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901.
The recent migration of 65,000 children across the southwestern border, coupled with allegations of abuse by the U.S. Border Patrol, enables the investigation of an overlooked immigrant category: the unaccompanied youth migrant. Analyzing audience responses to news reports of the abuse, we find that established disparaging immigrant tropes apply, describing the children as an economic burden, disease carriers, and offspring of irresponsible families. We uncover two new themes: Youth migrants are channels whereby criminals may infiltrate the U.S., and manipulate legal authorities to remain in the U.S. Finally, we demonstrate how global compassion is strategically deployed to qualify harsh retaliatory measures.  相似文献   
902.
Brain injury research in sport employs a variety of physical models equipped with accelerometers. These acceleration signals are commonly processed using filters. The purpose of this research was to determine the effect of applying filters with different cutoff frequencies to the acceleration signals used as input for finite element modeling of the brain. Signals were generated from reconstructions of concussion events from American football and ice hockey in the laboratory using a Hybrid III headform. The resulting acceleration signals were used as input for the University College Dublin Brain Trauma Model after being processed with filters. The results indicated that using a filter with a cutoff of 300 Hz or higher had little effect on the resulting strain measures. In some cases there was some effect of the filters on the peak linear (8–30g) and rotational measures (1000–4000 rad/s2), but little effect on the finite element strain result (approximately 2–6 %). The short duration and high magnitude accelerations, such as the puck impact, were most affected by the cutoff frequency of different filters.  相似文献   
903.
The purpose of this study was to compare the validity and reliability of three short physical activity self-report instruments to determine their potential for use with university student populations. The participants (N = 155; 44.5% male; 22.9 ± 5.13 years) wore an accelerometer for 9 consecutive days and completed a single-item measure, the a brief two item measure and the International Physical Activity Questionnaire—Short Form questionnaires on day 1 and 9. Correlations between self-reported and accelerometer derived moderate-to-vigorous physical activity levels were moderate for the International Physical Activity Questionnaire—Short Form, while poor for the single-item measure and the a brief two item measure. The agreement level was high with the International Physical Activity Questionnaire—Short Form (77.4%) and moderate for both the single-item measure (45.2 %) and a brief two item measure (44.5 %). The intraclass correlations between the two administrations were moderate to strong across all measures (0.52–0.70) in 133 participants. The International Physical Activity Questionnaire—Short Form is the most suitable of these three self-report instruments for use with this population due to higher correlations and levels of agreement with accelerometry.  相似文献   
904.
The present study describes the development and validation of an instrument to measure volition in the exercise context. Volition describes an individual’s self-regulatory mental processes that are responsible for taking and maintaining a desirable action (e.g., exercising regularly). The scale structure was developed in an exploratory factor analysis which resulted in a reliable structure of the following six factors: Volitional Inhibition—Reasons, Volitional Inhibition—Postponing Training, Volitional Facilitation—Self-Confidence, Volitional Inhibition—Unrelated Thoughts, Volitional Inhibition—Approval From Others, and Volitional Facilitation—Coping with Failure. A sound theoretical explanation for these six factors is based on the Personal System Interaction Theory. This six-factor structure was also confirmed in a new sample in a confirmatory factor analysis, delivering an 18-item questionnaire with strong model fit and good internal consistency. In addition, the Volition in Exercise Questionnaire showed convergent validity because it was able to predict exercise participation. It showed incremental validity by explaining additional variance to the Sport Motivation Scale’s well-established predictors of exercise participation.  相似文献   
905.
This study aimed to analyse the effects of a simulated Brazilian jiu-jitsu (BJJ) tournament on vertical jump performance, grip strength test and perceived effort responses. 22 male BJJ athletes participated in a simulated tournament consisting of three 7 min matches separated by 14 min of rest. Kimono grip strength test (KGST), counter movement jump (CMJ) and rate of perceived exertion (RPE) were measured before and after each match, while RPE of specific areas was assessed after three matches. ANOVA for repeated measures was used to compare strength parameters after each match with the level of significance set at 5%. The key results showed a significant decrease of jump height (p = 0.001) and net vertical impulse in the CMJ (p = 0.031), as well as a reduction of the number of reps in the KGST (p < 0.001). A significant increase of RPE was found throughout the matches (p < 0.001). Considering the RPE in specific areas, no differences were observed between the upper and lower body (p = 0.743). We conclude that the BJJ simulated tournament generated a decrease of performance in both upper and lower limbs and provoked a progressive increase in the effort perception over the matches.  相似文献   
906.
The forward skating start is a fundamental skill for male and female ice hockey players. However, performance differences by athlete’s sex cannot be fully explained by physiological variables; hence, other factors such as skating technique warrant examination. Therefore, the purpose of this study was to evaluate the body movement kinematics of ice hockey skating starts between elite male and female ice hockey participants. Male (n = 9) and female (n = 10) elite ice hockey players performed five forward skating start accelerations. An 18-camera motion capture system placed on the arena ice surface captured full-body kinematics during the first seven skating start steps within 15 meters. Males’ maximum skating speeds were greater than females. Skating technique sex differences were noted: in particular, females presented ~10° lower hip abduction throughout skating stance as well as ~10° greater knee extension at initial ice stance contact, conspicuously followed by a brief cessation in knee extension at the moment of ice contact, not evident in male skaters. Further study is warranted to explain why these skating technique differences exist in relation to factors such as differences in training, equipment, performance level, and anthropometrics.  相似文献   
907.
Background: Within the context of sports coaching and coach education, formalised mentoring relationships are often depicted as a mentor–mentee dyad. Thus, mentoring within sports coaching is typically conceptualised as a one-dimensional relationship, where the mentor is seen as the powerful member of the dyad, with greater age and/or experience [Colley, H. (2003). Mentoring for Social Inclusion. London: Routledge].

Aim: The aim of this study was to explore the concept of a multiple mentor system in an attempt to advance our theoretical and empirical understanding of sports coach mentoring. In doing so, this paper builds upon the suggestion of Jones, Harris, and Miles [(2009). “Mentoring in Sports Coaching: A Review of the Literature.” Physical Education and Sport Pedagogy 14 (3): 267–284] who highlight the importance of generating empirical research to explore current mentoring approaches in sport, which in turn can inform meaningful formal coach education enhancement. The significance of this work therefore lies in opening up both a practical and a theoretical space for dialogue within sports coach education in order to challenge the traditional dyadic conceptualisation of mentoring and move towards an understanding of ‘mentoring in practice’.

Method: Drawing upon Kram’s [(1985). Mentoring at Work: Developmental Relationships in Organisational Life. Glenview, IL: Scott Foresman] foundational mentoring theory to underpin a multiple mentoring support system, 15 elite coach mentors across a range of sports were interviewed in an attempt to explore their mentoring experiences. Subsequently, an inductive thematic analysis endeavoured to further investigate the realities and practicalities of employing a multiple mentoring system in the context of elite coach development.

Results: The participants advocated support for the utilisation of a multiple mentor system to address some of the inherent problems and complexities within elite sports coaching mentoring. Specifically, the results suggested that mentees sourced different mentors for specific knowledge acquisition, skills and attributes. For example, within a multiple mentor approach, mentors recommended that mentees use a variety of mentors, including cross-sports and non-sport mentors.

Conclusion: Tentative recommendations for the future employment of a multiple mentoring framework were considered, with particular reference to cross-sports or non-sport mentoring experiences.  相似文献   

908.
Background: The advent of technology use in physical education is upon us. But the implications of using exergames as a substitute for traditional physical education instruction for some students raise questions. Although exergames have the potential to increase energy expenditure and motivation in some children, it is less clear whether they can provide skill acquisition benefits that are similar to those found in traditional physical education.

Purpose: In a previous experiment from our laboratory, we found that deliberate practice can significantly reduce the planning time required for lateral arm movements. The purpose of this study was to determine if exergames can produce a similar effect, by reducing the processing time required for children to initiate arm movements to the contralateral and ipsilateral space.

Participants and setting: Thirty children (boys?=?15, girls?=?15), between the ages of 7 and 12 years, participated in a pre- and post-test each taking 30?min and one 30?min treatment session in a university laboratory.

Research design: A repeated measures design was employed to test the effects of deliberate laterality practice on processing speed. Children were randomly assigned (n?=?10) to either a Nintendo Wii tennis contralateral movement experimental group, Nintendo Wii bowling ipsilateral movement experimental group, or handheld video-game control group. Each child participated in one 30?min treatment session.

Data collection: Upper extremity choice reaction time (RT) was measured through 27 goal-directed aiming movements for each arm separately, during the pre-test and post-test. The stimulus–response trials occurred in three randomly presented directions (ipsilateral, contralateral, and midline).

Data analysis: A 3 (treatment group)?×?2 (age group)?×?2 (test)?×?3 (direction) mixed design analysis of variance with repeated measures on the last two factors was used to test for significant differences, with an alpha level set at 0.05.

Findings: There were no significant treatment effects on RT across all groups indicating that a short bout of exergame training was unsuccessful in improving lateral movement processing.

Conclusions: Deliberate laterality practice using exergames did not improve the motor processing speed of lateral arm movements in the same manner of traditional physical education as indicated by our previous research. Explanations as to why exergames do not exhibit the same positive transfer for skill acquisition as traditional physical education instruction are discussed within this paper.  相似文献   
909.
Tennis featured in every Olympics from 1896 to 1924, after which disagreements between the International Olympic Committee (IOC) and the International Lawn Tennis Federation (ILTF) on matters pertaining to organisational control and the amateur eligibility of players led to tennis being removed from the Olympic Games as a full-medal event until the 1988 Seoul Olympics. This paper traces the steps of the sport’s reinstatement, from when efforts commenced in the 1950s, setting this development in the contexts of: broader political movements, shifting IOC leadership, burgeoning commercialisation of Olympic sport, the concomitant push for professionalisation and the declining influence of amateur ideals within both the Olympic movement and international tennis. Under the leadership of the amateur stalwart Avery Brundage, the IOC stymied attempts to facilitate tennis’s re-entry, challenging both the ILTF on failing to deal with widespread ‘sham-amateur’ practices and the avaricious promoters luring amateur players toward the professional ranks. Brundage and the IOC also strongly condemned the move to ‘open’ tennis and an acceptance of full-blown professionalism. Only a change in leadership, firstly with Lord Killanin and then the progressive reformer Juan Antonio Samaranch, did the IOC recognise the value of tennis within the Olympic movement, which by then had itself become increasingly money-oriented.  相似文献   
910.
The aim of this study is to determine changes in sedentary behaviour in response to extensive aerobic exercise training. Participants included adults who self-selected to run a marathon. Sedentary behaviour, total activity counts and physical activity (PA) intensity were assessed (Actigraph GT3X) for seven consecutive days during seven assessment periods (?3, ?2, and ?1 month prior to the marathon, within 2 weeks of the marathon, and +1, +2, and +3 months after the marathon). Models were fitted with multiple imputation data using the STATA mi module. Random intercept generalized least squares (GLS) regression models were used to determine change in sedentary behaviour with seven waves of repeated measures. Results: Twenty-three individuals (mean?±?Sx: 34.4?±?2.1y, 23.0?±?1.9% fat, 15 women, 8 men) completed the study. Marathon finishing times ranged from 185 to 344 minutes (253.2?±?9.6 minutes). Total counts in the vertical axis were 1,729,414 lower one month after the race, compared with two months prior to the race (peak training). Furthermore, counts per minute decreased by 252.7 counts·minute?1 during that same time period. Daily sedentary behaviour did not change over the seven assessment periods, after accounting for age, gender, per cent body fat, wear time, marathon finishing time, and previous marathon experience. This prospective study supports the notion that PA and sedentary behaviours are distinct, showing that sedentary behaviour was not impacted by high levels of aerobic training.  相似文献   
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