353 research outputs found

    Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

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    Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

    Human matrix metalloproteinases: An ubiquitarian class of enzymes involved in several pathological processes

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    Human matrix metalloproteinases (MMPs) belong to the M10 family of the MA clan of endopeptidases. They are ubiquitarian enzymes, structurally characterized by an active site where a Zn(2+) atom, coordinated by three histidines, plays the catalytic role, assisted by a glutamic acid as a general base. Various MMPs display different domain composition, which is very important for macromolecular substrates recognition. Substrate specificity is very different among MMPs, being often associated to their cellular compartmentalization and/or cellular type where they are expressed. An extensive review of the different MMPs structural and functional features is integrated with their pathological role in several types of diseases, spanning from cancer to cardiovascular diseases and to neurodegeneration. It emerges a very complex and crucial role played by these enzymes in many physiological and pathological processes

    Midwives Understanding of Physical Activity Guidelines During Pregnancy

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    Objective to examine the current level of understanding held by midwives regarding the NICE physical activity guidelines in the UK, and to investigate the physical activity guidance given to women during pregnancy. Design an 11 question online survey comprising of a mixture of closed and open ended questions. Setting data reflects participants sampled across the United Kingdom. Participants fifty-nine midwives completed the online survey Measurements and findings an electronic survey was used to explore the midwives understanding of physical activity guidelines during pregnancy, and the advice they offered to women in their care. Qualitative content analysis was used to gain a more in-depth understanding of midwife knowledge. Two per cent of midwives correctly identified the physical activity guidelines, with 44 giving partially correct responses, 25 giving incorrect responses and 29 unsure of what the guidelines are. Despite the low level of correct responses, 59 of respondents reported they were confident or very confident in answering questions regarding physical activity. Only 4 of respondents reported having access to continual professional development (CPD) in the area of PA guidance. Key conclusions there appears to be a misplaced confidence amongst midwives in their knowledge of the NICE PA guidelines for pregnancy. Implications for practice as physical inactivity can be detrimental for the health of both mother and baby, there is a clear need for better dissemination of the current and future NICE physical activity guidelines in primary health care settings. The current study determined a substantial lack of CPD in the area of PA guidance, which may be a contributing factor to the lack of knowledge of the guidelines. As such, increasing CPD may in turn improve the accuracy of the advice given to pregnant women and consequently benefit the health of both mother and baby. © 2018 Elsevier Lt

    Accelerated Charged Particle Tracking with Graph Neural Networks on FPGAs

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    We develop and study FPGA implementations of algorithms for charged particle tracking based on graph neural networks. The two complementary FPGA designs are based on OpenCL, a framework for writing programs that execute across heterogeneous platforms, and hls4ml, a high-level-synthesis-based compiler for neural network to firmware conversion. We evaluate and compare the resource usage, latency, and tracking performance of our implementations based on a benchmark dataset. We find a considerable speedup over CPU-based execution is possible, potentially enabling such algorithms to be used effectively in future computing workflows and the FPGA-based Level-1 trigger at the CERN Large Hadron Collider.Comment: 8 pages, 4 figures, To appear in Third Workshop on Machine Learning and the Physical Sciences (NeurIPS 2020

    Physics and Computing Performance of the Exa.TrkX TrackML Pipeline

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    The Exa.TrkX project has applied geometric learning concepts such as metric learning and graph neural networks to HEP particle tracking. The Exa.TrkX tracking pipeline clusters detector measurements to form track candidates and filters them. The pipeline, originally developed using the TrackML dataset (a simulation of an LHC-like tracking detector), has been demonstrated on various detectors, including the DUNE LArTPC and the CMS High-Granularity Calorimeter. This paper documents new developments needed to study the physics and computing performance of the Exa.TrkX pipeline on the full TrackML dataset, a first step towards validating the pipeline using ATLAS and CMS data. The pipeline achieves tracking efficiency and purity similar to production tracking algorithms. Crucially for future HEP applications, the pipeline benefits significantly from GPU acceleration, and its computational requirements scale close to linearly with the number of particles in the event

    Flow and geochemistry of groundwater beneath a back-barrier lagoon : the subterranean estuary at Chincoteague Bay, Maryland, USA

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    This paper is not subject to U.S. copyright. The definitive version was published in Marine Chemistry 113 (2009): 78-92, doi:10.1016/j.marchem.2009.01.004.To better understand large-scale interactions between fresh and saline groundwater beneath an Atlantic coastal estuary, an offshore drilling and sampling study was performed in a large barrier-bounded lagoon, Chincoteague Bay, Maryland, USA. Groundwater that was significantly fresher than overlying bay water was found in shallow plumes up to 8 m thick extending more than 1700 m offshore. Groundwater saltier than bay surface water was found locally beneath the lagoon and the barrier island, indicating recharge by saline water concentrated by evaporation prior to infiltration. Steep salinity and nutrient gradients occur within a few meters of the sediment surface in most locations studied, with buried peats and estuarine muds acting as confining units. Groundwater ages were generally more than 50 years in both fresh and brackish waters as deep as 23 m below the bay bottom. Water chemistry and isotopic data indicate that freshened plumes beneath the estuary are mixtures of water originally recharged on land and varying amounts of estuarine surface water that circulated through the bay floor, possibly at some distance from the sampling location. Ammonium is the dominant fixed nitrogen species in saline groundwater beneath the estuary at the locations sampled. Isotopic and dissolved-gas data from one location indicate that denitrification within the subsurface flow system removed terrestrial nitrate from fresh groundwater prior to discharge along the western side of the estuary. Similar situations, with one or more shallow semi-confined flow systems where groundwater geochemistry is strongly influenced by circulation of surface estuary water through organic-rich sediments, may be common on the Atlantic margin and elsewhere.Primary funding was provided by USGS (Coastal and Marine Geology Program and National Research Program in Water Resources) with additional material support from the National Park Service (C. Zimmerman) and the University of Toledo

    Features of Acute COVID-19 Associated With Post-acute Sequelae of SARS-CoV-2 Phenotypes: Results From the IMPACC Study

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    Post-acute sequelae of SARS-CoV-2 (PASC) is a significant public health concern. We describe Patient Reported Outcomes (PROs) on 590 participants prospectively assessed from hospital admission for COVID-19 through one year after discharge. Modeling identified 4 PRO clusters based on reported deficits (minimal, physical, mental/cognitive, and multidomain), supporting heterogenous clinical presentations in PASC, with sub-phenotypes associated with female sex and distinctive comorbidities. During the acute phase of disease, a higher respiratory SARS-CoV-2 viral burden and lower Receptor Binding Domain and Spike antibody titers were associated with both the physical predominant and the multidomain deficit clusters. A lower frequency of circulating B lymphocytes by mass cytometry (CyTOF) was observed in the multidomain deficit cluster. Circulating fibroblast growth factor 21 (FGF21) was significantly elevated in the mental/cognitive predominant and the multidomain clusters. Future efforts to link PASC to acute anti-viral host responses may help to better target treatment and prevention of PASC
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