A comparison of methods to determine bilateral asymmetries in vertical leg stiffness

Whilst the measurement and quantification of vertical leg stiffness (K_vert) asymmetry is of important practical relevance to athletic performance, literature investigating bilateral asymmetry in K_vert is limited. Moreover, how the type of task used to assess K_vert may affect the expression of asymmetry has not been properly determined. Twelve healthy males performed three types of performance tasks on a dual force plate system to determine K_vert asymmetries; the tasks were (a) bilateral hopping, (b) bilateral drop jumping and (c) unilateral drop jumping. Across all the three methods, K_vert was significantly different between compliant and stiff limbs (P < 0.001) with a significant interaction effect between limb and method (P = 0.005). Differences in K_vert between compliant and stiff limbs were ?5.3% (P < 0.001), ?21.8% (P = 0.007) and ?15.1% (P < 0.001) for the bilateral hopping, bilateral drop jumping and unilateral drop jumping methods, respectively. All the three methods were able to detect significant differences between compliant and stiff limbs, and could be used as a diagnostic tool to assess K_vert asymmetry. Drop jumping tasks detected larger K_vert asymmetries than hopping, suggesting that asymmetries may be expressed to a greater extent in acyclic, maximal performance tasks.     

Dribbling determinants in sub-elite youth soccer players

Dribbling speed in soccer is considered critical to the outcome of the game and can assist in the talent identification process. However, little is known about the biomechanics of this skill. By means of a motion capture system, we aimed to quantitatively investigate the determinants of effective dribbling skill in a group of 10 Under-13 sub-elite players, divided by the median-split technique according to their dribbling test time (faster and slower groups). Foot-ball contacts cadence, centre of mass (CoM), ranges of motion (RoM), velocity and acceleration, as well as stride length, cadence and variability were computed. Hip and knee joint RoMs were also considered. Faster players, as compared to slower players, showed a 30% higher foot-ball cadence (3.0 ± 0.1 vs. 2.3 ± 0.2 contacts · s^?1, P < 0.01); reduced CoM mediolateral (0.91 ± 0.05 vs. 1.14 ± 0.16 m, P < 0.05) and vertical (0.19 ± 0.01 vs. 0.25 ± 0.03 m, P < 0.05) RoMs; higher right stride cadence (+20%, P < 0.05) with lower variability (P < 0.05); reduced hip and knee flexion RoMs (P < 0.05). In conclusion, faster players are able to run with the ball through a shorter path in a more economical way. To effectively develop dribbling skill, coaches are encouraged to design specific practices where high stride frequency and narrow run trajectories are required.     

泉州市区"城中村"邻里关系的地理学分析

采用面向对象分析法OOA(object-oriented analysis)对影响泉州中心市区城中村的邻里关系进行详实的社会调查和探究,通过调研试图基本了解和掌握城中村居民的信息,对邻里关系特征进行描述和分析.文章通过对泉州中心市区中典型的“城中村”进行实地考察,借鉴国内外城中村改造的相关研究,从地理学、社会学等相关学科的角度出发进行分析思考;在此基础上就构建和谐的邻里关系进行探讨.     

高(大)分子──稀土配合物的发光应用研究进展

评述了高（大）分子──稀土配合物在发光应用研究方面的最新进展，研究了其发光特性及发光原理．指出了该类配合物在农用发光材料、防伪材料、荧光及彩色显示、温敏发光、导电发光、压致发光以及在生物、医学、聚合物结构形态、分子间（内）能量传递等方面的应用前景及发展趋势．     

滚翻垫球后“再后倒”现象的讨论

对滚翻垫球后“再后倒”现象进行理论分析 ,可找出出现问题的根源 ,以便在教学中解决这一问题     

教师教育实验教学示范中心建设创新的探索

温州大学教师教育实验教学示范中心建设过程中,从教师教育人才培养体系整体出发,以人才培养方案改革为抓手,以教师专业人才发展需求为导向,始终坚持创新技能与创新素养并重,基础与专业协调发展的思路。通过建立有效的实验教学示范中心管理运行机制,完善管理功能,形成实验教学改革的激励机制。通过建立先进的实验教学体系、内容和方法,构建"双核心"实验教学内容体系,"三层次"实验项目体系,突显"任务驱动"、"虚拟教学"、"协作学习"和"问题导向"等教学方法。     

生物学实验教学中心实验技术队伍建设

具体阐述武汉大学生物学实验教学中心在实验技术队伍建设中的一系列具体的举措:即推行继续教育和人才引进,优化学历和年龄结构;不断提高自身业务水平、优化职称结构;科学配置人员;实行招聘制和岗位流动制及探索符合自身特色的自治管理模式;在稳定实验技术队伍中推行人性化管理、提高福利待遇、推荐参政议政、鼓励继续学习和深造。     

粤港澳大湾区经济中心对粤北地区的经济辐射作用分析——以清远市为例

发挥经济中心对周边地区的经济辐射作用对一个区域的经济协同发展具有重要意义。粤北地区特别是清远市可以说是藏在粤港澳大湾区经济焦点下的盲点。借助地理距离优势,跨越发展鸿沟,使周边地区与粤港澳大湾区实现融合式互动和一体化发展,是一个具有重要研究价值的问题。可以将粤港澳大湾区及其周边地区作为一个城市群,描述和测算其基本发展现状及经济分布格局,探索经济辐射的必要性与可能的辐射路径。     

The biomechanical characteristics of high-performance endurance running

The biomechanical profile of high-level endurance runners may represent a useful model that could be used for developing training programmes designed to improve running style. This study, therefore, sought to compare the biomechanical characteristics of high-performance and recreational runners. Kinematic and kinetic measurements were taken during overground running from a cohort of 14 high-performance (8 male) and 14 recreational (8 male) runners, at four speeds ranging from 3.3 to 5.6?m?s^?1. Two-way ANOVA analysis was then used to explore group and speed effects and principal component analysis used to explore the interdependence of the tested variables. The data showed the high-performance runners to have a gait style characterised by an increased vertical velocity of the centre of mass and a flight time that was 11% longer than the recreational group. The high-performance group were also observed to adopt a forefoot strike pattern, to contact the ground with their foot closer to their body and to have a larger ankle moment. Importantly, although observed group differences were mostly independent of speed, the tested variables showed a high degree of interdependence suggesting an underlying unitary phenomenon. This is the first study to compare high-performance and recreational runners across a full range of kinematic and kinetic variables. The results suggest that high-performance runners maintain stride length with a prolonged aerial phase, rather than by landing with a more extended knee. These findings motivate future intervention studies that should investigate whether recreational runners could benefit from instruction to decrease shank inclination at foot contact.     

地方农林院校物理实验教学示范中心建设实践

从转变实验教学观念、建立科学实验教学体系、规范实验室管理、改善实验环境等方面介绍了浙江农林大学省级物理实验教学示范中心建设的实践.实验教学示范中心的建设过程贯穿“高等教育生态化”理念,构建并实施了以“三层四模”为核心、“两个平台”为栽体的生态化实验教学新体系;建设了由网络教学资源平台和网络管理服务平台组成的物理实验网络信息教学平台;创建了实验中心内部环境以及内外部环境关系生态化的实验教学环境.初步实践表明,示范中心的建设提高了实验教学效益,“拉动”了实验教学水平的提高,实现了教与学的双赢.