Precision of the optimized carbon monoxide rebreathing method to determine total haemoglobin mass and blood volume     

《European Journal of Sport Science》2013,13(1):68-77

Abstract

The aim of this study was to evaluate the influence of different apparatuses, procedures and calculations on the precision of the optimized carbon monoxide method. Total haemoglobin mass was determined twice on consecutive days in 11 subjects using both venous and capillary blood samples. To estimate loss of carbon monoxide due to exhalation, carbon monoxide concentration was measured by two portable carbon monoxide analysers (Fluke CO-220, Fluke, Norwich, UK and Pac 7000 Carbon Monoxide, Draeger Safety, Northumberland, UK) and alveolar ventilation was specified using an automated metabolic gas analysis system (Cosmed Quark b2, Cosmed, Rome, Italy). Blood volume was derived from total haemoglobin mass using haemoglobin concentration and haematocrit obtained in both the supine and the seated position. Two different formulae to calculate blood volume were also compared. Precision was good for both total haemoglobin mass and blood volume measurements performed on consecutive days (typical error < 2%). Using Fluke CO-220 analyser, an estimated alveolar ventilation and capillary blood, total haemoglobin mass (917±136 g) was similar when compared to the Pac 7000 Draeger CO-analyser (904±137 g; mean bias –13 g with 95% limits of agreement –26 to + 1 g, P=0.76), specified alveolar ventilation (911±132 g, mean bias –6 g with 95% limits of agreement –18 g to + 6 g, P =0.87) and venous blood (917±134 g, mean bias 0 g with 95% limits of agreement –38 to + 38 g, P=0.99), respectively. Blood volume determination was also not significantly affected by the supine vs. seated position (6.7±0.8 l vs. 6.6±0.8 l, P=0.56) but can deviate by ~0.6 l (P=0.01) depending on the formula applied. Thus, the good precision of the assessment of total haemoglobin mass and blood volume using the optimized carbon monoxide rebreathing method is not significantly influenced by the make of CO analyser, method of obtaining alveolar ventilation, blood sampling method and subject position, but should for longitudinal monitoring purposes use the same formula.  相似文献   

A theoretical framework and research agenda for studying team attributions in sport     

《International review of sport and exercise psychology》2013,6(2):121-144

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Effect of swimming velocity on arm coordination in the front crawl: a dynamic analysis     

L Seifert  D Chollet  BG Bardy 《Journal of sports sciences》2013,31(7):651-660

We examined the preferred mode of arm coordination in 14 elite male front-crawl swimmers. Each swimmer performed eight successive swim trials in which target velocity increased from the swimmer's usual 3000-m velocity to his maximal velocity. Actual swim velocity, stroke rate, stroke length and the different arm stroke phases were then calculated from video analysis. Arm coordination was quantified by an index of coordination based on the lag time between the propulsive phases of each arm. The index expressed the three coordination modes in the front crawl: opposition, catch-up and superposition. First, in line with the dynamic approach to movement coordination, the index of coordination could be considered as an order parameter that qualitatively captured arm coordination. Second, two coordination modes were observed: a catch-up pattern (index of coordination?=??8.43%) consisting of a lag time between the propulsive phases of each arm, and a relative opposition pattern (index of coordination?=?0.89%) in which the propulsive phase of one arm ended when the propulsive phase of the other arm began. An abrupt change in the coordination pattern occurred at the critical velocity of 1.8?m?·?s^?1, which corresponded to the 100-m pace: the swimmers switched from catch-up to relative opposition. This change in coordination resulted in a reorganization of the arm phases: the duration of the entry and catch phase decreased, while the duration of the pull and push phases increased in relation to the whole stroke. Third, these changes were coupled to increased stroke rate and decreased stroke length, indicating that stroke rate, stroke length, the stroke rate/stroke length ratio, as well as velocity, could be considered as control parameters. The control parameters can be manipulated to facilitate the emergence of specific coordination modes, which is highly relevant to training and learning. By adjusting the control and order parameters within the context of a specific race distance, both coach and swimmer will be able to detect the best adapted pattern for a given race pace and follow how arm coordination changes over the course of training.  相似文献   

Why do high jumpers use a curved approach?     

John CC Tan  MR Yeadon 《Journal of sports sciences》2013,31(8):775-780

Currently, all elite high jumpers use the Fosbury Flop technique with a curved approach. This suggests that the curved approach presents some clear advantage, although there is no general agreement upon the mechanism or the mechanics. This study aimed to determine the characteristics of the approach curve and to investigate how it contributes to the generation of somersault rotation. A simple theoretical model was used to demonstrate that a tightening approach curve would change the inward lean towards the centre of the curve into outwards lean. Three-dimensional video analysis was used to record the performances of two elite male high jumpers in competition. It was found that in each case the radius of the approach curve and the inward lean angle both decreased towards the end of the approach. The amount of outward lean angular velocity generated was shown to be a major proportion of the required somersault angular velocity for a jump. It was concluded that the main advantage of a curved approach was that it resulted in the generation of somersault velocity providing the curve tightened towards the end of the approach.  相似文献   

Confirmatory factor analysis of the Test of Performance Strategies (TOPS) among adolescent athletes     

Andrew M Lane  Chris Harwood  Peter C Terry  Costas I Karageorghis 《Journal of sports sciences》2013,31(9):803-812

The aim of the present study was to examine the factorial validity of the Test of Performance Strategies (TOPS; Thomas et al., ) among adolescent athletes using confirmatory factor analysis. The TOPS was designed to assess eight psychological strategies used in competition (i.e. activation, automaticity, emotional control, goal-setting, imagery, negative thinking, relaxation and self-talk,) and eight used in practice (the same strategies except negative thinking is replaced by attentional control). National-level athletes (n?=?584) completed the 64-item TOPS during training camps. Fit indices provided partial support for the overall measurement model for the competition items (robust comparative fit index?=?0.92, Tucker-Lewis index?=?0.88, root mean square error of approximation?=?0.05) but minimal support for the training items (robust comparative fit index?=?0.86, Tucker-Lewis index?=?0.81, root mean square error of approximation?=?0.06). For the competition items, the automaticity, goal-setting, relaxation and self-talk scales showed good fit, whereas the activation, emotional control, imagery and negative thinking scales did not. For the practice items, the attentional control, emotional control, goal-setting, imagery and self-talk scales showed good fit, whereas the activation, automaticity and relaxation scales did not. Overall, it appears that the factorial validity of the TOPS for use with adolescents is questionable at present and further development is required.  相似文献   

浅谈水利水电建设工程测量竣工资料的整编     

漆志强 《大众科技》2013,(6):75-76,106

测量竣工资料是工程竣工资料中的重要一环,能够真实、系统、直观的全面反映工程管理、施工依据和工程质量的资料,因为它对该项目的达标投产验收起着至关重要的决定作用。所以施工建设单位应必须转变观念、加强管理对测量内业资料的认识,测量竣工资料的整编过程要做到熟悉业主文件来文及国家档案规范的要求,同时不断的和设计、监理沟通对该资料的一致认同,从而编制出规范标准的工程测量竣工资料。  相似文献   

安徽省工业技术创新能力的测度与评价     

陶爱萍  宗查查 《科技管理研究》2013,(17)

从技术创新投入、技术创新产出、技术创新环境支撑三方面构建工业技术创新能力评价指标体系,利用主成分分析法对安徽省的工业技术创新能力进行测度与评价。结果显示,安徽省工业技术创新能力总体呈上升并加速提高的趋势,技术创新投入及专利制度对安徽省工业技术创新能力的影响较大。最后根据研究结果,提出提升安徽省工业技术创新能力的对策建议。  相似文献   

我国地区R&D效率及其影响因素探究——基于“科研产出—成果转化”视角   总被引：1，自引：1，他引：0  

蔡翔  崔晓兰  熊静  刘同存 《软科学》2013,27(3)

基于"科研产出—成果转化"视角,以2000～2008年的面板数据为基础,运用随机前沿分析方法研究了我国各地区R&D效率及其影响因素。研究结果表明:东部地区科研产出和成果转化效率皆高于中西部地区,中部地区科研产出效率高于西部地区,成果转化效率低于西部地区;科研产出的提高呈明显的资金推动型;政府支持力度和企业R&D投入力度对科研产出效率的提高有促进作用但不显著,外资吸纳能力能显著促进科研产出效率的提高,高新技术产业规模反而抑制科研产出效率的提高;政府支持力度、高新技术产业规模以及企业R&D投入力度对我国科研成果转化效率的提高有显著促进作用,外资吸纳能力抑制成果转化效率但不显著。  相似文献   

基于存续期的专利价值研究述评     

宋爽  陈向东 《科技管理研究》2013,33(12)

简要分析专利价值的本质,概述基于存续期的专利价值发展路径,介绍国内外价值评估的主要方法和典型实证结果,总结评价主要评估模型的优势和问题.认为国内应着重从三方面开展相关研究:分析专利价值形成因素,筛选专利价值的评估指标;结合我国专利活动和专利数据的特点,改进现有模型;开展基于国内专利数据的实证研究并进行国际比较.  相似文献   

激光脉冲测量技术解析     

尤建村  曹琛曼 《中国科技信息》2013,(22):36-38

介绍了超短激光脉冲技术的基本原理和产生过程,分析了超短脉冲的压缩技术以及近年来比较常用的几种测量技术直接测量法和间接测量法,重点研究了基于二次谐波的频率分辨光开关法（FROG）的脉冲测量法,以及这种测量方法的优缺点,并与自参考光谱相位相干电场重建法（缩写为SPIDER）进行了比较,分析了两种测量法各自的优缺点.  相似文献