核心稳定性在人体运动中的作用

在体育运动中,核心的主要作用是稳定身体、是肌肉发力的基础,这一点日益得到公认。从跑步到投掷等各项体育运动中,稳定的核心是有效发挥人体生物力学功能的关键因素,从而使肌肉发力最大化并最大限度减小关节负荷。我们将核心肌群的功能理解为中枢神经系统预设的程序,这个程序整合局部的、单关节和多个关节上的肌群活动,在保持整体稳定的同时完成体育动作。近端的稳定性是远端灵活性的基础,在这个基础上可以建立从近端向远端的发力模式,并且可以通过肌群的协同作用力在完成远端动作的同时保护远端关节。评估动态核心能力是一项重要任务,其中包括对躯干特定功能和三维运动能力的评估。运动康复训练计划应该包括核心能力的重建,并且应该将核心视为远端肢体运动的基础。     

Close to you? Bias and precision in patent-based measures of technological proximity

Patent data have been widely used in research to characterize firms’ locations in technological or knowledge space, as well as the proximities among firms. Researchers have measured firms’ technological or knowledge proximities with a variety of measures based on patent data, including Euclidean distances (using the technological classifications listed on patents), and overlap in cited patents. Often research has employed only the first listed patent classification in measures of proximities. We explore the effects of using the first listed patent class as well as other methods to measure proximities. We point out that measures of proximity based on small numbers of patents are imprecisely measured random variables. Measures computed on samples with few patents or a single patent class generate both biased and imprecise measures of proximity. We discuss the implications of this for typical research questions employing measures of proximity, and explore the effects of larger sample sizes and coarser patent class breakdowns in mitigating these problems. Where possible, we suggest that researchers increase their sample sizes by aggregating years or using all of the listed patent classes on a patent, rather than just the first.     

How Experiments Begin: The Formation of Scientific Collaborations

Multi-organizational collaborations are increasingly important incontemporary science, but their formative processes have beenneglected by scholars in the social studies of science. Based onan examination of 53 collaborations in physics and relateddisciplines, we have found five types of formations.Collaborations that encountered greater difficulties in formingbecame more formal in their organization and management.     

Intelligence,creativity, and performance abilities of EMR pupils

This study examined the relationships between intelligence, creativity, and the performance of EMR pupils as rated by their teachers. For this group of 217 subjects, equally distributed among black, white, male, and female, creativity appears to be as important as intelligence, or more so, in determining their rated performance scores.     

The evolution of the operational earthquake forecasting community of practice: the L’Aquila communication crisis as a triggering event for organizational renewal

The scientific community of earthquake experts has long grappled with how to communicate earthquake probabilities successfully to non-scientific publics. Perhaps most central to their concern is the widely held belief that scientists can actually predict earthquakes when, in fact, they cannot. The potential consequences of this miscommunication problem were appallingly realized as a result of the 6 April 2009 earthquake in L’Aquila, Italy. Failed risk communication among scientists, a public official, and L’Aquila residents prior to the earthquake resulted in 309 deaths, 1500 injuries, and 65,000 people displaced from their homes, as well as the sentencing of six scientists and one public official to six years in prison for manslaughter. This paper examines how and why the L’Aquila Earthquake communication crisis ultimately redefined the international scientific earthquake community of practice and its discourse beyond that of community resilience to organizational learning and renewal.     

Effects of a minimalist shoe on running economy and 5-km running performance

The purpose of this study was to determine if minimalist shoes improve time trial performance of trained distance runners and if changes in running economy, shoe mass, stride length, stride rate and footfall pattern were related to any difference in performance. Twenty-six trained runners performed three 6-min sub-maximal treadmill runs at 11, 13 and 15 km·h^?1 in minimalist and conventional shoes while running economy, stride length, stride rate and footfall pattern were assessed. They then performed a 5-km time trial. In the minimalist shoe, runners completed the trial in less time (effect size 0.20 ± 0.12), were more economical during sub-maximal running (effect size 0.33 ± 0.14) and decreased stride length (effect size 0.22 ± 0.10) and increased stride rate (effect size 0.22 ± 0.11). All but one runner ran with a rearfoot footfall in the minimalist shoe. Improvements in time trial performance were associated with improvements in running economy at 15 km·h^?1 (r = 0.58), with 79% of the improved economy accounted for by reduced shoe mass (P < 0.05). The results suggest that running in minimalist shoes improves running economy and 5-km running performance.     

Local knowledge,global knowledge: The role of local language literacy for lifelong learning in rural African contexts

International Review of Education - Lifelong learning is an established concept in international education, with the discourse surrounding it implying that it is globally relevant. Nevertheless,...     

Special education students in the labour market: four case studies

ABSTRACT

This paper examines the employment status of 10 young men 10 years after leaving classes for the socially maladjusted. On the basis of their work careers, they were placed in one of 4 labour market sectors using the criteria (1) employed/unemployed at the time of the interview, and (2) history of long‐term/short‐term employment. Half of the young men were unemployed, 4 were working and 1 in prison. The large percentage of unemployed respondents was due to the exceptionally difficult economic situation prevailing in Finland at the time the interviews were carried out, as a result of which the national unemployment rate approached almost 20 per cent. Despite a lack of vocational education, all the young men but one had a positive attitude towards work, and those unemployed were actively seeking a job. There was almost no relation between the young men's school career and their work career, since those who had the longest‐lasting jobs were those young men who had had the most difficulties in school. When measured in terms of length of employment, the attachment of these young men to working life differed greatly: one had been for the entire postschool period (almost 10 years) in the service of the same employer, while another had had several jobs of a few months’ duration interspersed with periods of unemployment.