518 research outputs found

    A market for trading software issues

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    The security of software is becoming increasingly important. Open source software forms much of our digital infrastructure. It, however, contains vulnerabilities which have been exploited, attracted public attention, and caused large financial damages. This article proposes a solution to shortcomings in the current economic situation of open source software development. The main idea is to introduce price signals into the peer production of software. This is achieved through a trading market for futures contracts on the status of software issues. Users, who value secure software, gain the possibility to predict outcomes and incentivize work, strengthening collaboration and information sharing in open source software development. The design of such a trading market is discussed and a prototype introduced. The feasibility of the trading market design is corroborated in a proof-of-concept implementation and simulation. Preliminary results show that the implementation works and can be used for future experiments. Several directions for future research result from this article, which contributes to peer production, software development practices, and incentives design

    Marktplatz zur Koordinierung und Finanzierung von Open Source Software

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    Open Source ist ein zunehmend beliebter Kollaborationsmechanismus für die Entwicklung von Software, auch in Unternehmen. Unsere Arbeit schafft die fehlende Verbindung zwischen Open Source Projekten, Unternehmen und Märkten. Ohne diese Verbindung wurden Koordinations- und Finanzierungsprobleme sichtbar, die zu schwerwiegenden Sicherheitslücken führen. In diesem Paper entwickeln wir acht Design Features, die ein Marktplatz für Open Source haben sollte, um diese Probleme zu beseitigen. Wir begründen jedes Design Feature mit den bestehenden Praktiken von Open Source und stellen einen Prototypen vor. Abschließend diskutieren wir, welche Auswirkungen die Einführung eines solchen Marktplatzes haben könnte. Translation: Marketplace to Coordinate and Finance Open Source SoftwareAbstract: The popularity of open source as a collaboration mechanism for developing software is increasing. Organizations increase their engagement. In our work, we draw the missing connection between open source projects, organizations, and markets. Without this connection, we have seen severe software vulnerability result from coordination and financing breakdowns. In this paper, we develop eight design features that a market place for open source should have to address these breakdowns. We develop the design features based on literature about the practices of open source. We present a prototype and discuss what implications would result from implementing such a market place

    High prevalence of Plasmodium falciparum gametocyte infections in school-age children using molecular detection: patterns and predictors of risk from a cross-sectional study in southern Malawi

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    Abstract Background In endemic areas, many people experience asymptomatic Plasmodium infections, particularly older children and adults, but their transmission contribution is unknown. Though not the exclusive determinant of infectiousness, transmission from humans to mosquitoes requires blood meals containing gametocytes. Gametocytes often occur at submicroscopic densities, challenging measurement in human populations. More sensitive molecular techniques allow better characterization of gametocyte epidemiologic patterns. Methods Approximately 30 households were selected from each of eight sites in southern Malawi during two cross-sectional surveys. Blood was sampled from 623 people during the dry season and 896 the following rainy season. Among people PCR-positive for Plasmodium falciparum, mature gametocytes were detected by qRT-PCR. Regression models evaluated predictors of gametocyte carriage and density in the total population and among those with PCR-positive infections. Results The prevalence of gametocyte carriage by molecular testing was 3.5% during the dry season and 8.6% during the rainy season, and by microscopy 0.8 and 3.3%, respectively. Nearly half of PCR-positive infections carried gametocytes, regardless of recent symptom status. Among P. falciparum-infected people, only living in unfinished houses and age were significantly associated with gametocyte presence. Infected people in unfinished houses had higher odds of carrying gametocytes (OR 2.24, 95% CI 1.16–4.31), and 31% (95% CI 3–65%) higher gametocyte density than those in finished houses. School-age children (5–15 years), had higher odds than adults (≥16 years) of having gametocytes when infected (OR 2.77, 95% CI 1.47–5.19), but 31% (95% CI 11–47%) lower gametocyte density. Children <5 years did not have significantly higher odds of gametocyte carriage or density when infected than adults. Conclusions School-age children frequently carry gametocytes in communities of southern Malawi and represent an under-recognized reservoir of infection. Malaria elimination strategies should address these frequently asymptomatic reservoirs, especially in highly endemic areas. Improved household construction may also reduce the infectious reservoir.http://deepblue.lib.umich.edu/bitstream/2027.42/134670/1/12936_2016_Article_1587.pd

    OPEN COMMUNITY HEALTH: WORKSHOP REPORT

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    This report summarizes key outcomes from a workshop on open community health conducted at the University of Nebraska at Omaha in April 2018. Workshop members represented research and practice communities across Citizen Science, Open Source, and Wikipedia. The outcomes from the workshop include (1) comparisons among these communities, (2) how a shared understanding and assessment of open community health can be developed, and (3) a taxonomical comparison to begin a conversation between these communities that have developed disparate languages

    Human Embryonic Stem Cells Derived by Somatic Cell Nuclear Transfer

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    SummaryReprogramming somatic cells into pluripotent embryonic stem cells (ESCs) by somatic cell nuclear transfer (SCNT) has been envisioned as an approach for generating patient-matched nuclear transfer (NT)-ESCs for studies of disease mechanisms and for developing specific therapies. Past attempts to produce human NT-ESCs have failed secondary to early embryonic arrest of SCNT embryos. Here, we identified premature exit from meiosis in human oocytes and suboptimal activation as key factors that are responsible for these outcomes. Optimized SCNT approaches designed to circumvent these limitations allowed derivation of human NT-ESCs. When applied to premium quality human oocytes, NT-ESC lines were derived from as few as two oocytes. NT-ESCs displayed normal diploid karyotypes and inherited their nuclear genome exclusively from parental somatic cells. Gene expression and differentiation profiles in human NT-ESCs were similar to embryo-derived ESCs, suggesting efficient reprogramming of somatic cells to a pluripotent state.PaperCli

    WeBo 1: A Young Barium Star Surrounded by a Ring-Like Planetary Nebula

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    WeBo 1 (PN G135.6+01.0), a previously unrecognized planetary nebula with a remarkable thin-ring morphology, was discovered serendipitously on Digitized Sky Survey images. The central star is found to be a late-type giant with overabundances of carbon and s-process elements. The giant is chromospherically active and photometrically variable, with a probable period of 4.7 days; this suggests that the star is spotted, and that 4.7 days is its rotation period. We propose a scenario in which one component of a binary system became an AGB star with a dense stellar wind enriched in C and s-process elements; a portion of the wind was accreted by the companion, contaminating its atmosphere and spinning up its rotation. The AGB star has now become a hot subdwarf, leaving the optical companion as a freshly contaminated barium star inside an ionized planetary nebula.Comment: 4 pages, 3 figures; Accepted for January 2003 issue of Astronomical Journa

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Measurement of the tt¯tt¯ production cross section in pp collisions at √s=13 TeV with the ATLAS detector

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    A measurement of four-top-quark production using proton-proton collision data at a centre-of-mass energy of 13 TeV collected by the ATLAS detector at the Large Hadron Collider corresponding to an integrated luminosity of 139 fb−1 is presented. Events are selected if they contain a single lepton (electron or muon) or an opposite-sign lepton pair, in association with multiple jets. The events are categorised according to the number of jets and how likely these are to contain b-hadrons. A multivariate technique is then used to discriminate between signal and background events. The measured four-top-quark production cross section is found to be 26+17−15 fb, with a corresponding observed (expected) significance of 1.9 (1.0) standard deviations over the background-only hypothesis. The result is combined with the previous measurement performed by the ATLAS Collaboration in the multilepton final state. The combined four-top-quark production cross section is measured to be 24+7−6 fb, with a corresponding observed (expected) signal significance of 4.7 (2.6) standard deviations over the background-only predictions. It is consistent within 2.0 standard deviations with the Standard Model expectation of 12.0 ± 2.4 fb

    Measurements of Higgs bosons decaying to bottom quarks from vector boson fusion production with the ATLAS experiment at √=13TeV

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    The paper presents a measurement of the Standard Model Higgs Boson decaying to b-quark pairs in the vector boson fusion (VBF) production mode. A sample corresponding to 126 fb−1 of s√=13TeV proton–proton collision data, collected with the ATLAS experiment at the Large Hadron Collider, is analyzed utilizing an adversarial neural network for event classification. The signal strength, defined as the ratio of the measured signal yield to that predicted by the Standard Model for VBF Higgs production, is measured to be 0.95+0.38−0.36 , corresponding to an observed (expected) significance of 2.6 (2.8) standard deviations from the background only hypothesis. The results are additionally combined with an analysis of Higgs bosons decaying to b-quarks, produced via VBF in association with a photon
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