Circadian rhythm effect on physical tennis performance in trained male players     

Álvaro López-Samanes  Diego Moreno-Pérez  José L. Maté-Muñoz  Raúl Domínguez  Jesús G. Pallarés  Ricardo Mora-Rodriguez 《Journal of sports sciences》2017,35(21):2121-2128

To determine the effect of circadian rhythm on neuromuscular responses and kinematics related to physical tennis performance, after a standardised warm-up, 13 highly competitive male tennis players were tested twice for serve velocity/accuracy (SVA), countermovement vertical jump (CMJ), isometric handgrip strength (IS), agility T-test (AGIL) and a 10-m sprint (10-m RUN). In a randomised, counter-balance order, tennis players underwent the test battery twice, either in the morning (i.e., AM; 9:00 h) and in the afternoon (i.e., PM; 16:30 h). Paired t-tests were used to analyse differences due to time-of-day in performance variables. Comparison of morning versus afternoon testing revealed that SVA (168.5 ± 6.5 vs. 175.2 ± 6.1 km · h^?1; P = 0.003; effect size [ES] = 1.07), CMJ (32.2 ± 0.9 vs. 33.7 ± 1.1 cm; P = 0.018; ES = 1.46), AGIL (10.14 ± 0.1 vs. 9.91 ± 0.2 s; P = 0.007; ES = 1.23) and 10-m RUN time (1.74 ± 0.1 vs. 1.69 ± 0.1 s; P = 0.021; ES = 0.67) were significantly blunted during the morning testing. However, IS was not affected by time-of-day (P = 0.891). Thus, tennis performance may be reduced when competing in the morning in comparison to early evening. Therefore, coaches and tennis players should focus on schedule the SVA, power, speed and agility training sessions in the afternoon.  相似文献   

Role of objectively measured sedentary behaviour in physical performance,frailty and mortality among older adults: A short systematic review     

Asier Mañas  Borja del Pozo-Cruz  Francisco José García-García  Amelia Guadalupe-Grau 《European Journal of Sport Science》2017,17(7):940-953

Sedentary behaviour (SB) has recently emerged as an independent risk factor for different health outcomes. Older adults accumulate long time in SB. Understanding the role that SB plays on health is crucial for a successful aging. This short systematic review summarizes the current evidence related to the effects of objectively measured SB on frailty, physical performance and mortality in adults ≥60?years old. The literature search produced 271 records for physical performance (n?=?119), frailty (n?=?31), and mortality (n?=?121). Finally, only 13 articles fulfilled the inclusion criteria and were included in this review. All articles but one included in the physical performance section (n?=?9) showed a negative association between longer time spent in SB and physical performance. A significant association of SB with higher odds of frailty was found, however this association disappeared after adjusting for cognitive status. Lastly, two of the three included studies showed positive associations between SB and mortality, but this effect decreased or even disappeared in the more adjusted models. In conclusion, there is consistency that SB is negatively associated with physical performance. However, the relationship between objectively measured SB and frailty incidence and mortality rates remains unclear and deserves further research. The use of homogenous criteria to assess SB and the inclusion of more robust research designs will help clarifying the independent effects that SB could have on physical performance, frailty, and mortality. This will ultimately help designing more efficient and comprehensive physical activity guidelines for older adults.  相似文献   

Guide to New Resources     

Ming Fang He  Maria José Botelho  Betty Christine Eng  William F. Dejean  Jill Aguilar  Isabel Nuñez 《Multicultural Perspectives》2013,15(2):114-125

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Guide to New Resources     

Ming Fang He  Maria José Botelho  Betty Christine Eng  William F. Dejean  Jill Aguilar  Isabel Nuñez 《Multicultural Perspectives》2013,15(3):175-186

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Guide to New Resources     

Ming Fang He  Jeff Sapp  Maria José Botelho  Isabel Nuñez  Wynnetta Scott-Simmons  Lincoln Johnson 《Multicultural Perspectives》2014,16(1):53-62

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Can we dispense with mimesis in representation?     

José A. Díez 《Metascience》2012,21(1):105-110

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La calidad en la educación abierta y a distancia en México     

Rodolfo herrero Ricaño  Héctor Barrón Soto 《The American journal of distance education》2013,27(1):68-71

Abstract

Since 1947, distance education in Mexico has had an important role for nonconventional populations. Considering that distance education is a heterogeneous and dynamic field, it is important to reflect on the need to improve quality as measured by our own standards. With that perspective in mind, a national meeting was organized to start a self‐diagnosis in which quality and access were the main concerns. Five hundred and twenty specialists from fifty‐one institutions participated in a national interactive synchronous meeting held in four regions. As a result of the meeting, thirty‐five criteria and 230 parameters of quality were established. The main conclusion of the meeting refers to the need for the elaboration of our own indicators for open and distance education.  相似文献   

从论文的引文分析探讨体育专业研究生的文献需求规律   总被引：5，自引：0，他引：5  

卢石  牛敬莹  刘文娟 《北京体育大学学报》1999,(2)

运用引文分析法对１９８１～１９９５年北京体育大学硕士和博士学位论文的１３１３８条引文数据进行了统计分析,得出如下结论：１）博士学位论文平均引文量与国外标准接近,而硕士平均引文量远远低于国外标准。２）引文来源以期刊为主,其次为图书和特种文献。３）体育学科与相关学科书刊引用量基本均衡。４）高频被引著者的论著引用学科广、时效性长。被引频次的大小与其专业性质有关。５）引文总量随年代的增长递增速度很快。  相似文献   

Spreading the digital word: ISI’s Electronic Library Project     

Isabel Czech 《Learned Publishing》1996,9(4):211-214

Describes the process behind – and the progress of – a unique project designed to explore many of the technical and economic issues pertaining to the implementation and use of an electronic library.  相似文献   

Concentration and Purification of Yacon?(Smallanthus sonchifolius) Root Fructooligosaccharides?Using Membrane Technology     

Maria Julia Ledur Alles  Isabel Cristina Tessaro  Caciano Pelayo Zapata Nore?a 《Food Technology and Biotechnology》2015,53(2):190-200

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