899 resultados para Doping in sports


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An efficient market incorporates news into prices immediately and fully. Tests for efficiency in financial markets have been undermined by information leakage. We test for efficiency in sports betting markets – real-world markets where news breaks remarkably cleanly. Applying a novel identification to high-frequency data, we investigate the reaction of prices to goals scored on the ‘cusp’ of half-time. This strategy allows us to separate the market's response to major news (a goal), from its reaction to the continual flow of minor game-time news. On our evidence, prices update swiftly and fully.

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Introduction/Purpose: The effect of a triathlon competition on death of neutrophils from elite athletes was investigated. Methods: Blood was collected from 11 sedentary volunteers and 12 triathletes under rest and after a Half Ironman triathlon competition (2-km swimming, 80-km cycling, and 20-km running). Results: The triathlon competition increased DNA fragmentation, phosphatidylserine externalization, and reactive oxygen species production in neutrophils when compared to the results at rest. The proportion of neutrophils with mitochondrial transmembrane depolarization was increased in the triathletes at rest and after competition as compared with sedentary volunteers. Plasma levels of thiobarbituric acid reactive substances were increased in triathletes after competition. Expression of bcl-xL (antiapoptotic) was decreased and that of bax (proapoptotic) was increased, whereas intracellular neutral lipid content was lowered in neutrophils after the triathlon. A positive correlation was found between the proportion of neutrophils with DNA fragmentation and the plasma free fatty acid levels (r = 0.688, P < 0.05), which was elevated by threefold after competition. Plasma levels of oleic, linoleic, and stearic acids were increased in triathletes after the competition when compared with sedentary volunteers. The plasma concentration of these three fatty acids, measured after the triathlon competition, was toxic for 3-h cultured neutrophils obtained from sedentary volunteers. The maximal tolerable (nontoxic) concentration of the fatty acids by 3-h cultured neutrophils was 100 mu mol.L-1 for oleic and linoleic acids and 200 mu mol.L-1 for stearic acid. Conclusion: The triathlon competition induced neutrophil death possibly by apoptosis as indicated by DNA fragmentation and phosphatidylserine externalization. The increase in plasma levels of oleic, linoleic, and stearic acids induced by the competition may be involved in the neutrophil death observed possibly by increasing the production of reactive oxygen species and by decreasing the accumulation of intracellular neutral lipid.

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Purpose: Exercise training restores innate immune system cell function in post-myocardial infarction (post-MI) rats. However, studies of the involvement of lymphocyte (Ly) in the setting of the congestive heart failure (CHF) are few. To address this issue, we investigated the function of Ly obtained from cervical lymph nodes from post-MI CHF rats submitted to treadmill running training. Methods: Twenty-five male Wistar rats were randomly assigned to the following groups: rats submitted to ligation of the left coronary artery, which were sedentary (MI-S, N= 7, only limited activity) or trained (MI-T, N= 6, on a treadmill (0% grade at 13-20 m.m(-1)) for 60 min.d(-1), 5 d.wk(-1), for 8-10 wk); or sham-operated rats, which were sedentary (sham-S, N = 6) or trained (sham-T, N = 6). The incorporation of [2-C-14]-thymidine by Ly cultivated in the presence of concanavalin A (Con A) and lipopolysaccharide (LPS), cytokine production by Ly cultivated in the presence of phytohemagglutinin (PHA), and plasma concentration of glutamine were assessed in all groups, 48 h after the last exercise session. Results: Proliferative capacity was increased, following incubation with Con-A in the MI groups, when compared with the sham counterparts. When incubated in the presence of PHA, MI-S produced more IL-4 (96%) than sham-S (P < 0.001). The training protocol induced a 2.2-fold increase in the production of interleukin-2 (P < 0.001) of the cells obtained from the cervical lymph nodes of MI-T, compared with MI-S. Conclusion: The moderate endurance training protocol caused an increase in IL-2 production, and a trend toward the reversion of the Th-1/Th-2 imbalance associated with IL-4 production increased in the post-MI CHF animal model.

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A questão do Equilíbrio Competitivo é um tema importante da economia dos esportes profissionais nos Estados Unidos e na Europa. Muitas pesquisas foram feitas para estabelecer os critérios mais relevantes para avaliar a competitividade das ligas profissionais de futebol. Esta pesquisa analisou a relevância do Equilíbrio Competitivo como determinante da competitividade comparando o Brasileirão Série A com as nove principais ligas na Europa (Bélgica, Inglaterra, Alemanha, Holanda, França, Itália, Portugal, Escócia e Espanha). A competitividade é a capacidade de uma empresa (um clube) ou de uma indústria de enfrentar a concorrência efetiva ou potencial. A medida da competitividade deve levar em consideração uma série de fatores importantes como a qualidade e a relação qualidade/preço, a gestão de recursos humanos e a organização empresarial. Esse trabalho visa demonstrar que, apesar da incerteza do resultado ter sido considerado por muito tempo como um fator positivo de atratividade/interesse dos fãs nos esportes, um campeonato equilibrado poderia ter um efeito insignificante, para não dizer desprezível sobre a competitividade das ligas de futebol a longo prazo. Os resultados mostraram que o aumento do Equilíbrio Competitivo pode ser relevante para os campeonatos mais fracos (Bélgica, Holanda, Portugal, Escócia), mas nao dos cincos melhores (Alemanha, Espanha, França, Inglaterra, Itália). Consequentemente, o Equilíbrio Competitivo deve ser contemplado como uma variável desprezível quanto à competitividade das ligas de futebol, apesar do interesse crescente pelo conceito na literatura. Baseado principalmente em pesquisas de Dell'Osso e Symanski (1991) e de Oughton e Michie (2004), o índice HHI (Herfindahl-Hirschman) tem sido utilizado para determinar o nível de concentração de 11 ligas de futebol estudadas. Uma revisão da literatura sobre administração de futebol e esportes foi realizada.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Flexible and free-standing films from blends of polyurethane, based on castor oil, and polyaniline were obtained with various compositions by casting. Significant increase on conductivity followed by a considerable decrease on doping time was obtained by doping the films in N,N-dimethylformamide (DMF) solution with p-toluene sulphonic acid (TSA) or HCl instead of the conventional doping in aqueous solution. This doping efficiency is proposed to be due to an improved swelling of the blend structure caused by the solvent. The electrical conductivity increases significantly upon polyaniline content increase reaching 10(-2) S/cm for a polyaniline content of about 10% (w/w).

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)