1,023 research outputs found

    Hydrodynamic limit of gradient exclusion processes with conductances

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    Fix a strictly increasing right continuous with left limits function W: \bb R \to \bb R and a smooth function \Phi : [l,r] \to \bb R, defined on some interval [l,r][l,r] of \bb R, such that 0<b≀Ίâ€Č≀b−10<b \le \Phi'\le b^{-1}. We prove that the evolution, on the diffusive scale, of the empirical density of exclusion processes, with conductances given by WW, is described by the weak solutions of the non-linear differential equation ∂tρ=(d/dx)(d/dW)Ί(ρ)\partial_t \rho = (d/dx)(d/dW) \Phi(\rho). We derive some properties of the operator (d/dx)(d/dW)(d/dx)(d/dW) and prove uniqueness of weak solutions of the previous non-linear differential equation

    Insomnia as an Independent Predictor of Incident Cardiovascular Disease in HIV: Data from the Veterans Aging Cohort Study

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    Background: Insomnia is associated with increased cardiovascular disease (CVD) risk in the general population and is highly prevalent in people with HIV. The CVD risk conferred by insomnia in the HIV population is unknown. Methods: Using the Veterans Aging Cohort Study-Survey Cohort, insomnia symptoms were measured and dummy coded with the item, “Difficulty falling or staying asleep?” (5-point scale from no difficulty to bothers a lot). Incident CVD event ICD-9 codes (acute myocardial infarction, stroke, or coronary artery revascularization) were identified with VA and Medicare administrative data and VA fee-for-service data. Those with baseline CVD were excluded. Results: HIV-infected (N=3,108) veterans had a median follow-up time of 10.8 years, during which 267 CVD events occurred. Compared to HIV-infected veterans with no difficulty falling or staying asleep, HIV-infected veterans bothered a lot by insomnia symptoms had an increased risk of incident CVD after adjusting for demographics (HR=1.64, 95%CI=1.16-2.31, p=.005), CVD risk factors (HR=1.62, 95%CI=1.14-2.30, p=.007), additional potential confounders (hepatitis C infection, renal disease, anemia, alcohol use, cocaine use; HR=1.70, 95%CI=1.19-2.43, p=.003), and HIV-specific factors (HIV-1 RNA, CD4+ T-cell count, ART; HR=1.66, 95%CI=1.16-2.37, p=.005). Additional adjustment for non-benzodiazepine sleep medication (HR=1.62, 95%CI=1.13-2.32, p=.009) did not attenuate the association; however, it fell short of significance at p < .01 after adjustment for depressive symptoms (HR=1.51, 95%CI=0.98-2.32, p=.060) or antidepressant medication (HR=1.51, 95%CI=1.04-2.19, p=.031). Conclusion: Highly bothersome insomnia symptoms were significantly associated with incident CVD in HIV-infected veterans, suggesting that insomnia may be a novel, modifiable risk factor for CVD in HIV

    Inclusive School Community: Why is it so Complex?

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    This paper addresses the question: why is it so hard for school communities to respond to diversity in learners, staff and parents in inclusive ways? The authors draw on theory and recent professional experience in Queensland, Australia, to offer four guiding principles that address traditional assumptions about learning that result in inequality of opportunity and outcomes for students. The authors suggest these principles to support the development of a more inclusive school community: (1) develop a learning community incorporating a critical friend; (2) value and collaborate with parents and the broader community; (3) engage students as citizens in school review and develop¬ment; and (4) support teachers’ critical engagement with inclusive ideals and practices. The authors describe how the principles can work in concert in a school community

    Proteomic analysis at the sites of clinical infection with invasive Streptococcus pyogenes

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    Invasive Streptococcus pyogenes infections are rare, with often-unexplained severity. Prompt diagnosis is desirable, as deaths can occur rapidly following onset and there is an increased, but preventable, risk to contacts. Here, proteomic analyses of clinical samples from invasive human S. pyogenes infections were undertaken to determine if novel diagnostic targets could be detected, and to augment our understanding of disease pathogenesis. Fluid samples from 17 patients with confirmed invasive S. pyogenes infection (empyema, septic arthritis, necrotising fasciitis) were analysed by proteomics for streptococcal and human proteins; 16/17 samples had detectable S. pyogenes DNA. Nineteen unique S. pyogenes proteins were identified in just 6/17 samples, and 15 of these were found in a single pleural fluid sample including streptococcal inhibitor of complement, trigger factor, and phosphoglycerate kinase. In contrast, 469 human proteins were detected in patient fluids, 177 (38%) of which could be identified as neutrophil proteins, including alpha enolase and lactotransferrin which, together, were found in all 17 samples. Our data suggest that streptococcal proteins are difficult to detect in infected fluid samples. A vast array of human proteins associated with leukocyte activity are, however, present in samples that deserve further evaluation as potential biomarkers of infection

    Occupation time of exclusion processes with conductances

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    Em publicação em "Journal of statistical physics". ISSN 0022-4715.We obtain the fluctuations for the occupation time of one-dimensional symmetric exclusion processes with speed change, where the transition rates ({\em conductances}) are driven by a general function WW. The approach does not require sharp bounds on the spectral gap of the system nor the jump rates to be bounded from above or below. We present some examples and for one of them, we observe that the fluctuations of the current are trivial, but the fluctuations of the occupation time are given by a fractional Brownian Motion. This shows that, in general, the fluctuations of the current and of the occupation time are not of same order.CAPESFundação para a CiĂȘncia e a Tecnologia (FCT)CNP

    Association Between Depressive Disorders and Incident Acute Myocardial Infarction in Human Immunodeficiency Virus–Infected Adults

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    IMPORTANCE With the advent of highly effective antiretroviral therapy and improved survival, human immunodeficiency virus (HIV)–infected people are living longer and are now at an increased risk for cardiovascular disease (CVD). There is an urgent need to identify novel risk factors and primary prevention approaches for CVD in HIV. Although depression is prevalent in HIV-infected adults and is associated with future CVD in the general population, its association with CVD events has not been examined in the HIV-infected population. OBJECTIVE To examine whether depressive disorders are prospectively associated with incident acute myocardial infarction (AMI) in a large cohort of adults with HIV. DESIGN, SETTING, AND PARTICIPANTS Included in this cohort study were 26 144 HIV-infected veterans without CVD at baseline (1998–2003) participating in the US Department of Veterans Affairs Veterans Aging Cohort Study from April 1, 2003, through December 31, 2009. At baseline, 4853 veterans (19%) with major depressive disorder (MDD; International Classification of Diseases, Ninth Revision [ICD-9] codes 296.2 and 296.3) and 2296 (9%) with dysthymic disorder (ICD-9 code 300.4) were identified. The current analysis was conducted from January 2015 to November 2015. MAIN OUTCOMES AND MEASURES Incident AMI (defined by discharge summary documentation, enzyme/electrocardiography evidence of AMI, inpatient ICD-9 code for AMI (410), or AMI as underlying cause of death [International Statistical Classification of Diseases and Related Health Problems, Tenth Revision code 121]) between the enrollment date and December 31, 2009. RESULTS The mean (SD) age of those with MDD was 47.3 (7.9) years and for those without MDD was 48.2 (9.7) years. During 5.8 years of follow-up, 490 AMI events (1.9%) occurred. Baseline MDD was associated with incident AMI after adjusting for demographics (hazard ratio [HR], 1.31; 95% CI, 1.05–1.62), CVD risk factors (HR, 1.29; 95% CI, 1.04–1.60), and HIV-specific factors (HR, 1.30; 95% CI, 1.05–1.62). Further adjustment for hepatitis C, renal disease, substance abuse, and hemoglobin level (HR, 1.25; 95% CI, 1.00–1.56) and antidepressant use (HR, 1.12; 95% CI, 0.87–1.42) attenuated associations. Baseline dysthymic disorder was not associated with incident AMI. CONCLUSIONS AND RELEVANCE We report novel evidence that HIV-infected adults with MDD have a 30% increased risk for AMI than HIV-infected adults without MDD after adjustment for many potential confounders. Our findings raise the possibility that MDD may be independently associated with incident atherosclerotic CVD in the HIV-infected population

    Don't Stop Thinking About Leptoquarks: Constructing New Models

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    We discuss the general framework for the construction of new models containing a single, fermion number zero scalar leptoquark of mass ≃200−220\simeq 200-220 GeV which can both satisfy the D0/CDF search constraints as well as low energy data, and can lead to both neutral and charged current-like final states at HERA. The class of models of this kind necessarily contain new vector-like fermions with masses at the TeV scale which mix with those of the Standard Model after symmetry breaking. In this paper we classify all models of this type and examine their phenomenological implications as well as their potential embedding into SUSY and non-SUSY GUT scenarios. The general coupling parameter space allowed by low energy as well as collider data for these models is described and requires no fine-tuning of the parameters.Comment: Modified text, added table, and updated reference

    Design and testing of hydrophobic core/hydrophilic shell nano/micro particles for drug-eluting stent coating

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    In this study, we designed a novel drug-eluting coating for vascular implants consisting of a core coating of the anti-proliferative drug docetaxel (DTX) and a shell coating of the platelet glycoprotein IIb/IIIa receptor monoclonal antibody SZ-21. The core/shell structure was sprayed onto the surface of 316L stainless steel stents using a coaxial electrospray process with the aim of creating a coating that exhibited a differential release of the two drugs. The prepared stents displayed a uniform coating consisting of nano/micro particles. In vitro drug release experiments were performed, and we demonstrated that a biphasic mathematical model was capable of capturing the data, indicating that the release of the two drugs conformed to a diffusion-controlled release system. We demonstrated that our coating was capable of inhibiting the adhesion and activation of platelets, as well as the proliferation and migration of smooth muscle cells (SMCs), indicating its good biocompatibility and anti-proliferation qualities. In an in vivo porcine coronary artery model, the SZ-21/DTX drug-loaded hydrophobic core/hydrophilic shell particle coating stents were observed to promote re-endothelialization and inhibit neointimal hyperplasia. This core/shell particle-coated stent may serve as part of a new strategy for the differential release of different functional drugs to sequentially target thrombosis and in-stent restenosis during the vascular repair process and ensure rapid re-endothelialization in the field of cardiovascular disease

    The clinical features of the piriformis syndrome: a systematic review

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    Piriformis syndrome, sciatica caused by compression of the sciatic nerve by the piriformis muscle, has been described for over 70 years; yet, it remains controversial. The literature consists mainly of case series and narrative reviews. The objectives of the study were: first, to make the best use of existing evidence to estimate the frequencies of clinical features in patients reported to have PS; second, to identify future research questions. A systematic review was conducted of any study type that reported extractable data relevant to diagnosis. The search included all studies up to 1 March 2008 in four databases: AMED, CINAHL, Embase and Medline. Screening, data extraction and analysis were all performed independently by two reviewers. A total of 55 studies were included: 51 individual and 3 aggregated data studies, and 1 combined study. The most common features found were: buttock pain, external tenderness over the greater sciatic notch, aggravation of the pain through sitting and augmentation of the pain with manoeuvres that increase piriformis muscle tension. Future research could start with comparing the frequencies of these features in sciatica patients with and without disc herniation or spinal stenosis
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