Weekday–weekend variations in mother-/father–child physical activity and screen time relationship: A cross-sectional study in a random sample of Czech families with 5- to 12-year-old children     

Dagmar Sigmundová  Petr Badura  Erik Sigmund  Jens Bucksch 《European Journal of Sport Science》2018,18(8):1158-1167

This study assessed the associations between these factors in a random sample of Czech families with preschool and school-aged children. A nationally representative sample comprised 185 families with preschool children and 649 families with school-aged children (dyads; both parents and child n?=?365, mother and child n?=?730, and father and child n?=?469). The participants wore Yamax Digiwalker SW-200 pedometers at least four weekdays and both weekend days and completed family logbooks (anthropometric parameters, daily step counts (SC), and screen time (ST)). When a parent (fathers at weekends and mothers both on weekdays and at weekends) achieved 10,000 SC per day, their children were also significantly (OR?=?2.93–6.06, 95% CI?=?2.02–9.26) more likely to meet the daily SC recommendation. On the contrary, the involvement of fathers in organized leisure-time PA reduced their children's odds of meeting the SC recommendation on weekdays (OR?=?0.53, 95% CI?=?0.31–0.89) and at weekends (OR?=?0.41, 95% CI?=?0.24–0.72). The excessive ST of parents at weekends reduced the odds of their children meeting the SC recommendation (mother–child dyads: OR?=?0.44, 95% CI?=?0.26–0.72; father–child dyads: OR?=?0.63, 95% CI?=?0.37–1.06). High levels of parents’ PA contribute to the achievement of the recommended daily PA in children on weekdays and at weekends. Excessive weekend ST of parents reduces their odds of their children achieving the recommended daily PA; however, the influence of parents’ PA on their children’s achieving the recommended daily PA is stronger than the inhibitory effect of ST.  相似文献   

Middle School Teachers’ Use of Mathematics to Make Sense of Student Solutions to Proportional Reasoning Problems     

Erik Jacobson  Joanne Lobato  Chandra H. Orrill 《International Journal of Science and Mathematics Education》2018,16(8):1541-1559

Mathematics teacher education aims to improve teachers’ use of mathematical knowledge to support teaching and learning, an aspect of pedagogical content knowledge (PCK). In this study, we interviewed teachers to understand how they used mathematics to make sense of student solutions to proportional reasoning problems. The larger purpose was to find accurate ways of categorizing teachers’ ability to do this vital aspect of teaching and thereby to inform assessment, teacher education, and professional development. We conjectured that teachers’ PCK for proportional reasoning could be reliably described in terms of attention to quantitative meanings in story problem contexts and in terms of understanding naïve forms of proportional reasoning. Instead, our findings reveal that individual teachers used a variety of means to make sense of (1) cognitively similar student solutions to different tasks and (2) mathematically related steps of a student solution within a single task. These findings illustrate the complexity of PCK for the topic of proportional reasoning and suggest the limits of what can be inferred about teacher knowledge from teachers’ evaluations of student solutions. We discuss implications for teacher education and assessment.  相似文献   

Effect of exercise and nasal splinting on static and dynamic measures of nasal airflow     

Erik W. Faria  Cindy Foster  Irvin E. Faria 《Journal of sports sciences》2013,31(4):255-261

The main aim of this study was to assess the separate and combined effects of exercise and nasal splinting on static and dynamic measures of nasal airflow. In a randomized crossover design, 12 healthy participants (6 men, 6 women) performed static and dynamic spirometric nasal airflow assessment tests, with or without nasal splinting (Breathe-Right?), before and after a maximal oxygen uptake (VO 2max ) treadmill test. At least 7 days later, the V O 2max and nasal airflow tests were repeated. The results showed that the measured variables were not significantly different with and without nasal splinting. We conclude that the absence of significantly enhanced nasal patency observed for nasal splinting and after exercise suggest that these factors have a minimal impact on nasal airflow volume and rate.  相似文献   

Performance Enhancement and Politicisation of High-Performance Sport: The West German ‘air clyster’ Affair of 1976     

Henk Erik Meier  Marcel Reinold 《国际体育史杂志》2013,30(12):1351-1373

While the politicisation of high-performance sport is perceived to represent one of the driving forces behind doping, we know not much how exactly the cold war in sports has affected sporting misconduct in western societies. Therefore, we propose here to distinguish between ideological and institutional politicisation and explicit and implicit acceptance of dubious practices. We apply our framework to analyse the West German ‘air clyster’ affair of 1976 in order to examine to what extent the politicisation of high-performance sport during the cold war affected the search for innovation in performance enhancement. We find that political pressure for improved competitiveness in West German sport had served to create a semi-autonomous high-performance sport sector in West Germany where blurred lines of accountability allowed questionable practices to prosper. While the public despised the use of questionable methods, sportive nationalism served to eclipse dubious practices. West German sport leaders adopted insofar a permissive attitude towards questionable practices as sporting misconduct was not sanctioned. Thus, our results strongly suggest that sport's politicisation during the cold war facilitated the search for performance-increasing methods in western societies.  相似文献   

Defining an Organizational Role in a Contested Field: The Evolution of UNESCO’s Approach to Physical Education     

Christina Uhlenbrock  Henk Erik Meier 《国际体育史杂志》2013,30(11):1130-1148

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When favourites fail: Tournament trophies as reward cues in tennis finals     

Erik Bijleveld  Ruud Custers  Henk Aarts 《Journal of sports sciences》2013,31(13):1463-1470

Abstract

In tournaments in various sports that feature one–on–one competition, the trophy is sometimes prominently displayed near the athletes during the final. Based on recent research on subtle reward cues, we propose that such trophies have the potential to induce choking under pressure in the match favourites, who are known to be most at risk. To test this idea, we analysed real-life tennis performance data (service performance and rally performance) from professional tournaments. While favourites generally outperformed underdogs during rallies, they did not do so in finals in which (a) large amounts of money were at stake and (b) a trophy was on display near the court. These findings support the idea that tournament trophies may distract favourites by continuously reminding them of what is at stake, and via that route may severely thwart their performance.  相似文献   

Dynamics of the martial arts high front kick     

Henrik S⊘rensen  Morten Zacho  Erik B. Simonsen  Poul Dyhre‐Poulsen  Klaus Klausen 《Journal of sports sciences》2013,31(6):483-495

Fast unloaded movements (i.e. striking, throwing and kicking) are typically performed in a proximo‐distal sequence, where initially high proximal segments accelerate while distal segments lag behind, after which proximal segments decelerate while distal segments accelerate. The aims of this study were to examine whether proximal segment deceleration is performed actively by antagonist muscles or is a passive consequence of distal segment movement, and whether distal segment acceleration is enhanced by proximal segment deceleration. Seventeen skilled taekwon‐do practitioners were filmed using a high‐speed camera while performing a high front kick. During kicking, EMG recordings were obtained from five major lower extremity muscles. Based on the kinematic data, inverse dynamics computations were performed yielding muscle moments and motion‐dependent moments. The results indicated that thigh deceleration was caused by motion‐dependent moments arising from lower leg motion and not by active deceleration. This was supported by the EMG recordings. Lower leg acceleration was caused partly by a knee extensor muscle moment and partly by a motion‐dependent moment arising from thigh angular velocity. Thus, lower leg acceleration was not enhanced by thigh deceleration. On the contrary, thigh deceleration, although not desirable, is unavoidable because of lower leg acceleration.  相似文献   

Who's Responsible for the Digital Divide? Public Perceptions and Policy Implications     

Dmitry Epstein  Erik C. Nisbet  Tarleton Gillespie 《The Information Society》2013,29(2):92-104

Addressing the reasons for—and the solutions to—the “digital divide” has been on the public agenda since the emergence of the Internet. However, the term has meant quite different things, depending on the audience and the context, and these competing interpretations may in fact orient toward different policy outcomes. The goals of this article are twofold. First, the authors unpack the term “digital divide” and examine how it has been deployed and interpreted across a range of academic and policy discourses. Second, through a framing experiment embedded within a nationally representative survey, the authors demonstrate how presenting respondents with two different conceptual frames of the digital divide may lead to different perceptions of who is most accountable for addressing the issue. From this, they discuss the dynamic relationship between the construction and communication of policy discourse and the public understanding of the digital divide, as well as implications for effective communication about the digital divide and information and communication technology policy to the general public.  相似文献   

The Debate     

Erik P. Bucy 《The Information Society》2013,29(5)

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Recollection of a mentor     

Hans Erik Wennberg 《TechTrends》2003,47(1):2-3

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