The effect of beetroot juice supplementation on repeat-sprint performance in hypoxia     

Georgina L. Kent  Brian Dawson  Lars R. McNaughton  Gregory R. Cox  Louise M. Burke  Peter Peeling 《Journal of sports sciences》2019,37(3):339-346

This investigation assessed the effect of dietary nitrate (NO₃^?) supplementation, in the form of beetroot juice (BR), on repeat-sprint performance in normoxia and normobaric hypoxia. 12 male team-sport athletes (age 22.3 ± 2.6 y, VO_2peak 53.1 ± 8.7 mL.kg^?1.min^?1) completed three exercise trials involving a 10 min submaximal warm-up and 4 sets of cycling repeat-sprint efforts (RSE; 9 × 4 s) at sea level (CON), or at 3000 m simulated altitude following acute supplementation (140 mL) with BR (HYP_BR; 13 mmol NO₃^?) or NO₃^–depleted BR placebo (HYP_PLA). Peak (PPO) and mean (MPO) power output, plus work decrement were recorded during the RSE task, while oxygen consumption (VO₂) was measured during the warm-up. There were no significant differences observed between HYP_BR and HYP_PLA for PPO or MPO; however, work decrement was reduced in the first RSE set in HYP_BR compared with HYP_PLA. There was a moderate effect for VO₂ to be lower following BR at the end of the 10 min warm-up (ES = 0.50 ± 0.51). Dietary NO₃^? may not improve repeat-sprint performance in hypoxia but may reduce VO₂ during submaximal exercise. Therefore, BR supplementation may be more effective for performance improvement during predominantly aerobic exercise.  相似文献   

Ali–Frazier 1: Black Gladiators,White Promoters,and the Economics of Big-Time Boxing     

Gregory Kaliss 《国际体育史杂志》2017,34(11):1003-1019

Abstract

The March 1971 heavyweight championship bout between undefeated black boxers Muhammad Ali and Joe Frazier elicited numerous responses. Ali, because of his brash persona, refusal to be drafted into the Vietnam War, and outspoken criticisms of white racism, had become a potent symbol of 1960s rebellion and Black Power. Frazier, by claiming the heavyweight championship while Ali was banished, cozying up to white politicians, and refusing to criticize the US government, made himself a worthy foil for Ali’s politics. But as the rhetoric surrounding the fight intensified, regarding black masculinity, patriotism, and community pride, one key aspect of the fight opened up debates in a surprising realm: the economics of black athletes and the possibilities and limitations of black capitalism. In an era when black capitalist programmes emerged nationwide, and when African-American athletes took on more vocal roles as community activists, the battles over the bout’s financial promotion became intense. While the boxers took home an unprecedented $2.5 million each for their participation, total revenues reached nearly $30 million. Discussions of the fight’s payout shed light on a wide range of economic issues facing the black community, and some of the unresolved issues in the quest for civil rights.  相似文献   

The Laurel Tree Cudgel: War and Walt Whitman in Allen Ginsberg's “America”     

Gregory M. Dandeles 《Journal of American culture (Malden, Mass. : 2003)》2013,36(3):221-229

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A problem in under-water acoustics     

Eve A.S. 《Journal of The Franklin Institute》1926,202(5):627-635

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Bookreviews     

R. P. Clark  Einar Lilja  Eve Malmqvist  Louis Arnaud Reid  Edmund King  John Downing  C. M. Fleming  Arnould Clausse  G. de Landsheere  Vernon Mallinson  Paul Nash  Tomio Goto  M. A. Brimer  Rudolf Cohen  Gerhard Pause  M. J. Langeveld  W. E. Vliegenthart  Emile Planchard 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1963,9(3):351-382

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A guide for the review of interactive videodisc instruction     

Robert B. Henderson  Gregory C. Sales 《Performance Improvement》1988,27(6):17-21

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Persistence to Graduation among At‐Risk Criminal Justice and Criminology Students: Experiences in Intervening with a Sophomore Cohort∗     

Gregory B. Morrison  Michael P. Brown 《Journal of Criminal Justice Education》2013,24(2):358-376

A Seminar targeting academically at‐risk sophomores was developed and introduced in 2002 to address weak connectedness to the university and poor academic abilities. We measured changes in approaches taken to college studies by those at‐risk sophomores who enrolled in the course, as well as employed a longitudinal, quasi‐experimental design to track this experimental group (n = 29) and the remainder of the at‐risk cohort as a comparison group (n = 36). Our preliminary findings suggest that the Seminar has had a variety of positive outcomes, the most impressive impact being that the experimental group had dramatically better retention and graduation rates than the comparison group.  相似文献   

The Art of the Impossible? A Case Study and Reflections on the Experience of Art in a Rural Kenyan Primary School     

Peter Gregory 《The International Journal of Art & Design Education》2012,31(3):265-275

The arguments for, and justification of, the value of teaching art in school have been made previously, but contextually these are often situated in Western affluence. This article explores the issues with a strikingly contrasted setting. The rural school in the study is approximately 30 minutes' drive from the nearest town, and the pupils are drawn from the surrounding rural bush area which is itself developmentally and materially poor in comparison to the UK. In school, the poverty seemed initially to relate to a lack of educational resources, but the reality experienced in the classroom may have also been linked to other issues. These included the desperate preoccupation with survival in difficult climatic conditions, a postcolonial legacy and the delicate balance of utilising resources without waste. What conclusions might then be drawn about the teaching of art? Utilising the work of others who have considered the issues in Kenya, this small‐scale ethnographic case study is presented with personal reflection and observations. The author would be pleased to hear from others with similar experiences or who have recognised additional issues in seemingly challenging circumstances.  相似文献   

Comparison of the computerized ACTIVITYGRAM instrument and the previous day physical activity recall for assessing physical activity in children     

Welk GJ  Dzewaltowski DA  Hill JL 《Research quarterly for exercise and sport》2004,75(4):370-380

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Physical activity,physiological, and psychomotor performance: a study of variously active older adult men     

Christensen CL  Payne VG  Wughalter EH  Yan JH  Henehan M  Jones R 《Research quarterly for exercise and sport》2003,74(2):136-142

This research examined varying levels of physical activity and psychomotor and physiological function in variously active older men. Very active moderately active, and low active participants were tested on simple (SRT) and choice reaction time (CRT), coincidence-anticipation timing (CAT), and VO2max. No significant differences for age or height were found, although percentage of fat, and weight were statistically different. Active groups were leaner and lighter. VO2max was significantly different between groups, as physically active groups yielded geater values. SRT and CAT also yielded significantly different results with more active participants showing better performance. No between-groups significant differences resulted for CRT. Generally, increased levels of physical activity were related to superior physiological outcomes and improved psychomotor peformance.  相似文献