Comparing the magnitude and direction of asymmetry during the squat,countermovement and drop jump tests in elite youth female soccer players

ABSTRACT

The aims of the present study were to provide an in-depth comparison of inter-limb asymmetry and determine how consistently asymmetry favours the same limb during different vertical jump tests. Eighteen elite female under-17 soccer players conducted unilateral squat jumps (SJ), countermovement jumps (CMJ) and drop jumps (DJ) on a portable force platform, with jump height, peak force, concentric impulse and peak power as common metrics across tests. For the magnitude of asymmetry, concentric impulse was significantly greater during the SJ test compared to CMJ (p = 0.019) and DJ (p = 0.003). No other significant differences in magnitude were present. For the direction of asymmetry, Kappa coefficients revealed fair to substantial levels of agreement between the SJ and CMJ (Kappa = 0.35 to 0.61) tests, but only slight to fair levels of agreement between the SJ and DJ (Kappa = ?0.26 to 0.18) and CMJ and DJ (Kappa = ?0.13 to 0.26) tests. These results highlight that the mean asymmetry value may be a poor indicator of true variability of between-limb differences in healthy athletes. The direction of asymmetry may provide a useful monitoring tool for practitioners in healthy athletes, when no obvious between-limb deficit exists.     

The effect of limb dominance on lower limb functional performance – a systematic review

Lower limb dominance (or lateral preference) could potentially effect functional performance. Clinicians are often asked to make judgements as to when a patient has sufficiently “recovered” from an injury, typically using strength and dynamic performance outcome measures. The primary purpose of this study was to systematically review the literature in relation to limb dominance within active adult populations and discuss some limitations to current methods and relate this to current clinical practice. A search of MEDLINE and CINAHL and EMBASE databases and reference lists of those articles identified was performed. Eleven articles were selected for meta-analysis. There was no statistical effect of limb dominance for any of the functional tests: isokinetic quadriceps and hamstring tests, hamstring:quadriceps ratios, single-leg hop for distance, single-leg vertical jump and vertical ground reaction force following a single-leg vertical jump. Pooled symmetry values varied from 94.6% to 99.6% across the tests, above the clinically accepted benchmark of 90% used in clinical practice. Although the results of this study must be used with discretion, asymmetries in the tasks described in this analysis should be viewed as undesirable and remedied accordingly. Further research is needed to quantify asymmetries, particularly in relation to sport-specific contexts.     

两性关系中的权力归属

现行的社会秩序体现了男性的意志、男性社会的意识形态特征。这种特征由性别地位、性别角色和性别气质构成。它们分别属于政治范畴 ,社会范畴 ,心理范畴 ,三者之间相互依赖 ,形成三体相连而又相互独立的独联体。男性认为女性是他者 ,他者的存在是威胁和危险。于是男性必须排除这种威胁和危险     

科研合作中机构间科研主导力及邻近性机理——以中国生物医学领域为例

在学科紧密相关和信息资源相融的当代,探究科研合作的影响因素成了诸多学者关注的话题。然而,现有研究将各种合作关系视同一律,即两人发表一篇合著文章,便形成合作关系;同时,大部分研究没有系统地研究多维邻近性的影响。为此本文提出了"科研主导力"的概念与测度,并从多维邻近性出发系统地分析科研合作的影响因素。本文基于Web of Science (WoS)上2013-2017年的生物医学(Life Sciences&Biomedicine)领域中国境内科研机构发表的论文数据,采用社会网络分析和引力模型,揭示了中国境内生物医学领域的科研主导网络的网络拓扑特征与多维邻近性机制,发现科研主导力两极分化严重,分散程度提高,互惠程度提高;主导机构(通信作者所在机构)和参与机构(非通信作者所在机构)的累积科研主导力显著促进科研主导力的扩散,且主导机构的促进作用大于参与机构;地理距离会阻碍科研主导力的扩散;认知背景相似度越高,社会关系越密切,越能形成科研主导关系;同样的制度环境、文化环境可以促进科研主导关系的形成。本文对全面理解多样化的科研合作模式、演化及其影响因素提供借鉴意义,研究科研主导力的相关方法可以推广到其他领域中。     

The mediating role of moral exclusion between authoritarianism and outgroup discrimination

It has been well-documented that right wing authoritarianism and social dominance orientation as two facets of the authoritarian personality differentially account for a variety of negative intergroup behaviors. Integrating the Dual Process Model (Duckitt, 2001), with the literature on “Moral exclusion” (e.g., Opotow, 1990; Tileagă, 2007) we investigated whether or not moral exclusion would mediate such a relationship. Employing survey data (N = 1015), collected from a representative Hungarian sample, we found that moral exclusion mediated the effects of both RWA and SDO on the negative behavioral intentions against Roma as well as Jewish minorities in Hungary. Moreover, we argued that the concept of moral exclusion should be interpreted not as a generalized tendency, but as a mechanism which can be stemmed from distinct social cognitive motivations.     

梅园节肢动物群落优势种分析

应用系统调查和能流量法分析了梅园节肢动物群落优势种,结果表明:不论数量和能流量分析,梅园节肢动物群落的主要害虫优势种均为朝鲜球坚蚧和桃蚜;而天敌优势种数量和能流量分析分别为黑缘红瓢虫、红点唇瓢虫和黑缘红瓢虫、草间小黑蛛.     

Threat and Prejudice against Syrian Refugees in Canada: Assessing the Moderating Effects of Multiculturalism,Interculturalism, and Assimilation

A survey experiment (N = 529) was used to test the moderating effects of intergroup ideologies (assimilation, multiculturalism, and interculturalism) on the relationship between social dominance orientation (SDO) and expressions of prejudice under conditions of intergroup threat. Moderated multiple regression analyses suggest a multicultural integration frame moderates the relationship between SDO and feelings toward Syrian refugees in Canada when the target outgroup is portrayed as a source of intergroup threat. This moderating effect was unique to the relationship between SDO and feelings toward Syrians and did not extend to other correlates of prejudice including beliefs in zero-sum group competition or a multicultural ideology, nor did it extend to more general measures of prejudice (i.e., attitudes toward immigrants or evaluations of intercultural contact). Findings suggest the prejudice-reducing effects of a multicultural integration narrative affect group evaluations and functions by targeting beliefs in social dominance, rather than zero-sum group competition or ideological support for cultural diversity. The results offer insights into the prejudice-reducing potential for two alternative integration narratives that are institutionalized in Canada.     

自媒体时代隐形资源与大学生思政教育的主导性

自媒体时代大学生思想政治教育的主导性受到挑战。正确认识和把握高校隐形教育资源的内涵及特点,充分挖掘高校隐形教育资源巨大的潜在价值,实现与自媒体的融合,是突破大学生思想政治教育困局,巩固其主导性的一条新路径。     

人体运动功能和肌肉损伤

人的一生是在维持着一定的身体姿势和重复完成各种动作的过程中度过的。在承受超过习惯负荷的工作以后所诱发的延迟性肌肉酸痛是由于工作停止以后肌肉收缩蛋白的降解、解聚强于组装、聚合的降解优势导致收缩结构改变或解体。经过休息、调整后续工作负荷,合成代谢逐渐加强而使结构自然恢复、酸痛随之消失。但若在收缩蛋白的降解优势的情况下,重复过度负荷将导致肌肉损伤,出现不能自然恢复的相对稳定的改变。我国传统医学中的阿是穴斜刺针法通过加强收缩蛋白的组装、合成,促进肌肉结构和功能恢复正常,因而对治疗慢性和急性肌肉损伤都有显著的疗效。肌肉损伤无论在体育锻炼、工作和生活中都是多发常见,但至今还没有受到医学界和全社会的关注。为了保证人们的健康成长、充分发挥人力资源在提高经济、发展生产中的作用,在努力工作时要特别注意劳逸结合,并使适度的体育锻炼成为每一个社会成员生活必需的组成部分,为此,应该在医学和体育院校开设肌肉损伤的病因和防治课程;在医院建立肌肉损伤专科门诊;在医学、体育、教育相关的院校和研究机构开展研究工作;进行相关的科普宣传等等。解决上述的问题涉及医疗、教育、劳动、体育等许多部门的协同工作和多年的努力,需要各级领导的支持和推动。     

基于随机优势与概率优势的风险型多属性决策方法

本文讨论属性值用概率分布函数描述的风险型多属性决策问题。首先,分析了利用随机优势描述偏好的局限性;其次,给出概率优势的概念,并得出了随机优势与概率优势在比较随机变量取值优劣方面具有互补性的结论;再次,针对风险型多属性决策问题,结合随机优势与概率优势共同描述方案在单个属性下的局部偏好,并利用赋值级别高于关系的思想集结得到总体偏好关系;最后给出了一个实例,计算结果表明:与文献中仅用随机优势描述偏好的方法相比,本文所给的决策方法的求解结果要好。