79 research outputs found

    Classifying perinatal mortality using verbal autopsy: is there a role for nonphysicians?

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    <p>Abstract</p> <p>Background</p> <p>Because of a physician shortage in many low-income countries, the use of nonphysicians to classify perinatal mortality (stillbirth and early neonatal death) using verbal autopsy could be useful.</p> <p>Objective</p> <p>To determine the extent to which underlying perinatal causes of deaths assigned by nonphysicians in Guatemala, Pakistan, Zambia, and the Democratic Republic of the Congo using a verbal autopsy method are concordant with underlying perinatal cause of death assigned by physician panels.</p> <p>Methods</p> <p>Using a train-the-trainer model, 13 physicians and 40 nonphysicians were trained to determine cause of death using a standardized verbal autopsy training program. Subsequently, panels of two physicians and individual nonphysicians from this trained cohort independently reviewed verbal autopsy data from a sample of 118 early neonatal deaths and 134 stillbirths. With the cause of death assigned by the physician panel as the reference standard, sensitivity, specificity, positive and negative predictive values, and cause-specific mortality fractions were calculated to assess nonphysicians' coding responses. Robustness criteria to assess how well nonphysicians performed were used.</p> <p>Results</p> <p>Causes of early neonatal death and stillbirth assigned by nonphysicians were concordant with physician-assigned causes 47% and 57% of the time, respectively. Tetanus filled robustness criteria for early neonatal death, and cord prolapse filled robustness criteria for stillbirth.</p> <p>Conclusions</p> <p>There are significant differences in underlying cause of death as determined by physicians and nonphysicians even when they receive similar training in cause of death determination. Currently, it does not appear that nonphysicians can be used reliably to assign underlying cause of perinatal death using verbal autopsy.</p

    Coherent elastic neutrino-nucleus scattering: Terrestrial and astrophysical applications

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    Coherent elastic neutrino-nucleus scattering (CEν\nuNS) is a process in which neutrinos scatter on a nucleus which acts as a single particle. Though the total cross section is large by neutrino standards, CEν\nuNS has long proven difficult to detect, since the deposited energy into the nucleus is \sim keV. In 2017, the COHERENT collaboration announced the detection of CEν\nuNS using a stopped-pion source with CsI detectors, followed up the detection of CEν\nuNS using an Ar target. The detection of CEν\nuNS has spawned a flurry of activities in high-energy physics, inspiring new constraints on beyond the Standard Model (BSM) physics, and new experimental methods. The CEν\nuNS process has important implications for not only high-energy physics, but also astrophysics, nuclear physics, and beyond. This whitepaper discusses the scientific importance of CEν\nuNS, highlighting how present experiments such as COHERENT are informing theory, and also how future experiments will provide a wealth of information across the aforementioned fields of physics

    Coherent elastic neutrino-nucleus scattering: Terrestrial and astrophysical applications

    Get PDF
    Coherent elastic neutrino-nucleus scattering (CEν\nuNS) is a process inwhich neutrinos scatter on a nucleus which acts as a single particle. Thoughthe total cross section is large by neutrino standards, CEν\nuNS has longproven difficult to detect, since the deposited energy into the nucleus is\sim keV. In 2017, the COHERENT collaboration announced the detection ofCEν\nuNS using a stopped-pion source with CsI detectors, followed up thedetection of CEν\nuNS using an Ar target. The detection of CEν\nuNS hasspawned a flurry of activities in high-energy physics, inspiring newconstraints on beyond the Standard Model (BSM) physics, and new experimentalmethods. The CEν\nuNS process has important implications for not onlyhigh-energy physics, but also astrophysics, nuclear physics, and beyond. Thiswhitepaper discusses the scientific importance of CEν\nuNS, highlighting howpresent experiments such as COHERENT are informing theory, and also how futureexperiments will provide a wealth of information across the aforementionedfields of physics.<br

    The Economic Gains to Colorado of Amendment 66

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    Design and generation of a recombinant hepatitis B-based viral vector system for use in cellular receptor studies

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    grantor: University of TorontoThe hepatitis B virus remains a prevalent global problem despite the availability of recombinant vaccines. One of the greatest challenges facing hepatitis B researchers is the unavailability of an in vitro hepatitis B virus replication system. As a result, initial viral entry steps as well as the cellular receptor for HBV remain undefined. In this study, construction and generation of recombinant hepatitis B viral particles carrying a reporter gene has been attempted. Different immortalized cell lines were tested for their ability to drive hepatitis B promoters. The enhanced green fluorescent protein (EGFP) was placed under control of the different hepatitis B promoter regions and transfected into Chang Liver, Chinese Hamster Ovary (CHO), HeLa, Hepatoblastoma G2 (Hep G2), Human Hepatoma 7 (HuH-7), Ost-7, and Sf9 cells. Only Hep G2 and HuH-7 cells were capable of driving EGFP expression under all HBV promoters. Recombinant baculoviruses carrying replication-defective HBV genomes and HBV packaging genes were generated to deliver HBV DNA into Hep G2 and HuH-7 cells. The ability of these cell lines to secrete replication-defective HBV particles was confirmed using specific PCR reactions and electron microscopy. Further development of this viral system would eventually provide us a useful tool to help elucidate the early stages of the hepatitis B virus replication cycle. This, in turn, will further the development of drugs and therapies for those infected with the hepatitis B virus.M.Sc
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