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991.
The aim of the study was to examine the relationships among body image, perception of physical abilities, and motor performance in boys involved in organized individual (i.e. tennis, fencing, judo) and team (i.e. soccer, handball, volleyball) sports. Altogether, 162 children (12.6 ± 1.0 years) were categorized as normal-weight (n = 85) or overweight (n = 77). Body image was measured using Collins' Child Figure Drawings, while individuals' perceptions of strength, speed, and agility were assessed using the Perceived Physical Ability Scale. Fitness tests of the standing long jump, 20 m sprint, and 10 × 5 m shuttle-run were also administered. Overweight boys showed greater body dissatisfaction and lower actual physical abilities than normal-weight peers. Participants involved in team sports reported lower body dissatisfaction and better performances in the shuttle-run compared with those involved in individual sports. For boys participating in team sports, body dissatisfaction was a significant mediator of the effect of body mass index on perceived physical ability. Results may influence intervention efforts, suggesting that targeting personal, psychological, and physical factors may prove efficient across physical activity locations and weight groups. 相似文献
992.
Dolan E O'Connor H McGoldrick A O'Loughlin G Lyons D Warrington G 《Journal of sports sciences》2011,29(8):791-799
In this study, we describe diet and lifestyle practices of professional jockeys. Participants completed a 59-item nutrition, lifestyle, and health questionnaire (n = 21) and a 7-day estimated food diary (n = 18). Acute weight loss strategies included the use of saunas (86%), exercising to induce sweating (81%), and restricted energy intake (71%). Of the smokers (38%), 56% used smoking to control weight. Most (86%) jockeys reported attaining a 2-kg weight loss for racing (if required) 24-48 h before or on the designated race-day. Mean daily energy intake (1803 ± 564 kcal) was low and appeared to provide an insufficient availability of energy for sustainment of usual daily and metabolic processes. Carbohydrate intake (3.7 ± 1.3 g · kg?1) was below recommendations for athletes. A substantial proportion of jockeys failed to meet the estimated average requirement and lower threshold intake for a number of micronutrients. Jockeys consumed well below (0-2) the recommended five daily servings of fruit and vegetables set by the World Health Organization. Pressures of the jockey lifestyle and rigid weight limits appear to encourage unhealthy weight management practices in this group and may risk long term-health. 相似文献
993.
This review presents an overview of literature that describes the applications of microfluidics to assay individual cells. We quantify the content of an individual mammalian cell, so that we can understand what criteria a single-cell assay must satisfy to be successful. We put in context the justification for single-cell assays and identify the characteristics that are relevant to single-cell assays. We review the literature from the past 24 months that describe the methods that use microfabrication-conventional or otherwise-and microfluidics in particular to study individual cells, and we present our views on how an increasing emphasis on three-dimensional cell culture and the demonstration of the first chemically defined cell might impact single-cell assays. 相似文献
994.
Xu G Lee DY Xie H Chiew D Hsieh TM Ali EM Lun Looi X Li MH Ying JY 《Biomicrofluidics》2011,5(3):34107-341079
Sample preparation is one of the most crucial processes for nucleic acids based disease diagnosis. Several steps are required for nucleic acids extraction, impurity washes, and DNA/RNA elution. Careful sample preparation is vital to the obtaining of reliable diagnosis, especially with low copies of pathogens and cells. This paper describes a low-cost, disposable lab cartridge for automatic sample preparation, which is capable of handling flexible sample volumes of 10 μl to 1 ml. This plastic cartridge contains all the necessary reagents for pathogen and cell lysis, DNA/RNA extraction, impurity washes, DNA/RNA elution and waste processing in a completely sealed cartridge. The entire sample preparation processes are automatically conducted within the cartridge on a desktop unit using a pneumatic fluid manipulation approach. Reagents transportation is achieved with a combination of push and pull forces (with compressed air and vacuum, respectively), which are connected to the pneumatic inlets at the bottom of the cartridge. These pneumatic forces are regulated by pinch valve manifold and two pneumatic syringe pumps within the desktop unit. The performance of this pneumatic reagent delivery method was examined. We have demonstrated the capability of the on-cartridge RNA extraction and cancer-specific gene amplification from 10 copies of MCF-7 breast cancer cells. The on-cartridge DNA recovery efficiency was 54-63%, which was comparable to or better than the conventional manual approach using silica spin column. The lab cartridge would be suitable for integration with lab-chip real-time polymerase chain reaction devices in providing a portable system for decentralized disease diagnosis. 相似文献
995.
We report a method for formulation of pectin microbeads using microfluidics. The technique uses biocompatible ingredients and allows for controlled external gelation with hydrogen and calcium ions delivered from an organic phase of rapeseed oil. This method allows for encapsulation of nanoparticles into the microparticles of gel and for control of the rate of their release. 相似文献
996.
Egon Brunswik proposed the concept of "representative design" for psychological experimentation, which has historically been overlooked or confused with another of Brunswik's terms, ecological validity. In this article, we reiterate the distinction between these two important concepts and highlight the relevance of the term representative design for sports psychology, practice, and experimental design. We draw links with ideas on learning design in the constraints-led approach to motor learning and nonlinear pedagogy. We propose the adoption of a new term, representative learning design, to help sport scientists, experimental psychologists, and pedagogues recognize the potential application of Brunswik's original concepts, and to ensure functionality and action fidelity in training and learning environments. 相似文献
997.
Hitting a cricket ball: what components of the interceptive action are most linked to expertise? 总被引:1,自引:0,他引:1
Weissensteiner JR Abernethy B Farrow D 《Sports biomechanics / International Society of Biomechanics in Sports》2011,10(4):324-338
Differences in interceptive skill between highly skilled and lesser skilled cricket batsmen were examined using a batting task that required participants to strike front-foot drive strokes from a machine-projected ball to a specified target. Task difficulty was manipulated by varying the width of the bat (normal, half, and third width) and target accuracy, and quality of bat-ball contact was monitored along with temporal and sequential elements of the hitting action. Analyses revealed that the highly skilled batsmen were distinguishable from less skilled counterparts by their higher accuracy under the normal and half-width bat conditions, significantly earlier initiation and completion of the front-foot stride, greater synchronization of the completion of the front-foot stride with the commencement of the downswing of the bat, and consistent timing of downswing relative to ball bounce and impact. In keeping with studies of other hitting sports, temporal and spatial coupling of the downswing to ball bounce to help minimize temporo-spatial error at the point of interception appeared critical to skilled performance. Implications for the understanding of interception and for coaching practice are briefly discussed. 相似文献
998.
8月23至26日,风城玫瑰以新科MVP的身份第二次来到中国。无论是在上海徐家汇篮球公园,广东体育馆还是北京朝阳体育馆内,罗斯都全倾全力地与中国的篮球兄弟进行了全轻全速地互动游戏——快速进攻、技巧挑战赛、MVP特训、1V1对抗赛。同时罗斯还担任U18夏季联赛的特别嘉宾为总冠军和MVP颁奖,见证并鼓励小球员全倾全力投入到篮球中。这也传递了阿迪达斯所倡导的allin精袖:如果你热爱你所从事的,就请全倾全力。 相似文献
999.
在高等教育领域,随着入学率的不断提高和教育成本的快速上涨,政府资金难以单独支撑高等教育的发展,所有国家都在寻求非政府资金来分担一部分教育成本,高等教育成本分担成为世界性的趋势.然而,高等教育财政是极其复杂的,与成本分担政策相关的一系列问题仍需厘清,包括学生与家庭分担的成本比例问题、学费问题、学生贷款问题等.本文分十个命题详细讨论了上述问题,试图以此指出并廓清高等教育财政政策中存在的普遍误解. 相似文献
1000.