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131.
The impact absorption characteristics of cricket batting helmets 总被引:1,自引:0,他引:1
Stretch RA 《Journal of sports sciences》2000,18(12):959-964
To determine whether the helmets currently used by cricket batsmen offer sufficient protection against impacts of a cricket ball, the impact absorption characteristics of six helmets were measured using the drop test at an impact velocity equivalent to a cricket ball with a release speed of 160 km x h(-1) (44.4 m x s(-1)). An accelerometer transducer attached to a 5.0 kg striker was dropped from a height of 3.14 m onto the batting helmets to measure the impact characteristics at the three different impact sites: right temple, forehead and back of the helmet. These data were further expressed as a percentage above (-) or below (+) the recommended safety standard of 300 g. The results indicate that the force absorption characteristics of the helmets showed inter- and intra-helmet variations, with 14 of the 18 impact sites (66.7%) assessed meeting the recommended safety standards. Helmets 1, 2 and 4 succeeded in meeting the safety standards at all impact sites; helmets 5 and 6 both failed at the back and forehead, while helmet 3 failed at all impact sites. These differences were due to the structure and composition of the inner protective layer of the helmets. The helmets that succeeded in meeting the standards were made with a moulded polystyrene insert, a heat-formed ethylene vinyl acetate (EVA) insert, or EVA with a relatively high density that allows a minimal amount of movement of the helmet at ball impact. 相似文献
132.
Friedman SM Villamil K Suriano RA Egolf BP 《Public understanding of science (Bristol, England)》1996,5(1):1-20
During 1989, a major environmental and health risk issue, the spraying of Alar on apples, created a furor among the American people. After hearing charges from the Natural Resources Defense Council (NRDC) that eating Alar-laden apples significantly increased a child's risk of developing cancer, numbers of school districts dropped apples from their menus and parents poured apple juice down the drains. Apple sales plummeted. The NRDC's charges, which were disseminated by a well-planned and effective public relations campaign, brought counter-charges from the US environmental Protection Agency, which accused the NRDC of basing its study on poor data, among other things. The core of the dispute was in the risk figures and risk interpretations being used by each organization. 相似文献
133.
Ankeny RA 《Endeavour》2003,27(2):87-92
The history of science tends to be recounted as a story of progress from early goals and discoveries to a unified outcome, in some sense implicit from the beginning, and often due to technological advances. The sequencing of the human genome is no exception. As a crucial part of the Human Genome Project, the history of genomic sequencing is typically presented as a direct result of the discoveries of the structure of DNA and its coding function, together with practical factors such as the development of techniques which made large-scale sequencing possible. However, the history of sequencing is inevitably a more complicated story, not only about molecular biology, but also about the evolving culture of scientific practice at the end of the 20th century. 相似文献
134.
Jackson S Thompson RA Christiansen EH Colman RA Wyatt J Buckendahl CW Wilcox BL Peterson R 《Child abuse & neglect》1999,23(1):15-29
OBJECTIVE: According to sociological and ecological models of abuse, typically nonabusive parents could behave abusively towards their children under certain circumstances. The purpose of this study was to examine factors that place parents at risk of abusing their children by predicting parents' use of discipline practices and attitudes that may bias parents towards abusive behaviors, which we refer to as abuse-proneness. METHOD: A telephone interview was administered by the Gallup Organization to a nationally representative sample of 1,000 parents. Using a set of theoretically relevant risk factors, multiple regression was used to predict variations in parental attitudes (i.e., attitudes towards physical discipline and attitudes that devalue children) and parental discipline practices (i.e., physical discipline, nonphysical discipline, and verbal abuse). RESULTS: The findings confirmed the importance of examining elements of parental attitudes, history, personality characteristics, as well as religion and ideology in predicting abuse proneness. Child age also was an important predictor in all analyses except predicting parental attitudes that devalue children. The findings suggest also, however, that it may be unduly simplified to regard parents as somewhere on a continuum of nonpunitive to punitive disciplinarians. Social isolation was not a significant predictor in any of the analyses. CONCLUSIONS: Although many important theoretical predictors of abuse proneness were confirmed, many questions arise regarding the diversity of discipline practices that parents use, and the relevance of child's age and social isolation in predicting abuse proneness. Implications for practitioners and future research are discussed. 相似文献
135.
Toward a science for and of the people: promoting civil society through the application of developmental science 总被引:4,自引:0,他引:4
Applied developmental science (ADS) is scholarship that seeks to advance the integration of developmental research with actions-policies and programs-that promote positive development and/or enhance the life chances of vulnerable children and families. Through this integration ADS may become a major means to foster a science for and of the people. It may serve as an exemplar of the means through which scholarship, with community collaboration, may contribute directly to social justice. In so doing, ADS helps shift the model of amelioration, prevention, or optimization research from one demonstrating efficacy to one promoting outreach. When this contribution occurs in the context of university-community partnerships, ADS may serve also as a model of how higher education may engage policy makers, contribute to community capacity to sustain valued programs, and maintain and perpetuate civil society through knowledge-based, interinstitutional systems change. 相似文献
136.
This paper examined whether the greater average schooling and employment, and lower parenting competence, of young mothers who reside with adult relatives reflect preexisting differences versus potential causal mechanisms. The sample included 554 young mothers (ages 13 to 25; nearly two thirds African American) from the Infant Health and Development Program (IHDP) a random-assignment intervention study of premature, low birth weight babies followed 8 times from birth to age 3. Ordinary least squares, fixed-effects, and random-effects models indicated that young mothers of low birth weight babies sorted into extended households based on preexisting characteristics that were correlated with their lower parenting skills and knowledge. In contrast, coresidence predicted greater schooling or employment across models, with some variations for different subgroups. 相似文献
137.
Parental coping with children's negative emotions: relations with children's emotional and social responding 总被引:2,自引:0,他引:2
This study examined the relation between parents' reactions to children's negative emotions and social competence. Additionally, the role of parental emotional distress in children's emotional socialization was examined. The emotional reactions of 57 preschoolers (33 girls, 24 boys; M age = 59.2 months) were observed during their free-play interactions. Parents (mostly mothers) completed questionnaires about their reactions to children's negative emotions. An index of children's social competence was obtained from teachers. Results indicated that the relation between harsh parental coping strategies and children's emotional responding was moderated by parental distress. In addition, the relation of the interaction of parental coping and distress to children's social competence was mediated by children's level of emotional intensity. It was concluded that distressed parents who use harsh coping strategies in response to children's negative emotions have children who express emotion in relatively intense ways. In turn, these children find it relatively difficult to behave in a socially competent manner. 相似文献
138.