Interpreting the Dispositional Flow Scale-2 scores: a pilot study of latent class factor analysis

The present study examined the extent to which scores on the Dispositional Flow Scale-2 (DFS-2) could differentiate individuals who frequently experience flow characteristics in physical activity from those who do not. A total of 993 participants completed the Japanese version of the DFS-2. Latent class factor analysis (LCFA), which combines the strengths of both latent class analysis and factor analysis, was conducted on the DFS-2 responses. Six classes were identified through a series of LCFAs and the patterns of the item-average scores for the nine flow attributes were found to be parallel among these classes. The top two and bottom two classes (19.3% and 13.4% of the whole sample) were considered the groups who experience flow characteristics frequently and seldom, respectively. These results indicated that individuals who often experience flow attributes in physical activity could be differentiated from those who do not based on their DFS-2 scores.     

Multi-Method Assessment of ADHD Characteristics in Preschool Children: Relations between Measures

Several forms of assessment tools, including behavioral rating scales and objective tests such as the Continuous Performance Test (CPT), can be used to measure inattentive and hyperactive/impulsive behaviors associated with Attention-Deficit/Hyperactivity Disorder (ADHD). However, research with school-age children has shown that the correlations between parent ratings, teacher ratings, and scores on objective measures of ADHD-characteristic behaviors are modest at best. In this study, we examined the relations between parent and teacher ratings of ADHD and CPT scores in a sample of 65 preschoolers ranging from 50 to 72 months of age. No significant associations between teacher and parent ratings of ADHD were found. Parent-ratings of both inattention and hyperactivity/impulsivity accounted for variance in CPT omission errors but not CPT commission errors. Teacher ratings showed evidence of convergent and discriminant validity when entered simultaneously in a hierarchical regression. These tools may be measuring different aspects of inattention and hyperactivity/impulsivity.     

Intensity and physiological strain of competitive ultra-endurance exercise in humans

The aim of this study was to determine the magnitude and pattern of intensity, and physiological strain, of competitive exercise performed across several days, as in adventure racing. Data were obtained from three teams of four athletes (7 males, 5 females; mean age 36 years, s = 11; cycling .VO(2 peak) 53.9 ml . kg(-1) . min(-1), s = 6.3) in an international race (2003 Southern Traverse; 96 - 116 h). Heart rates (HR) averaged 64% (95% confidence interval: +/- 4%) of heart rate range [%HRR = (HR - HR(min))/(HR(max) - HR(min)) x 100] during the first 12 h of racing, fell to 41% (+/-4%) by 24 h, and remained so thereafter. The level and pattern of heart rate were similar across teams, despite one leading and one trailing all other teams. Core temperature remained between 36.0 and 39.2 degrees C despite widely varying thermal stress. Venous samples, obtained before, during, and after the race, revealed increased neutrophil, monocyte and lymphocyte concentrations (P < 0.01), and increased plasma volume (25 +/- 10%; P < 0.01) with a stable sodium concentration. Standardized exercise tests, performed pre and post race, showed little change in the heart rate-work rate relationship (P = 0.53), but a higher perception of effort post race (P < 0.01). These results provide the first comprehensive report of physiological strain associated with adventure racing.     

Gross cycling efficiency is not altered with and without toe-clips

The aim of this study was to examine the claim that reductions of 8-18% in submaximal oxygen consumption (VO2) could be due to changing components on a Monark ergometer, from standard pedals without toe-clips or straps (flat pedals) to racing pedals of that era, which included toe-clips and straps (toe-clip pedals). This previously untested assertion was evaluated using 11 males (mean age 22.3 years, s= 1.2; height 1.82 m, s= 0.07; body mass 82.6 kg, s= 8.8) who completed four trials in a randomized, counterbalanced order at 60 rev min(-1) on a Monark cycle ergometer. Two trials were completed on flat pedals and two trials on toe-clip pedals. The Douglas bag method was used to assess VO2 and gross efficiency during successive 5-min workloads of 60, 120, 180, and 240 W. The mean VO2 was 2.1% higher for toe-clip pedals than flat pedals and there was a 99% probability that toe-clip pedals would not result in an 8% lower VO2. These results indicate that toe-clip pedals do not reduce VO2.     

Practical precooling: effect on cycling time trial performance in warm conditions

The purpose of this study was to compare the effects of two practical precooling techniques (skin cooling vs. skin + core cooling) on cycling time trial performance in warm conditions. Six trained cyclists completed one maximal graded exercise test (VO2(peak) 71.4 +/- 3.2 ml x kg(-1) x min(-1)) and four approximately 40 min laboratory cycling time trials in a heat chamber (34.3 degrees C +/- 1.1 degrees C; 41.2% +/- 3.0% rh) using a fixed-power/variable-power format. Cyclists prepared for the time trial using three techniques administered in a randomised order prior to the warm-up: (1) no cooling (control), (2) cooling jacket for 40 min (jacket) or (3) 30-min water immersion followed by a cooling jacket application for 40 min (combined). Rectal temperature prior to the time trial was 37.8 degrees C +/- 0.1 degrees C in control, similar in jacket (37.8 degrees C +/- 0.3 degrees C) and lower in combined (37.1 degrees C +/- 0.2 degrees C, P < 0.01). Compared with the control trial, time trial performance was not different for jacket precooling (-16 +/- 36 s, -0.7%; P = 0.35) but was faster for combined precooling (-42 +/- 25 s, - .8%; P = 0.009). In conclusion, a practical combined precooling strategy that involves immersion in cool water followed by the use of a cooling jacket can produce decrease in rectal temperature that persist throughout a warm-up and improve laboratory cycling time trial performance in warm conditions.     

An investigation of the in-game behaviours of professional, top-level youth soccer coaches

Although research into coaching has increased considerably during the last two decades, an area of neglect has been that of the professional youth coach. The aim of this study was to investigate the working behaviours of six top-level professional soccer coaches. Data were collected using a modified version of the Arizona State University Observation Instrument and semi-structured interviews. The triangulation of the data ensured that both the "what" and the "why" of the coaches' behaviour were considered. Results revealed a conscious and well thought out pattern of behaviour: silently monitoring, interspersed with clips of instruction coupled with praise and encouragement. The interviews revealed three themes underpinning this behaviour: developing game understanding, support and encouragement, and coaches' role and influences. The use of silence was the largest single behaviour, the efficacy of which was considered in light of theories of experiential and discovery learning.     

钢铁吸氧腐蚀实验的条件优化

在苏教版《实验化学》专题5中有关铁的吸氧腐蚀实验描述如下：取一片铁片,用砂纸擦去铁锈,在铁片上滴一滴含酚酞的食盐水（如图1）,静置1～2min,观察现象。     

国外图书馆视障服务及其对我国的启示

概述国外图书馆视障服务。以河南省为例,分析我国公共图书馆视障服务的现状与主要问题,指出我国应在政策和经济上支持公共图书馆开展视障服务,图书馆应加强盲人文献资源建设,重视视障服务宣传,多开展视障读者活动,以提高我国公共图书馆的整体视障服务水平。     

英语语法教学设计初探

《义务教育英语课程标准(2011年版)》强调要使学生尽可能多地从不同渠道,以不同方式接触和学习英语,亲身感受和直接体验语言、运用语言.英语语法教学常常让人觉得枯燥乏味,文章以人教社出版的高中英语新教材的语法项目——情态动词的教学实践为例,分析基于体验学习理念的英语语法教学设计.     

别因“怕脏”,剥夺孩子的触觉体验简

如今,“干不干净”成为很多家长养育孩子过程中最担心的问题。小区里,时常遇到这样的孩子与家长：孩子处在口欲期,什么东西都想放在嘴里感受一下,家长却百般阻挠;孩子想在地上爬爬、坐坐,家长却急着说“哎呀地上脏,不能坐,妈妈给你垫张纸再坐”;孩子想要捡起一片树叶,“脏!快放下!”;孩子一件事情还没做完,家长就在耳边“洗手、洗手”地重复催促。