1,229 research outputs found

    Single Cell Analysis of Lymph Node Tissue from HIV-1 Infected Patients Reveals that the Majority of CD4<sup>+</sup> T-cells Contain One HIV-1 DNA Molecule

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    Genetic recombination contributes to the diversity of human immunodeficiency virus (HIV-1). Productive HIV-1 recombination is, however, dependent on both the number of HIV-1 genomes per infected cell and the genetic relationship between these viral genomes. A detailed analysis of the number of proviruses and their genetic relationship in infected cells isolated from peripheral blood and tissue compartments is therefore important for understanding HIV-1 recombination, genetic diversity and the dynamics of HIV-1 infection. To address these issues, we used a previously developed single-cell sequencing technique to quantify and genetically characterize individual HIV-1 DNA molecules from single cells in lymph node tissue and peripheral blood. Analysis of memory and naïve CD4+ T cells from paired lymph node and peripheral blood samples from five untreated chronically infected patients revealed that the majority of these HIV-1-infected cells (>90%) contain only one copy of HIV-1 DNA, implying a limited potential for productive recombination in virus produced by these cells in these two compartments. Phylogenetic analysis revealed genetic similarity of HIV-1 DNA in memory and naïve CD4+ T-cells from lymph node, peripheral blood and HIV-1 RNA from plasma, implying exchange of virus and/or infected cells between these compartments in untreated chronic infection

    A straightforward multiallelic significance test for the Hardy-Weinberg equilibrium law

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    Much forensic inference based upon DNA evidence is made assuming Hardy-Weinberg Equilibrium (HWE) for the genetic loci being used. Several statistical tests to detect and measure deviation from HWE have been devised, and their limitations become more obvious when testing for deviation within multiallelic DNA loci. The most popular methods-Chi-square and Likelihood-ratio tests-are based on asymptotic results and cannot guarantee a good performance in the presence of low frequency genotypes. Since the parameter space dimension increases at a quadratic rate on the number of alleles, some authors suggest applying sequential methods, where the multiallelic case is reformulated as a sequence of “biallelic” tests. However, in this approach it is not obvious how to assess the general evidence of the original hypothesis; nor is it clear how to establish the significance level for its acceptance/rejection. In this work, we introduce a straightforward method for the multiallelic HWE test, which overcomes the aforementioned issues of sequential methods. The core theory for the proposed method is given by the Full Bayesian Significance Test (FBST), an intuitive Bayesian approach which does not assign positive probabilities to zero measure sets when testing sharp hypotheses. We compare FBST performance to Chi-square, Likelihood-ratio and Markov chain tests, in three numerical experiments. The results suggest that FBST is a robust and high performance method for the HWE test, even in the presence of several alleles and small sample sizes

    Breastfeeding training for health professionals and resultant changes in breastfeeding duration

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    CONTEXT: Promotion of breastfeeding in Brazilian maternity hospitals. OBJECTIVE: To quantify changes in the breastfeeding duration among mothers served by hospitals exposed to the Wellstart-SLC course, comparing them with changes among mothers attended by institutions not exposed to this course. DESIGN: Randomized Institutional Trial. SETTING: The effects of training on breastfeeding duration was assessed in eight Brazilian hospitals assigned at random to either an exposed group (staff attending the Wellstart-SLC course) or a control group. SAMPLE: For each of the eight study hospitals, two cohorts of about 50 children were visited at home at one and six months after birth. The first cohort (n = 494) was composed of babies born in the month prior to exposure to the Wellstart-SLC course, and the second cohort (n = 476) was composed of babies born six months subsequent to this exposure. MAIN MEASUREMENTS: Kaplan-Meier curves were plotted to describe the weaning process and log-rank tests were used to assess statistical differences among survival curves. Hazard ratio (HR) estimates were calculated by fitting Cox proportional hazard regression models to the data. RESULTS: The increases in estimated, adjusted rates for children born in hospitals with trained personnel were 29% (HR = 0.71) and 20% (HR = 0.80) for exclusive and full breastfeeding, respectively. No changes were identified for total breastfeeding. CONCLUSION: This randomized trial supports a growing body of evidence that training hospital health professionals in breastfeeding promotion and protection results in an increase in breastfeeding duration.CONTEXTO: Promoção do aleitamento materno em maternidades brasileiras. OBJETIVO: Quantificar mudanças na duração do aleitamento materno de mães assistidas em maternidades expostas ao curso Wellstart-SLC, comparando-as com mudanças em mães assistidas por maternidades não expostas. TIPO DE ESTUDO: Ensaio institucional randomizado. LOCAL: Os efeitos do treinamento na duração do aleitamento materno foi avaliado em oito maternidades randomicamente alocadas ao grupo exposto (equipe freqüenta o curso Wellstart-SLC) ou controle. AMOSTRA: Em cada uma das oito maternidades, duas coortes de cerca de 50 crianças foram visitadas em suas casas ao completarem um e seis meses de vida. As primeiras coortes (n = 494) foram compostas de bebês nascidos no mês anterior ao treinamento, enquanto que as segundas coortes (n = 476) foram compostas por bebês nascidos seis meses após a exposição ao curso Weelstart-SLC. VARIÁVEIS ESTUDADAS: Para descrever o processo de desmame foram traçadas curvas de Kaplan-Meier. Para avaliar as diferenças estatísticas entre as curvas de sobrevivência foi utilizado o teste log-rank. Foram calculadas estimativas das razões de risco(HR) ajustando modelos de regressão de riscos proporcionais de Cox aos dados. RESULTADOS: O aumento estimado, a partir das razões ajustadas para crianças nascidas em hospitais com pessoal treinado, foi 29% (HR = 0,71) e 20% (HR = 0,80) para aleitamento exclusivo e pleno respectivamente. Não foram identificadas mudanças para o tempo de aleitamento total. CONCLUSÕES: Esse ensaio randomizado confirma evidências crescentes de que treinar profissionais de saúde em hospitais, na promoção e proteção do aleitamento materno, resulta em aumento do tempo de aleitamento materno.Universidade Federal de São Paulo (UNIFESP) Department of PediatricsUniversidade de Santo Amaro Maternal and Child Health Graduate ProgramUniversidade Federal de São Paulo (UNIFESP) School of Public HealthState of São Paulo State Health Secretariat Health InstituteUNIFESP, Department of PediatricsUNIFESP, School of Public HealthSciEL

    Safe Parallelism: Compiler Analysis Techniques for Ada and OpenMP

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    There is a growing need to support parallel computation in Ada to cope with the performance requirements of the most advanced functionalities of safety-critical systems. In that regard, the use of parallel programming models is paramount to exploit the benefits of parallelism. Recent works motivate the use of OpenMP for being a de facto standard in high-performance computing for programming shared memory architectures. These works address two important aspects towards the introduction of OpenMP in Ada: the compatibility of the OpenMP syntax with the Ada language, and the interoperability of the OpenMP and the Ada runtimes, demonstrating that OpenMP complements and supports the structured parallelism approach of the tasklet model. This paper addresses a third fundamental aspect: functional safety from a compiler perspective. Particularly, it focuses on race conditions and considers the fine-grain and unstructured capabilities of OpenMP. Hereof, this paper presents a new compiler analysis technique that: (1) identifies potential race conditions in parallel Ada programs based on OpenMP or Ada tasks or both, and (2) provides solutions for the detected races.This work was supported by the Spanish Ministry of Science and Innovation under contract TIN2015-65316-P, and by the FCT (Portuguese Foundation for Science and Technology) within the CISTER Research Unit (CEC/04234).Peer ReviewedPostprint (author's final draft

    Diverse tick-borne microorganisms identified in free-living ungulates in Slovakia

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    Background: Free-living ungulates are hosts of ixodid ticks and reservoirs of tick-borne microorganisms in central Europe and many regions around the world. Tissue samples and engorged ticks were obtained from roe deer, red deer, fallow deer, mouflon, and wild boar hunted in deciduous forests of south-western Slovakia. DNA isolated from these samples was screened for the presence of tick-borne microorganisms by PCR-based methods. Results: Ticks were found to infest all examined ungulate species. The principal infesting tick was Ixodes ricinus, identified on 90.4% of wildlife, and included all developmental stages. Larvae and nymphs of Haemaphysalis concinna were feeding on 9.6% of wildlife. Two specimens of Dermacentor reticulatus were also identified. Ungulates were positive for A. phagocytophilum and Theileria spp. Anaplasma phagocytophilum was found to infect 96.1% of cervids, 88.9% of mouflon, and 28.2% of wild boar, whereas Theileria spp. was detected only in cervids (94.6%). Importantly, a high rate of cervids (89%) showed mixed infections with both these microorganisms. In addition to A. phagocytophilum and Theileria spp., Rickettsia helvetica, R. monacensis, unidentified Rickettsia sp., Coxiella burnetii, "Candidatus Neoehrlichia mikurensis", Borrelia burgdorferi (s.l.) and Babesia venatorum were identified in engorged I. ricinus. Furthermore, A. phagocytophilum, Babesia spp. and Theileria spp. were detected in engorged H. concinna. Analysis of 16S rRNA and groEL gene sequences revealed the presence of five and two A. phagocytophilum variants, respectively, among which sequences identified in wild boar showed identity to the sequence of the causative agent of human granulocytic anaplasmosis (HGA). Phylogenetic analysis of Theileria 18S rRNA gene sequences amplified from cervids and engorged I. ricinus ticks segregated jointly with sequences of T. capreoli isolates into a moderately supported monophyletic clade. Conclusions: The findings indicate that free-living ungulates are reservoirs for A. phagocytophilum and Theileria spp. and engorged ixodid ticks attached to ungulates are good sentinels for the presence of agents of public and veterinary concern. Further analyses of the A. phagocytophilum genetic variants and Theileria species and their associations with vector ticks and free-living ungulates are required.Fil: Kazimírová, Mária. Slovak Academy of Sciences. Institute of Zoology; EslovaquiaFil: Hamšíková, Zuzana. Slovak Academy of Sciences. Institute of Zoology; EslovaquiaFil: Spitalská, Eva. Slovak Academy of Sciences. Institute of Virology. Biomedical Research Center,; EslovaquiaFil: Minichová, Lenka. Slovak Academy of Sciences. Institute of Virology. Biomedical Research Center,; EslovaquiaFil: Mahríková, Lenka. Slovak Academy of Sciences. Institute of Zoology; EslovaquiaFil: Caban, Radoslav. Široká ; EslovaquiaFil: Sprong, Hein. National Institute for Public Health and Environment.Laboratory for Zoonoses and Environmental Microbiology; Países BajosFil: Fonville, Manoj. National Institute for Public Health and Environment.Laboratory for Zoonoses and Environmental Microbiology; Países BajosFil: Schnittger, Leonhard. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Patobiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Kocianová, Elena. Slovak Academy of Sciences. Institute of Virology. Biomedical Research Center,; Eslovaqui

    Improving precision for detecting change in the shape of the cornea in patients with keratoconus

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    To investigate a method for precision analysis to discriminate true corneal change from measurement imprecision in keratoconus (KC). Thirty patients with KC and 30 healthy controls were included. Coefficients of repeatability and limits of agreement (LOA) were compared using multiple measurements for inter-observer and inter-device agreement with the Pentacam HR, Orbscan IIz, and Tomey Casia SS-1000. Correlation of repeated measurements was evaluated using a linear mixed effect model (also called random effect model). A formula was derived for the theoretical expected change in precision and compared with measured change. Correlation between measurements from the same eye was small (R = 0.13). The 99.73% LOA (3 SD) of the mean of three measurements, provided better precision than 95% LOA (2 SD) of single cut-off values as expected from statistical theory for uncorrelated measurements for evidence of a significant change in corneal shape in patients with keratoconus. This enabled the determination of cut-off values for the detection of true change in corneal shape. The mean of three repeated measurements will provide better precision when there is minimal correlation. Three (rather than two) standard deviations provides a precise estimate of the LOA within or between observers and can be used as a reliable measure for identifying stage-independent corneal shape changes (progression) in keratoconus

    Changes in grassland management and linear infrastructures associated to the decline of an endangered bird population

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    European grassland birds are experiencing major population declines, mainly due to changes in farmland management. We analyzed the role of habitat availability, grazing management and linear infrastructures (roads and power lines) in explaining spatial and temporal variation in the population density of little bustards (Tetrax tetrax) in Portugal, during a decade in which the species population size halved. We used data from 51 areas (totaling ca. 1,50,000 ha) that were sampled in two different periods (2003–2006 and 2016). In 2003–2006, when the species occurred at high densities, habitat availability was the only factor affecting spatial variation in bustard density. In the 2016 survey, variation in density was explained by habitat availability and livestock management, with reduced bird numbers in areas with higher proportions of cattle. Population declines across the study period were steeper in areas that initially held higher densities of bustards and in areas with a higher proportion of cattle in the total stocking rate. Areas with higher densities of power lines also registered greater density declines, probably due to avoidance behavior and to increased mortality. Overall, our results show little bustards are currently lacking high quality grassland habitat, whose persistence depends on extensive grazing regimes and low linear infrastructure densitiesinfo:eu-repo/semantics/publishedVersio
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