between the symbol, the type, and Christ. In copying this outline work the pupil may or may not omit the names of the fourteen topics, according to the teacher’s judgment. For the inspection of friends it would be preferable to have the words of these topics repeated with each outline, as in Genesis. As an aid to concert recitation let the teacher place the topics of the outline upon the blackboard and repeat names and answers together. | <urn:uuid:f33d3d99-5adc-42da-8d1b-afc73dab5d2a> | CC-MAIN-2016-26 | http://www.bookrags.com/ebooks/16461/11.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783395620.9/warc/CC-MAIN-20160624154955-00088-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.872527 | 547 | 3.5 | 4 |
Resources and guidance for teachers
The Institute’s suite of teaching resources.
Girls in the Physics Classroom: A teachers’ guide for action is a guide for teachers on how to put the research findings into action.
Engaging with Girls: An action pack for teachers includes guidance on carrying out action research and a set of additional teaching resources.
Science: It’s a people thing is a pack of resources for running an off-timetable discussion workshop with female students.
The girls in physics videos illustrate teaching approaches that the research suggests will encourage girls to consider continuing with the subject. | <urn:uuid:263ccbf7-f553-43f8-9a15-e063fd8f52dc> | CC-MAIN-2016-26 | http://www.iop.org/education/teacher/support/girls_physics/resources-and-guidance-for-teachers/page_63821.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783397873.63/warc/CC-MAIN-20160624154957-00141-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.912085 | 124 | 3.59375 | 4 |
Crowds of people came out to the stations to meet us, and black and white, old and young, all joined in the heartiest demonstrations of welcome. Were also greeted from the houses and roadsides all along the line by people waving their handkerchiefs and swinging their hats. At Mechanicsburg a whole girls' school was out to see us. This was a specially engaging sight to some of our number, who thought that that village would be a good place to camp. The elite of the town were at the station, and S. pointed out to me the leading beauties of the place - I mean the ladies. Soldiers of a day, we already began, in the midst of these inspiring scenes, to feel like real veterans.
|An Illustrated History of the Commonwealth of Pennsylvania|
Founded in 1856, the Irving Female College was named for famed author Washington Irving, who served on the board of trustees until his death in 1859. It became the first female college in the nation to grant degrees in arts and science. Irving Hall, a large Italianate building, was soon constructed, "amongst a beautiful grove and grounds" located along the Cumberland Valley Railroad tracks, and on the eastern end of town (an area soon known as Irvington). Irving Hall could house "forty students, as well as supply the classroom, the parlor, the library, and the college offices." In the early days of the school, the average enrollment was 91 students (many of which were day students who lived in the surrounding region).
By the end of the 19th Century, the College was prospering; a second building was needed. Known as Columbian Hall, the new building, "contained 40 additional dormitory rooms on the upper floors and a large auditorium on the first floor." In 1901, an expanded wing was constructed onto the eastern wing of Irving Hall, creating rooms for music, a kitchen, a cafeteria, and a gymnasium. In it's hey-day, Irving Female College had buildings that were, "...imposing in appearance, substantially built of brick, conveniently arranged, and comfortably fitted up with the modern conveniences, and every thing calculated to make it an attractive and safe home, with full and thorough educational advantages for young ladies." Some of Irving's "young ladies" would go on to be accomplished alumnae, including Ida Kast, Cumberland County's first female attorney, and Jane Deeter Ripon, President of the Girl Scouts of America.
|postcard of Irving Female College ca. 1901. Columbian Hall is located on the right.|
|postcard of Irving Female College ca. 1901. Expansion can be seen at left-rear of Irving Hall.|
The presence of Irving was not just enjoyed by the young men of the Emergency Militia, but by the town itself, as it, "...provided Mechanicsburg with a source of culture, music, great literature and drama that the rural town would not have experienced otherwise." An alumna later said "The college meant a great deal to the community. It was a social center."
|President's Hall ca. 1982 (built 1911, since demolished)|
|Irving Hall as seen today - Dave Maher|
Egle, M.D., William H. An Illustrated History of the Commonwealth of Pennsylvania, Civil, Political, and Military, From it's Earliest Settlement to the Present Time, Including Historical Descriptions of Each County in the State, Their Towns, and Industrial Resources. Harrisburg, PA: De Witt C. Goodrich & Co., 1876.
Richards, Louis. Eleven Days in the Militia During the War of the Rebellion; Being a Journal of the "Emergency" Campaign of 1862. Philadelphia: Collins, Printer, 1883.
Rose, Sarah, "Irving Female College National Register of Historic Places nomination form", 1982. on file at the Pennsylvania State Historic Preservation Office, or online through the Cultural Resource GIS. | <urn:uuid:f481370b-efeb-4b62-a978-727e547161c2> | CC-MAIN-2016-26 | http://paemergencymen.blogspot.com/2012_03_01_archive.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783404405.88/warc/CC-MAIN-20160624155004-00024-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.972328 | 814 | 2.734375 | 3 |
Spear Thistle (Cirsium vulgare) family Asteraceae
It is a tall biennial or short-lived monocarpic thistle, forming a rosette of leaves and a taproot up to 70 cm long in the first year, and a flowering stem 1–1.5 m tall in the second (rarely third or fourth) year. The stem is winged, with numerous longitudinal spine-tipped wings along its full length. The leaves are stoutly spined, grey-green, deeply lobed; the basal leaves up to 15–25 cm long, with smaller leaves on the upper part of the flower stem; the leaf lobes are spear-shaped (from which the English name derives). The inflorescence is 2.5–5 cm diameter, pink-purple, with all the florets of similar form (no division into disc and ray florets). The seeds are 5 mm long, with a downy pappus, which assists in wind dispersal. As in other species of Cirsium (but unlike species in the related genus Carduus), the pappus hairs are feathery with fine side hairs.
Spear Thistle is often a ruderal species, colonising bare disturbed ground, but also persists well on heavily grazed land as it is unpalatable to most grazing animals. The flowers are a rich nectar source used by numerous pollinating insects, including Honey bees, Wool-carder bees, and many butterflies. The seeds are eaten by Goldfinches, Linnets and Greenfinches.
The seeds are dispersed by wind, mud, water, and possibly also by ants; they do not show significant long-term dormancy, most germinating soon after dispersal and only a few lasting up to four years in the soil seed bank. Seed is also often spread by human activity such as hay bales.
Spear Thistle is designated an "injurious weed" under the UK Weeds Act 1959, and a noxious weed in Australia and in nine US states. Spread is only by seed, not by root fragments as in the related Creeping Thistle C. arvense. It is best cleared from land by hoeing and deep cutting of the taproot before seeds mature; regular cultivation also prevents its establishment.
The stems can be peeled and then steamed or boiled. The tap roots can be eaten raw or cooked, but only on young thistles that have not flowered yet.
Information supplied by: | <urn:uuid:d462d8dc-4b1d-418c-b569-f1d5c062cc41> | CC-MAIN-2016-26 | http://saphotographs.blogspot.com/2012/01/spearthistle-cirsium-vulgare.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783395546.12/warc/CC-MAIN-20160624154955-00153-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.952696 | 522 | 3.4375 | 3 |
Definition of Carotenoid
Carotenoid: One of a group of compounds that includes beta-carotene, alpha-carotene, and beta-cryptoxanthin which are converted to vitamin A and are referred to as provitamin A carotenoids. The sole known role of carotenoids is to act as a source of vitamin A in the diet. Fruits and vegetables are the main source of carotenoids in the human diet.Source: MedTerms™ Medical Dictionary
Last Editorial Review: 6/14/2012
Weight Loss Wisdom
Get tips, recipes and inspiration. | <urn:uuid:010f719b-0633-4247-b7f1-e31ad4e18d6c> | CC-MAIN-2016-26 | http://www.rxlist.com/script/main/art.asp?articlekey=22370 | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783404382.73/warc/CC-MAIN-20160624155004-00028-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.901084 | 128 | 3.53125 | 4 |
Being Bilingual 'Boosts Brain Power'
Learning a second language can boost brain power, scientists believe.
The US researchers from Northwestern University say bilingualism is a form of brain training - a mental 'work out' that fine-tunes the mind.
Speaking two languages profoundly affects the brain and changes how the nervous system responds to sound, lab tests revealed.
Experts say the work in Proceedings of the National Academy of Sciences provides 'biological' evidence of this.
For the study, the team monitored the brain responses of 48 healthy student volunteers - which included 23 who were bilingual - to different sounds.
They used scalp electrodes to trace the pattern of brainwaves.
Under quiet, laboratory conditions, both groups - the bilingual and the English-only-speaking students - responded similarly.
But against a backdrop of noisy chatter, the bilingual group were far superior at processing sounds.
They were better able to tune in to the important information - the speaker's voice - and block out other distracting noises - the background chatter.
And these differences were visible in the brain. The bilingualists' brainstem responses were heightened.
Prof Nina Kraus, who led the research, said: 'The bilingual's enhanced experience with sound results in an auditory system that is highly efficient, flexible and focused in its automatic sound processing, especially in challenging or novel listening conditions.'
Co-author Viorica Marian said: 'People do crossword puzzles and other activities to keep their minds sharp. But the advantages we've discovered in dual language speakers come automatically simply from knowing and using two languages.
'It seems that the benefits of bilingualism are particularly powerful and broad, and include attention, inhibition and encoding of sound.'
Musicians appear to gain a similar benefit when rehearsing, say the researchers.
Past research has also suggested that being bilingual might help ward off dementia. - BBC | <urn:uuid:6ce5485e-85a3-4f96-9f50-0c01bd3ec459> | CC-MAIN-2016-26 | http://www.modernghana.com/news/392811/1/being-bilingual-039boosts-brain-power039.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783396875.58/warc/CC-MAIN-20160624154956-00189-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.931718 | 383 | 3.40625 | 3 |
TUESDAY, March 12 (HealthDay News) -- As roller-derby skaters bump and smack one another on the track, a new study finds that they're exchanging more than bruises: These combative women are also swapping countless bacteria that live on their skin.
Researchers who analyzed skin samples were able to distinguish among teams by the bacteria on the skaters' skin, and they could track how the bacteria moved between teams during a bout.
"The thing that was surprising was how different the teams' different bacteria were before they played, and how similar they became afterward," said study author James Meadow, a postdoctoral research associate at the University of Oregon in Eugene.
Germs pass from person to person, from people to things and from people to animals all day long, he said, but it's usually harmless. "We pick them up from the environment, and we give them off to the environment," he said. "This study was a way to find out how that changes when we come into contact with other people."
For the study, published in the March 12 issue of the new journal PeerJ, researchers studied three roller-derby teams competing in a tournament: the Emerald City Roller Girls from Eugene, Ore.; the DC Roller Girls from Washington, D.C.; and the Silicon Valley Roller Girls from San Jose, Calif.
To obtain microbe samples, the researchers swabbed the skaters' upper arms, which are typically exposed before, during and after a game.
Each team's members had very similar bacteria, possibly because their players came from the same geographical places. "If we picked one of the players at random, I could tell you which team she played for," Meadow said.
But the bacterial makeup of the skin on their arms changed after skin-to-skin contact with other skaters. "It was difficult to tell the teams apart. They had mixed a lot of their skin bacteria," Meadow said.
Athletes can and do transmit potentially dangerous skin infections to one another, but it's not clear if the germs transmitted between these players could have made them sick, the researcher said. When it comes to the sharing of germs, Meadow said, "we don't know what impact that has or how long it lasts."
Nor is it clear exactly how many bacteria transferred among skaters as they collided and fought for track position in this heavy-duty contact sport.
Still, skin infections are nothing to dismiss. A "superbug" called methicillin-resistant Staphylococcus aureus (MRSA) can be transmitted between athletes on a football field and even through shared towels. MRSA is sometimes fatal.
What about other kinds of human contact, such as handshakes, kissing and sex? The risk of body-to-body bacteria transmission from those activities is another mystery, although it's known that the skin, mouth and vagina are home to unique communities of germs, Meadow said.
"The transmission could be at this level or more," he said, referring to the study findings. "One thing we can say for certain is that we're transferring things in all types of human contact" -- derby or no derby.
Dr. Pascal James Imperato, dean of the School of Public Health at SUNY Downstate Medical Center in New York City, said the study demonstrates how people from the same areas have similar kinds of bacteria on their skin.
Should people worry about touching each other?
Not generally, Imperato said. "There's no reason anyone should institute any kind of preventive measures because the majority of these bacteria are not pathogenic," he said. "They're garden-variety bacteria found on the skin of ordinary people. I don't think it's anything to worry about."
For more about skin infections, try the U.S. National Library of Medicine.
SOURCES: James Meadow, Ph.D., post-doctoral research associate, University of Oregon, Eugene; Pascal James Imperato, M.D., dean, School of Public Health, SUNY Downstate Medical Center, New York City; March 12, 2013, PeerJ
All rights reserved | <urn:uuid:afbd179c-a289-4b40-868f-5e29fbf42b11> | CC-MAIN-2016-26 | http://www.bio-medicine.org/medicine-news-1/Germs-Fly-in-Roller-Derby-Games--Study-Finds-101738-1/ | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783395160.19/warc/CC-MAIN-20160624154955-00181-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.974802 | 852 | 2.71875 | 3 |
Q. We have an older bittersweet that badly needs to be trimmed back. When should I do this?
Betty Jelinek, Jackson
A. Early spring is the best time to prune bittersweet in Michigan, Betty, and your first order of priority should be to get the oldest branches pruned away. Doing so will improve fruiting.
Bittersweet is a very rapid grower so if your plant hasn't been pruned for some time, you'll likely find a tangle of vines that at first blush seems impenetrable. But it's not quite the tangled mess it seems. Instead of reducing the mass by pruning off tips of all the branches, remove entire branches, especially the oldest ones. Take them off right back to the main stem, or soil. The oldest branches will be the thickest of the bunch and will likely be the ones with the fewest leaves. Take these off first and see what's left. A rough pruning guideline is to take off no more than 20 percent of a plant's bulk at any one time and that usually means no more than 20 percent each year. Ideally, you are pruning on an annual basis to keep the plant's natural shape intact and its size within the space allocated for it. With annual pruning, you'll typically remove 5 to 10 percent.
A very over-grown bittersweet is an exception to the 20 percent guideline. Betty, if your plant is very large and tangled, then I'd prune back one third of its bulk early next spring. That should get it back within bounds and only light to moderate touch-up pruning will be needed in subsequent years.
Two other factors may explain why Betty's bittersweet hasn't set fruit.
One is sunlight. Bittersweet sets the most fruit when it gets full sun all day. Over time, low-growing plants like the bittersweet are increasingly shaded as nearby trees and shrubs grow taller and broader. So what was once a free-fruiting shrub becomes less so with each passing year. This is one of those things around the yard hat seem to take several years before it sinks in that something is not right.
The other explanation for no berries is the plant is lack of a male plant nearby. I wasn't sure about this angle, so I checked my references and learned the bittersweet is usually dioecious. A dioecious plant is one in which male and female flowers are borne on separate plants. Holly is a prime example of this. Holly berries are borne on female plants but to make that happen, there must be a male nearby. With bittersweet, it is not as clear-cut. My references say the plant is usually dioecious. So, I guess that means it may need a male nearby, or it might not.
To have a bittersweet but not to have its fruits is a shame, given the bright and welcome color berries provide through the autumn and winter. In my opinion, it's worth taking steps to correct the problem so the plant will bear fruit. Let's hope that in Betty's case, it's as easy as pruning out the dead wood. Providing more light usually means moving the plant (which can be difficult) or pruning off limbs and branches from nearby trees and shrubs, and that may be too drastic a measure to take just to get the bush to fruit. Adding another plant - a male - is easily done but requires having room for it and a nursery that offers plants of both genders. | <urn:uuid:ae5ab3a2-a611-4d0c-aaf7-014c919e5524> | CC-MAIN-2016-26 | http://blog.mlive.com/gardening/2007/08/pruning_bittersweet_1.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783402746.23/warc/CC-MAIN-20160624155002-00108-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.973217 | 724 | 2.53125 | 3 |
Those wishing a historical perspective are free to read on!
For read-mostly data structures, performance can be greatly improved by using asymmetric locking primitives that provide reduced overhead for read-side accesses in exchange for more expensive write-side accesses. One example of such a primitive is the distributed reader-writer spinlock, which allows read-side lock acquisition to take place with no expensive references to globally shared state in the common case .
This paper takes asymmetric locking to its logical extreme, permitting read-side access with no locking or synchronization operations whatsoever. Of course, this means that updates do not block reads, so that a read-side access that completes shortly after an update could return old data. However, any reading thread that starts its access after an update completes is guaranteed to see the new data. This guarantee is sufficient in many cases. In addition, data structures that track state of components external to the computer system (e.g., network connectivity or positions and velocities of physical objects) must tolerate old data because of communication delays. In other cases, old data may be flagged so that the reading threads may detect it and take explicit steps to obtain up-to-date data, if required [10, 15].
Section 3 introduces concepts underlying read-copy update. Section 4 presents an implementation of read-copy update. Section 5 compares measured read-copy update performance to that of a simple spinlock. Section 6 analytically compares read-copy update to other locking primitives. Section 7 discusses related work, and Section 8 presents summary and conclusions.
Section 3.1 gives a brief intuitive introduction to read-copy update. Section 3.2 gives rigorous definitions of several important terms. Section 3.3 expands on these definitions with examples. Section 3.4 presents examples of how read-copy update might be applied to a number of different programming environments. Section 3.5 describes several different read-copy update architectures.
Data structures in a parallel environment generally cannot be assumed to be stable unless the corresponding update disciplines are followed, for example that particular locks are held. Once these locks are released, no prior-knowledge assumptions can be made about the state of any data structures protected by those locks. Therefore, if a given thread currently holds no locks, it cannot make any prior-knowledge assumptions about any data structure that is protected by any lock. A thread that is holding no locks is said to be in a quiescent state with respect to any lock-protected data structure. Such a thread cannot actively reference or modify any data structure guarded by a lock.
The keystone of read-copy update is the ability to determine when all threads have passed through a quiescent state since a particular point in time. This information is valuable—if all threads have passed through a quiescent state during a particular time interval, they are all guaranteed to see the effects of any change made prior to the start of that interval. This guarantee allows many algorithms to be constructed using fewer locks, and, in some specialized but commonly occurring cases, using no locks whatsoever. Reducing the number of locks simplifies deadlock avoidance, reduces lock and memory contention, and decreases synchronization overhead, all of which in turn result in simpler and faster programs.
Guarded data structure: A data structure that cannot safely be accessed and/or updated without possessing the proper token, lock, or identity.
Quiescent state: A state beyond which a thread makes no assumptions based on prior knowledge of any guarded data structures. Although it is possible to consider quiescent states with respect to particular data structures, this paper will use "quiescent state" in the universal sense unless otherwise stated.
Quiescent period: A time interval during which each thread passes through at least one quiescent state. Note that any time interval that encloses a quiescent period is itself a quiescent period.
Summary of thread activity: A set of data structures that are used to identify quiescent periods.
3.3 QUIESCENT STATES AND PERIODS
Figure 1 shows the relationship between quiescent states and quiescent periods. Each row in the figure represents the sequence of states that the corresponding thread passes through, with time progressing from left to right. The double vertical bars represent quiescent states.
Figure 1: QUIESCENT STATES AND PERIODS
The area between the pair of dotted vertical lines is a quiescent period, since each thread passes through at least one quiescent state during this time. The horizontal arrows show the maximum length of time that each thread can legitimately make assumptions based on prior knowledge of state preceding the start of the quiescent period. Any prior knowledge of the state of any guarded data structure held by any of the threads at the beginning of the quiescent period must be forgotten by the end of that quiescent period.
This property of quiescent periods guarantees that any change made before the beginning of a quiescent period will be observed by all threads by the end of that quiescent period. This guarantee can be used to construct extremely low-overhead update disciplines. Furthermore, since locks are not needed on the read side, deadlock issues are in some cases avoided. The following two sections show example update disciplines based on quiescent periods.
3.3.1 LOCK-FREE LINKED-LIST ACCESS
If a thread removes all references to a given data structure, it may safely free up the memory comprising that data structure after the end of the next quiescent period. Note that threads traversing the data structure need not acquire any locks. The required synchronization is achieved implicitly through the quiescent states—the quiescent period guarantees that no threads reference the data structure. Eliminating read-side locking can greatly increase speedups in the many cases where updates are rare. This same effect can be achieved using a garbage collector (in environments possessing them), but at greater cost. This greater cost stems from the need to modify otherwise-read-only data to indicate that a reference is held.
For a concrete example, consider a singly linked list with Thread 0 updating Element B while Thread 1 is doing a lock-free traversal.
Figure 2: LIST INITIAL STATE
Suppose that Thread 0 needs to make a change to Element B that cannot be done atomically. Thread 0 cannot simply modify Element B in place, as this would interfere with Thread 1. Thread 0 instead copies Element B into a new Element B', modifies B', issues a memory-barrier operation, then points A’s next pointer to B'. This does not harm Thread 1 as long as B still points to C, and as long as Thread 0 waits until Thread 1 stops referencing B before freeing it.
Figure 3: LIST DEFERRED DELETION
Thread 1 can no longer obtain a reference to B, so Thread 0 waits for a quiescent period (see Figure 4) before deleting it. After the quiescent period, Thread 0 deletes B, as shown in Figure 5.
Figure 4: LIST AFTER QUIESCENT PERIOD
Figure 5: LIST AFTER DELETION
This idiom of updating a copy of an element while allowing concurrent reads gives "read-copy update" its name. This idiom may be easily extended to handle arbitrarily linked multi-lists.
Note that Thread 0 must use some sort of update discipline to handle concurrent updates. This update discipline can be of any sort, including explicit locking, atomic instructions, or techniques taken from wait-free synchronization . However, if only one thread is allowed to update the data, all locking may be eliminated.
3.3.2 LOCK-FREE BUFFER FLUSHING
For another example, suppose that a parallel program creates log buffers that must be flushed to disk, but only after all log records have been completed. One approach is to maintain a global lock so that only one process at a time could create log records. However, this could result in a bottleneck under heavy load. Another approach is to use a global lock only to allocate space for the log records, and then create the actual records themselves in parallel. If the creation of a log record does not involve quiescent states, a flush may be safely initiated after a quiescent period starting after the last log record has been allocated.
Consider an initially empty two-entry log buffer:
Figure 6: LOG BUFFER INITIAL STATE
If Threads 0 and 1 reserve both available slots, the situation will be as shown in Figure 7.
Both slots are occupied, and the "next" pointer is NULL. Therefore, Thread 2 must wait until Threads 0 and 1 have completed their entries, flush the log buffer, and only then reserve its slot.
Figure 7: LOG BUFFER FULLY RESERVED
Threads 0 and 1 could use explicit synchronization operations to inform Thread 2 when they have completed their log entries. However, this would result in needless synchronization operations for log buffers with large numbers of entries. Instead, Thread 2 waits to flush the buffer until the end of the next synchronization period. This guarantees that Threads 0 and 1 have completed their entries without requiring synchronization operations.
Note that a garbage collector is not an appropriate solution for this second example, because we need to write out the log buffer instead of freeing it.
3.4 QUIESCENT STATE EXAMPLES
A thread is said to be in a quiescent state any time that it is not keeping prior state for any data structure. Many applications and systems have natural universal quiescent states, which are quiescent states that apply to all data structures in the application or system.
For example, within an operating system (OS) with non-preemptive kernel threads, there is a direct mapping from "thread" to CPU. Any CPU that is in the idle loop, executing in user mode, offline (halted), or performing a context switch cannot be holding any references to any kernel data structure. Therefore, each of these four states is a universal quiescent state.
Similarly, many parallel user applications drop all references to guarded data structures while waiting for user input. Many transaction-processing systems drop all references to guarded data structures at the completion of a transaction. Interrupt-driven real-time control systems often drop all references to guarded data when running at base priority level. Reactive systems often drop all references to application-level guarded data structures upon completion of processing for a given event. Discrete-event simulation systems often drop all references to guarded simulation data structures at the end of processing for each discrete event. These applications therefore also possess natural universal quiescent states.
Such systems will normally maintain statistics that track the number of times that they pass through their natural quiescent states. For example, most OSs will maintain counts of context switches and most transaction-processing systems maintain counts of the number of transactions complete. These counts, kept for performance-monitoring purposes, can be used to greatly reduce the cost of tracking quiescent periods, as will be shown in later sections.
3.5 SUMMARY OF THREAD ACTIVITY
Tracking quiescent periods is useful only if done very efficiently, otherwise, it is cheaper just to use locks. The mechanism that tracks quiescent periods is called a summary of thread activity. An efficient summary of thread activity is relatively complex, therefore, this section moves from simpler (but slower) implementations to more complex implementations suitable for large-scale shared-memory processing (SMP) and cache-coherent non-uniform memory-access (CC-NUMA) architectures.
For concreteness, we focus on a parallel non-preemptive OS. Therefore, the in-kernel threads map directly to CPUs, and the implementations focus on CPUs rather than threads.
The following sections describe the following implementations: (1) locking-primitive summary, (2) enforced quiescent states, (3) quiescent-state bitmask, and (4) quiescent-state counters.
3.5.1 LOCKING-PRIMITIVE SUMMARY
Perhaps the most straightforward way of identifying quiescent states is to maintain count of the number of locks held by each CPU. When this number drops to zero on a given CPU, that CPU records the fact that it has entered a quiescent state by clearing a its bit in a global bitmask. When the value of the bitmask becomes zero, the end of a quiescent period has been reached. Any subsystem wishing to wait for a quiescent period sets each CPU’s bit in the global bitmask.
Although this approach is simple, it is fatally flawed. First, it is slow, needing to update a global variable each time that a CPU releases its last lock. Second, update disciplines not using locks would have their critical sections violated by this sort of summary of thread activity. Finally, a CPU that ran for an extended period without acquiring any locks (e.g., a CPU in the idle loop) would never clear its bit, despite being in an extended quiescent state.
Therefore, a different approach is required.
3.5.2 ENFORCED QUIESCENT STATES
Another simple approach is to force quiescent states, for example, via a daemon that handles quiescent-period requests. The daemon responds to a request by running on each CPU in turn, then announcing the end of the quiescent period, as shown in Figure 8.
Each CPU that the daemon runs on must do two context switches, one to switch to the daemon, and the other to switch away. A context switch is a quiescent state, so this set of context switches is a quiescent period, as desired. In this case, the summary of thread activity is maintained as part of the local state of the daemon itself.
Figure 8: ENFORCED QUIESCENT STATES
This approach works well, and entered production on Sequent machines in 1993. Context switches are usually from one to three orders of magnitude more expensive than locking primitives, but for read-intensive data structures, the expense is justified. In addition, eliminating locks can greatly simplify deadlock avoidance. Furthermore, batching allows a single quiescent period to satisfy many requests.
Nevertheless, it is possible to do much better.
3.5.3 QUIESCENT-STATE BITMASK
Another approach is to instrument the quiescent states themselves. Each time a given CPU reaches a quiescent state, it clears its bit in a global bitmask. When the bitmask becomes zero, the quiescent state has ended. Any subsystem wishing to wait for a quiescent period sets each CPU’s bit in the global bitmask. A quiescent period measured in this manner is shown in Figure 9.
Figure 9: QUIESCENT-STATE BITMASK
CPU 1 has requested a quiescent period. The bitmask initially resides only in CPU 2's cache, so CPU 1 must first obtain a copy, as shown by the arrow. CPU 1 then writes all one-bits to the bitmask, invalidating the copy in CPU 2's cache, as shown by the line ending in a circle. CPU 2 is the first to pass through a quiescent period (shown by the double vertical line), so it gets a copy from CPU 1 in order to clear its bit, which invalidates the copy in CPU 1's cache. CPU 0 and CPU 3 pass through their quiescent states in a similar manner. Finally, when CPU 1 clears its bit, the bitmask becomes zero, indicating the end of the quiescent period.
To prevent long-running user-level processes and idle CPUs from indefinitely extending a quiescent period, the scheduling-clock interrupt handler records a quiescent state any time that it interrupts either user-mode execution or the idle loop.
This approach can be faster than enforced quiescent states, but the frequent accesses to the shared global bitmask can be quite expensive, as shown in Figure 10.
Figure 10: BITMASK CACHE THRASHING
CPU 2 is frequently forcing the bitmask out of its cache, thereby incurring expensive cache misses each time it passes through a quiescent state.
3.5.4 QUIESCENT-STATE COUNTERS
More-efficient implementations isolate measurement from callback processing. Quiescent states are counted per-CPU and subsystems wait for quiescent periods by registering callbacks on per-CPU callback lists.
An OS kernel's quiescent states either are counted anyway or occur when the CPU is not doing anything useful. Examples of the former include system calls, traps, and context switches. Examples of the latter include the idle loop and removal of CPUs from service. The pre-existing counts of these events are used to implement a quiescent-period-detection algorithm that incurs little added cost.
The basic outline of this algorithm is as follows:
An actual implementation faces these issues:
Our implementation of read-copy update uses quiescent-state counters. An SMP version has been in production in Sequent Dynix/ptx since 1994. The CC-NUMA version went into production in 1996 on a hierarchical-bus architecture with four CPUs per local bus. Each local unit is called a quad.
The four issues listed in the previous section are handled as follows:
4.1 STATE VARIABLES
The state variables for the quad-aware implementation of read-copy update are grouped into generation numbers, bitmasks, statistics, statistics snapshots, and callback lists.
Each quiescent period is identified by a generation number. Since the algorithm maintains loosely coupled state, there are several state variables tracking different generation numbers. The highest generation requested thus far is tracked by rcc_maxgen. The generation currently being serviced is tracked by rcc_curgen, which is replicated per-quad in pq_rcc_curgen. The earliest generation that a particular CPU needs to be completed is tracked by the per-CPU variable rclockgen.
The bitmasks track which CPUs and quads need to pass through a quiescent state in order for the current generation to complete. The set of quads that contain CPUs needing to pass through a quiescent state is tracked by rcc_needctxtmask, and the set of CPUs on a given quad needing to pass through a quiescent state is tracked by the per-quad variable pq_rcc_needctxtmask.
Each CPU tracks the number of context switches in the per-CPU variable cswtchctr. Each CPU tracks the number of system calls and traps from user mode in the per-CPU variables v_syscall and usertrap, respectively. Each CPU tracks the sum of the number of passes through the idle loop and the number of times a process to yielded that CPU in the per-CPU variable syncpoint.
As soon as a given CPU notes the start of a new generation, it snapshots its statistics: cswtchctr into rclockcswtchctr, v_syscall into rclocksyscall, usertrap into rclockusertrap, and syncpoint into rclocksyncpoint.
Read-copy callbacks advance through per-CPU callback lists nxtlist, curlist, and intrlist when quiescent periods are detected, as shown in Figure 11.
4.2 PSEUDO-CODE OVERVIEW
The pseudo-code call tree and function descriptions are as follows:
New callbacks are injected into the system by rc_callback(). While the callbacks are awaiting invocation by rc_intr(), they are kept on per-CPU linked lists, and flow through the system as shown in Figure 11. The rc_onoff() function moves callbacks to the global lists when a CPU is taken out of service. These global lists are processed in the same manner as the per-CPU lists.
Figure 11: FLOW OF CALLBACKS
The actual implementation also includes functions to check for CPUs taking too long to reach a quiescent state. This pinpoints areas that are impacting real-time response.
5 MEASURED PERFORMANCE
Read-copy update performance depends on the fraction f of data-structure accesses that modify that data structure, and on the degree to which read-copy callbacks may be batched. Note that batching occurs naturally if several callbacks are registered during a single quiescent period. The ratio of read-copy update overhead to that of an uncontended simple spinlock is shown in Figure 12 for various batch sizes and for several relatively large values of f. These measurements were made on a Sequent NUMA-Q system with 32 Intel Pentium Pro processors.
Note that all measurements taken with f=0.01 or less show that use of read-copy update results in large speedups compared to an uncontended simple spinlock. This low-contention case is the worst case for read-copy update. Under heavy contention, the overhead of simple spinlock rises dramatically, whereas heavy contention actually reduces the overhead of read-copy update due to batching. Further, as noted below, smaller values of f improve read-copy update performance. Finally, this data assumes multiple updating threads. A single updating thread would not need an update-side spinlock.
Figure 12: OVERHEAD OF READ-COPY UPDATE
Two examples will help to put the value of f in better perspective. The first example is a routing table for a system connected to the Internet. Many Internet routing protocols process routing changes at most every minute or so. Therefore, a system transmitting at the low rate of 100 packets per second would need to perform a routing-table update at most once per 6,000 packets, for f<10-3. The second example is a system with 100 mirrored disks, each of which has an MTBF of 100,000 hours. A transaction-processing system performing 10,000 disk I/Os per second would perform in excess of 1010 I/Os on the average before having to update the internal tables tracking which disk contains which data. This yields a value below 10-10 for f. In these cases, read-copy update vastly outperforms simpler locking schemes, since read-copy update overhead goes to zero as f approaches zero.
6 COMPARISON TO OTHER LOCKS
There are four components to read-copy-update overhead:
Equation 1, Equation 2, Equation 3, and Equation 4 give the read-copy
overhead incurred for each of these four components: per hardclock(), per
generation, per batch, and per callback, respectively:
The worst-case cost of an isolated callback is m times the per-hardclock()
cost plus the sum of the rest of the costs, as shown in Equation 5:
Typical costs may be computed assuming a system-wide Poisson-distributed
inter-arrival rate of l per generation,
as shown in Equation 6.
The expected number of batches Nb(k) is given by the
well-known solution to the occupancy problem:
Substituting Equation 7 and Equation 8 into Equation 6 and substituting
Equation 1, Equation 2, Equation 3, and Equation 4 into the result yields
the desired expression for the typical cost:
Figure 13 displays read-copy update overhead as a function of the number of CPUs. At these typical latency ratios and moderate-to-high update fractions, read-copy update outperforms the other locking primitives. Note particularly that the overhead of the non-worst-case read-copy overheads do not increase with increasing numbers of CPUs, due to the batching capability of read-copy update. Although simple spinlock also shows good scaling, this good behavior is restricted to low contention.
Figure 13: OVERHEAD VS. NUMBER OF CPUs
Figure 14 shows read-copy overhead as a function of the update fraction f. As expected, read-copy update performs best when the update fraction is low. Update fractions as low as 10-10 are not uncommon .
Figure 14: OVERHEAD VS. UPDATE FRACTION
Figure 15 shows read-copy overhead as a function of the memory-latency ratio r. The distributed reader-writer primitives have some performance benefit at high latency ratios, but this performance benefit is offset in many cases by high contention, by larger numbers of CPUs, or by lower update fractions, as shown in Figure 15
Figure 15: OVERHEAD VS. LATENCY RATIO
The situation shown in Figure 15 is far from extreme. As noted earlier, common situations can result in update fractions below 10-10.
Figure 16: OVERHEAD VS. LATENCY RATIO FOR LOW f
Note finally that all of these costs assume that the update-side processing for read-copy update is guarded by a simple spinlock. In cases where the update-side processing may use a more aggressive locking design (for example, if only one thread does updates), read-copy update will have an even greater performance advantage.
7 RELATED WORK
Reader-writer spinlocks allow reading processes to proceed concurrently. However, updating processes may not run concurrently with each other or with reading processes. In addition, reader-writer spinlocks exact significant synchronization overhead from reading processes. On the other hand, reader-writer spinlocks allow writers to block readers and vice versa, thereby avoiding stale data. This tradeoff is shown in Figure 17—exclusion between readers and writers imposes lock-contention costs and increases the time required to become aware of an external event.
Figure 17: LATENCY OF READ-COPY UPDATE COMPARED TO READER-WRITER SPINLOCK
Wait-free synchronization allows reading and updating processes to run concurrently, but again exacts significant synchronization overhead. It also requires that memory used for a given type of data structure never be subsequently used for any other type of data structure, and that reading threads write to shared storage. On parallel computers, these writes will result in high-latency cache misses. On the other hand, wait-free synchronization provides wait-free processing to updates as well as to reads, and also avoids stale data.
Timestamping and versioning concurrency-control is in some ways similar to read-copy update, but imposes synchronization overhead on reading processes . Chaotic relaxation accepts stale data to reduce locking overhead, but requires highly structured data.
Manber and Ladner describe an algorithm that defers freeing a given node until all processes running at the time the node was removed have terminated. This allows reading processes to run concurrently with updating processes, but does not handle non-terminating processes such as those found in OSs and server applications. In addition, they do not describe an efficient mechanism for tracking blocks awaiting deferred free.
Pugh uses a technique similar to that of Manber and Ladner, but notes that (expensive) read-side state update can handle non-terminating processes. However, Pugh leaves to the reader the mechanism for efficiently tracking blocks awaiting deferred free.
Kung and Lea [7, 8] describe use of a garbage collector to manage the list of blocks awaiting deferred free. However, garbage collectors are often not available, and their overhead renders them infeasible in many situations. In particular, the traditional reference-counting approach incurs expensive memory writes for reading threads. Even when garbage collectors are available and when their overhead is acceptable, they do not address situations where some operation other than freeing memory is to be performed in a timely manner at the end of the quiescent period.
Jacobson describes perhaps the simplest possible deferred-free technique: simply waiting a fixed amount of time before freeing blocks awaiting deferred free. This works if there is a well-defined upper bound on the length of quiescent periods. However, longer-than-expected quiescent periods (perhaps due to greater-than-expected load or data-structure size) can result in memory-corruption failures, with no feasible means of diagnosis.
8 SUMMARY AND CONCLUSIONS
We have presented a novel update discipline, named read-copy update, that provides great reductions in synchronization overhead, tolerates non-terminating threads and reduces deadlock-avoidance complexity. Read-copy update generally gives the best performance improvement for read-mostly algorithms or under high contention. In some cases, the need for synchronization operations is completely eliminated.
We have delineated read-copy update’s area of applicability: Data structures that are often accessed and seldom updated, where a modest amount of memory may be spared for structures waiting on a quiescent period, and where stale data may be tolerated or can be suppressed.
We have provided a firm theoretical basis for read-copy update, along with a very efficient implementation. This implementation, which uses a summary of thread activity, fills an important gap in earlier work with concurrent update algorithms. The implementation has run in production on Sequent machines since 1994.
We have presented measurements that demonstrate order-of-magnitude reductions in overhead compared to simple spinlock. These comparisons are quite conservative: even greater savings would be realized if the simple spinlock were heavily contended.
We owe thanks to Stuart Friedberg, Doug Miller, Jan-Simon Pendry, Chandrasekhar Pulamarasetti, Jay Vosburgh and Dave Wolfe for their willingness to try out read-copy update, and to Ken Dove, Brent Kingsbury, and to Phil Krueger and his Base-OS Reading Group for many helpful discussions. We are greatful to Dale Goebel, Dave Stewart, John Cherry, and Hans Tannenberger for their support of this work.
This work was done with the aid of Macsyma, a large symbolic manipulation program developed at the MIT Laboratory for Computer Science and supported from 1975 to 1983 by the National Aeronautics and Space Administration under grant NSG 1323, by the Office of Naval Research under grant N00014-77-C-0641, by the U. S. Department of Energy under grant ET-78-C-02-4687, and by the U. S. Air Force under grant F49620-79-C-020, between 1982 and 1992 by Symbolics, Inc. of Burlington Mass., and since 1992 by Macsyma, Inc. of Arlington, Mass. Macsyma is a registered trademark of Macsyma, Inc.
Gregory R. Adams. Concurrent Programming, Principles, and Practices, Benjamin Cummins, 1991.
N. S. Barghouti and G. E. Kaiser. Concurrency control in advanced database applications, ACM Computing Surveys, September 1991.
Doug Burger, James R. Goodman, and Alain Kägi. Memory bandwidth limitations of future microprocessors, ISCA’96, (May 1996), pages 78-89.
John L. Hennessy and Norman P. Jouppi. Computer technology and architecture: An evolving interaction. IEEE Computer, page 18-28, Sept. 1991.
Maurice Herlihy. Implementing highly concurrent data objects, ACM Transactions on Programming Languages and Systems, vol. 15 #5, November, 1993, pages 745-770.
Van Jacobson. Avoid read-side locking via delayed free, private communication, September, 1993.
H. T. Kung and Q. Lehman. Concurrent manipulation of binary search trees, ACM Trans. on Database Systems, Vol. 5, No. 3 (Sept. 1980), 354-382.
Doug Lea. Concurrent Programming in Java, Addison-Wesley, 1997.
T. Lovett and R. Clapp. STiNG: A CC-NUMA computer system for the commercial marketplace. In Proceedings of the 23rd International Symposium on Computer Architecture, pages 308-317, May 1996.
Udi Manber and Richard E. Ladner. Concurrency control in a dynamic search structure, ACM Trans. on Database Systems, Vol. 9, No. 3 (Sept 1984), 439-455.
Paul E. McKenney. Selecting locking primitives for parallel programs, Communications of the ACM, Vol. 39, No. 10 (1996).
Paul E. McKenney. Comparing performance of read-copy update and other locking primitives, Sequent TR-SQNT-98-PEM-1, January 1998.
Paul E. McKenney. Implementation and performance of read-copy update, Sequent TR-SQNT-98-PEM-4.0, March 1998.
John M. Mellor-Crummey and Michael L. Scott. Scalable reader-writer synchronization for shared-memory multiprocessors, Proceedings of the Third PPOPP, Williamsburg, VA, April, 1991, pages 106-113.
William Pugh. Concurrent Maintenance of Skip Lists, Department of Computer Science, University of Maryland, CS-TR-2222.1, June 1990.
Michael L. Scott and John M. Mellor-Crummey, Fast, contention-free combining tree barriers, University of Rochester Computer Science Department TR#CS.92.TR429, June 1992.
John D. Slingwine and Paul E. McKenney. System and Method for Achieving Reduced Overhead Mutual-Exclusion in a Computer System. US Patent # 5,442,758, August 1995.
Harold S. Stone and John Cocke. Computer architecture in the 1990s. IEEE Computer, pages 30-38, Sept. 1991. | <urn:uuid:fa489f63-b57c-42ed-b721-e835dfc15144> | CC-MAIN-2016-26 | http://www.rdrop.com/users/paulmck/rclock/intro/rclock_intro.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783396459.32/warc/CC-MAIN-20160624154956-00050-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.894816 | 6,995 | 2.578125 | 3 |
Keogh, including Kehoe and Mac
Keogh, almost equally common forms of the same Irish surname -
Mac Eochaidh - just misses a place in the hundred most numerous
names in Ireland. It is chiefly found in the province of
Leinster, the spelling Kehoe being usual in Co. Wexford.
The present Irish spelling of this name is MacEochaibh.
Formerly in Munster it was MacCeoch or Mac Ceoch which was
retained while Gaelic survived there as the vernacular.
Outside Leinster Mac Keoghs are mainly located in the
neighborhood of Limerick; the place name Ballmackeogh is in Co.
Tipperary a few miles from that city. This was the
homeland of one of the three distinct septs of Mac Keoghs.
The second was in the Ui Maine group. Their eponymous
ancestor was Eochaidh O'Kelly; they were lords of Magh Finn and
their territory of Moyfinn in the barony of Athlone, Co.
Roscommon, long known as Keogh's Country, was popularly
so-called even in quite recent times. The place Keoghville
in the parish of Taghmaconnell took its name from them.
The third and historically the most important sept were the Mac
Keoghs of Leinster. These are of the same stock as the
O'Byrnes and were hereditary bards to that great family. With
them they migrated in early mediaeval times from north Kildare
to Co. Wicklow, whence they spread later to Co. Wexford.
The Four Masters describe Maolmuire Mac Keogh as chief professor
of poetry in Leinster in 1534, and several fine poets of the
name are cited by Douglas Hyde in his Literary History of | <urn:uuid:c9bd88a0-eb31-4849-910c-e7a38b60ad00> | CC-MAIN-2016-26 | http://www.electricscotland.com/webclans/scotsirish/keogh.htm | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783398216.41/warc/CC-MAIN-20160624154958-00070-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.981914 | 405 | 2.8125 | 3 |
The southern California coast has been a favored place to live for nearly 12,000 years. Dotted with marshes, estuaries, cliffs, and open beaches, with islands and mountains lying nearby, the area is rich in resources. How humans have fit into this ecological diverse and ever-changing landscape is a constant theme in the prehistory of the region. Using comparative studies of island and coastal cultures from the Pacific, the authors show how the study of southern California's past can enlighten us about coastal adaptations worldwide. Drawing on sources from anthropology, ethnohistory, geoscience, and archaeology, their findings are presented in a readable fashion that will make Islanders and Mainlanders of interest not only to a wide range of scholars but to the general public as well. Jeffrey H. Altschul is President and Donn R. Grenda is Director of the California Office of Statistical Research, Inc., a cultural resource management consulting firm. Both have been extremely active in southern California archaeology, working on sites on the mainland and the Channel Islands. | <urn:uuid:a3608aba-fa54-44cf-92f3-31f2841c202f> | CC-MAIN-2016-26 | http://www.uapress.arizona.edu/Books/bid1314.htm | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783400031.51/warc/CC-MAIN-20160624155000-00088-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.941095 | 214 | 3.078125 | 3 |
Sand Tiger Shark Range
- Average life span in the wild:
- 15 years or more
- 6.5 to 10.5 ft (2 to 3.2 m)
- 200 to 350 lbs (91 to 159 kg)
- Group name:
- School or shoal
- Did you know?
- Sand sharks survive well in captivity, and their large size and menacing appearance makes them an extremely popular addition to public aquariums.
- Size relative to a 6-ft (2-m) man
Please add a "relative" entry to your dictionary.
Sand sharks, also known as sand tigers and gray nurse sharks, have a deceivingly ferocious look. They are large-bodied and display a mouthful of sharp teeth that protrude in all directions, even when the mouth is shut. Despite this, they are a docile, non-aggressive species, known to attack humans only when bothered first.
Sand sharks are brownish-gray with rust-colored spots on top and white underneath. They have a flattened, cone-shaped snout and a distinctive, oblong tail with a notched, upper lobe that is significantly longer than the lobe below. Individuals range in size from 6.5 to 10.5 feet (2 to 3.2 meters) in length.
Their name comes from their tendency toward shoreline habitats, and they are often seen trolling the ocean floor in the surf zone, very close to shore. They are found in warm or temperate waters throughout the world's oceans, except the eastern Pacific.
Sand tigers are the only shark known to come to the surface and gulp air. They store the air in their stomachs, which allows them to float motionless in the water, seeking prey. They are voracious predators, feeding at night and generally staying close to the bottom. Their staple is small fish, but they will eat crustaceans and squid as well. They occasionally hunt in groups, and have even been known to attack full fishing nets.
Although this species is widespread and is not widely fished for food, it has one of the lowest reproduction rates of all sharks and is susceptible to even minimal population pressure. For this reason, it is listed as vulnerable and is protected in much of its range.
Learn all you wanted to know about sharks with videos, quizzes, puzzles, and more.
Now under threat in the increasingly humanized seas, sharks still find refuge and freedom in the Bahamas. Join photographer Brian Skerry in what he describes as "a Garden of Eden for sharks."
Learn more about what National Geographic/Waitt grantee Nick Whitney is doing to identify mating behavior in adult nurse sharks during their mating season in the Florida Keys.
Discover a pristine reef where sharks reign supreme in this National Geographic magazine feature.
Find out what makes the great white shark the largest predatory fish on Earth with this interactive feature from NGC's Great White Odyssey. | <urn:uuid:beb5aa0a-1596-4308-8864-453dcd8cadae> | CC-MAIN-2016-26 | http://animals.nationalgeographic.com/animals/fish/sand-tiger-shark/ | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783398075.47/warc/CC-MAIN-20160624154958-00079-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.95458 | 601 | 3.1875 | 3 |
In a study published in the Oct. 9 issue of the New England Journal of Medicine, Drs. Tim Hughes at the Institute of Medical and Veterinary Science in Adelaide, Australia, Jerry Radich at Fred Hutchinson and Jaspal Kaeda at Hammersmith in London used molecular analysis to detect residual cancer cells in leukemia patients enrolled in a clinical trial to compare two drug regimens. The researchers found their method which is based on a technique called polymerase chain reaction, or PCR, to be far more stringent at picking up traces of cancer that could lead to relapse than the standard test known as cytogenetic analysis, in which chromosomes are examined under a microscope.
The study was part of a large international clinical trial to compare the response of patients with chronic myeloid leukemia to Gleevec, a recently approved drug manufactured by Novartis, with a combination therapy consisting of interferon and cytarabine.
According to Radich, the study, which is the first to use the technique to assess the extent of response to drug therapy, opens the door to a new conceptual approach for the design of future clinical trials.
"Our results tell us that PCR can be used to stratify patients according to their level of remission by measuring the number of cancer cells that remain after patients are in cytogenetic remission, and those numbers correlate with how likely it is that a patient's disease will progress," Radich said. "We found that patients treated with Gleevec experienced a deeper remission that was associated with a better prognosis than patients treated with interferon plus cyarabine."
In addition, he said, the use of molecular diagnosis of remission as a surrogate endpoint could drastically reduce the duration of conducting large-scale clinical trials.
"Rather than waiting five years to know how well a new therapy works, we can have answers in a year, which will make the best new therapies available faster."
Consistent with previously published results, the new study found that significantly more patients entered remission as judged by cytogenetic analysis when treated with Gleevec than with a combination of interferon and cytarabine. But using PCR analysis, researchers could for the first time detect differences in what Radich described as the "depth of remission" depending on which drug therapy patients received. Those differences foretold the likelihood that a patient's disease would worsen within two years of achieving remission.
Chronic myeloid leukemia, or CML, is a rare cancer of the blood that affects about 4,300 people, primarily adults, each year. CML initially presents as a relatively indolent condition, called the "chronic phase," during which there is uncontrolled expansion of myeloid cells (white blood cell precursors). Over time, the chronic phase can develop into a "blast crisis," an aggressive phase that is characterized by excessive production of blasts, which are abnormal immature blood cells. Blast crisis is commonly fatal, as patients suffer from bleeding and infections. Currently, bone-marrow or stem-cell transplantation is the only known cure for the disease. Patients who elect not to pursue transplantation, have risk factors that make them ineligible or who do not have tissue-compatible donors are treated with drug therapy.
Unlike all other cancers, CML owes its origin to a single genetic defect: the breakage and swapping of portions of chromosomes 9 and 22, a rearrangement that produces a truncated chromosome 22 known as the Philadelphia chromosome. A single cell with this cancer-causing defect can divide to form millions of copies, or clones.
The rearrangement results in the formation of a new gene, bcr-abl, that consists of DNA from each intact chromosome - bcr on chromosome 22 and abl on chromosome 9 - juxtaposed at the breakpoint fusion on the Philadelphia chromosome. The rearrangement can be detected by microscopic examination of blood cells in a procedure known as cytogenetic analysis, which is used to evaluate the extent of the disease and response to treatment. The PCR test, which Radich pioneered in earlier studies to evaluate relapse in stem-cell transplant recipients, essentially counts the number of copies of the bcr-abl gene and can pick up very small numbers of cancer cells that would not be seen by cytogenetic analysis.
The new study involved 1,106 patients between the ages of 18 and 70 with chronic-phase CML who were randomly assigned to a group that received Gleevec or interferon plus cytababine. After a median 19 months of follow-up, 408 patients in the Gleevec group and 47 in the interferon/cytarabine group had a complete remission as judged by cytogenetic analysis (no detectable Philadelphia chromosome by microscopic analysis). Of these patients, 333 patients in the Gleevec group and 37 in the interferon/cytarabine group had samples available for PCR testing.
The researchers measured the reduction in the number of bcr-abl gene copies, as determined by PCR analysis of the amount of RNA produced by the gene, at the time of complete cytogenetic remission as well as at time points up to 18 months later.
At the time of cytogenetic remission, the median reduction in the levels of bcr-abl was 250-fold in the Gleevec group compared to 220-fold in the interferon/cytarabine group. Thirty-two percent of the Gleevec-group patients in cytogenetic remission had a reduction of at least 300-fold, compared to none of the interferon/cytarabine patients in cytogenetic remission. Bcr-abl levels continued to drop during follow-up, with a median reduction of 370-fold in the Gleevec group and 250-fold in the interferon/cytarabine group 15 months after achievement of a complete cytogenetic remission.
For patients with a reduction in bcr-abl levels of at least 300-fold, the probability of remaining in remission was 100 percent at 24 months, as compared with 95 percent for patients who had less than a 300-fold reduction and 85 percent for patients who did not have a complete cytogenetic remission. Patients will continue to be monitored to determine whether their molecular response to treatment as judged by the PCR test continues to correlate with remission and survival. Despite the strong response to Gleevec seen in a significant fraction of patients, only 3 percent of those who had achieved complete cytogenetic remission had levels of bcr-abl that dropped below detectable levels, which is equivalent to about a 450-fold reduction.
"The fact that bcr-abl levels rarely drop to undetectable levels with Gleevec is perhaps worrisome," Radich said. "This means that that the cancer is not completely going away, and there may be potential for the disease to recur." Relapses after long-term therapy with Gleevec have been increasingly described.
Radich and colleagues are now initiating clinical trials to further optimize drug therapy for CML using bcr-abl levels as the primary measure of drug effectiveness. The trials will be administered through the Southwest Oncology Group, a national clinical trials cooperative group whose statistical center is housed partly within Fred Hutchinson.
Collaborators on the study included lead author Dr. Tim Hughes at the Institute of Medical and Veterinary Science in Adelaide, Australia, and colleagues at Hammersmith Hospital in London; the University of Heidelberg; and Novartis Pharma of Basel, which funded the study. | <urn:uuid:7c6e0b31-c5d0-4442-a6b3-d14fcf98659c> | CC-MAIN-2016-26 | http://www.eurekalert.org/pub_releases/2003-10/fhcr-mtp100803.php | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783391766.5/warc/CC-MAIN-20160624154951-00097-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.952685 | 1,532 | 2.65625 | 3 |
State reports first flu deaths of season
Posted December 3, 2013
Raleigh, N.C. — The state Department of Health and Human Services said Tuesday that three people have died from the flu, marking the first deaths of the annual flu season.
The patients, all middle-age adults with underlying medical conditions, were from eastern North Carolina, the Triad region and the Charlotte area. All three died during the past two weeks after testing positive for Influenza A, one of the main types of flu responsible for seasonal flu epidemics each year.
"We hope that these tragic cases will help alert other people to the risks associated with contracting flu," Dr. Robin Gary Cummings, acting state health director, said in a statement.
Cases of flu have been relatively low in North Carolina so far this season but are beginning to trend upward, public health officials said. Flu season typically peaks during January and February.
Complications from flu can be particularly dangerous for high-risk groups, including infants and toddlers under age 2, pregnant women and people with chronic medical conditions, such as asthma, diabetes, heart disease or immune system problems.
"Anyone in a high-risk group who gets the flu should see a doctor right away so they can receive treatment with an antiviral drug," Cummings said. "Early treatment with an antiviral drug can mean the difference between a mild illness and a very serious illness."
Flu vaccination is the most effective treatment against the flu. The immunization takes about two weeks to become effective, and the vaccine is widely available and protects against various strains of flu circulating this year, including H1N1.
Public health officials also encourage people to use the following precautions to protect against the spread of flu and other viruses:
- Cover coughs and sneezes with a tissue and then discard the tissue promptly.
- Wash hands frequently, preferably with soap and water or an approved hand sanitizer.
- Stay home when you are sick until you are fever free for at least 24 hours. | <urn:uuid:70c704b4-ca1f-424e-8333-833e7b4308bb> | CC-MAIN-2016-26 | http://www.wral.com/state-reports-first-flu-deaths-of-season/13176623/ | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783403825.35/warc/CC-MAIN-20160624155003-00097-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.969389 | 413 | 2.78125 | 3 |
Jeff Schmaltz, MODIS Rapid Response Team, NASA/GSFC
Centered farther west than previous day’s images in this series, this true-color image from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite shows the widespread nature of the fires in central Africa. This image shows fires burning in southwestern Sudan (right) and its western neighbor, Chad. Below is the Central African Republic. The fires in Chad are burning in an area that encompasses a broad expanse of wetlands in a region called Salamat.
This image highlights the transition from the Sahara Desert (top), to the Sahel (lighter green) to tropical savannas (darker green). The Sahel is a loosely defined strip of transitional vegetation that separates the desert from the tropical savannas to the south. The region is used for farming and grazing, and because of the difficult environmental conditions that exist at the border of the desert, the region is very sensitive to human-induced land cover change. There is increasing concern that clearing natural vegetation for farming exposes the fragile topsoil to the brunt of desert winds, and that these changes may be permitting the expansion of the region’s deserts.
Note: Often times, due to the size, browsers have a difficult time opening and displaying images. If you experiece an error when clicking on an image link, please try directly downloading the image (using a right click, save as method) to view it locally. | <urn:uuid:06d8e177-afcc-445b-847d-cea3f6013fdf> | CC-MAIN-2016-26 | http://visibleearth.nasa.gov/view.php?id=62757 | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783397111.67/warc/CC-MAIN-20160624154957-00130-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.897209 | 304 | 3.578125 | 4 |
The topic of my masters thesis project at George Mason University
is the study of a genetic algorithm approach to predicting protein
structure in abstract proteins folded in 3-dimensional lattices.
This is an important topic in the field of proteomics and one of
the "grand challenges" of molecular biology. If you are
unfamiliar with the protein folding problem, check out my introduction
to protein folding.
Hydrophobic Packing Problems
Because hydrophobicity is thought to influence something like 70%
of a protein's folding behavior, I am discarding the electrodynamics
and mechanical constraints in real world proteins, and abstracting
the proteins as simple chains of hydrophobic or polar amino acids.
Instead of folding these proteins in normal three-space, we will
fold our abstract proteins onto an artificial three dimensional
These are the essentials of the "hydrophobic
packing model" pioneered by K.A. Dill. Hydrophobic packing
models discard the ancillary details of protein folding without
reducing the computational complexity of the problem. Thus, we can
devise problem solving systems which can scale-up
to solving real-world protein folding problems.
Evolutionary Computation Approach
Because the protein folding problem is considered to be an NP-complete
problem, most investigators have given up on trying to find polynomial
time solutions, and turned to massively parallel computers to derive
solutions by brute force. These approaches are unacceptable for
- Interesting proteins are typically large: several thousand amino
acids in length. An exhaustive computer search for the optimal
solution would require billions of years even harnessing all the
computer power on the planet.
- Such approaches contribute nothing to the understanding of
the pathways by which proteins fold. Big powerful computers are
impressive engineering feats, but not scientifically useful because
they can't tell you "why" proteins fold the way they
Other research has turned to non-admissible methods which use clever
heuristics for deriving the structures of proteins. Genetic algorithms,
because they have been used to successfully solve other problems
with NP-complete characteristics, are also a popular approach and
can be further enhanced using heuristics. My research utilizes a
novel genetic algorithm to folding proteins.
No Free Lunch
Unlike exhaustive search techniques, genetic algorithms utilize
non-admissible heuristics and thus cannot gaurentee polynomial
time solutions... and even if a GA arrived at the optimal solution,
it wouldn't know that the solution is optimal because it hasn't
examined all of the conformations possible. Gaurenteeing a solution
is tantemount to saying that you know the optimal solution's fitness
value ahead of time. But since fitness relies on structure, you
would have to know the structure ahead of time as well. This is
the so-called "termination problem" in GAs, and is also
an unsolved problem. | <urn:uuid:b0055411-dc9b-4c05-9206-65df28163ac3> | CC-MAIN-2016-26 | http://protein-folding.org/index.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783400572.45/warc/CC-MAIN-20160624155000-00162-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.90829 | 617 | 2.546875 | 3 |
Most of us don’t recognize the importance of exercises, games and walk for fitness and weight loss. Many people use artificial ways for dissolving extra fats from their body but don’t spend a few minutes on exercise. While watching TV and working on Computer we spend three hour, most of us working in offices spend 8 hours a day. The common problem among for these workers is obesity which shows lack of interest in physical activity like sports and walk for fitness. Many communities and health centers make programs for awareness and they also used to declare a day for walk. These activities not only control weight but give energy and prevent many diseases.
Aerobics and jogging will help against heart disease and strengthens bones. It is not only exercise which burns calories, mowing a lawn, cleaning house and playing tennis or badminton, weekly will also give good results for physical fitness. | <urn:uuid:fac00f54-da7a-47ca-84b5-d48569c0503a> | CC-MAIN-2016-26 | http://www.funnp.com/misc/funny_workout_exercise_fitness_weight_names.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783395620.9/warc/CC-MAIN-20160624154955-00039-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.962989 | 180 | 2.78125 | 3 |
|WORLD METEOROLOGICAL ORGANIZATION||
|Explanation of the criteria for classification and numbering of components|| L20.3.10
|Explanation of the dates on the component's description|
GROUNDWATER HEAD DRAWDOWNS BASED ON ANALYTICAL SOLUTIONS (AQ-AP)
1. Purpose and objectives
Calculation of head drawdowns in aquifers and fluxes across aquitards, based on analytical solutions.
The relevant physical processes are described by Darcy's law for groundwater flow and the mass continuity equation. Existing analytical solutions are implemented to calculate the head drawdown in aquifers and, as a derived variable, changes in the vertical flux across the aquitards. Both steady-state and transient systems can be modelled. The well rates can vary either step-wise or piece-wise linear in time.
The following two principal systems are available:
- Multi-layered aquifer-aquitard system, assuming horizontal flow in
- Fully three-dimensional flow in a single aquifer overlain by an
In both cases, a laterally infinite system is assumed and storage in
the aquitards is neglected. The latter implies that the vertical velocity is constant over the whole aquitard thickness.
Well data (location and abstraction rate), hydrogeologic parameters pertaining to aquifers (transmissivity, hydraulic conductivity, storage coefficient) and aquitards (hydraulic resistance).
- Graphs: variation in time in selected points, linear and logarithmic time axis;
- Maps: contours over an area;
- Profiles: variation over a line section across a model area;
- Selected points: values at discrete points, and at specific time instants.
5. Operational requirements and restrictions
The AQ-software packages run on Personal Computers under DOS, OS2 and WINDOWS95 operating systems. A pen plotter is required, unless other plot viewing systems are used. Two types of plotters are supported: HP7475A (or HP-compatible) and Calcomp MODEL84/81.
AQ-AP consists of a number of computer programs communicating through data files. The programs are controlled interactively through screen menus in English, and feature a unit versatility and full error checking procedures.
The model can be handled by persons familiar with general hydrogeological principles and groundwater modelling concepts. A basic knowledge of statistics is required.
Easy installation following the manual. The model package takes a short time to acquire proficiency in handling. As the source code is not supplied, no FORTRAN compiler is needed.
6. Form of presentation
Run version of the computer program package on a number of diskettes.
A comprehensive users' manual in English.
7. Operational experience
The model has been widely used primarily The Netherlands since 1988, especially in the operationally orientated areas of groundwater investigations, e.g. by water supply companies and consulting engineers.
8. Originator and technical support
The program is developed at IWACO B.V., Consultants for Water and Environment, Rotterdam, The Netherlands. Technical support will be provided by IWACO B.V.
10. Conditions on use
A charge will be made for supplying the model. Updates of the new run versions will be forwarded to users automatically during a certain period of time.
|(First entered: 8 NOV 89||
Last updated: 19 JAN 98) | <urn:uuid:9b217a86-5461-49c3-8974-d02407a88968> | CC-MAIN-2016-26 | http://www.wmo.int/pages/prog/hwrp/homs/Components/English/l20310.htm | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783400031.51/warc/CC-MAIN-20160624155000-00126-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.866817 | 732 | 2.671875 | 3 |
1. A contest between nations or states, carried on by force, whether for defence, for revenging insults and redressing wrongs, for the extension of commerce, for the acquisition of territory, for obtaining and establishing the superiority and dominion of one over the other, or for any other purpose; armed conflict of sovereign powers; declared and open hostilities. Men will ever distinguish war from mere bloodshed. (F. W. Robertson)
As war is the contest of nations or states, it always implies that such contest is authorised by the monarch or the sovereign power of the nation. A war begun by attacking another nation, is called an offensive war, and such attack is aggressive. War undertaken to repel invasion, or the attacks of an enemy, is called defensive.
6. A state of opposition or contest; an act of opposition; an inimical contest, act, or action; enmity; hostility. Raised impious war in heaven. The words of his mouth were smoother than butter, but war was in his heart. (Ps. Lv. 21) d00
Civil war, a war between different sections or parties of the same country or nation. Holy war. See Holy. Man of war.
Public war, a war between independent sovereign states. War cry, a cry or signal used in war; as, the indian war cry. War dance, a dance among savages preliminary to going to war. Among the North American Indians, it is begun by some distinguished chief, and whoever joins in it thereby enlists as one of the party engaged in a warlike excursion. War field, a field of war or battle. War horse, a horse used in war; the horse of a cavalry soldier; especially, a strong, powerful, spirited horse for military service; a charger. War paint, paint put on the face and other parts of the body by savages, as a token of going to war. Wash the war paint from your faces. . War song, a song of or pertaining to war; especially, among the American Indians, a song at the war dance, full of incitements to military ardor. War whoop, a war cry, especially that uttered by the American Indians.
Origin: OE. & AS. Werre; akin to OHG. Werra scandal, quarrel, sedition, werran to confound, mix, D. Warren, G. Wirren, verwirren, to embroil, confound, disturb, and perhaps to E. Worse; cf. OF. Werre war, F. Querre, of Teutonic origin. Cf. Guerrilla, Warrior. | <urn:uuid:c96aca68-d6a0-4007-91a3-813b7354c50d> | CC-MAIN-2016-26 | http://www.biology-online.org/bodict/index.php?title=War&redirect=no | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783408840.13/warc/CC-MAIN-20160624155008-00062-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.940214 | 549 | 3.1875 | 3 |
In this section
Head injuries are common in children of all ages. Causes include falls, sporting accidents, road traffic accidents and non-accidental injuries.
A key aim of head injury management is to prevent or minimise secondary brain injury which occurs as a result of hypoxia, poor cerebral perfusion, cerebral bleeding, hypoglycaemia, seizures and fever
· ABC: ensure that the child's airway,
cervical spine, breathing and circulation are secure.
· Rapidly assess the child's mental state using the AVPU scale. Use firm supraorbital pressure or jaw thrust as the painful stimulus.
* suspect basal skull fracture if these signs present
Multiple trauma present, see
Major trauma guideline
Cervical spine imaging
Venous blood gas and blood sugar level (especially in small children and in adolescents who have been drinking alcohol)
ECG (query arrhythmia as cause of fall)
≥ 4 years
< 4 years
To verbal stimuli
To painful stimuli
No response to pain
Best verbal response
Orientated and converses
Appropriate words or social smile, fixes, follows
Confused and converses
Cries but consolable; less than usual words
Moans to pain
No response to pain
Best motor response
Obeys verbal commands
Spontaneous or obeys verbal commands
Localises to stimuli
Withdraws to stimuli
Abnormal flexion to pain (decorticate)
Abnormal extension to pain (decerebrate)
Minor – jump to Management
Minor head injury:
Moderate Head Injury:
Severe Head Injury:
The initial aim of management of a child with a serious head injury is prevention of secondary brain damage. The key aims are to maintain oxygenation, ventilation and circulation, and to avoid rises in intracranial pressure (ICP).
Urgent CT of head and c-spine. Ensure early neurosurgical and ICU intervention.
Cervical spine immobilisation should be maintained even if cervical spine imaging is normal.
Intubation and ventilation:
In consultation with the neurosurgeon consider measures to decrease intracranial pressure:
Control seizures: see
Analgesia: sufficient analgesia should be administered by careful titration. Head injured children are often more sensitive to opioids.
Head injury - general advice information sheet - should be given to all parents.
Ensure the parents have clear instructions regarding the management of their child at home especially to return to hospital immediately if their child:
Head Injury handout - Return to sport
For advice and inter-hospital (including ICU level) transfers ring the Sick Child Hotline: (03) 9345 7007 | <urn:uuid:a402033e-635d-4d3e-ab88-e32959d39853> | CC-MAIN-2016-26 | http://www.rch.org.au/clinicalguide/guideline_index/Head_Injury_Guideline/ | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783393533.44/warc/CC-MAIN-20160624154953-00050-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.845358 | 565 | 3.546875 | 4 |
Until now, researchers were skeptical that such molecular devices could survive the rigors of real-world manufacturing and use, which involve high temperatures and up to one trillion operational cycles. But scientists at the University of California, Riverside and North Carolina State University have demonstrated that molecular memories are indeed both durable and practical - a finding that could spur development of the technology.
The scientists' results, in a paper titled "Molecular Memories that Survive Silicon Device Processing and Real-World Operation," are described in the Nov. 28 issue of the journal Science.
Dr. Jonathan S. Lindsey, Glaxo Distinguished University Professor of Chemistry at NC State and one of the paper's authors, said the team was faced with a very basic problem. "If molecular materials can't compete against semiconductor materials under the rigorous conditions of the real world," he said, "then trying to implement them in electronic devices would be pointless. Because our goal is to develop molecule-based memory devices, we first had to test their durability and stability."
Led by Dr. David F. Bocian, professor of chemistry at the University of California, Riverside, the team attached porphyrins - disk-shaped organic molecules similar to chlorophyll - with specific electronic properties to an electroactive surface, storing information in the form of the molecules' positive charges.
After a series of tests, the scientists found that the resulting molecular memories were "extremely robust" and offered clear advantages over traditional semiconductor-based technology.
"The porphyrin-based information-storage elements exhibit charge-retention times that are long (minutes) compared with those of the semiconductor elements in dynamic random access devices (tens of milliseconds)," the university chemists report in their paper.
In addition, their testing showed that such molecule-based information-storage devices "meet the processing and operating challenges required for use in electronic devices." In particular, they proved that "these molecules are stable under extremes of temperature (400°C) and large numbers of read-write cycles (1 trillion)."
That demonstrated stability, they conclude, "indicates that these molecular architectures can be readily adapted to current semiconductor fabrication technology and operated under the conditions required for a practical device."
By establishing the practicality of molecular memories, says Lindsey, the findings should help eliminate doubts about the role of organic materials in electronic devices.
"There is a perception that organic molecules are fragile," Lindsey said. "The critical question has been whether, given the high temperatures and other stresses of production and use, any molecule-based devices could meet functionality standards. I believe our research has laid this question to rest, and demonstrated that appropriately chosen molecules can readily function in practical devices."
That knowledge, he said, should speed development of molecule-based electronics, which promise smaller, faster and far more powerful computers and other applications.
The research was funded by ZettaCore Inc. and the Defense Advanced Research Projects Agency (DARPA) Moletronics Program. Bocian and Lindsey are co-founders of ZettaCore and serve as consultants for the company.
Note to editors: An abstract of the paper follows.
"Molecular Memories that Survive Silicon Device Processing and Real-World Operation"
Authors: David F. Bocian, Zhiming Liu, Amir A. Yasseri, University of California, Riverside; Jonathan S. Lindsey, North Carolina State University.
Published: Nov. 28, 2003, in Science.
Abstract: If molecular components are to be used as functional elements in place of the semiconductor-based devices present in conventional micro-circuitry, they must compete with semiconductors under the extreme conditions required for processing and operating practical devices. Herein, we demonstrate that porphyrin-based molecules bound to Si (100), which exhibit redox behavior useful for information storage, can meet this challenge. These molecular media in an inert atmosphere are stable under extremes of temperature (400° C) for extended periods (approaching 1 hour) and do not degrade under large numbers of read-write cycles (10¹²).
Further Media Contacts: Paul K. Mueller, News Services, 919-515-3470 | <urn:uuid:8d7255c2-fc01-4943-8e24-f1708141cee1> | CC-MAIN-2016-26 | http://www.eurekalert.org/pub_releases/2003-12/ncsu-mmo120203.php | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783400031.51/warc/CC-MAIN-20160624155000-00171-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.931664 | 863 | 3.609375 | 4 |
Twenty one Sikh soldiers who died in 1897 defending a small signalling post in Saragarhi, then in British India, will be remembered today by the Sikh community in Wolverhampton.
The soldiers have always been remembered for their courage and determination in defending their outpost from Afghan soldiers.
Their refusal to back down and surrender has been seen by the Sikh community as staying true to the words of the tenth Guru:
The efforts of the Sikh soldiers meant that British reinforcements could secure the area.
They were awarded the Indian Order of Merit after their deaths.
An exhibition about the battle and the Sikh faith is open to the public at the Sri Guru Teg Bahadur Gurdwara in Wolverhampton | <urn:uuid:83fbad20-2a8e-446f-b884-9b07160e6d68> | CC-MAIN-2016-26 | http://www.itv.com/news/central/2012-09-12/wreath-laying-for-sikhs-killed-in-battle/ | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783404826.94/warc/CC-MAIN-20160624155004-00044-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.974864 | 143 | 2.796875 | 3 |
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This toxic agent is found in many species of beans, but it is in highest concentration in red kidney beans (Phaseolus vulgaris). The unit of toxin measure is the hemagglutinating unit (hau). Raw kidney beans contain from 20,000 to 70,000 hau, while fully cooked beans contain from 200 to 400 hau. White kidney beans, another variety of Phaseolus vulgaris, contain about one-third the amount of toxin as the red variety; broad beans (Vicia faba) contain 5 to 10% the amount that red kidney beans contain.
As few as 4 or 5 beans can bring on symptoms. Onset of symptoms varies from between 1 to 3 hours. Onset is usually marked by extreme nausea, followed by vomiting, which may be very severe. Diarrhea develops somewhat later (from one to a few hours), and some persons report abdominal pain. Some persons have been hospitalized, but recovery is usually rapid (3 - 4 h after onset of symptoms) and spontaneous.
The syndrome is usually caused by the ingestion of raw, soaked kidney beans, either alone or in salads or casseroles. As few as four or five raw beans can trigger symptoms. Several outbreaks have been associated with "slow cookers" or crock pots, or in casseroles which had not reached a high enough internal temperature to destroy the glycoprotein lectin. It has been shown that heating to 80 degrees C. may potentiate the toxicity five-fold, so that these beans are more toxic than if eaten raw. In studies of casseroles cooked in slow cookers, internal temperatures often did not exceed 75 degrees C.
All persons, regardless of age or gender, appear to be equally susceptible; the severity is related only to the dose ingested.
Outbreaks in the U.K. are far more common, and may be attributed to greater use of dried kidney beans in the U.K., or better physician awareness and reporting.
The following procedure has been recommended by the PHLS (Public Health Laboratory Services, Colindale, U.K.) to render kidney, and other, beans safe for consumption:
* Soak in water for at least 5 hours.
* Pour away the water.
* Boil briskly in fresh water for at least 10 minutes.
* Undercooked beans may be more toxic than raw beans.
Sources: FDA (U.S. Food and Drug Administration) Center for Food Safety & Applied Nutrition.
BAD BUG BOOK (Foodborne Pathogenic Microorganisms and Natural Toxins Handbook).
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All contents are copyright © 1990 - 2016 James T. Ehler and www.FoodReference.com unless otherwise noted. All rights reserved.
You may copy and use portions of this website for non-commercial, personal use only.
Any other use of these materials without prior written authorization is not very nice and violates the copyright.
Please take the time to request permission. | <urn:uuid:36db7dd1-e980-4649-a444-9259f94eda00> | CC-MAIN-2016-26 | http://www.foodreference.com/html/artredkidneybeanpoisoning.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783395620.56/warc/CC-MAIN-20160624154955-00086-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.912142 | 730 | 2.984375 | 3 |
Zoo elephants have a very repetitive, boring lifestyle
A new study comparing wild, captive and working elephants has found that living in zoos can significantly shorten the animals' lives.
Writing in the journal Science, researchers say obesity is a major cause of death in adult zoo elephants.
They also cite stress as the key factor in the death of young captive animals when they are moved from zoo to zoo.
They say ideally zoos should not take on new elephants if they cannot provide suitable environments.
The study focused on the lives of female elephants, comparing more than 4,500 individuals. The researchers looked at wild elephants in Kenya's Ambosseli National Park, working elephants in the Burmese logging industry, and zoo elephant populations in Europe.
For African elephants, the average lifespan in captivity was only 19 years compared with 56 years in the wild.
Rates of mortality amongst zoo-born Asian elephants were two to three times higher than for those born in the logging camps.
Ros Clubb from Britain's Royal Society for the Prevention of Cruelty to Animals (RSPCA) says diet and lifestyle are the key factors influencing elephant lifespan in zoos.
"The vast majority are overweight in zoos, this could explain the high still-birth rates and why they're dying early. Bigger mothers have bigger calves and more of these are still-born," she said.
Wild elephants live in herds made up of family groups
Early death was also more likely to occur in captive animals born in the wild or transferred between zoos. Dr Clubb says this is probably caused by the stress of being taken away from their herd, mothers or family group.
"In the wild they live in large stable groups, separation does cause stress; we know this from studies of other species," she said.
Khyune Mar, now at the Department of Animal and Plant Sciences at Sheffield University, used to work for Myanma Timber Enterprise, the commercial arm of Burma's forest ministry.
The company uses elephants to haul logs from the forests. Analysis of the lives of these working Asian elephants was based on data Dr Mar collected in Burma.
She says their longer life expectancy - more than 40 years compared with less than 19 in zoo elephants - can be put down to their lifestyle; for half the time the Burmese working elephants are allowed to act naturally.
"We keep working elephants in the workforce for no more than six to eight hours a day. For the remaining hours we let them loose in the forest, they live like wild elephants, they can meet and mate with wild elephants, they have a full elephant life, good exercise and good food," she said.
Burmese logging elephants can roam free in the forest for some of the time
Dr Mar says there are lessons from the treatment of these working elephants that could be taken on board by zoos.
"They have a very monotonous lifestyle, every day is the same for zoo elephants, they have to live in the same compound, with limited roaming, this makes them more stressed," she said.
"They need a huge home range, more systematic enrichment, bigger compounds, grooming areas, mud wallows, hills."
She says its important to allow them the freedom to behave naturally and has a straightforward message for zoos.
"If the zoo does not have space, its simple - don't take elephants."
The report's authors say transfers of elephants between zoos should be avoided, calves should be kept with their mothers for as long as possible to avoid stress-related death, and there should be regular screening for signs of obesity.
A separate study looking in detail at all the elephants in UK zoos has found significant health problems and evidence of widespread psychological distress.
Researchers from Bristol University studied 77 animals in 13 zoos and found that almost half of the elephants displayed abnormal behaviour.
This included repeatedly swaying the trunk, pacing backwards and forwards and retracing their steps over and over again.
"Some of the animals were born in the zoos and must have developed it there," said Chris Sherwin, from Bristol University's Department of Veterinary Science.
"It's possibly their way of coping with stress, but almost certainly indicates they're in an environment which is inappropriate for their needs. This is not behaviour you see in the wild."
The report says unless the animals' health and psychological suffering can be addressed, the ethics of keeping elephants in zoos must be questioned.
"In my opinion, given the correct housing and care it would be ethically acceptable to keep a few elephants in a few zoos, but certainly not the numbers we have in all the zoos we have now," Dr Sherwin added.
The Zoos Forum, the UK government's independent advisers on zoos, will consider the new findings and report to the Department of Environment, Food and Rural Affairs (Defra) within six months. | <urn:uuid:b3084b99-4d75-438a-96c5-0c7ee2b0020f> | CC-MAIN-2016-26 | http://news.bbc.co.uk/2/hi/science/nature/7777413.stm | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783395346.6/warc/CC-MAIN-20160624154955-00056-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.964483 | 1,005 | 3.203125 | 3 |
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Assistive technology is used to describe devices and services that lessen or remove barriers faced by persons with disabilities. Although the term is contemporary, the use of assistive technology is not new. For centuries, individuals with disabilities have used a variety of assistive devices to help them overcome demands in the environment. Assistive technology can be simple to quite complex in nature. Many types of assistive technology are available on computers to assist in reading information, keyboarding, etc. DRES assists students by having technology on hand for them to try out. DRES also provides training to help students become more effective and efficient in their use of assistive technology.
Accessing Assistive Technology in University Labs
- On the desktop is a folder labeled "Accessiblity"
- Open this folder for shortcuts to assistive technology programs
ICS and Residence Hall Labs
- From the start menu select "Accessibility"
- Shortcuts to the assistive technology programs will appear underneath
Features of Accessible Workstation
- 21" or larger monitor with at least 1600x1200 resolution, the monitor can then be used in 800x600 mode essentially doubling the size of the content displayed
- Adjustable height workstation designed for a person using a wheelchair
- At least 19" from the front of the workstation with a width of at least 30" of clear floor space under the work surface for person in a wheelchair to move their wheelchair without obstruction.
- Adjustable work surface height from 28" to 34" from the top of the work surface to the floor
- Accessible route to accessible workstation
- At least 36" of clearance in front of the workstation for people to maneuver their wheelchair into the accessible workstation. Ideally more space should be provided for people using larger motorized wheelchairs and scooters.
- Routes form the entrance of the computer lab to the accessible workstations should be wide enough for a person in a wheelchair to get to the accessible workstation. This includes providing a minimum of 36" clearance in routes to the accessible workstations from the entrance, ideally there should be 48" of clearace to support people using large power wheelchiars and schooters.
- Accessible workstations in classrooms should be placed close to the instructor or the presentation screen to help students with visual impairments to see instructional materials and interact with the instructor.
- Kensginton trackball (optional)
Number of Workstations per Lab
- At least one accessible workstations for all labs and classrooms with computer workstations used by students
- At least two accessible workstations for labs and classrooms greater that 25 computer workstations | <urn:uuid:7f7b5f43-4abc-41c6-b1a9-fc7507fd55e1> | CC-MAIN-2016-26 | http://disability.illinois.edu/academic-support/assistive-technology | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783393463.1/warc/CC-MAIN-20160624154953-00083-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.921009 | 556 | 3.40625 | 3 |
Owners who want to better understand their canine companions must recognize that dogs
see the world from a different visual perspective. The differences begin with the structure of
the eye. "We have a good idea what canines see because we know the make-up of the
retina of a dog's eye," says Dr. Ralph Hamor, a veterinarian and specialist in ophthalmology
at the University of Illinois College of Veterinary Medicine Teaching Hospital.
The retina, which covers the back of the inside of the eyeball, contains cones and rods-two
types of light-sensitive cells. Cones provide color perception and detailed sight, while rods
detect motion and vision in dim light. Dogs, which have rod-dominated retinas, see better in
the dark than humans do and have motion-oriented vision. However, because they have
only about one-tenth the concentration of cones that humans have, dogs do not see colors
as humans do.
"I generally explain that dogs see like a color-blind human," says Dr. Hamor. "Many people
think that a person who is red/green color blind cannot see any color, but there are
variations of being color blind. Most people have vision that is trichromatic (three color
variations). People who are red/green color blind are dichromatic (two color variations).
Dogs can pick out two colors-blue-violet and yellow-and they can differentiate among
shades of gray." Dogs are unable to distinguish among green, yellow, orange, and red. They
also have difficulty differentiating greens and grays.
Dogs use other cues (such as smell, texture, brightness, and position) rather than rely on
color. Seeing-eye dogs, for example, may not distinguish whether a stoplight is green or
red; they look at the brightness and position of the light. This and the flow and noise of
traffic will tell the dog that it is the right time to cross the street. | <urn:uuid:ebd46000-9b9a-4dbb-a10e-d022ce63211e> | CC-MAIN-2016-26 | http://www.cavaliertalk.com/forums/showthread.php?10172-My-ruby-acting-differently&p=104465 | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783393997.50/warc/CC-MAIN-20160624154953-00070-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.936754 | 420 | 3.703125 | 4 |
The flu is a respiratory illness caused by the influenza virus. The flu is not the same as a cold, although they share many of the same symptoms. The cold is caused by a different virus, and it tends to have milder symptoms than the flu. Colds are also less likely to cause serious complications.
When the influenza virus gets into the body, it moves into the respiratory tract. Once there, it binds to the surface of cells. The virus then opens and releases its genetic information (RNA) into the cell's nucleus. The nucleus is where the cell's genetic information (DNA and RNA) is stored. The virus replicates, or copies itself, and takes over the functions of the cell. The copies of the virus move to the cell membrane until the cell finally dies and releases them out into the body, where they go on to infect other cells.
The respiratory tissues swell up and become inflamed (the inflammation usually heals within a few weeks). As the virus moves through the respiratory tract and into the bloodstream, the first symptoms begin to emerge. The replication process continues for up to several days, until the body's immune system begins to fight the virus off.
Flu symptoms can include any or all of the following:
- Body aches
- Runny nose and congestion
These symptoms, although uncomfortable, are generally not dangerous. But the flu also weakens the immune system, leaving it vulnerable to more serious infections. High-risk individuals (see Who Is at Risk?) in particular are susceptible to serious complications, such as:
- Bacterial pneumonia
- Sinus problems and ear infections (primarily in children)
- Worsening of preexisting conditions, such as asthma or diabetes | <urn:uuid:78a3ac43-d82a-478c-867a-e983ff710009> | CC-MAIN-2016-26 | http://science.howstuffworks.com/life/cellular-microscopic/flu1.htm | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783392099.27/warc/CC-MAIN-20160624154952-00030-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.944199 | 351 | 4.3125 | 4 |
When a person has become disrespected and is looked down upon, this is an example of degradation.
- a degrading or being degraded in rank, status, or condition
- a degraded condition
- Geol. the lowering of land surfaces by erosion
- R.C.Ch. laicization of a cleric, imposed as a penalty
Origin of degradationFrench dégradation ; from Late Latin degradatio ; from degradare: see degrade
- The act or process of degrading.
- The state of being degraded; degeneration.
- A decline to a lower condition, quality, or level.
- Geology A general lowering of the earth's surface by erosion or weathering.
- Chemistry Decomposition of a compound, especially complex substances such as polymers and proteins, by stages, exhibiting well-defined intermediate products.
- The act of reducing in rank, character, or reputation, or of abasing; a lowering from one's standing or rank in office or society; diminution; as, the degradation of a peer, a knight, a general, or a bishop.
- The state of being reduced in rank, character, or reputation; baseness; moral, physical, or intellectual degeneracy; disgrace; abasement; debasement.
- Diminution or reduction of strength, efficacy, or value; degeneration; deterioration.
- (geology) A gradual wearing down or wasting, as of rocks and banks, by the action of water, frost etc.
- A deleterious change in the chemical structure, physical properties or appearance of a material from natural or artificial exposure.
- The state or condition of a species or group which exhibits degraded forms; degeneration.
- Arrest of development, or degeneration of any organ, or of the body as a whole.
- The gradual breakdown of components of a material, as a result of a natural element, i.e.: heat, cold and wind.
From French dégradation | <urn:uuid:ba150d1c-9364-46ae-8ccb-65868bd646f4> | CC-MAIN-2016-26 | http://www.yourdictionary.com/degradation | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783396027.60/warc/CC-MAIN-20160624154956-00017-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.871292 | 411 | 3 | 3 |
For Immediate Release: Dec. 17, 2009
Media Contact: Communication Office
Vermont Department of Health
BURLINGTON – The Vermont Department of Health has been awarded more than $575,000 per year for five years by the Centers for Disease Control & Prevention (CDC) to strengthen the state’s ability to protect residents from environmental hazards.
The grant will build the capacity for the Departments of Health and Environmental Conservation to link environmental exposures with health outcomes. While scientists know exposures such as radon and lead contribute to illnesses, many environmental and health connections remain unproven since detailed health and environmental data were not integrated into a single web-based network.
“Environmental exposures can result in slow-developing, complex chronic diseases such as asthma or cancer,” said Health Commissioner Wendy Davis, MD. “These tracking data will improve our ability to protect the health of all Vermonters because it will help identify threats and reduce the amount of time it takes local and state health officials to respond.”
The network will allow health professionals, scientists, policymakers and other Vermonters to better understand where environmental hazards and illness are occurring. For example, tracking data will be used to further understand asthma, one of the most common chronic diseases among children.
According to the 2008 Asthma Plan, certain regions of Vermont have higher rates of hospitalization due to asthma than others. Tracking data will be used to identify trends and patterns in the occurrence of asthma. Differences between geographic areas may be the result of environmental exposures, such as particulate or ozone pollution; differences in characteristics of the underlying population; or variations in the diagnostic techniques used by hospitals.
By comparing these data with the incidence of asthma hospitalizations, or emergency room visits, the Health Department will be able to identify trends in age groups, time periods and geographic areas. Results could lead to better prevention strategies and policy changes.
The grant was awarded to Vermont as part of a national CDC initiative to improve access to environmental health information so that communities and families understand hazards and can make informed decisions about how to protect their health.
Vermont is one of only 22 states to be awarded an Environmental Public Health Tracking Network grant.
For more information on the grants visit: www.cdc.gov/ephtracking | <urn:uuid:f5b6196e-aaf7-4a2d-9367-dceebd4a243f> | CC-MAIN-2016-26 | http://www.healthvermont.gov/news/2009/121709envirohealth.aspx | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783402516.86/warc/CC-MAIN-20160624155002-00185-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.928966 | 466 | 2.609375 | 3 |
| Mount Everest: Under a microscope
Beijing, May 22 (PTI): A record 24 Chinese mountaineers and scientists today conquered Mount Everest, kicking off a state-of-the-art effort to re-measure the world’s highest peak and conduct the most comprehensive scientific studies on the effect of global warming in the Himalayan region.
The expedition, which spent 77 minutes at the top, scaled the earth’s highest peak and successfully performed measuring operations.
This is the second measurement endeavour undertaken by the Chinese in the past three decades. The first, in 1975, reported the height of the world’s top mountain at 8,848.13 metres above sea level.
The team erected a 2.5-metre-long survey beacon and established a global positioning system monitoring station there for height measurement in the next two days and in the future.
They also used a radar device to detect the thickness of the snow and ice coat of Mount Qomolangma (the Chinese name for Mount Everest), which straddles the border between China and Nepal.
The results will exclude the thickness of ice and snow capping the peak, the state-run Xinhua news agency reported.
If successful, the expedition will be the first to determine the location of the peak’s rock formation with the most advanced technology in the world, a researcher said.
He said radar technology can help researchers ascertain the height of the rock formation after subtracting the depth of snow and ice on the top of the peak from the whole.
Geological theory says Mount Everest, which was formed about 60 million years ago, is growing about 10 millimetres a year as a result of crustal upthrust in the Himalayas, but some researchers in recent years have contended that the summit is becoming shorter as it begins to subside.
The height of the peak has been a subject of controversy for decades. A survey by an American research team in 1999 put it at 8,850 metres.
“Results of the current measurement will provide important data for the study of crustal movement and for other geoscience studies,” said Chen Bangzhu, head of the state bureau of surveying and mapping. | <urn:uuid:23759876-98ea-4f2a-b4b7-65381a30f598> | CC-MAIN-2016-26 | http://www.telegraphindia.com/1050523/asp/foreign/story_4774716.asp | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783393997.50/warc/CC-MAIN-20160624154953-00010-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.928925 | 460 | 3.046875 | 3 |
An ecological comparison of two sympatric primates:Saguinus fuscicollis andCallicebus moloch of Amazonian Peru
- Janis Crandlemire-SaccoAffiliated withDepartment of Anthropology, University of Pittsburgh
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The ecologies of two sympatric primates,Saguinus fuscicollis andCallicebus moloch, were compared during a four-month field study in southeastern Peru in order to examine the mechanisms by which these primate frugivores minimize competition for food and space.Saguinus fuscicollis andCallicebus moloch were found to differ dramatically both in diet and in use of the shared habitat. Specifically, tamarins and titis showed very little overlap in their choices of food plants or animal foods and they used distinctive foraging styles, exploiting very different parts of the habitat for animal prey. Significant interspecific differences were found in the use of particular support structures and strata within the forest, and in the density of vegetation preferred. These results suggest that resource competition between saddle-backed tamarins and dusky titis is minimal, a fact that could account for the high frequency of free association between the two species and the benign nature of these interspecific contacts.
Key WordsEcology Diet Sympatry Competition Polyspecific groups
- An ecological comparison of two sympatric primates:Saguinus fuscicollis andCallicebus moloch of Amazonian Peru
Volume 29, Issue 4 , pp 465-475
- Cover Date
- Print ISSN
- Online ISSN
- Additional Links
- Polyspecific groups
- Author Affiliations
- 1. Department of Anthropology, University of Pittsburgh, 15260, Pittsburgh, Pennsylvania, U.S.A. | <urn:uuid:d95c7da2-f802-4c8b-a44e-7c01bcec3bb8> | CC-MAIN-2016-26 | http://link.springer.com/article/10.1007/BF02381134 | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783397567.28/warc/CC-MAIN-20160624154957-00092-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.862725 | 388 | 2.53125 | 3 |
1 Trans. A. S. C. E., December, 1893.
Concrete is used very largely for constructing retaining walls and bridge abutments. The foundations of a retaining wall should be of ample width, and if the wall is not founded on rock, some settlement and outward movement may be expected if the common formulas are used in computing the dimensions.
If this movement is not equal throughout the wall, cracking is likely to take place, and to confine these cracks to predetermined vertical planes, it is well to construct the wall, if a long one, with vertical joints at intervals of fifteen to thirty feet. Such a joint is made by building one section and following with another, without special precautions to make a bond between.
If there is an opportunity for water to accumulate, care should be taken to drain the earth back of the wall, either by drains leading around the ends, or by pipes passing through the wall. The latter may result in discoloration of the face.
The face of a retaining wall or abutment is preferably given a batter, and a coping is provided to improve the appearance. The coping should have a slight inclination toward the back to prevent the discoloration of the face by dripping. It should be divided by vertical joints into blocks, not more than six to eight feet in length. The projection of the coping will depend upon the dimensions of the wall. Wing walls are preferably built with a sloping top or coping, but this should be made monolithic with the wall by special molds (§729).
In the use of concrete for abutments and piers, the practice of the Illinois Central Railroad, as set forth in their specifications, can hardly be improved upon. The engineer of bridges and buildings on this road, Mr. H. W. Parkhurst, M. Am. Soc. C. E., is one of those engineers who early recognized the value of concrete in bridge work, and as the result of his extensive experience along this line, he is widely known as an able and conservative authority.
These specifications are printed nearly in full in Engineering News of July 18, 1901, from which the following extracts are made: —
Natural cement concrete "may be used where foundations are entirely submerged below low-water mark, or where there is no risk of the same being exposed to the action of the weather by cutting away the surrounding earth. It, however, shall be used only where a firm and uniform foundation is found to exist after excavations are completed. In all cases where foundations are liable to be exposed to the action of the water, or where the material in the bottom of excavations is soft or of unequal firmness, Portland cement concrete must be employed for foundation work.
"The natural cement concrete shall usually be made in the proportions (by measure) of one part of approved cement to two parts of sand and five parts of crushed stone, all of character as above specified. For Portland cement concrete foundations, one part of approved cement, three parts of sand and six parts of crushed stone may be used. Wherever in the judgment of the engineer or inspector in charge of the work, a stronger concrete is required than is above specified, the proportions of sand and crushed stone employed may be reduced, a natural cement concrete of 1,2 and 4, and a Portland cement concrete of 1, 2 and 5 being substituted for those above specified.
Concrete for the bodies of piers and abutments, for all wing-walls for same, and for the bench walls of arch culverts, shall generally be made in the proportions (by measure) of one part of cement, two and one-half parts of sand and six parts of crushed stone. Where special strength may be required for any of this work, concrete in the proportions of 1, 2 and 5 may be used; but all such cases shall be submitted to the judgment of the engineer of bridges, before any change from the usual specification is to be allowed.
"For arch rings of arch culverts and for parapet head walls and copings to same, Portland cement concrete, in proportions of 1, 2 and 5, shall generally be used. Concrete of these proportions shall also generally be used for parapet walls behind bridge seats of piers or abutments, and for the finished copings (if used) on wing-walls of concrete abutments, also for arch work in combination with I-beams or in combination with ironwork for transverse loading.
"Bridge seats of piers and abutments and copings of concrete masonry which are to carry pedestals for girders or longer spans of ironwork, shall generally be made of crushed granite and Portland cement, in the proportion (by measure) of one part of approved cement, two parts of fine granite screenings, and three parts of coarser granite screenings, the larger of which shall not exceed three-quarters inch in greatest dimension".
729. After specifying the method of building molds, which is treated elsewhere (Art. 62), the specifications proceed: —
"The planking forming the lining of the molds shall invariably be fastened to the studding in perfectly horizontal lines; the ends of these planks shall be neatly butted against each other, and the inner surface of the mold shall be as nearly as possible perfectly smooth, without crevices or offsets between the sides or ends of adjacent planks. Where planks are used a second time, they shall be thoroughly cleaned, and, if necessary, the sides and ends shall be freshly jointed so as to make a perfectly smooth finish to the concrete.
"The molds for projecting copings, bridge seats, parapet walls, and all finished work shall be constructed in a first-class workmanlike manner, and shall be thoroughly braced and tied together, dressed surfaces only being exposed to the contact of concrete, and these surfaces shall be soaped or oiled if necessary, so as to make a smoothly finished piece of work. The top surfaces of all bridge seats, parapets, etc., shall be made perfectly level, unless otherwise provided in the plans, and shall be finished with long, straight edges, and all beveled surfaces or washes shall be constructed in a true and uniform manner. Special care shall be taken in the construction of the vertical angles of the masonry, and where I-beams or other ironwork are not used in the same, small wooden strips shall be set in the corners of the mold, so as to cut off the corners at an angle of 45°, leaving a beveled face about one and one-half to two inches wide, instead of a right-angled corner.
"Where wing-walls are called for, which have slopes corresponding to the angle of repose of earth embankments, these slopes shall be finished in straight lines and surfaces, the mold for such wing-walls and slopes being constructed with its top at the proper slope, so that the concrete work on the slope maybe finished in short sections, say from three to four feet in length, and bonded into the concrete of the horizontal sections before the same shall be set, each short section of sloped surface being grooved with a cross-line separating it from adjacent sections. It will not be permitted to finish the top surface of such sloped wing-walls by plastering fresh concrete upon the top of concrete which has already set, but the finished work must be made each day as the horizontal layers are carried up, to accomplish which the mold must be constructed complete at the outset; or, if the wing-wall is very high, short sections of the mold, including the form for the slopes, must be completed as the horizontal planking is put in place".
730. This is followed by directions concerning foundation work; the following is given relative to building steel into the masonry: —
"Iron rails to be furnished by the railroad company shall be laid and imbedded in such manner as may be specified in such foundation concrete as in the opinion of the engineer of bridges needs such strengthening, and no extra charge, except the actual Cost of handling the same, shall be made by the contractor for such work, but the volume of such iron shall be estimated as concrete.
"Where I-beams are to be placed in the angles of concrete piers as a protection against ice, drift, etc., these shall be set up and securely held in position so that they will extend one foot or more into the foundation concrete. The planking of molds shall be fitted carefully to the projecting angles of these I-beams, and small fillets of wood shall be fitted in between the inner faces of the mold and the rounded edges of the I-beam flanges, so that no sharp projecting angle of concrete will be formed as the work is constructed.
"These fillets may be made in short pieces and fastened neatly into the mold as the layers of concrete are carried up. Such I-beams will generally be furnished of sufficient length to extend at least six inches above the top of the battered masonry into the concrete coping, and special pains shall be taken to tamp the concrete thoroughly around the I-beams, and to finish the coping above and around the ends of the same, so as to make a compact and solid bearing against the ironwork.
"Where anchor bolts for bridge-seat castings are required, they shall be set in place and held firmly as to position and elevation, by templets, securely fastened to the mold and framing. Such I-beams and anchor bolts shall be imbedded in the concrete work without additional expense beyond the price to be paid per yard for the several classes of concrete in which such iron is placed, the volume of iron being estimated as concrete.
"After the work is finished and thoroughly set, all molds shall be removed by the contractor. They shall generally be allowed to stand not less than forty-eight hours after the last concrete work shall have been done. In cold weather, molds shall be allowed to stand a longer period before being removed, depending upon the degree of cold. No molds shall be removed in freezing weather, nor until after the concrete shall have had at least forty-eight hours, with the thermometer at or above 40° Fahr., in which to set".
"Layers of concrete shall be kept truly horizontal, and if, for any reason, it is necessary to stop work for an indefinite period, it shall be the duty of the inspector and of the contractor to see that the top surface of the concrete is properly finished, so that nothing but a horizontal line shall show on the face of the concrete, as the joint between portions of the work constructed before and after such period of delay. If for any reason it is impossible to complete an entire layer, the end of the layer shall be made square and true by the use of a temporary plank partition. No irregular, wavy or sloping lines shall be permitted to show on the face of the concrete work as the result of constructing different portions of the work at different periods, and none but horizontal or vertical lines shall be permitted in such cases". | <urn:uuid:8eaa40d6-02ed-4aa3-a313-6c9afd3ff922> | CC-MAIN-2016-26 | http://bookdome.com/science/Cement-Concrete/Special-Uses-Of-Concrete-Continued-Bridges-Dams-Locks-And-Breakwaters-Art.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783399117.38/warc/CC-MAIN-20160624154959-00172-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.952775 | 2,287 | 3.046875 | 3 |
Peter Convey of the British Antarctic Survey and colleagues from the University of Reading reported the growth of Antarctic moss that had been frozen for 1,500 years in the March, 17, 2014, issue of the journal Current Biology.
This discovery is the oldest known natural revitalization of any plant. The researchers only brought the moss to the surface of the Earth and exposed the moss to light and air. Revitalization of plants has been seen in plants that were frozen for 20 years but no plant of this age has ever been known to begin to grow before now.
The moss was extracted from core samples taken from Signy Island in the South Orkney Islands of Antarctica. The moss banks of Signy Island are over 6,000 years old.
The discovery indicates that moss survived the multiple freezing and thawing events of the last 6,000 years and probably for thousands of years before.
The regeneration of moss that had been frozen for 1,500 years provides hope that the receding ice in the Antarctic and Arctic regions of the Earth may produce a new plant source that could mitigate some of the carbon dioxide produced by man. Mosses store and fix carbon and may act as a carbon sink in the future. | <urn:uuid:540c4f9e-4e49-4d74-8a4a-5290d70e1721> | CC-MAIN-2016-26 | http://www.examiner.com/article/antarctic-moss-comes-back-to-life-after-1-500-years | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783403826.29/warc/CC-MAIN-20160624155003-00069-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.966228 | 246 | 3.671875 | 4 |
How is a rainbow formed? Understand The Formation of Rainbow
When we look at a rainbow, we are reminded of hope. A hope that even at the end of a rainy day, a beautiful and colourful light symbolising happiness emerges. It is a truly wonderful sight to witness. It is also a source of amusement to children as they hear tales of a pot of gold at the end of the rainbow. But at the end it is just another marvel of physics. It can be explained through optics. “Optics” is a branch of physics that studies the properties of light. There are three different hypotheses on the mode of propagation of light. The three modes are wave propagation, through straight lines or rays and in the form of energy particles called photons. These modes of propagation were proposed to explain the different theories and properties of light.
“Visible light” is a part of the electromagnetic spectrum with a wavelength falling between UV rays and Infrared rays. Visible light itself is further sub divided into different colours at different wavelengths which ranges from red with the shortest wavelength to violet with longest wavelength. These are the rainbow colours in order which we notice while looking at it. A rainbow is a multi coloured arc formed with the order of colours being R (Red), O (Orange), Y (Yellow), G (Green), B (Blue), I (Indigo) and V (Violet) from top to bottom. There are three properties of light in play when we observe a rainbow. In its correct order of occurrence, they are: Refraction, dispersion of light and Total Internal Reflection. To explain the linked mechanism of all these properties, light is considered to travel as a ray (straight line propagation of light). Let us study the formation of a rainbow part by part while understanding each property.
Formation of Rainbow
Formation of Rainbow Step 1 – Refraction:
What is Refraction? – When light passes from one medium to another possessing different density the light ray bends at an angle. When the light passes from a rarer medium to a denser medium the light bends towards the normal to the surface of the second medium and away from normal while passing from a denser medium to a rarer medium. We can observe this when we see through a swimming pool. The floor appears to be higher than it actually is. The light rays coming from the floor to the eye go through a change of medium from water (denser) to air (rarer) and hence appears to be higher.
Refraction of Sunlight – So in the case of a rainbow formation, the light comes from the sun which passes through suspended water droplets. Here the sunlight is passing from a rarer medium (air) to a denser medium (water).
Formation of Rainbow Step 2 – Dispersion:
What is Dispersion? – White light consists of lights of seven different monochrome rays each of which has its own wavelength. So, when white light undergoes refraction, each colour bends at a different angle causing the splitting of the light depending on its wavelength. The difference between the angles of deviation is very small. So when theses split lines undergo refraction again, the angle difference increases and the colours are more noticeable. Therefore during dispersion white light is split up into its constituent colours.
Dispersion of Refracted Sunlight:
After the refraction has occurred from the rain drop, the white light from the sun undergoes dispersion and splits into its constituent colours. The red light undergoes the leastdeviation from the incident light which causes its formation on the top while violet undergoes the highest deviation to get a bottom spot.
Formation of Rainbow Step 3 – Total Internal Reflection:
What is Total Internal Reflection? – Total internal reflection occurs when a light ray passes from a denser medium to a rarer medium. When the incident angle of light on the boundary of the denser medium is more than a particular angle called the “Critical Angle” of that medium, then the light ray gets reflected back rather than being refracted. The optic fibres that we use in our homes for telephone lines, cable lines and broadband lines use this principle to transmit signals through long distances and with minimal signal loss. We can even observe this property by taking a plane piece of glass. First we must look at it normal to its surface and gradually increase the angle. After a particular angle, we notice that the glass starts to act like a mirror, no longer enabling us to see beyond it.
Total Internal Reflection of Light Rays Inside Water Droplets
The dispersed beams of white light get refracted through the first surface of the water droplet. When they are incident on the second surface (outer surface) with an angle more than the critical angle, the rays undergo total internal reflection and bounce back to the first surface and again undergo refraction and finally reach the eyes of the observer.
Putting the pieces together
On the other hand, Rainbows are also formed at the end of a waterfall at the place where the fine mist is present. To witness a rainbow, a bright sunlight, suspended water particles and the proper angle of viewing are essential. We can observe a rainbow when our back is faced towards the sun, there are suspended water particles in the air in front of us and that the angle of the water particles and our eyes is between 40 and 44 degrees.
Rainbows are actually formed in circular shapes. We generally see an arc shaped rainbow because of the presence of the ground since the suspended water particles are no longer present. Rainbows which are witnessed from aircrafts are observed to be in full circles since the angle is such that the suspended water particles are below us. But why do rainbows take a circular shape rather than the entire sky getting coloured up?
The angle difference between the ends of the rainbow (Violet and Red) is approximately two degrees i.e., the red light is deviated to an angle of 42 degrees from the incident angle of white light and violet light is deviated by an angle of 40 degrees. This deviation occurs at the suspended water particles that are at the correct angle ofviewing. Since every point is equidistant from the centre of a circle, the locus of the rainbow formed takes shape of a circle. All the suspended water particles that cause this angle of deviation are present on this circular locus with the observer being at the centre. | <urn:uuid:190d3ca4-a9c6-4321-89be-a44008b52811> | CC-MAIN-2016-26 | http://readanddigest.com/how-is-a-rainbow-formed/ | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783396027.60/warc/CC-MAIN-20160624154956-00013-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.937259 | 1,309 | 3.953125 | 4 |
"Water and Wires: Flood Control and Electrification in the
Lower Colorado River Valley"
L. Patrick Hughes
Rivers and Dreams
Since the dawn of time, rivers have been magnets for mankind. Human civilization first sprang up along the banks of major tributaries. Ancient Mesopotamia thrived between the Tigris and Euphrates while the Egyptian world centered around the Nile. The attraction continued through the centuries. London on the Thames, Paris on the Seine, Rome on the Tiber. Again and again the process of settlement repeated itself. It was no different on the other side of the Atlantic. Americans, even before the revolution that brought nationhood, situated themselves in ever-larger numbers alongside the waterways: New York on the Hudson, Boston on the Charles, Philadelphia on the Delaware. In the middle of the continent, New Orleans, Baton Rouge, Memphis, and St. Louis straddled the Mississippi. Pittsburgh, Cincinnati, and Louisville along the Ohio; Kansas City and Omaha along the Missouri. The list of examples is virtually endless.
Practicality underlay the demographic phenomenon. A good, navigable river was essential as a cheap and reliable means of transporting goods and people. The river connected settlers with the rest of the world, allowing the importation of goods necessary for survival while simultaneously enabling the exportation of raw materials and finished products to distant markets around the world. Secondly, the river was the municipal reservoir for residents, the source of drinking water for urban dwellers and life-giving liquid for irrigated agriculture. Finally, the flow of water was a cheap source of power to run machinery. Long before electricity, waterpower ran the world's manufacturing equipment.
Texans through time have been no less drawn to rivers than their ancestors on every continent of the globe. Reasons didn't change, only the names of the towns and tributaries. Spanish Texas featured Bexar and La Bahia along the San Antonio. El Paso del Norte, Albuquerque, and Santa Fe flourished along the Rio Grande. When settlers from the United States began to flood into Mexican Texas under the empressario program of Stephen F. Austin, they sank their roots - almost by second nature - in the rich soil between the Brazos and Colorado. Through the decades the fascination has endured. Houstonians seized the opportunity early in the twentieth century to become a great inland port facility by dredging out the Houston Ship Channel to connect their thriving metropolis with the Gulf of Mexico. Residents of Dallas even to this day and time periodically talk about dredging out the Trinity in order to allow vessels to travel hundreds of miles from the coast up to the Metroplex.
Along with the beautiful landscape and central location in the vast Republic of Texas, Austin or Waterloo, as it was originally known, came about in large part because of the Colorado River. It held out the potential of a transportation route to the Gulf coast, a reliable reservoir of drinking water, and the means to power machinery. City leaders dreamed big. Austin would simultaneously be the seat of government for the new nation and then state, an inland port, and a great manufacturing center.
Flaws in this sweeping vision, however, quickly became apparent. The Colorado proved too shallow to accommodate vessels of any real size. More importantly, highly variable rainfall patterns and topography combined to create two seemingly totally different rivers. The Colorado would all but dry up in periods of extended drought. But when heavy downpours blanketed the Hill Country west of town, the river became a raging torrent leaving physical destruction and loss of life in its wake. Situated along the Balcones Fault at the edge of the Edwards Plateau, the area was particularly prone to flooding. Precipitation raced off the limestone uplift into narrow channels - the Llano, the San Saba, the Pedernales, and others - before hitting the Colorado. The immense watershed channeled all the moisture towards Austin where it spread out after meeting the flatter land to the east.
Repeated attempts to corral the Colorado proved futile. The original Austin Dam, a hydroelectric structure completed in 1893, fell victim to floodwaters on April 6, 1900. Rebuilt in 1913, the dam failed yet again just two years later when monsoon-like thunderstorms inundated the Hill Country. Despite the investment of much money and even more energy, the dreams of Austinites lay dashed. The lesson of such efforts was clear; a single structure was insufficient to the task. If the potential benefits of the Colorado were ever to be realized, a whole series of hydroelectric dams would have to be constructed. Such a massive undertaking lay beyond the financial resources of the capital city.
Living in an Earlier Century
Farmers and ranchers just outside city limits had yet another problem. Like ninety-five percent of their brethren in rural America, they lived their lives without the modern conveniences of the electricity which urbanites in the United States had enjoyed for decades. Privately owned utility companies refused to provide such service, maintaining that rural electrification would be prohibitively expensive. There were simply too few people spread across too vast an area. The costs of constructing a distribution system under such circumstances would be astronomical. Sales of electricity to farmers and ranchers could never justify the expenditure of such sums. While government studies revealed that rural service would in the long run be profitable, private enterprise refused to move. As a result, those outside of urban areas such as Austin lived a lifestyle little different from that of their forefathers in the nineteenth century.
Running water was impossible without electricity. Hill Country residents, therefore, depended upon water wells for their needs. By their thirties, women had stooped shoulders from hoisting four gallon buckets of well water weighing thirty-two pounds apiece up from average depths of fifty to one hundred feet. And everything, whether for house or field, required water. The average rural family in Central Texas went through two hundred gallons of water a day - 73,000 gallons a year (weighing 300 tons).
Clothes washing - over wood fires in the yard - was a chore for the beginning of the week. Only with tremendous physical exertion could clothes be kept clean. After filling # 3 zinc washtubs with water from the well, wives manually agitated clothes with a broomstick, scrubbed apparel by hand using lye soap, and moved each piece from tub to tub using a pole. Four to eight loads of wash a week took endless hours of labor.
Without electricity, housewives pressed clothes using six to seven pound wedges of iron heated atop wood-burning stoves. "Sad irons" were unwieldy and required near continuous cleaning to avoid smearing soot on shirts and dresses. The heat could be withering in the dead of August in homes with neither fans nor air conditioning.
No electricity meant the refrigeration of food was difficult. Instead of a modern refrigerator, food was placed in an insulated wooden box holding twenty-pound blocks of ice hauled in from the nearest ice plant. Without refrigeration, families' survival during the winter months between growing seasons depended on the canning of vegetables, fruits, etc. Vegetables from the garden and fruit from the orchard had to be canned as it came ripe, day after day, week after week, month after month from late spring to late autumn. Water had to be hauled from the well, wood carried in to stoke the stove, and the tray for wood ashes constantly emptied.
Without electrical service, it is no exaggeration to say that Hill Country farmers and ranchers just west of Austin were trapped in an earlier time. It might be the third decade of the twentieth century for urbanites but it looked an awful lot like the mid-1880s when one motored past city limits.
Bad Times Bring Possible Solutions
Austinites and Central Texans had by the 1930s found no solutions to the dual problems of periodic flooding of the Colorado and the absence of electrical service. Only with the advent of Franklin Roosevelt's New Deal program to cope with the worst economic depression in all of American history did the means for successful action emerge. Those solutions lay not in Texas but Washington, D. C.
The Tennessee Valley Authority (TVA), launched in Roosevelt's first months in office, was the fulfillment of conservationists' dreams dating back to the Progressive era. Any number of river systems across the continent, including the Tennessee, lay uncontrolled and undeveloped. They suffered a variety of problems - flooding, soil erosion, grinding poverty, etc. Conservationists looked upon this as a needless and tragic waste of the nation's natural resources. If hydroelectric dams could be constructed in an orderly and systematic fashion in such watersheds, flooding could be controlled, soil erosion minimized, reservoirs created which would be a hedge against drought, and electric power produced and marketed on a non-profit basis in rural areas to transform people's lives. Proposals for the federal government to undertake such a program produced howls of protest from private utility companies about socialism and unfair competition with the business sector. Their opposition and the scope of such proposed undertakings stalled authorization.
Only when Americans demanded a full-blown government effort to end the Great Depression by whatever means necessary were such objections overcome. At Roosevelt's behest, Congress authorized and funded TVA as a multi-purpose effort to systematically develop natural resources in the Tennessee River valley. The federal government would pay for the construction and operation of an entire series of hydroelectric dams. Not only would flooding and soil erosion be brought under control, unemployed residents of the watershed would be given jobs, cash pumped into the deflated regional economy, and cheap electricity made available to rural Americans historically neglected by private utility companies.
Looking at these developments in the nation's capital, a group of Central Texans saw the TVA initiative as a blueprint for resolving similar problems in the Lone Star State. After years of hard work, influential Austin attorney Alvin J. Wirtz convinced the Texas legislature in 1934 to create the Lower Colorado River Authority (LCRA) as an independent state agency to develop the water resources of the river system. The state, however, lacked the financial ability at the depths of the Great Depression to fund the agency it had just created. Money to tame the river would have to be found elsewhere. Thus, Wirtz and others looked to Washington, D. C.
If Roosevelt's New Deal provided the model for the LCRA, it now extended the funds necessary to make it reality. LCRA directors applied to Harold Ickes and the Public Works Administration (PWA) for the money it could find nowhere else. Launched during the Hundred Days of 1933, PWA attacked the depression by lending or granting money to other governmental entities across the nation for construction projects, thereby reducing unemployment and attacking deflation. Competition for such monies was, however, extremely keen in a country devastated by economic disaster.
Luckily, the LCRA benefited from the tremendous political muscle exercised by Texans in the nation's capital. Such influence was critical in securing the financing to dam the Colorado. John Nance Garner of Uvalde was both vice president of the United States and FDR's invaluable liaison to Congress. Jesse Jones of Houston served as the nation's banker as head of the Reconstruction Finance Corporation. The Texas congressional delegation was perhaps the most influential on Capitol Hill, chairing no fewer than twelve committees through which all New Deal legislation had to pass. Perhaps most important for the LCRA were James P. Buchanan of Brenham who served as chair of the House Appropriations Committee and Joseph J. Mansfield of Columbus who chaired the House Committee on Rivers and Reservoirs. Buchanan, pivotal to Roosevelt's success, intervened successfully with the president to overcome PWA resistance to expending funds on the Colorado River project. Before completion in the early 1940s, Ickes and the PWA would authorize tens of millions of federal dollars for Central Texas.
Creation of the Highland Lakes System
Acquisition of a half-finished privately financed structure outside Burnet represented the new river authority's first order of business. Samuel Insull's gigantic utility combine had undertaken construction of Hamilton Dam in 1931. The collapse of the Insull empire the following year caused work to be halted after an expenditure of $3.5 million. The half-completed dam seemed an appropriate place to start. Congressman Buchanan intervened with President Roosevelt, securing a $4.5 million loan from the PWA to purchase the structure and resume construction. Before completion in 1937, the price tag for Hamilton Dam, subsequently renamed to honor Representative Buchanan, rose to $10.4 million. The undertaking proved two thousand jobs at the depths of the depression and proved an economic godsend for the people of Burnet and surrounding counties.
Buchanan by itself was nonetheless insufficient to conquer the flooding problem. While it could "help" constrain the river in times of rampage, Buchanan existed primarily to create a massive reservoir and generate electricity. As the City of Austin's earlier efforts demonstrated, one dam was insufficient to tame the Colorado. Only a series of dams could accomplish the objectives. Therefore, a much larger dam would have to be built downstream.
That structure, located in western Travis County at a historic crossing on the Colorado known as Marshall Ford, would be incredibly expensive. Fearing that Ickes and the PWA would not provide that much money, LCRA and Buchanan developed a two-phase strategy. They would get the appropriation for a "low dam" in order to get started and would subsequently seek additional funds to build the upper portion of the dam without which the whole function of flood control would be unattainable.
It was a tremendous gamble and one that seemed to backfire when Buchanan died unexpectedly. The river authority had lost its most important champion in budgetary battles. The low dam was well underway but unless elevated could not be the flood control lynchpin of the Highland Lakes system. Fate, however, intervened. Enter Lyndon Johnson, who won the special election to fill Buchanan's seat by endorsing the president's highly controversial court packing scheme. Having triumphed by championing the president's cause, Johnson became FDR's fair-haired boy. Word went out within the administration that LBJ was to be rewarded in every way possible. He received deferential treatment from Harold Ickes and the PWA that no freshman congressman could ever have expected. The necessary additional funding was quickly approved.
The cost for the dam at Marshall Ford, later renamed in honor of Congressman Mansfield, grew to a staggering $29 million. Subsequent lobbying by Representative Johnson resulted in LCRA having to repay but $5 million of that total; the rest was converted into an outright grant from the federal government. Over two thousand Central Texans found employment on the construction project which, in conjunction with other LCRA dams, finally tamed the Colorado. Every time a deluge inundates the Hill Country, Austinites give thanks for Mansfield Dam. One example must suffice. When floodwaters raced down the watershed in 1954, Lake Travis rose fifty-four feet in twelve hours! The devastation such waters would have caused in and below Austin boggle the mind.
Structural and political problems remained regarding Austin's inoperable dam, which had lain in ruin since the flood of 1915. The City of Austin, which owned its utility system and used the revenue it generated to keep property taxes down, wanted the dam rebuilt but failed to convince Ickes to bankroll the project. The stubborn Ickes refused to lend funds to another governmental entity that would be in competition with the river authority as a supplier of electricity. Such competition would hamper LCRA's ability to repay its PWA debts. He demanded the city give or sell the dam to the authority. Equally adamant, Mayor Tom Miller balked because lower electric revenues would drive up property taxes. LCRA refused to expend its funds rebuilding a dam it neither owner nor controlled.
Central Texas's new congressman miraculously worked out a deal acceptable to all parties. The City of Austin would rent the dam to the authority for fifty years and accept electricity from the reconstructed facility as rental compensation. LCRA had a long-term lease on the dam and avoided competition with the city. Once the river authority secured control of the structure, Ickes relented under pressure from Johnson and lent the $2.3 million required for reconstruction, which was completed in 1940.
Over the years LCRA constructed additional flood control structures to complete the Highland Lakes chain. Construction costs eventually totaled $72.4 million. The effort, however, provided five thousand jobs and pumped desperately needed cash into the entire region throughout the latter years of the Depression. According to long-time chamber of commerce president Walter E. Long, corralling the Colorado was "the major factor having to do with the growth of Austin."
Wires Across the Countryside
While the LCRA initiative at long last dealt successfully with flooding throughout the watershed, the task of rural electrification remained. The dams up and down the Colorado would shortly begin generating cheap public power. That power would benefit rural Central Texans little without a massive transmission and distribution network. Such a grid would be both difficult and expensive to construct. Only with such an undertaking, however, would the twentieth century finally dawn across the limestone plateau ranches to the west and the fertile blackland farms to the east of Austin.
The river authority lacked authorization under its charter from the state to construct any transmission and distribution system. As far as the legislature had been concerned, the production of public power had been at best a tangential consideration. LCRA's foremost mission was flood control and every penny it could put its hands on was committed to the erection of dams. Nonetheless, the river authority's financial viability depended upon the resolution of this problem. Only from the sell of the electricity it would soon be generating could it generate the revenue required to repay its debts to the PWA in Washington, D. C. Without such sales to farmers, ranchers, and cities throughout its service area, loan default was inevitable. The entire undertaking would collapse. Lyndon Johnson, Alvin Wirtz, and others ramrodding the LCRA were determined to prevent such a nightmare at all cost. Once again, the solution lay not in Austin but in the nation's capital.
As part of the Second New Deal to reverse the depression, Franklin Roosevelt launched the Rural Electrification Administration (REA) in 1935 to enable rural Americans across the country to obtain the life-transforming benefits of electricity for the first time. In the best of economic times, farmers and ranchers lacked the financial ability to generate, transmit, and distribute power. Their inability was even more pronounced at the depths of the worst depression in the nation's history. Therefore, REA would attack the problem by lending rural dwellers who banded themselves into economic cooperatives the funds necessary to obtain electricity. Such monies would be repaid to the government over a thirty-year time span with a minimal rate of interest. A family's financial liability was limited to the $5 membership fee to join the cooperative; it was technically the cooperative which borrowed the funds from REA and was legally responsible for repayment.
With necessary funding to complete construction of the authority's hydroelectric dams secured from the PWA, Congressman Johnson, Alvin Wirtz, and others who had been instrumental in the LCRA endeavor now undertook the task of convincing Central Texas to form cooperatives and apply for funds from the REA. Farmers and ranchers, leery of going into debt and risking their property to foreclosure, must be persuaded that their liability was limited to their membership fee. Publicity campaigns throughout the region slowly converted those dubious of the benefits of electrification or of the program's practicality. The Pedernales, Bluebonnet, and other rural cooperatives resulted. Additionally, cities such as Bastrop, Smithville, Elgin, Brenham, and others abandoned private suppliers and signed on with LCRA once guaranteed that rates would fall and service would improve. Loans totaling millions of dollars from the REA followed shortly thereafter. Utility poles began sprouting across the countryside, holding aloft the transmission lines connecting the dams to Central Texas farms and ranches.
The long-delayed dreams had finally
become reality and Central Texas would never again be the same.
John A. Adams, Jr., Damming The Colorado: The Rise of the Lower Colorado River Authority, 1933-1939, Texas A & M University Press (College Station: 1990).
Jimmy Banks and John E. Babcock, Corralling The Colorado: The First Fifty Years of the Lower Colorado River Authority, Eakin Press (Austin: 1988).
Walter E. Long, Flood To Faucet,
Steck Co. (Austin, 1956).
© L. Patrick Hughes, 1999 | <urn:uuid:7564ed25-c590-4a1a-b0bc-fbd790ebc629> | CC-MAIN-2016-26 | http://www2.austin.cc.tx.us/lpatrick/his1693/lcra.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783398869.97/warc/CC-MAIN-20160624154958-00103-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.957709 | 4,231 | 3.078125 | 3 |
Our ancestors lived consciously with nature, recognizing the interplay of things seen and unseen. They used various techniques, including sound, dance and darkness, to access the hidden realms, in search of wisdom, guidance, healing. Today, these mystical techniques have become recognized once again under the practice of shamanism.
Shamanism is a mystical, earth-centered practice rooted in an animistic world-view. A shaman, or shamanic practitioner, is someone who consciously and willingly enters an altered state to access other realms of existence for a specific purpose. She/he can be said to `walk between the worlds' to restore harmony and facilitate healing. The shaman's path is one of direct, personal experience of the Great Divine, the Otherworld, Spirit. It is a path that brings knowledge and the potential for personal transformation through co-creative action with the Sacred.
While the word shaman comes from the Tungus culture of Siberia, every culture had, and has, its own mystical practices, and commonalities of both techniques and beliefs exist across cultures. For example, shamanic practitioners believe in the existence of alternate realities, as well as beings that inhabit those realms. They believe in a divine force that ensouls everything, thereby giving life and consciousness to everything that exists. Shamanic practitioners view all things as being interconnected, a part of a universal network or web.
Techniques for accessing the Otherworld vary from culture to culture. However, each tradition uses some form of the shamanic journey, in which the shamanic practitioner willingly shifts her/his consciousness and voyages into the Otherworld. This technique forms the cornerstone of any shamanic practice. Once a practitioner begins using shamanic journey techniques to interact with the Otherworld, her/his personal, mystical cosmology activates to shape the co-creative process that unfolds, making shamanism a deeply personal practice.
Celtic shamanism is one form of shamanism that continues to call people to circles. As diverse as the Celtic peoples, Celtic shamanism remains firmly rooted in the mystical traditions of its forebears. With their profound reverence for the earth, practitioners of Celtic shamanism call to and work closely with the elements, seeking a path of harmony with nature. Celtic shamans view this reality as interwoven with the Otherworld without separation; therefore, they work with the thin places, recognizing that what happens in one realm affects the other in the never-ending spiral of life. Celtic shamanism ultimately encourages practitioners to walk between the worlds to align themselves with and thereby manifest the harmony of the Sacred Three in the natural, co-creative process of living. As a practitioner of Celtic shamanism, this philosophy flows behind and through my practice and teaching. | <urn:uuid:4c67180f-62c8-43de-9cf9-27ed248af65d> | CC-MAIN-2016-26 | http://www.circleofhealingarts.net/shamanism.htm | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783408840.13/warc/CC-MAIN-20160624155008-00131-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.939071 | 553 | 2.734375 | 3 |
1 [mass noun] The action of collecting water, especially the collection of rainfall over a natural drainage area: water catchment continues the whole year round
Más ejemplos en oraciones
- Maasai have complained that settlement in the drought-prone area by Kipsigis has harmed water catchment for the Ewaso Nyiro river, which the Maasai use to water their cattle.
- Since we were unable to reach the villages upstream, we cannot establish whether the river had water catchment or storage facilities upstream.
- My job was to assess the water flows and catchment yields of these various areas, so I know them well.
2A catchment area.
Oraciones de ejemplo
- If the latter was the case, there could be a higher risk of winter flooding in a number of the region's river catchments.
- It suggested that 20 catchments / regions highly affected by salinity be addressed first.
- The Tararua Forest Park protects mountain landscapes, considerable tracts of indigenous forests and the upper catchments of many rivers.
For editors and proofreaders
Saltos de línea: catch|ment
Definición de catchment en:
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Marilyn Hawley of the Materials Science and Technology Division is exploring a novel "bottom-up" fabrication approach to using a scanning tunneling microscope to create a solid-state, silicon-based, quantum computer. The approach involves the fabrication of atoms in a spin array, which could be the functional basis of a quantum computer.
Toni Taylor is a physicist working in the Laboratory's Materials Science and Technology Division. Taylor is interested in the ways in which ultrafast optical pulses of light might be used to selectively excite such complex materials systems as nonlinear optical crystals, semiconductor quantum dots, and bulk materials, in order to prepare and manipulate specific electronic and photonic quantum states which may be of critical importance for building future quantum electronic and photonic devices.
Coherent control of quantum mechanical states can provide qualitatively new modes of computation and communication. The methods to experimentally manipulate quantum states are well established for isolated atoms and molecules.
Coherent Quantum Control
The field of coherent quantum control in condensed-matter systems remains relatively untouched, yet the ability to coherently manipulate solids is of critical importance for building future quantum information devices. We are developing methods to coherently prepare and manipulate and interrogate quantum states in condensed matter systems using several complementary classes of excitations such as electron spins in solids, excitons in semiconductor quantum dots, vibrational states in molecular crystals, and surface plasmons in metal nanostructures.
Areas of Interest | <urn:uuid:baec952b-5ced-49d7-a2f7-48d9d46be52f> | CC-MAIN-2016-26 | http://www.lanl.gov/science/centers/quantum/cond_matter.shtml | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783392159.3/warc/CC-MAIN-20160624154952-00134-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.882709 | 298 | 2.6875 | 3 |
Fires, diesel-burning power generators, trucks and ships — they've all got something in common: That's their ability to generate soot in the Arctic, which accounts for as much as 30 per cent of the warming in the region.
"It's an Arctic problem," says Andreas Stohl from the Norwegian Institute for Air Research at last week's Arctic climate change and pollution conference in Copenhagen.
Finding ways to limit soot production in the Arctic is likely to be on the agenda of this week's Arctic Council meeting in Nuuk, Greenland.
That's because the Arctic nations, including Canada, the United States, Denmark, Norway, Sweden and Finland, can curb some Arctic warming simply by reducing soot in the Arctic.
And that will provide the Arctic some relief from rising temperatures, while the world's nations take their time on reaching an agreement to slash greenhouse gas emissions.
"It wouldn't solve the issue of climate change," Stohl told Nunatsiaq News. "But you can still do something."
For example, the shipping industry could retrofit its vessels with "relatively cheap" exhaust filters to catch tiny airborne soot particles; Arctic communities could also look at other ways to generate electricity than diesel-burning generators and turn to incineration instead of open burning to dispose of trash.
"It could make a difference," Stohl said. "If you're careful, it could reduce the local impact."
Locally, these efforts would "dramatically" reduce soot, Stohl said — and these efforts could cut down on warming in the Arctic, particularly around communities that may not realize how much soot contributes to heating up the lands and waters in the Arctic.
It could be possible to reduce Arctic warming, if these local causes of heat are reduced, Stohl said.
The impact of soot on the climate doesn't last as long as the warming from greenhouse gas emissions — only up to a month at most.
But soot which originates in the Arctic has a powerful, "very, very important" impact, Stohl said.
With shipping and cruises expected to increase in the region and spew out more soot, there's an urgency to act on soot reduction, he said.
Ships, open burns and anything that runs on diesel fuel are the major producers of soot in the Arctic.
But other major producers of soot within the Arctic include gas and oil burning at natural gas plants and wells or along pipelines.
Reducing the level of soot in the air could also improve human health, because soot particles are known to trigger asthma attacks.
Soot also comes to the Arctic from the South. Soot-laden smoke from agricultural or forest fires can stay in the atmosphere for about a week, where it leads to thicker, warmth-catching clouds and what's often referred to as "Arctic haze." | <urn:uuid:9a83f720-222f-40dc-972b-25b372120636> | CC-MAIN-2016-26 | http://www.theprovince.com/mobile/technology/environment/Reduce+Arctic+soot+prevent+more+warming+scientists+urge/4759025/story.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783399117.38/warc/CC-MAIN-20160624154959-00145-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.958655 | 591 | 3.296875 | 3 |
Image: ERNST SCHMID/CHRISTOPH WIRZ
Used as ammunition, it penetrates the thick steel encasing enemy tanks; used as armor, it protects troops against attack. And when it was used in the Gulf War and later during the Allied bombing of Yugoslavia and Kosovo, depleted uranium (DU) was hailed as the new silver bullet that would solve most of the militarys problems.
After the end of Operation Allied Force, however, several Italian soldiers were diagnosed with leukemia. Politicians and the media soon forged a link between the disease and depleted uranium use. They further drew a parallel with Gulf War Syndromeand in no time, depleted uranium became the Agent Orange of the Balkan conflict.
Despite the recent attention, depleted uranium is not all that new. The military has experimented with it since the 1970s. Military interest in the heavy metal is twofold: For one thing, uranium is almost twice as dense as lead, and thus packs a lot of punch as ammunition. Like its slightly denser cousin, tungsten, uranium can penetrate most heavy armor. But whereas tungsten projectiles become rounded at the tip upon impact, uranium shells burn away at the edges. This "self-sharpening" helps them bore into armor.
Also attractive to the military is depleted uranium's abundance. Depleted uranium is a by-product of the process by which uranium 235the most radioactive and most useful form of uraniumis isolated from natural, mined ores (for more information, see the side bar). In 1998 the U.S. Department of Energy had about 500,000 metric tons of depleted uranium in storage.
Depleted uranium armor-piercing incendiary (API) munition comes in two main forms. One is fired from the suitably nicknamed "Tank Buster" A-10 Thunderbolt aircraft; the other shoots from M1 Abrams tanks, which are also enforced with DU armor. Both types of API munitionsa total of 300 tonswere used during the Gulf War. But only the A-10 kind was used during Operation Allied Force in Yugoslavia.
According to a statement by NATO Secretary-General Lord Robertson, some 31,000 rounds of DU ammunition were used throughout Kosovo during the 11 weeks of Operation Allied Force. Each round of A-10 DU ammunition contains a 300-gram DU penetrator slug, which brings the total amount of depleted uranium dropped during the conflict to a little less than 10 metric tons.
Radioactive and Toxic
Image: ERNST SCHMID/CHRISTOPH WIRZ
The question now is whether the metal that lies scattered over a wide area of the Balkans presents a health threat to soldiers and civilians. "There are clearly two issues" with DU, explains David Brenner of Columbia University's School of Public Health, "the radiation and the toxicological issue." Indeed, not only is depleted uranium potentially dangerous because of its radioactivity, it is also a strong toxin. "If there are effects, it would seem to me that the radiation effects would be the smaller of the two," adds Brenner, a specialist in the biological effects of radiation.
In fact, compared to other materials, uranium and depleted uranium are not terribly radioactive (see the side bar). The latter is used to actually shield radiation from fuel rods in nuclear power plants. But that's not to say that they couldn't have some deleterious health effects. As uranium and its daughter products decay, they emit alpha-, beta- and gamma-radiationall of which behave differently within the human body. Gamma-radiation can reach far into the body, but releases its energy gradually. As a result, it has little impact on any one part or organ. Alpha- and beta-radiation, on the other hand, are more hazardous because they have a short range and release all their energy within a small area.
"The so-called RBE, the relative biological effectiveness, for alpha particles is about 20 times higher than that of x-rays or gamma rays," says Tom Hei, also of Columbia University, who studies radiation and cancer. Brenner agrees that alpha-radiation is the biggest concern, but adds that its short range also makes it less harmful in some ways: "The alpha particles have to reach sensitive cells to be of any relevance. The distance they can travel in tissue or water or something like that is in tens of microns." In other words, if a person is exposed to alpha-radiation from the outside of the bodyfrom standing next to a pile of uranium, for examplethe alpha-radiation won't penetrate the skin, if it reaches the skin at all.
So what is important, then, is not so much the amount of radiation involved, but how much enters the body. The relevant unit for the impact of radiation on tissue is the Sievert (Sv), defined as the amount of energy given off in one kilogram of tissue. Another unit to describe the same thing is the Rem (100 Rem is equivalent to 1 Sv).
In a normal setting, a person is exposed to between one and three millisieverts (1Sv = 1,000 mSv) per year. If you were to stand about three feet from 1 kilogram of DU for one yearthe equivalent of about three A-10 shellsyou would be exposed to about one millisievert per year. But the tissues exposed would most likely be skin or fatneither of which are among the sensitive cells Brenner mentions above. Indeed, to do real damage, the radiation would have to reach tissue such as bone marrow.
Theoretically that could happen if a soldier got fragments of uranium embedded in his or her body through injury in combat. During Operation Desert Storm, about 30 soldiers were hurt when their tank was hit by "friendly fire" that contained depleted uranium. As a result of the incident, several soldiers were left with DU shrapnel embedded in their bodies. "Then perhaps the DU is right next to bone marrow, for example, so the alpha particles would have enough range to damage the blood cells," Brenner says. The soldiers' health is being closely monitored, but so far there is no evidence of any ill effects.
Ingested or Inhaled?
Of course, there are other ways that depleted uranium can enter the body. When DU projectiles hit a target, they partly burn up, creating uranium dust particles, or aerosols. Unlike southern Iraq, Kosovo and Yugoslavia are agricultural regions, and some observers have raised the concern that uranium dust particles might enter the food chain through crops.
According to the AC-Laboratorium Spiez, an independent laboratory that tests soil samples for the United Nations and other organizations, only about 17 percent of the DU particles found after a DU explosion are easily soluble, and might thus find their way into foods. Of those, only 2 to 5 percent are actually taken into the blood stream through the digestive system, making it a negligible source of radiation. "That would be the smallest possible source of exposure," says Brenner. "Because, again, the alpha particles would then be within some stuff, within liquid or whatever and it wouldnt have enough range to get out."
Apart from ingesting the aerosols, they can also be inhaleda potentially more harmful path. "When you inhale some of these particlesfor instance, in the case of radon, which is a decay product of uraniumthese particles give off alpha-radiation, which could cause lung cancer," Hei says. The correlation between radon and an increased risk of lung cancer was first discovered in uranium miners, who inhaled large quantities. As many as 75 percent of them got lung cancer. Radon gas also rises naturally from the soil, especially in regions with high granite concentrations such as the New York/New Jersey area.
"It depends on how much [exposure] we are talking about here," Brenner says. "I think you would probably get a bigger exposure just from being in your house than from almost any conceivable DU exposure." Similarly, he does not believe that temporary exposure to the radioactive aerosols will do damage. "If you just inhale radon gas, for example, the alpha particles would be in the air in your lung and would have no range to get to any significant, sensitive cells."
Of importance is where exposure to the aerosols occurs. "In an outdoor setting, like in a war or something, the concentrations would be very low," Brenner says. The worst-case scenario might be for the crew of a tank hit with DU ammunition. According to a study by the AC-Laboratorium Spiez, those soldiers could inhale up to 50 milligrams of uranium aerosol. Still, only about 25 percent of the particles with a diameter less than 10 microns would be deposited in the lungs. And as mentioned above, only a small percentage of them would be easily soluble. The rest would be incorporated into the mucus in the lungs, and coughed or sneezed back out in less than an hour.
To be certain, inhaling or ingesting uranium aerosols delivers some additional radiation to the body, but the real health threat may have nothing to do with radioactivity. "Uranium is a toxin that effects the kidneys," toxicologist Bruce Kelman says. "Once you get the uranium into biological fluids, it mostly goes to the liver and kidneys. It breaks down the tubules in the kidneys that allow you to filter the urine out."
It is difficult to say how little depleted uranium it might take to make a person sick, Kelman says, because it depends on its physical form and whether it was inhaled, ingested or shot into the body. "The U.S. EPA [Environmental Protection Agency] determined that the most appropriate oral measure to use was a study in rabbits indicating that the lowest level at which there was an adverse effect observed was 2.8 mg/kg/day"that is, milligrams per kilogram of body mass per day. To put that into perspective, Kelman observes, "in terms of making the environment dirty, I don't think it makes it any dirtier than any other kind of military munition, where you have lead scattered throughout the environment, where you have toxic components of explosives that are left over."
So thus far, the threat seems negligible, but a certain amount of caution is warranted. "There is a general known lag period between radiation exposure and when a cancer is going to occur, if it's going to occur," Brenner says. "And it's on the order of 20 years or so. So you wouldn't expect to see radiation-related cancers from, say, Kosovo now. That would be against everything we know about how radiation causes cancer." There are two exceptions to that rule: thyroid disorders and leukemia. "Radiation-induced leukemia occurs generally in the first five years."
Most of the controversy over Kosovo has, in fact, focused on leukemia. After several NATO soldiers who served in Kosovo were diagnosed, the World Health Organization investigated whether the number of leukemia cases in Kosovo had risen during the last few years. They came to the conclusion that it had not. But this past November, the United Nations Environmental Program followed up, sending a team of experts to Kosovo to take soil and water samples in 11 locations. "At eight sites the team found either slightly higher amounts of beta-radiation immediately at or around the holes left by DU ammunition, or pieces and remnants of ammunition," Pekka Haavisto, former Finnish environment minister and leader of the UNEPs Balkan Task Force team, said in a statement on January 11.
A later analysis concluded that some of the depleted uranium used during the war contained traces of plutonium and uranium 236neither of which occur naturally, but are created during nuclear fission. This discovery made the origins of the DU a hot political issue and raised additional health concerns because both materials are far more radioactive than regular DU. As it turned out, though, the traces of U236 were so small that they did not change the radioactivity of the depleted uranium; so too, the plutonium content varied from a negligible 0.8 to 12.87 becquerel per kilogram.
Although depleted uranium may not pose an immediate threat, because it is both radioactive and toxic, some action is warranted. Klaus Toepfer, executive director of the UNEP, sums up the recommendations made by the Balkans Task Force in 1999: "Highest priority should be given to finding pieces of depleted uranium and heavily contaminated surfaces. Measures should be taken for the secure storage of any contaminated material recovered. | <urn:uuid:6c401428-fc97-470f-8ad6-55cacfa3965f> | CC-MAIN-2016-26 | http://www.scientificamerican.com/article/the-science-of-the-silver/ | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783397562.76/warc/CC-MAIN-20160624154957-00113-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.966014 | 2,585 | 3.21875 | 3 |
Organic lights and solar cells straight from the printer
Flickering façades, curved monitors, flashing clothing, fluorescent wallpaper, flexible solar cells – and all printable. This is no make-believe vision of the future; it will soon be possible using a new printing process for organic light-emitting diodes.
Time is slowly running out for bulky television sets, boxy neon signs and the square-edged backlit displays we all know from shops and airports. It won’t be long before families gathering together to watch television at home will be calling out: “Unroll the screen, dear, the film’s about to start!” And members of the public may soon encounter screens everywhere they go, as almost any surface can be made into a display. “These may just be ideas at the mo- ment, but they have every chance of becoming reality,” says Dr. Armin Wedel, head of division at the Fraunhofer Institute for Applied Polymer Research IAP in Potsdam-Golm. The first curved screens were on display at this year’s consumer electronics trade show (IFA) in Berlin. The technology behind it all? OLEDs: flexible, organic, light-emitting diodes.
Molecule solutions as ink
But the potential offered by this technology extends beyond screens and displays for consumer electronics, according to Wedel. He believes OLEDs are also ideally suited to all kinds of lighting and to digital signage applications – that is to say, advertising and infor- mation systems such as electronic posters, advertisements, large image projections, road signs and traffic management systems. The scientists worked together with mechanical engineering company MBRAUN to develop a production facility able to create OLEDs as well as organic solar cells on an industrial scale. The innovative part is that it is now possible to print OLEDs and solar cells from solutions containing luminescent organic molecules and absorptive molecules respectively, which makes printing them onto a carrier film very straightforward. Usually, printing them involves vaporizing small molecules in a high vacuum, making it a very expensive process.
Scientists had previously only ever used various printing technologies to design compo- nents on a laboratory scale. They can now produce larger sample series – and this is particularly advantageous for the applications that the IAP has in mind, as large illuminated surfaces and information systems require tailored solutions produced in relatively small numbers. “We’re now able to produce organic components under close-to-real-life manu- facturing conditions with relative ease. Now for the first time it will be possible to translate new ideas into commercial products,” Wedel says.
At the heart of the pilot plant is a robot that controls different printers that basically act like an inkjet printing system. OLEDs are applied to the carrier material one layer at a time using a variety of starting materials. This produces a very homogenous surface that creates a per- fect lighting layer. “We’re able to service upscale niche markets by offering tailored solut- ions, as we can apply the organic electronic system to customers’ specifications, just like in digital printing,” explains Wedel.
Industry experts estimate that printed OLEDs hold out the promise of becoming a billion-dollar market. “The focus in Germany and Europe is on OLED lighting because this is the home market for large companies such as Osram and Philips,” explains Wedel. “The manufacturing facility will help secure competitive advantages in this particular segment of the market. It strengthens the German research community, and also demonstrates the capabilities of German plant engineering,” says Dr. Martin Reinelt, CEO of MBRAUN in Garching.
OLEDs have several advantages over conventional display technologies. Unlike liquid crystal displays they do not require backlighting, which means they consume less energy. As it is the diodes themselves that emit colored light, contrast and color reproduction are better. The electroluminescent displays also offer a large viewing angle of almost 180 degrees. And because they require no backlighting, they can be very thin, making it possible to create entirely new shapes.
There are still several challenges to be met before OLEDs become firmly established on the market. “The main hurdle, as far as I’m concerned, is the high level of investment required to set up manufacturing,” says Wedel. This is why, at least where lighting is concerned, he expects OLEDs to complement rather than replace conventional lighting devices. His view of where OLED production technology could head is less modest: “My vision is that the day will come when all we need do is switch ink cartridges in our printers in order to print out our own lighting devices.” | <urn:uuid:43d2f28b-f1d4-4505-8c01-1e4b8041a40c> | CC-MAIN-2016-26 | http://www.fraunhofer.de/en/press/research-news/2013/november/organic-lights-and-solar-cells-straight-from-the-printer.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783402479.21/warc/CC-MAIN-20160624155002-00031-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.941437 | 984 | 2.703125 | 3 |
Complex Chemistry Naming Complexes
A selection of articles related to complex chemistry naming complexes.
Original articles from our library related to the Complex Chemistry Naming Complexes. See Table of Contents for further available material (downloadable resources) on Complex Chemistry Naming Complexes.
- Bringing it Down to Earth: A Fractal Approach
- 'Clouds are not spheres, mountains are not cones, coastlines are not circles, and bark is not smooth, nor does lightning travel in a straight line.' B. Mandelbrot W e want to think about the future - it's our nature. Unlike other creatures, humans possess an...
Mystic Sciences >> Astrology
- Everyday Earth
- When you think of "Earth" what comes to mind? Perhaps you feel the stable element of solidity and grounding. Or maybe you see Earth as the third planet from the Sun. Or for you, is Earth the rich brown soil in your own backyard? Earth is all these...
The Elements >> Earth
- About Alchemy
- "The science of alchemy I like very well, and indeed, 'tis the philosophy of the ancients. I like it not only for the profits it brings in melting metals, in decocting, preparing, extracting and distilling herbs, roots; I like it also for the sake of the...
Mystic Sciences >> Alchemy
- Can You Bhoga All Night Long? An Introduction to Tantra, East and West
- When you hear the word Tantra, what images come to mind? Turbans and Sitar music? Mind-blowing sex? Most people in the Western world have heard the word Tantra, but few know anything in detail about what it means. The situation in India isn't much different....
Body Mysteries >> Yoga
- What is hypnotic trance? Does it provide unusual physical or mental capacities?
- 2.1 'Trance;' descriptive or misleading? Most of the classical notions of hypnosis have long held that hypnosis was special in some way from other types of interpersonal communication and that an induction (preparatory process considered by some to be...
Parapsychology >> Hypnosis
Complex Chemistry Naming Complexes is described in multiple online sources, as addition to our editors' articles, see section below for printable documents, Complex Chemistry Naming Complexes books and related discussion.
Suggested News Resources
- A sustainable restoration?
- A wetland complex comprises major wetlands, buffer wetlands, and inter-connecting channels, and Chennai is home to 474 such complexes. Jayshree Vencatesan, Managing Trustee, Care Earth Trust, says the project has many benefits and is a welcome ...
- City asked for $18.75 million for new youth sports complex
- A recently released economic impact study showed that over 20 years the complex could generate $450 million in spending at Lexington hotels, restaurants and other businesses. Elizabethtown and Bowling Green have built similar complexes.
- More discount apartments coming to San Diego
- But more complexes are on the way. That includes a North Park development that will offer an accepting environment for senior LGBT residents. Further south, Community Housing Works is also gathering names for a complex open to all ages in National City ...
- Overcrowding in New York City Housing Authority fueled by lack of jobs and
- The New York City Housing Authority (NYCHA) administers more than 325 separate complexes, totaling about 175,000 apartments. Rents are no more than 30 percent of household monthly income. The population in public housing, ...
- Crashing down by ocean; inscription from 1776; investigating missing soldiers
- Waves crash below cliffside apartments that have been evacuated and are slated to be eventually demolished in Pacifica, Calif.
Great care has been taken to prepare the information on this page. Elements of the content come from factual and lexical knowledge databases, realmagick.com library and third-party sources. We appreciate your suggestions and comments on further improvements of the site. | <urn:uuid:b5c8d344-04b5-4dee-9c82-30c3b6147905> | CC-MAIN-2016-26 | http://www.realmagick.com/complex-chemistry-naming-complexes/ | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783396027.60/warc/CC-MAIN-20160624154956-00032-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.918549 | 828 | 2.609375 | 3 |
Every week it seems like a new study comes out with a bold new pronouncement. A cup of coffee can extend your life. Or it can hasten your death. A new treatment is trumpeted or certain foods or lifestyle are demonized. Yet many of these reports distort the facts, exaggerate findings or simply aren’t true.
The journal Heart published an editorial last week about how extreme runners face a higher cardiac risk. Many subsequent reports jumped on the idea that running was bad for you but failed to properly qualify the findings.
Earlier this fall, dozens of headlines touted the benefits of multivitamins after a study in the Journal of the American Medical Association found multivitamins cut cancer rates in older men. But the actual reduction in cancer was so small that one cancer expert said it doesn’t make sense to recommend people take multivitamins.
The reliability of health news is a serious matter. The inclination of medical journals and media outlets to only publish studies that have dramatic or controversial results fuels the trend toward sensationalism in health reporting.
“You can give very misleading ideas about what’s important in health and what isn’t,” said John Briffa, a British doctor who focuses on issues related to nutrition.
Changing how researchers, public-relations professionals, medical journals and health reporters do business is an enormous challenge. Like any other media publications, many medical journals need readers and subscribers to stay competitive and financially viable. That means they’re always on the lookout for research that can attract eyeballs. At the same time, the public-relations departments of universities, hospitals and other research institutions are keenly aware of the importance of getting their organization’s name in the media. The publicity can help ensure an institution maintains research funding and a good reputation. And then there are journalists, who have to evaluate countless press releases and journal abstracts to decide which one is most “newsworthy” and likely to draw readers.
“The [studies] that seem most attractive to most investors and peer reviewers and journals are the ones that find the most spectacular results,” said John Ioannidis, a professor of medicine at Stanford University.
“There’s a desire to possibly make one’s research look more meaningful than it is in reality,” said Briffa. “Evidence can be misrepresented, overhyped and be quite misleading.”
The problem is that while a medical study may be poorly designed, have a small sample size or is otherwise flawed, it can be presented in a press release as being a major breakthrough or discovery.
The American Journal of Cardiology weighed in on the issue last month, urging researchers to decrease the use of overly positive or dramatic language. Too often, the editorial says, researchers use declarative statements or other strong language that simply doesn’t match the reality of the study findings. And while most medical journals require researchers to disclose funding sources, particularly those that can pose a conflict of interest, very rarely are they noted on press releases.
When poor-quality study results appear in the media, it not only misinforms the public, but can lead to unnecessary worry. Take, for instance, a press release on a study from the University of Western Ontario this year that said egg yolks are as bad for health as smoking. The same group published a similar paper a year earlier that equated eating egg yolks with KFC’s gluttonous Double Down sandwich. The story appeared in media outlets around the world, but faced harsh criticism from nutrition experts who pointed out the study was flawed and the conclusions aren’t valid.
Journalists have a responsibility to look past the press release and evaluate the true merits of the study. However, Andreas Laupacis, executive director of the Li Ka Shing Knowledge Institute of St. Michael’s Hospital in Toronto, said the real issue may be with the way scientists and research organizations present their work.
“I think a lot of reporters do try to have a balanced view,” he said. “When scientists are talking to the press, they’re obviously wanting to give the public information about something they think is important … but they’re also selling the information a bit.”
As Ioannidis, who is well-known for a 2005 article he wrote titled “Why Most Published Research Findings Are False,” says, “We have to take every result with a grain of salt.”Report Typo/Error | <urn:uuid:74574aeb-9920-4738-b3ff-1a9fd1bbf89c> | CC-MAIN-2016-26 | http://www.theglobeandmail.com/life/health-and-fitness/health/how-reliable-is-your-health-news/article5861333/ | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783394414.43/warc/CC-MAIN-20160624154954-00110-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.939146 | 944 | 2.53125 | 3 |
(PRINCETON, N.J.) -- Intrauterine devices, or IUDs, have been shown to be the best and most reliable emergency contraceptive for women, according to a new study published in the journal Human Reproduction.
An IUD is a T-shaped plastic or copper device that is placed in a woman's uterus to prevent pregnancy. They can be left in the womb between five and 10 years, depending on the brand, but they can also be used as a means of emergency contraceptive. They should be inserted within five days of unprotected sex to properly protect, experts said.
The research showed that IUDs had a failure rate of less than one per 1,000, which was more effective than the morning-after pill, which had a failure rate of 1 to 2 percent. The morning-after pill, or Plan B One-Step, is a pill that should be taken within 72 hours of unprotected sex to avoid pregnancy.
"Emergency insertion of a copper IUD is extremely effective," said James Trussell, professor of public and international affairs at Princeton University and lead author of the study. "We would hope [the findings] would encourage clinicians to talk with women about emergency insertion of a copper IUD during regular visits for later use, should the need arise."
The study analyzed data from 42 studies conducted in six different countries (China, Egypt, Italy, The Netherlands, U.S.A. and the U.K.) between 1979 and 2011. They found that women became pregnant at a rate of 0.09 percent if they used an IUD, as opposed to the 1 to 2 percent pregnancy rate on the morning-after pill.
The research also found that using an IUD for emergency contraception worked just as effectively in women with higher body mass index, while the morning-after pill became less effective at preventing pregnancy in women with higher BMI.
"IUDs are certainly a highly effective form of emergency contraception," said Dr. Ranit Mishori, an assistant professor in the department of family medicine at Georgetown University. "The study appears to confirm it, [but] I think not many women are aware that it is an effective option."
While the device is indeed better at preventing pregnancy, experts say that it is not necessarily the best option for everyone.
"Here are the problems: the IUD has to be inserted and most of the time, ordered," said Dr. Jacques Moritz, director of gynecology at St. Luke's-Roosevelt Hospital in New York. "They are way overpriced in this country. You can't just walk in my office and get an $800 IUD. We have to get it authorized and ordered."
On the other hand, any woman over the age of 17 can buy Plan B One-Step at a pharmacy without a prescription. Females under the age of 17 must have a prescription to obtain the product.
Copyright 2012 ABC News Radio | <urn:uuid:b1b37e83-0b1d-42e0-a3e7-7d2cd1fb6d4b> | CC-MAIN-2016-26 | http://abcnewsradioonline.com/health-news/tag/morning-after-pill | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783397213.30/warc/CC-MAIN-20160624154957-00079-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.965463 | 603 | 2.78125 | 3 |
In Dying Color
X-ray color images of supernova remnants (the debris exploded out from dying stars) are providing astronomers with fascinating new insights into these titanic stellar blasts. The images above are two of the best examples. On the left is the Chandra image of the Cas A supernova remnant, produced by the death of a star initially many times more massive than our sun after exhaustion of its nuclear fuel. A point source at the center of the remnant is possibly the collapsed core of the star that exploded. On the right is an image of Tycho's supernova remnant (which was produced by a stellar explosion observed by the Danish astronomer Tycho Brahe in 1572). The star which produced Tycho's Remnant is thought to have been produced by an explosion of a collapsed core of a star initially like the sun, after a companion transferred more mass than the collapsed object could withstand. Presumably most of the differences in morphology of the 2 remnants are due to the different causes of the stellar explosions. In each image, low energy X-rays produce red emission, medium produce green emission, and high energy X-rays produce blue emission. In the Chandra image of Tycho's Remnant, a hot blue shock wave of 20 million degree gas can be seen around the rim of the remnant.
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Last modified September 9, 2002 | <urn:uuid:cdef43a6-5a07-4c29-81f9-ca2cd73efbdb> | CC-MAIN-2016-26 | http://heasarc.gsfc.nasa.gov/docs/objects/heapow/archive/nebulae/chandra_color_snr.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783398628.62/warc/CC-MAIN-20160624154958-00059-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.906462 | 341 | 3.625 | 4 |
-by Candice Shaw, Grade 6 Math/Science
In the Grade 6 curricula, there are many opportunities for meaningful integration between subjects. The Sky Science unit and Large Number topics fit harmoniously together.
With a focus on problem solving, students first went about solving a variety of astronomy themed problems, such as “How many times further is Saturn’s distance from the Sun than Earth’s distance from the Sun?” These problems had students working with numbers in the millions and billions, as well as estimating, rounding, using appropriate units and converting distances.
This problem solving was culminated with a major group problem:
“How can we build a proportional model showing the distance of the planets from the Sun? How far are each of the planets from the Sun, in Astronomical Units?”
Students had seen many models throughout the Sky Science unit, and they were able to intelligently discuss the above model of the planets. They concluded that there were many flaws in the model, especially when it came to scale. Proportional models were introduced and discussed, using maps as examples. Non-examples were also provided, and proportionality was related to previously discussed geometric transformations (dilation).
Students were given few restrictions to compose their scales, but it was decided upon that it must be of manageable size. Finished products ranged from 75 cm to 4.5 m in length.
Many groups chose to round some of the numbers given, after a lengthy debate/problem on significant differences and rounding numbers. In almost all cases, the rounded numbers provided accurate answers (when compared to calculations with the exact provided numbers).
Using Earth as a benchmark was helpful for some groups. They realized that Earth is 1 AU from the Sun (as that is the definition of an AU). The groups that used AU in their models seemed to have an easier time with organizing their planets along the scale. Many groups did not take this approach and worked with millions of km instead and had to provide many conversions to create their scale.
Many groups did not have formal knowledge about making a scale, and often used logical approaches, based on their chosen scales. Measuring tapes and other manipulatives were helpful for struggling groups.
Almost all groups came up with accurate answers and most provided calculations on the final copy of the problem, but the real interesting information was in the group conversations while devising a scale, model and converting units. Also, every group needed to discuss ideas in various ways, before all members understood the process. Conversion and making a proportional scale is not a simple task to get your head around.
Even though this turned out to be a difficult problem for many students, they found value in having to figure it out themselves, rather than being given a predetermined method for finding a scale. Students were excited when they grasped the ideas and were enthused to speak with others about their findings. Models were compared to one another to ensure that proportional relationships were similar, even when based on different scales. Students were also enlightened about the vastness of the solar system and their curiosity about astronomy topics prompted inventive math work. | <urn:uuid:0b92774d-9992-4f6b-aed3-7a0778ed780c> | CC-MAIN-2016-26 | http://calgaryscienceschool.blogspot.ca/2012/04/big-numbers-and-sky-science-grade-6.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783392527.68/warc/CC-MAIN-20160624154952-00128-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.98115 | 633 | 4 | 4 |
Robust export performance turned the ROK's overall balance of payments deficit into a $1.7 billion surplus in 1986, which grew to $12.1 billion in 1988. Since then, the balance of payments surplus has declined; in 1990, the balance of payments had a deficit of $274 million because of declining exports, rising imports, and a current account deficit. Over the long term, growth in exports will depend on industry's efforts to regain competitiveness lost through wage increases, labor unrest, and exchange rate changes. The deficit grew to over 4% of GDP in 1996, before subsiding in 1997 due to a shrinking currency base.
At the end of 1998, South Korea had $20.2 billion in net outstanding loans, but by the end of 1999, it had become a net creditor. By the end of April 2001, $33.3 billion in outstanding loans were owed the country.
The US Central Intelligence Agency (CIA) reports that in 2002 the purchasing power parity of South Korea's exports was $159.2 billion while imports totaled $146.6 billion resulting in a trade surplus of $12.6 billion.
The International Monetary Fund (IMF) reports that in 2001 South Korea had exports of goods totaling $151.4 billion and imports totaling $138 billion. The services credit totaled $29.6 billion and debit $33.1 billion. The following table summarizes South Korea's balance of payments as reported by the IMF for 2001 in millions of US dollars.
|Balance on goods||13,392|
|Balance on services||-3,527|
|Balance on income||-886|
|Direct investment abroad||-2,600|
|Direct investment in South Korea||3,198|
|Portfolio investment assets||-5,499|
|Portfolio investment liabilities||11,856|
|Other investment assets||7,458|
|Other investment liabilities||-11,764|
|Net Errors and Omissions||-2,698|
|Reserves and Related Items||-13,416| | <urn:uuid:22d09800-27a9-4344-939f-b97cf4263336> | CC-MAIN-2016-26 | http://www.nationsencyclopedia.com/Asia-and-Oceania/Korea-Republic-of-ROK-BALANCE-OF-PAYMENTS.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783395679.18/warc/CC-MAIN-20160624154955-00088-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.923445 | 429 | 2.59375 | 3 |
Breast cancer is the top cancer in women both in the developed and developing countries.
According to the World Health Organization, mortality on the said disease continuously increases as most of the cases are diagnosed in late stages.
This proves that early detection remains as the most effective way of surviving breast cancer. Women aged 40 and above are advised to undergo breast cancer screening methods.
However, detection of the disease is only half of the battle. At Asian Hospital and Medical Center (AHMC), patients are guided during the different phases of fighting the disease: detection, treatment and recovery.
Breast cancer screening methods vary depending on the patient’s needs—risk assessment and clinical breast examination, mammography, ultrasound, magnetic resonance imaging (MRI) and biopsy.
As part of the screening process, patients are taught breast self-examination, which promotes breast cancer awareness among women and can help identify signs and symptoms indicating the presence of the disease.
After achieving the results, a multidisciplinary team specialized in cancer will discuss appropriate treatment method for the patient using AHMC’s state-of-the-art medical facilities.
Patients are not only treated with their health problems but are also emotionally and spiritually encouraged to fight their disease. AHMC offers holistic healing on all types of cancer, with the belief that cancer is not the end and there can be quality life after the disease.
Prevention is still better than cure. AHMC advises women to lead a healthy lifestyle—choose a healthy diet, exercise regularly, avoid smoking and keep alcohol intake in moderation.
The Asian Hospital and Medical Center is the only premier hospital in the country that has a one-stop breast health facility. For more information about its breast cancer screening and treatment services, visit www.asianhospital.com. | <urn:uuid:59845c5a-5635-4a3d-bebd-9463aef90c6c> | CC-MAIN-2016-26 | http://business.inquirer.net/140949/asean-hospital-womans-partner-vs-breast-cancer | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783392527.68/warc/CC-MAIN-20160624154952-00167-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.952606 | 365 | 2.765625 | 3 |
Plan for blooms from April to October - their arrival and departure dates here in Western Maryland.
Next, garden in layers from high to low to create a hummingbird smorgasbord and visual feast.
Must the flowers be red and tubular?
No. Hummingbirds do favor bright, tubular flowers suited to their long, skinny bills and tongues. But they are attracted to any flowers heavy with nectar.
So mix it up.
Some of hummingbirds' favorite perennials are bee balm, coral bells, foxglove and bleeding heart. Preferred annuals include fuchsia, petunia, lantana, morning glory, larkspur and nasturtium. Both annual and perennial salvia and phlox are good choices as are canna lily and gladiolus grown from bulbs.
Trumpet creeper and coral honeysuckle vines are irresistible to hummingbirds, as are the flowering shrubs weigela, butterfly bush and rose of Sharon.
Think hummingbirds ignore trees? Think again.
The nectar-rich flowers of the mimosa and red buckeye trees (Aesculus pavia) are impossible to resist.
Several native plants entice hummingbirds. Native columbine (Aquilegia canadensis) blooms in concert with their arrival in mid-April. Summer favorites include the native perennials beard tongue (Penstemon digitalis), cardinal flower (Lobelia cardinalis) and orange jewelweed (Impatiens capensis).
Add a hummingbird feeder to supplement your garden plants to bring hummingbirds in for an up-close-and-personal view.
Good feeders are sturdy and easy to clean with multiple feeding ports. Hang your feeder several feet off the ground, where you can see and enjoy it. And remember to clean and refill it every few days.
You can make your own hummingbird nectar by boiling one cup of water, stirring in a quarter cup of white sugar and allowing it to cool. Any 4-to-1 ratio is fine.
Don't add red dye. It's not necessary and can be harmful.
Hummingbirds prefer a shower to a bath, so investing in a mister or dripper for your birdbath is a smart move. Hummingbirds love to dance in the fine spray to clean themselves and cool off on hot days.
Hummingbirds are charmers. One regularly "rings" the giant bell-like flowers of my yucca, tucking inside for sip after sip, making the blooms sway. Another likes to slip under my patio umbrella for nose-to-nose chats.
The males have jousting matches with their beaks at my feeder.
And one very special day, I rescued a tired hummingbird and revived it with sugar water as I cradled it in my hand. Wondrous.
Gardening really is for the birds. And when you garden for hummingbirds, the rewards are beauty on the wing.
To receive a free copy of a list of plants that attract hummingbirds, just e-mail or call.
Annette Ipsan is the Extension educator for horticulture and the Master Gardener program in Washington County for the University of Maryland Cooperative Extension. She can be reached weekdays by telephone at 301-791-1604, or by e-mail at [email protected] | <urn:uuid:beeb264a-5c72-4038-bc72-78b08845b3f0> | CC-MAIN-2016-26 | http://articles.herald-mail.com/2007-04-03/news/25065459_1_ruby-throated-hummingbirds-trumpet-creeper | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783396872.10/warc/CC-MAIN-20160624154956-00079-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.908072 | 710 | 2.546875 | 3 |
[[In his assessment of the significance of Ardipithecus ramidus, bipedality expert C. Owen Lovejoy wrote, “We can no longer rely on homologies with African apes for accounts of our origins and must turn instead to general evolutionary theory.”2 Thus, setting aside evolution-inspired ideology, there is no scientific reason—or observed evidence—to believe that Ardi was an ancestor of mankind. In fact, there is every reason to believe it is solely an extinct primate, as uniquely created as any monkey still alive today.]]
This is a gross fallacy. Lovejoy says in this case to go from specific to general evolutionary theory. The author interprets this to mean to abandon evolutionary theory and completely discount it as unscientific.
[[Based on the Bible’s description of origins, one would predict that all “hominids” should actually be either wholly man or wholly ape. Based on the scientific evidence, Ardipithecus was clearly an ape, and as such fits the Genesis account that each creature group was created as its own kind.]]
A combination of two gross fallacies.
1) Appeal to authority. It’s impossible to obtain legitimate scientific results by using the Bible to interpret scientific theories. The Bible is not a legitimate source of science, any more than a science textbook is a legitimate source of religion.
2) Circular reasoning. Based on the scientific evidence, all hominids are apes. To say that humans are not apes because only apes are apes is fallacious.
If you want to use the authority of the Bible to say that evolution is not a legitimate theory, go right ahead. But attempting to use science to refute it is not going to work, especially if those attempting it don’t understand basic science, as is clearly being demonstrated by this website.
Good post ... Thank you ... Meanwhile, let me quote — on topic — from Steve Jones’ book “Darwin’s Ghost,” published ten years ago. From page 322 we have ...
“About fifteen million years after the emergence of the first primate, the predecessors of apes appear. A molecular clock based on inserted viruses suggests that the lines to chimp, to gorilla and to humans split some five million years ago. A dozen or so hominines — as the branch upon which we belong is called — have lived since then (although how many are real entities is hard to assess). Over that period, there appeared Ardipithecus (four and a half million years old and of intermediate form); several kinds of Australopithecus (an African primate from around a million years later which was, roughly speaking, a human below the neck but an ape above): and Homo habilis (an animal defined as having crossed the central rubicon of brain size needed to qualify for our own family).” .
And etc. Then more ...
“The first members of our own species, Homo sapiens, arose about a hundred and fifty thousand years ago. By the time the miseries of the ice ages were over we were, more or less, ourselves, with smaller brains in a thin skull on a slim and elegant body.”
For what it’s worth ... Go with knowledge. | <urn:uuid:1e69e5e9-8b0b-4c23-b76c-329ec6de4198> | CC-MAIN-2016-26 | http://www.freerepublic.com/focus/news/2377528/replies?c=20 | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783398075.47/warc/CC-MAIN-20160624154958-00119-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.94963 | 677 | 2.59375 | 3 |
|John Broskie's Guide to Tube Circuit Analysis & Design|
27 June 2006
DACs & Tubes
Digital-to-analog converters (DACs) and vacuum tubes: it’s odd that I haven’t covered this topic before. This topic is so big that several blog entries will be needed no doubt. When I mentioned that I was going to cover this topic, I was asked, "What’s a DAC?" My answer tickled me so much that we will take a small detour on the way to DACs and tubes.
Today, we are all dualists, happily splitting existence into two parts; holding the view that the world consists of (or is only explicable as) two opposing entities. For example, mind vs. matter, soul vs. body, freedom vs. determinism, subjective vs. objective, yin vs. yang, good vs. evil, the faithful vs. infidels, blue vs. red states, or some other pair of different and irreducible principles. So ingrained is the dualist view that few are conscious of holding it, just as fish are not conscious of the ocean. Don't believe me, just ask around. Although few will admit to being a dualist, most will tell you that they believe in a divided universe, that the laws of physics do not apply to the mind or soul, for example. (Here’s an interesting example, even those who believe that Pentiums can and do think and, and yes, that they are just as capable of consciousness as any of us—strong artificial intelligence proponents, in other words—even these extreme materialists believe in a software-hardware dualism.)
The big problem all types of dualism faces is that if there are two primary, fundamentally opposed entities, like spirit and flesh, how do they interact? How does a mass-less entity like your soul push around a mass-filled entity like your body? Well, a few hundred years ago, an answer was offered by the French philosopher/scientist/mathematician, René Descartes.
As the father of modern philosophy, science and mathematics, and a certain semifinalist in the contest of the greatest minds that ever lived, Descartes was no simpleton. (If you think otherwise, Isaac Newton, for one, would vociferously argue the contrary. Most certainly, Newton could not have been Newton without Descartes broad shoulders to stand on. Moreover, we can add Einstein to this list. In fact, many see Einstein as having applied Cartesian corrections to Newtonian physics.) While Descartes did not invent dualism—Zoroaster or Plato probably should get the credit—he did buttress and promote it more successfully than just about anyone before or since (with a knowing nod to Kant).
Well, was he right? Well, are there mental states independent of matter? Is there physical material independent of thought? Perhaps the better questions is, "Who knows?" One interesting finding is that when radioactively-tagged LSD is administered to a subject, most of the LSD is found traveling to the liver, an organ not much celebrated in higher conscious circles. The little LSD, and I do mean little, that finds its way into the brain most of this fraction lodges itself in the pineal gland. Interesting.
What does this have to do with DACs and tubes? If you listen to music through an iPod or a computer’s sound card or CD or DVD player or records that were mastered from digital recorders, then you live with a sharp dualism: sound reproduction based on digital and analog principles. The digital world is filled with zeros and ones; the analog world, with linear electronics and woofers and tweeters. These two worlds have almost nothing in common, yet we do listen to MP3 files and CDs. The DAC is like Descartes’ pineal gland, in that it mediates between digital and analog. However, unlike the pineal gland, it cannot act as a go-between in both directions, as it only translates jerky zeros and ones into flowing and ebbing analog signal. An analog-to-digital (ADC) converter renders sinewaves into digital data, data that could reside on magnetic tape or optical disks or even in a printed book.
In other words, the DAC is critical. Should it neglect or mangle the music encrypted in those ones and zeros, no amount of single-plate 2A3s or beeswax-filled coupling capacitors and hand-carved horns and $3,000 power cords is going to restore the missing music. Therefore, using the best DAC you can afford is money well spent. Fortunately, even the best DACs are not all that expensive; compared to $3,000 power cords, they are downright cheap; for example the highly esteemed AD1955 costs less than $8 each; the WM8740, less than $6.
No mater which DAC you chose, be sure to read carefully the data sheet for clues and tips on how to get the most from the device. For example, the PCM63 contains a 2mA constant-current source to load its current output. This CCS can be disconnected from the output and replaced by another CCS of our own design or maybe left out altogether, as the 2mA offset current might be supplied by our tube-based I-to-V converter stage.
Two types of DACs
By the way, Wolfson created a very clever voltage-output DAC in the WM8740. Below is a quote from EDN:
Clever, very clever. Did you spot the neologism (hmmm...is it a "new word" or just plain "not a word"?): “nonidealities.” Since “ideality” can mean existing as an idea, not a reality, does a “nonideality” exists as a reality, not an idea? Or does it just mean icky stuff?
Multi-bit & delta sigma
Which is better, voltage-output or current-output? (Those who expect to me to write “Better for what?” will not be disappointed.) Better for what? Better sounding? Better to hook up to vacuum tube circuitry?
In theory, I would have to declare the current-output DACs as the optimal sonic choices, as they would hold one fewer solid-state circuit, the current-to-voltage converter, as I have never seen a DIP DAC with tube sockets imbedded on top.
On the other hand, if we focus on practical reality, then the voltage-output DAC is a much better choice for tube-based output circuits. Why? Because tubes are relatively high-impedance devices and current-output DACs, like inductors, prefer low impedances, whereas voltage-output DACs, like capacitors, prefer high-impedances. For example, it would be a breeze to wind a low-pass inductor for a 0.1-ohm woofer, but painful to do the same for a 1Meg woofer; just as it would be cheap to buy a high-pass capacitor for a 1Meg tweeter, but hugely expensive to do the same for a 0.1-ohm tweeter. Do the math.
In addition, current-output DACs put out a varying current that must be converted in voltage, if a triode’s grid is going to receive the DAC’s output signal. Although all the DAC data sheets advise against it, many tube practitioners (I among them) have loaded the DAC’s current output with a resistor to perform the current-to-voltage conversion. Usually, the I-V resistor is small in value, say 100 ohms, but note how far from zero ohms we have traveled. See PCM63 I/V resistor value tests to read more on I-V resistor values and their effect on the DAC's output.
(I did my own tests with the TDA1541 and PCM63 DACs and I-V resistor values. I found that 60 ohms sounded better than 100 ohms and my guess is that 10 ohms would sound better still.) The DAC’s 1 to 2mA output current against 100 ohms equals 0.1 to 0.2V of output, which isn’t too small, but it is 20dB to 14dB lower than 1V of input signal. Against 10 ohms, only 0.01V would develop, which would be 40dB lower.
The other workaround is to use a step-up transformer to couple the DAC’s output to a higher impedance load, but this seldom works as well as we would hope, as 1mA of output current is so small; 10-50mA would be much more useful. Furthermore, wide-bandwidth, low-noise, well-shielded small-signal transformers are both rare and expensive. Still, there is a lot to be said for breaking the ground connections; and the low-pass high-frequency attenuation that the transformer provides can only help.
Furthermore, many current-output DACs were designed with the strict expectation of a near-zero input impedance from the I-V converter stage. Unfortunately, such a low input impedance is all but impossible with common vacuum tubes like the 12AX7 or 6DJ8, unless you include many tubes and much feedback. (The DAC’s output contains a good bit of high-frequency energy, which is bad news for most feedback amplifiers, so high feedback ratios and multi-stage amplifiers are to be avoided.)
In contrast, a 12AX7 would be quite happy to accept a 1-volt input signal from a voltage-output DAC. (One volt of signal is about 200 times greater than the output of a moving magnet phono cartridge, which a 12AX7 has no little problem amplifying.) In fact, we now run into a new problem: too much gain. Some voltage-output DACs put out over 2V of peak output, which against the 12AX7’s gain of 50 or more, provides far too much gain, as most power amplifiers require only 1V to be driven to full output. Some have used step-down transformers or voltage dividers to reduce the DAC’s voltage output to levels better suited for the tube amplifier.
So, the current-output DACs provide too little gain (when working into a I-V converter resistor) and the voltage-output DACs provide too much gain. Or do they? Why does the tube output stage have to provide any gain, if the voltage-output DAC’s output is 2V? The quick answers are that cathode followers are evil and that some high-frequency filtering must be implemented on the output signal. Well, I buy the second argument. However, if an intelligently-designed cathode follower is used, there is no reason why the sound must suffer. Below is a simple and good sounding cathode follower (the seemingly redundant cathode resistor is critical in buffering the cathode from excessive capacitance and for linearizing the triode's transfer curve, at the cost of a slightly higher output impedance).
This simple cathode follower shown above is single-ended in operation and posseses a very good PSRR figure, as long as both negative and positive power supply rails share the same noise signature, equal in amplitude but opposite in phase.
The White cathode follower below is a push-pull circuit that also exhibits a low noise output and an output impedance half that of the simple cathode follower; it can also put out twice the current swing. The simple RC high-frequency filter at each input is there to shunt away the high-frequency nastiness. A more complex circuit could be used, but I would recommend using a passive filter, maybe even an LC filter. Why? The higher the frequency, the less effective an active filter becomes. (Conversely, the lower the frequency, the better suited the active filter becomes.)
If the following stage holds its own input coupling capacitor, then both cathode-follower circuits can be direct-coupled at the output.
Now for something really important
I think that I will wait for an ivory version that sells for $2,500 instead. Remember, the first rule of high-end audio: its only as good as it costs.
Aikido PCBs for as little as $24
WHAT IS AN AIKIDO AMPLIFIER?
The Aikido tube topology, created by John Broskie, delivers the sonic goods. Since the Aikido circuit came out in the Tube CAD Journal, people have been building it and marveling at its sound. A prediction: just as the 1980s were the cascode decade and the 1990s, the SRPP decade, this decade will be known as the Aikido decade. Why?
This amplifier circuit offers voltage gain, low distortion, low output impedance, and a high PSRR figure—all without a global feedback loop.
Better than SRPP
Always Biases Up Correctly
No Popping Sounds at Startup,
A Sound that’s Hard to Improve Upon
AIKIDO AMPLIFIER PCB
What makes them superior? First of all, they look fabulous and feel solid in the hand: extra thick (inserting and pulling tubes from their sockets won’t bend or break this board), double-sided, with 2oz copper traces, clean silkscreen and solder mask. (The board holds two sets of differently spaced solder pads for each resistor, so that radial and axial resistors can be easily used. Each capacitor finds several solder pads, so wildly differing sized coupling capacitors can neatly be placed on the board.) Each board holds two Aikido linestage amplifiers; so, one board for stereo unbalanced or one board for one channel of balanced amplification.
The boards hold two coupling capacitors, each finding its own 1M resistor to ground. The idea here is that you can select (via a rotary switch) between C1 or C2 or both capacitors in parallel. Why? One coupling capacitor can be Teflon and the other oil, or polypropylene or wax and paper…. As they used to sing in a candy bar commercial: “Sometimes you feel like a nut; sometimes you don't.” each type of capacitor has its virtues and failings. So, use one type of coupling capacitors for old Frank Sinatra recordings and the other for string quartets. Or the same flavor capacitor can fill both spots: one capacitor would set a low-frequency cutoff of 80Hz for background or late night listening; the other capacitor, 5Hz for full range listening. Or if you have found the perfect type of coupling capacitor, the two capacitors could be hardwired together on the PCB, one acting as a bypass capacitor for the other.
The board assumes that a DC 12V power supply will be used for the heaters, so that 6.3V heater tubes (like the 6SL7 and 6SN7) or 12.6V tubes (like the 12SL7 or 12SN7) can be used, for example on an octal board. Both types can be used exclusively, or simultaneously; for example 12SX7 for the input tube and a 6BX7 for the output tube. (A 6V heater power supply can be used, as long as all the tubes used have 6.3V heaters; and an AC heater power supply can be used, if the heater shunting capacitors are left off the board.)
The boards are four inches by ten inches, with eight mounting holes. Boards are made in the USA and come with instructions that include schematic and recommended part values.
A real E-mail from a new Aikido PCB owner:
Visit our Yahoo Store for more details:
|www.tubecad.com Copyright © 1999-2006 GlassWare All Rights Reserved| | <urn:uuid:82237b87-7b37-432e-a22e-38a4e597ad16> | CC-MAIN-2016-26 | http://www.tubecad.com/2006/06/blog0070.htm | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783397562.76/warc/CC-MAIN-20160624154957-00150-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.936853 | 3,336 | 2.90625 | 3 |
Mennonites vs Hutterites
Mennonites and Hutterites are communities based on Anabaptist. Hutterites are community which acts as Anabaptist’s branch with roots that trace to the 16th Century’s Radical Reformation. After Jakob Hutter, the founder of Hutterites, passed away in the year 1536 the Hutterites have been wandering in a number of countries for a large number of years. Hutterites were almost out of existence in the time period near the 18 and 19 century. However, Hutterites searched and settled down in North America where they made a new home and increased their population through a period of 125 years from a low number of 400 to 42,000. Hutterites have their origins from Tyrol province in Austria and they can be traced back up till 16th Century.
Mennonites are also a community which has been derived from the basics of Anabaptist. The community has got its name after Frisian Menno Simons. Teachings of this community are based on their belief in ministry and mission of the Jesus Christ. Even after being hindered by a number of states, the Mennonites have kept stuck to their teachings. Mennonites, historically, have been known for their nonviolence making them being called with the name of ‘Peace Churches’. According to a report of 2006, 1.5 Million Mennonites are living in the world. Mennonites hold their major amount of population in Congo, United States and Canada. In addition to these three countries, Mennonites are found in a large numbers in 51 countries of at least 6 continents. Mennonites are widely scattered all across the globe with their population in China, Germany, Paraguay, Mexico, Brazil, Argentina, Bolivia, and Belize where the Mennonites have formed large colonies. Mennonites have formed a Disaster Service which has its basis in North America which offers its services in areas which have been hit by various types of disasters like floods, earthquakes, hurricanes, etc. Mennonites also work with a number of other programs in order to provide relief services in different portions of the world. Mennonites have been nonviolent for a long period of time and have been seen following this tradition and have got themselves indulged in issues of justice and peace. The Mennonites have also founded Christian Peacemaker Teams.
Mennonites have got their differences from Hutterites in a number of fields. Mennonite groups have got their own schools which are either private or are related to church customs in any way. The groups believing on conservative thoughts amongst the Mennonites have their own schools as well as their staff for teaching and their own syllabuses as well. Most of the times, this teaching staff is women who are young and not married. Hutterites have got their schools in the form of a house in the colony where they live. Hutterites don’t like to send children to schools outside their colony. The schools in Hutterites colonies are responsible for providing the minimum amount of education according to the laws of State or Province. Unlike Mennonites, the Hutterites indulge teachers in their schools from outside. These teachers are selected after making sure that they would be able to teach basic subjects as well as English. | <urn:uuid:718c2dfb-a23b-4da3-961e-0fab80dbabd4> | CC-MAIN-2016-26 | http://www.differencebetween.com/difference-between-mennonites-and-vs-hutterites/ | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783403502.46/warc/CC-MAIN-20160624155003-00043-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.979996 | 700 | 3.0625 | 3 |
Tonight's harvest moon got its name because it is the full moon nearest the autumnal equinox, which means it extends the hours of light into the evening, helping harvesters with a long day's work. Full moon phase begins at 4:12 p.m.
About 65% of the human body is water, and because the full moon affects tides, it's no wonder people also feel a change. So says Connie Freeman, above, a shaman at Beyond Reality in Canoga Park who is also a behavioral therapist. "More people definitely call me in crisis on a full moon for a reading," she said. "It's almost hormonal."
The reason animals may act differently during a full moon is associated with the lunar lighting, said CSUN animal psychologist Donna Hardy. "There might be more activity among predators because they can see," she said. "It's not some mysterious energy thing. Actually, it's kind of boring." | <urn:uuid:a25a9854-4632-4db7-b26f-e196dd84565b> | CC-MAIN-2016-26 | http://articles.latimes.com/1998/oct/05/news/mn-29503 | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783398628.62/warc/CC-MAIN-20160624154958-00027-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.965141 | 192 | 2.8125 | 3 |
The violence subsided within several days, but worried federal officials in Washington watched Maryland with concern. If Maryland went out of the Union, the city of Washington -- the federal capital -- would be surrounded by Confederate states. Although there was strong Unionist sentiment in Maryland -- particularly among the farmers of Western Maryland and the business community in Baltimore -- the government in Washington decided it could take no chances. President Lincoln authorized the suspension of the writ of habeas corpus. Gen. Benjamin F. Butler occupied Annapolis, seized the railroad between that city and Washington, and then on May 14, in a thunderstorm, occupied Baltimore. Maryland was saved for the Union, whether it liked it or not.
In Prince George's County, there was great sympathy for the South. It is not hard to understand why. Despite the sectional division within Maryland, Prince George's County in 1861 was part of the South. It had a plantation economy and a population that was more than half slave. There was virtually no abolitionist sentiment here -- in the presidential election of 1860, Abraham Lincoln received just one vote from all of Prince George's County! The leaders of our social and public life -- the old gentry -- were all slaveholders and very much Southern-oriented. When it became evident that Maryland would not secede from the Union, scores of young men went South to fight for the Confederacy.
This sympathy for the South did not necessarily mean that Prince Georgeans wanted Maryland to secede, however. Prince George's was a conservative place, and secession was a radical step. Furthermore, county citizens could be sure, located so close to Washington, that their county would be turned into a battleground if Maryland did try to secede. There were firebrands in the county who advocated secession, but three times they were defeated at the polls by more moderate forces. The sentiment of the voters seemed to be: let the South go in peace, but we will stay in the Union.
The first test of secessionist sentiment in the county took place in February 1861, before Fort Sumter. All across the South, state conventions were being held to decide the question of secession or union. Such a convention was to be held in Maryland, and Prince George's County was to elect four delegates. But instead of sending the delegates, Prince Georgeans voted-by a narrow margin-against holding the convention at all. The Planters' Advocate complained that "the least exertion on the part of the friends of the movement, could have elicited a vote that would have overwhelmed the opposition," but the complaint was too late. The state convention, when it met in March, did not decide for secession anyway.
The second electoral test came in June, in special congressional elections. There were two candidates seeking to represent this district in Congress: Charles Benedict Calvert of Riversdale and Benjamin Gwinn Harris of Saint Mary's County. Calvert, though a slaveholder, was a Unionist. Harris was the nominee of the Southern Rights Convention. Calvert carried the county as well as the entire district and went to Congress. His credo was brief: "If Maryland has grievances under the general government she should seek a remedy for them in and not out of the Union." ( National Intelligencer ). He denied that any state had the right to secede.
The third and final contest of 1861 was in the fall, with the general election for state and county offices. Two slates were presented to the voters of Prince George's County -- a Unionist slate and a Peace and States' Rights slate. The Unionist ticket was led by its state senate candidate, Dr. John H. Bayne, the respected physician from Oxon Hill, and a slaveholder. The Peace and States' Rights ticket was led by Oden Bowie, an equally respected planter from Collington. The Unionists were victorious at the polls. Again, The Planters' Advocate complained that "Numerous rumors of intended [military] interference, not only prevented a full turnout of the people, but, we have no doubt, affected the course of many who did vote." The total vote was off some from the previous general election, but not dramatically. Whether "rumors of interference" could make people change their votes is debatable.
More than 120 years after the war, it may be hard to understand why Prince Georgeans, on the one hand, sympathized with the South, but on the other hand, voted for the Union for themselves. The entire issue hinged on the question of the preservation of slavery as an institution. As long as slavery was not threatened, Prince George's County would not move to secede. In the first critical year of the war, it must be remembered, the government in Washington made it clear that Maryland and other border states could keep their slaves if they would remain in the Union. The war against the South, in 1861, was a war against rebellion, not slavery. Furthermore, Unionist candidates in this county were not Republicans (there were none here then), but slaveholders themselves, often from the county's oldest families. Finally, Prince Georgeans would not have to fight against the South if they did not want to. There was no draft in the first year of the war, and even after one was begun, substitutes could be found elsewhere in the state to go in the draftee's place. But above all, as long as there could be both Union and slavery, the collective preference of Prince Georgeans, as expressed at the polls, was to stay in the Union.
When the war began, Washington was an undefended city. Many of the troops called up in the first months of the war did not go off to fight, but rather stayed in and around Washington and Maryland to protect the capital. There were soldiers all up and down the Baltimore and Ohio rail line to Baltimore, the rail link to the North; at Fort Washington on the Potomac; in camps throughout the District of Columbia, as well as Bladensburg; and in a ring of forts hastily built surrounding the city. Most of these new forts, such as Fort Dupont, were within the District of Columbia, but one, Fort Lincoln, was partially in Prince George's County, and another, Fort Foote, was entirely in the county, high above the Potomac on Rozier's Bluff, opposite Alexandria.
The Union soldiers who came to Washington often recorded their impressions of Prince George's County. Despite the votes for Unionism, the county had a pro-Southern reputation because of its slave system and lack of enthusiasm for the war. Warren Handel Cudworth, who wrote the History of the First Massachusetts Infantry (1866), recorded his thoughts on a march through the county early in the war: "The march [from Bladensburg] commenced ...and continued, without opposition, through a semi-hostile country until night, when the soldiers bivouacked in an oak-grove, not far from the quaint old town of Marlborough.... The people were moderately disunion or non-committal in their sentiments, but emphatically desirous...to be left alone. No arms or uniforms were found among them, although several houses were searched from cellar to attic, and the regiment moved on." The people of Bladensburg had been more to his liking: "Most of its inhabitants were loyal to the Union, although not so outspoken, on account of threats and insults from secessionists, as they would have been in New England."
As the war dragged on and became bloodier and bloodier, though, the sentiment of the citizenry here swung away from Unionism toward fuller support of the South. By then, however, the question of Maryland's secession was no longer a live one. The fatal blow to the cause of Unionism in this county came when the Lincoln administration finally linked the winning of the war with the freeing of the slaves. The county Unionists protested that "as Union men, we are not only opposed to emancipation in this state, but even to all agitation of the question, [even though] our devotion to the Union increases with its perils." (Baltimore American, September 3, 1863). But their protests were to no avail. They were beaten handily in the local elections of 1863, and a government openly hostile to President Lincoln and the war effort was installed in Upper Marlboro.
What of the blacks in Prince George's County during the Civil War? When slavery was abolished in the District of Columbia in April 1862, a good many fled there to freedom. If the complaints of county officials are a good gauge, the slaveholders saw it as a major problem. Many slaves also escaped bondage by enlisting in the Union Army. Charles Branch Clark, in an article in the Maryland Historical Magazine in 1946, reported that Oden Bowie lost seventy slaves to enlistment in 1863. Ironically the Emancipation Proclamation did not free the rest of the slaves here, as it applied only to states in rebellion-and Maryland had not seceded. A new state constitution-passed narrowly by the Maryland voters (but rejected in Prince George's County) -- eventually freed the Maryland slaves on January 1, 1865. The old plantation system, already in disarray because of the war and so many runaway slaves, received its death blow.
There were no battles in Prince George's County during the Civil War, although the Union Army was always present, guarding the rail line, marching through the countryside, and watching from the forts around Washington. Once, however, a sizeable Confederate force entered Prince George's. It happened in July 1864, during Jubal Early's last Confederate invasion of Maryland. Early dispatched four hundred cavalrymen under the command of a Marylander, Gen. Bradley Tyler Johnson, to cut rail communications north of Baltimore and then between Baltimore and Washington. The Confederates did their work here on July 11 blowing up the rail line at Beltsville and cutting the telegraph wires. They then camped for the night at the Maryland Agricultural College (now the University of Maryland). The Rossborough Inn was turned over to General Johnson for use as a headquarters. A legend persists that a ball was held at the college that night, a ball attended by all the Confederate officers, the college faculty, and the pro-Southern gentry of Prince George's County. It may never be known whether there is any truth behind the legend of the "Old South Ball," but the story was repeated time and time again in the decades after the war. The next day Johnson and his men rejoined the main body of Early's forces for the unsuccessful attack on Fort Stevens. Georgia Avenue passes by the old fort now; the battle there was the only one to take place within the District of Columbia.
This history of the Civil War in Prince George's County will end with the story of the hero of the Southern cause here, Walter (Wat) Bowie. Wat Bowie was an officer in the Confederate Army, a captain in Mosby's Rangers. His father was W.W.W. Bowie, the agriculturalist; his mother was Adeline Snowden Bowie. During the war, Bowie returned to the county several times, both to gather information and to visit his family. Effie Gwynn Bowie writes in Across the Years in Prince George's County that the federal government put a price on his head. He was captured once and imprisoned, but escaped before he could be executed. Mrs. Bowie relates another story; that while visiting relatives once, he escaped capture by disguising himself as a slave woman and brazenly walking past Union soldiers searching the property. His luck ran out, however, in 1864. On a foray into Maryland, Bowie and his men raided a store in Sandy Spring, Montgomery County. They were pursued by the locals, who caught up with them near Rockville. Shots were fired, and Bowie fell, mortally wounded. His brother Brune stayed with him and was captured. Wat Bowie was buried at the family home Willow Grove, near Holy Trinity Church, Collington. He was twenty-seven. It is said that his mother never spoke after his death. She died a few months later.
The end of the war and the freeing of the slaves brought great changes to Prince George s County. The old way of life for the slaveholders came to an end; freedom at last came to the slaves. In two hundred years of settlement, Prince George's County had become the richest, most productive plantation county in Maryland. That was over. A new age would begin. | <urn:uuid:5d3a930c-6435-433f-874a-f18377d78e9d> | CC-MAIN-2016-26 | http://www.pghistory.org/PG/PG300/civilwar.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783399428.8/warc/CC-MAIN-20160624154959-00143-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.981777 | 2,564 | 3.78125 | 4 |
The New York State Education Department is making it clear that the state tests to be given to third- through eighth-graders next month are going to be different -- and difficult. The tests are tied to the new Common Core curriculum and, the state says, require deeper thinking skills and more ability to apply math facts to real-world problems.
Can you meet the challenge we are setting for our children? Today and for the next eight days, you can take a crack at a sample fifth-grade math question.
Good luck and don't worry -- only your pride is at stake.
Question 1: Which mathematical expression is equivalent to the number sentence below?
Subtract 15 from 45, and then divide by 3.
A. 15-45 ÷ 3
B. (45-15) ÷ 3
C. (15-45) ÷ 3
D. 3 ÷ (45-15)
So far, so good? Tune in Monday for Question 2.
Contact Paul Riede at [email protected] or 470-3260. Follow him on Twitter at @PaulRiede. | <urn:uuid:66c5c14d-4881-4a27-b4ea-a590ed386a1a> | CC-MAIN-2016-26 | http://www.syracuse.com/news/index.ssf/2013/03/could_you_pass_the_new_fifth-g.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783398873.39/warc/CC-MAIN-20160624154958-00118-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.922818 | 235 | 3.328125 | 3 |
Cornelius loved reading in kindergarten. Math was easy in first grade. “You could say two numbers, and I would subtract ‘em and multiply ‘em and add ‘em in my head, give you three answers in a matter of seconds.”
Why did he drop out of high school? In Butterflies in the Hallway, part of the Education Trust’s Echoes from the Gap series, Brooke Haycock uses interviews and school records to tell Cornelius’ story of failure, disengagement and more failure.
Cornelius had trouble reading “bigger books” in fourth grade. He was too embarrassed to ask for help. By fifth grade, he was getting in trouble with a friend who also was struggling. It “felt better than feeling stupid alone,” he told Haycock
At a middle school where violence was common, Cornelius began cutting gym class to avoid older boys who he feared would beat him up.
“He never skipped math, the class where he always felt smart,” but he started cutting classes that required reading.
His friends, other “lost boys,” would “just run around the school.” Sometimes he got detention, but nobody tried to find out why he was skipping.
The youngest of nine children, Cornelius was raised by his grandmother. The summer after sixth grade, she died. “I just stopped caring. I felt like there was no one there to enforce rules on me or to make me sit down and do my homework. No one to care.”
He lived with his aunt and two brothers for several years.
Recognizing Cornelius’ artistic talent, a new principal invited the seventh grader to lead the school’s mural painting team at a district competition. Cornelius was thrilled.
But he couldn’t read well enough to do school work. “I started getting further and further behind. And I just lost interest. I felt like I was too far behind.”
He got into fights, which led to suspensions.
In high school, he was diagnosed as emotionally disturbed and placed in special ed classes. Then he was suspended for cutting class.
Some of Cornelius’ teachers tried to help, but he’d given up.
He moved to a group home and a new school for his second try at ninth grade. He failed again. At 17, still in ninth grade, Cornelius dropped out.
If he’d received help with his reading skills in third or fourth grade, could Cornelius have been saved? | <urn:uuid:d70fe570-c206-4210-8cfc-d78db9f8015b> | CC-MAIN-2016-26 | http://www.joannejacobs.com/tag/dropout/ | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783397695.90/warc/CC-MAIN-20160624154957-00154-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.987013 | 540 | 2.71875 | 3 |
Mimicking Mother Nature: Scientists create a fixed-wing flying robot that can slow down and land like a bird
Manoeuvering its wings as it flies through the air, it looks like any normal bird coming in for a landing.
But, rather than the snappy handiwork of Mother Nature, this winged one is the first robot ever created that is capable of 'perching' - or landing like a bird.
The micro aerial vehicle (MAV) managed to slow itself down and perch on a human hand, even though it was thrown off a ladder with force.
On a wing and a flare: The micro aerial vehicle (MAV to its friends) is seen here in time-lapse composite photos. Its wings change shape and angle so that the MAV slows down and drops onto its landing target
An astonishing video posted on YouTube shows it swooping in and easing itself down using its wings after being thrown by one of the researchers.
The MAV was inspired by the natural design of a bird’s wings, which are capable of manoeuvering to a very precise level.
By shaping their wings, birds can slow themselves down so they stall above a given point - gracefully dropping down onto a perch or ledge.
Wings up: Five different control zones allows the MAV to do what it does. With its wings high, abaove, it has greater manoeuverability at low speeds
Wings down: A rudder-less tail moves up and down to control the pitch (descent/climb) of the craft, and the wings can move independently for greater control while in flight
Helicopters employ a similar principle when landing. Called 'flaring', pilots angle the rotors so that the machine dramatically slows down before landing.
The manoeuvre was thought to be impossible for fixed-wing craft - until now.
Furthermore, the MAV does not have a vertical tail shape like conventional aircraft. Instead it has articulated wings and a pitching tail that work together to let it glide into position before making sure it lands on its target.
The researchers, from the University of Illinois, said this was challenging because it required a high level of accuracy - and the bird only has a short time to adjust before landing.
Coming in to land: The MAV zeros in on its target - for this test it is a human hand. Other tests have included the craft landing on fixed perches and office furniture
The robots could one day be used for a variety of purposes, such as high-tech toys for children, and could lead to the development of vertical-landing aircraft.
Soon-Jo Chung, an assistant professor in the Department of Aerospace Engineering at Illinois, said: ‘We believe we have the first demonstration of autonomous/robotic flight of a bird-like micro aerial vehicle perching on a human hand’.
Aditya Paranjape, a post-doctoral scholar who also worked on the project, added: ‘We have developed an articulated-wing-based concept for an agile robotic aircraft inspired by birds. Of all manoeuvers executed by flapping wing aircraft in a gliding phase, a perched landing is arguably the most challenging.’ | <urn:uuid:7b255143-60cc-46d9-97ca-eefab57dcea4> | CC-MAIN-2016-26 | http://www.dailymail.co.uk/sciencetech/article-2138418/Mimicking-Mother-Nature-The-flying-robot-slow-land-like-bird.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783396872.10/warc/CC-MAIN-20160624154956-00111-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.952212 | 673 | 3.3125 | 3 |
Complete ophthalmic examination in the horse generally requires sedation and an auriculopalpebral nerve block.
Before sedation, the symmetry of the head and globes are examined followed by evaluation of the menace response and palpebral reflex.
After sedation and akinesia of the auriculopalpebral nerve, the adnexal structures, cornea, and pupillary light reflexes are examined.
Diagnostics, including fluorescein staining, cytology, culture, Schirmer tear test, and tonometry, are often indicated at this time. The examination is continued with evaluation of the anterior segment, mydriasis, and indirect and direct ophthalmoscopy. Subpalpebral lavage systems are often required for the treatment of painful corneal conditions. Subpalpebral lavage systems are relatively easy to place and are relatively problem-free if maintained properly.
- To perform the menace reflex, the examiner abruptly moves a hand toward the horse's eye. The appropriate response is to blink the eye, and perhaps move the head away. This helps us to determine if your horse can see.
- To perform the palpebral reflex, the examiner lightly touches the eyelid, and the horse should close his eye. This helps to determine if the horse has skin sensation, and if he has control of the muscles of the face.
- To perform the pupillary light reflex, the examiner brings the horse into dim lighting, and shines a penlight first into one eye, then the other. The pupils of the eye should constrict. This helps to assess pathways in the brain that control eye function.
Diseases of the equine eye
- Recurrent uveitis
- Keratomycosis - fungal eye infection
- Keratoconjunctivitis sicca - dry eye
- Congenital stationary night blindness
- Ocular squamous cell carcinoma
- Corneal ulcer
Breed specific diseases
|Appaloosa||Ocular Squamous cell carcinoma, Congenital stationary night blindness (CSNB), Congenital cataract, Glaucoma, recurrent uveitis, Optic disc colobomas|
|Belgian draft horse||Aniridia and secondary cataract|
|Morgan||Cataract - nuclear, bilateral, symmetrical, and non-progressive|
|Quarter horse||Congenital cataract, entropion|
|Rocky mountain horse||Anterior segment dysgenesis, congenital miosis, and corpora nigra and iris hypoplasia, macrocornea, ciliary cysts, cataract, lens luxation, retinal dysplasia, retinal detachment|
|Thoroughbred||Congenital cataract, microphthalmia associated with multiple ocular defects, retinal dysplasia associated with retinal detachments in some cases, entropion, progressive retinal atrophy|
|Standardbred||Retinal detachments, congenital stationary night blindness|
|Paso fino||Congenital stationary night blindness, glaucoma|
|American saddlebred||Cataract, keratomycosis| | <urn:uuid:56108df7-d966-4080-93f3-bbbe61a58d71> | CC-MAIN-2016-26 | http://vetbook.org/wiki/horse/index.php/Ophthalmology | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783408828.55/warc/CC-MAIN-20160624155008-00065-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.821239 | 672 | 2.765625 | 3 |
Riga is located at the site of an ancient settlement of the Livs, an ancient Finnic tribe, at the junction of the Daugava and Ridzene (Latvian: Rīdzene) rivers. The Ridzene was originally known as the Riga River, at one point forming a natural harbor called the Riga Lake, neither of which exist today. Some believe that the name of the river gave Riga its name.
The modern founding of Riga is regarded by historians to begin with German traders, mercenaries and religious crusaders who arrived in Latvia in the second half of the 12th century, attracted by a sparsely populated region, potential new markets and by the missionary opportunities to convert the local population to Christianity.
Bishop Albert was proclaimed Bishop of Livonia by his uncle Hartwig, Archbishop of Bremen and Hamburg in 1199. He landed in Riga in 1201 with 23 ships and more than 1500 armed crusaders, making Riga his bishopric. He established the Order of Livonian Brothers of the Sword (later a branch of the Teutonic Knights) and granted Riga city rights in that same year. Albert was successful in converting the King of the Livs, Caupo of Turaida, to Christianity, although, as related in the Chronicle of Henry of Livonia ("Hencricus Lettus"), it took him three decades to gain full control of Livonia (German Livland). Riga as well as Livonia and Prussia came under the auspices of the Holy Roman (German) Empire. It was not until much later, at the time of Martin Luther, that Riga, Livonia and Prussia converted to Protestantism.
As the influence of the Hansa waned, Riga became the object of foreign military, political, religious and economic aspirations. Riga accepted the Reformation in 1522, ending the power of the archbishops. With the demise of the Teutonic Knights in 1561, Riga enjoyed twenty years as a free city. In 1581, Riga came under the influence of the Polish-Lithuanian Commonwealth. Attempts to reinstitute Roman Catholicism in Riga and southern Livonia failed as in 1621, Riga and the outlying fortress of Daugavgriva came under the rule of Gustavus Adolphus, King of Sweden, who intervened in the Thirty Years' War not only for political and economic gain but also in favor of German Lutheran Protestantism. During the Russo-Swedish War, 1656-1658, Riga withstood a siege by Russians. Riga remained the second largest city under Swedish control until 1710 during a period in which the city retained a great deal of self-government autonomy. In that year, in the course of Great Northern War, Russia under Tsar Peter the Great invaded Riga. Sweden's northern dominance ended, and Russia's emergence as the strongest Northern power was formalized through the Treaty of Nystad in 1721. Riga was annexed to Russia and became an industrialized port city of the Russian empire, where it remained until World War I. By 1900, Riga ranked the third in Russia after Moscow and St. Petersburg in the number of industrial workers.
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Critiques | Translate
MIG13 (0) 2006-06-17 13:41
Hi, George! As usual, a nice pic, with a good perspective and a great resolution (it's possible to notice the different colours of each building). Thnks for sharing! Greetings from Rio! Miguel.
Andrzej_HHH (2480) 2006-06-17 13:41
Very beautiful composition of colors with high quality sharpness. Good work! Regards. Andrzej
aralda (1240) 2006-06-17 13:45
It's nice to see that these houses are so well taken care of. The colors are very nice, and it's good to see that no paint is peeling off or that the stucco is coming off, as is the case, unfortunately, with many turn-of-last-century houses here in Transylvania.
Dragonheart (8414) 2006-06-17 14:41
Beautiful colours, like your pov. beautiful shot.
Buin (42466) 2006-06-17 15:41
What a really lovely scenery! This street seems so cosy and calm...and the colours! Thank you for showing this - I like it very much, especially the colours and the point of view!
Greetings from Germany!
talatbay (2424) 2006-06-17 16:29
Hi George ,
colourful and nice shot.
pasternak (15185) 2006-06-17 18:39
Very colourful indeed, and this compensates for the lack of light and not a 100% perfect composition. Maybe the POV could be a little bit to the right, now the angle of the buildings on the left is too tight...
But what is nice about the shot is that it gives the viewer the exceptional feeling of the old Riga.
Thanks for sharing
InasiaJones (31566) 2006-06-17 19:10
Very pleasing view of this cozy street with colouful and interesting architecture.
Thanks for making us discovering Riga.
worldcitizen (8570) 2006-06-17 19:23
I really like the view of this cobblestone street. The architecture is beautiful, and I like the way there are also buildings at the end of the street, giving us a view from two perspectives. The colors are wonderful. I love the warm and historic feeling that streets like this convey.
alana (2625) 2006-06-17 20:25
Excellent composition with rich colors, interesting point of view, architecture details, contrast and sharpness. Very well captured and seen.
sabyasachi1212 (19779) 2006-06-18 3:41
I am really fascinated by your recent posts on Riga, a capital city so colourful, I could never imagine. This one is brilliant as well.
With Greetings from India
veve (4189) 2006-06-18 4:25
Very good image with many colors!
RGatward (20086) 2006-06-18 15:02
Certainly cooouful, quiet pleasant street, I think it was around the corner from where I stayed last week. I like the man standing there.
agbonavita (0) 2006-06-19 18:59
I like that one! The calm street with few peoples, increse the beauty of Riga.
Thanks for share that incredable city with us George.
quantabeh (5205) 2006-07-30 23:58
beautiful picture of this urban setting. You seem to post really great pictures of home and city blocks. keep up the good job!
krakowiak (4762) 2006-08-01 4:38
This is a very good photogarphy, good balanced with a nice colours. It shows that you don't need beautyful weather to take a great photo. These colorful houses look fabulous here and You've showed this in a fantastic way!
danyy (0) 2006-08-08 12:10
on peut dire que tu fais fort dans la qualité.
Non seulement le cadrage est parfait, mais aussi le panel de couleurs bien rendu par des lumières bien dosées.
Vraiment une photo qui donne envie de visiter une ville, qui plus est très propre et nette.
Un tout bon travail.
With my best regards.
benkrut (2407) 2006-08-10 23:06
A narrow street, tall colourful buildings, small cafes, the artist painting on the street - this is an image of an old town in many cities in Europe. Riga, as we can see above, is one of them.
Very nice shown.
wanna_yu (0) 2006-08-15 7:00
Lovely view of Riga, full of colours. Excellent composition and perspective, very very nice work :)
John_F_Kennedy (43665) 2006-09-12 11:18
Wowo - that is the street I went along in spring. Beautiful capture. Great contrast and sharpness.
salvator (19110) 2007-01-23 4:46
A beautifull place, with beautifull colors and very nice pov and composition.
Best regards. Salvator.
danos (97377) 2007-04-22 13:43
i like these old colourful houses.The architecture is beautiful,and the houses in the and of the street create a sense of depth.Excellent the light,the details and the contrast.Well done.
- Copyright: George Rumpler (Budapestman) (82620)
- Genre: Places
- Medium: Color
- Date Taken: 2005-08-00
- Categories: Daily Life, Architecture, Artwork
- Photo Version: Original Version
- Theme(s): Colours from Europe, Magnificent architectural memories from Europe [view contributor(s)]
- Date Submitted: 2006-06-17 13:31
- Favorites: 1 [view] | <urn:uuid:638e4fbe-dbcd-4f73-a958-069337880825> | CC-MAIN-2016-26 | http://www.trekearth.com/gallery/Europe/Latvia/Central/Rigas/photo405452.htm | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783392159.3/warc/CC-MAIN-20160624154952-00158-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.908662 | 1,987 | 3.5625 | 4 |
Part 1: Chapters 1-4
1. "The Prophets" was written for which religious groups?
(a) Jews and Muslims.
(b) Christians and Muslims.
(c) Jews and Christians.
(d) Jews and Orthodox.
2. The author describes what era in the Old Testament?
(a) Ancient prophets era.
(b) Babylonian exile era.
(c) Prophetic era.
(d) Early Christian era.
3. The author states that a prophet looked at things that seemed what to other people?
4. The prophets were outraged because of what?
(a) The king's edicts.
(c) People's lack of understanding.
5. Prophets were hypersensitive to what?
(a) Expensive habits.
(b) Religious fanatics.
(c) People calling them crazy.
(d) Things that offended God.
6. Prophets rebuked the inhabitants of cities for things that others would have called what?
7. Before Amos was called by God what was his job?
(b) Carpet maker.
8. How did Amos describe God's voice calling to him?
(a) As a whisper in the night.
(b) As a small nagging thought.
(c) As a lion's roar.
(d) As a gentle breeze.
This section contains 4,093 words
(approx. 14 pages at 300 words per page) | <urn:uuid:779ff6e2-e7eb-4e7c-b2db-a35538a332e2> | CC-MAIN-2016-26 | http://www.bookrags.com/lessonplan/the-prophets/multiple.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783397748.48/warc/CC-MAIN-20160624154957-00117-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.927443 | 314 | 3.4375 | 3 |
Jewish Immigration to Escape Persecution in Bavaria - January 27
- 2016 27 Jan
After Spain's monarchs sent Columbus on his voyage they drove Muslim forces out of Spain, and also Jews. Many Jews fled to Portugal and then to Amsterdam, where some sailed with Dutch merchants to South America. When Spain and Portugal attacked there in 1654, twenty-three Jewish refugees, on the French ship Sainte Catherine, escaped to New Amsterdam. Governor Stuyvesant tried to evict them, not letting them worship outside their homes. In 1664, New Amsterdam became New York and the first synagogue was allowed to be built in 1730. Jewish population grew to a remnant of 2,000 during the colonial era with just 7 synagogues from New York to Savannah. Beginning in 1830, Ellis Island saw 250,000 Jews immigrate to escape persecution in Bavaria. In the 1880's, over 2 million Jews fled Russia's pogroms to America, making the U.S. population about 2 percent Jewish. Woodrow Wilson wrote: "Whereas in countries engaged in war there are 9 million Jews, the majority of whom are destitute of food, shelter, and clothing; driven from their homes without warning...causing starvation, disease and untold suffering- Whereas the people of the U.S. have learned with sorrow of this terrible plight, I proclaim JANUARY 27, 1916, a day to make contributions for the aid of the stricken Jewish people to the American Red Cross." | <urn:uuid:c09176d9-6485-4d44-ab7d-03c6e8ab6452> | CC-MAIN-2016-26 | http://www.crosswalk.com/newsletters-only/american-minute/jewish-immigration-to-escape-persecution-in-bavaria-january-27.html | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783404382.73/warc/CC-MAIN-20160624155004-00001-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.94591 | 303 | 3.203125 | 3 |
Disorders and Treatment
- Mental Illness
- Bipolar Disorder
- Mood Disorders
- Borderline Personality
- Mental Health Diagnosis
- Mental Health Treatments
- Alternative Meds
- Case Studies
Isolation and loneliness tend to make difficult situations even worse. As social beings, we seek the company, approval, and support of others, especially during challenging times.
When dealing with depression, fighting the urge to be alone is vital to your recovery. A friend or family member can help you stay motivated and avoid relapsing by reminding you of the reasons why you deserve a better way of life.
The nature of depression can make it difficult to reach out for help. Just the thought of discussing your feelings with a close friend or family member may seem exhausting, but the result will be well worth the extra effort.
If you’re ashamed of your mental state, don’t be. Depression affects more than 350 million people around the world, according to the World Health Organization. If you feel guilty for neglecting your relationships, apologize. Your loved ones will likely appreciate your reaching out to them and want to help you overcome depression.
Confide in trusted friends and family members. Explain how you feel and what you’re going through, and don’t be afraid to ask for help. Relationships with others can provide the strength and stability you need to successfully get through this tough time.
Attend as many social events as possible. You may not feel comfortable going out when you’d rather stay home, but being around other people can help you feel less depressed.
Join a support group. Discussing your thoughts and feelings with other depressed individuals can help you realize that you aren’t alone. Support groups allow you to share your experiences, encourage one another, and give and receive advice.
Photo by John Nyboer
The information provided on the PsyWeb.com is designed to support, not replace, the relationship that exists between a patient/site visitor and his/her health professional. This information is solely for informational and educational purposes. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Neither the owners or employees of PsyWeb.com nor the author(s) of site content take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading this site. Always speak with your primary health care provider before engaging in any form of self treatment. Please see our Legal Statement for further information. | <urn:uuid:95d89402-a007-4c19-beda-3754329294b6> | CC-MAIN-2016-26 | http://www.psyweb.com/articles/depression/break-out-of-self-isolation | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783396106.25/warc/CC-MAIN-20160624154956-00067-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.931983 | 533 | 2.65625 | 3 |
Dr Fred Sanger is the fourth, and only living, person to have won two Nobel Prizes. The first Nobel came from Sanger’s elucidation of the amino acid sequence of insulin in 1951. This discovery showed that proteins have a defined chemical composition as opposed to the amorphous composition that was commonly assumed at the time. The second prize came from his creation of the dideoxy chain termination, or “Sanger Method”, of DNA sequencing that was eventually used to sequence the human genome. In addition to the Nobel, Sanger was the recipient of many other prestigious awards for his groundbreaking work. However, one honor that the Englishman did refuse was knighthood, as the ever modest Sanger preferred not to be called ‘Sir’. “A knighthood makes you different, doesn’t it, and I don’t want to be different. But I did accept an Order of Merit, which is higher, so I suppose there’s a bit of snobbery there,” Sanger said. | <urn:uuid:7e9074e8-be00-4814-a654-c5ebb076e253> | CC-MAIN-2016-26 | https://www.idtdna.com/pages/decoded/decoded-articles/mixed-bases/decoded/2011/09/12/nobels | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783395620.9/warc/CC-MAIN-20160624154955-00078-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.985397 | 221 | 2.703125 | 3 |
Thermal imaging is not new to the electrical industry; for several decades, a principal commercial application of thermal imaging has been for the inspection of electrical systems by performing infrared scans of connections, fuses, junction boxes, switchgear and other electrical components. Results of thermal sweeps are documented by digital images that can be downloaded to a computer for further analysis and saved as records of the inspections.
Compact, handheld infrared cameras with the sensitivity to make temperature measurements with extreme accuracy are used to sweep electrical installations for temperature differences caused by bad connections, load imbalances, overloaded transformers and other deviations within a system. Overheated components or those that are breaking down can be invisible to an electrician but are immediately apparent to trained thermal imaging specialists using infrared cameras.
Detecting and correcting such problems can avert fires and shutdowns that can have catastrophic consequences for manufacturing plants, commercial organizations and government facilities.
An organization’s information communication technology (ICT) infrastructure is an indispensable element in its operations, regardless of what an organization’s product or service is or even whether an organization is public or private. Many data centers operate 24 hours a day, seven days a week and require reliability in the high nines (nine 9s means a system must be operable 99.9999999 percent of the time).
While no two data centers are exactly the same, each has the same basic components, including the utility transformer, standby generator, transfer switch, main switchboard, uninterruptible power supply (UPS), power distribution units (PDUs) and server racks. Because precise temperature control is necessary in the data center, the facility’s heating, ventilating and air conditioning systems are critical.
“Every component in the data system is interconnected and dependent on the others,” said Paul Twite, thermographer, Fluke Corp., Everett, Wash. “They can be viewed as a series of dominoes—if one goes down, the others fall. Electrical components of a data center are different than other systems; a failure takes a lot with it as other failures occur.
Because a data center’s components and systems within the larger network system operate on electrical power, thermal imaging is a primary method of inspection for maintenance. Infrared thermal scans of components is encouraged and, in some cases, mandated by most of the insurance carriers covering data centers.
When thermal image inspections uncover power-related problems—often requiring immediate attention—electrical contractors make repairs, but typically electrical contractors have not made the infrared scans to diagnose potential problems.
“It traditionally has not been common for electrical contractors to perform the scans,” Twite said. “Although, some contractors do outsource the scans to thermographers.”
However, Twite believes electrical contractors are becoming aware of thermography’s potential. “Today, there is a fairly small group of electrical contractors active in data center work. But we see a growing awareness in the industry, and more electrical contractors of all sizes are beginning to add thermal imaging to the services they offer,” he said.
David Francoeur, director of marketing for FLIR Systems, Wilsonville, Ore., believes thermal imaging for data center clients has untapped potential for electrical contractors. “We don’t have statistics documenting how active electrical contractors are in thermal imaging data center work, but we believe there is room for a lot of growth,” he said.
Francoeur said thermal-imaging scans of data center components may be done by personnel working for the company operating the data center and more often by infrared consultants.
Francoeur agreed that electrical contractors are beginning to get into the thermal imaging market. “And not just high-end contractors; we see small- and medium-size electrical contracting companies expanding into the field.”
Such a decision makes sense, Francoeur said. “When electrical problems are identified by the infrared scans, the electrical contractor is able to immediately address the issue,” he said. “In a way, the contractor is being paid to find new work. In addition, having the capability of performing thermal imaging in data centers gives the contractor an added competitive edge for business. We are seeing some contractors actively promoting thermography on their vehicles, in advertising and mailers. It is a good time to bring infrared into the business.”
For the data center owner, it makes sense to have electrical contractors do infrared maintenance scans.
“Energized medium-voltage equipment can only be opened by qualified personnel,” Twite said. “With licensed electricians on hand during the scans, repairs can be started immediately. If an infrared specialist uncovers an issue, all he or she can do is report the problem, and the data center calls an electrician who must have a new scan done to confirm the problem. That takes time and can be costly.”
Twite said data centers are ranked by reliability of power and density of its servers. System categories include the following:
“Thermal data collection should be repeatable and periodic,” Twite said. “Data collection should be performed while electrical distribution is under heaviest load. I prefer to work ‘downstream’ in a logical path with flow of current. And it is necessary to be vigilant about environmental variables such as temperature, humidity, emissivity and airflow because they can affect infrared scan information.”
For making inspections, Twite has a four-wheeled cart on which he carries the thermal camera, a handheld device to monitor environmental conditions and electrical test tools. He prefers to begin thermal inspections outside at the utility transformer. He makes the following checkpoints on a data center’s basic components:
Twite said most simple data center scans can be completed in a fraction of a day by a proficient technician. Scans of complex data centers can require several days to complete.
Conducting thermology scans of electrical components is not in itself difficult; cameras are compact and easy to use. Training ranges from several levels of certification from basic to full-fledged thermographer. To make and interpret thermal scans starts with training and builds on experience.
“The challenges are collecting good, solid data, understanding what images on the screen represent and make the correct diagnosis,” Twite said. “To do that, the technician must have an understanding of electricity and see scanned images through the eyes of an electrician and understand the physics of what data represents. It is also essential to understand environment variables.” EC
GRIFFIN, a construction and tools writer from Oklahoma City, can be reached at 405.748.5256 or [email protected]. | <urn:uuid:7d7bfce2-6568-49bb-9a93-6aad1a879c0f> | CC-MAIN-2016-26 | http://www.ecmag.com/print/section/miscellaneous/hot-or-not?qt-issues_block=1 | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783397749.89/warc/CC-MAIN-20160624154957-00196-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.929399 | 1,381 | 2.796875 | 3 |
By Mark Ward
BBC News website
The US is in danger of running out of honey bees to pollinate its almond crop - the country's number one horticultural export.
The varroa mite has devastated bee colonies all over the world
February and March are the crucial months for almond growers, as this is when trees blossom and need pollinating.
At this time of year, owners of commercial hives take their valuable cargos to California, where almost 80% of the world's almonds are grown, to service the blossom.
Annually the crop is worth more than $2.5bn and a lot of jobs depend on a good harvest, explains Dan Cummings, one of the directors of California's Almond Board and head of its bee task force.
Currently about 222,000 hectares are under production to grow almonds. Mr Cummings expects this to grow to 330,000 hectares over the next five years.
But, said Mr Cummings, that growth presented a real problem.
"Roughly two-thirds of the bees in the US need to come to California for almond pollination," said Mr Cummings. "Beekeeping in the US is very much migratory."
The danger is that as the demands of almond growers for healthy hives grow, America will simply not have enough commercial colonies available to travel. Bees travel from as far away as North Carolina to California just so they can be used at the key pollination season.
"Last year we were a little short," said Mr Cummings.
Already, he said, demand for colonies was driving up the price that beekeepers charged for renting out their colonies.
In 2004, beekeepers could get, on average, $54 for every hive they sent to almond groves in California. Last year, prices peaked at about $85, and in 2006 there are reports of owners charging more than $150.
Mites stunt bee growth and make them vulnerable to disease
To make matters worse, American bees are suffering a resurgence of debilitating attacks from the varroa mite. These tiny parasites stunt the growth of bees, sap hive resources and slowly kill off the colony.
Unfortunately, said Mr Cummings, bee colonies badly affected by varroa typically collapsed at about the same time as almond trees came into flower.
While chemical treatments can help manage the problem, many pesticides have been so widely used that some mites have developed resistance.
Finding a better way to manage mites had become a pressing problem, said Mr Cummings, because of the tight relationship between the health of beehives and the size of the almond crop.
American beekeepers are now turning to a British development to help them tackle resistant varroa mites.
Developed by Vita Europe, the thymol-based treatment is derived from thyme, and vapours from oil extracted from the herb have proved useful in killing the varroa mites.
Dr Max Watkins, technical director of Vita Europe, said: "Thymol works in a very different way from traditional pesticides which target specific points on the nervous system."
By contrast, he said, thymol has a much wider effect on varroa physiology.
In tests, thymol had been able to knock out more than 90% of the mites in a colony, said Dr Watkins.
"It's a little more difficult in theory for something to become resistant to that," he added.
Dr Watkins explained that thymol tended to knock out both resistant and non-resistant varroa mites, so beekeepers could use it in rotation with established treatments to keep the numbers of parasites under control.
Vita's anti-varroa treatment is now undergoing certification in the US.
Although certification will come too late for the 2006 almond pollinating season, Dr Watkins expects it to be in wide use to prepare bees for the 2007 crop. | <urn:uuid:826710df-d239-43a8-b70d-715921740dde> | CC-MAIN-2016-26 | http://news.bbc.co.uk/2/hi/science/nature/4780034.stm | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783391519.0/warc/CC-MAIN-20160624154951-00060-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.957251 | 797 | 2.90625 | 3 |
Ecological Threat in the United States
English ivy is an aggressive invader that threatens all vegetation levels of forested and open areas, growing along the ground as well as into the forest canopy. Vines climbing up tree trunks spread out and envelop branches and twigs, blocking sunlight from reaching the host tree’s foliage, thereby impeding photosynthesis. An infested tree will exhibit decline for several to many years before it dies. The added weight of vines also makes trees susceptible to blowing over during storms. English ivy has been confirmed as a reservoir for bacterial leaf scorch (Xylella fastidiosa), a harmful plant pathogen that affects a wide variety of native and ornamental trees such as elms, oaks and maples.
No one has provided updates yet. | <urn:uuid:f3a4cde9-116f-456d-b3b5-8e9470e357b7> | CC-MAIN-2016-26 | http://eol.org/data_objects/22733994 | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783393442.26/warc/CC-MAIN-20160624154953-00183-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.956389 | 163 | 3.5 | 4 |
What was Hitler's true ambition in conquering other nations?
I think I understand the basics of WWII but what was Hitler intending to accomplish by attempting to conquer so much territory? Denmark? France? Russia? Was he truly attempting to bring those countries under the German flag? On a practical level what precedent if any was there of one country being able to conquer so much territory and govern so many unwilling citizens?
This question is in the General Section. Responses must be helpful and on-topic. | <urn:uuid:4e92d578-cd84-4aa4-9f5e-3740c5489f13> | CC-MAIN-2016-26 | http://www.fluther.com/152746/what-was-hitlers-true-ambition-in-conquering-other-nations/ | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783404382.73/warc/CC-MAIN-20160624155004-00124-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.959387 | 100 | 2.65625 | 3 |
In the half century since James D. Watson and Francis Crick pieced out the structure of DNA, research into the double helix has transformed knowledge of development, function, and disease. It has also become a commonplace truth that DNA (or RNA) is the unique sine qua non of any living organism. As such, it comprises a material identifier, a collection of base-pair sequences that provide an individual's signature, independent of the information that any one sequence may encode. While most of the clinical payoffs remain in the future, the chemical specificity of DNA has already affected the world economy and Western society in particular, notably in biotechnology and human identification.
OWNING LIFE The recognition that the control of heredity and development resides in a molecule has greatly expanded the scope of intellectual property protection by allowing patents for living organisms. What is patentable in the United States reflects the patent law of 1793, which declared, in language written by Thomas Jefferson, that patents could be obtained for "any new and useful art, machine, manufacture, or composition of matter, or any new or useful improvement thereof."
With the exception of plants that could be reproduced asexually, which were made patentable by Congress in 1930, living organisms were held to be ineligible for protection because they are natural products. But then along came DNA--and, in 1972, Ananda Chakrabarty, a biochemist at the General Electric Company, who, having bioengineered a bacterium to consume oil slicks, filed for a patent on the living, genetically altered bacterium.
The Patent Office rejected his claim, prompting a battle in the courts. On June 16, 1980, in the case by then known as Diamond v. Chakrabarty, the United States Supreme Court ruled by a vote of five-to-four in Chakrabarty's favor. Chief Justice Warren Burger delivered the majority opinion, enthusing over the broad language that Thomas Jefferson had written into the patent code, and declaring that "the relevant distinction was not between living and inanimate things, but between products of nature, whether living or not, and human-made inventions." Chakrabarty's bugs were new compositions of matter, the product of his ingenuity, not of nature's. They were thus innovative manufactures and, hence, patentable.
During the 1980s, American patents were awarded on a plant and on a mouse. Patents were also allowed on human genes of known function--for example, the gene for insulin--in a form that did not occur naturally but had been derived from DNA by scientific manipulation. As a result, the new biotechnology industry increasingly flourished in the United States, energized by venture capitalists willing to invest heavily in companies that could patent genetically modified organisms as well as genes.
FINDING FAMILY Not long after the court’s ruling, DNA began weighing in on the side of human rights. In 1984, a delegation of five biologists on a mercy mission journeyed to Argentina under the sponsorship of the American Association for the Advancement of Science. One member, Mary-Claire King, then at the University of California, Berkeley, was a veteran of the antiwar protests of the 1960s and a committed believer in using science for social benefit. The delegation hoped to assist the Grandmothers of the Plaza de Mayo in identifying the offspring of their “disappeared” children, arrested during the military dictatorship that had recently ended. The grandchildren had either been taken with their parents or born in prison. While the parents had likely been murdered, the Grandmothers had gathered enough information about their grandchildren to believe that at least 210 had survived, having been given or sold to other families.
To establish identification, King relied at first on human leukocyte antigens (HLAs), comparing this genetic feature of the found grandchildren with those of a few seemingly likely grandparents, their probable connection having been determined by social evidence. However, HLA analysis gave rise to too many random matches to be used for conclusively identifying grandchildren lacking social identifiers, since their HLAs had to be tested against the national database established for all the grandparents.
King turned to mitochondrial DNA (mtDNA), which Allan Wilson, her mentor at UC-Berkeley, had shown to provide reliable evidence of human descent in the maternal line. With PCR, enough mtDNA could be obtained to test the sequence in the highly variable D loop for matches between children and maternal relatives. As of 1992, of the 210 children in question, 50 have been identified; 12 have been found but not matched with a family; 148 are still missing. The national database now includes sequences from the grandmothers' mtDNA. The grandmothers, King noted, derived satisfaction from knowing that, even after they die, "no one will be able to stop the children themselves from looking for their families."
FREEING PRISONERS By the early 1990s, DNA analysis, pioneered in England in 1985, had become an integral feature of the criminal justice system; American prosecutors were increasingly using it to identify and convict criminals. Restriction fragment length polymorphisms (RFLPs) from a suspect could be compared with those found in biological material (notably blood, semen, hair, or skin cells) found at a crime scene. Although its reliability was disputed on scientific grounds for several years, by the mid-1990s DNA analysis had been sufficiently improved to gain wide acceptance in both the scientific community and the courts. Forty-three states now maintain DNA databases of convicted criminals, a resource that assists in identifying the perpetrators of new offenses.
But DNA has acted as an instrument of innocence, too. In 1991, Barry Scheck and Peter Neufeld, both then legal aid lawyers in the South Bronx of New York City, established the Innocence Project, whose lawyers use DNA analysis as evidence to help exonerate people they believe were wrongly convicted. Largely because of the project, which is now located at Yeshiva University's Benjamin N. Cardozo School of Law, DNA analysis had by 2001 resulted in the acquittal and release of 40%--more than 100 prisoners--of inmates tested, many of them on death row. Most recently, its role in the release of the five young men wrongly convicted in the New York City Central Park jogger case dramatically revealed the deficiencies of plea bargaining.
DNA has thus unexpectedly spotlighted a need for reform of criminal justice. Its use in exonerating has exposed serious flaws in the prosecutorial system, especially in capital cases: the shaky reliability of eyewitnesses, the inability of the defendants to afford private lawyers, and the inadequacy of conventional forensic data in establishing identity. Reviews of the death-penalty system have been initiated in nine states, including Illinois, where in February 2000, Governor George Ryan imposed a moratorium on executions pending the outcome of the state's assessment.
Today, DNA analysis with RFLPs and with mtDNA finds ever more uses. It is exploited by adopted children searching for their natural parents, by plaintiffs seeking to prove paternity, and by analysts attempting to identify victims of disasters. In the 1990s, DNA tests linked remains to passengers who died in the crashes of TWA flight 800 and the Swiss Air flight off Nova Scotia, and they helped determine who was buried in the mass graves in Bosnia. After Sept. 11, 2001, expectations ran high that DNA would help identify the remains at the World Trade Center site. King, now at the University of Washington, was not alone in warning that it might be impossible to identify by DNA analysis the badly burned and degraded body parts. Indeed, DNA permitted recognition of only 20% of the 804 people identified by March 2002. Still, as a reporter from San Francisco noted, "Despite its limited success, this mass genetic-matching effort is actually far from pointless.... There's nothing like truth to help people recover from atrocity."
DNA databases may eventually become an agent of homeland security, assisting in the defense against terrorists. Without proper controls, however, these databases could also imperil the right to privacy and undermine civil liberties. Little, if anything, is more personal, or worthy of protection than your DNA.
Daniel Kevles ([email protected]) is Stanley Woodward Professor of history at Yale University.
We apologize for errors introduced by an editor in the article "Ownership and Identity," (Jan 13 2003, page 22). The delegation led by Mary-Claire King that worked with the grandmothers of the "disappeared" children was in Argentina and not in Chile as originally stated. The mention of Pinochet's dictatorship was irrelevant to the story. | <urn:uuid:aee8fb19-0646-4681-a040-93dc021ca503> | CC-MAIN-2016-26 | http://www.the-scientist.com/?articles.view/articleNo/14438/title/Ownership-and-Identity/ | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783393533.44/warc/CC-MAIN-20160624154953-00085-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.967898 | 1,758 | 3.46875 | 3 |
|Scientific Name:||Chaetodon declivis|
|Species Authority:||Randall, 1975|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Pyle, R., Myers, R. & Pratchett, M.|
|Reviewer(s):||Elfes, C., Polidoro, B., Livingstone, S. & Carpenter, K.E.|
Although it has a relatively restricted range, there are no major threats. The population is unlikely to be declining. The species is listed as Least Concern.
|Range Description:||This species is known only from the Marquesas Islands (French Polynesia), Phoenix Islands (Kiribati), and Line Islands (Kiribati and USA) in the South Pacific Ocean (G.R. Allen pers. comm. 2006). It is found at depths of 20-80 m.|
Native:French Polynesia; Kiribati; United States Minor Outlying Islands (US Line Is.)
|FAO Marine Fishing Areas:||
Pacific – eastern central
|Lower depth limit (metres):||80|
|Upper depth limit (metres):||20|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||It is relatively common at depths of 25 to 40 m. The population at Christmas Island (in the Line Islands) is believed to be stable.|
|Current Population Trend:||Stable|
|Habitat and Ecology:||Found on rocky reef and coral reef slopes and steep walls adjacent to sandy bottoms, usually below 20-30 m (G.R. Allen pers. comm. 2006).|
|Use and Trade:||In 2001-2006 it was frequently collected for the international pet trade, however the market has decreased significantly in recent years (R. Pyle pers. comm. 2009).|
There appear to be no major threats to this species. Collection is limited and is not considered to be impacting the global population.
There appear to be no species specific conservation measures in place. This species is believed to be present within a number of marine protected areas.
|Citation:||Pyle, R., Myers, R. & Pratchett, M. 2010. Chaetodon declivis. The IUCN Red List of Threatened Species 2010: e.T165708A6097568. . Downloaded on 27 June 2016.| | <urn:uuid:8a964833-9648-4774-aec0-7fe6633c6e32> | CC-MAIN-2016-26 | http://www.iucnredlist.org/details/summary/165708/0 | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783395992.75/warc/CC-MAIN-20160624154955-00075-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.731295 | 529 | 2.53125 | 3 |
NEW YORK – Usually, physics research starts with a known problem. There are surprises, of course, but they don’t often come from Internet videos, as happened with the case of the mysterious chain fountain.
It started with Steve Mould, a host of science television shows in Britain. Mould, who has a master’s degree in physics from Oxford, seems to be the discoverer of the chain fountain, which he demonstrated in a startling video posted online. In it, he pulls one end of a long chain of metal beads out of a glass container. Once he starts it off, the bead chain continues spilling out of the container on its own, like water or gasoline being siphoned from a tank.
That, in itself, would be interesting enough. But the real surprise is that the chain doesn’t just run over the edge. It rises up in a curve, like a water fountain, as it falls.
“I came across it by accident,” he said. “I was looking for a physical model of a polymer,” a long molecule. He thought a chain of beads would work, and in the process of investigating that possibility he saw a demonstration of plastic beads self-siphoning from a container, tumbling over the edge.
“I thought, ‘I want to reproduce this, but I think metal might look better.’” He tried it, and to his surprise the chain rose like a charmed snake. The video, posted about a year ago, went viral, and John Biggins, a Cambridge physicist, saw it.
He had been talking with another physicist at Cambridge, Mark Warner, about a project Warner was working on, an online course to improve physics education in high school. Biggins brought the chain fountain video to Warner’s attention and they agreed it was an ideal problem to present to students because it involved Newtonian physics, not some extreme variant of string theory or quantum mechanics.
Then they realized that they didn’t actually understand it.
The fountain, said Biggins, which he had never seen before the video, was “surprisingly complicated.” The chain was moving faster than gravity would account for, and they realized that something had to be pushing the chain up from the container in which it was held.
A key to understanding the phenomenon, Biggins said, is that mathematically, a chain can be thought of as a series of connected rods. When you pick up one end of a rod, he said, two things happen. One end goes up, and the other end goes down, or tries to. But if the downward force is stopped by the pile of chain beneath it, there is a kind of kickback, and the rod, or link, is pushed upward. That is what makes the chain rise.
Biggins said they explored this possibility partly because of earlier findings by a Cornell researcher, Andy Ruina, on a different, but related, problem in falling-chain physics.
Finding a new physics problem in an Internet video was, Biggins said, something of a treat. For a scientist, it’s “reassuring” that new problems like this can pop up, he said.
He and Warner published their paper on Jan. 15 in the Proceedings of the Royal Society A. And the chain fountain is now, as Warner hoped, part of a physics course for high school students.
As for Mould, he is touring at the moment as part of a science comedy show called “Festival of the Spoken Nerd,” in which he talks about the chain fountain.
One of the most enjoyable performances, he said, was in Cambridge last month, because Biggins and Warner, who had talked to him about their research, attended the show.
“They were in the audience,” he said, “with the whole physics department.” | <urn:uuid:2c6ab2cc-aba4-4f45-ac83-2ecce4605e0f> | CC-MAIN-2016-26 | http://www.buffalonews.com/new-york-times/video-of-chain-fountain-excites-scientists-20140303 | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783396147.66/warc/CC-MAIN-20160624154956-00172-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.97393 | 811 | 3.09375 | 3 |
A logical, step-by-step process, from data collection to detailed engineering
A typical university campus can have as many as several hundred buildings. While these buildings may vary greatly in terms of type and utilization, they all need thermal energy for space heating, humidification, domestic-water heating, and the like. With most university-campus buildings in close proximity to each other, district steam systems are a viable thermal-energy source, as confirmed by the hundreds of universities across North America that utilize them.
A district steam system consists of at least one steam boiler, a fuel system, a feedwater system, a flue-emissions-control system, a boiler-control system, a condensate-return system, and a steam-distribution system. This article will discuss steam-distribution-system design outside of a boiler plant, focusing on data collection, preliminary engineering, and detailed engineering. A university replacing building- dedicated steam boilers with a campuswide district steam system will be used as an example.
The long-term success of a district steam system is dependant upon the gathering of all relevant site physical data (site survey, soils report, environmental testing, current steam usage) and owner requirements (future steam usage, steam requirements).
Site survey. For a district steam system, hiring a state-licensed land surveyor to develop survey drawings is essential. These drawings must include:
- Topography profiles, with contours every 2 ft of elevation, for the entire steam path.
- Building locations, with main- and basement-floor elevations.
- All roads and walkways.
- All road and utility easements.
- All underground utilities (water, sewer, electrical, teledata, steam, etc.). The surveyor's contract should include pot holing so that exact utility inverts can be determined.
- All underground man-made obstructions (culverts, tunnels, mines).
- All power/telephone poles, street lights, signs, and monuments.
- Grave sites.
- Historical and archaeologically significant sites. * Trees and shrubs.
- Underground springs or streams.
Soils report. In plotting a steam-distribution-piping path, a good understanding of subsurface soil conditions (rock, silt, sand, previously disturbed earth, water level) is vitally important. With a couple thousand of extra dollars spent on soil borings--and the subsequent moving of a planned steam-distribution path by 30 or 40 ft or the raising of buried steam-distribution piping by a foot--the expense of several hundred thousand dollars on the blasting of rock, the replacement of bad fill material, or construction dewatering can be avoided.
In addition to information on subsoil conditions, a soils report should provide information on soil compressive strength.
Environmental testing. Most mechanical-engineering firms do not perform environmental testing, their liability insurance not covering environmental claims. Therefore, universities are encouraged to hire an independent environmental consulting firm for all environmental testing and remediation-plan development. Designers should discuss with these firms a campus' history. Does a proposed steam-distribution path go through an area from which a chemistry building or boiler fuel-oil tank was removed? Does the soil need to be tested for contaminants? Does existing steam piping have asbestos insulation or fittings?
Current steam usage. Utilize available steam-flow data. If individual-building steam-flow data is not available, install temporary flow sensors. If temporary flow sensors are impractical, the university's facility department may have steam-flow values it wants used, or it might be necessary to perform heating-load calculations to determine each building's maximum steam-flow requirement.
Future steam usage. Most universities have a 10-, 20-, or 30-year strategic capital plan noting the location, size, and utilization of future facilities. Based on existing-building steam usage, determine future-building steam usage on a square-foot basis. Beyond that, determine with the university the excess steam capacity. (Typically, excess steam capacity is in the 10-to-30-percent range.) Once all steam usage is determined, develop a table with building name, maximum steam usage (pounds per hour), and required steam pressure (Table 1). Note any maximum steam usage that does not occur during normal high-steam-usage months (December, January, and February). Do this on a monthly or quarterly basis.
As can be seen in Table 1, maximum steam usage on our example campus is 258,500 lb per hour.
Steam requirements. What is the required steam pressure for each building? What boiler chemicals and feedwater-treatment system are being used? What is the required system reliability and maintainability? What is the quality of the steam? What metering is required?
The steam-distribution-system design criteria for our example campus included the ability to shut down a portion of the system for expansion or maintenance without interrupting steam service, minimal system maintenance, and project completion within a restricted capital budget.
Pipe routing. The most reliable pipe routing proved to be a loop configuration around the campus (Figure 1). The design engineer wanted to route the steam main just west of buildings 301 and 303; however, an ancient Indian burial site was discovered in the proposed steam-main path. The steam main then was rerouted farther west, through dormitories.
Steam pressure. According to Table 1, 100-psig pressure is required for 40 percent of the steam load, 50-psig pressure is required for 5 percent, and 15-psig pressure is required for the remaining 55 percent. One possible solution was to provide two steam-distribution systems: one at 125-psig pressure and one at 75-psig pressure. Because of restricted funding, a single 125-psig system was chosen. The higher distribution pressure was seen as a way to reduce steam-main pipe size.
Burial method. Steam piping can be buried three ways:
- In a crawl tunnel.
- In a walking tunnel.
Although it is the most economical option, directly buried piping is inaccessible for inspection and maintenance, except at valve pits. A crawl tunnel allows restricted access, while a walking tunnel, which is the most expensive option, allows full access.
District-steam-system piping on our example campus is being buried directly (Photo A).
Although they may look relatively simple, district steam systems are complex, requiring a substantial amount of engineering effort.
Pipe-material selection. District steam and condensate piping typically is made of seamless carbon steel meeting ASTM A53/A53M-07, Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless, or ASTM A106/A106M-06a, Standard Specification for Seamless Carbon Steel Pipe for High-Temperature Service (Grade A or B). These standards establish chemical-composition, manufacturing-process, tensile-stress, and yield-stress requirements for piping. (For more information on these standards, see the sidebar below.) Design, fabrication, and installation should follow ASME (American Society of Mechanical Engineers) B31.1, Power Piping, which has a more stringent fabrication and maximum-allowable-stress requirement than ASME B31.3, Process Piping, and ASME B31.9, Building Services Piping.
Directly buried steam piping can be either:
- Prefabricated and preinsulated. A basic prefabricated piping system has a steam-service pipe, insulation (most often, mineral wood or cellular glass), an air gap, a conduit pipe, and an outer protective coating (fiber-reinforced plastic or coal tar). Enhanced prefabricated piping systems include larger air gaps between the service-pipe insulation and conduit pipe and feature polyurethane insulation on the exterior of the conduit pipe (Photo B). When steam enters the service pipe, the service pipe expands, while the conduit pipe does not. With underground installations, it is important that the conduit pipe handle maximum service-pipe expansion. Prefabricated piping is produced in many different lengths, with 20 ft and 40 ft the most economical.
- Encased in poured calcium carbonate. This method involves the installation of steam piping, the installation of form work around the piping, and the pouring of calcium carbonate to a prescribed depth around the piping. The steam piping expands and contracts within the calcium carbonate. Serious consideration should be given to providing a sacrificial-anode or rectifier cathodic-protection system for steam piping.
Most directly buried steam piping is prefabricated and preinsulated.
Crawl- and walking-tunnel-installed steam piping can be prefabricated or field-fabricated. Typically, it is carbon-steel piping with field-applied fiber-glass, cellular-glass, or calcium-silicate insulation and an aluminum outer jacket. Although prefabricated piping costs more than field-fabricated piping, it can be installed in a shorter period of time.
Steam-pipe design. Steam-pipe design includes:
- Steam-pipe sizing. Steam pipes are sized according to steam velocity and steam pressure drop. District steam velocities typically are in the 6,000-to-10,000-fpm range. The allowable total steam-pressure drop within a steam main is based on the difference between the initial supply pressure and the minimum allowable user pressure. In long distribution systems, steam-pressure drops around 10 to 20 percent of initial supply pressure are not unusual. On our example campus, the maximum allowable steam velocity is 8,000 fpm during normal operation and 10,000 fpm with a segment shut down. This requires 18-in. Schedule 40 pipe with a steam-pressure drop of 0.4 psig per 100 ft. The longest system run (2,325 ft) occurs when segment VP-15 to VP-1 (Figure 1) is shut down and results in a 9.3-psig, or 7.4-percent, steam-pressure drop. The 18-in. Schedule 40 pipe has a steam velocity of 8,900 fpm, which is below the owner's maximum-allowable standard, while the lowest steam-main pressure of 116 psig is above the minimum requirement of 100 psig.
- Steam-pipe slope. If condensate is allowed to pool at the bottom of a pipe, a condensate slug can be picked up and hurled down the pipe, causing water hammer and, possibly, catastrophic pipe failure. Condensate can be moved to a steam trap by sloping a steam pipe in the direction of flow. Sloping district steam piping is challenging because of the elevation changes that occur throughout a distribution system. Providing a constant steam-pipe slope from the beginning to the end of a distribution system is not practical. The district steam-distribution system on our example campus would drop more than 23 ft if a constant 1-percent slope were maintained. One sloping method is to saw-tooth steam pipe from valve pit to valve pit (Figure 2). Our example system would have a maximum 3.5-ft elevation drop from valve pit to valve pit if a 1-percent pipe slope were maintained.
Sloping steam pipe in a district steam system is not always possible. Steep topographic elevation changes can have steam pipe sloping sharply up a hill. In such cases, extra attention needs to be paid to steam-trap location. In a looped system, in which steam can flow in either direction, which way should pipe slope?
Automatic air vents at steam-piping high points are important to removing air and carbon dioxide from pipe during system warm-up.
- Steam-pipe condensate removal. Thermodynamic and inverted-bucket steam traps typically are used on steam mains. With crawl and walking tunnels, steam traps can be placed every 100 to 200 ft. With buried steam mains, steam traps can be placed up to 300 ft apart. Placing steam traps in valve pits reduces the number of dedicated steam-trap manholes.
- Steam-pipe-expansion compensation. The two types of district-steam-pipe-expansion compensation are expansion loops and mechanical joints. Expansion loops utilize the spring characteristics of carbon pipe. Configurations include 90-degree elbows, 90-degree "Z" elbows, and loops (Figure 3). Mechanical joints include externally pressurized bellows (Photo C), slip joints (Photo D), and flexible ball joints (Photo E).
For crawl- and walking-tunnel-located piping, mechanical joints are utilized because of their relatively small size and ability to absorb significant pipe expansion in the axial direction. Expansion loops would be difficult to use in tunnels because of space constraints. For directly buried piping, the primary form of expansion compensation is the expansion loop.
Prefabricated, preinsulated, double-wall piping must be designed for the carrier pipe to expand within the conduit pipe. Where there is a straight run from a pipe anchor to a valve pit or steam-trap manhole, a mechanical expansion joint could be installed in the valve pit or steam-trap manhole to absorb carrier-pipe expansion.
Steam-pipe expansion should be designed for the maximum pressure a steam pipe will experience during a system failure. On our example campus, the boilers serving the steam system have two pressure-relief valves set at 175 psig. Steam-pipe expansion is 2.676 in. per 100 ft of pipe length. The maximum distance between anchors is 225 ft, resulting in total pipe expansion of 6.0 in.
Mechanical expansion joints with expansion-compression capacities of 4 to 12 in. are available. When designing a steam-pipe anchor using mechanical-joint expansion compensation, try not to anchor at elbows. Take advantage of the natural expansion capacity of elbows, or use ball joints at elbows.
- Steam-pipe supports and anchors. Steam piping typically experiences maximum pipe-support and anchor forces during hydrostatic tests. The steam system on our example campus needs to be hydrostatically tested to 150 percent of the design steam pressure. During this test, the steam pipe is full of water. As a result, the pipe needs to be supported every 28 ft instead of every 37 ft.
Steam-pipe forces can be substantial. For loop expansion joints and mechanical expansion joints, pipe-anchor forces typically are in the 5,000-to-15,000-lb-force range and 15,000-to-55,000-lb-force range, respectively.
- Steam-pipe isolation valves. Steam valves should provide adequate isolation of district-steam-system sections for routine maintenance, emergency repairs, and system expansion. In our example district steam system, isolation valves are installed at every valve pit--on building branch pipe and either side of tees--to isolate the main between valve pits, as shown in Figure 4.
Valve-pit/manhole design. Valve pits/manholes need to be big enough for piping, expansion joints, isolation valves, pipe anchors, condensate pumps, and sump pits with sump pumps. For maintenance-staff members to be able to access both sides of a pipe, a second access ladder/manhole may be needed. A 10-ft-wide-by-20-ft-long valve pit is not unusual.
A valve pit/manhole should be able to withstand HS-20 highway loads and should not be used to anchor steam and condensate piping. All annular spaces around pipe penetrations need to be sealed with a mechanical sealing mechanism to keep water from leaking into the valve pit.
There should be two ventilation pipes, with one terminating a foot above the floor and the other terminating a foot below the ceiling/lid. These pipes need to be at least 18 in. above grade (adjust height for local snow conditions) and terminated with a bird-screen-covered gooseneck.
Tunnel design. A dedicated district steam tunnel is desirable; however, tunnels often are used for other utilities (electrical, teledata, domestic water, chilled water, etc.). The number and size of the utilities installed will affect the overall size of a tunnel. Tunnels should include a 24-in.-wide maintenance-access aisle. Wall-mounted tunnel lighting should be used to prevent maintenance-staff members from hitting their heads on light fixtures. Tunnels also should include material-installation/removal hatches, drainage, and space for piping expansion.
Tunnels should be able to withstand HS-20 highway loads and reinforced in areas handling steam-pipe-anchor loads. It is important that a tunnel meet this structural requirement in its entirety, not just under roads. Tunnels should be made of field-formed concrete or prefabricated concrete sections.
Hire a professional waterproofing contractor to waterproof the top and sides of your tunnel. Pay extra for premium waterproofing materials, as their performance will be the most significant factor determining your tunnel's useful life.
Tunnel ventilation design. Providing a small amount of ventilation in a tunnel helps remove moisture and heat generated by steam and condensate piping and provides better working conditions for maintenance-staff members. A base 0.10-cfm-per-square-foot ventilation rate will help remove heat and moisture from a tunnel. If the 2,325-ft-long district steam system on our example campus were installed in a 5-ft-wide tunnel, it would require 1,165 cfm of ventilation. To prevent positive pressurization, exhaust fans with intake louvers are used to ventilate the tunnel.
A well-engineered and constructed district steam system can provide safe, reliable, and efficient steam service, while a poorly engineered and/or constructed one can be expensive to operate and maintain, fail frequently, and, possibly, cause a fatality. This article's intent was to provide a logical step-by-step process for engineering a district steam system and to highlight the different components that need to be evaluated. Sidebar: ASTM Piping Standards
ASTM A53/A53M-07, Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless. The two grades of A53 steel pipe are A and B. The primary difference is the percentage of carbon and manganese, which affects tensile and yield strength. The three types of A53 steel pipe are E (electric-resistance-welded), F (furnace butt-welded), and S (seamless).ASTM A106/A106M-06a, Standard Specification for Seamless Carbon Steel Pipe for High-Temperature Service. The three grades of A106 steel pipe are A, B, and C. The primary difference is the percentage of carbon and manganese, which affects tensile and yield strength.
A senior mechanical engineer with Merrick & Co., Vincent A. Sakraida, PE, LEED AP, has 25 years of experience designing mechanical systems for high-technology facilities, as well as extensive experience designing central-plant, laboratory-utility, and HVAC systems. | <urn:uuid:3dbbeac0-0598-4b1a-a9d5-9a22784a3bd9> | CC-MAIN-2016-26 | http://hpac.com/heating/district_steam_design?quicktabs_11=0 | s3://commoncrawl/crawl-data/CC-MAIN-2016-26/segments/1466783396455.95/warc/CC-MAIN-20160624154956-00130-ip-10-164-35-72.ec2.internal.warc.gz | en | 0.908024 | 3,984 | 3.296875 | 3 |
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