541 research outputs found

    The psychology of anterior cruciate ligament injury rehabilitation amongst professional rugby union players

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    [From the introduction:]Within professional contact sports, injury has been reported frequently by athletes as causing stress (Anshel, 2001; Noblet & Gifford, 2002). Particularly within rugby union where injury has been reported as one of the top four stressors experienced by elite adolescent players (Nicholls & Polman, 2007), and the most frequent stressor by adult professional players (Nicholls Holt, Polman, & Bloomfield, 2006). A variety of coping strategies are utilized to manage these stressors, with the effectiveness varying per player (Nicholls et al., 2006). Although to date no research has found a causal relationship between injury as a source of stress and the actual incidence of injury such research suggest that injury can significantly increase the stress experienced by athletes. This is supported by the findings that following serious sports injury, elite athletes have reported this to be a stressful experience (Gould, Udry, Bridges, & Beck, 1997a) which is manifested by concerns related to career, physical rehabilitation, social interactions, further injury, and return to prior performance levels (Gould et al., 1997; Tracey, 2003)

    The applicability of self-regulation theories in sport : goal adjustment capacities, stress appraisals, coping and well-being among athletes

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    Objectives: We examined a model, informed by self-regulation theories, which included goal adjustment capacities, appraisals of challenge and threat, coping, and well-being. Design: Prospective. Methods: Two hundred and twelve athletes from the United Kingdom (n = 147) or Australia (n = 65), who played team (n = 135) or individual sports (n = 77), and competed at international (n = 7), national (n = 11), county (n = 67), club (n = 84), or beginner (n = 43) levels participated in this study. Participants completed measures of goal adjustment capacities and stress appraisals two days before competing. Athletes also completed questions on coping and well-being within three hours of their competition ending. Results: The way an athlete responds to an unattainable goal is associated with his or her well-being in the period leading up to and including the competition. Goal reengagement positively predicted well-being, whereas goal disengagement negatively predicted well-being. Further, goal reengagement was positively associated with challenge appraisals, which in turn was linked to task-oriented coping, and task-oriented coping positively associated with well-being. Conclusion: When highly-valued goals become unattainable, consultants could encourage athletes to seek out alternative approaches to achieve the same goal or help them develop a completely new goal

    Motivation and Behaviour Change in Parkrun Participants in the Western Cape Province, South Africa

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    Mass participation events are promoted in South Africa as a positive public health initiative. Parkrun has grown to be one of the most popular. The present study identifies the motives of residents in the Western Cape Province to join parkrun and how their involvement influences future physical activity levels. Participants (N = 1787) completed a survey consisting of demographic history, parkrun participation history, motivations for participation, and physical activity-related behaviour changes associated with parkrun participation. The majority of participants were female (n = 952) and over 50 years of age (median = 50; IQR = 38–59). Along with health-related benefits, the provision of a safe and organised event was reported as a key motive to participate. The social connectedness developed by parkrun encouraged continued participation and promoted uptake of more physical activity. Close to half the participants reported increases in physical activity levels after joining parkrun, which demonstrates the benefit obtained from participation in structured mass participation events. With the large diversity in socioeconomic status in South Africa related to physical activity levels, parkrun provides a protected and engaging environment that provides opportunity for increased physical activity and potentially reducing the burden on the healthcare system

    Tunable solid-state fluorescent materials for supramolecular encryption

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    Tunable solid-state fluorescent materials are ideal for applications in security printing technologies. A document possesses a high level of security if its encrypted information can be authenticated without being decoded, while also being resistant to counterfeiting. Herein, we describe a heterorotaxane with tunable solid-state fluorescent emissions enabled through reversible manipulation of its aggregation by supramolecular encapsulation. The dynamic nature of this fluorescent material is based on a complex set of equilibria, whose fluorescence output depends non-linearly on the chemical inputs and the composition of the paper. By applying this system in fluorescent security inks, the information encoded in polychromic images can be protected in such a way that it is close to impossible to reverse engineer, as well as being easy to verify. This system constitutes a unique application of responsive complex equilibria in the form of a cryptographic algorithm that protects valuable information printed using tunable solid-state fluorescent materials

    The Boolean Algebra of Cubical Areas as a Tensor Product in the Category of Semilattices with Zero

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    In this paper we describe a model of concurrency together with an algebraic structure reflecting the parallel composition. For the sake of simplicity we restrict to linear concurrent programs i.e. the ones with no loops nor branching. Such programs are given a semantics using cubical areas. Such a semantics is said to be geometric. The collection of all these cubical areas enjoys a structure of tensor product in the category of semi-lattice with zero. These results naturally extend to fully fledged concurrent programs up to some technical tricks.Comment: In Proceedings ICE 2014, arXiv:1410.701

    Atomic and Molecular Opacities for Brown Dwarf and Giant Planet Atmospheres

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    We present a comprehensive description of the theory and practice of opacity calculations from the infrared to the ultraviolet needed to generate models of the atmospheres of brown dwarfs and extrasolar giant planets. Methods for using existing line lists and spectroscopic databases in disparate formats are presented and plots of the resulting absorptive opacities versus wavelength for the most important molecules and atoms at representative temperature/pressure points are provided. Electronic, ro-vibrational, bound-free, bound-bound, free-free, and collision-induced transitions and monochromatic opacities are derived, discussed, and analyzed. The species addressed include the alkali metals, iron, heavy metal oxides, metal hydrides, H2H_2, H2OH_2O, CH4CH_4, COCO, NH3NH_3, H2SH_2S, PH3PH_3, and representative grains. [Abridged]Comment: 28 pages of text, plus 22 figures, accepted to the Astrophysical Journal Supplement Series, replaced with more compact emulateapj versio

    The Higher Derivative Expansion of the Effective Action by the String Inspired Method. Part II

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    We apply the string inspired worldline formalism to the calculation of the higher derivative expansion of one-loop effective actions in non-Abelian gauge theory. For this purpose, we have completely computerized the method, using the symbolic manipulation programs FORM, PERL and M. Explicit results are given to sixth order in the inverse mass expansion, reduced to a minimal basis of invariants specifically adapted to the method. Detailed comparisons are made with other gauge-invariant algorithms for calculating the same expansion. This includes an explicit check of all coefficients up to fifth order.Comment: 37 pages, LaTeX, 3 figures, typos corrected, to appear in Ann. Phys. (N.Y.

    Striking Phenotypic Variation yet Low Genetic Differentiation in Sympatric Lake Trout (Salvelinus namaycush)

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    The study of population differentiation in the context of ecological speciation is commonly assessed using populations with obvious discreteness. Fewer studies have examined diversifying populations with occasional adaptive variation and minor reproductive isolation, so factors impeding or facilitating the progress of early stage differentiation are less understood. We detected non-random genetic structuring in lake trout (Salvelinus namaycush) inhabiting a large, pristine, postglacial lake (Mistassini Lake, Canada), with up to five discernible genetic clusters having distinctions in body shape, size, colouration and head shape. However, genetic differentiation was low (FST = 0.017) and genetic clustering was largely incongruent between several population- and individual-based clustering approaches. Genotype- and phenotype-environment associations with spatial habitat, depth and fish community structure (competitors and prey) were either inconsistent or weak. Striking morphological variation was often more continuous within than among defined genetic clusters. Low genetic differentiation was a consequence of relatively high contemporary gene flow despite large effective population sizes, not migration-drift disequilibrium. Our results suggest a highly plastic propensity for occupying multiple habitat niches in lake trout and a low cost of morphological plasticity, which may constrain the speed and extent of adaptive divergence. We discuss how factors relating to niche conservatism in this species may also influence how plasticity affects adaptive divergence, even where ample ecological opportunity apparently exists

    Striking Phenotypic Variation yet Low Genetic Differentiation in Sympatric Lake Trout (Salvelinus namaycush)

    Get PDF
    The study of population differentiation in the context of ecological speciation is commonly assessed using populations with obvious discreteness. Fewer studies have examined diversifying populations with occasional adaptive variation and minor reproductive isolation, so factors impeding or facilitating the progress of early stage differentiation are less understood. We detected non-random genetic structuring in lake trout (Salvelinus namaycush) inhabiting a large, pristine, postglacial lake (Mistassini Lake, Canada), with up to five discernible genetic clusters having distinctions in body shape, size, colouration and head shape. However, genetic differentiation was low (FST = 0.017) and genetic clustering was largely incongruent between several population- and individual-based clustering approaches. Genotype- and phenotype-environment associations with spatial habitat, depth and fish community structure (competitors and prey) were either inconsistent or weak. Striking morphological variation was often more continuous within than among defined genetic clusters. Low genetic differentiation was a consequence of relatively high contemporary gene flow despite large effective population sizes, not migration-drift disequilibrium. Our results suggest a highly plastic propensity for occupying multiple habitat niches in lake trout and a low cost of morphological plasticity, which may constrain the speed and extent of adaptive divergence. We discuss how factors relating to niche conservatism in this species may also influence how plasticity affects adaptive divergence, even where ample ecological opportunity apparently exists
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