4,516 research outputs found

    Pattern of skin disease in Ethiopian HIV‐infected patients on combination antiretroviral therapy: A cross‐sectional study in a dermatology referral hospital

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    Abstract Background More than 90% of human immunodeficiency virus (HIV)‐infected patients will develop at least one type of skin disorder during the course of the disease. The prevalence and severity of skin disease commonly seen in HIV‐infected patients has decreased in the era of combination antiretroviral therapy (cART). Few studies in Ethiopia have shown the magnitude of skin problems among adult patients on cART. The aim of this study is to describe the pattern of skin disease among adult patients who are on cART. Methods Cross‐sectional observational study at ALERT Hospital from April 2018 to November 2018. Patterns of clinically diagnosed skin diseases were summarized descriptively. Result A total of 572 patients were evaluated. In total, 412 (72%) were female and the mean age of study participants was 40 (SD = 10.4). The median CD4 count at the time of diagnosis and start of cART were 178 (R 5‐2000) and 168 cells/ÎŒl (R 5‐1327), respectively. The mean duration of cART was 8 (SD = 3) years. 89.3% of patients were on first line and 7% on second line of cART regimen. Noninfectious inflammatory skin disorders (40.9%) were the most common concomitant diagnosis followed by infectious diseases (34.9%), infestation (7.7%), pigmentary disorders (6.3%) and cutaneous drug eruption (0.7%), respectively. Among the inflammatory skin disorders, 56.5% presented with eczema. One patient had Kaposi sarcoma. Conclusion Noninfectious inflammatory skin disorders are the most common concomitant skin disease in HIV‐infected patients, with eczema being most prevalent. Infectious skin diseases were also common presentations. In our study, AIDS‐defining skin conditions were rare

    SEM and EBSD investigations of high-chromium cast irons

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    High-chromium white cast irons are alloys that are based on the iron-chromium-carbon system and are classified in ISO 21988-2006 as abrasion-resistant cast irons that contain greater than 11% chromium. High-chromium white irons are primarily used as castings and hard-facing weld deposits in equipment requiring resistance to abrasive and erosive wear under moderate impact loading conditions. These materials are used in the mining and chemical processing plants in applications such as grinding mills, slurry pumps, chute liners and pipes. The microstructures of high-chromium white irons contain a substantial proportion of chromium rich carbides that are harder than silica sand, which is a commonly encountered wear medium in mineral processing plants. High-chromium white irons are generally heat treated to develop maximum hardness via the precipitation of secondary carbides in the ferrous matrix during ageing at elevated temperatures and destabilisation of austenite, which subsequently transforms to martensite on cooling to room temperature

    A solution for estimating the tensile yield strength from small specimens

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    The small punch test is an innovative test that utilises small disc-shaped specimens to assess the mechanical behaviour of materials. The main advantage is the relatively small specimen size. In this article, a modified analytical solution for the small punch maximum bend strength is proposed that is based on classical plate theory. A clear linear relationship is observed between the tensile yield strength σYS and the small punch maximum bend strength σy for both alloys and metal matrix composites. Copyright by ASTM Int'l (all rights reserved)

    Optimal Location of Sources in Transportation Networks

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    We consider the problem of optimizing the locations of source nodes in transportation networks. A reduction of the fraction of surplus nodes induces a glassy transition. In contrast to most constraint satisfaction problems involving discrete variables, our problem involves continuous variables which lead to cavity fields in the form of functions. The one-step replica symmetry breaking (1RSB) solution involves solving a stable distribution of functionals, which is in general infeasible. In this paper, we obtain small closed sets of functional cavity fields and demonstrate how functional recursions are converted to simple recursions of probabilities, which make the 1RSB solution feasible. The physical results in the replica symmetric (RS) and the 1RSB frameworks are thus derived and the stability of the RS and 1RSB solutions are examined.Comment: 38 pages, 18 figure

    Metacognition in human decision-making: confidence and error monitoring

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    People are capable of robust evaluations of their decisions: they are often aware of their mistakes even without explicit feedback, and report levels of confidence in their decisions that correlate with objective performance. These metacognitive abilities help people to avoid making the same mistakes twice, and to avoid overcommitting time or resources to decisions that are based on unreliable evidence. In this review, we consider progress in characterizing the neural and mechanistic basis of these related aspects of metacognition—confidence judgements and error monitoring—and identify crucial points of convergence between methods and theories in the two fields. This convergence suggests that common principles govern metacognitive judgements of confidence and accuracy; in particular, a shared reliance on post-decisional processing within the systems responsible for the initial decision. However, research in both fields has focused rather narrowly on simple, discrete decisions—reflecting the correspondingly restricted focus of current models of the decision process itself—raising doubts about the degree to which discovered principles will scale up to explain metacognitive evaluation of real-world decisions and actions that are fluid, temporally extended, and embedded in the broader context of evolving behavioural goals

    Evolution of speckle during spinodal decomposition

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    Time-dependent properties of the speckled intensity patterns created by scattering coherent radiation from materials undergoing spinodal decomposition are investigated by numerical integration of the Cahn-Hilliard-Cook equation. For binary systems which obey a local conservation law, the characteristic domain size is known to grow in time τ\tau as R=[Bτ]nR = [B \tau]^n with n=1/3, where B is a constant. The intensities of individual speckles are found to be nonstationary, persistent time series. The two-time intensity covariance at wave vector k{\bf k} can be collapsed onto a scaling function Cov(ÎŽt,tˉ)Cov(\delta t,\bar{t}), where ÎŽt=k1/nBâˆŁÏ„2−τ1∣\delta t = k^{1/n} B |\tau_2-\tau_1| and tˉ=k1/nB(τ1+τ2)/2\bar{t} = k^{1/n} B (\tau_1+\tau_2)/2. Both analytically and numerically, the covariance is found to depend on ÎŽt\delta t only through ÎŽt/tˉ\delta t/\bar{t} in the small-tˉ\bar{t} limit and ÎŽt/tˉ1−n\delta t/\bar{t} ^{1-n} in the large-tˉ\bar{t} limit, consistent with a simple theory of moving interfaces that applies to any universality class described by a scalar order parameter. The speckle-intensity covariance is numerically demonstrated to be equal to the square of the two-time structure factor of the scattering material, for which an analytic scaling function is obtained for large tˉ.\bar{t}. In addition, the two-time, two-point order-parameter correlation function is found to scale as C(r/(Bnτ12n+τ22n),τ1/τ2)C(r/(B^n\sqrt{\tau_1^{2n}+\tau_2^{2n}}),\tau_1/\tau_2), even for quite large distances rr. The asymptotic power-law exponent for the autocorrelation function is found to be λ≈4.47\lambda \approx 4.47, violating an upper bound conjectured by Fisher and Huse.Comment: RevTex: 11 pages + 12 figures, submitted to PR

    Ultra-high brilliance multi-MeV Îł\gamma-ray beam from non-linear Thomson scattering

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    We report on the generation of a narrow divergence (ξ≈2.5\theta\approx 2.5 mrad), multi-MeV (EMAX=18E_\text{MAX} = 18 MeV) and ultra-high brilliance (≈2×1019\approx 2\times10^{19} photons s−1^{-1} mm−2^{-2} mrad −2^{-2} 0.1\% BW) γ\gamma-ray beam from the scattering of an ultra-relativistic laser-wakefield accelerated electron beam in the field of a relativistically intense laser (dimensionless amplitude a0≈2a_0\approx2). The spectrum of the generated γ\gamma-ray beam is measured, with MeV resolution, seamlessly from 6 MeV to 18 MeV, giving clear evidence of the onset of non-linear Thomson scattering. The photon source has the highest brilliance in the multi-MeV regime ever reported in the literature

    Non-equilibrium interface equations: An application to thermo-capillary motion in binary systems

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    Interface equations are derived for both binary diffusive and binary fluid systems subjected to non-equilibrium conditions, starting from the coarse-grained (mesoscopic) models. The equations are used to describe thermo-capillary motion of a droplet in both purely diffusive and fluid cases, and the results are compared with numerical simulations. A mesoscopic chemical potential shift, owing to the temperature gradient, and associated mesoscopic corrections involved in droplet motion are elucidated.Comment: 12 pages; Latex, revtex, ap
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