530 research outputs found

    Causal effects of an absent crowd on performances and refereeing decisions during Covid-19

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    The Covid-19 pandemic has induced worldwide natural experiments on the effects of crowds. We exploit one of these experiments that took place over several countries in almost identical settings: professional football matches played behind closed doors within the 2019/20 league seasons. We find large and statistically significant effects on the number of yellow cards issued by referees. Without a crowd, fewer cards were awarded to the away teams, reducing home advantage. These results have implications for the influence of social pressure and crowds on the neutrality of decisions

    The impact of advance care planning on end of life care in elderly patients: randomised controlled trial

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    Objective To investigate the impact of advance care planning on end of life care in elderly patients

    Structure and decay of a proto-Y region in Tilapia, Oreochromis niloticus

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    Funding for Open Access provided by the UMD Libraries Open Access Publishing Fund.Sex-determination genes drive the evolution of adjacent chromosomal regions. Sexually antagonistic selection favors the accumulation of inversions that reduce recombination in regions adjacent to the sex-determination gene. Once established, the clonal inheritance of sex-linked inversions leads to the accumulation of deleterious alleles, repetitive elements and a gradual decay of sex-linked genes. This in turn creates selective pressures for the evolution of mechanisms that compensate for the unequal dosage of gene expression. Here we use whole genome sequencing to characterize the structure of a young sex chromosome and quantify sex-specific gene expression in the developing gonad. We found an 8.8 Mb block of strong differentiation between males and females that corresponds to the location of a previously mapped sex-determiner on linkage group 1 of Oreochromis niloticus. Putatively disruptive mutations are found in many of the genes within this region. We also found a significant female-bias in the expression of genes within the block of differentiation compared to those outside the block of differentiation. Eight candidate sex-determination genes were identified within this region. This study demonstrates a block of differentiation on linkage group 1, suggestive of an 8.8 Mb inversion encompassing the sex-determining locus. The enrichment of female-biased gene expression inside the proposed inversion suggests incomplete dosage compensation. This study helps establish a model for studying the early-to-intermediate stages of sex chromosome evolution.https://doi.org/10.1186/1471-2164-15-97

    Reversible Optogenetic Control of Subcellular Protein Localization in a Live Vertebrate Embryo.

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    We demonstrate the utility of the phytochrome system to rapidly and reversibly recruit proteins to specific subcellular regions within specific cells in a living vertebrate embryo. Light-induced heterodimerization using the phytochrome system has previously been used as a powerful tool to dissect signaling pathways for single cells in culture but has not previously been used to reversibly manipulate the precise subcellular location of proteins in multicellular organisms. Here we report the experimental conditions necessary to use this system to manipulate proteins in vivo. As proof of principle, we demonstrate that we can manipulate the localization of the apical polarity protein Pard3 with high temporal and spatial precision in both the neural tube and the embryo's enveloping layer epithelium. Our optimizations of optogenetic component expression and chromophore purification and delivery should significantly lower the barrier for establishing this powerful optogenetic system in other multicellular organisms

    Self-organized current transport through low angle grain boundaries in YBa2_2Cu3_3O7δ_{7-\delta} thin films, studied magnetometrically

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    The critical current density flowing across low angle grain boundaries in YBa2_2Cu3_3O7δ_{7-\delta} thin films has been studied magnetometrically. Films (200 nm thickness) were deposited on SrTiO3_3 bicrystal substrates containing a single [001] tilt boundary, with angles of 2, 3, 5, and 7 degrees, and the films were patterned into rings. Their magnetic moments were measured in applied magnetic fields up to 30 kOe at temperatures of 5 - 95 K; current densities of rings with or without grain boundaries were obtained from a modified critical state model. For rings containing 5 and 7 degree boundaries, the magnetic response depends strongly on the field history, which arises in large part from self-field effects acting on the grain boundary.Comment: 8 pages, including 7 figure

    Variation in pigmentation gene expression is associated with distinct aposematic color morphs in the poison frog Dendrobates auratus

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    Background: Color and pattern phenotypes have clear implications for survival and reproduction in many species. However, the mechanisms that produce this coloration are still poorly characterized, especially at the genomic level. Here we have taken a transcriptomics-based approach to elucidate the underlying genetic mechanisms affecting color and pattern in a highly polytypic poison frog. We sequenced RNA from the skin from four different color morphs during the final stage of metamorphosis and assembled a de novo transcriptome. We then investigated differential gene expression, with an emphasis on examining candidate color genes from other taxa. Results: Overall, we found differential expression of a suite of genes that control melanogenesis, melanocyte differentiation, and melanocyte proliferation (e.g., tyrp1, lef1, leo1, and mitf) as well as several differentially expressed genes involved in purine synthesis and iridophore development (e.g., arfgap1, arfgap2, airc, and gart). Conclusions: Our results provide evidence that several gene networks known to affect color and pattern in vertebrates play a role in color and pattern variation in this species of poison frog

    Arterial hyperoxia and in-hospital mortality after resuscitation from cardiac arrest

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    Introduction: Hyperoxia has recently been reported as an independent risk factor for mortality in patients resuscitated from cardiac arrest. We examined the independent relationship between hyperoxia and outcomes in such patients.Methods: We divided patients resuscitated from nontraumatic cardiac arrest from 125 intensive care units (ICUs) into three groups according to worst PaOlevel or alveolar-arterial Ogradient in the first 24 hours after admission. We defined 'hyperoxia' as PaOof 300 mmHg or greater, 'hypoxia/poor Otransfer' as either PaO 400 mmHg, hyperoxia had no independent association with mortality. Importantly, after adjustment for FiOand the relevant covariates, PaOwas no longer predictive of hospital mortality (P = 0.21).Conclusions: Among patients admitted to the ICU after cardiac arrest, hyperoxia did not have a robust or consistently reproducible association with mortality. We urge caution in implementing policies of deliberate decreases in FiOin these patients

    Relative hyperlactatemia and hospital mortality in critically ill patients: a retrospective multi-centre study

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    INTRODUCTION: Higher lactate concentrations within the normal reference range (relative hyperlactatemia) are not considered clinically significant. We tested the hypothesis that relative hyperlactatemia is independently associated with an increased risk of hospital death. METHODS: This observational study examined a prospectively obtained intensive care database of 7,155 consecutive critically ill patients admitted to the Intensive Care Units (ICUs) of four Australian university hospitals. We assessed the relationship between ICU admission lactate, maximal lactate and time-weighted lactate levels and hospital outcome in all patients and also in those patients whose lactate concentrations (admission n = 3,964, maximal n = 2,511, and time-weighted n = 4,584) were under 2 mmol.L-1 (i.e. relative hyperlactatemia). RESULTS: We obtained 172,723 lactate measurements. Higher admission and time-weightedlactate concentration within the reference range was independently associated with increased hospital mortality (admission odds ratio (OR) 2.1, 95% confidence interval (CI) 1.3 to 3.5, P = 0.01; time-weighted OR 3.7, 95% CI 1.9 to 7.00, P 0.75 mmol.L-1. Furthermore, in patients whose lactate ever exceeded 2 mmol.L-1, higher time-weighted lactate remained strongly associated with higher hospital mortality (OR 4.8, 95% CI 1.8 to 12.4, P 0.75 mmol.L-1 can be used by clinicians to identify patients at higher risk of death. The current reference range for lactate in the critically ill may need to be re-assessed
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