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Left atrial wall thickness and outcomes of catheter ablation for atrial fibrillation in patients with hypertrophic cardiomyopathy | Catheter ablation of atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy (HCM) is still challenging, and it is unclear whether the difficulty is caused by the hypertrophy of left atrial (LA) myocardial wall thickness. The objective of the study was to compare the LA wall thickness and AF ablation outcomes between patients with HCM and those without structural heart disease. The present study enrolled 17 consecutive HCM patients (63 ± 12 years) with drug-refractory AF and 34 control patients without any detectable heart disease, whose age, gender, type of AF, and LA dimension were matched to the HCM patients. The myocardial wall thickness of 11 distinct LA locations, measured using 64-slice computed tomography images, and AF ablation outcomes were compared between the two groups. The LA wall thickness did not differ at 9 of the 11 locations and was significantly thinner in the HCM patients than in the control patients at the mid-posterior wall (1.44 ± 0.17 vs. 1.58 ± 0.22, p = 0.04) and infero-posterior wall (1.62 ± 0.16 vs. 1.74 ± 0.18, p = 0.03). Although antiarrhythmic drugs were used more frequently in the HCM patients (p = 0.008), the rate of maintaining sinus rhythm during the follow-up did not differ between the HCM and control patients (53 vs. 56 % after the initial ablation [log-rank p = 0.78] and 82 and 88 % after the repeat procedure [log-rank p = 0.35]). The LA wall in the HCM patients with AF was not thicker than that of the matched patients without structural heart disease. Catheter ablation of AF showed favorable outcomes in both patient groups. |
KB-LDA: Jointly Learning a Knowledge Base of Hierarchy, Relations, and Facts | Many existing knowledge bases (KBs), including Freebase, Yago, and NELL, rely on a fixed ontology, given as an input to the system, which defines the data to be cataloged in the KB, i.e., a hierarchy of categories and relations between them. The system then extracts facts that match the predefined ontology. We propose an unsupervised model that jointly learns a latent ontological structure of an input corpus, and identifies facts from the corpus that match the learned structure. Our approach combines mixed membership stochastic block models and topic models to infer a structure by jointly modeling text, a latent concept hierarchy, and latent semantic relationships among the entities mentioned in the text. As a case study, we apply the model to a corpus of Web documents from the software domain, and evaluate the accuracy of the various components of the learned ontology. |
Three tensions in participatory design for inclusion | One ideal of Participatory Design (PD) is active involvement by all stakeholders as co-designers. However, when PD is applied to real projects, certain compromises are unavoidable, no matter what stakeholders are involved. With this paper we want to shed light on some of the challenges in implementing "true" PD in the case of designing with children, in particular children with severe disabilities. We do this work to better understand challenges in an ongoing project, RHYME, and by doing so we hope to provide insight and inspiration for others. |
Group Nonnegative Matrix Factorization for EEG Classification | Given electroencephalogram (EEG) data measured from several subjects under the same conditions, our goal is to estimate common task-related bases in a linear model that capture intra-subject variations as well as inter-subject variations. Such bases capture the common phenomenon in group data, which is a core of group analysis. In this paper we present a method of nonnegative matrix factorization (NMF) that is well suited to analyzing EEG data of multiple subjects. The method is referred to as group nonnegative matrix factorization (GNMF) where we seek task-related common bases reflecting both intra-subject and inter-subject variations, as well as bases involving individual characteristics. We compare GNMF with NMF and some modified NMFs, in the task of learning spectral features from EEG data. Experiments on brain computer interface (BCI) competition data indicate that GNMF improves the EEG classification performance. In addition, we also show that GNMF is useful in the task of subject-tosubject transfer where the prediction for an unseen subject is performed based on a linear model learned from different subjects in the same group. |
Examination of blood–brain barrier (BBB) integrity in a mouse brain tumor model | The present study evaluates, both functionally and biochemically, brain tumor-induced alterations in brain capillary endothelial cells. Brain tumors were induced in Balb/c mice via intracranial injection of Lewis Lung carcinoma cells into the right hemisphere of the mouse brain using stereotaxic apparatus. Blood–brain barrier (BBB) permeability was assessed at various stages of tumor development, using both radiolabeled tracer permeability and magnetic resonance imaging with gadolinium diethylene-triamine-pentaacetate contrast enhancement (Gad-DTPA). The expression of the drug efflux transporter, P-glycoprotein (P-gp), in the BBB at various stages of tumor development was also evaluated by Western blot and immunohistochemistry. Median mouse survival following tumor cell injection was 17 days. The permeability of the BBB to 3H-mannitol was similar in both brain hemispheres at 7 and 10 days post-injection. By day 15, there was a twofold increase in 3H-mannitol permeability in the tumor bearing hemispheres compared to the non-tumor hemispheres. Examination of BBB permeability with Gad-DTPA contrast enhanced MRI indicated cerebral vascular permeability changes were confined to the tumor area. The permeability increase observed at the later stages of tumor development correlated with an increase in cerebral vascular volume suggesting angiogenesis within the tumor bearing hemisphere. Furthermore, the Gad-DPTA enhancement observed within the tumor area was significantly less than Gad-DPTA enhancement within the circumventricular organs not protected by the BBB. Expression of P-gp in both the tumor bearing and non-tumor bearing portions of the brain appeared similar at all time points examined. These studies suggest that although BBB integrity is altered within the tumor site at later stages of development, the BBB is still functional and limiting in terms of solute and drug permeability in and around the tumor. |
Aqueous dye-sensitized solar cells. | Nowadays, dye-sensitized solar cells (DSSCs) are the most extensively investigated systems for the conversion of solar energy into electricity, particularly for implementation in devices where low cost and good performance are required. Nevertheless, a key aspect is still to be addressed, being considered strongly harmful for a long time, which is the presence of water in the cell, either in the electrolyte or at the electrode/electrolyte interface. Here comes the present review, in the course of which we try our best to address the highly topical role of water in DSSCs, trying to figure out if it is a poisoner or the keyword to success, by means of a thoroughly detailed analysis of all the established phenomena in an aqueous environment. Actually, in the last few years the scientific community has suddenly turned its efforts in the direction of using water as a solvent, as demonstrated by the amount of research articles being published in the literature. Indeed, by means of DSSCs fabricated with water-based electrolytes, reduced costs, non-flammability, reduced volatility and improved environmental compatibility could be easily achieved. As a result, an increasing number of novel electrodes, dyes and electrolyte components are continuously proposed, being highly challenging from the materials science viewpoint and with the golden thread of producing truly water-based DSSCs. If the initial purpose of DSSCs was the construction of an artificial photosynthetic system able to convert solar light into electricity, the use of water as the key component may represent a great step forward towards their widespread diffusion in the market. |
Effective and safe but forgotten: methsuximide in intractable epilepsies in childhood | The efficacy and safety of methsuximide (MSM) was evaluated in children with intractable epilepsies in a prospective uncontrolled study. MSM was added to the therapeutic regimen of 112 children with intractable epilepsy under inpatient conditions, all of whom were therapeutically refractory to various first-line antiepileptic drugs (AED) or combinations of other AED. Titration of MSM was performed following a uniform protocol. Administration of MSM resulted in a 50% or greater reduction in seizure frequency in 40 patients after a short-term observation period (mean 9.1 weeks). After a mean of 3.7 years, the rate of seizures and side effects were re-evaluated in 39 patients who were still receiving MSM as part of their antiepileptic regimen. Twenty two of these patients derived long-term benefit from MSM. In patients with good seizure control, fasting plasma levels of N-desmethylmethsuximide, the principal active metabolite of MSM, were 25.3-44.7 mg l(-1)(mean 36.0 mg l(-1)). Thus effective plasma levels of N-desmethylmethsuximide in children were found to be higher than previously described. Forty one of 112 patients (28.9%) developed side effects during MSM treatment. No serious or irreversible side effects were seen. Our study demonstrates the value of MSM as an 'add-on' drug in intractable epilepsies. |
Novel recurrently mutated genes in African American colon cancers. | We used whole-exome and targeted sequencing to characterize somatic mutations in 103 colorectal cancers (CRC) from African Americans, identifying 20 new genes as significantly mutated in CRC. Resequencing 129 Caucasian derived CRCs confirmed a 15-gene set as a preferential target for mutations in African American CRCs. Two predominant genes, ephrin type A receptor 6 (EPHA6) and folliculin (FLCN), with mutations exclusive to African American CRCs, are by genetic and biological criteria highly likely African American CRC driver genes. These previously unsuspected differences in the mutational landscapes of CRCs arising among individuals of different ethnicities have potential to impact on broader disparities in cancer behaviors. |
Inverted Sine Carrier for Fundamental Fortification in PWM Inverters and FPGA Based Implementations | Abstract: This paper deals with a novel natural sampled pulse width modulation (PWM) switching strategy for voltage source inverter through carrier modification. The proposed inverted sine carrier PWM (ISCPWM) method, which uses the conventional sinusoidal reference signal and an inverted sine carrier, has a better spectral quality and a higher fundamental component compared to the conventional sinusoidal PWM (SPWM) without any pulse dropping. The ISCPWM strategy enhances the fundamental output voltage particularly at lower modulation index ranges while keeping the total harmonic distortion (THD) lower without involving changes in device switching losses. The presented mathematical preliminaries for both SPWM and ISCPWM give a conceptual understanding and a comparison of the strategies. The detailed comparison of the harmonic content and fundamental component of the ISCPWM output for different values of modulation index with the results obtained for the SPWM is also presented. Finally, the proposed modulator has been implemented in field programmable gate array (FPGAXilinx Spartan 3) and tested with the proto-type inverter. |
Adapting RFID Technology for Implementation of a New Birth Record in Jordanian Hospitals | This paper introduces a new integrated clinical record in Jordan using the RFID technology, where currently no clinical report links antenatal, birth and postnatal care for women. As a result no continuity of information is provided to clinicians nor are there national statistics on trends, or performance of hospitals around birth. The paper is based on a study conducted in the Jordanian Ministry of Health, the maternity wards and registration departments of three hospitals in Jordan and in the Maternal Child Health Centers located near these hospitals [1]. Lack of active follow-up to ensure the best service for antenatal, birth and postnatal care for women is the main problem. An RFID model for managing the clinical record for maternal child was proposed. The model is valuable to policy makers and program implementers in strengthening implementation of programs and activities to improve maternal child care services. The statistics yielded from the proposed RFID model is of particular importance to help fulfill this need. The proposed maternal child management system is expected to control the health care cost, improve the care quality, and provide a comprehensive strategy for restructuring maternal child care delivery system. |
Differential effects of stress and glucocorticoids on adult neurogenesis. | Stress is known to inhibit neuronal growth in the hippocampus. In addition to reducing the size and complexity of the dendritic tree, stress and elevated glucocorticoid levels are known to inhibit adult neurogenesis. Despite the negative effects of stress hormones on progenitor cell proliferation in the hippocampus, some experiences which produce robust increases in glucocorticoid levels actually promote neuronal growth. These experiences, including running, mating, enriched environment living, and intracranial self-stimulation, all share in common a strong hedonic component. Taken together, the findings suggest that rewarding experiences buffer progenitor cells in the dentate gyrus from the negative effects of elevated stress hormones. This chapter considers the evidence that stress and glucocorticoids inhibit neuronal growth along with the paradoxical findings of enhanced neuronal growth under rewarding conditions with a view toward understanding the underlying biological mechanisms. |
Commercial Visual Analytics Systems-Advances in the Big Data Analytics Field. | Five years after the first state-of-the-art report on Commercial Visual Analytics Systems we present a reevaluation of the Big Data Analytics field. We build on the success of the 2012 survey, which was influential even beyond the boundaries of the InfoVis and Visual Analytics (VA) community. While the field has matured significantly since the original survey, we find that innovation and research-driven development are increasingly sacrificed to satisfy a wide range of user groups. We evaluate new product versions on established evaluation criteria, such as available features, performance, and usability, to extend on and assure comparability with the previous survey. We also investigate previously unavailable products to paint a more complete picture of the commercial VA landscape. Furthermore, we introduce novel measures, like suitability for specific user groups and the ability to handle complex data types, and undertake a new case study to highlight innovative features. We explore the achievements in the commercial sector in addressing VA challenges and propose novel developments that should be on systems' roadmaps in the coming years. |
Recommended Best Industrial Practice for Software Architecture Evaluation. | Architectural decisions have a great impact on the consequent quality of software systems. As a result, it is important to evaluate how a software architecture meets its quality demands. Though much focus has been placed on modeling and describing the software architecture as a design artifact, we found that relatively little is known about the current experience with software architecture evaluation. This report details the results of two workshops on software architecture evaluation, held at the Software Engineering Institute (SEI) on November 9-10, 1995 and May 9-10, 1996. The purpose of the workshops was to determine the state of industrial practice in the evaluation of software architectures with respect to a set of desired quality attributes, and to uncover recommendations for best practices. In this report, we summarize the findings of the two workshops, define a set of dimensions to characterize various software architecture evaluation techniques, and make concrete recommendations for implementing architecture evaluation practices. |
The assessment of constipation in monosymptomatic primary nocturnal enuresis | Objective: Nocturnal enuresis and constipation are common pediatric problems. The aim of this study was to assess the incidence of constipation in children with or without monosymptomatic primary nocturnal enuresis.Methods: The study included 5350 children, ages 5–19 years, who were surveyed to detect the incidence of nocturnal enuresis. Of those surveyed, 679 (12.7%) had primary nocturnal enuresis. All children were questioned by mail with a standard form that addressed their micturition and defecation habits. The children those who had primary nocturnal enuresis were invited to the Pediatric Urology Section of the University Hospital. Of those 679 children, 125 kept that invitation. All 125 of those children underwent an abdominal ultrasound. Also, these children had serum creatinine levels drawn and plain abdominal films taken.Results: Constipation, defined as less than 3 bowel movements per week, was seen in 48 of 679 children with nocturnal enuresis (7.06%). Of those 4671 children without nocturnal enuresis, only 68 (1.45%) had constipation. The difference in constipation between the two groups was statistically significant (z = −9.251; p = 0.000). Of note, 10 of the 125 children (8%), evaluated at the hospital, had constipation. None of the children had an abnormal neurologic examination. Finally, faecal loading was detected on the plain films of 8 of the 125 children evaluated, 7 of who had constipation. The sensitivity of grading plain films for faecal loading to denote constipation in this population was 87.5%.Conclusions: Children with primary nocturnal enuresis should be thoroughly assessed for coexisting constipation. |
A new ZVS bidirectional DC-DC converter for fuel cell and battery application | This paper presents a new zero-voltage-switching (ZVS) bidirectional dc-dc converter. Compared to the traditional full and half bridge bidirectional dc-dc converters for the similar applications, the new topology has the advantages of simple circuit topology with no total device rating (TDR) penalty, soft-switching implementation without additional devices, high efficiency and simple control. These advantages make the new converter promising for medium and high power applications especially for auxiliary power supply in fuel cell vehicles and power generation where the high power density, low cost, lightweight and high reliability power converters are required. The operating principle, theoretical analysis, and design guidelines are provided in this paper. The simulation and the experimental verifications are also presented. |
A randomized, double-blind, placebo-controlled trial and open-label extension study to evaluate the efficacy and safety of pregabalin in the treatment of neuropathic pain associated with human immunodeficiency virus neuropathy | The objective of these studies was to assess the efficacy and safety of pregabalin in the treatment of human immunodeficiency virus (HIV)-associated neuropathic pain. Patients with HIV-associated distal sensory polyneuropathy (DSP) were randomized to treatment with flexible-dose pregabalin (150-600 mg/day) or placebo for 17 weeks in a single-blind, placebo lead-in, randomized, double-blind, parallel-group, placebo-controlled multinational trial. The primary efficacy outcome was the change in mean pain score on an 11-point numeric rating scale (NRS) from baseline to study endpoint. Participants who completed this trial were invited to participate in a 6-month open-label extension study with pregabalin. Of the 377 patients enrolled in the randomized controlled trial (pregabalin, n=183; placebo, n=194), 68.4% completed treatment. In the open-label extension, 217 patients were treated and 59.4% completed treatment. Both studies were terminated by the sponsor after a preplanned interim analysis indicated trial futility. At endpoint, the change from baseline in least-squares mean NRS pain scores in the intent-to-treat population was -2.04 for pregabalin versus -2.11 for placebo (P=.709). There were no significant differences between the pregabalin and placebo groups in the secondary efficacy measures. Incidence of adverse events was lower than seen in previous pregabalin studies. Overall, this trial did not show pregabalin to be more efficacious than placebo in treating HIV-associated DSP. Studies such as these, which fail to support their primary hypotheses, may be important in informing the methodology of future trials, especially when novel approaches to limit variability in the control group are included. ClinicalTrials.gov identifiers: NCT01049217 and NCT01145417. |
Focusing of magma in the upper mantle through dike interaction: DIKE INTERACTION AND MAGMA FOCUSING | [1] We use laboratory experiments and numerical models to quantify the effects of dike interaction on the focusing of magma as it ascends in the upper mantle. Laboratory experiments involve injecting buoyant fluid into the base of a tank filled with solidified gelatin. When we initiate two dikes parallel to each other, but separated by a horizontal distance x, they tend to merge as they ascend. This behavior is also predicted by numerical models of two-dimensional dikes. The key parameters that control the maximum horizontal separation xc over which dikes will intersect are dike driving pressures, dike head lengths L (i.e., the length over which driving pressure is large), and the difference between the principal stresses of the remote stress field. When the remote differential stress is small compared to the dike driving pressure, two dikes of equal driving pressure and length will intersect over distances of xc ∼ L. This distance decreases with increasing remote differential stress. We quantify the effects on magma transport from a broad lateral distribution of magma using numerical simulations of multiple-dike interaction. When the average dike spacing prior to interaction is within ∼3L and remote differential stresses are insignificant, dike interaction can focus magma over horizontal distances many times L but at least ∼6L. Dike interaction can focus magma in the asthenosphere beneath mid-ocean ridges for low mantle viscosities (≤1019 Pa s) and if dikes initiate with average separations of a few hundred meters, or less. Such focusing is predicted to grow dikes of increasing magma flux approaching lateral separations of a kilometer. |
On Memory Reuse Between Inputs and Outputs of Dataflow Actors | This article introduces a new technique to minimize the memory footprints of Digital Signal Processing (DSP) applications specified with Synchronous Dataflow (SDF) graphs and implemented on shared-memory Multiprocessor System-on-Chip (MPSoCs). In addition to the SDF specification, which captures data dependencies between coarse-grained tasks called actors, the proposed technique relies on two optional inputs abstracting the internal data dependencies of actors: annotations of the ports of actors, and script-based specifications of merging opportunities between input and output buffers of actors. Experimental results on a set of applications show a reduction of the memory footprint by 48% compared to state-of-the-art minimization techniques. |
Cannabis for Pain and Headaches: Primer. | PURPOSE OF REVIEW
Marijuana has been used both medicinally and recreationally since ancient times and interest in its compounds for pain relief has increased in recent years. The identification of our own intrinsic, endocannabinoid system has laid the foundation for further research.
RECENT FINDINGS
Synthetic cannabinoids are being developed and synthesized from the marijuana plant such as dronabinol and nabilone. The US Food and Drug Administration approved the use of dronabinol and nabilone for chemotherapy-associated nausea and vomiting and HIV (Human Immunodeficiency Virus) wasting. Nabiximols is a cannabis extract that is approved for the treatment of spasticity and intractable pain in Canada and the UK. Further clinical trials are studying the effect of marijuana extracts for seizure disorders. Phytocannabinoids have been identified as key compounds involved in analgesia and anti-inflammatory effects. Other compounds found in cannabis such as flavonoids and terpenes are also being investigated as to their individual or synergistic effects. This article will review relevant literature regarding medical use of marijuana and cannabinoid pharmaceuticals with an emphasis on pain and headaches. |
The Political Economy of the Peace Process in a Changing Middle East | UNU World Institute for Development Economics Research (UNU/WIDER) was established by the United Nations University as its first research and training centre and started work in Helsinki, Finland, in 1985. The principal purpose of the Institute is policy-oriented research on the main strategic issues of development and international cooperation, as well as on the interaction between domestic and global changes. Its work is carried out by staff researchers and visiting scholars in Helsinki and through networks of collaborating institutions and scholars around the world. The views expressed in this publication are those of the author(s). Publication does not imply endorsement by the Institute or the United Nations University of any of the views expressed. 1.1 Introduction 1 1.2 A historical overview 3 1.3 Regionalism and disintegration; ideology and politics of the last 50 years 9 1.4 The peace process in the Middle East 16 II REGIONAL DEVELOPMENT COOPERATION: THE INFLUENCE OF PEACE 29 2.1 The hopes, realities and prospects of economic cooperation-integration 29 2.2 Israel, its modern economy, and the Palestinians 31 2.3 Cooperation and Palestinian self-rule (self-government) arrangements 33 2.4 A peace dividend for the region 44 III WATER-THE CRITICAL ECO-POLITICAL ISSUE 49 3.1 Water-a key for the future 49 3.2 The international nature of Middle East water 50 3.3 Water resources of Israel, the West Bank, and the Gaza Strip 54 3.4 Jordan's water resources 59 IV INSTEAD OF A CONCLUSION 63 4.1 Efforts made-efforts needed 63 4.2 The role and response of the UN, international and regional organizations to the changing Middle East 66 4.3 Limitations of studies and research 66 BIBLIOGRAPHY 68 iii IV FOREWORD The character and consequences of the interconnectedness and interaction between international political and economic processes in the post-cold war era has changed in many respects, as compared to the previous decades. During the cold war years, economic factors played of course important roles in shaping the global power structure, and influencing international politics but in many respects, the political agenda of the two global powers dominated the global system. In the post-cold war world, the influence of the economic factors became much stronger in shaping global changes. Capital flows, technology and international entrepreneurship are the key components of the globalization process. The relative economic power of countries, international economic competitiveness and competition has a much greater impact on interstate relations than in the past. The pressure of the domestic socioeconomic problems … |
Modeling biological motor control for human locomotion with functional electrical stimulation | This paper develops a novel control system for functional electrical stimulation (FES) locomotion, which aims to generate normal locomotion for paraplegics via FES. It explores the possibility of applying ideas from biology to engineering. The neural control mechanism of the biological motor system, the central pattern generator, has been adopted in the control system design. Some artificial control techniques such as neural network control, fuzzy logic, control and impedance control are incorporated to refine the control performance. Several types of sensory feedback are integrated to endow this control system with an adaptive ability. A musculoskeletal model with 7 segments and 18 muscles is constructed for the simulation study. Satisfactory simulation results are achieved under this FES control system, which indicates a promising technique for the potential application of FES locomotion in future. |
Surviving or Flourishing ? Integrating Business Resilience and Sustainability | Purpose Businesses are always seeking resilient strategies so they can weather unpredictable competitive environments. One source of unpredictability is the unsustainability of commerce’s environmental, economic or social impacts and the limitations this places on businesses. Another is poor resilience causing erroneous and unexpected outputs. Companies prospering long-term must have both resilience and sustainability, existing in a symbiotic state. This paper explores the two concepts and their relationship, their combined benefits and proposes an approach for supporting decision-makers to proactively build both characteristics. Design/methodology/approach The paper looks at businesses as complex adaptive systems, how their resilience and sustainability can be defined and how these might be exhibited. It then explores how they can be combined in practice. Findings The two qualities are related but have different purposes, moreover resilience has two major forms related to timescales. Both kinds of resilience are identified as key for delivering sustainability, yet the reverse is also found to be true. Both are needed to deliver either and to let businesses flourish. Practical implications Although the ideal state of resilient sustainability is difficult to define or achieve, pragmatic ways exist to deliver the right direction of change in organisational decisions. A novel approach to this is explored based on Transition Engineering and Robustness Engineering. Originality/value This paper links resilience and sustainability explicitly and develops a holistic pragmatic approach for working through their implications in strategic decision-making. |
Mitigating Sybils in Federated Learning Poisoning | Machine learning (ML) over distributed multiparty data is required for a variety of domains. Existing approaches, such as federated learning, collect the outputs computed by a group of devices at a central aggregator and run iterative algorithms to train a globally shared model. Unfortunately, such approaches are susceptible to a variety of attacks, including model poisoning, which is made substantially worse in the presence of sybils. In this paper we first evaluate the vulnerability of federated learning to sybil-based poisoning attacks. We then describe FoolsGold, a novel defense to this problem that identifies poisoning sybils based on the diversity of client updates in the distributed learning process. Unlike prior work, our system does not bound the expected number of attackers, requires no auxiliary information outside of the learning process, and makes fewer assumptions about clients |
Transmitter chipset for 24/77-GHz automotive radar sensors | This paper presents a SiGe BiCMOS transmitter chipset for 24/77-GHz automotive radar sensors. The chipset adopts a dual-band architecture consisting of a 24-GHz section for ultra-wideband short-range radar operation, which is able to drive the 77-GHz long-range radar transmitter front-end. The proposed solution allows using a single 24-GHz frequency synthesizer to implement both operation modes. The 77-GHz transmitter demonstrates an output power of 12 dBm, a power gain of 20 dB and an output-referred 1-dB compression point of 11 dBm, while drawing 155 mA from a 2.5-V supply voltage. |
Lung deposition and systemic availability of fluticasone Diskus and budesonide Turbuhaler in children. | Pharmacokinetic studies can be used to measure lung dose of inhaled drugs. The aim of this study was to compare the lung deposition of budesonide (BUD) inhaled from Turbuhaler (AstraZeneca, Lund, Sweden) and fluticasone propionate (FP) inhaled from Diskus (GlaxoSmithKline, London, UK) and to assess if the study design used for pharmacokinetic studies can be simplified. Plasma levels of BUD and FP were measured for 21 hours on five separate days in 15 patients aged 8 to 14 years: (1) Intravenous infusion of 200 microg BUD, (2) intravenous infusion of 200 microg fluticasone dipropionate, (3) inhalation of 800 microg BUD via Turbuhaler, (4) inhalation of 750 microg FP via Diskus, and (5) inhalation of BUD and FP on the same day. Charcoal was ingested to eliminate drug uptake from the gastrointestinal tract. The mean lung deposition of drug after Turbuhaler and Diskus inhalation was 30.8 and 8.0% when BUD and fluticasone were administered on separate days and 29.5% (BUD) and 7.6% (fluticasone) when the two drugs were inhaled on the same day. Lung deposition is four times higher in children after inhalation from Turbuhaler than after inhalation from Diskus. Pharmacokinetic studies with BUD and FP can be simplified because the two treatments can be administered on the same day. |
PRF-ambiguity resolving by wavelength diversity | For high precision Synthetic Aperture Radar (SAR) processing, the determination of the Doppler centroid is indispensable. The Doppler frequency estimated from azimuth spectra, however, suffers from the fact that the data are sampled with the pulse repetition frequency (PRF) and an ambiguity about the correct PRF band remains. A new algorithm to resolve this ambiguity is proposed. It uses the fact that the Doppler centroid depends linearly on the transmitted radar frequency for a given antenna squint angle. This dependence is not subject to PRF ambiguities. It can be measured by Fourier transforming the SAR data in the range direction and estimating the Doppler centroid at each range frequency. The achievable accuracy is derived theoretically and verified with Seasat data of different scene content. The algorithm works best with low contrast scenes, where the conventional look correlation technique fails. It needs no iterative processing of the SAR data and causes only low computational load. |
jFuzzyLogic: a Java Library to Design Fuzzy Logic Controllers According to the Standard for Fuzzy Control Programming | Fuzzy Logic Controllers are a specific model of Fuzzy Rule Based Systems suitable for engineering applications for which classic control strategies do not achieve good results or for when it is too difficult to obtain a mathematical model. Recently, the International Electrotechnical Commission has published a standard for fuzzy control programming in part 7 of the IEC 61131 norm in order to offer a well defined common understanding of the basic means with which to integrate fuzzy control applications in control systems. In this paper, we introduce an open source Java library called jFuzzyLogic which offers a fully functional and complete implementation of a fuzzy inference system according to this standard, providing a programming interface and Eclipse plugin to easily write and test code for fuzzy control applications. A case study is given to illustrate the use of jFuzzyLogic. |
Survey of Standardized Protocols for the Internet of Things | Internet of Things is a growing technology, developing in multiple fields, from smart homes to health and industries. From a technological perspective, it enables the development of new protocols and scenarios, since the standard network protocol suite cannot face the growing number of connected devices and data transmitted. This paper aims to present several standardized protocols, at different networking levels, developed especially for embedded devices with low memory, low processing power and low data rate. We also propose a smart home scenario that uses only standardized IoT protocols. |
User Modeling in Large Social Networks | This proposal aims to harness the power of data, social, and network sciences to model user behavior in social networks. Specifically, we focus on individual users and investigate the interplay between their behavior and subsequently emergent social phenomena. Work in this proposal unveils the significant social strategies that are used by people to satisfy their social needs. We apply computational methods to address user modeling problems, including demographic inference, link recommendation, and social impact prediction. The proposed research work can be translated into applications in large social systems, such as mobile communication, online social media, and academic collaboration. |
Efficient and effective retrieval using selective pruning | Retrieval can be made more efficient by deploying dynamic pruning strategies such as WAND, which do not degrade effectiveness up to a given rank. It is possible to increase the efficiency of such techniques by pruning more 'aggressively'. However, this may reduce effectiveness. In this work, we propose a novel selective framework that determines the appropriate amount of pruning aggressiveness on a per-query basis, thereby increasing overall efficiency without significantly reducing overall effectiveness. We postulate two hypotheses about the queries that should be pruned more aggressively, which generate two approaches within our framework, based on query performance predictors and query efficiency predictors, respectively. We thoroughly experiment to ascertain the efficiency and effectiveness impacts of the proposed approaches, as part of a search engine deploying state-of-the-art learning to rank techniques. Our results on 50 million documents of the TREC ClueWeb09 collection show that by using query efficiency predictors to target inefficient queries, we observe that a 36% reduction in mean response time and a 50% reduction of the response times experienced by the slowest 10% of queries can be achieved while still ensuring effectiveness. |
The Mechanism and Empirical Test on the Effect of Technological Innovation on International Service Outsourcing in China | Technological innovation can promote the growth of international service outsourcing in China by advancing enterprise ability to undertake international service outsourcing, human resource quality, upgrading of international service outsourcing industry and base building of international service outsourcing. Based on the relative data from 10 areas where the international service outsourcing is developed best in China, this article builds the regression model to study the effect of technological innovation on international service outsourcing. The result indicates that technological innovation can promote obviously the development of international service outsourcing. Some suggestion should be taken to accelerate the technology innovation ability of china, such as adding the input to technological innovation, encouraging talent engaged in the international service outsourcing industry, optimizing environment of technological innovation. |
Perceived organizational support and turnover intention: the mediating effects of personal sacrifice and job fit. | This study examines the mediating role of job fit on the relationship between perceived supervisor support (PSS) and perceived organizational support (POS), and the mediating role of personal sacrifice on the relationship between POS and turnover intention. We use structural equation modeling (SEM) with a data set consisting of a sample of 346 individuals in a manufacturing firm to test our proposed model of PSS, POS, and turnover intention. Consistent with prior literature, our hypothesized model confirms that PSS is a predictor of POS and that POS is a predictor of turnover intention. By testing two additional competing and theoretically derived nested models, our findings indicate that job fit partially mediates the relationship between PSS and POS, and that personal sacrifice partially mediates the relationship between POS and turnover intention. Our study is among the first to examine job fit and personal sacrifice as mediators within the POS-turnover intention model. |
Driver Drowsiness Detection System Based on Feature Representation Learning Using Various Deep Networks | Statistics have shown that 20% of all road accidents are fatigue-related, and drowsy detection is a car safety algorithm that can alert a snoozing driver in hopes of preventing an accident. This paper proposes a deep architecture referred to as deep drowsiness detection (DDD) network for learning effective features and detecting drowsiness given a RGB input video of a driver. The DDD network consists of three deep networks for attaining global robustness to background and environmental variations and learning local facial movements and head gestures important for reliable detection. The outputs of the three networks are integrated and fed to a softmax classifier for drowsiness detection. Experimental results show that DDD achieves 73.06% detection accuracy on NTHU-drowsy driver detection benchmark dataset. |
Anti-neutrophil cytoplasmic (ANCA) and anti-glomerular basement membrane (GBM) autoantibodies in necrotizing and crescentic glomerulonephritis | Anti-neutrophil cytoplasmic autoantibodies (ANCA) and anti-glomerular basement membrane (GBM) necrotizing and crescentic glomerulonephritis are aggressive and destructive glomerular diseases that are associated with and probably caused by circulating ANCA and anti-GBM antibodies. These necrotizing lesions are manifested by acute nephritis and deteriorating kidney function often accompanied by distinctive clinical features of systemic disease. Prompt diagnosis requires clinical acumen that allows for the prompt institution of therapy aimed at removing circulating autoantibodies and quelling the inflammatory process. Continuing exploration of the etiology and pathogenesis of these aggressive inflammatory diseases have gradually uncovered new paradigms for the cause of and more specific therapy for these particular glomerular disorders and for autoimmune glomerular diseases in general. |
The Relation between Elementary Students' Recreational and Academic Reading Motivation, Reading Frequency, Engagement, and Comprehension: A Self-Determination Theory Perspective. | Research indicates the need to further examine the dimensions of reading motivation. A clear theoretical basis is necessary for conceptualizing reading motivation and considering contextual differences therein. The present study develops and validates the SRQ-Reading Motivation, a questionnaire measuring recreational and academic reading motivation based on self-determination theory. The study clarifies the relation among reading motivation, reading self-concept, reading behavior (i.e., engagement and frequency), and reading performance (i.e., comprehension). Participants included 1,260 Flemish fifth-grade students and their 67 teachers. Exploratory and confirmatory factor analyses indicated that both recreational and academic reading motivation comprise 2 factors: autonomous and controlled motivation. This factor structure was found to be invariant across boys and girls. Comparisons of the SRQ-Reading Motivation with subscales of the Motivation for Reading Questionnaire provide evidence for the construct validity of the instrument. Structural equation modeling confirmed that recreational autonomous reading motivation is associated with more positive reading behavior and better performance. In the academic setting, only the equivalent relationship between autonomous reading motivation and leisuretime reading frequency could be corroborated. In this respect, the results confirm the independent contribution of recreational autonomous reading motivation and reading self-concept to reading behavior and performance. No significant indirect relationship between reading motivation and reading comprehension through reading frequency or reading engagement was found. The theoretical and practical significance of the present study is discussed. |
NMF-SVM Based CAD Tool Applied to Functional Brain Images for the Diagnosis of Alzheimer's Disease | This paper presents a novel computer-aided diagnosis (CAD) technique for the early diagnosis of the Alzheimer's disease (AD) based on nonnegative matrix factorization (NMF) and support vector machines (SVM) with bounds of confidence. The CAD tool is designed for the study and classification of functional brain images. For this purpose, two different brain image databases are selected: a single photon emission computed tomography (SPECT) database and positron emission tomography (PET) images, both of them containing data for both Alzheimer's disease (AD) patients and healthy controls as a reference. These databases are analyzed by applying the Fisher discriminant ratio (FDR) and nonnegative matrix factorization (NMF) for feature selection and extraction of the most relevant features. The resulting NMF-transformed sets of data, which contain a reduced number of features, are classified by means of a SVM-based classifier with bounds of confidence for decision. The proposed NMF-SVM method yields up to 91% classification accuracy with high sensitivity and specificity rates (upper than 90%). This NMF-SVM CAD tool becomes an accurate method for SPECT and PET AD image classification. |
Subthalamic stimulation and neuronal activity in the substantia nigra in Parkinson's disease. | High-frequency stimulation of the subthalamic nucleus (STN) is an effective treatment for severe forms of Parkinson's disease (PD). To study the effects of high-frequency STN stimulation on one of the main output pathways of the basal ganglia, single-unit recordings of the neuronal activity of the substantia nigra pars reticulata (SNr) were performed before, during, and after the application of STN electrical stimulation in eight PD patients. During STN stimulation at 14 Hz, no change in either the mean firing rate or the discharge pattern of SNr neurons was observed. STN stimulation at 140 Hz decreased the mean firing rate by 64% and the mean duration of bursting mode activity of SNr neurons by 70%. The SNr residual neuronal activity during 140-Hz STN stimulation was driven by the STN stimulation. How the decrease in rate and modification of firing pattern of SNr-evoked neural activity, during high-frequency STN stimulation, contribute to the improvement of parkinsonian motor disability remains to be elucidated. |
Pyroomacoustics: A Python Package for Audio Room Simulation and Array Processing Algorithms | We present pyroomacoustics, a software package aimed at the rapid development and testing of audio array processing algorithms. The content of the package can be divided into three main components: an intuitive Python object-oriented interface to quickly construct different simulation scenarios involving multiple sound sources and microphones in 2D and 3D rooms; a fast C implementation of the image source model for general polyhedral rooms to efficiently generate room impulse responses and simulate the propagation between sources and receivers; and finally, reference implementations of popular algorithms for beamforming, direction finding, and adaptive filtering. Together, they form a package with the potential to speed up the time to market of new algorithms by significantly reducing the implementation overhead in the performance evaluation step. |
Loughborough University Institutional Repository The potential use of BIM to aid construction waste minimalisation | It is widely acknowledged that the construction industry has a major impact on the environment, both in terms of resource consumption and waste production. The construction industry is responsible for producing a whole variety of different onsite wastes; the amount and type of which depends on factors such as the stage of construction, type of construction work, direct or indirect stakeholders’ design change contribution, and practices throughout the project lifecycle. A number of construction waste minimisation (CWM) techniques and tools are currently available to assist contractors to divert waste away from landfill. However, literature reveals that there are insufficient techniques and tools for reducing construction waste during the design and procurement stages. The last few years saw the emergence of Building Information Modelling (BIM) techniques, which can be adopted to improve sustainable construction performance. BIM is a maturing modelling philosophy, which has been applied to several building-related functions such as visualising designs, automating quantity takeoffs, checking compliance with regulations, and scheduling construction processes. Furthermore, BIM, as a real-time interactive and collaborative communication system, has the potential to help project stakeholders to collaboratively attain waste minimisation for sustainable construction and building throughout design, construction and throughout the lifecycle by improving building construction performance. Hence, this paper, which is part of an ongoing doctoral study, explores the potential application of BIM to design out waste. An in-depth literature review was conducted to provide a foundation for the doctoral study that aims to investigate the use of BIM as a potential platform for building design waste minimisation. The paper explores construction waste origins and causes, current waste reduction practices; examines current industry BIM practices and investigates BIM tools for sustainable project construction and management; and identifies the knowledge gaps in existing literature that pave the way for the subsequent data collection stages. |
End-stage renal failure due to amyloidosis: outcomes in 490 ANZDATA registry cases. | BACKGROUND
There are few reports regarding the long-term renal replacement therapy (RRT) outcomes of amyloidosis.
METHODS
In this retrospective, multi-centre, multi-country registry analysis, all patients with and without amyloidosis who commenced RRT for end-stage renal failure (ESRF) in Australia and New Zealand between 1963 and 2010 were included.
RESULTS
Of 58 422 patients who underwent RRT during the study period, 490 (0.8%) had ESRF secondary to amyloidosis. The median survival of amyloidosis patients on dialysis (2.09 years, 95% CI 1.85-2.32 years) was significantly inferior to that of patients with other causes of ESRF (4.45 years, 95% CI 4.39-4.51 years) (log-rank score 242, P < 0.001). The survival of amyloidosis patients receiving peritoneal dialysis (1.9 years, 95% CI 1.58-2.22) was comparable with those receiving haemodialysis (2.17 years, 95% CI 1.89-2.45) (P = 0.18). Fifty-three (13.8%) amyloidosis patients died of amyloidosis complications. Forty-six patients underwent renal transplantation with first graft survival rates of 45% at 5 years and 26% at 10 years. Nine (16.4%) patients experienced amyloidosis recurrence in their allografts, which led to graft failure in six patients. ESRF patients with amyloidosis experienced inferior median first renal allograft survival (4.55 years, 95% CI 1.96-7.15 versus 10.7 years, 95% CI 10.5-11.0, P = 0.001) and transplant patient survival (6.03 years, 95% CI 2.71-9.36 versus 16.8 years, 95% CI 16.4-17.1, P < 0.001) compared with patients with other causes of ESRF. Respective 10-year patient survival rates were 37 and 69%.
CONCLUSIONS
Amyloidosis was associated with poor patient survival following dialysis and/or renal transplantation, poor renal allograft survival and a significant incidence of disease recurrence in the allograft. An appreciable proportion of amyloid ESRF patients died of amyloidosis-related complications. |
Hospital re-admission associated with adverse drug reactions in patients over the age of 65 years | ContextAdverse drug reactions (ADRs) are responsible for 5 % of hospital admissions, but hospital re-admission induced by ADRs remains poorly documented.ObjectiveThe aim of this study was to estimate the rate of hospital re-admission and the factors associated with re-admission in the patients over the age of 65 years. Secondary, we described the characteristics of cases of ADRs leading to re-admission for drugs other than chemotherapy agents.MethodsData were extracted from hospital discharge summaries provided by the Department of Medical Information of Toulouse University Hospital. All patients over the age of 65 years admitted to the hospital in 2010 for an ADR, identified from ICD-10 codes, were selected. All subsequent admissions of members of this cohort within 1 year of discharge following the index admission were reviewed retrospectively. The risk factors associated with hospital re-admission for ADRs were analyzed. Medical records were used for descriptive analysis of re-admission due to drugs other than chemotherapy agents.ResultsWe found that 553 of the 1000 patients admitted for ADRs in 2010 were re-admitted to hospital within 1 year. Among them, 87 cases were re-admitted for ADRs (estimated rate of 87/1000 re-admission for an ADR within 1 year). A comparison of the patients re-admitted for ADRs (n = 87) with those of patients re-admitted for other causes (n = 410) suggested that only cancer increased the risk of re-admission for ADRs (OR = 7.69 [4.59–12.88] 95 % CI). ADRs due to the same drug combination were the suspected cause of repeat admission in half the cases (other than chemotherapy). Hospital re-admission was considered avoidable in four cases (22 %).ConclusionThis study shows an estimated rate of re-admission for an ADR around 87/1000 within 1 year, and the same drug combination were the suspected cause of repeat admission in half the cases. At least, 11 % of cases were avoidable. |
Physical one-way functions. | Modern cryptographic practice rests on the use of one-way functions, which are easy to evaluate but difficult to invert. Unfortunately, commonly used one-way functions are either based on unproven conjectures or have known vulnerabilities. We show that instead of relying on number theory, the mesoscopic physics of coherent transport through a disordered medium can be used to allocate and authenticate unique identifiers by physically reducing the medium's microstructure to a fixed-length string of binary digits. These physical one-way functions are inexpensive to fabricate, prohibitively difficult to duplicate, admit no compact mathematical representation, and are intrinsically tamper-resistant. We provide an authentication protocol based on the enormous address space that is a principal characteristic of physical one-way functions. |
Photography and the Optical Unconscious | Photography is one of the principal filters through which we engage the world. The contributors to this volume focus on Walter Benjamin's concept of the optical unconscious to investigate how photography has shaped history, modernity, perception, lived experience, politics, race, and human agency. In essays that range from examinations of Benjamin's and Sigmund Freud's writings to the work of Kara Walker and Roland Barthes's famous Winter Garden photograph, the contributors explore what photography can teach us about the nature of the unconscious. They attend to side perceptions, develop latent images, discover things hidden in plain sight, focus on the disavowed, and perceive the slow. Of particular note are the ways race and colonialism have informed photography from its beginning. The volume also contains photographic portfolios by Zoe Leonard, Kelly Wood, and Kristan Horton, whose work speaks to the optical unconscious while demonstrating how photographs communicate on their own terms. The essays and portfolios in Photography and the Optical Unconscious create a collective and sustained assessment of Benjamin's influential concept, opening up new avenues for thinking about photography and the human psyche.
Contributors. Mary Bergstein, Jonathan Fardy, Kristan Horton, Terri Kapsalis, Sarah Kofman, Elisabeth Lebovici, Zoe Leonard, Gabrielle Moser, Mignon Nixon, Thy Phu, Mark Reinhardt, Shawn Michelle Smith, Sharon Sliwinski, Laura Wexler, Kelly Wood, Andres Mario Zervigon |
Dynamic Precedence Effect Modeling for Source Separation in Reverberant Environments | Reverberation continues to present a major problem for sound source separation algorithms. However, humans demonstrate a remarkable robustness to reverberation and many psychophysical and perceptual mechanisms are well documented. The precedence effect is one of these mechanisms; it aids our ability to localize sounds in reverberation. Despite this, relatively little work has been done on incorporating the precedence effect into automated source separation. Furthermore, no work has been carried out on adapting a precedence model to the acoustic conditions under test and it is unclear whether such adaptation, analogous to the perceptual Clifton effect, is even necessary. Hence, this study tests a previously proposed binaural separation/precedence model in real rooms with a range of reverberant conditions. The precedence model inhibitory time constant and inhibitory gain are varied in each room in order to establish the necessity for adaptation to the acoustic conditions. The paper concludes that adaptation is necessary and can yield significant gains in separation performance. Furthermore, it is shown that the initial time delay gap and the direct-to-reverberant ratio are important factors when considering this adaptation. |
Tactile display device using distributed lateral skin stretch | In the past, tactile displays were of one of two kinds: they were either shape displays, or relied on distributed vibrotactile stimulation. A tactile display device is described in this paper which is distinguished by the fact that it relies exclusively on lateral skin stretch stimulation. It is constructed from an array of 64 closely packed piezoelectric actuators connected to a membrane. The deformations of this membrane cause an array of 112 skin contactors to create programmable lateral stress fields in the skin of the finger pad. Some preliminary observations are reported with respect to the sensations that this kind of display can produce. INTRODUCTION Tactile displays are devices used to provide subjects with the sensation of touching objects directly with the skin. Previously reported tactile displays portray distributed tactile stimulation as a one of two possibilities [1]. One class of displays, termed “shape displays”, typically consists of devices having a dense array of skin contactors which can move orthogonally to the surface of the skin in an attempt to display the shape of objects via its spatially sampled approximation. There exist numerous examples of such displays, for recent designs see [2; 3; 4; 5]. In the interest of brevity, the distinction between “pressure displays” and shape displays is not made here. However, an important distinction with regard to the focus of this paper must be made between displays intended to cause no slip between the contactors and the skin and those intended for the opposite case.1 Displays which are intended to be used without slip can be mounted on a carrier device [6; 2]. 1Braille displays can be found in this later category. Another class of displays takes advantage of vibrotactile stimulation. With this technique, an array of tactilly active sites stimulates the skin using an array of contactors vibrating at a fixed frequency. This frequency is selected to maximize the loudness of the sensation (200–300 Hz). Tactile images are associated, not to the quasi-static depth of indentation, but the amplitude of the vibration [7].2 Figure 1. Typical Tactile Display. Shape displays control the rising movement of the contactors (resp. the force applied to). In a vibrotactile display, the contactors oscillate at a fixed frequency. Devices intended to be used as general purpose tactile displays cause stimulation by independently and simultaneously activated skin contactors according to patterns that depend both on space and on time. Such patterns may be thought of as “tactile images”, but because of the rapid adaptation of the skin mechanoreceptors, the images should more accurately be described as “tactile movies”. It is also accepted that the separation between these contactors needs to be of the order of one millimeter so that the resulting percept fuse into one single continuous image. In addition, when contactors apply vibratory signals to the skin at a frequency, which may range from a few Hertz to a few kiloHertz, a perception is derived which may be described 2The Optacon device is a well known example [8]. Proceedings of the Haptic Interfaces for Virtual Environment and Teleoperator Systems Symposium, ASME International Mechanical Engineering Congress & Exposition 2000, Orlando, Florida, USA . pp. 1309-1314 |
Multi-modal human-machine communication for instructing robot grasping tasks | A major challenge for the realization of intelligent robots is to supply them with cognitive abilities in order to allow ordinary users to program them easily and intuitively. One way of such programming is teaching work tasks by interactive demonstration. To make this effective and convenient for the user, the machine must be capable to establish a common focus of attention and be able to use and integrate spoken instructions, visual perceptions, and non-verbal clues like gestural commands. We report progress in building a hybrid architecture that combines statistical methods, neural networks, and finite state machines into an integrated system for instructing grasping tasks by man-machine interaction. The system combines the GRAVIS-robot for visual attention and gestural instruction with an intelligent interface for speech recognition and linguistic interpretation, and an modality fusion module to allow multi-modal task-oriented man-machine communication with respect to dextrous robot manipulation of objects. |
Assessment of arterial stiffness, a translational medicine biomarker system for evaluation of vascular risk. | AIMS
Stiffening of the large arteries is a common feature of aging and is exacerbated by a number of disorders such as hypertension, diabetes, and renal disease. Arterial stiffening is recognized as an important and independent risk factor for cardiovascular events. This article will provide a comprehensive review of the recent advance on assessment of arterial stiffness as a translational medicine biomarker for cardiovascular risk.
DISCUSSIONS
The key topics related to the mechanisms of arterial stiffness, the methodologies commonly used to measure arterial stiffness, and the potential therapeutic strategies are discussed. A number of factors are associated with arterial stiffness and may even contribute to it, including endothelial dysfunction, altered vascular smooth muscle cell (SMC) function, vascular inflammation, and genetic determinants, which overlap in a large degree with atherosclerosis. Arterial stiffness is represented by biomarkers that can be measured noninvasively in large populations. The most commonly used methodologies include pulse wave velocity (PWV), relating change in vessel diameter (or area) to distending pressure, arterial pulse waveform analysis, and ambulatory arterial stiffness index (AASI). The advantages and limitations of these key methodologies for monitoring arterial stiffness are reviewed in this article. In addition, the potential utility of arterial stiffness as a translational medicine surrogate biomarker for evaluation of new potentially vascular protective drugs is evaluated.
CONCLUSIONS
Assessment of arterial stiffness is a sensitive and useful biomarker of cardiovascular risk because of its underlying pathophysiological mechanisms. PWV is an emerging biomarker useful for reflecting risk stratification of patients and for assessing pharmacodynamic effects and efficacy in clinical studies. |
Discussion Paper No . 2003 / 69 Measurement of a Multidimentional Index of Globalization and its Impact on Income Inequality | In this paper we present two composite indices of globalization. The first is based on the Kearney/Foreign Policy magazine and the second is obtained from principal component analysis. They indicate which countries have become most globalized and show how globalization has developed over time. The indices are composed of four components: economic integration, personal contact, technology and political engagement, each generated from a number of variables. A breakdown of the index into major components provides possibilities to identify sources of globalization and associate it with economic policy measures. The empirical results show that a low rank in the globalization process is due to political and personal factors with limited possibility for the developing countries to affect. The high ranked developed countries share similar patterns in distribution of various components. The indices were also used in a regression analysis to study the causal relationship between income inequality and globalization. Globalization indices explain only 7 to 11 per cent of the variations in income inequality among countries. |
A qualitative study on factors that influence women’s choice of delivery in health facilities in Addis Ababa, Ethiopia | BACKGROUND
Facility based delivery for mothers is one of the proven interventions to reduce maternal and neonatal morbidity and mortality. This study identified women's reasons for seeking to give birth in a health facility and captured their perceptions of the quality of care they received during their most recent birth, in a population with high utilization of facility based deliveries.
METHODS
This qualitative study was conducted in eight health centers in Addis Ababa. Women bringing their index child for first vaccinations were invited to participate in an in-depth interview about their last delivery. Sixteen in-depth interviews were conducted. Interviews were conducted by trained researchers using a semi-structured interview guide. The data were transcribed verbatim in Amharic and translated into English. A thematic analysis was conducted to answer specific study questions.
RESULTS
All research participants expressed a preference for facility based delivery because of their awareness of obstetric complications, and related perceptions that facility-birth is safer for the mother and child. Dimensions of quality of care and the cost of services were identified as influencing decisions about whether to seek care in the public or private sector. Media campaigns, information from social networks and women's experiences with healthcare providers and facilities influenced care-seeking decisions.
CONCLUSIONS
The universal preference for facility-based birth by women in this study indicates that, in Addis Ababa, facility based delivery has become a preferred norm. Sources of information for decision-making and the dimensions of quality prioritized by women should be taken into account to develop interventions to promote facility-based births in other settings. |
Implementation of Web Crawler | The World Wide Web is an interlinked collection of billions of documents formatted using HTML. Ironically the very size of this collection has become an obstacle for information retrieval. The user has to shift through scores of pages to come upon the information he/she desires. Web crawlers are the heart of search engines. Web crawlers continuously keep on crawling the web and find any new web pages that have been added to the web, pages that have been removed from the web. Due to growing and dynamic nature of the web; it has become a challenge to traverse all URLs in the web documents and to handle these URLs. A focused crawler is an agent that targets a particular topic and visits and gathers only relevant web pages. In this dissertation I had worked on design and working of web crawler that can be used for copyright infringement. We will take one seed URL as input and search with a keyword, the searching result is based on keyword and it will fetch the web pages where it will find that keyword. This focused based crawler approach retrieve documents that contain particular keyword from the user's query; we are implementing this using breadth-first search. Now, when we retrieved the web pages we will apply pattern recognition over text. We will give one file as input and apply the pattern recognition algorithms. Here, pattern symbolizes text only and check how much text is available on the web page. The algorithms that I had used for pattern search are Knutt-Morri-Pratt, Boyer-Moore, Finite Automata algorithm. |
[Measuring positive behaviour and experience in inpatients with mental disorders--the Hamburg Self-Care Questionnaire (HamSCQ)]. | OBJECTIVES
Treatments of patients with chronic mental disorders are increasingly focusing on salutogenetic aims to support human health and well-being. Up to now, standardized instruments to evaluate these treatment goals are still missing. We present results of analyses of the psychometric properties of the Hamburg Self-Care Questionnaire (HamSCQ). Besides reliability we are focusing on different aspects of validity: factor structure, concurrent validity, and sensitivity to change.
METHODS
A total sample of 7 478 inpatients with mental disorders from four different psychotherapeutic clinics participated in the study. Patients completed self-rating questionnaires at admission and discharge: Besides the HamSCQ we used the Symptom Checklist SCL-14, the Short Form SF-8, the CES-D depression scale, the Inventory of Interpersonal Problems IIP-25 and the AVEM.
RESULTS
The two-dimensional structure of the HamSCQ with the two subscales PACING and POSITIVE EXPERIENCE could be replicated by means of both principal component and confirmatory factor analysis. The two scales correlate with r=0.56. Both scales show a high internal consistency (alpha >or=0.90), they correlate with the selected measures of concurrent validity (except the AVEM scales) with medium (Pacing) or high (Positive Experience) effect sizes, and their mean scores differ significantly from admission to discharge with large effect sizes.
CONCLUSIONS
The HamSCQ proves to be a reliable questionnaire, which is also sensitive to change. The two-dimensional factor structure could be replicated, and some aspects of concurrent validity could be demonstrated, but concerning criterion validity further research is still necessary. Thus we recommend the use of the HamSCQ for inpatients with mental disorders treated in psychotherapeutic/rehabilitative clinics. |
A novel CMOS low-noise amplifier design for 3.1- to 10.6-GHz ultra-wide-band wireless receivers | An ultra-wideband (UWB) 3.1- to 10.6-GHz low-noise amplifier (LNA) employing a common-gate stage for wideband input matching is presented in this paper. Designed in a commercial 0.18-mum 1.8-V standard RFCMOS technology, the proposed UWB LNA achieves fully on-chip circuit implementation, contributing to the realization of a single-chip CMOS UWB receiver. The proposed UWB LNA achieves 16.7plusmn0.8 dB power gain with a good input match (S11<-9 dB) over the 7500-MHz bandwidth (from 3.1 GHz to 10.6 GHz), and an average noise figure of 4.0 dB, while drawing 18.4-mA dc biasing current from the 1.8-V power supply. A gain control mechanism is also introduced for the first time in the proposed design by varying the biasing current of the gain stage without influencing the other figures of merit of the circuit so as to accommodate the UWB LNA in various UWB wireless transmission systems with different link budgets |
Feed-down effect on $\Lambda$ spin polarization | We develop a theoretical framework to study the feed-down effect of higher-lying strange baryons on the spin polarization of $\Lambda$ hyperon. In this framework, we consider two-body decays through strong, electromagnetic, and weak processes and derive general formulas for the angular distribution and spin polarization of the daughter particle by adopting the helicity formalism. Using the realistic experimental data as input, we explore the feed-down contribution to the global and the local $\Lambda$ polarization and find that such contribution suppresses the primordial $\Lambda$ polarization, which is not strong enough to resolve the discrepancy between the current theoretical and experimental results on the azimuthal-angle dependence of $\Lambda$ polarization. Our study may also be useful to the measurement of spin polarization of baryons heavier than $\Lambda$ (e.g., $\Xi^-$) in future experiment. |
Effect of selenium supplementation on CD4+ T-cell recovery, viral suppression and morbidity of HIV-infected patients in Rwanda: a randomized controlled trial | OBJECTIVE
To examine the effect of selenium supplementation on CD4 T-cell counts, viral suppression, and time to antiretroviral therapy (ART) initiation in ART-naive HIV-infected patients in Rwanda.
METHODS
A multicenter, double-blinded, placebo-controlled, randomized clinical trial was conducted. Eligible patients were HIV-infected adults (≥21 years) who had a CD4 cell count between 400 and 650 cells/μl (ART eligibility was ≤350 cells/μl throughout the trial), and were willing to practice barrier methods of birth control. Patients were randomized to receive once-daily 200 μg selenium tablets or identical placebo. They were followed for 24 months with assessments every 6 months. Declines in CD4 cell counts were modeled using linear regressions with generalized estimating equations and effect modification, and the composite outcome (ART eligible or ART initiation) using Cox proportional-hazards regression, both conducted with intention to treat.
RESULTS
Of the 300 participants, 149 received selenium, 202 (67%) were women, and median age was 33.5 years. The rate of CD4 depletion was reduced by 43.8% [95% confidence interval (CI) 7.8-79.8% decrease] in the treatment arm - from mean 3.97 cells/μl per month to mean 2.23 cells/μl per month. We observed 96 composite outcome events - 45 (47%) in the treatment arm. We found no treatment effect for the composite outcome (hazard ratio 1.00, 95% CI 0.66-1.54) or viral suppression (odds ratio 1.18, 95% CI 0.71-1.94). The trial was underpowered for the composite outcome due to a lower-than-anticipated event rate. Adverse events were comparable throughout.
CONCLUSIONS
This randomized clinical trial demonstrated that 24-month selenium supplementation significantly reduces the rate of CD4 cell count decline among ART-naive patients. |
Do hospitalists or physicians with greater inpatient HIV experience improve HIV care in the era of highly active antiretroviral therapy? Results from a multicenter trial of academic hospitalists. | BACKGROUND
Little is known about the effect of provider type and experience on outcomes, resource use, and processes of care of hospitalized patients with human immunodeficiency virus (HIV) infection. Hospitalists are caring for this population with increasing frequency.
METHODS
Data from a natural experiment in which patients were assigned to physicians on the basis of call cycle was used to study the effects of provider type-that is, hospitalist versus nonhospitalist-and HIV-specific inpatient experience on resource use, outcomes, and selected measures of processes of care at 6 academic institutions. Administrative data, inpatient interviews, 30-day follow-up interviews, and the National Death Index were used to measure outcomes.
RESULTS
A total of 1207 patients were included in the analysis. There were few differences in resource use, outcomes, and processes of care by provider type and experience with HIV-infected inpatients. Patients who received hospitalist care demonstrated a trend toward increased length of hospital stay compared with patients who did not receive hospitalist care (6.0 days vs. 5.2 days; P = .13). Inpatient providers with moderate experience with HIV-infected patients were more likely to coordinate care with outpatient providers (odds ratio, 2.40; P = .05) than were those with the least experience with HIV-infected patients, but this pattern did not extend to providers with the highest level of experience.
CONCLUSION
Provider type and attending physician experience with HIV-infected inpatients had minimal effect on the quality of care of HIV-infected inpatients. Approaches other than provider experience, such as the use of multidisciplinary inpatient teams, may be better targets for future studies of the outcomes, processes of care, and resource use of HIV-infected inpatients. |
Higher circulating adiponectin levels are associated with increased risk of atrial fibrillation in older adults. | BACKGROUND
Adiponectin has cardioprotective properties, suggesting that lower levels seen in obesity and diabetes could heighten risk of atrial fibrillation (AF). Among older adults, however, higher adiponectin has been linked to greater incidence of adverse outcomes associated with AF, although recent reports have shown this association to be U-shaped. We postulated that higher adiponectin would be linked to increased risk for AF in older adults in a U-shaped manner.
METHODS
We examined the associations of total and high-molecular-weight (HMW) adiponectin with incident AF among individuals free of prevalent cardiovascular disease (CVD) participating in a population-based cohort study of older adults (n=3190; age=74±5 years).
RESULTS
During median follow-up of 11.4 years, there were 886 incident AF events. Adjusted cubic splines showed a positive and linear association between adiponectin and incident AF. After adjusting for potential confounders, including amino-terminal pro-B-type natriuretic peptide 1-76, the HR (95% CI) for AF per SD increase in total adiponectin was 1.14 (1.05 to 1.24), while that for HMW adiponectin was 1.17 (1.08 to 1.27). Additional adjustment for putative mediators, including subclinical CVD, diabetes, lipids and inflammation, did not significantly affect these estimates.
CONCLUSIONS
The present findings demonstrate that higher, not lower, levels of adiponectin are independently associated with increased risk of AF in older adults despite its documented cardiometabolic benefits. Additional work is necessary to determine if adiponectin is a marker of failed counter-regulatory pathways or whether this hormone is directly harmful in the setting of or as a result of advanced age. |
Behavioral / Systems / Cognitive Functional Connectivity and Brain Networks in Schizophrenia | Mary-Ellen Lynall,1,2 Danielle S. Bassett,1,2,3,4 Robert Kerwin,5 Peter J. McKenna,6 Manfred Kitzbichler,1,2 Ulrich Muller,1,2 and Ed Bullmore1,2,7 1Behavioural and Clinical Neuroscience Institute and 2Department of Psychiatry, University of Cambridge, Cambridge CB2 0SZ, United Kingdom, 3Cognition, and Psychosis Program, Clinical Brain Disorders Branch, Genes, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892, 4Biological Soft Systems Sector, Department of Physics, University of Cambridge, Cambridge CB3 0HE, United Kingdom, 5Institute of Psychiatry, King’s College London, London SE5 8AF, United Kingdom, 6Benito Menni Complex Assistencial en Salut Mental, Centro de Investigacion en Red de Salut Mental, Sant Boi de Llobregat, Barcelona 08840, Spain, and 7Clinical Unit Cambridge, GlaxoSmithKline, Addenbrooke’s Hospital, Cambridge CB2 0QQ, United Kingdom |
Multiple-Use Management of California's Hardwood Resources | Limited information and observations indicate that there are some significant amounts of hardwood residue resources now available in the Central Coast area. Experience gained from man aging and marketing eastern hardwoods is considered as our basis for dealing with western hardwood problems. Inventory of the oak resource is discussed as a preliminary requirement for management. In ad dition, hardwood marketing, research and extension needs are also considered. Evidence indicates that western hardwood use will be improved by better funded programs of re search and extension in residue utilization and marketing. Improved hardwood utilization will yield both direct and indirect benefits. Direct benefits include additional, better quality wood at lower consumer cost and increased tax receipts. Other, indirect benefits include improved hardwood forest management, better fire management, and im proved multiple resource management for watershed, range and recreation values. forest and rangeland owners and industries better market existing and new products?" Several strat egies have been identified including: 1.) research and develop new products (e.g., furniture, panels, pre-fab products) to meet identified demand; 2.) im prove utilization of California timber species; 3.) develop active marketing associations for ex port of forest and range products; 4.) set up pro duction teams to brainstorm, Identify innovative programs, and analyze current and potential markets; 5.) improve marketing techniques to increase demand through advertising and other techniques. Other strategies have been identified, but the above directly apply to the issue of extending utilizaiton [sic] the California hardwood resource. It is our con tention that better land management will occur on California's hardwood lands through better utili zation. Ranchers, for example, would approach hard wood land as areas to be managed rather than con verted to grasslands given a better economic picture through integrated multiple use management (e.g., wildlife, range, hardwood utilization). The purpose of this paper is to explore non-tra ditional approaches to multiple use management of the hardwood lands in Central California. Tradi tionally, the full value of California's oak and hardwood resources has not been widely recognized. Until the late 1950's, oak was a major material that supported the sizable Central Coast charcoal busi ness. More recently, since the Arab Oil Embargo in the early 1970's, the California oak resource has again been recognized as an important fuelwood re source. However, aside from this wood energy use, only a very limited use has been made of the Cal ifornia oak resource. A few sawmills now manufac ture a limited amount of oak lumber, and oaks have |
A Framework for Detecting MAC and IP Spoofing Attacks with Network Characteristics | This paper presents a spoofing attack detection framework based on physical network characteristics (e.g., received signal strength indicator round trip time and link quality indicator) that cannot easily be mimicked by artificial means. Unlike most previous studies that are sensitive to changes in network conditions, we propose a spoofing attack detection method, which is highly robust to the changes of network conditions over time. The proposed framework can monitor devices' physical network characteristics in real time and check if any significant changes have been made in the monitored measurements to effectively detect device spoofing attacks. To demonstrate the feasibility of the proposed framework, we analyzed how the RSSI values of packets were changed with varying physical distances in a real ZigBee (IEEE 802.15.4) network environment. |
A Comprehensive Survey of Wireless Body Area Networks | Recent advances in microelectronics and integrated circuits, system-on-chip design, wireless communication and intelligent low-power sensors have allowed the realization of a Wireless Body Area Network (WBAN). A WBAN is a collection of low-power, miniaturized, invasive/non-invasive lightweight wireless sensor nodes that monitor the human body functions and the surrounding environment. In addition, it supports a number of innovative and interesting applications such as ubiquitous healthcare, entertainment, interactive gaming, and military applications. In this paper, the fundamental mechanisms of WBAN including architecture and topology, wireless implant communication, low-power Medium Access Control (MAC) and routing protocols are reviewed. A comprehensive study of the proposed technologies for WBAN at Physical (PHY), MAC, and Network layers is presented and many useful solutions are discussed for each layer. Finally, numerous WBAN applications are highlighted. |
Noise and its impact on the perception of food and drink | Noise is currently the second most common complaint amongst restaurant-goers, behind poor service. In fact, over the last decade or two, many restaurants have become so loud that some critics now regularly report on the noise levels alongside the quality of the food. In this review, I first highlight the growing problem of noise in restaurants and bars and look at the possible causes. I then critically evaluate the laboratory-based research that has examined the effect of loud background noise on taste perception. I distinguish between the effect of noise on the taste, aroma/flavour, and textural properties of food and drink. Taken together, the evidence now clearly demonstrates that both background noise and loud music can impair our ability to taste food and drink. It would appear that noise selectively impairs the ability to detect tastes such as sweet and sour while leaving certain other taste and flavour experiences relatively unaffected. Possible neuroscientific explanations for such effects are outlined, and directions for future research highlighted. Finally, having identified the growing problem with noise in restaurants, I end by looking at some of the possible solutions and touch on the concept of silent dining. |
A novel fuzzy logic approach to contrast enhancement | Contrast enhancement is one of the most important issues of image processing, pattern recognition and computer vision. The commonly used techniques for contrast enhancement fall into two categories: (1) indirect methods of contrast enhancement and (2) direct methods of contrast enhancement. Indirect approaches mainly modify histogram by assigning new values to the original intensity levels. Histogram speci"cation and histogram equalization are two popular indirect contrast enhancement methods. However, histogram modi"cation technique only stretches the global distribution of the intensity. The basic idea of direct contrast enhancement methods is to establish a criterion of contrast measurement and to enhance the image by improving the contrast measure. The contrast can be measured globally and locally. It is more reasonable to de"ne a local contrast when an image contains textual information. Fuzzy logic has been found many applications in image processing, pattern recognition, etc. Fuzzy set theory is a useful tool for handling the uncertainty in the images associated with vagueness and/or imprecision. In this paper, we propose a novel adaptive direct fuzzy contrast enhancement method based on the fuzzy entropy principle and fuzzy set theory. We have conducted experiments on many images. The experimental results demonstrate that the proposed algorithm is very e!ective in contrast enhancement as well as in preventing over-enhancement. ( 2000 Pattern Recognition Society. Published by Elsevier Science Ltd. All rights reserved. |
5kW Weinberg Converter for Battery Discharging in High-Power Communication Satellites | To be competitive on the telecommunication commercial satellites market, the electrical power subsystems have to be more easily adaptable to the output power level and to the payloads specifications. A trend in recent years has been a steady increase of the payload power of telecommunication spacecraft. The communication satellites of the next generation will increase their capacity of power thus to be able to still lodge more payload on their platform. The powers that will be reached in the next years are above 25 kW. This has manifold implications. Among them we emphasized that it is not possible to use the used constituent modules at the present time whose power is of 1 kW or 2 kW, since up to 25 modules would be needed. To reduce the burden of the thermal control and to utilize more efficiently the power sources, solar arrays and batteries, higher bus voltage have been introduced also in order to reduce the circulating currents. In this paper we present an overall design and experimental results of a high-efficiency non-isolated 5 kW Weinberg converter with conductance control working as a battery discharge regulator module |
Whose Vote Should Count More: Optimal Integration of Labels from Labelers of Unknown Expertise | Modern machine learning-based approaches to computer vision require very large databases of hand labeled images. Some contemporary vision systems already require on the order of millions of images for training (e.g., Omron face detector [9]). New Internet-based services allow for a large number of labelers to collaborate around the world at very low cost. However, using these services brings interesting theoretical and practical challenges: (1) The labelers may have wide ranging levels of expertise which are unknown a priori, and in some cases may be adversarial; (2) images may vary in their level of difficulty; and (3) multiple labels for the same image must be combined to provide an estimate of the actual label of the image. Probabilistic approaches provide a principled way to approach these problems. In this paper we present a probabilistic model and use it to simultaneously infer the label of each image, the expertise of each labeler, and the difficulty of each image. On both simulated and real data, we demonstrate that the model outperforms the commonly used “Majority Vote” heuristic for inferring image labels, and is robust to both noisy and adversarial labelers. |
Impact of 12h shift patterns in nursing: a scoping review. | OBJECTIVES
To provide a comprehensive scoping review of evidence of the impact and effectiveness of 12h shifts in the international nursing literature, supplemented by a review of evidence in other, non-nursing related industries.
DATA SOURCES
A search of the academic literature was undertaken in electronic databases (AMED, MEDLINE, CINAHL, PsychInfo, Scopus, HMIC, the Cochrane Library, Business Source Premier, Econ Lit, ASSIA and Social Policy and Practice).
REVIEW METHODS
A total of 158 potentially relevant nursing research papers and reviews were published between 1973 and 2014. Two reviewers independently reviewed the articles, leaving 85 primary research studies and 10 review papers in the nursing field to be included in the scoping review. Thirty-one relevant primary research papers and reviews were also identified in the non-nursing related industries literature.
RESULTS
Research into 12h nursing shifts fell within five broad themes: 'risks to patients', 'patient experience', 'risks to staff', 'staff experience' and 'impact on the organisation of work'. There was inconclusive evidence of the effects of 12h shift patterns in all five themes, with some studies demonstrating positive impacts and others negative or no impacts. This also mirrors the evidence in other, non-nursing related industries. The quality of research reviewed is generally weak and most studies focus on the risks, experience and work/life balance for staff, with few addressing the impact on patient outcomes and experience of care or work productivity.
CONCLUSIONS
There is insufficient evidence to justify the widespread implementation or withdrawal of 12h shifts in nursing. It is not clearly understood where there are real benefits and where there are real and unacceptable risks to patients and staff. More research focusing on the impact of 12h nursing shifts on patient safety and experience of care and on the long term impact on staff and work organisation is required. |
Metal-based Inkjet Inks for Printed Electronics | A review on applications of metal-based inkjet inks for printed electronics with a particular focus on inks containing metal nanoparticles, complexes and metallo-organic compounds. The review describes the preparation of such inks and obtaining conductive patterns by using various sintering methods: thermal, photonic, microwave, plasma, electrical, and chemically triggered. Various applications of metal-based inkjet inks (metallization of solar cell, RFID antennas, OLEDs, thin film transistors, electroluminescence devices) are reviewed. |
Forecasting Stock Prices from the Limit Order Book Using Convolutional Neural Networks | In today's financial markets, where most trades are performed in their entirety by electronic means and the largest fraction of them is completely automated, an opportunity has risen from analyzing this vast amount of transactions. Since all the transactions are recorded in great detail, investors can analyze all the generated data and detect repeated patterns of the price movements. Being able to detect them in advance, allows them to take profitable positions or avoid anomalous events in the financial markets. In this work we proposed a deep learning methodology, based on Convolutional Neural Networks (CNNs), that predicts the price movements of stocks, using as input large-scale, high-frequency time-series derived from the order book of financial exchanges. The dataset that we use contains more than 4 million limit order events and our comparison with other methods, like Multilayer Neural Networks and Support Vector Machines, shows that CNNs are better suited for this kind of task. |
Evolutionary hierarchical dirichlet processes for multiple correlated time-varying corpora | Mining cluster evolution from multiple correlated time-varying text corpora is important in exploratory text analytics. In this paper, we propose an approach called evolutionary hierarchical Dirichlet processes (EvoHDP) to discover interesting cluster evolution patterns from such text data. We formulate the EvoHDP as a series of hierarchical Dirichlet processes~(HDP) by adding time dependencies to the adjacent epochs, and propose a cascaded Gibbs sampling scheme to infer the model. This approach can discover different evolving patterns of clusters, including emergence, disappearance, evolution within a corpus and across different corpora. Experiments over synthetic and real-world multiple correlated time-varying data sets illustrate the effectiveness of EvoHDP on discovering cluster evolution patterns. |
The New Routing Algorithm for the ARPANET | Absrracr-The new ARPANET routing algorithm is an improvement over the old procedure in that it uses fewer network resources, operates on more realistic estimates of network conditions, reacts faster to important network changes, and does not suffer from long-term loops r oscillations. In the new procedure, each node in the network maintains a database describing the complete network topology and the delays on all lines, and uses the database describing the network to generate a tree representing the minimum delay paths from a given root node to every other network node. Because the traffic in the network can be quite variable, each node periodically measures the delays along its outgoing lines and forwards this information to all other nodes. The delay information propagates quickly through the network so that all nodes can update their databases and continue to route traffic in a consistent and efficient manner. An extensive series of tests were conducted on the ARPANET, showing that line overhead and CPU overhead are 60th less than two percent, most nodes learn of an update within 100 ms, and the algorithm detects congestion and routes packets around congested areas. |
Towards a model of the U.S. stock market: How important is the securities information processor? | Both the scientific community and the popular press have paid much attention to the speed of the Securities Information Processor — the data feed consolidating all trades and quotes across the US stock market. Rather than the speed of the Securities Information Processor, or SIP, we focus here on its importance to efficient, price discovery. Via extensions to a previous market model, we experiment with four different coupling mechanisms which operate across the US stock market. Of the four, we find that the SIP contributes most to efficient price discovery. |
Bias in OLAP Queries: Detection, Explanation, and Removal | On line analytical processing (OLAP) is an essential element of decision-support systems. OLAP tools provide insights and understanding needed for improved decision making. However, the answers to OLAP queries can be biased and lead to perplexing and incorrect insights. In this paper, we propose, a system to detect, explain, and to resolve bias in decision-support queries. We give a simple definition of a biased query, which performs a set of independence tests on the data to detect bias. We propose a novel technique that gives explanations for bias, thus assisting an analyst in understanding what goes on. Additionally, we develop an automated method for rewriting a biased query into an unbiased query, which shows what the analyst intended to examine. In a thorough evaluation on several real datasets we show both the quality and the performance of our techniques, including the completely automatic discovery of the revolutionary insights from a famous 1973 discrimination case. |
Internal validity , performance and dimensionality of the Body Shape Questionnaire among female students in the Kurdistan Iraq Region | The objective of this study to modify and adapt the “Body Shape Questionnaire” for use in the Kurdistan Iraq society; to study the internal validity and the dimensionality of the measure when used with normal sample in the Iraqi society. Across-survey research was complete comprising (160) female students selected in the Salahaddin University, and (120) female students selected in the AL-Hyate University and Chihan University in Kurdistan Iraq. The thirty four items of “Body shape Questionnaire” original version and a questionnaire to evaluate demographic data were used. The result of “internal consistency” of BSQ-34 measured by “Cronbach Alpha” was (0.98) for Kurdish version and (0.97) for Arabic version, indicated that the items of the measure converge to the same concept. The principle component analysis “PCA” of the measure resulted in four-dimension solution accounting by160 Kurdish female student, however the “PCA” for the measure resulted three-dimensions accounting by 120 Arab female students. The old age was (18-20) 53.1% and (21-25) 46.9% for Kurdish sample, while Arabs student old age was (18-20) 55.0% and (21-25) 45.0%. Regarding the final results of BSQ, the mean score of BSQ Arab students were 89.1 3 with SD (33.83). The mean score of BSQ Kurdish female students were 103.03 with SD (43.40). The study found statistically significant race variances in the mean of “BSQ” scores. Kurdish female students showed higher dissatisfaction than Arab female students as to their body shape concern as measured by “BSQ” scale. The adapted versions of the scale seem to maintain the properties of the original one. |
Outlier Detection for High Dimensional Data | The outlier detection problem has important applications in the field of fraud detection, network robustness analysis, and intrusion detection. Most such applications are high dimensional domains in which the data can contain hundreds of dimensions. Many recent algorithms use concepts of proximity in order to find outliers based on their relationship to the rest of the data. However, in high dimensional space, the data is sparse and the notion of proximity fails to retain its meaningfulness. In fact, the sparsity of high dimensional data implies that every point is an almost equally good outlier from the perspective of proximity-based definitions. Consequently, for high dimensional data, the notion of finding meaningful outliers becomes substantially more complex and non-obvious. In this paper, we discuss new techniques for outlier detection which find the outliers by studying the behavior of projections from the data set. |
Dynamic Supernodes in Sparse Cholesky Update/Downdate and Triangular Solves | The supernodal method for sparse Cholesky factorization represents the factor L as a set of supernodes, each consisting of a contiguous set of columns of L with identical nonzero pattern. A conventional supernode is stored as a dense submatrix. While this is suitable for sparse Cholesky factorization where the nonzero pattern of L does not change, it is not suitable for methods that modify a sparse Cholesky factorization after a low-rank change to A (an update/downdate, Ā = A ± WWT). Supernodes merge and split apart during an update/downdate. Dynamic supernodes are introduced which allow a sparse Cholesky update/downdate to obtain performance competitive with conventional supernodal methods. A dynamic supernodal solver is shown to exceed the performance of the conventional (BLAS-based) supernodal method for solving triangular systems. These methods are incorporated into CHOLMOD, a sparse Cholesky factorization and update/downdate package which forms the basis of x = A\b MATLAB when A is sparse and symmetric positive definite. |
SIM: A C++ Library for Discrete Event Simulation | In this report we give a full description of sim, a C++ library for discrete event simulation. The sim library supports both an event and process-oriented approach to developing simulations. Events as well as entities (which may be considered as events with states signifying episodes in its lifetime) are provided as abstract classes that must be reened by the application programmer to deene the actual events and entities participating in the simulation. The sim library is integrated with the hush library, thus ooering powerful graphic and animation facilities. However, the sim library may also be used independently, on both Unix and MS-Dos platforms. This report presents an overview of the classes constituting the sim library (including the classes event, entity, generator, resource, queue, histogram and analysis) as well as two standard examples illustrating the deployment of the classes in writing simulation programs. Also, an example is given of how to create a graphical animation of a particular simulation. The appendix contains, moreover, a more extensive example of a jobshop simulation illustrating how the analysis class may be used to obtain measurements of complex queing behavior. |
On-demand Injection of Lexical Knowledge for Recognising Textual Entailment | We approach the recognition of textual entailment using logical semantic representations and a theorem prover. In this setup, lexical divergences that preserve semantic entailment between the source and target texts need to be explicitly stated. However, recognising subsentential semantic relations is not trivial. We address this problem by monitoring the proof of the theorem and detecting unprovable sub-goals that share predicate arguments with logical premises. If a linguistic relation exists, then an appropriate axiom is constructed on-demand and the theorem proving continues. Experiments show that this approach is effective and precise, producing a system that outperforms other logicbased systems and is competitive with state-of-the-art statistical methods. |
Motivational variables in second-language acquisition. | 1 During the summer of 2005, I discovered that there was not a copy of my dissertation available from the library at McGill University. I was, however, able to obtain a copy of it on microfilm from another university that had initially obtained it on interlibrary loan. I am most grateful to Vicki Galbraith who typed this version from that copy, which except for some minor variations due to differences in type size and margins (plus this footnote, of course) is identical to that on the microfilm. ACKNOWLEDGEMENTS 1 The writer is grateful to Dr. J. T. McIlhone, Associate General Director in Charge of English Classes of the Montreal Catholic School Board, for his kind cooperation in making subjects available, and to the Principals and French teachers of each high school for their assistance and cooperation during the testing programs. advice on the statistical analysis. In addition, the writer would like to express his appreciation to Mr. K. Tunstall for his assistance in the difficult task of interviewing the parents of each student. Finally, the writer would like to express his gratitude to Janet W. Gardner for her invaluable assistance in all phases of the research program. |
Overnight versus progressive conversion of multiple daily-dose divalproex to once-daily divalproex extended release: which strategy is better tolerated by adults with intellectual disabilities? | Divalproex (DVP) delayed release and DVP extended release (DVP ER) are approved by the Food and Drug Administration for bipolar disorder, epilepsy, and migraine prophylaxis. Divalproex ER is given once daily, improving compliance and reducing adverse events. Overnight switch to DVP ER is advised in the package insert but could produce more adverse events in this susceptible population. In this pilot study, we compared tolerability of overnight versus gradual switching to DVP ER in 16 adults with intellectual and developmental disabilities receiving DVP, in 9 for epilepsy and in all 16 for comorbid bipolar disorder. The study design was open with parallel groups. Sixteen subjects with intellectual and developmental disabilities were randomized to overnight or gradual conversion for 4 to 6 days. A blinded rater completed the Multidimensional Observation Scale for Elderly Subjects on days +1, +4, and +8 after the switch began. We found no major differences between the 2 groups at each time point. Neither group of subjects, except for 1 subject in the overnight group, manifested sedation, seizures, worsening of tremor, or gastrointestinal adverse events. One subject in the overnight group manifested acute diarrhea and vomiting, followed by a very brief tonic leg seizure 6 days later. Larger studies are warranted. |
Energy of the Taub Cosmological Solution | We calculate the total energy of Taub’s 1951 exact solution for a Bianchi type-IX geometry using several different energy-localization procedures, including the prescriptions of Einstein, Papapetrou, Landau–Lifshitz and Möller. We compare these results to those for other anisotropic geometries, and comment on their relationship to Rosen’s conjecture about the total energy of the universe. |
Full regeneration of segmental bone defects using porous titanium implants loaded with BMP-2 containing fibrin gels. | Regeneration of load-bearing segmental bone defects is a major challenge in trauma and orthopaedic surgery. The ideal bone graft substitute is a biomaterial that provides immediate mechanical stability, while stimulating bone regeneration to completely bridge defects over a short period. Therefore, selective laser melted porous titanium, designed and fine-tuned to tolerate full load-bearing, was filled with a physiologically concentrated fibrin gel loaded with bone morphogenetic protein-2 (BMP-2). This biomaterial was used to graft critical-sized segmental femoral bone defects in rats. As a control, porous titanium implants were either left empty or filled with a fibrin gels without BMP-2. We evaluated bone regeneration, bone quality and mechanical strength of grafted femora using in vivo and ex vivo µCT scanning, histology, and torsion testing. This biomaterial completely regenerated and bridged the critical-sized bone defects within eight weeks. After twelve weeks, femora were anatomically re-shaped and revealed open medullary cavities. More importantly, new bone was formed throughout the entire porous titanium implants and grafted femora regained more than their innate mechanical stability: torsional strength exceeded twice their original strength. In conclusion, combining porous titanium implants with a physiologically concentrated fibrin gels loaded with BMP-2 improved bone regeneration in load-bearing segmental defects. This material combination now awaits its evaluation in larger animal models to show its suitability for grafting load-bearing defects in trauma and orthopaedic surgery. |
A Circularly-Polarized Isoflux Antenna Based on Anisotropic Metasurface | Theory, design, realization and measurements of an X-band isoflux circularly polarized antenna for LEO satellite platforms are presented. The antenna is based on a metasurface composed by a dense texture of sub-wavelength metal patches on a grounded dielectric slab, excited by a surface wave generated by a coplanar feeder. The antenna is extremely flat (1.57 mm) and light (less than 1 Kg) and represents a competitive solution for space-to-ground data link applications. |
EXPECTATION BUBBLES IN A SPIN MODEL OF MARKETS: INTERMITTENCY FROM FRUSTRATION ACROSS SCALES | A simple spin model is studied, motivated by the dynamics of traders in a market, where expectation bubbles and crashes occur. The dynamics is governed by interactions, which are frustrated across different scales: while ferromagnetic couplings connect each spin to its local neighborhood, an additional coupling relates each spin to the global magnetization. This new coupling is allowed to be anti-ferromagnetic. The resulting frustration causes a metastable dynamics with intermittency and phases of chaotic dynamics. The model reproduces main observations of real economic markets as power-law distributed returns and clustered volatility. |
PET and SPECT in epilepsy: A critical review | Molecular imaging with ictal and interictal single-photon emission computed tomography (SPECT) as well as positron emission tomography (PET) rank among the established functional imaging tests for the presurgical evaluation of epileptic onset zone in patients with intractable partial epilepsy. In temporal lobe epilepsy the sensitivity of these methods was shown to be excellent, in particular if a multimodal platform is used, which combines the functional imaging with the additional morphological information of magnetic resonance imaging (MRI), but was lower in extra temporal lobe epilepsy. Functional imaging with SPECT and PET reflects seizure related changes of cerebral perfusion, glucose-metabolism and neuroreceptor status. In this review the usefulness of SPECT and PET imaging in clinical routine in epilepsy as well as the role of different neuroreceptor PET-tracer, which were used in epilepsy are discussed. The use of perfusion SPECT tracer allows the investigation of ictal activations, but the low temporal resolution of ictal perfusion SPECT often results in the detection of both the ictal onset zone as well as the propagation pathways, an area that has not always need to be resected in order to render a patient seizure free. The additional use of interictal PET with fluorine-18 fluorodeoxyglucose which measures regional cerebral metabolism or interictal perfusion SPECT enhance the informational value of ictal SPECT and were shown to be important tools to better define the ictal onset and surround inhibition zones. In recent years PET imaging of different cerebral neuroreceptor-systems inter alia GABA(A) receptors, serotonin receptors (5-HT(1A)), opioid receptors as well as dopamine receptors was used to investigate the neurochemical basis of epilepsy, the role of these neurotransmitters for the epileptogenesis as well as the spread of epileptic activity during seizures and partially entered in clinical routine. Currently some of these radioligands are also used to investigate new treatment approaches. |
Vehicular Communications: A Network Layer Perspective | Vehicular communications, referring to information exchange among vehicles, infrastructures, etc., have attracted a lot of attention recently due to great potential to support intelligent transportation, various safety applications, and on-road infotainment. In this paper, we provide a comprehensive overview of a recent research on enabling efficient and reliable vehicular communications from the network layer perspective. First, we introduce general applications and unique characteristics of vehicular communication networks and the corresponding classifications. Based on different driving patterns, we categorize vehicular networks into manual driving vehicular networks and automated driving vehicular networks, and then discuss the available communication techniques, network structures, routing protocols, and handoff strategies applied in these vehicular networks. Finally, we identify the challenges confronted by the current vehicular networks and present the corresponding research opportunities. |
Logic-Based Question Answering | Question answering systems aim to provide concise and correct responses to arbitrary questions, communicating with the user in a natural language. This way they help making the knowledge of large textual sources accessible in an intuitive manner which goes beyond the capabilities of conventional search engines. In the LogAnswer project the universities of Hagen and Koblenz cooperate to build a German language question answering system which combines computational linguistics and automated reasoning to deduce answers from a knowledge base derived from Wikipedia. |
More Than Just a Lock in the Browser: A Global Consumer-Company Transaction Security Perspective | The views about the security in B2C e-commerce often point to a particular aspect. The role and the real value of these matters can be understood only from a broad perspective. This paper examines the security as a global problem that it is a first order concern for consumers and companies. |
Effects of genotype and environment on the content and composition of phytochemicals and dietary fiber components in rye in the HEALTHGRAIN diversity screen. | The effects of genotype and environment on the content of bioactive components in rye were determined with four varieties being grown on one site for three years and on three additional sites in the third year and a fourth variety being included in all trials except year 1. Clear differences were observed in the extent to which the contents of dietary fiber components (arabinoxylan, beta-glucan, total dietary fiber) and phytochemicals (folates, alkylresorcinols, sterols, tocols, phenolic acids) varied between varieties and between the same varieties grown in different sites (United Kingdom, France, Hungary, Poland) and years (2005-2007 in Hungary), with sterols being the most stable and phenolic acids the least. However, no single variety could be selected as having the highest overall level of bioactive components or as being more stable in comparison across environments. |
Analysis and Design of Average Current Mode Control Using a Describing-Function-Based Equivalent Circuit Model | This paper proposes a small-signal model for average current mode control based on an equivalent circuit. The model uses a three-terminal equivalent circuit model based on a linearized describing function method to include the feedback effect of the sideband frequency components of the inductor current. The model extends the results obtained in peak current mode control to average current mode control. The proposed small-signal model is accurate up to half switching frequency, predicting the subharmonic instability. The proposed model is verified using SIMPLIS simulation and hardware experiments, which show good agreement with the measurement results. Based on the proposed model, new feedback design guidelines are presented. The proposed design guidelines are compared with several conventional, widely used design criteria. By designing the external ramp following the proposed design guidelines, the quality factor of the double poles at half of the switching frequency in the control-to-output transfer function can be precisely controlled. This helps the feedback loop design to achieve wide control bandwidth and proper damping. |
A General Framework for Agglomerative Hierarchical Clustering Algorithms | This paper presents a general framework for agglomerative hierarchical clustering based on graphs. Different hierarchical agglomerative clustering algorithms can be obtained from this framework, by specifying an inter-cluster similarity measure, a subgraph of the 13-similarity graph, and a cover routine. We also describe two methods obtained from this framework called hierarchical compact algorithm and hierarchical star algorithm. These algorithms have been evaluated using standard document collections. The experimental results show that our methods are faster and obtain smaller hierarchies than traditional hierarchical algorithms while achieving a similar clustering quality |
Aerial display of vibrotactile sensation with high spatial-temporal resolution using large-aperture airborne ultrasound phased array | We fabricated a tactile display which can generate vibrotactile sensation on human skin on which no equipment is mounted. It utilizes focused airborne ultrasound radiation pressure for stimulation. The workspace of our new tactile display is widened to a cube of 1 m × 1 m × 1 m, which allows users free motions in it. In order to widen the workspace, our new prototype integrates multiple ultrasound transducer units and achieves a large aperture airborne ultrasound phased array. As the workspace is widened, it has become possible to stimulate arbitrary regions all over a human body. The amplitude of imposed radiation pressure can be time-variant. The profiles of generated vibrotactile stimuli can be designed with a temporal resolution of 0.5 ms and 320-level quantization of radiation pressure amplitude. It is easy to choose a recorded waveform and reproduce it as vibrotactile stimuli at an arbitrary spatial point. This paper introduces how our new tactile display works and reports its performance evaluation. |
Independent drive of integrated multicolor (RGBY) micro-LED array using regularly arrayed InGaN based nanocolumns | We demonstrate monolithic integration of blue-, green-, yellow-, and red-emitting micro light emitting diodes (LEDs) and their independent drive using matrix wiring electrodes. The four-color (RGBY) micro-LEDs are prepared on the same template by using regularly arrayed InGaN based nanocolumns with different column diameters and periods via selective area growth. |
Lyapunov-function-based flux and speed observer for AC induction motor sensorless control and parameters estimation | AC induction motors have become very popular for motion-control applications due to their simple and reliable construction. Control of drives based on ac induction motors is a quite complex task. Provided the vector-control algorithm is used, not only the rotor speed but also the position of the magnetic flux inside the motor during the control process should be known. In most applications, the flux sensors are omitted and the magnetic-flux phasor position has to be calculated. However, there are also applications in which even speed sensors should be omitted. In such a situation, the task of state reconstruction can be solved only from voltage and current measurements. In the current paper, a method based on deterministic evaluation of measurement using the state observer based on the Lyapunov function is presented. The method has been proven in testing on a real ac induction machine. |
Weight-averaged consistency targets improve semi-supervised deep learning results | The recently proposed Temporal Ensembling has achieved state-of-the-art results in several semi-supervised learning benchmarks. It maintains an exponential moving average of label predictions on each training example, and penalizes predictions that are inconsistent with this target. However, because the targets change only once per epoch, Temporal Ensembling becomes unwieldy when learning large datasets. To overcome this problem, we propose Mean Teacher, a method that averages model weights instead of label predictions. As an additional benefit, Mean Teacher improves test accuracy and enables training with fewer labels than Temporal Ensembling. Without changing the network architecture, Mean Teacher achieves an error rate of 4.35% on SVHN with 250 labels, outperforming Temporal Ensembling trained with 1000 labels. We also show that a good network architecture is crucial to performance. Combining Mean Teacher and Residual Networks, we improve the state of the art on CIFAR-10 with 4000 labels from 10.55% to 6.28%, and on ImageNet 2012 with 10% of the labels from 35.24% to 9.11%. |
Lung Cancer Occurrence in Never-Smokers: An Analysis of 13 Cohorts and 22 Cancer Registry Studies | BACKGROUND
Better information on lung cancer occurrence in lifelong nonsmokers is needed to understand gender and racial disparities and to examine how factors other than active smoking influence risk in different time periods and geographic regions.
METHODS AND FINDINGS
We pooled information on lung cancer incidence and/or death rates among self-reported never-smokers from 13 large cohort studies, representing over 630,000 and 1.8 million persons for incidence and mortality, respectively. We also abstracted population-based data for women from 22 cancer registries and ten countries in time periods and geographic regions where few women smoked. Our main findings were: (1) Men had higher death rates from lung cancer than women in all age and racial groups studied; (2) male and female incidence rates were similar when standardized across all ages 40+ y, albeit with some variation by age; (3) African Americans and Asians living in Korea and Japan (but not in the US) had higher death rates from lung cancer than individuals of European descent; (4) no temporal trends were seen when comparing incidence and death rates among US women age 40-69 y during the 1930s to contemporary populations where few women smoke, or in temporal comparisons of never-smokers in two large American Cancer Society cohorts from 1959 to 2004; and (5) lung cancer incidence rates were higher and more variable among women in East Asia than in other geographic areas with low female smoking.
CONCLUSIONS
These comprehensive analyses support claims that the death rate from lung cancer among never-smokers is higher in men than in women, and in African Americans and Asians residing in Asia than in individuals of European descent, but contradict assertions that risk is increasing or that women have a higher incidence rate than men. Further research is needed on the high and variable lung cancer rates among women in Pacific Rim countries. |
Graph Minors for Preserving Terminal Distances Approximately - Lower and Upper Bounds | Given a graph where vertices are partitioned into k terminals and non-terminals, the goal is to compress the graph (i.e., reduce the number of non-terminals) using minor operations while preserving terminal distances approximately. The distortion of a compressed graph is the maximum multiplicative blow-up of distances between all pairs of terminals. We study the trade-off between the number of non-terminals and the distortion. This problem generalizes the Steiner Point Removal (SPR) problem, in which all non-terminals must be removed. We introduce a novel black-box reduction to convert any lower bound on distortion for the SPR problem into a super-linear lower bound on the number of non-terminals, with the same distortion, for our problem. This allows us to show that there exist graphs such that every minor with distortion less than 2 / 2.5 / 3 must have Ω(k2) / Ω(k5/4) / Ω(k6/5) non-terminals, plus more trade-offs in between. The black-box reduction has an interesting consequence: if the tight lower bound on distortion for the SPR problem is super-constant, then allowing any O(k) non-terminals will not help improving the lower bound to a constant. We also build on the existing results on spanners, distance oracles and connected 0-extensions to show a number of upper bounds for general graphs, planar graphs, graphs that exclude a fixed minor and bounded treewidth graphs. Among others, we show that any graph admits a minor with O(log k) distortion and O(k2) non-terminals, and any planar graph admits a minor with 1 + ε distortion and Õ((k/ε)2) non-terminals. 1998 ACM Subject Classification G.2.2 Graph Theory |
An improved unified scalable radix-2 Montgomery multiplier | This paper describes an improved version of the Tenca-Koc unified scalable radix-2 Montgomery multiplier with half the latency for small and moderate precision operands and half the queue memory requirement. Like the Tenca-Koc multiplier, this design is reconfigurable to accept any input precision in either GF(p) or GF(2/sup n/) up to the size of the on-chip memory. An FPGA implementation can perform 1024-bit modular exponentiation in 16 ms using 5598 4-input lookup tables, making it the fastest unified scalable design yet reported. |
Powering the Future of Industry: High-Power Adjustable Speed Drive Topologies | The HP-ASD technology has experienced a huge development in the last decade. This can be appreciated by the large number of recently introduced drive configurations on the market. In addition, many industrial applications are reaching MV operation and megawatt range or have experienced changes in requirements on efficiency, performance, and power quality, making the use of HP-ASDs more attractive. It can be concluded that, HP-ASDs is an enabling technology ready to continue powering the future of industry for the decades to come. |
Text Classification Using Association Rules, Dependency Pruning and Hyperonymization | We present new methods for pruning and enhancing itemsets for text classification via association rule mining. Pruning methods are based on dependency syntax and enhancing methods are based on replacing words by their hyperonyms of various orders. We discuss the impact of these methods, compared to pruning based on tfidf rank of words. |
The DLR-KUKA success story: robotics research improves industrial robots | This paper discusses the joint venture between the German Aerospace Center (DLR) Institute of Robotics and Mechatronics and the German robot manufacturer, KUKA Robotics GmbH, for the successful transfer of the knowledge in robot dynamics and control, human robot interaction, and sensory feedback as originally developed for the remote control of space robots to industrial robotics. This technology transfer venture aims to promote more industrial sensory feedback applications with particular focus on the fusion of vision and force, while merging service and industrial robots into the future. As such, the aim is to transfer new robonaut technologies and ultra-lightweight, torque-controlled, kinematically redundant arms with multifingered articulated hands into the terrestrial robot industry. |
AllConcur: Leaderless Concurrent Atomic Broadcast (Extended Version) | Many distributed systems require coordination between the components involved. With the steady growth of such systems, the probability of failures increases, which necessitates scalable fault-tolerant agreement protocols. The most common practical agreement protocol, for such scenarios, is leader-based atomic broadcast. In this work, we propose ALLCONCUR, a distributed system that provides agreement through a leaderless concurrent atomic broadcast algorithm, thus, not suffering from the bottleneck of a central coordinator. In ALLCONCUR, all components exchange messages concurrently through a logical overlay network that employs early termination to minimize the agreement latency. Our implementation of ALLCONCUR supports standard sockets-based TCP as well as high-performance InfiniBand Verbs communications. ALLCONCUR can handle up to 135 million requests per second and achieves 17× higher throughput than today’s standard leader-based protocols, such as Libpaxos. Thus, ALLCONCUR is highly competitive with regard to existing solutions and, due to its decentralized approach, enables hitherto unattainable system designs in a variety of fields. |
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