1,876 research outputs found

    A Nevanlinna theorem for superharmonic functions on Dirichlet regular Greenian sets

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    summary:A generalization of Nevanlinna’s First Fundamental Theorem to superharmonic functions on Green balls is proved. This enables us to generalize many other theorems, on the behaviour of mean values of superharmonic functions over Green spheres, on the Hausdorff measures of certain sets, on the Riesz measures of superharmonic functions, and on differences of positive superharmonic functions

    Developing decision support for Foodbank South Africa's allocation system: an application of operational research techniques to aid decision-making at a not-for-profit organization

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    There is a dearth of research on the application of hard Operational Research (OR) techniques (simulation, linear programming, goal programming, etc.) in determining optimal ordering, inventory and allocation policies for goods within distribution systems in developing countries. This study aims to assist decision making at a not-for-profit organization (NPO), Foodbank South Africa (FBSA), within its allocation system through a combined ‘soft-hard’ OR approach. Two problem-structuring tools (soft OR), Causal Mapping (CM) and Soft System Methodology’s Root Definitions (RDs), are used to structure the organization's goals (in order to gain a comprehensive understanding of the decision-context) and gain a better understanding of the ‘decision-issues’ in the allocation system at its Cape Town warehouse

    Obituary: Alan Grahame Lloyd (1926-1999)

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    Teaching/Communication/Extension/Profession,

    Winning Isn\u27t Everything: Mood and Testosterone Regulate the Cortisol Response in Competition

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    Dominance contests are recurrent and widespread causes of stress among mammals. Studies of activation of the stress axis in social defeat – as reflected in levels of adrenal glucocorticoid, cortisol – have generated scattered and sometimes contradictory results, suggesting that biopsychological individual differences might play an important mediating role, at least in humans. In the context of a larger study of the regulation of endocrine responses to competition, we evaluated the notion that mood states, such as self-assurance and hostility, may influence cortisol reactivity to dominance cues via an interplay with baseline testosterone, considered as a potential marker of individual differences in dominance. Seventy healthy male university students (mean age 20.02, range 18–26) provided saliva samples before and after competing for fifteen minutes on a rigged computer task. After a winner was determined, all participants were assessed on their mood states through a standardized psychometric instrument (PANAS-X). Among winners of a rigged videogame competition, we found a significant interaction between testosterone and self-assurance in relation to post-competition cortisol. Specifically, self-assurance was associated with lower post-competition cortisol in subjects with high baseline testosterone levels, but no such relationship was observed in subjects with lower baseline testosterone levels. In losers of the competition no interaction effect between basal testosterone and hostility was observed. However, in this subgroup a significant negative relationship between basal testosterone and post-competition cortisol was evident. Overall, these findings provide initial support for the novel hypothesis that biological motivational predispositions (i.e. basal testosterone) and state (i.e. mood changes) may interact in regulating the hypothalamic-pituitary-adrenal axis activation after a social contest

    Masticatory biomechanics in the rabbit : a multi-body dynamics analysis

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    Acknowledgement We thank Sue Taft (University of Hull) for the µCT-scanning of the rabbit specimen used in this study. We also thank Raphaël Cornette, Jacques Bonnin, Laurent Dufresne, and l'Amicale des Chasseurs Trappistes (ACT) for providing permission and helping us capture the rabbits used for the in vivo bite force measurements at la Réserve Naturelle Nationale de St Quentin en Yvelines, France.Peer reviewedPublisher PD

    Integrating machine learning and decision support in tactical decision-making in rugby union

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    Funding: National Research Foundation of South Africa andthe Department of Higher Education and Training via the Teaching and Development Grant (IRMA:29113).Rugby union, like many sports, is based around sequences of play, yet this sequential nature is often overlooked, for example in analyses that aggregate performance measures over a fixed time interval. We use recent developments in convolutional and recurrent neural networks to predict the outcomes of sequences of play, based on the ordered sequence of actions they contain and where on the field these actions occur. The outcomes considered are gaining territory, retaining possession, scoring a try, and being awarded or conceding a penalty. We consider several artificial neural network architectures and compare their performance against baseline models. Accounting for sequential data and using field location improved classification accuracy over the baseline for some outcomes. We then investigate how these prediction models can provide tactical decision support to coaches. We demonstrate that tactical insight can be gained by conducting scenario analyses with data visualisations to investigate which strategies yield the highest probability of achieving the desired outcome.PostprintPeer reviewe

    A systematic review of interventions targeting physical activity and/or healthy eating behaviours in adolescents: practice and training

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    © 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/).Despite the many health benefits of physical activity (PA) and healthy eating (HE) most adolescents do not meet current guidelines which poses future health risks. This review aimed to (1) identify whether adolescent PA and HE interventions show promise at promoting behaviour change and maintenance, (2) identify which behaviour change techniques (BCTs) are associated with promising interventions, and (3) explore the optimal approaches to training deliverers of adolescent PA/HE interventions. Nine databases were searched for randomised controlled, or quasi-experimental, trials targeting 10–19 year olds, with a primary aim to increase PA/HE, measured at baseline and at least six months post-intervention, in addition to papers reporting training of deliverers of adolescent PA/HE interventions. Included were seven PA studies, three HE studies and four studies targeting both, with two training papers. For PA studies, two were promising post-intervention with two promising BCTs, and five were promising for maintenance with two promising BCTs. For HE studies, three were promising at post-intervention and four at maintenance, both with four promising BCTs. There is preliminary evidence that interventions support adolescents to improve their PA and HE behaviours over a period of at least six months.Peer reviewe
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