Development and validation of Coaches’ Interpersonal Style Questionnaire

Purpose: The objectives were to develop and validate the Coaches’ Interpersonal Style Questionnaire. The Coaches’ Interpersonal Style Questionnaire analyzes the interpersonal style adopted by coaches when implementing their strategy of supporting or thwarting athletes’ basic psychological needs. Method: In Study 1, an exploratory factor analysis was performed with 265 Spanish male athletes, between 11- and 17-years-old, to confirm the internal structure of the questionnaire. Study 2 was conducted with 430 athletes, also between 11- and 17-years-old. Both confirmatory factor analysis and exploratory structural equation modeling were used to test a set of alternative models to find the best measurement model. Results: The hierarchical exploratory structural equation modeling model showed the best fit to the data and acceptable standardized factor loadings. Concurrent validity was revealed through correlational analysis of the basic psychological need satisfaction and frustration. Conclusion: This study provides a multi-dimensional questionnaire to assess coaches’ interpersonal style perceived by athletes.     

Novel mathematical model to estimate ball impact force in soccer

To assess ball impact force during soccer kicking is important to quantify from both performance and chronic injury prevention perspectives. We aimed to verify the appropriateness of previous models used to estimate ball impact force and to propose an improved model to better capture the time history of ball impact force. A soccer ball was fired directly onto a force platform (10 kHz) at five realistic kicking ball velocities and ball behaviour was captured by a high-speed camera (5,000 Hz). The time history of ball impact force was estimated using three existing models and two new models. A new mathematical model that took into account a rapid change in ball surface area and heterogeneous ball deformation showed a distinctive advantage to estimate the peak forces and its occurrence times and to reproduce time history of ball impact forces more precisely, thereby reinforcing the possible mechanics of ‘footballer’s ankle’. Ball impact time was also systematically shortened when ball velocity increases in contrast to practical understanding for producing faster ball velocity, however, the aspect of ball contact time must be considered carefully from practical point of view.     

Accuracy and precision of loadsol® insole force-sensors for the quantification of ground reaction force-based biomechanical running parameters

Force plates represent the “gold standard” in measuring running kinetics to predict performance or to identify the sources of running-related injuries. As these measurements are generally limited to laboratory analyses, wireless high-quality sensors for measuring in the field are needed. This work analysed the accuracy and precision of a new wireless insole forcesensor for quantifying running-related kinetic parameters. Vertical ground reaction force (GRF) was simultaneously measured with pit-mounted force plates (1?kHz) and loadsol^® sensors (100?Hz) under unshod forefoot and rearfoot running-step conditions. GRF data collections were repeated four times, each separated by 30 min treadmill running, to test influence of extended use. A repeated-measures ANOVA was used to identify differences between measurement devices. Additionally, mean bias and Bland–Altman limits of agreement (LoA) were calculated. We found a significant difference (p?® devices for these parameters. For these same parameters, the LoA analysis showed that 95% of all measurement differences between insole and force plate measurements were less than 12%, demonstrating high precision of the sensors. However, highly dynamic behaviour of GRF, such as force rate, is not yet sufficiently resolved by the insole devices, which is likely explained by the low sampling rate.     

An accurate estimation of the horizontal acceleration of a rower’s centre of mass using inertial sensors: a validation

For a valid determination of a rower’s mechanical power output, the anterior–posterior (AP) acceleration of a rower’s centre of mass (CoM) is required. The current study was designed to evaluate the accuracy of the determination of this acceleration using a full-body inertial measurement units (IMUs) suit in combination with a mass distribution model. Three methods were evaluated. In the first two methods, IMU data were combined with either a subject-specific mass distribution or a standard mass distribution model for athletes. In the third method, a rower’s AP CoM acceleration was estimated using a single IMU placed at the pelvis.

Experienced rowers rowed on an ergometer that was placed on two force plates, while wearing a full-body IMUs suit. Correspondence values between AP CoM acceleration based on IMU data (the three methods) and AP CoM acceleration obtained from force plate data (reference) were calculated. Good correspondence was found between the reference AP CoM acceleration and the AP CoM accelerations determined using IMU data in combination with the subject-specific mass model and the standard mass model (intraclass correlation coefficients [ICC] >?0.988 and normalized root mean square errors [nRMSE]?3.81%). Correspondence was lower for the AP CoM accelerations determined using a single pelvis IMU (0.877?Based on these results, we recommend determining a rower’s AP CoM acceleration using IMUs in combination with the standard mass model. Finally, we conclude that accurate determination of a rower’s AP CoM acceleration is not possible on the basis of the pelvis acceleration only.     

基于C／S和B／S混合架构的高校实验课选课管理系统设计与实现

随着本科教学质量改革的稳步推进,实验课程教学越来越引起高校的重视。如何提高实验课程的教学效果,如何方便学生选课,如何提高任课教师的管理效率,这些问题都亟待解决。针对实验选课的教学实际,设计并开发了一套基于C／S（客户机／服务器模式）和B／S（浏览器／服务器模式）两种架构混合的管理系统,C／S系统用于实现教师对课程的发布、学生对课程的选取、实验学时的管理及学生分组等日常管理,B／S系统用于实现学生网络选课、网上查询分组情况、网上查询实验课程内容、网上查询实验分数等功能。     

青光眼的针灸研究近况

综述介绍了2000年以来针灸治疗青光眼的临床和实验研究进展。内容涉及针刺取穴、各种针灸治疗方法,实验进展证实了针灸对青光眼的作用机制,为今后的临床和实验研究提供参考。     

Physical Performance Tests in Job Selection a Model for Empirical Validation

Abstract

The aim of this study was to establish the net energy cost of dribbling a soccer ball. Eight male footballers ran for 5 min on a treadmill at speeds of 9, 10.5, 12 and 13.5km ·h ^–1 while dribbling a football against a rebound box; running at each of these speeds without the ball constituted controls. Oxygen uptake ([Vdot]O ₂ ), perceived exertion (RPE) and blood lactate levels were measured and compared between the two conditions. The energy expended increased linearly with speed for both exercise modes, the mean increment of 1.24 kcal·min ^–1 caused by dribbling being independent of the speed of motion. Individual differences in efficiency of dribbling could not be explained by considering different patterns of stride characteristics. Similarly, RPE showed a constant elevation for dribbling over running at each speed, and a linear increase with speed of motion for both modes. Blood lactate increased disproportionately with speed for dribbling, onset of metabolic acidosis being attained at a lower speed for the experimental task. It was concluded that dribbling a ball does significantly increase the energy cost and perceived exertion of motion, as well as inducing disproportionate rises in blood lactate when performed at high speeds.     

Do instant messaging interruptions help or hinder knowledge workers’ task performance?

The modern workplace environment is filled with interruptions due to the necessity of coworkers to communicate with each other. Studies have revealed that interruptions can impact task performance (TP). Communication interruptions are due, in part, to the unavoidable side-effect of using technology to facilitate these interactions. This experimental case study reports about an investigation we conducted on the role of instant messaging interruptions (IMI) and its implications on knowledge workers’ TP in a workplace environment. We have gathered data from knowledge workers engaged in an e-learning activity. The case study included a total of 60 experimental observations and analysis of the 120 records revealed that the time to complete a task (TPtct) for certain types of tasks, was significantly affected by IMI. This case study addressed gaps in IM interruption research and practical knowledge about the role of instant messages in the organization. Previous research has been conducted in a laboratory environment with interruptions generated by means other than actual IM. This case study used IMI with participants working in their normal workplace. Findings were used to provide a set of lessons learned recommendations for managers when it comes to the use of IM in the workplace.     

初中学生冰上运动安全知识、技能实验干预研究

运用知识讲座、宣传手册、知识竞赛等方式对初一被试学生进行冰上运动安全实验干预,使用自编问卷评估实验前后被试学生冰上运动安全知识技能掌握情况,使用SPSS17．0对获得数据进行自身对照T检验。结果表明：学生通过知识讲座、技能培训、安全手册学习和知识竞赛等干预形式掌握了冰上运动安全知识、安全防护技能和运动损伤急救知识,说明实验干预内容、方法有效可行。     

走向生态文明新时代--兼论毕节试验区生态建设奖惩机制的构建

毕节试验区自1988年由时任贵州省委书记的胡锦涛同志倡导成立以来,始终坚持“先行先试”思想理念,努力践行“生态建设”主题,打造生态文明先行区。毕节试验区生态建设取得了较好的成绩,但生态脆弱、修复难度大仍然是当前的生态现实。要适应国家生态文明建设的新趋势、新常态,就必然要研究生态文明理论,探索生态文明建设机制战略决策和现实路径,推进毕节试验区生态文明建设的快速健康发展。探索有效的生态建设奖惩机制是当前的重大理论和现实课题。