Match running performance and skill execution improves with age but not the number of disposals in young Australian footballers     

Paul B. Gastin  Christie Tangalos  Lorena Torres  Sam Robertson 《Journal of sports sciences》2017,35(24):2397-2404

This study investigated age-related differences in maturity, physical and functional characteristics and playing performance in youth Australian Football (AF). Young male players (n = 156) were recruited from 12 teams across 6 age groups (U10–U15) of a recreational AF club. All players were tested for body size, maturity and fitness. Player performance was assessed during a match in which disposals (kicks and handballs) and their effectiveness were coded from a video recording and match running performance measured using Global Positioning System. Significant main effects (P < 0.01) for age group were observed for age, years to peak height velocity, body mass, height, 20 m sprint, maximal speed over 20 m, vertical jump, 20 m multistage shuttle run, match distance, high-speed running distance, peak speed, number of effective disposals and percentage of effective disposals. Age-related differences in fitness characteristics (speed, lower body power and endurance) appeared to transfer to match running performance. The frequency in which players disposed of the football did not differ between age groups, however the effectiveness of each disposal (i.e., % effective disposals) improved with age. Match statistics, particularly those that evaluate skill execution outcome (i.e., effectiveness), are useful to assess performance and to track player development over time. Differences between age groups, and probably variability within age groups, are strongly associated with chronological age and maturity.  相似文献   

Interest in spatial activities predicts young children’s spatial ability development: A two-year longitudinal study     

《Contemporary educational psychology》2021

Studies have indicated the important impact of spatial abilities on science, technology, engineering, and mathematics (STEM) achievement. However, little is known about the predictors of individual differences in the growth trajectory of spatial ability. Children’s interest in learning activities plays a significant role in their ability development in literacy, math, and science. Therefore, the current study explored the role of children’s interest in spatial activities in their spatial ability development. We hypothesized that children’s interest in spatial activities would positively predict both the initial level and subsequent growth rate of spatial ability. The spatial ability of 197 Hong Kong preschool children (mean age = 52.72 months and SD = 3.30 months in the first wave of spatial ability assessment [Time 1]) was assessed four times over a two-year period, using a visual–spatial skills task. Their mothers ranked the children’s interest in various activities from 1 (most interested) to 13 (least interested) at Time 1. A growth curve analysis was performed to examine the relationships between interest in spatial activities at Time 1 and initial level and subsequent growth of spatial skills, controlling for parents’ expectations concerning spatial development, children’s interest in art activities, and demographics. The results showed that children’s interest in spatial activities significantly predicted their spatial ability growth (β = 0.252, p = .042), explaining 5.7% of the variance in growth, but was unrelated to the initial level of spatial skills. This finding highlights the importance of preserving and enhancing young children’s interest in spatial activities, among other activities, for the development of their spatial abilities.  相似文献   

劳动力有效人力资本构成对经济增长的影响--基于湖北省时间序列数据的分析     

汪曦  张智敏 《教育与经济》2015,(3)

本文从有效人力资本的视角出发,利用湖北省1978~2010年经济与教育方面的时间序列数据,分析了各级教育对经济发展实际影响的差异特征。在ADF检验的基础上,采用协整检验、VEC模型以及方差分解技术对各级教育对经济增长的实际贡献和动态影响进行了描述与解读。研究发现：有效人力资本对湖北省经济增长发挥了有限的促进作用,其具体影响在不同层级的有效人力资本之间存在明显的差异。要更好地发挥有效人力资本对经济增长的促进作用,一是要促进有效人力资本的深度开发,二是要提升高水平人力资本的积累水平。  相似文献   

中草药酵母硒硼对 AA 肉鸡生长性能的影响     

周先建  孙祯保  刘圣楠  任曼  靳二辉  金光明  顾有方  李升和 《安徽科技学院学报》2014,(5)

本文研究中草药酵母硒与微量元素硼联用对肉鸡生长性能的影响。1200羽1日龄健康 AA 肉鸡随机分为对照组和试验 I、II、III、IV 组,每组240羽;对照组饲喂玉米-豆粕型基础日粮,各试验组日粮设计为基础日粮﹢4%中草药酵母硒﹢硼（硼含量分别为0、5、10、15 mg / kg）,试验期42d。结果显示,试验 II~ IV 组21d 和42d 肉鸡平均体重和日增重均不同程度高于对照组和试验 I 组,其中21d 试验 II、IV 组和42d 试验 II、III 组肉鸡平均体重,1~21d 试验 II 组及22~42d 和1~42d 试验 II ~ IV 组平均日增重显著或极显著高于对照组（P <0.05或 P <0.001）;42d 试验 II、III 组肉鸡平均体重及22~42d 和1~42d 试验II、III 组平均日增重显著高于试验 I 组。各试验组不同日龄阶段料重比均不同程度低于对照组和试验 I组,其中22~42d 和1~42d（全期内）试验 II ~ IV 组肉鸡的料重比降低较为明显。试验结果表明,中草药酵母硒与微量元素硼联用对肉鸡的生长性能有明显促进作用,可明显提高肉鸡的平均体重、日增重和饲料转化率,并以添加0.4%中草药酵母硒和5~10 mg / kg 硼的联用效果最好。  相似文献   

基于少年儿童成长心理学的英语学习能力开发     

韦唐 《湖州职业技术学院学报》2014,12(3):91-94

在物质生活水平得到极大提高的今天,儿童却面临着精神生活十分贫瘠的现状。如何能在儿童的成长过程中满足他们的精神需求,并激发他们学习语言的潜能?如何树立前瞻而科学的教学理念?这些都是教育工作者需要探索的课题。结合心理学家杜·舒尔茨所著的《成长心理学》和西方心理学实验中的一些理论,论述了在少年儿童不同的成长阶段,英语教学者应以科学的心理学原理为依据,以正确的教学理念为依托,合理开发他们的英语学习能力,并帮助他们塑造健康的人格。  相似文献   

数字型创业企业的成长机制研究——基于双边规则多局域世界模型的仿真分析     

王宁 《科技管理研究》2021,(14)

在数字经济时代,以数据技术和数据资源为主要生产资料的数字型创业企业,成为推动经济快速发展的重要力量之一。本文从复杂网络理论出发,结合数字型创业企业成长的现实特征,提出“双边规则”的多局域世界网络模型,并采用Python编程的仿真分析方法,主要结论包括：（1）数字型创业企业所处的全局网络中,节点间边权的分布呈现“厚尾”的幂律分布特征,说明少数数字型创业企业具备极强的网络控制力,因而占据巨大多数资源,而大多数数字型创业企业具有较弱的网络控制能力,仅占有极少数资源;（2）其他条件不变,以技术为代表的适应性能力或以数据资源为代表的吸引力的提升,能够帮助数字型创业企业获得较强的网络影响力。相比适应性能力而言,具有较高吸引力的数字型创业企业在网络中的影响力更强;（3）对于整个复杂网络而言,数字型创业企业的适应性能力或吸引力提高的同时,网络中其他行为主体的网络影响力均能够得到增强。除此之外,数字型创业企业的适应性能力或吸引力的提升,使得网络中不同主体间的信息扩散效率得到提升,主体间的公平性也会有所提升。  相似文献   

全力打造渤海新区经济增长极之对策     

刘俊娥  ;张雪  ;段兴桥 《沧州师专学报》2014,(2):70-73

沧州市渤海新区在发展增长极的过程中机遇与问题并存,京津和环首都经济圈的发展趋势以及渤海新区自身的优势条件都为新区发展增长极提供了新的机遇。但同时也遇到一些诸如如何实现支柱产业真正大规模聚集等问题。解决此类问题的对策主要有:招商引资要做到快、准、稳,创新黄骅港港口建设和管理思路等。  相似文献   

论产业发展方向的一个历史性选择——产业融合     

王征 《黄河科技大学学报》2014,(4):41-43

当前,信息产业融合型的增长模式正在快速改变着社会经济的运行方式。产业融合正在加速产业结构的变动,也在推动产业转型升级。产业间的融合渗透促进了新兴业务的活跃爆发,为产业发展带来了一股全新的力量。应当以此为契机,培育新一代产业增长极,以产业融合推动战略性新兴产业发展。  相似文献   

Reflecting on their mission increases preservice teachers’ growth mindsets     

《Learning and Instruction》2023

When teachers believe that students' abilities are fixed, their students' motivation, well-being, and performance tend to suffer. While many interventions have been developed to reduce these so-called fixed mindsets in students and increase the belief that abilities are malleable (i.e., a growth mindset), there are no cost-effective, scalable interventions targeting teachers' mindsets. To address this need, we developed a brief intervention consisting of a reflection task in which teachers thought and wrote about their mission as educators. Two experiments with preservice teachers (total N = 576) revealed that this brief intervention increased their growth mindsets (meta-analytic d = 0.25). This increase did not dissipate over the course of a week (meta-analytic d = 0.26), suggesting the intervention's effects are not ephemeral. Although more work is needed to establish the robustness and generalizability of this intervention's effects, it may ultimately become a useful tool for teacher education programs.  相似文献   

“成长场”对集群企业成长的作用分析     

王国红  方明  邢蕊 《科学学与科学技术管理》2011,32(9)

集群中企业的成长不仅受到自身能力和相关企业及公共组织的影响,还与产业集群的属性有关,产业集群对企业成长的影响具有＂场效应＂的作用。将＂场思维＂引入到集群企业成长机制研究中,提出了影响集群企业成长的三种场力：基于组织间关系的场力、基于集成效应的场力和基于集成风险的场力;构建了基于成长场的集群企业成长模型,定量化解析了三种场力的构成和集群企业的成长机制。通过研究发现,三种场力的大小和集群企业的成长过程均与＂成长场＂场强、集成风险、组织质量、组织距离和组织嵌入度等要素有关,集群企业需要协调好各要素之间的关系,尽量增大企业在发展中所受到的正向场力作用,减小负向场力作用,从而实现企业的持续快速成长。  相似文献