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91.
92.
ABSTRACT

The purpose of the study was to assess the validity and inter-bike reliability of 10 Wattbike cycle ergometers, and to assess the test–retest reliability of one Wattbike. Power outputs from 100 to 1000 W were applied using a motorised calibration rig (LODE) at cadences of 70, 90, 110 and 130 rev · min?1, which created nineteen different intensities for comparison. Significant relationships (P < 0.01, r2 = 0.99) were found between each of the Wattbikes and the LODE. Each Wattbike was found to be valid and reliable and had good inter-bike agreement. Within-bike mean differences ranged from 0.0 W to 8.1 W at 300 W and 3.3 W to 19.3 W at 600 W. When taking into account the manufacturers stated measurement error for the LODE (2%), the mean differences were less than 2%. Comparisons between Wattbikes at each of the nineteen intensities gave differences from 0.6 to 25.5 W at intensities of 152 W and 983 W, respectively. There was no significant difference (P > 0.05) between the measures of power recorded in the test–retest condition. The data suggest that the Wattbike is an accurate and reliable tool for training and performance assessments, with data between Wattbikes being able to be used interchangeably.  相似文献   
93.
Although most ACL injury prevention programmes encourage greater hip and knee flexion during landing, it remains unknown how this technique influences tibiofemoral joint forces. We examined whether a landing strategy utilising greater hip and knee flexion decreases tibiofemoral anterior shear and compression. Twelve healthy women (25.9 ± 3.5 years) performed a drop-jump task before and after a training session (10–15 min) that emphasised greater hip and knee flexion. Peak tibiofemoral anterior shear and compressive forces were calculated using an electromyography (EMG)-driven knee model that incorporated joint kinematics, EMG and participant-specific muscle volumes and patella tendon orientation measured using magnetic resonance imaging (MRI). Participants demonstrated a decrease in peak anterior tibial shear forces (11.1 ± 3.3 vs. 9.6 ± 2.7 N · kg?1; P = 0.008) and peak tibiofemoral compressive forces (68.4 ± 7.6 vs. 62.0 ± 5.5 N · kg?1; P = 0.015) post-training. The decreased peak anterior tibial shear was accompanied by a decrease in the quadriceps anterior shear force, while the decreased peak compressive force was accompanied by decreased ground reaction force and hamstring forces. Our data provide justification for injury prevention programmes that encourage greater hip and knee flexion during landing to reduce tibiofemoral joint loading.  相似文献   
94.
This study examined the psychometric properties of a questionnaire developed with the guidance of the socialization model of child behaviour to understand modifiable correlates of toddlers’ physical activity and sedentary behaviour. Findings are based on 118 parents (33.7 ± 4.9 years; 86% female) of toddlers (19.3 ± 2.7 months; 48% female) from Edmonton, Canada in The Parents’ Role in Establishing healthy Physical activity and Sedentary behaviour habits study (PREPS). The PREPS questionnaire encompassed 21 variables across the constructs of the socialization model of child behaviour. Of the nine variables assessed for internal consistency reliability, eight had good (α ≥ 0.70) reliability. Of the 15 continuous variables assessed for 1-week test–retest reliability, 10 had moderate (intra-class correlation = 0.50–0.74) and 5 had good (intra-class correlation ≥ 0.75) reliability. Of the six categorical variables assessed for 1-week test–retest reliability, two had fair (К = 0.21–0.40), one had moderate (К = 0.41–0.60), one had substantial (К = 0.61–0.80), and two had almost perfect (К = 0.81–1.00) reliability. Of the 12 sedentary behaviour variables assessed for convergent validity, 7 were significantly correlated with children’s screen time, of which three were small (r ≤ 0.29), two were medium (r = 0.30–0.49), and two were large (r ≥ 0.50) effect sizes.  相似文献   
95.
The aim of this study was to examine the association between alcohol consumption, alcohol sponsorship in sports and preferences of sponsored sportspeople regarding sponsorships/consumption. We investigate the impact of alcohol sponsorship on sportspeople in the Australian population using a national survey of sportspeople (N?=?2367), representing a range of club and professional sports. The results show an association between alcohol sponsorship of sport and increased alcohol consumption among sports participants (i.e. ‘sportspeople’). Additionally, a preference for sponsored alcohol brands was found by sponsored sportspeople. Our research adds to the growing evidence for policy review of alcohol sponsorship of sports and extends prior studies investigating impacts of alcohol sponsorship upon sports participants by generalizing to a large, national sample of sportspeople.  相似文献   
96.
TELEVISION AND BEHAVIOR: TEN YEARS OF SCIENTIFIC PROGRESS AND IMPLICATIONS FOR THE EIGHTIES (Washington: Government Printing Office, 1982—price not given, paper, two vols)

John P. Murray, TELEVISION & YOUTH: 25 YEARS OF RESEARCH & CONTROVERSY (Bowys Town Center for the Study of Youth Development, Research Use and Public Service Division, Boys Town, Neb. 68010—$10.00, paper)

TELEVISION'S IMPACT ON CHILDREN AND ADOLESCENTS: A SPECIAL INTEREST RESOURCE GUIDE IN EDUCATION (Oryx Press, 2214 N. Central at Encanto, Phoenix, Az. 85004—price not given, paper)  相似文献   
97.
98.
Abstract

An empirical examination of accredited American higher education institutions was conducted to obtain baseline data regarding distance education copyright, intellectual property, and antitrust concerns. Additionally, a multiple‐case study involving ten of the top thirty accredited distance education institutions in America was conducted. Policy approaches were examined for all institutions, and differences were discussed between public and private institutions as well as between the following Carnegie Classification institutions: Research I and II, Doctorate I and II, and Master's I and II. Data indicated that, out of the schools surveyed, 22% of the institutions in these Carnegie Classification categories published copyright and intellectual property policies on their institution's Web site. In the case study, it was found that 90% of the institutions centrally controlled their distance education program administration as well as the copyright and intellectual property policies related to it.  相似文献   
99.
Abstract

This paper summarises the results of an investigation of Solomon Islands secondary school students’ interpretations of three concepts: vision, animals and burning. Internal comparisons among the three areas and external comparisons with findings reported from other societies are made. While some support is given to the idea that children from different cultures may develop similar conceptions, this support is qualified and is shown to be dependent on the type of phenomenon investigated. The degree to which there is immediate personal experience of phenomena may be important, as may the presence or absence of culturally supported explanations. The commonly reported resistance of children's conceptions to school science teaching is also shown not to be universally true. The article ends with a plea for caution in the cross‐cultural extrapolation of research into children's conceptions.  相似文献   
100.
Abstract

This paper explores high school students’ perspectives of their learning in ascience unit which was taught using a Children's Science approach. Through the use of a questionnaire and interviews, this research examines how the students understood and responded to the changed demands on their learning as a result of the change in teaching style. Although the students appeared to be actively involved, interested and self‐directed in their learning, they were not convinced that this was an appropriate way forthem to approach their learning in future. It appears as though the time and effort associated with accepting more responsibility for learning is not matched by the value received from doing so in schools.  相似文献   
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