Postural stability,clicker reaction time and bow draw force predict performance in elite recurve archery

Recurve archery is an Olympic sport that requires extreme precision, upper body strength and endurance. The purpose of this research was to quantify how postural stability variables both pre- and post-arrow release, draw force, flight time, arrow length and clicker reaction time, collectively, impacted on the performance or scoring outcomes in elite recurve archery athletes. Thirty-nine elite-level recurve archers (23 male and 16 female; mean age?=?24.7?±?7.3 years) from four different countries volunteered to participate in this study prior to competing at a World Cup event. An AMTI force platform (1000Hz) was used to obtain centre of pressure (COP) measurements 1s prior to arrow release and 0.5s post-arrow release. High-speed footage (200Hz) allowed for calculation of arrow flight time and score. Results identified clicker reaction time, draw force and maximum sway speed as the variables that best predicted shot performance. Specifically, reduced clicker reaction time, greater bow draw force and reduced postural sway speed post-arrow release were predictors of higher scoring shots. It is suggested that future research should focus on investigating shoulder muscle tremors at full draw in relation to clicker reaction time, and the effect of upper body strength interventions (specifically targeting the musculature around the shoulder girdle) on performance in recurve archers.     

Editorial statement

Grounded in the interdisciplinary educational work of Cultural Studies, this paper examines the pedagogical potentials of narrative and performance for the teaching of writing as a mode of public discourse. Guided to address a wide readership, students engage in critical communication aimed at linking self inquiry and narrative discourse to the contextual analysis of the social. Drawing on research findings derived from the undergraduate teaching of cultural criticism as a genre of public writing at Lingnan University, Hong Kong, we look at how educational drama mediates the work of narrative and performative acts involving the young learner-writers and contributes to the shaping of a dialogic mode of address and communication, thus articulating the process and impact of writing to the public-oriented discourse in Cultural Studies education. In light of such acts in critical discourse and imagination targeted at the potential reader, we show how the young writers' own engagement with critical thinking and communication are opened up by drama-in-education adopted in the class, and argue how, in this sense, both writing and its learning process become effective stages in the making of the kind of cultural criticism we want to help students to learn.     

西方传教士对清末学习日本活动的引导和反应

清末时期,在华基督教传教士以日本为典范,宣扬“西学”对日本社会变革影响的言论,对中国当时学习日本活动的兴起产生了一定的引导作用。然而在运动开始之后,传教士又作出了消极的反应,担心日本对中国可能产生重要的政治影响。     

Cloning the Blairs: New Labour's programme for the re-socialization of working-class parents

In his speech to the Confederation of British Industry (CBI) in July 1999, the UK Secretary of State for Education, David Blunkett, set out New Labour's vision for a system of education in which there is ‘excellence for the many not just the few’. He outlined what is essentially a bi-focal strategy for achieving this vision. The first focus is on the education system itself, the structures and practices that New Labour believes need to be in place if schools and services are going to meet the needs of all children and not just a privileged minority. The second focus is on the need to promote ‘a culture of achievement’, as, according to Blunkett, the vision ‘depends on changing attitudes as well as the system itself’. This paper focuses on this second strategy, more specifically the government's attempts to change the attitudes of parents. It is argued that this strategy aims to eradicate class differences by reconstructing and transforming working-class parents into middle-class ones, that it represents possibly the most important and far-reaching aspect of New Labour's policy agenda, and that it has not so far received the attention it deserves. The paper is in two parts. The first part sets out what is involved in New Labour's programme of re-socialization and explores the mechanisms by which New Labour is attempting to universalize the values, attitudes and behaviour of a certain fraction of middle-class parents. The second part develops a critique of this programme.     

整理活动的生理效应

整理活动做为运动训练过程中一个重要的环节,已为许多教练员和运动员所认同,然而,也有许多教练员和运动员由于不完全了解它的生理机制以及给训练所带来的好处,引起足够的重视。本文旨在通过对整理活动的分析,阐述其对人体各器官的机能的影响,从而帮助教练员和运动员以及体育爱好者掌握和有效地运用这种方法,使它贯穿于训练和比赛之中,促进运动员疲劳的消除和机体的快速恢复。     

海派文学研究综述

文章对海派文学研究进行了系统回顾,重点介绍了20世纪30年代“京海论争”的情况和新时期以来海派文学研究的新进展,对研究现状、取得的成绩和尚待开拓的领域作了分析。     

Impact absorption of tennis shoe-surface combinations

The aim of this study was to investigate, for typical shoes and surfaces used in tennis, the relative role of the shoe and surface in providing cushioning during running. Five test surfaces ranging from concrete to artificial turf were selected, together with two shoe models. Impact absorbing ability was assessed mechanically using drop test procedures and biomechanically using peak magnitude and rate of loading of impact force and peak in-shoe pressure data at the lateral heel. Differences in biomechanical variables between shoe-surface combinations were identified using a two-way ANOVA (p < 0.05). Mechanical test results were found to rank the surfaces in the same order regardless of the shoe model, suggesting that the surface is influential in providing cushioning. However, for all mechanical and biomechanical (p < 0.05) variables representing impact absorbing ability, it was found that the difference between shoes was markedly greater than the differences between surfaces. The peak heel pressure data were found to rank the surfaces in the same order as the mechanical tests, while impact force data were not as sensitive to the changes in surface. Correlations between mechanical and biomechanical impact absorption highlighted the importance of testing the shoe-surface combination in mechanical tests, rather than the surface alone. In conclusion, mechanical testing of the shoe-surface combination was found to provide a strong predictor of the impact absorbing ability during running if pressure data were used. In addition, for typical shoe-surface combinations in tennis, the shoe was found to have more potential than the surface to influence impact loading during running. Finally, in-shoe pressure data were found to be more sensitive than force plate data to changes in material cushioning.     

利用平衡板测人体运动环节重量和重心位置方法的理论推导

人体运动环节重量和重心位置是运动生物力学定量计算与分析的基础材料,如何简便、迅速地计算出受试运动员的环节惯性参数一直是本学科中从未攻克过的难题。运用平衡板测人体重心的基本原理,通过让受试者在二维平衡板上移动四肢而改变环节重心位置,同时在不动环节上附加重量的方法推算出了人体总重心与各运动环节重心之间的关系,最终得出了各运动环节的重量与重心位置。这项研究是对人体环节重量与重心位置测量的突破性探索,具有深远的意义。     

PCR技术在法医生物学中的应用

遗传学认为,DNA是人体性状及遗传变异的物质基础,它是遗传信息的携带者.DNA决定着我们的肤色、性别、身高、健康状况等个体特征.每个人的DNA都是不完全一样的.在法医学上,往往需要鉴别现场留下的物证是否属于犯罪嫌疑人.传统的方法主要是通过指纹、脚印、唇纹、化学物质等物证进行核对,这在一些情况下能起到作用.然而,有时候犯罪分子相当狡猾,或者现场被破坏的很严重,根本找不到上述痕迹.但是在理论上,只要犯罪分子在现场留下血渍、精斑、头发、阴毛、唾液等,通过分析其中的DNA,仍可查获真凶.另外,也可通过分析在现场找到的死者的残留物(如毛发、牙齿、骨骼等)中所含的DNA,来验明他们的真实身份.以前由于这些物证中DNA的含量甚微,再加上无法排除在分析时受到的干扰,DNA分析还或多或少是一种幻想.直到1985年,诺贝尔奖获得者Kary mullis发明了聚合酶链反应(polymerasechain reaction,PCR).再加上1988年Saiki对PCR的重大改进,才使DNA分析在法医学领域的应用取得了惊人的突破.所谓PCR,就是通过特定的DNA序列作为引物,在酶的作用下,经过几十次循环,使目的DNA得以快速复制、扩增,从而得到足以进行检测和分析的目的DNA片段.目的DNA(或称模板DNA)就好象是“轮子”,引物好象有汽车的“方向”,酶好象是“(?)力