289 research outputs found

    Qualitative perspectives on how Manchester United Football Club developed and sustained serial winning

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    Talent development in sport is well represented in scientific literature. Yet, the drive to protect ‘trade secrets’ often means that access to these high performing groups is rare, especially as these high level performances are being delivered. This leaves the details of high-end working practices absent from current academic commentary. As a result, clubs interested in developing excellent practice are left to build on personal initiative and insight and/or custom-and-practice, which is unlikely to yield successful outcomes. To address this shortfall the current study reports on prolonged engagement with a single high performing club, considering how their practice corresponds with existing sport talent development models. The paper ends by proposing an evidence-based, football-specific model for talent development, maintained high level performance and serial winning. This model emphasises four dominant features: culture, behavioral characteristics, practice engagement and the managing and guiding of performance ‘potential’. The study provides insights into the visceral reality of daily experiences across the life course of professional soccer, while advancing the evidence-base for understanding how Manchester United achieved their serial success

    Millennial scale persistence of organic carbon bound to iron in Arctic marine sediments

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    Burial of organic material in marine sediments represents a dominant natural mechanism of long-term carbon sequestration globally, but critical aspects of this carbon sink remain unresolved. Investigation of surface sediments led to the proposition that on average 10-20% of sedimentary organic carbon is stabilised and physically protected against microbial degradation through binding to reactive metal (e.g. iron and manganese) oxides. Here we examine the long-term efficiency of this rusty carbon sink by analysing the chemical composition of sediments and pore waters from four locations in the Barents Sea. Our findings show that the carbon-iron coupling persists below the uppermost, oxygenated sediment layer over thousands of years. We further propose that authigenic coprecipitation is not the dominant factor of the carbon-iron bounding in these Arctic shelf sediments and that a substantial fraction of the organic carbon is already bound to reactive iron prior deposition on the seafloor

    Is Mn-Bound Substrate Water Protonated in the S2 State of Photosystem II?

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    In spite of great progress in resolving the geometric structure of the water-splitting Mn4OxCa cluster in photosystem II, the binding sites and modes of the two substrate water molecules are still insufficiently characterized. While time-resolved membrane-inlet mass spectrometry measurements indicate that both substrate water molecules are bound to the oxygen-evolving complex (OEC) in the S2 and S3 states (Hendry and Wydrzynski in Biochemistry 41:13328–13334, 2002), it is not known (1) if they are both Mn-bound, (2) if they are terminal or bridging ligands, and (3) in what protonation state they are bound in the different oxidation states Si (i = 0, 1, 2, 3, 4) of the OEC. By employing 17O hyperfine sublevel correlation (HYSCORE) spectroscopy we recently demonstrated that in the S2 state there is only one (type of) Mn-bound oxygen that is water exchangeable. We therefore tentatively identified this oxygen as one substrate ‘water’ molecule, and on the basis of the finding that it has a hyperfine interaction of about 10 MHz with the electron spin of the Mn4OxCa cluster, we suggest that it is bound as a Mn–O–Mn bridge within a bis-μ2 oxo-bridged unit (Su et al. in J Am Chem Soc 130:786–787, 2008). Employing pulse electron paramagnetic resonance, 1H/2H Mims electron-nuclear double resonance and 2H-HYSCORE spectroscopies together with 1H/2H-exchange here, we test this hypothesis by probing the protonation state of this exchangeable oxygen. We conclude that this oxygen is fully deprotonated. This result is discussed in the light of earlier reports in the literature

    Sex-specific local life-history adaptation in surface- and cave-dwelling Atlantic mollies (Poecilia mexicana)

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    Cavefishes have long been used as model organisms showcasing adaptive diversification, but does adaptation to caves also facilitate the evolution of reproductive isolation from surface ancestors? We raised offspring of wild-caught surface- and cave-dwelling ecotypes of the neotropical fish Poecilia mexicana to sexual maturity in a 12-month common garden experiment. Fish were raised under one of two food regimes (high vs. low), and this was crossed with differences in lighting conditions (permanent darkness vs. 12:12 h light:dark cycle) in a 2 × 2 factorial design, allowing us to elucidate potential patterns of local adaptation in life histories. Our results reveal a pattern of sex-specific local life-history adaptation: Surface molly females had the highest fitness in the treatment best resembling their habitat of origin (high food and a light:dark cycle), and suffered from almost complete reproductive failure in darkness, while cave molly females were not similarly affected in any treatment. Males of both ecotypes, on the other hand, showed only weak evidence for local adaptation. Nonetheless, local life-history adaptation in females likely contributes to ecological diversification in this system and other cave animals, further supporting the role of local adaptation due to strong divergent selection as a major force in ecological speciation

    Co-resident Parents and Young People Aged 15–34: Who Does What Housework?

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    Young adults are now more likely to co-reside with their parents than previous generations, but domestic work patterns among this family type are largely unexplored. This study addresses this issue using Australian Bureau of Statistics Time Use Surveys (1992, 1997, 2006) and Poisson–Gamma regression analyses. It examines patterns in and correlates of domestic labor in two-generation households in which young people aged 15–34 co-reside with their parents (n = 1,946 households comprised of 2,806 young people and 5,129 parents). It differentiates between routine indoor tasks (cooking, cleaning, laundry), non-routine tasks (outdoor work, household management and maintenance, car care) and grocery shopping. Predictors of more time in some domestic activities by young people include being in neither employment nor education/training (NEET), being older, having a single parent and being in a non-English speaking household (young women). Young people being NEET, or female, are associated with less cooking time for mothers, but in the main when young people do perform domestic activities, they do not relieve their parents of those same activities, suggesting more time is spent by the household in total

    Reducing repeat pregnancies in adolescence: applying realist principles as part of a mixed-methods systematic review to explore what works, for whom, how and under what circumstances

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    BACKGROUND: Previous research has demonstrated emotional, psychological and educational harm to young mothers following unintended conceptions. The UK has one of the highest rates of pregnancies in adolescence in Western Europe with a high proportion of these being repeat pregnancies, making it a topic of interest for public health policy makers, and health and social care practitioners. As part of a wider mixed-methods systematic review, realist principles were applied to synthesise evidence about interventions aiming to reduce repeat pregnancies in adolescence.METHODS: A multi-streamed, mixed-methods systematic review was conducted searching 11 major electronic databases and 9 additional databases from 1995 onwards, using key terms such as pregnancy, teen or adolescent. The principles of realist synthesis were applied to all included literature to uncover theories about what works, for whom, how and in what context. Initial theory areas were developed through evidence scoping, group discussion by the authors and stakeholder engagement to uncover context + mechanism = outcome (CMO) configurations and related narratives.RESULTS: The searches identified 8,664 documents initially, and 403 in repeat searches, filtering to 81 included studies, including qualitative studies, randomised controlled trials, quantitative studies and grey literature. Three CMO configurations were developed. The individual experiences of young mothers' triggered self-efficacy, notions of perceived risks, susceptibility and benefits of pregnancy, resulting in the adolescent taking control of their fertility and sexual encounters. The choice between motherhood and other goals triggered notions of motivations, resulting in the adolescent managing their expectations of motherhood and controlling their fertility and sexual encounters. Barriers and facilitators to accessing services triggered notions of connectedness and self-determination; resulting in interventions that are tailored so they are relevant to young persons, and improve access to services and engagement with the issue of pregnancy in adolescence.CONCLUSIONS: Pregnancy in adolescence is a complex issue with many factors to consider. The conceptual platform described here could help guide policy makers and professionals towards a number of areas that need to be attended to in order to increase the likelihood of an intervention working to prevent rapid repeat pregnancy in adolescence.TRIAL REGISTRATION: PROSPERO CRD42012003168

    Molecular Epidemiology and Evolution of Human Respiratory Syncytial Virus and Human Metapneumovirus

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    Human respiratory syncytial virus (HRSV) and human metapneumovirus (HMPV) are ubiquitous respiratory pathogens of the Pneumovirinae subfamily of the Paramyxoviridae. Two major surface antigens are expressed by both viruses; the highly conserved fusion (F) protein, and the extremely diverse attachment (G) glycoprotein. Both viruses comprise two genetic groups, A and B. Circulation frequencies of the two genetic groups fluctuate for both viruses, giving rise to frequently observed switching of the predominantly circulating group. Nucleotide sequence data for the F and G gene regions of HRSV and HMPV variants from the UK, the Netherlands, Bangkok and data available from Genbank were used to identify clades of both viruses. Several contemporary circulating clades of HRSV and HMPV were identified by phylogenetic reconstructions. The molecular epidemiology and evolutionary dynamics of clades were modelled in parallel. Times of origin were determined and positively selected sites were identified. Sustained circulation of contemporary clades of both viruses for decades and their global dissemination demonstrated that switching of the predominant genetic group did not arise through the emergence of novel lineages each respiratory season, but through the fluctuating circulation frequencies of pre-existing lineages which undergo proliferative and eclipse phases. An abundance of sites were identified as positively selected within the G protein but not the F protein of both viruses. For HRSV, these were discordant with previously identified residues under selection, suggesting the virus can evade immune responses by generating diversity at multiple sites within linear epitopes. For both viruses, different sites were identified as positively selected between genetic groups

    Social Motility in African Trypanosomes

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    African trypanosomes are devastating human and animal pathogens that cause significant human mortality and limit economic development in sub-Saharan Africa. Studies of trypanosome biology generally consider these protozoan parasites as individual cells in suspension cultures or in animal models of infection. Here we report that the procyclic form of the African trypanosome Trypanosoma brucei engages in social behavior when cultivated on semisolid agarose surfaces. This behavior is characterized by trypanosomes assembling into multicellular communities that engage in polarized migrations across the agarose surface and cooperate to divert their movements in response to external signals. These cooperative movements are flagellum-mediated, since they do not occur in trypanin knockdown parasites that lack normal flagellum motility. We term this behavior social motility based on features shared with social motility and other types of surface-induced social behavior in bacteria. Social motility represents a novel and unexpected aspect of trypanosome biology and offers new paradigms for considering host-parasite interactions

    Phenotypic Plasticity in Response to the Social Environment: Effects of Density and Sex Ratio on Mating Behaviour Following Ecotype Divergence

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    The ability to express phenotypically plastic responses to environmental cues might be adaptive in changing environments. We studied phenotypic plasticity in mating behaviour as a response to population density and adult sex ratio in a freshwater isopod (Asellus aquaticus). A. aquaticus has recently diverged into two distinct ecotypes, inhabiting different lake habitats (reed Phragmites australis and stonewort Chara tomentosa, respectively). In field surveys, we found that these habitats differ markedly in isopod population densities and adult sex ratios. These spatially and temporally demographic differences are likely to affect mating behaviour. We performed behavioural experiments using animals from both the ancestral ecotype (“reed” isopods) and from the novel ecotype (“stonewort” isopods) population. We found that neither ecotype adjusted their behaviour in response to population density. However, the reed ecotype had a higher intrinsic mating propensity across densities. In contrast to the effects of density, we found ecotype differences in plasticity in response to sex ratio. The stonewort ecotype show pronounced phenotypic plasticity in mating propensity to adult sex ratio, whereas the reed ecotype showed a more canalised behaviour with respect to this demographic factor. We suggest that the lower overall mating propensity and the phenotypic plasticity in response to sex ratio have evolved in the novel stonewort ecotype following invasion of the novel habitat. Plasticity in mating behaviour may in turn have effects on the direction and intensity of sexual selection in the stonewort habitat, which may fuel further ecotype divergence
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