2,293 research outputs found

    Are youth sport talent identification and development systems necessary and healthy?

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    Talent identification and development systems (TIDS) are commonly used in professional sport to convert youth athletes into sporting stars of the future. Acknowledging that only a few athletes can "make it," the necessity and healthiness of TIDS have recently been questioned based on their increased professionalism, high training, and competition volumes, but limited effectiveness. In this short communication, we suggest that the key issues associated with TIDS are not due to their overall concept, but with how they are designed and implemented. It is recommended that researchers and practitioners determine the worth and value of TIDS by also evaluating the positive health of the athlete rather than solely focusing on performance outcomes. To achieve this, TIDS staff should shape and develop their values, expectations, and day-to-day routines to achieve positive health outcomes focusing on personal development and an athlete-centered culture. In business, this has been termed the concept of "Deliberately Developmental Organisation." TIDS can deploy the factors (e.g., high-quality staff, expert support services, quality facilities, and learning routines) characteristic of such organizations, to concurrently ensure positive impacts and minimize predictable negative outcomes without losing focus on a drive for sporting performance

    Understanding Silent Failures in Medical Image Classification

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    To ensure the reliable use of classification systems in medical applications, it is crucial to prevent silent failures. This can be achieved by either designing classifiers that are robust enough to avoid failures in the first place, or by detecting remaining failures using confidence scoring functions (CSFs). A predominant source of failures in image classification is distribution shifts between training data and deployment data. To understand the current state of silent failure prevention in medical imaging, we conduct the first comprehensive analysis comparing various CSFs in four biomedical tasks and a diverse range of distribution shifts. Based on the result that none of the benchmarked CSFs can reliably prevent silent failures, we conclude that a deeper understanding of the root causes of failures in the data is required. To facilitate this, we introduce SF-Visuals, an interactive analysis tool that uses latent space clustering to visualize shifts and failures. On the basis of various examples, we demonstrate how this tool can help researchers gain insight into the requirements for safe application of classification systems in the medical domain. The open-source benchmark and tool are at: https://github.com/IML-DKFZ/sf-visuals.Comment: Accepted at MICCAI 2

    A Call to Reflect on Evaluation Practices for Failure Detection in Image Classification

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    Reliable application of machine learning-based decision systems in the wild is one of the major challenges currently investigated by the field. A large portion of established approaches aims to detect erroneous predictions by means of assigning confidence scores. This confidence may be obtained by either quantifying the model's predictive uncertainty, learning explicit scoring functions, or assessing whether the input is in line with the training distribution. Curiously, while these approaches all state to address the same eventual goal of detecting failures of a classifier upon real-life application, they currently constitute largely separated research fields with individual evaluation protocols, which either exclude a substantial part of relevant methods or ignore large parts of relevant failure sources. In this work, we systematically reveal current pitfalls caused by these inconsistencies and derive requirements for a holistic and realistic evaluation of failure detection. To demonstrate the relevance of this unified perspective, we present a large-scale empirical study for the first time enabling benchmarking confidence scoring functions w.r.t all relevant methods and failure sources. The revelation of a simple softmax response baseline as the overall best performing method underlines the drastic shortcomings of current evaluation in the abundance of publicized research on confidence scoring. Code and trained models are at https://github.com/IML-DKFZ/fd-shifts

    MULTIPLICATION OF ANIMAL CELLS IN SUSPENSION MEASURED BY COLONY COUNTS

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    Archived with permission from the National Academy of Sciences USA. Originally published in Proceedings of the National Academy of Sciences USA volume 43 issue 6. Please refer to www.pnas.org for this series of publications. Author holds all copyright for this article.During the past few years the development of new techniques for the cultivation of animal cells in vitro has facilitated the quantitative study of many aspects of cell biology. At present the most commonly used method of propagating cell strains is based on the ability of cells to multiply while attached to a glass surface. The cells may be subcultured by removing them from the surface into suspension and then distributing them into other vessels, where they will again adhere to the glass and populate the surface. This procedure has been developed by Earle and his associates into the so-called quantitative replicate culture technique and applied to a variety of studies with animal cells. Despite the technical advance represented by this method, there are, nevertheless, serious experimental limitations inherent in the use of glass surfaces for cultivating large cell populations. Perhaps the most obvious of these is the problem of removing representative samples at will during the growth of a cell population. In addition, subculture requires the removal of cells from the surface, with consequent risk of cell injury.Aided in part by grants from the National Foundation for Infantile Paralysis, the Public Health Service of the National Institutes of Health of the United States, the National Cancer Institute of Canada, and the W. B. Boyd Memorial Fun

    Sound archaeology: terminology, Palaeolithic cave art and the soundscape

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    This article is focused on the ways that terminology describing the study of music and sound within archaeology has changed over time, and how this reflects developing methodologies, exploring the expectations and issues raised by the use of differing kinds of language to define and describe such work. It begins with a discussion of music archaeology, addressing the problems of using the term ‘music’ in an archaeological context. It continues with an examination of archaeoacoustics and acoustics, and an emphasis on sound rather than music. This leads on to a study of sound archaeology and soundscapes, pointing out that it is important to consider the complete acoustic ecology of an archaeological site, in order to identify its affordances, those possibilities offered by invariant acoustic properties. Using a case study from northern Spain, the paper suggests that all of these methodological approaches have merit, and that a project benefits from their integration

    Protein sequence analysis using the MPI Bioinformatics Toolkit

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    The MPI Bioinformatics Toolkit (https://toolkit.tuebingen.mpg.de) provides interactive access to a wide range of the best‐performing bioinformatics tools and databases, including the state‐of‐the‐art protein sequence comparison methods HHblits and HHpred. The Toolkit currently includes 35 external and in‐house tools, covering functionalities such as sequence similarity searching, prediction of sequence features, and sequence classification. Due to this breadth of functionality, the tight interconnection of its constituent tools, and its ease of use, the Toolkit has become an important resource for biomedical research and for teaching protein sequence analysis to students in the life sciences. In this article, we provide detailed information on utilizing the three most widely accessed tools within the Toolkit: HHpred for the detection of homologs, HHpred in conjunction with MODELLER for structure prediction and homology modeling, and CLANS for the visualization of relationships in large sequence datasets. Basic Protocol 1: Sequence similarity searching using HHpred Alternate Protocol: Pairwise sequence comparison using HHpred Support Protocol: Building a custom multiple sequence alignment using PSI‐BLAST and forwarding it as input to HHpred Basic Protocol 2: Calculation of homology models using HHpred and MODELLER Basic Protocol 3: Cluster analysis using CLAN

    Do youth soccer academies provide developmental experiences that prepare players for life beyond soccer? A retrospective account in the United Kingdom.

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    The professionalisation of soccer academies has intensified, with youth players exposed to demanding performance focused environments in pursuit of a career in the professional game. Yet, academies are also under increasing pressure to show that they develop players who can function in life beyond soccer. Therefore, this study explored the retrospective views of 13 ex-elite UK youth academy soccer players on whether their time within the academy provided developmental experiences that prepared them for life beyond soccer. We interviewed seven players who successfully progressed into professional contracts and six who did not. Players were recruited from two different academies to explore the developmental outcomes they associated with academy involvement and to unpick how those outcomes were achieved. Our findings showed that, promisingly, time in the academy provided both contracted and non-contracted players with transferable life skills as well as open educational and vocational doors – resulting in the majority of players leaving the environment being ‘(more) ready’ for life. However, these outcomes are not ‘automatic’ and were highly dependent on the interaction between three developmental contextual themes; i) what was demanded by the academy context, ii) what was encouraged within the academy context, and iii) the quality of interpersonal relationships. Beyond this, players’ attitudes, histories and wider socio-contextual influences were important in shaping (future) outcomes. With an eye on providing worthwhile experiences for all youth athletes involved, these findings provide insight into how academy contexts can simultaneously promote performance alongside positive developmental outcomes. Keywords: elite youth soccer, , Positive Youth Development, life skills, dual career, Talent identification and development system outcome

    The Streptococcus gordonii adhesin CshA protein binds host fibronectin via a catch-clamp mechanism

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    Adherence of bacteria to biotic or abiotic surfaces is a prerequisite for host colonization and represents an important step in microbial pathogenicity. This attachment is facilitated by bacterial adhesins at the cell surface. Because of their size and often elaborate multidomain architectures, these polypeptides represent challenging targets for detailed structural and functional characterization. The multifunctional fibrillar adhesin CshA, which mediates binding to both host molecules and other microorganisms, is an important determinant of colonization by Streptococcus gordonii, an oral commensal and opportunistic pathogen of animals and humans. CshA binds the high-molecular-weight glycoprotein fibronectin (Fn) via an N-terminal non-repetitive region, and this protein-protein interaction has been proposed to promote S. gordonii colonization at multiple sites within the host. However, the molecular details of how these two proteins interact have yet to be established. Here we present a structural description of the Fn binding N-terminal region of CshA, derived from a combination of X-ray crystallography, small angle X-ray scattering, and complementary biophysical methods. In vitro binding studies support a previously unreported two-state “catch-clamp” mechanism of Fn binding by CshA, in which the disordered N-terminal domain of CshA acts to “catch” Fn, via formation of a rapidly assembled but also readily dissociable pre-complex, enabling its neighboring ligand binding domain to tightly clamp the two polypeptides together. This study presents a new paradigm for target binding by a bacterial adhesin, the identification of which will inform future efforts toward the development of anti-adhesive agents that target S. gordonii and related streptococci

    Alterations in local chromatin environment are involved in silencing and activation of subtelomeric var genes in Plasmodium falciparum

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    Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1), encoded by the var gene family, undergoes antigenic variation and plays an important role in chronic infection and severe malaria. Only a single var gene is transcribed per parasite, and epigenetic control mechanisms are fundamental in this strategy of mutually exclusive transcription. We show that subtelomeric upsB var gene promoters carried on episomes are silenced by default, and that promoter activation is sufficient to silence all other family members. However, they are active by default when placed downstream of a second active var promoter, underscoring the significance of local chromatin environment and nuclear compartmentalization in var promoter regulation. Native chromatin covering the SPE2-repeat array in upsB promoters is resistant to nuclease digestion, and insertion of these regulatory elements into a heterologous promoter causes local alterations in nucleosomal organization and promoter repression. Our findings suggest a common logic underlying the transcriptional control of all var genes, and have important implications for our understanding of the epigenetic processes involved in the regulation of this major virulence gene family
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