2,714 research outputs found

    Prevalence of tuberculosis in post-mortem studies of HIV-infected adults and children in resource-limited settings: a systematic review and meta-analysis.

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    OBJECTIVES: Tuberculosis (TB) is estimated to be the leading cause of HIV-related deaths globally. However, since HIV-associated TB frequently remains unascertained, we systematically reviewed autopsy studies to determine the true burden of TB at death. METHODS: We systematically searched Medline and Embase databases (to end 2013) for literature reporting on health facility-based autopsy studies of HIV-infected adults and/or children in resource-limited settings. Using forest plots and random-effects meta-analysis, we summarized the TB prevalence found at autopsy and used meta-regression to explore variables associated with autopsy TB prevalence. RESULTS: We included 36 eligible studies, reporting on 3237 autopsies. Autopsy TB prevalence was extremely heterogeneous (range 0-64.4%), but was markedly higher in adults [pooled prevalence 39.7%, 95% confidence interval (CI) 32.4-47.0%] compared to children (pooled prevalence 4.5%, 95% CI 1.7-7.4%). Post-mortem TB prevalence varied by world region, with pooled estimates in adults of 63.2% (95% CI 57.7-68.7%) in South Asia (n = 2 studies); 43.2% (95% CI 38.0-48.3) in sub-Saharan Africa (n = 9 studies); and 27.1% (95% CI 16.0-38.1%) in the Americas (n = 5 studies). Autopsy prevalence positively correlated with contemporary estimates of national TB prevalence. TB in adults was disseminated in 87.9% (82.2-93.7%) of cases and was considered the cause of death in 91.4% (95% CI 85.8-97.0%) of TB cases. Overall, TB was the cause of death in 37.2% (95% CI 25.7-48.7%) of adult HIV/AIDS-related deaths. TB remained undiagnosed at death in 45.8% (95% CI 32.6-59.1%) of TB cases. CONCLUSIONS: In resource-limited settings, TB accounts for approximately 40% of facility-based HIV/AIDS-related adult deaths. Almost half of this disease remains undiagnosed at the time of death. These findings highlight the critical need to improve the prevention, diagnosis and treatment of HIV-associated TB globally

    Universal Critical Exponents of the Magnetic Domain Wall Depinning Transition

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    Magnetic field driven domain wall dynamics in a ferrimagnetic GdFeCo thin film with perpendicular magnetic anisotropy is studied using low temperature magneto-optical Kerr microscopy. Measurements performed in a practically athermal condition allow for the direct experimental determination of the velocity (β=0.30±0.03 \beta = 0.30 \pm 0.03 ) and correlation length (ν=1.3±0.3 \nu = 1.3 \pm 0.3 ) exponents of the depinning transition. The whole family of exponents characterizing the transition is deduced, providing evidence that the depinning of magnetic domain walls is better described by the quenched Edwards-Wilkinson universality class.Comment: 6 pages, 3 figures. Ancillary Material with 10 pages and 4 figures is also include

    The Circumstellar Disk of the Butterfly Star in Taurus

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    We present a model of the circumstellar environment of the so-called ``Butterfly Star'' in Taurus (IRAS 04302+2247). The appearance of this young stellar object is dominated by a large circumstellar disk seen edge-on and the light scattering lobes above the disk. The model is based on multi-wavelength continuum observations: Millimeter maps and high-resolution near-infrared images obtained with HST/NICMOS. It was found that the disk and envelope parameters are comparable with those of the circumstellar environment of other young stellar objects. A main result is that the dust properties must be different in the circumstellar disk and in the envelope: While a grain size distribution with grain radii up to 100 micron is required to reproduce the millimeter observations of the disk, the envelope is dominated by smaller grains similar to those of the interstellar medium. Preprint with high figure quality available at: http://spider.ipac.caltech.edu/staff/swolf/homepage/public/preprints/i04302.psComment: 32 pages, 9 figure

    Case Report Fatal Lactic Acidosis in a Kidney Transplant Recipient on Combination Antiretroviral Therapy after Initiation of Tacrolimus Therapy

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    In general, kidney transplantation is safe and efficacious in patients receiving treatment for HIV. Although multiple drug interactions between antiviral and immunosuppressive treatments exist, few patients experience serious adverse reactions. We report a case of fatal lactic acidosis in a healthy kidney transplant recipient with stable HIV infection who had previously received treatment for and cleared hepatitis C virus infection. Death occurred less than one month following the initiation of tacrolimus therapy. Based on predicted drug interactions, appropriate tacrolimus dosing was calculated prior to its commencement, yet plasma tacrolimus levels were initially unexpectedly high. The patient subsequently developed lactic acidosis and hepatic steatosis, presumably due to mitochondrial toxicity from the antiretroviral regimen on which he had previously been stable. We suspect CYP2C19 * 2 (poor metaboliser) genotype status and concomitant treatment with lansoprazole, tacrolimus, and antiretroviral (ARV) medications resulted in hepatic decompensation. This highlights the importance of careful interaction screening for all new drugs administered to patients with HIV who have complex treatment regimens as well as heightened clinical vigilance for unexpected toxicities

    Relativistic MHD and black hole excision: Formulation and initial tests

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    A new algorithm for solving the general relativistic MHD equations is described in this paper. We design our scheme to incorporate black hole excision with smooth boundaries, and to simplify solving the combined Einstein and MHD equations with AMR. The fluid equations are solved using a finite difference Convex ENO method. Excision is implemented using overlapping grids. Elliptic and hyperbolic divergence cleaning techniques allow for maximum flexibility in choosing coordinate systems, and we compare both methods for a standard problem. Numerical results of standard test problems are presented in two-dimensional flat space using excision, overlapping grids, and elliptic and hyperbolic divergence cleaning.Comment: 22 pages, 8 figure

    Perceptions of the targets and sources of COVID-19 threat are structured by group memberships and responses are influenced by identification with humankind

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    This research was supported by a grant from the German Research Foundation awarded to RvD, NMJ, and JAH (DI 848/15-1 and HA 6455/4-1). Data collection for this study was supported by a grant from the association of friends and supporters (Freunde & Förderer) at Goethe University.The purpose of this study was to investigate which social groups are perceived as a threat target and which are perceived as a threat source during the COVID-19 outbreak. In a German sample (N = 1454) we examined perceptions of social groups ranging from those that are psychologically close and smaller (family, friends, neighbors) to those that are more distal and larger (people living in Germany, humankind). We hypothesized that psychologically closer groups would be perceived as less affected by COVID-19 as well as less threatening than more psychologically distal groups. Based on social identity theorizing, we also hypothesized that stronger identification with humankind would change these patterns. Furthermore, we explored how these threat perceptions relate to adherence to COVID-19 health guidelines. In line with our hypotheses, latent random-slope modelling revealed that psychologically distal and larger groups were perceived as more affected by COVID-19 and as more threatening than psychologically closer and smaller groups. Including identification with humankind as a predictor into the threat target model resulted in a steeper increase in threat target perception patterns, whereas identification with humankind did not predict differences in threat source perceptions. Additionally, an increase in threat source perceptions across social groups was associated with more adherence to health guidelines, whereas an increase in threat target perceptions was not. We fully replicated these findings in a subgroup from the original sample (N = 989) four weeks later. We argue that societal recovery from this and other crises will be supported by an inclusive approach informed by a sense of our common identity as human beings.Publisher PDFPeer reviewe

    How national leaders keep ‘us’ safe : a longitudinal, four-nation study exploring the role of identity leadership as a predictor of adherence to COVID-19 non-pharmaceutical interventions

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    This research was supported by a grant from the German Research Foundation awarded to RvD, NMJ and JAH (DI 848/15-1 and HA 6455/4-1).Objectives : To investigate whether citizens’ adherence to health-protective non-pharmaceutical interventions (NPIs) during the COVID-19 pandemic is predicted by identity leadership, wherein leaders are perceived to create a sense of shared national identity. Design : Observational two-wave study. Hypotheses testing was conducted with structural equation modelling. Setting : Data collection during the COVID-19 pandemic in China, Germany, Israel and the USA in April/May 2020 and four weeks later. Participants : Adults in China (n=548, 66.6% women), Germany (n=182, 78% women), Israel (n=198, 51.0% women) and the USA (n=108, 58.3% women). Measures : Identity leadership (assessed by the four-item Identity Leadership Inventory Short-Form) at Time 1, perceived shared national identification (PSNI; assessed with four items) and adherence to health-protective NPIs (assessed with 10 items that describe different health-protective interventions; for example, wearing face masks) at Time 2. Results : Identity leadership was positively associated with PSNI (95% CI 0.11 to 0.30, p<0.001) in all countries. This, in turn, was related to more adherence to health-protective NPIs in all countries (95% CI 0.03 to 0.36, 0.001≤p≤0.017) except Israel (95% CI −0.03 to 0.27, p=0.119). In Germany, the more people saw Chancellor Merkel as engaging in identity leadership, the more they adhered to health-protective NPIs (95% CI 0.04 to 0.18, p=0.002). In the USA, in contrast, the more people perceived President Trump as engaging in identity leadership, the less they adhered to health-protective NPIs (95% CI −0.17 to −0.04, p=0.002). Conclusions : National leaders can make a difference by promoting a sense of shared identity among their citizens because people are more inclined to follow health-protective NPIs to the extent that they feel part of a united ‘us’. However, the content of identity leadership (perceptions of what it means to be a nation’s citizen) is essential, because this can also encourage people to disregard such recommendations.Publisher PDFPeer reviewe
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