608 research outputs found

    NIRS Measurements with Elite Speed Skaters: Comparison Between the Ice Rink and the Laboratory

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    Wearable, wireless near-infrared (NIR) spectrometers were used to compare changes in on-ice short-track skating race simulations over 1,500 m with a 3-min cycle ergometry test at constant power output (400 W). The subjects were six male elite short-track speed skaters. Both protocols elicited a rapid desaturation (∆TSI%) in the muscle during early stages (initial 20 s); however, asymmetry between right and left legs was seen in ΔTSI% for the skating protocol, but not for cycling. Individual differences between skaters were present in both protocols. Notably, one individual who showed a relatively small TSI% change (-10.7%, group mean = -26.1%) showed a similarly small change during the cycling protocol (-5.8%, group mean = -14.3%). We conclude that NIRS-detected leg asymmetry is due to the specific demands of short-track speed skating. However, heterogeneity between individuals is not specific to the mode of exercise. Whether this is a result of genuine differences in physiology or a reflection of differences in the optical properties of the leg remains to be determined

    GIFTS OF CHOSES IN ACTION

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    The Suspension of the Absolute Power of Alienation

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    In his Nature and Sources of Law, John Chipman Gray says, The Common Law has often been reproached with the lack of precision and certainty in its definitions, but, in truth, it is a great advantage of the Common Law, and of the mode of its development by judicial decision, that its definitions are never the matters resolved by the cases; they are never anything but dicta. If at the end of the sixteenth, or of the seventeenth, or even of the eighteenth century, there had been definitions binding by statute on the Courts; if the meaning of \u27contract\u27, and \u27malice\u27, and .\u27possession\u27, and \u27perpetuities\u27 had been fixed, what fetters would have been imposed on the natural development of the Law. And it is the great disadvantage of a code, that practising lawyers and jurists alike are hampered by the cast-iron classification and definitions of a former generation, which, in the advancement of legal thought and knowledge, are now felt to be imperfect and inadequate. \u27 Confining the illustration to the word \u27perpetuities\u27 the above quotation is so apt to the purpose of this article that it may well serve as a text for it

    Eucapnic Voluntary Hyperpnea: Gold Standard for Diagnosing Exercise-Induced Bronchoconstriction in Athletes?

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    In athletes, a secure diagnos is of exercise-induced bronchoconstriction (EIB) is dependent on objective testing. Evaluating spirometric indices of airflow before and following an exercise bout is intuitively the optimal means for the diagnosis; however, this approach is recognized as having several key limitations. Accordingly, alternative indirect bronchoprovocation tests have been recommended as surrogate means for obtaining a diagnosis of EIB. Of these tests, it is often argued that the eucapnic voluntary hyperpnea (EVH) challenge represents the ‘gold standard’. This article provides a state-of-the-art review of EVH, including an overview of the test methodology and its interpretation. We also address the performance of EVH against the other functional and clinical approaches commonly adopted for the diagnosis of EIB. The published evidence supports a key role for EVH in the diagnostic algorithm for EIB testing in athletes. However, its wide sensitivity and specificity and poor repeatability preclude EVH from being termed a ‘gold standard’ test for EIB

    Model-Based Analysis for Qualitative Data: An Application in Drosophila Germline Stem Cell Regulation.

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    Discovery in developmental biology is often driven by intuition that relies on the integration of multiple types of data such as fluorescent images, phenotypes, and the outcomes of biochemical assays. Mathematical modeling helps elucidate the biological mechanisms at play as the networks become increasingly large and complex. However, the available data is frequently under-utilized due to incompatibility with quantitative model tuning techniques. This is the case for stem cell regulation mechanisms explored in the Drosophila germarium through fluorescent immunohistochemistry. To enable better integration of biological data with modeling in this and similar situations, we have developed a general parameter estimation process to quantitatively optimize models with qualitative data. The process employs a modified version of the Optimal Scaling method from social and behavioral sciences, and multi-objective optimization to evaluate the trade-off between fitting different datasets (e.g. wild type vs. mutant). Using only published imaging data in the germarium, we first evaluated support for a published intracellular regulatory network by considering alternative connections of the same regulatory players. Simply screening networks against wild type data identified hundreds of feasible alternatives. Of these, five parsimonious variants were found and compared by multi-objective analysis including mutant data and dynamic constraints. With these data, the current model is supported over the alternatives, but support for a biochemically observed feedback element is weak (i.e. these data do not measure the feedback effect well). When also comparing new hypothetical models, the available data do not discriminate. To begin addressing the limitations in data, we performed a model-based experiment design and provide recommendations for experiments to refine model parameters and discriminate increasingly complex hypotheses

    Air quality and error quantity: pollution and performance in a high-skilled, quality-focused occupation

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    We provide the first evidence that short-term exposure to air pollution affects the work performance of a group of highly-skilled, quality-focused employees. We repeatedly observe the decision-making of individual professional baseball umpires, quasi-randomly assigned to varying air quality across time and space. Unique characteristics of this setting combined with high-frequency data disentangle effects of multiple pollutants and identify previously under-explored acute effects. We find a 1 ppm increase in 3-hour CO causes an 11.5% increase in the propensity of umpires to make incorrect calls and a 10 mg/m3 increase in 12-hour PM2.5 causes a 2.6% increase. We control carefully for a variety of potential confounders and results are supported by robustness and falsification checks

    Frequency-dependent selection predicts patterns of radiations and biodiversity

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    Most empirical studies support a decline in speciation rates through time, although evidence for constant speciation rates also exists. Declining rates have been explained by invoking niche-filling processes, whereas constant rates have been attributed to non-adaptive processes such as sexual selection, mutation, and dispersal. Trends in speciation rate and the processes underlying it remain unclear, representing a critical information gap in understanding patterns of global diversity. Here we show that the speciation rate is driven by frequency dependent selection. We used a frequency-dependent and DNA sequence-based model of populations and genetic-distance-based speciation, in the absence of adaptation to ecological niches. We tested the frequency-dependent selection mechanism using cichlid fish and Darwin's finches, two classic model systems for which speciation rates and richness data exist. Using negative frequency dependent selection, our model both predicts the declining speciation rate found in cichlid fish and explains their species richness. For groups like the Darwin's finches, in which speciation rates are constant and diversity is lower, the speciation rate is better explained by a model without frequency-dependent selection. Our analysis shows that differences in diversity are driven by larger incipient species abundance (and consequent lower extinction rates) with frequency-dependent selection. These results demonstrate that mutations, genetic-distance-based speciation, sexual and frequency-dependent selection are sufficient not only for promoting rapid proliferation of new species, but also for maintaining the high diversity observed in natural systems

    Predictor variables and screening protocol for depressive and anxiety disorders in cancer outpatients

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    Background Cancer patients are at increased risk of persistent depressive and anxiety symptoms and disorders compared to the general population. However, these issues are not always identified, which may worsen the prognosis and increase morbidity and mortality. Therefore, the objectives of this study are to identify predictor variables (demographic and clinical) for the development of mood and anxiety disorders in cancer outpatients and to propose a probabilistic screening protocol considering these variables and certain standardized screening instruments. Methods A total of 1,385 adults, of both genders, receiving outpatient cancer care were evaluated using a questionnaire and screening instruments. Thereafter, 400 of these subjects responded to the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (SCID-IV) by telephone to confirm or rule out the presence of a Current Major Depressive Episode (CMDE) or Anxiety Disorder (AD). Results Of the patients surveyed, 64% met the criteria for CMDE and 41% for AD. Female gender was found to be a risk factor for both disorders, and the presence of previous psychiatric history and marital status (divorced and widowed) were risk factors for anxiety disorders. When scoring above the recommended cutoff score, the screening instruments also indicated a risk of the studied disorders. Based on these findings, a screening protocol and nomograms were created for the quantification, combination and probabilistic estimate of risk, with accuracy indicators >0.68. Conclusion The prevalence rates for the disorders under study are extremely high in cancer patients. The use of the proposed protocol and nomogram can facilitate rapid and wide screening, thus refining triage and supporting the establishment of criteria for referral to mental health professionals, so that patients can be properly diagnosed and treated.info:eu-repo/semantics/publishedVersio
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