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911.
912.
Multicultural classrooms and cultural communities of teachers 总被引:1,自引:0,他引:1
This paper addresses issues of teacher adoption of culturally responsive pedagogy through reporting data from a 2-year ethnographic study of a teacher education program located in the U.S.A. The research findings reveal that preservice teachers experience and ultimately adopt a meritocratic and hegemonic system of schooling in which academic performance is viewed in terms of individual abilities and based on mainstream norms. The study suggests that, for substantive changes to take place in multicultural classrooms, teacher educators need to engage in the kind of critical examination which will lead to curricular reform intended to foster alternatives to hegemonic experiences and beliefs. 相似文献
913.
Damir Zubac Tomislav Antelj Dragana Olujic Vladimir Ivancev Shawnda A. Morrison 《Journal of sports sciences》2017,35(8):719-726
This study investigated (i) the prevalence of hypohydration and (ii) association between urinary indices of hydration status and confounding factors (e.g., urine protein content, water intake) in elite youth boxers during their weight-stable phase before competition. Sixteen national champion boxers (all male, 17 ± 1 y) were measured on 3 occasions (baseline, day 3, day 10), 30-day prior to competition. Body mass, total body water, urine specific gravity (USG), osmolality (UOSM) and total protein content (TPC) were evaluated to determine hydration status and fluid balance. Overall macronutrient and water intake were assessed using dietary records. Both UOSM and USG increased from day 3 to day 10 by 16% and 0.4% (P < 0.001), despite athletes being in their weight-stability period, and regardless of ad libitum fluid intake. Hypohydration was universally prevalent among all athletes on both test days with USG: 1.027 ± 0.003 g · mL?1 and UOSM: 1035 ± 108 mOsmol · kg?1. An inverse association between mean UOSM values and mean water intake was observed (R = ?0.52, P = 0.04), while TPC was not associated with any urinary dehydration markers (USG, P = 0.51; UOSM, P = 0.61). The present outcomes find that the most prevalent urinary dehydration markers used to classify hydration status in competition exhibit large variability, even during weight-stable periods. 相似文献
914.
Hillary A. Plummer 《Journal of sports sciences》2017,35(2):182-188
Team handball is a popular sport worldwide that requires numerous throws to be made throughout the course of a game. Because of the upper extremity demands of repetitive throwing, it is possible that fatigue can alter the mechanics of a shot. The purpose of this study was to determine the influence of localised fatigue on jump shot kinematics and kinetics. Eleven male team handball players (23.1 ± 3.1 years; 185.1 ± 8.3 cm; 89.7 ± 12.2 kg) volunteered. An electromagnetic tracking system was used to examine the jump shot prior to and following localised fatigue. The fatiguing protocol consisted of throwing a 2.2 kg medicine ball into a rebounder until volitional fatigue. No significant kinematic or kinetic differences were observed following fatigue. Shoulder external rotation was ?74.8 ± 14.9° prior to and ?79.0 ± 14.7° following fatigue at MER. Scapula, external rotation at ball release (BR) prior to fatigue was ?2.2 ± 7.0° and ?3.2 ± 11.1° following fatigue. Scapular internal rotation, at maximum shoulder internal rotation (MIR), changed from 18.4 ± 11.2° to 20.4 ± 11.8°. Ball velocity decreased from19.8 m · s–1 to 18.8 m · s–1 (P = 0.12). Accuracy percentage in the pre-fatigue trials was 60.8 ± 14.1% and 52.8 ± 12.7% following fatigue (P = 0.20). While no significant changes were observed, it is possible that other fatiguing protocols that more closely represent the aerobic and throwing demands of the sport may have a greater effect on the kinematics and kinetics of the jump shot. 相似文献
915.
Joshua T. Weinhandl Bobbie S. Irmischer Zachary A. Sievert Kevin C. Fontenot 《Journal of sports sciences》2017,35(2):166-174
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
916.
James A. H. Smith Alexander D. McKerrow Tertius A. Kohn 《Journal of sports sciences》2017,35(16):1592-1597
Exercise testing on motorised treadmills provides valuable information about running performance and metabolism; however, the impact of treadmill type on these tests has not been investigated. This study compared the energy demand of running on two laboratory treadmills: an HP Cosmos (C) and a Quinton (Q) model, with the latter having a 4.5 times stiffer running platform. Twelve experienced runners ran identical bouts on these treadmills at a range of four submaximal velocities (reported data is for the velocity that approximated 75–81% VO2max). The stiffer treadmill elicited higher oxygen consumption (C: 46.7 ± 3.8; Q: 50.1 ± 4.3 ml·kg?1 · min?1), energy expenditure (C: 16.0 ± 2.5; Q: 17.7 ± 2.9 kcal · min?1), carbohydrate oxidation (C: 9.6 ± 3.1; Q: 13.0 ± 3.9 kcal · min?1), heart rate (C: 155 ± 16; Q: 163 ± 16 beats · min?1) and rating of perceived exertion (C: 13.8 ± 1.2; Q: 14.7 ± 1.2), but lower fat oxidation (C: 6.4 ± 2.3; Q: 4.6 ± 2.5 kcal · min?1) (all analysis of variance treadmill comparisons P < 0.01). This study confirms that caution is required when comparing performance and metabolic results between different treadmills and suggests that treadmills will vary in their comparability to over-ground running depending on the running platform stiffness. 相似文献
917.
Joshua H. Guy Andrew M. Edwards Catherine M. Miller Glen B. Deakin David B. Pyne 《Journal of sports sciences》2017,35(16):1622-1628
Prospective application of serum cytokines, lipopolysaccharide (LPS), and heat shock proteins (eHSPs) requires reliable measurement of these biomarkers that can signify exercise-induced heat stress in hot conditions. To accomplish this, both short-term (7 day) reliability (at rest, n = 12) and the acute responsiveness of each biomarker to exercise in the heat (pre and post 60-min cycling, 34.5°C and 70% RH, n = 20) were evaluated. Serum was analysed for the concentration of C-reactive protein (CRP), interleukin-6 (IL-6), heat shock protein 72 (eHSP72), immunoglobulin M (IgM) and LPS. Test–retest reliability was determined as the coefficient of variation (CV). Biomarkers with the least short-term within-participant variation were IL-6 (19%, ±20%; CV, ±95% confidence limits (CL)) and LPS (23%, ±13%). Greater variability was observed for IgM, eHSP72 and CRP (CV range 28–38%). IL-6 exhibited the largest increase in response to acute exercise (95%, ±11%, P = < 0.001) and although CRP had a modest CV (12%, ±7%), it increased substantially post-exercise (P = 0.02, ES; 0.78). In contrast, eHSP72 and LPS exhibited trivial changes post-exercise. It appears variation of common inflammatory markers after exercise in the heat is not always discernible from short-term (weekly) variation. 相似文献
918.
Jason Moran Gavin R. H. Sandercock Rodrigo Ramírez-Campillo César Meylan Jay Collison Dave A. Parry 《Journal of sports sciences》2017,35(11):1041-1051
This meta-analysis investigated the maturation-related pattern of adaptations to resistance training in boy athletes. We included studies examining the effects of 4–16-week resistance training programmes in healthy boy athletes aged 10–18 years. Pooled estimates of effect size for change in strength across all studies (n = 19) were calculated using the inverse–variance random effects model for meta-analyses. Estimates were also calculated for groups based on likely biological maturity status (“before”, “during” and “after” peak height velocity). Using the standardised mean difference, resistance training increased strength across all groups (effect size = 0.98, [CI: 0.70–1.27]). Strength gains were larger during (1.11 [0.67–1.54]) and after (1.01 [0.56–1.46]) peak height velocity than before (0.5 [?0.06–1.07]). Adaptations to resistance training are greater in adolescent boys during or after peak height velocity. These findings should help coaches to optimise the timing of training programmes that are designed to improve strength in boy athletes. 相似文献
919.
Aïmen Khacharem 《Journal of sports sciences》2017,35(12):1204-1210
Comprehension of a narrated diagram entail complex cognitive processing as learner is challenged to extract the orally evoked information. The present experiment examined the effects of 2 different forms of attention guidance – bottom-up and top-down – on comprehension performance, cognitive load investment, and motivation to learn, using a 2 × 2 mixed design with factors “Expertise” (Expert vs. Novice) and “Condition” (no-signal, circle, segment). The results revealed an expertise reversal effect indicating that the incorporation of visual signals in diagram is effective for novice learners but partially reverses and becomes ineffective for more experienced learners (even though they invested less mental effort and reported higher level of motivation in the segmented condition). The findings suggested that the effectiveness of instructional guidance depends heavily on levels of prior knowledge. 相似文献
920.
Katherine A. Boyer Julia Freedman Silvernail Joseph Hamill 《Journal of sports sciences》2017,35(22):2225-2231
The purpose of this study was to examine the impact of age on running mechanics separately for male and female runners and to quantify sex differences in running mechanics and coordination variability for older runners. Kinematics and kinetics were captured for 20 younger (10 male) and 20 older (10 male) adults running overground at 3.5 m · s?1. A modified vector coding technique was used to calculate segment coordination variability. Lower extremity joint angles, moments and segment coordination variability were compared between age and sex groups. Significant sex–age interaction effects were found for heel-strike hip flexion and ankle in/eversion angles and peak ankle dorsiflexion angle. In older adults, mid-stance knee flexion angle, ankle inversion and abduction moments and hip abduction and external rotation moments differed by sex. Older compared with younger females had reduced coordination variability in the thigh–shank transverse plane couple but greater coordination variability for the shank rotation–foot eversion couple in early stance. These results suggest there may be a non-equivalent aging process in the movement mechanics for males and females. The age and sex differences in running mechanics and coordination variability highlight the need for sex-based analyses for future studies examining injury risk with age. 相似文献