2,298 research outputs found

    The evolution, distribution and diversity of endogenous circoviral elements in vertebrate genomes

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    Circoviruses (family Circoviridae) are small, non-enveloped viruses that have short, single-stranded DNA genomes. Circovirus sequences are frequently recovered in metagenomic investigations, indicating that these viruses are widespread, yet they remain relatively poorly understood. Endogenous circoviral elements (CVe) are DNA sequences derived from circoviruses that occur in vertebrate genomes. CVe are a useful source of information about the biology and evolution of circoviruses. In this study, we screened 362 vertebrate genome assemblies in silico to generate a catalog of CVe loci. We identified a total of 179 CVe sequences, most of which have not been reported previously. We show that these CVe loci reflect at least 19 distinct germline integration events. We determine the structure of CVe loci, identifying some that show evidence of potential functionalization. We also identify orthologous copies of CVe in snakes, fish, birds, and mammals, allowing us to add new calibrations to the timeline of circovirus evolution. Finally, we observed that some ancient CVe group robustly with contemporary circoviruses in phylogenies, with all sequences within these groups being derived from the same host class or order, implying a hitherto underappreciated stability in circovirus-host relationships. The openly available dataset constructed in this investigation provides new insights into circovirus evolution, and can be used to facilitate further studies of circoviruses and CVe

    Rethinking clinical trials of transcranial direct current stimulation: Participant and assessor blinding is inadequate at intensities of 2mA

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    Copyright @ 2012 The Authors. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and 85 reproduction in any medium, provided the original author and source are credited. The article was made available through the Brunel University Open Access Publishing Fund.Background: Many double-blind clinical trials of transcranial direct current stimulation (tDCS) use stimulus intensities of 2 mA despite the fact that blinding has not been formally validated under these conditions. The aim of this study was to test the assumption that sham 2 mA tDCS achieves effective blinding. Methods: A randomised double blind crossover trial. 100 tDCS-naïve healthy volunteers were incorrectly advised that they there were taking part in a trial of tDCS on word memory. Participants attended for two separate sessions. In each session, they completed a word memory task, then received active or sham tDCS (order randomised) at 2 mA stimulation intensity for 20 minutes and then repeated the word memory task. They then judged whether they believed they had received active stimulation and rated their confidence in that judgement. The blinded assessor noted when red marks were observed at the electrode sites post-stimulation. Results: tDCS at 2 mA was not effectively blinded. That is, participants correctly judged the stimulation condition greater than would be expected to by chance at both the first session (kappa level of agreement (κ) 0.28, 95% confidence interval (CI) 0.09 to 0.47 p = 0.005) and the second session (κ = 0.77, 95%CI 0.64 to 0.90), p = <0.001) indicating inadequate participant blinding. Redness at the reference electrode site was noticeable following active stimulation more than sham stimulation (session one, κ = 0.512, 95%CI 0.363 to 0.66, p<0.001; session two, κ = 0.677, 95%CI 0.534 to 0.82) indicating inadequate assessor blinding. Conclusions: Our results suggest that blinding in studies using tDCS at intensities of 2 mA is inadequate. Positive results from such studies should be interpreted with caution.GLM is supported by the National Health & Medical Research Council of Australia ID 571090

    ANARQUISMO E VIOLÊNCIA: DEPURANDO A QUESTÃO

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    Este texto pretende investigar de maneira filosófica a questão da violência e seu lugar na luta entre os governantes – forças políticas e econômicas representadas pelo Estado e seu sistema Jurídico – e governados – mais especificamente as táticas de luta anarquista. Propõe-se apresentar as lógicas da violência e sua ótica nessas diferentes instâncias e seus diferentes pressupostos quando estão postas em conflito. Para isso, será realizado um diálogo entre expoentes do anarquismo clássico (Mikhail Bakunin e Piotr Kropotkin) e do contemporâneo Lorenzo Kom’boa Ervin com pensadores considerados marxistas heterodoxos que trataram deste tema (Georges Sorel e Walter Benjamin), a fim de tecer conexões insuspeitadas que auxiliem para o aprofundamento da questão

    SW-620 cells treated with topoisomerase I inhibitor SN-38: gene expression profiling

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    BACKGROUND: The goal of this study was to evaluate changes in gene expression in SW-620 cells in response to SN-38 in order to further elucidate the mechanisms by which SN-38 causes apoptosis and cell cycle arrest. METHODS: We used a quantitative gene expression microarray assay to identify the genes regulated by SN-38 treatment in colon cancer cells and confirmed our results with RT-PCR. By gene expression profiling, we first screened a proprietary list of about 22,000 genes. RESULTS: Treatment with SN-38 cells resulted in two-fold or greater alteration in the level of expression of 192 genes compared to control treatment. Most of the affected genes were not known to be responsive to SN-38 prior to this study. SN-38 treatment of these cells was found to affect the expression of various genes involved in DNA replication, transcription, signal transduction, growth factors, cell cycle regulation, and apoptosis, as well as other genes with unknown function. Changes in expression of 14 genes were confirmed by quantitative real-time polymerase chain reaction (RT-PCR). CONCLUSION: This study leads to an increased understanding of the biochemical pathways involved in SN-38-induced apoptosis and possibly to the identification of new therapeutic targets

    Insights into circovirus host range from the genomic fossil record

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    A diverse range of DNA sequences derived from circoviruses (family Circoviridae) have been identified in samples obtained from humans and domestic animals, often in association with pathological conditions. In the majority of cases, however, little is known about the natural biology of the viruses from which these sequences are derived. Endogenous circoviral elements (CVe) are DNA sequences derived from circoviruses that occur in animal genomes and provide a useful source of information about circovirus-host relationships. In this study we screened genome assemblies of 675 animal species and identified numerous circovirus-related sequences, including the first examples of CVe derived from cycloviruses. We confirmed the presence of these CVe in the germline of the elongate twig ant (Pseudomyrmex gracilis), thereby establishing that cycloviruses infect insects. We examined the evolutionary relationships between CVe and contemporary circoviruses, showing that CVe from ants and mites group relatively closely with cycloviruses in phylogenies. Furthermore, the relatively random interspersal of CVe from insect genomes with cyclovirus sequences recovered from vertebrate samples, suggested that contamination might be an important consideration in studies reporting these viruses. Our study demonstrates how endogenous viral sequences can inform metagenomics-based virus discovery. In addition, it raises doubts about the role of cycloviruses as pathogens of humans and other vertebrates

    Mental health, quality of life and self-management behaviours:online evaluation of inflammatory arthritis patients over 1 year of COVID-19 lockdowns

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    Objective: Patients with inflammatory arthritis were especially vulnerable to the psychosocial and health impacts of coronavirus disease 2019 (COVID-19) and the lockdowns. This study investigated the impact of these changes on mental health, physical health and quality of life for inflammatory arthritis patients over 1 year following the initial lockdown in the UK. Methods: Three hundred and thirty-eight participants with inflammatory arthritis completed an ambidirectional study consisting of online questionnaires at four time points for 1 year. The questionnaires assessed demographic information, inflammatory arthritis condition, mental health, physical symptoms, self-management behaviours, COVID-19 status and impacts. Means, linear regressions and structural equation modelling for mediations were conducted over 12 months. Results: Physical health concerns peaked during June 2020, then declined, but did not return to baseline. Depression was associated with worse quality of life at baseline, as shown by the beta coefficient, (β= 0.94, P &lt; 0.01), September (β = 0.92, P &lt; 0.01), November (β= 0.77, P &lt; 0.01) and 1 year (β = 0.77, P &lt; 0.01). Likewise, anxiety was associated with worse quality of life at baseline (β = 1.92, P &lt; 0.01), September (β = 2.06, P &lt; 0.01), November (β = 1.66, P = 0.03) and 1 year (β = 1.51, P = 0.02). The association between depression and quality of life was mediated by physical activity (β= 0.13, P &lt; 0.01) at baseline. The association between anxiety and quality of life was also mediated by physical activity (β = 0.25, P = 0.04) at baseline. Conclusion: Physical health continued to be worse 1 year later compared with before the COVID-19 lockdowns in patients with inflammatory arthritis. Mental health showed long-Term effects on quality of life, with an impact for ≥12 months. Lastly, physical activity mediated between mental health and quality of life in the short term.</p

    An in vitro stem cell model of human epiblast and yolk sac interaction.

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    Human embryogenesis entails complex signalling interactions between embryonic and extra-embryonic cells. However, how extra-embryonic cells direct morphogenesis within the human embryo remains largely unknown due to a lack of relevant stem cell models. Here, we have established conditions to differentiate human pluripotent stem cells (hPSCs) into yolk sac-like cells (YSLCs) that resemble the post-implantation human hypoblast molecularly and functionally. YSLCs induce the expression of pluripotency and anterior ectoderm markers in human embryonic stem cells (hESCs) at the expense of mesoderm and endoderm markers. This activity is mediated by the release of BMP and WNT signalling pathway inhibitors, and, therefore, resembles the functioning of the anterior visceral endoderm signalling centre of the mouse embryo, which establishes the anterior-posterior axis. Our results implicate the yolk sac in epiblast cell fate specification in the human embryo and propose YSLCs as a tool for studying post-implantation human embryo development in vitro.</i

    Developing a Data-Driven Safety Assessment Framework for RITI Communities in Washington State

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    The roadway safety of the Rural, Isolated, Tribal, or Indigenous (RITI) communities has become an important social issue in the United States. Official data from the Federal Highway Administration (FHWA) shows that, in 2012, 54 percent of all fatalities occurred on rural roads while only 19 percent of the US population lived in rural communities. Under the serious circumstances, this research aims to help the RITI communities to improve their roadway safety through the development of a roadway safety management system. Generally, a roadway safety management system includes two critical components, the baseline data platform and safety assessment framework. In our Year 1 and Year 2 CSET projects, a baseline data platform was developed by integrating the safety related data collected from the RITI communities in Washington State. This platform is capable of visualizing the accident records on the map. The Year 3 project further developed the safety data platform by developing crash data analysis and visualization functions. In addition, various roadway safety assessment methods had been developed to provide safety performance estimation, including historical accident data averages, predictions based on statistical and machine learning (ML) models, etc. Beside roadway safety assessment methods, this project investigated the safety countermeasures selection and recommendation methods for RITI communities. Specifically, the research team has reached out to RITI communities and established a formal research partnership with the Yakama Nation. The research team has conducted research on safety countermeasures analysis and recommendation for RITI communities

    Evidence for causal associations between prenatal and postnatal antibiotic exposure and asthma in children, England.

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    BACKGROUND: Higher risks of asthma have been observed in children with prenatal exposure to antibiotics and during early life compared with those who have not. However, the causality of such associations is unclear. OBJECTIVE: To assess whether exposure to antibiotics in early life had a causal effect in increasing the risk of asthma in children diagnosed at 5-8 years of life, and the impact in the target population. METHODS: Data were from electronic health records and questionnaires for children and their mothers in the Born in Bradford birth cohort. Exposure variables were prescriptions of systemic antibiotics to the mother during pregnancy (prenatal) and to the children at 0-24 months of life (postnatal). We assessed the association in 12,476 children with several approaches to deal with different sources of bias (triangulation): the interactions with mother's ethnicity, mode of delivery, and between prenatal and postnatal exposures; dose-response; and estimated the population attributable risk. RESULTS: There was an association between prenatal exposure at 7-27 days before the child's birth and asthma (adjusted OR = 1.40; 1.05, 1.87), but no association with the negative control exposure (before pregnancy) (adjusted OR = 0.99 (0.88, 1.12)). For postnatal exposure, the adjusted OR was 2.00 (1.71, 2.34), and for sibling analysis, it was 1.99 (1.00, 3.93). For postnatal exposure, the risk of asthma increased with the number of prescriptions. The observed effect of both exposures was lower among children with mothers of Pakistani ethnicity, but inconclusive (p > .25). The interaction between prenatal and postnatal exposures was also inconclusive (p = .287). The population attributable risk of postnatal exposure for asthma was 4.6% (0.1% for prenatal). CONCLUSIONS: We conclude that the associations between both late-pregnancy prenatal exposure to antibiotics and postnatal exposure to antibiotics and an increased risk of asthma are plausible and consistent with a causal effect
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