Differences in the utilisation of active power in squat and countermovement jumps     

Damián Ferraro  Gabriel Fábrica 《European Journal of Sport Science》2017,17(6):673-680

The aim of this article was to understand how active power is used in squat and countermovement jumps. A simple empirical model comprising a mass, a spring, an active element and a damper, together with an optimisation principle, was used to identify the mechanical factors that maximise performance of jumps without countermovement (squat jumps, SJ) and with countermovement (CMJ). Twelve amateur volleyball players performed SJ from two initial positions and CMJ with two degrees of counterbalancing, while kinematic data were collected (jump height, push-off duration and position of the centre of mass). The model adjusted well to real data of SJ through all the impulse phase, and slightly less adequately at the end of this phase for CMJ. Nevertheless, it provides a satisfactory explanation for the generation and utilisation of active power for both type of jumps. On average, the estimated power of the active elements, the spring, and the damper were greater in the SJ. Based upon the result obtained with this model, we suggest that active power is best evaluated with SJ. The reason for this is that, during this kind of jump, the elements associated with the damper consume much of the energy produced by the active elements. The participation of the elements that consume the energy generated by the active elements is less in CMJ than in SJ, allowing for a better utilisation of this energy. In this way it is possible to achieve a better performance in CMJ with less active power.  相似文献   

Sport disciplines,types of sports,and waist circumference in young adulthood – a population-based twin study     

Mirva Rottensteiner  Sara Mäkelä  Leonie H. Bogl  Timo Törmäkangas  Jaakko Kaprio  Urho M. Kujala 《European Journal of Sport Science》2017,17(9):1184-1193

Purpose: The benefits of physical activity (PA) in preventing abdominal obesity are well recognized, but the role of different sport disciplines remains open. We aimed, therefore, to investigate how participation in different sport disciplines, and the number and types of sports engaged in are associated with waist circumference (WC) in young adulthood. Methods: This population-based cohort study comprised 4027 Finnish twin individuals (1874 men), with a mean age of 34 y (32–37), who answered a survey, including self-measured WC. We extracted the number and identified the types (aerobic, power, and mixed) of the different sport disciplines respondents reported participating in. Results: The number of sport disciplines participated in was inversely associated with WC, the linear decrease averaging 1.38?cm (95% CI 1.10–1.65) per each additional sport discipline. The result persisted after adjustment for the main covariates, such as volume of PA and diet quality. Among dizygotic twin pairs discordant for sports participation (0–2 vs. 5 or more disciplines), the mean within-pair difference in WC was 4.8?cm (95% CI 0.4–9.1) for men and 11.2?cm (95% CI 4.4–18.0) for women; among discordant monozygotic pairs, no differences were observed. In men, all three types of sports were individually associated with smaller WC, while in women, only mixed and power sports showed this association. Conclusions: Participation in several sport disciplines and sport types was associated with smaller WC among young adults in their mid-30s. Shared genetic background may explain some of the associations.  相似文献   

Rome's World: The Peutinger Map Reconsidered     

Emilia Mataix Ferrándiz 《Al-Masaq: Islam & the Medieval Mediterranean》2017,29(1):84-86

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Evidence for data missing at random in youth physical activity monitoring research     

P. F. Saint-Maurice  Y. Kim  G. J. Welk 《Journal of sports sciences》2017,35(5):484-490

This study examined whether or not activity monitor data collected as part of a typical 7-day physical activity (PA) measurement protocol can be expected to be missing at random. A total of 315 participants (9–18 years) each wore a SenseWear Armband monitor for 7 consecutive days. Participants were classified as “compliant” (86 boys and 124 girls) if they had recorded accelerometer data during 70% or more of the predefined awake time (7 AM–10 PM) on four different days; and “non-compliant” (44 boys and 51 girls) when not meeting these criteria. Linear mixed models were used to examine differences in energy expenditure (EE) levels by compliance across 10 different time periods. The results indicated that non-compliant girls were older (13.4 ± 2.9 vs. 12.2 ± 2.5) and taller (156.8 ± 10.3 vs. 152.8 ± 11.3) than their same gender compliant peers (P < .05). Comparisons of EE rates at segmented portions of the day revealed no differences between compliant and non-compliant groups (P ≥ .05). Differences in EE ranged from ?0.32 kcal · kg^?1 · h^?1 (before school time) to 0.62 kcal · kg^?1 · h^?1 (physical education class) in boys and ?0.39 kcal · kg^?1 · h^?1 (transportation from school) to 0.37 kcal · kg^?1 · hour^?1 (recess) in girls. The results showed that compliant and non-compliant individuals differed in a few demographic characteristics but exhibited similar activity patterns. This suggests that data were considered to be missing at random, but additional work is needed to confirm this observation in a representative sample of children using other types of activity monitors and protocols.  相似文献   

Effectiveness of physical education to promote motor competence in primary school children     

Vítor P. Lopes  David F. Stodden  Luis P. Rodrigues 《Physical Education & Sport Pedagogy》2017,22(6):589-602

Background: Motor skill (MS) competence is an important contributing factor for healthy development.

Purpose: The goal was to test the effectiveness of primary school physical education (PE) on MS and physical fitness (PF) development.

Methods: Three classes (n?=?60, aged 9.0?±?0.9) were randomly assigned to three diverse conditions during a school year: two PE lessons/week (PE-2), three PE lessons/week (PE-3), and no PE lessons control group (CG). BMI, skinfolds, PF (9-min run/walk, sit-up, modified pull-ups), gymnastics, soccer, handball, basketball and track-and-field skills were evaluated. Effect sizes (d) were reported as magnitude of change.

Results: Skinfolds significantly increased only in CG (d?=?1.21). PF composite z-scores improved in PE-3 (d?=?0.61), but decreased in PE-2 (d?=?0.57), and had no changes in CG. Statistically significant improvement was verified in gymnastics and handball skills in both experimental groups (gymnastic: d?=?2.95 and d?=?2.61 for PE-3 and PE-2, respectively; handball: d?=?1.87 and d?=?0.57 for PE-3 and PE-2, respectively), and no changes were seen in CG. In soccer, there were improvements only in the PE-3 (d?=?0.55), and in basketball only in PE-2 (d?=?0.46). There were no changes in any group for track-and-field skills.

Conclusions: PE programs can effectively promote PF and MS development.  相似文献   

Originalism in the Classroom     

David F. Forte 《Academic Questions》2011,24(2):137-156

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How do Higher Education Institutions Enhance their Financial Autonomy? Examples from Finnish Polytechnics     

Vuokko Kohtamäki 《Higher Education Quarterly》2011,65(2):164-185

Numerous studies have addressed how state authorities and public funding bodies control, regulate, steer, supervise or oversee higher education institutions. There are fewer studies on how higher education institutions respond to the actions of the mentioned authorities. States have aimed at increasing the autonomy of higher education institutions. At the same time institutions are expected to generate social benefits and economic growth. There is an endless tension between a policy that will strengthen the autonomy and simultaneously retain a space for state steering. The Finnish polytechnic and university sectors have very different origins from which their financial autonomy takes its shape. This article sheds light on how six Finnish polytechnics aspire to enhance their financial autonomy. The polytechnics operate under two separate steering systems, the state and local owners, and both of these actors exercise their own steering. This article shows that polytechnics are willing and able to enhance their financial autonomy. They calculate their advantages and habitually engage with the Ministry of Education or their owners depending on the case in question. The financial autonomy of polytechnics does not culminate in a form of diversified funding sources, but as balancing between the two masters on whose resources they are heavily dependent.  相似文献   

The entrepreneurial university and academic discourses: The meta‐synthesis of Higher Education articles     

Baris Uslu  Alper Calikoglu  F. Nevra Seggie  Steven H. Seggie 《Higher Education Quarterly》2019,73(3):285-311

The innovative teaching, knowledge and technology production and societal service activities of academics are largely discussed within the entrepreneurial university discourse in Higher Education journals. Therefore, this research focuses on a meta‐synthesis of Higher Education articles to better understand the concepts of the entrepreneurial university and entrepreneurial academic. After the systematic elimination based on keywords and titles, 25 articles have been selected from the top 10 Higher Education journals in the SCImago Journal Rankings. Content analysis was performed on these articles to highlight the common operational areas in entrepreneurial universities and activities of entrepreneurial academics. The meta‐synthesis shows that, both for universities and academics, entrepreneurship is overwhelmingly characterised by the commercialisation of scholarly activities that enrich institutional income revenue as well as academics’ personal income. However, such an approach can distance universities from their mission of public good; so Higher Education administrators should create mechanisms that would allow both to take place in a balanced way.  相似文献   

Strength,Weakness, Opportunity,Threat (SWOT) Analysis of the Adaptations to Anatomical Education in the United Kingdom and Republic of Ireland in Response to the Covid-19 Pandemic     

Georga J. Longhurst  Danya M. Stone  Kate Dulohery  Deirdre Scully  Thomas Campbell  Claire F. Smith 《Anatomical sciences education》2020,13(3):301-311

The Covid-19 pandemic has driven the fastest changes to higher education across the globe, necessitated by social distancing measures preventing face-to-face teaching. This has led to an almost immediate switch to distance learning by higher education institutions. Anatomy faces some unique challenges. Intrinsically, anatomy is a three-dimensional subject that requires a sound understanding of the relationships between structures, often achieved by the study of human cadaveric material, models, and virtual resources. This study sought to identify the approaches taken in the United Kingdom and Republic of Ireland to deliver anatomical education through online means. Data were collected from 14 different universities in the United Kingdom and Republic of Ireland and compared adopting a thematic analysis approach. Once themes were generated, they were collectively brought together using a strength, weakness, opportunity, threat (SWOT) analysis. Key themes included the opportunity to develop new online resources and the chance to engage in new academic collaborations. Academics frequently mentioned the challenge that time constrains could place on the quality and effectiveness of these resources; especially as in many cases the aim of these resources was to compensate for a lack of exposure to cadaveric exposure. Comparisons of the actions taken by multiple higher education institutions reveal the ways that academics have tried to balance this demand. Discussions will facilitate decisions being made by higher education institutions regarding adapting the curriculum and assessment methods in anatomy.  相似文献   

Not Such Nature     

Hilton F. Japyassú 《Science & Education》2015,24(9-10):1271-1283

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