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G Stratton M Jones KR Fox K Tolfrey J Harris N Maffulli 《Journal of sports sciences》2013,31(4):383-390
AbstractDespite the performance concerns of dehydration in other sports, there are currently no data on the effects of rapid weight-loss on the physical and cognitive performance of jockeys in a sport-specific context. In a randomised crossover design, eight Great Britain (GB) male licensed jockeys were assessed for chest strength, leg strength, simulated riding performance (assessed by maximum pushing frequency on a mechanical riding simulator during the final two furlongs of a simulated 2 mile race) and simple reaction time after performing 45 min of exercise, during which euhydration was maintained (Control trial) or induced 2% dehydration (Rapid Weight-Loss trial). Reductions in both chest (–13.8 ± 3.03% vs. 0.62 ± 1.04%) and leg strength (–4.8 ± 4.8% vs. –0.56 ± 2.5%) were greater in Rapid Weight-Loss compared with Control (P < 0.01 and P = 0.04, respectively). Similarly, reductions in simulated riding performance were also greater (P = 0.05) in Rapid Weight-Loss (–2.8 ± 4.0%) compared with Control (–0.07 ± 1.5%), whereas there were no significant changes (P = 0.14) in simple reaction time. We conclude that a 2% reduction in body mass, as achieved by 45 min of moderate-intensity exercise undertaken in a sweatsuit (a common method of inducing acute dehydration by jockeys), significantly impairs maximum pushing frequency during a simulated race. In addition, the observed reductions in strength may also increase the occupational hazards associated with race riding. 相似文献
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Isaias Arriola‐Quiroz Walter H. Curioso MD MPH Maria Cruz‐Encarnacion Oscar Gayoso MD 《Health information and libraries journal》2010,27(2):148-154
Background: Many medical schools require a student thesis before graduation. Publishing results in a peer‐reviewed journal could be an indicator of scientific value and acceptability by the scientific community. The publication pattern of theses published by medical students in Peru is unknown. The aim of this study was to assess the characteristics and publication pattern of theses in biomedical‐indexed journals conducted by medical students in a university with the highest research output in Peru. Methods: Data from registered theses between 2000 and 2003 were obtained from the university library. Publication of theses in biomedical journals was assessed in 2008 by a search strategy using PubMed, Google Scholar, LILACS, LIPECS and SciELO. Results: Four hundred and eighty‐two medical theses were registered between 2000 and 2003; 85 (17.6%) were published in biomedical‐indexed journals. Of the published theses, 28 (5.8%) were published in MEDLINE‐indexed journals, 55 (11.4%) in SciELO‐indexed journals, 61 (12.6%) in LILACS‐indexed journals and 68 (14.1%) in LIPECS‐indexed journals. Most of the published theses (80%) were in Spanish and published in Peruvian journals; and 17 theses (20%) were published in foreign journals (all of them indexed in MEDLINE). In addition, 37 (43.5%) belong primarily to internal medicine, and 24 (28.2%) belong primarily to infectious diseases. Medical students were first authors in 71 (83.5%) of the articles. Conclusion: In this study, most of the published theses were in Spanish, published in local journals and indexed in LIPECS. The percentage of published theses in biomedical journals at this university is comparable with others coming from developed countries. 相似文献
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OBJECTIVE: This study is a meta-analysis of the literature exploring the relationship between child sexual abuse (CSA) and HIV risk behavior among women. Four outcome variables were tested: unprotected sex; sex with multiple partners; sex trading; and adult sexual revictimization. METHOD: Forty-six studies met the inclusion criteria and were included in the analysis, and separate meta-analyses were performed for each of the four dependent variables described above. RESULTS: Using the correlation coefficient r as an effect size estimate, results indicate an average effect size of .05 for the unprotected sex meta-analysis (N = 16 studies), .13 for the sex with multiple partners meta-analysis (N = 23 studies), .12 for the sex trading meta-analysis (N = 23 studies), and .17 for the adult sexual revictimization meta-analysis (N = 21 studies). We conducted a test of three potential moderator variables (source of sample, definition of CSA based on type of contact, and definition of CSA based on maximum age of victim). Results did not support the hypothesis that these three variables explain a significant amount of variability in effect sizes with one exception: Studies that define CSA more broadly to include adolescent victims (e.g., victims up to 17 years of age) had larger and more homogenous effect sizes for the sex trading meta-analysis than those that defined CSA as having occurred at younger ages. CONCLUSIONS: These findings suggest a small positive relationship between CSA and subsequent HIV risk behavior among women that varies as a function of how CSA and HIV risk behavior are operationalized. 相似文献
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＂爱＂类同素词是韩语背景学习者常混淆的一类词,主要混淆原因并非目的语词的意义相近、相通,而是母语和目的语知识的双重影响,其中以拆识复合词的影响最为严重。这启示词语偏误研究今后应多关注同类偏误现象背后的复杂原因,力求客观、准确地找到具体偏误原因,以便更有针对性地进行教学。 相似文献
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