Social correlates of sedentary behavior in young people:The UP&DOWN study

Purpose:The aim of the present study was to analyze the associations of youths' sedentary behavior(SB) with parents' and siblings' SB and physical activity(PA),as well as the associations of youths' coparticipation with parents,siblings,and friends in PA and SB with youths' SB.Methods:The sample consisted of 1543 youths(12.02±2.51 years;788 boys) enrolled in the baseline cohort of the UP&DOWN study.SB was assessed by accelerometry and questionnaire.Participants reported the time spent by their parents and siblings watching television,playing videogames,surfing the Internet,sitting/resting,and doing PA.Further,participants reported coparticipation with parents,siblings,and friends in these activities.Linear mixed models,including school and city as random effects,were performed.Results:Parents' television time was positively associated with youths' screen-based SB.Coparticipation with friends in playing videogames(in boys) and in surfing the Internet(in girls) showed a positive association with screen-based SB and a negative association with educational-based SB.Moreover,coparticipation with siblings and friends in PA was inversely associated with accelerometer-based SB in boys and girls.Conclusion:Our results emphasize the important role of social modeling in the development of sedentary lifestyles in youths.Interventions aimed at reducing health risk behaviors in youths could be more effective if they are oriented from a social perspective that involves their families and networks of their closest friends.     

磷酯酰肌醇3激酶在骨骼肌中的调节以及运动对它的影响

在骨骼肌中磷酯酰肌醇3激酶(PI3K)以异二聚体形态存在.它以及它下游的靶目标和胰岛素受体底物(IRS1,2)一起在胰岛素信号转导通路中发挥重要作用,并参与了胰岛素刺激的葡萄糖转运和GLUT-4转移;不同强度运动以及运动时间对骨骼肌中PI3K有着不同的作用,这也和胰岛素的调节有关.     

The impact of government-supported participative loans on the growth of entrepreneurial ventures

We study the employment and sales growth of entrepreneurial ventures that have received a government-sponsored participative loan (PL), a hybrid form of financing between debt and equity. We use propensity-score matching (PSM) and instrumental variable analysis (2SLS) to study a sample of 512 entrepreneurial ventures that received a PL from a Spanish government agency between 2005 and 2011. We find evidence that PLs significantly boosted their beneficiaries’ employment and sales. In the two years following loan issuance, a 1-million-Euro PL generated an increase in average employment of between 12.1 (PSM) and 14.7 (2SLS) units and an increase in sales of between 1.09 and 1.97 million Euro relative to the average for the two years prior to loan issuance. The effect is larger for high-tech, young and small entrepreneurial ventures and for those that received a PL during the global financial crisis. The effect on growth is significant and stable, and PLs increase their beneficiaries’ annual growth by 10.6% for employment and by 18.0% for sales. We do not find evidence of industry or regional spillovers, nor do we find differences in the probability of survival of PL beneficiaries after we control for their characteristics.     

体育教学与人的社会化

本文从心理学、社会学、社会心理学的角度 ,论述了体育教学对人的社会化的作用 ,认为不管是体育教学的内容 ,还是体育教学自身的特点以及体育教学的特殊群体 ,对人的社会化过程中的掌握生活技能、培养社会角色、学习社会文化、促进个性形成都起着积极的作用。     

论我国田径英语裁判员的培养

本文就我国培养田径英语裁判员的意义、我国田径英语裁判员应具备的素质、和我国培养田径英语裁判员的策略进行了详尽的论述。     

Replication crisis or an opportunity to improve scientific production?

Science is undergoing a crisis that has been referred to, since the early 21st century, as a crisis of confidence and a crisis of replication. This article reviews questions pertaining to the replication crisis; questions addressing the quality and credibility of the sciences; specifically, questions linked to what are known as false positives, null results, and questionable research practices (p-hacking, harking, cherry-picking). As an outcome of our review and analysis, a set of recommendations to strengthen the elaboration of reliable and valid research studies is provided. Changes are needed in order to foment meta-research, open science practices and replication studies; notably, changes are needed in the instruction of research methods; in the use and interpretation of statistical data, as well as in research culture in general. We conclude that the replication crisis presents an opportunity to improve research practices and the quality of scientific production in all fields of research, including research in education.     

Black boxes in analytical chemistry： University students misconceptions of instrumental analysis

Misconceptions of chemistry and chemical engineering university students concerning instrumental analysis have been established from coordinated tests, tutorial interviews and laboratory lessons. Misconceptions can be divided into： （1） formal, involving specific concepts and formulations within the general frame of chemistry; （2） operational/topical, dealing with specific capabilities, problems and operations in chemistry; （3） methodological, associated to peculiar methods of analytical chemistry and data treatment; and （4） social, regarding the relation of analytical data with the social frame. Such misconceptions define a non-structured view of analytical methods, procedures and protocols related with analytical instrumentation. Instruments are frequently viewed as an autonomous, error-free black box providing non-structured data with no need of calibration or control, whereas weak relationships are established between data and aims along the analytical process.     

Metabolic impact of a soccer match on female players

The aim of this study was to examine the metabolic effect of a female soccer match in elite and sub-elite teams. Blood samples were taken (24 h before, immediately after and 18 h after official soccer matches) to determine haematological, electrolytic and hormonal variables, as well as the levels of cell damage and oxidative stress in 14 elite and 14 sub-elite players. Our results show increases in white blood cell count (P < 0.001) and the percentage of neutrophils (P < 0.001), and decreases in the percentage of lymphocytes (P < 0.05), eosinophils (P < 0.001), monocytes (P < 0.001) and basophils (P < 0.05) immediately post-match. Increases were also found in lactate dehydrogenase activity (P < 0.001), uric acid (P < 0.001), albumin (P < 0.001), total antioxidant status (P < 0.001) and free testosterone levels (P < 0.01). Creatine kinase activity significantly increased 18 h post-match (P < 0.01) and the concentrations of several ions, glucose and proteins were found to be altered immediately post-match. Overall, our results show that playing a soccer match exerts specific metabolic effects on female players, resulting in muscle damage, oxidative stress and biochemical and hormonal variations. On the basis of some interesting correlations, we also suggest that exercise-induced cell breakdown may enhance antioxidant capacity of the soccer players.     

Study of context influence on classifiers trained under different video-document representations

The problem of content-based video retrieval continues to pose a challenge to the research community, the performance of video retrieval systems being low due to the semantic gap. In this paper we consider whether taking advantage of context can aid the video retrieval process by making the prediction of relevance easier, i.e. if it is easier for a classification system to predict the relevance of a video shot under a given context, then that context has potential in also improving retrieval, since the underlying features better differentiate relevant from non-relevant video shots. We use an operational definition of context, where datasets can be split into disjoint sub-collections which reflect a particular context. Contexts considered include task difficulty and user expertise, among others. In the classification process, four main types of features are used to represent video-shots: conventional low-level visual features representing physical properties of the video shots, behavioral features which are based on user interaction with the video shots, and two different bag-of-words features obtained from the Automatic Speech Recognition from the audio of the video.