368 research outputs found

    Prevalence and aetiology of thyrotoxicosis in patients with hyperemesis gravidarum presenting to a tertiary hospital in Cape Town, South Africa

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    Background: The association between hyperemesis gravidarum (HG) and abnormal thyroid function is well known.Aims: The prevalence, aetiology and course of thyrotoxicosis in women with hyperemesis gravidarum (HG) were studied.Methods: Women admitted for HG, who underwent thyroid function evaluation between 1 August 2016 and 30 April 2019, were studied. Laboratory data included baseline human chorionic gonadotropin (hCG) and baseline (t1), discharge (t2) and follow-up (t3) thyroid function tests (thyroid stimulating hormone [TSH] and free  thyroxin [fT4]). Available TSH receptor antibody status was assessed.Results: Eighty-two patients were included. The incidence of thyrotoxicosis was 49% based on local laboratory TSH range and 48% if trimester-specific ranges used. In the majority of normal pregnancies, thyrotoxicosis was hCG-mediated (72.5%), 15% were confirmed to have Graves’ disease and 12% had a molar pregnancy. Very high fT4 levels (> 40 pmol/l) at baseline [t1] were documented in 24% of women with hCG-mediated thyrotoxicosis. Clinical features were absent in a third of women with Graves’ disease and the diagnosis was reliant on positive antibody status. Free T4 values declined from (t1) to later in gestation (t3) (p < 0.001).Conclusion: The incidence of thyrotoxicosis in women with HG is high. Free-T4 values decrease with clinical stabilisation of HG, suggesting a contribution of dehydration to the large variation in baseline fT4 measurements. Testing for TSH-receptor antibodies should be considered in women with TSH < 0.01 pmol/l and persistent fT4 elevation on follow-up. Final review of thyroid function should be performed after 15 weeks’ gestation

    Surveillance or self-surveillance? Behavioral cues can increase the rate of drivers' pro-environmental behavior at a long wait stop

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    By leaving their engines idling for long periods, drivers contribute unnecessarily to air pollution, waste fuel, and produce noise and fumes that harm the environment. Railway level crossings are sites where many cars idle, many times a day. In this research, testing two psychological theories of influence, we examine the potential to encourage drivers to switch off their ignition while waiting at rail crossings. Two field studies presented different signs at a busy rail crossing site with a 2-min average wait. Inducing public self-focus (via a “Watching Eyes” stimulus) was not effective, even when accompanied by a written behavioral instruction. Instead, cueing a private-self focus (“think of yourself”) was more effective, doubling the level of behavioral compliance. These findings confirm the need to engage the self when trying to instigate self-regulatory action, but that cues evoking self-surveillance may sometimes be more effective than cues that imply external surveillance

    Isolating Crucial Steps in Induction of Infective Endocarditis With Preclinical Modeling of Host Pathogen Interaction

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    Animal models of Staphylococcus aureus infective endocarditis (IE), especially in rodents, are commonly used to investigate the underlying pathogenesis, disease progression, potential diagnostic approaches, and therapeutic treatment. All these models are based on surgical interventions, and imply valve trauma by placing a polyurethane catheter at the aortic root. While the influence of endothelial damage and inflammation on the induction of IE has been studied intensively, the role of the catheter, as permanent source of bacteremia, and the interplay with bacterial virulence factors during the formation of IE is poorly understood. In our study, we aimed at identifying which set of preconditions is required for induction and formation of IE: (1) tissue injury, (2) permanent presence of bacteria, and (3) presence of the full bacterial repertoire of adhesion proteins. We investigated the manifestation of the disease in different modifications of the animal model, considering different degrees of endothelial damage and the presence or absence of the catheter. In four infection models the induction of IE was assessed by using two bacterial strains with different expression patterns of virulence factors – S. aureus 6850 and Newman. In vivo magnetic resonance imaging showed conspicuous morphological structures on the aortic valves, when an endothelial damage and a continuous bacterial source were present simultaneously. Cellular and inflammatory pathophysiology were characterized additionally by histology, real-time quantitative polymerase chain reaction analysis, and bacterial counts, revealing strain-specific pathogenesis and manifestation of IE, crucially influenced by bacterial adherence and toxicity. The severity of IE was dependent on the degree of endothelial irritation. However, even severe endothelial damage in the absence of a permanent bacterial source resulted in reduced valve infection. The spread of bacteria to other organs was also dependent on the pathogenic profile of the infectious agent

    The HERMES Dual-Radiator Ring Imaging Cerenkov Detector

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    The construction and use of a dual radiator Ring Imaging Cerenkov(RICH) detector is described. This instrument was developed for the HERMES experiment at DESY which emphasizes measurements of semi-inclusive deep-inelastic scattering. It provides particle identification for pions, kaons, and protons in the momentum range from 2 to 15 GeV, which is essential to these studies. The instrument uses two radiators, C4F10, a heavy fluorocarbon gas, and a wall of silica aerogel tiles. The use of aerogel in a RICH detector has only recently become possible with the development of clear, large homogeneous and hydrophobic aerogel. A lightweight mirror was constructed using a newly perfected technique to make resin-coated carbon-fiber surfaces of optical quality. The photon detector consists of 1934 photomultiplier tubes for each detector half, held in a soft steel matrix to provide shielding against the residual field of the main spectrometer magnet.Comment: 25 pages, 23 figure

    The first determination of Generalized Polarizabilities of the proton by a Virtual Compton Scattering experiment

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    Absolute differential cross sections for the reaction (e+p -> e+p+gamma) have been measured at a four-momentum transfer with virtuality Q^2=0.33 GeV^2 and polarization \epsilon = 0.62 in the range 33.6 to 111.5 MeV/c for the momentum of the outgoing photon in the photon-proton center of mass frame. The experiment has been performed with the high resolution spectrometers at the Mainz Microtron MAMI. From the photon angular distributions, two structure functions which are a linear combination of the generalized polarizabilities have been determined for the first time.Comment: 4 pages, 3 figure

    Germination capacity and seed storage behaviour of threatened metallophytes from the Katanga copper belt (D.R. Congo): Implications for ex situ conservation

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    peer reviewedBackground and aims - Plant species adapted to metalliferous soil are of high conservation value, and actions for preserving these species (some of them are endemics) are urgent given the threat of mining activities. In the framework of an integrated conservation programme of cuprophytes (plants that tolerate a soil with a high level of copper) in Katanga (D.R.Congo), this study aims at: (1) providing new data on species whose germination has never been studied so far; (2) gaining new insight into the storage behaviour of these species; (3) discussing implications for ex situ conservation of these highly threatened species. Methods - Germination tests were conducted on fresh seeds of nineteen species. These tests were repeated after 6, 12 and 24 months of storage in dry-cold conditions. Key results - Most species kept or increased their germination capacity after 2 years storage in dry-cold conditions. Nine species showed a slight decrease in their viability (from 100% to > 80%) after 2 years storage in dry-cold conditions. The present study gives evidence that at least six of the 19 studied species are desiccation-tolerant (orthodox). Among these, two are strict endemics, Haumaniastrum robertii and Faroa malaissei, and two are broad endemics, Diplolophium marthozianum and Gladiolus robiliartianus. This means that ex situ seed banking of these species could form a useful part of a more comprehensive conservation strategy. Only two species have been identifed as desiccation-sensitive (recalcitrant), i.e. inappropriate for conservation in standard seed bank conditions. An orthodox behaviour has not been ruled out for the other species tested, but their response was less clear and needs further investigation. © 2013 National Botanic Garden of Belgium and Royal Botanical Society of Belgium

    A structured approach for governing sustainable heat transitions in building renovation of towns and cities

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    This is the final version. Available on open access from IOP Publishing via the DOI in this record. Pioneer cities have demonstrated a willingness and capability to decarbonise local heat systems, but support is needed to scale up action. Heat decarbonisation is not simply a technical challenge, but also a political and social one; stakeholders must inform decisions about appropriate technological and policy solutions and will, in turn, be affected by them. Taking three dimensions of stakeholders, technology, and policy, a structured approach which centres stakeholders is presented to help local government to collaboratively find appropriate technology and policy solutions, both at the strategic scale across the municipality and in localised pilot projects, and explores how to initialise and support heat decarbonisation in more cities.European Regional Development Fund (ERDF)Province of South-Holland (Netherlands)Ministry of Economic Affairs and Climate Policy (Netherlands

    Leading order analysis of neutrino induced dimuon events in the CHORUS experiment

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    We present a leading order QCD analysis of a sample of neutrino induced charged-current events with two muons in the final state originating in the lead-scintillating fibre calorimeter of the CHORUS detector. The results are based on a sample of 8910 neutrino and 430 antineutrino induced opposite-sign dimuon events collected during the exposure of the detector to the CERN Wide Band Neutrino Beam between 1995 and 1998. % with Eμ1,Eμ2>5E_{\mu 1},E_{\mu 2} > 5 GeV and Q2>3Q^2 > 3 GeV2^2 collected %between 1995 and 1998. The analysis yields a value of the charm quark mass of \mc = (1.26\pm 0.16 \pm 0.09) \GeVcc and a value of the ratio of the strange to non-strange sea in the nucleon of κ=0.33±0.05±0.05\kappa = 0.33 \pm 0.05 \pm 0.05, improving the results obtained in similar analyses by previous experiments.Comment: Submitted to Nuclear Physics

    Associated Charm Production in Neutrino-Nucleus Interactions

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    In this paper a search for associated charm production both in neutral and charged current ν\nu-nucleus interactions is presented. The improvement of automatic scanning systems in the {CHORUS} experiment allows an efficient search to be performed in emulsion for short-lived particles. Hence a search for rare processes, like the associated charm production, becomes possible through the observation of the double charm-decay topology with a very low background. About 130,000 ν\nu interactions located in the emulsion target have been analysed. Three events with two charm decays have been observed in the neutral-current sample with an estimated background of 0.18±\pm0.05. The relative rate of the associated charm cross-section in deep inelastic ν\nu interactions, σ(ccˉν)/σNCDIS=(3.622.42+2.95(stat)±0.54(syst))×103\sigma(c\bar{c}\nu)/\sigma_\mathrm{NC}^\mathrm{DIS}= (3.62^{+2.95}_{-2.42}({stat})\pm 0.54({syst}))\times 10^{-3} has been measured. One event with two charm decays has been observed in charged-current νμ\nu_\mu interactions with an estimated background of 0.18±\pm0.06 and the upper limit on associated charm production in charged-current interactions at 90% C.L. has been found to be σ(ccˉμ)/σCC<9.69×104\sigma (c\bar{c} \mu^-)/\sigma_\mathrm{CC} < 9.69 \times 10^{-4}.Comment: 10 pages, 4 figure

    Charged-Particle Multiplicities in Charged-Current Neutrino-- and Anti-Neutrino--Nucleus Interactions

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    The CHORUS experiment, designed to search for νμντ\nu_{\mu}\to\nu_{\tau} oscillations, consists of a nuclear emulsion target and electronic detectors. In this paper, results on the production of charged particles in a small sample of charged-current neutrino-- and anti-neutrino--nucleus interactions at high energy are presented. For each event, the emission angle and the ionization features of the charged particles produced in the interaction are recorded, while the standard kinematic variables are reconstructed using the electronic detectors. The average multiplicities for charged tracks, the pseudo-rapidity distributions, the dispersion in the multiplicity of charged particles and the KNO scaling are studied in different kinematical regions. A study of quasi-elastic topologies performed for the first time in nuclear emulsions is also reported. The results are presented in a form suitable for use in the validation of Monte Carlo generators of neutrino--nucleus interactions.Comment: 17 pages, 5 figure
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