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81.
This study attempts to answer two questions. First, can a single cultural event impact the stock prices of a wide range of companies and sectors? Second, was the positive stock market response in the information technology (IT) sector as well as performing arts sector significant? To answer these questions, we examine whether a hit pop single, “Gangnam Style” by Park Jae-Sang in 2012, affected related sectors of the Korean stock market and whether market reactions went beyond the stock price of the singer’s agency to affect those of other firms. We use an event study approach. The results show two notable empirical findings. First, although the findings indicating abnormal returns and cumulative abnormal returns appear mixed, the overall results imply that the unprecedented worldwide hit single by the South Korean singer positively affected the Recreation & Culture and Digital Content sectors. In other words, the market interpreted the event as good news, with shareholders expecting positive effects on the related sectors. Second, a positive stock market response was observed in the IT sector as well.  相似文献   
82.
Controversial results reported in past research pertaining to the effectiveness of sport-based physical activity interventions on weight loss. The purpose of this study was to assess the impact of sport-based physical activity intervention on body weight in children and adolescents using a meta-analysis. Academic Search Complete, Education Source, ERIC, Medline, ProQuest, PsycINFO and SportDiscus databases were searched from January 2000 to April 2015. Eighteen studies met following inclusion criteria: sport-based intervention studies; subjects aged 6–18 years; reported body weight; published in peer-reviewed journals written in English. The mean intervention duration was 17.72 weeks. The overall effect size (ES) was 0.52 (Cohen’s d (ES) = 0.52, 95% CI = 0.08, 0.95, P = 0.021), using a random effects model. Moderator analyses results showed that the Q statistic for the sport type (individual sport or team sport, Qbetween (Qb) = 14.52, df = 1, P = 0.001) and diet control (Qbetween (Qb) = 8.85, df = 1, P = 0.001), explained the heterogeneity of ESs. Our study showed that there was a moderate overall effect of sport-based physical activity intervention on body weight reduction. The team sport type (ES = 1.05, 95% CI = 0.44, 1.66) and diet control group (ES = 0.84, 95% CI = 0.26, 1.41) appeared to be more effective in reducing body weight.  相似文献   
83.
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   
84.
Limb dominance theory suggests that females tend to be more one-leg dominant and exhibit greater kinematic and kinetic leg asymmetries than their male counterparts, contributing to the increased risk of anterior cruciate ligament injury among female athletes. Thus, the purpose of this study was to examine the influences of sex and limb dominance on lower extremity joint mechanics during unilateral land-and-cut manoeuvres. Twenty-one women and 21 men completed land-and-cut manoeuvres on their dominant limb as well as their nondominant limb. Three-dimensional kinematics and kinetics were calculated bilaterally for the entire stance phase of the manoeuvre. Women performed land-and-cut manoeuvres with altered hip motions and loads as well as greater knee abduction at touchdown compared to men. Dominant limb land-and-cut manoeuvres where characterised by decreased hip flexion at touchdown as well as decreased hip flexion and adduction range of motion compared to nondominant land-and-cuts regardless of sex. The observed sex differences are consistent with previous research regarding mechanisms underlying the sex disparity in anterior cruciate ligament injury rates. However, observed differences regarding limb dominances appear somewhat arbitrary and did not suggest that the dominant or nondominant limb would be at increased risk of anterior cruciate ligament injury.  相似文献   
85.
The 100 ms ruling for false start disqualification at athletic competitions governed by the International Association of Athletics Federations has been in force since the early 1990s. Throughout this period, there have been marked changes to the rules that govern the disqualification of athletes from sprint events incorporating starts from blocks. This study analysed all available World and European Championship response-time (RT) data from 1999 to 2014 to examine effects of rule changes on competition RT at major championships. The exponentially modified Gaussian distribution was used to model RT and make comparisons relative to athletes’ sex, ruling periods and competition rounds. Revised RT thresholds of 115 ms and 119 ms were identified for men and women, respectively, indicating that the current 100 ms rule could result in some false starts not being detected in competitive athletics. The study proposes that when using existing International Association of Athletics Federations approved systems, the false start detection threshold should be increased and that men and women athletes should have different thresholds because of substantial evidence of a sex-based difference in RT in elite-standard athletes.  相似文献   
86.
The purpose of the study was to investigate the effect of different kicking modality, i.e., erratic-dynamic target (EDT) versus static target (ST) on the performance of the roundhouse kick in two groups of taekwondo athletes of different skill level. Three-dimensional analysis and surface electromyography (SEMG) analysis were performed on 12 (Group A: six sub-elite, Group B: six elite) athletes to investigate muscle co-activation pattern under two conditions, i.e., EDT versus ST. In the results, the muscle recruitment ratio of the agonistic muscles was higher for Group A, whereas Group B had higher recruitment ratio for antagonist muscles. Overall, the co-activation index (CI) of hip joints appeared higher in the extensors for Group A, whereas higher CI was observed in flexor muscles for Group B with comparatively higher CI during EDT condition than ST condition. Higher value of CI was observed in flexor muscles of the knee joints among Group A during EDT conditions, in contrast, higher CI in the extensor muscles was observed among Group B during ST conditions. In conclusion, the study confirmed that erratic-dynamic movements of target could change the movement coordination pattern to maintain the joint stability of participants.  相似文献   
87.
Purpose: A relationship exists between attitudes toward physical education and future physical activity. The purpose of this study was to examine changes in attitude toward physical education as students progressed from upper elementary school (Grade 4) through middle school (Grade 8). Method: Three cohorts of students (Cohort 1, Grades 4–6, = 96; Cohort 2, Grades 5–7, = 71; and Cohort 3, Grades 6–8, = 73) were each followed for 3 years to examine changes in attitudes toward physical education. Results: After an initial increase from Grade 4 to Grade 5, a significant decrease was observed from Grades 5 to 8 in students’ positive attitudes toward physical education, with a faster rate of change for girls than boys. Conclusion: This longitudinal study provides further insights regarding the attitudes of students as they progress from Grade 4 to Grade 8 and expands on previous findings identifying decreasing positive attitudes toward physical education as students age, particularly for girls. The results provide evidence to support targeted interventions.  相似文献   
88.
Purpose: Scholarship is essential for the growth and development of the physical education field. Over time, scholarship expectations have changed, forcing faculty members to alter time spent for research, teaching, and service. Social-cognitive career theory (SCCT) presents a model for understanding performance and persistence in an occupational environment. The interconnected aspects of SCCT have different emphasis related to self-efficacy, outcome expectations, or personal goals pursuit. This study explored physical education teacher education (PETE) faculty members’ continuing engagement in scholarly activity through SCCT. Method: Data collection included interviews with 9 senior PETE faculty members who met the criteria for “productive scholars over time.” Curriculum vitae were collected to verify productivity. Results: Data analysis revealed guidepost themes that included collaborating, finding balance, defining a research process, and maintaining a strong work ethic. Roadblocks encountered included other obligations and lack of support for research. Conclusions: Participants demonstrated strong self-efficacy; held high, positive expectations for success; and set very specific, clear, and deliberate goals. Participant behavior was moderated by their personal attributes (capacity to build relationships, set goals, and maintain interest and passion) and was tempered by the environments in which they worked. Fostering similar behaviors has the potential to guide future and current PETE faculty members in creating supportive and encouraging atmospheres for sustained productivity. The lack of literature relating to this topic warrants the need for more research exploring the influential factors and benefits gained from sustained scholarly productivity over time for PETE faculty members.  相似文献   
89.
Primary objective: Teacher evaluation is being revamped by policy-makers. The marginalized status of physical education has protected this subject area from reform for many decades, but in our current era of system-wide, data-based decision-making, physical education is no longer immune. Standardized and local testing, together with structured observation measures, are swiftly being mandated in the USA as required elements of teacher evaluation systems in an effort to improve school programs and student achievement. The purpose of this investigation was to document how this reform was initiated and the experiences of teachers, students and administrators, from three high school physical education programs, during initiation of this reform. Documenting how physical education programs respond to such reforms develops our understanding of top-down reform efforts and helps to identify conditions under which such reforms have the intended effect on physical education teachers and student learning in physical education.

Theoretical framework: Fullan’s three phases of school change has been used to analyze and guide school change efforts in several subject areas including physical education. The phases are initiation, implementation and institutionalization. This study is situated primarily within the first phase of school change, the initiation phase.

Methods and procedures: This study took place over a 21-month period in 3 suburban school districts in a northeast metropolitan area of the USA. Interviews with district physical education administrators, high school physical education teachers and students were conducted. Field notes of physical education classes, informal interviews and related artifacts including pre- and post-physical education assessments were collected. To ensure trustworthiness, several steps were taken including member checks, triangulation and peer review. The data were analyzed to find common themes and patterns using the constant comparative method.

Results: Several themes emerged: (1) changes in curriculum and assessment; (2) effect on administrators; (3) stakeholder apathy and (4) department collaboration.

Conclusion: Changes, although minor, did take place in the wake of this top-down teacher reform; however, additional research needs to be completed to determine whether or not these changes are meaningful or long lasting.  相似文献   

90.
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