Variation and homogeneity in affective responses to physical activity of varying intensities: An alternative perspective on dose – response based on evolutionary considerations     

Panteleimon Ekkekakis  Eric E Hall  Steven J Petruzzello 《Journal of sports sciences》2013,31(5):477-500

A model for systematic changes in patterns of inter-individual variation in affective responses to physical activity of varying intensities is presented, as a conceptual alternative to the search for a global dose?–?response curve. It is theorized that trends towards universality will emerge in response to activities that are either generally adaptive, such as moderate walking, or generally maladaptive, such as strenuous running that requires anaerobic metabolism and precludes the maintenance of a physiological steady state. At the former intensity the dominant response will be pleasure, whereas at the latter intensity the dominant response will be displeasure. In contrast, affective responses will be highly variable, involving pleasure or displeasure, when the intensity of physical activity approximates the transition from aerobic to anaerobic metabolism, since activity performed at this intensity entails a trade-off between benefits and risks. Preliminary evidence in support of this model is presented, based on a reanalysis of data from a series of studies.  相似文献   

Do cross-sectional student assessment data make a reasonable proxy for longitudinal data?     

Mantz Yorke  Elena Zaitseva 《Assessment & Evaluation in Higher Education》2013,38(8):957-967

Student performance data from a post-92 university in the United Kingdom showed that, for a substantial minority of programmes, there was a general dip in marks between Years 1 and 2. Longitudinal and cross-sectional data were analysed in order to ascertain whether the latter (with its advantage of a more rapid production of results) would make an adequate proxy for the former: the analyses suggest that it can do. The article discusses a number of factors that have to be borne in mind, particularly if cross-sectional analyses are undertaken.  相似文献   

对高校社会体育专业人才培养的再思考     

方武  夏云建 《湖北体育科技》2014,(5):456-458

采用文献资料法、专家访谈法、对比研究等方法对目前高校社会体育专业人才培养现状进行梳理分析,指出高校社会体育专业人才人才培养和社会市场需求之间存在矛盾,导致社会体育专业毕业学生就业难、难就业的实际现状。建议高校社会体育专业人才培养需重新定位思考,打破千篇一律的人才培养方式,找准自己的培养特色和差异性,为高校社会体育专业发展打下坚实的基础。  相似文献   

Reduction in public speaking state anxiety during performance as a function of sensitization processes     

Chris R. Sawyer  Ralph R. Behnke 《Communication quarterly》2013,61(1):110-121

Recently, scholars have suggested that biological factors, such as temperament, influence human social behavior, particularly in the formation of traits, such as communication apprehension. Despite progress in this area, the relationship between temperament and states, such as speech anxiety, remains unclear. Theories of temperament predict that the rate at which subjects habituate to stress varies inversely with the degree to which they are sensitized during initial confrontation with stress‐producing stimuli. The inverse relationship between habituation and sensitization, in the context of public speaking state anxiety, is examined in this report. In two separate studies, using both physiological and psychological measures of state anxiety, the inverse relationship between sensitization and habituation was confirmed. Specifically, sensitization accounted for 69.1% and 50.3% of the variance in physiological and psychological habituation, respectively.  相似文献   

Survey on skin aging status and related influential factors in Southeast China     

Yi-na Wang  Hong Fang  Wei-fang Zhu 《Journal of Zhejiang University. Science. B》2009,10(1):57-66

Objective: To investigate cutaneous aging patterns of residents in Hangzhou, Zhejiang, China, and their contributing 2004. Results: Facial wrinkling first occurred at 21 years of age and skin elasticity began to lose at 22 years of age. In middle-aged and old people, facial wrinkling and looseness escalated with the increase of ultraviolet (UV)-exposure time, indicating the ac-celerating effect of a higher accumulative dose of UV radiation on skin aging. Only Fitzpatrick types Ⅱ, Ⅲ and Ⅳ were found in the skin phototypes of residents in Hangzhou area, and Fitzpatrick type Ⅱ seemed to be much more subject to severe wrinkling, elasticity destruction and skin tumors than types Ⅲ and Ⅳ. The oily skin was more protected against wrinkling and facial looseness than dry skin. However, as to concomitant cutaneous diseases, no difference was found among different skin types. Conclusion: Age, solar-exposure time, Fitzpatrick type and skin type are the associated forces in promoting skin aging, and emotional factor seems to be another independent risk factor. The age of 49 years and 2 h/d of solar-exposure time seem to be the turning points responsible for dramatic changes of cutaneous appearance in the process of skin aging in Southeast China.  相似文献   

蔬菜出口产地的农药使用行为及其对农民健康的影响——来自山东省莱阳、莱州和安丘三市的调研证据   总被引：4，自引：0，他引：4  

王志刚  吕冰 《中国软科学》2009,(11)

近年来,蔬菜的农药残留问题日益成为食品安全中备受关注的焦点.尽管国内外学者对此已有一定研究.但针对蔬菜出口产地的农药使用行为及其对农民健康影响方面的实证研究却相当缺乏.本文根据在山东省取得的调研数据,深入研究了蔬菜出口产地的农药使用行为及其对农民健康的危害.结果表明,农民在使用农药的过程中存在着未能严格按照标签对农药进行稀释等一系列不规范的使用行为;而且不规范地使用农药和缺乏相应的保护措施对农民的整体健康造成了不可忽视的负面影响,其中是否采取保护措施对农民的皮肤健康有着显著的影响;喷洒次数对农民的呼吸系统具有显著的负面影响.在此基础上,本文提出了加大力度宣传正确使用农药的方法以及强化对农药使用的监控措施等相关政策建议.  相似文献   

The role of knowledge base homogeneity in learning from strategic alliances     

Annapoornima M. Subramanian  Wang Bo  Chai Kah-Hin 《Research Policy》2018,47(1):158-168

Strategic alliances are important channels for interfirm learning, especially for small firms that are resource constrained. Of the several alliance attributes, technological distance between partners (measured as the distance between partners’ innovative outcomes) is shown to have a significant influence on the learning benefits from strategic alliances. Drawing upon the theory of recombination, our study argues that the influence of technological distance on learning is best understood by not only measuring the distance between innovative outcomes, but by also taking into consideration the knowledge elements underlying the innovative outcomes. We develop a concept of knowledge base homogeneity that captures the extent to which the innovative outcomes of partnering firms draw upon similar sets of knowledge elements. Using patent and alliance data from 201 small biotechnology firms during the period 1996–2010, we confirm that the technological distance has an inverted u-shaped relationship on interfirm learning. We further demonstrate that this u-shaped relationship is moderated by the knowledge base homogeneity between partners, such that benefits of technological distance are enhanced and the costs of technological distance are mitigated when the knowledge base homogeneity between alliance partners is high. The results have important implications for interfirm learning, especially in the context of small firms that are limited in their knowledge stocks.  相似文献   

War-exposed newcomer adolescent immigrants facing daily life stressors in the United States     

《Int J Intercult Relat》2017

For adolescents new to the United States, the experience of war and acculturative stressors may play complex roles during early stages of adjustment to a new culture and country. The overall purpose of this study was to deepen understanding of the experiences of adolescents who are new to the United States, also called “newcomers”, through the examination of pre-migration war exposure and post-migration acculturative stressors as predictors of psychosocial adjustment and academic achievement. The study sample included newcomer immigrant and refugee youth (N = 184) with an average of 3.5 years in the United States. Triangulated data were collected from youth, teachers, and official school records. Results indicated that the participants who were exposed to war (N = 57) experienced more self-reported and teacher-reported anxiety, more self-reported conduct problems, and had lower academic achievement than participants who had not been exposed to war. Acculturative stressors also predicted more self-reported anxiety, conduct problems, and lower academic achievement, but only for those adolescents without war exposure, suggesting that exposure to traumatic events like war may change newcomer adolescents’ response to acculturative stressors. This may be related to the development of coping or growth that follows after trauma, which enable youth to navigate other life challenges. Understanding potential risk and resilience associated with war exposure among newly arrived students can assist clinicians, educators, and researchers in creating solutions to difficulties in psychosocial adjustment and academic performance.  相似文献   

"主流化"与"市民化"的困惑——都市报发展的艰难抉择     

黄海燕 《宜春学院学报》2007,29(3):184-188

针对中国都市报在当下面临的生存与发展困惑,本文试图通过对都市报发展的历史性观照,揭示问题出现的背景,从中分析造成都市报艰难抉择的原因,并提出对策。  相似文献   

光固化成型中曝光时间对成型质量的影响     

吴懋亮  方明伦  胡庆夕  戴春祥  卢秉恒 《上海大学学报(英文版)》2004,8(Z1)

A novel stereolithgraphy system with conventional UV light as a light source uses the 2D worktable as moving components, whose characteristics determine the accuracy of the prototyping parts. Many factors including mass of the worktable, elasticity and damp coefficients, speed and acceleration affect the non-uniform exposure time of the resin, and eventually influence the cured line shape and the curing accuracy. A light shuttle is used to eliminate the cure errors, greatly improving accuracy of the parts.  相似文献