272 research outputs found

    CURRENT DISTRIBUTION OF AC SURFACE DISCHARGES AND ASSOCIATED CHEMISTRY

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    It is shown that ac discharges propagating at an air / dielectric interface, though of planar structure, behave, till a critical voltage Vcrit, as corona discharges in an air gap, with similar propagation fields for the filamentary discharge components and similar glow components. This leads to consider the surface discharges as gas discharges propagating above the dielectric surface. Beyond Vcrit, the retention of charges by the dielectric surface becomes ineffective, due to the gas heating in the filamentary channels and to the heat subsequently transferred from these channels to the surface. In return, the surface gives its energy excess back to the discharge, so opening the way, on the surface, to leader-like discharges of higher conductivity, needing about 10 times lower fields to propagate

    BIOLOGICAL APPLICATIONS OF ATMOSPHERIC PRESSURE DIELECTRIC BARRIER DISCHARGES

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    International audienceA reduction of more than 4 orders of magnitude of survivors was obtained by exposing a Bacillus Stearothermophilus spores - contaminated surface to an atmospheric pressure DBD post-discharge for 20 minutes. Decontamination mechanisms are investigated assuming that (i) inactivation is obtained when the bacteria DNA is fragmented, (ii) the protein coats are the main protection of the cell core DNA in the case of bacteria spores. The degradation of DNA (plasmid) and protein (RNAse A) samples submitted to the postdischarge is evaluated according to the operating conditions: gas composition, treatment time and sample state, i.e. hydrated or dried samples

    Real-time collaborative coding in a web IDE

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    This paper describes Collabode, a web-based Java integrated development environment designed to support close, synchronous collaboration between programmers. We examine the problem of collaborative coding in the face of program compilation errors introduced by other users which make collaboration more difficult, and describe an algorithm for error-mediated integration of program code. Concurrent editors see the text of changes made by collaborators, but the errors reported in their view are based only on their own changes. Editors may run the program at any time, using only error-free edits supplied so far, and ignoring incomplete or otherwise error-generating changes. We evaluate this algorithm and interface on recorded data from previous pilot experiments with Collabode, and via a user study with student and professional programmers. We conclude that it offers appreciable benefits over naive continuous synchronization without regard to errors and over manual version control.National Science Foundation (U.S.) (award IIS- 0447800

    Making Quantum Computing Open: Lessons from Open-Source Projects

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    Quantum computing (QC) is an emerging computing paradigm with potential to revolutionize the field of computing. QC is a field that is quickly developing globally and has high barriers of entry. In this paper we explore both successful contributors to the field as well as wider QC community with the goal of understanding the backgrounds and training that helped them succeed. We gather data on 148 contributors to open-source quantum computing projects hosted on GitHub and survey 46 members of QC community. Our findings show that QC practitioners and enthusiasts have diverse backgrounds, with most of them having a PhD and trained in physics or computer science. We observe a lack of educational resources on quantum computing. Our goal for these findings is to start a conversation about how best to prepare the next generation of QC researchers and practitioners

    TurKit: Tools for iterative tasks on mechanical Turk

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    Mechanical Turk (MTurk) is an increasingly popular web service for paying people small rewards to do human computation tasks. Current uses of MTurk typically post independent parallel tasks. We are exploring an alternative iterative paradigm, in which workers build on or evaluate each other's work. We describe TurKit, a new toolkit for deploying iterative tasks to MTurk, with a familiar imperative programming paradigm that effectively uses MTurk workers as subroutines.National Science Foundation (U.S.). (Grant number IIS-0447800)Quanta Computer (Firm)Massachusetts Institute of Technology. Center for Collective Intelligenc

    TurKit: Human Computation Algorithms on Mechanical Turk

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    Mechanical Turk (MTurk) provides an on-demand source of human computation. This provides a tremendous opportunity to explore algorithms which incorporate human computation as a function call. However, various systems challenges make this difficult in practice, and most uses of MTurk post large numbers of independent tasks. TurKit is a toolkit for prototyping and exploring algorithmic human computation, while maintaining a straight-forward imperative programming style. We present the crash-and-rerun programming model that makes TurKit possible, along with a variety of applications for human computation algorithms. We also present case studies of TurKit used for real experiments across different fields.Xerox CorporationNational Science Foundation (U.S.) (Grant No. IIS- 0447800)Quanta ComputerMassachusetts Institute of Technology. Center for Collective Intelligenc

    Software development with real-time collaborative editing

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (p. 129-133).This thesis presents Collabode, a web-based integrated development environment for Java. With real-time collaborative editing, multiple programmers can use Collabode to edit the same source code at the same time. Collabode introduces error-mediated integration, where multiple editors see the text of one another's changes while being isolated from errors and in-progress work, and error-free changes are integrated automatically. Three models of collaborative programming are presented and evaluated using Collabode. Classroom programming brings zero-setup web-based programming to computer science students working in a classroom or lab. Test-driven pair programming combines two existing software development strategies to create a model with clear roles and explicit tool support. And micro-outsourcing enables one programmer to easily request and integrate very small contributions from many distributed assistants, demonstrating how a system for highly-collaborative programming enables a development model infeasible with current tools. To show that highly-collaborative programming, using real-time collaborative editing of source code, is practical, useful, and enables new models of software development, this thesis presents a series of user studies. A study with pairs of both student and professional programmers shows that error-mediated integration allows them to work productively in parallel. In a semester-long deployment of Collabode, students in an MIT software engineering course used the system for classroom programming. In a lab study of a Collabode prototype, professional programmers used test-driven pair programming. Finally, a study involving both in-lab participants and contractors hired online demonstrated how micro-outsourcing allowed participants to approach programming in a new way, one enabled by collaborative editing, automatic error-mediated integration, and a web-based environment requiring no local setup.by Max Goldman.Ph.D

    Don’t turn your back on the symptoms of psychosis : a proof-of-principle, quasi-experimental public health trial to reduce the duration of untreated psychosis in Birmingham, UK

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    Background: Reducing the duration of untreated psychosis (DUP) is an aspiration of international guidelines for first episode psychosis; however, public health initiatives have met with mixed results. Systematic reviews suggest that greater focus on the sources of delay within care pathways, (which will vary between healthcare settings) is needed to achieve sustainable reductions in DUP (BJP 198: 256-263; 2011). Methods/Design: A quasi-experimental trial, comparing a targeted intervention area with a ‘detection as usual’ area in the same city. A proof-of–principle trial, no a priori assumptions are made regarding effect size; key outcome will be an estimate of the potential effect size for a definitive trial. DUP and number of new cases will be collected over an 18-month period in target and control areas and compared; historical data on DUP collected in both areas over the previous three years, will serve as a benchmark. The intervention will focus on reducing two significant DUP component delays within the overall care pathway: delays within the mental health service and help-seeking delay. Discussion: This pragmatic trial will be the first to target known delays within the care pathway for those with a first episode of psychosis. If successful, this will provide a generalizable methodology that can be implemented in a variety of healthcare contexts with differing sources of delay. Trial registration: http://www.controlled-trials.com/ISRCTN45058713 Keywords: Public mental health campaign, First-episode psychosis, Early detection, Duration of untreated psychosis, Youth mental healt

    Do motor control genes contribute to interindividual variability in decreased movement in patients with pain?

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    <p>Abstract</p> <p>Background</p> <p>Because excessive reduction in activities after back injury may impair recovery, it is important to understand and address the factors contributing to the variability in motor responses to pain. The current dominant theory is the "fear-avoidance model", in which the some patients' heightened fears of further injury cause them to avoid movement. We propose that in addition to psychological factors, neurochemical variants in the circuits controlling movement and their modification by pain may contribute to this variability. A systematic search of the motor research literature and genetic databases yielded a prioritized list of polymorphic motor control candidate genes. We demonstrate an analytic method that we applied to 14 of these genes in 290 patients with acute sciatica, whose reduction in movement was estimated by items from the Roland-Morris Disability Questionnaire.</p> <p>Results</p> <p>We genotyped a total of 121 single nucleotide polymorphisms (SNPs) in 14 of these genes, which code for the dopamine D2 receptor, GTP cyclohydrolase I, glycine receptor α1 subunit, GABA-A receptor α2 subunit, GABA-A receptor ÎČ1 subunit, α-adrenergic 1C, 2A, and 2C receptors, serotonin 1A and 2A receptors, cannabinoid CB-1 receptor, M1 muscarinic receptor, and the tyrosine hydroxylase, and tachykinin precursor-1 molecules. No SNP showed a significant association with the movement score after a Bonferroni correction for the 14 genes tested. Haplotype analysis of one of the blocks in the GABA-A receptor ÎČ1 subunit showed that a haplotype of 11% frequency was associated with less limitation of movement at a nominal significance level value (p = 0.0025) almost strong enough to correct for testing 22 haplotype blocks.</p> <p>Conclusion</p> <p>If confirmed, the current results may suggest that a common haplotype in the GABA-A ÎČ1 subunit acts like an "endogenous muscle relaxant" in an individual with subacute sciatica. Similar methods might be applied a larger set of genes in animal models and human laboratory and clinical studies to understand the causes and prevention of pain-related reduction in movement.</p
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