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Thomas L. McKenzie James F. Sallis John P. Elder Charles C. Berry Patricia L. Hoy Philip R. Nader 《Research quarterly for exercise and sport》2013,84(3):195-202
Abstract We investigated physical activity and encouragement for activity in a bi-ethnic cohort during recess. Activity and associated interactions of 287 children were recorded at preschool and again 2.2 years later. Children expended nearly twice as much energy at preschool recess than at elementary recess. Activity levels declined as recess time elapsed. At preschool, European-American children engaged in more moderate to vigorous activity than Mexican-Americans. As participants moved to elementary school, teachers' prompts to be active decreased and prompts from peers increased. Boys and girls received similar amounts of activity prompts at preschool, but prompts to boys increased over time. The findings suggest that school environments could be altered to promote healthful physical activity among young children. 相似文献
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This paper suggests the need for a critical analysis of the nationalization of mourning and its educational implications, especially in conflict‐ridden areas. Our thoughts are grounded in a comparative study on mourning that has been conducted as part of our long‐standing ethnographic research in schools in Cyprus and Israel during the last 10 years. Through this study on mourning, we highlight two ideas. First, we want to show how a comparison of our studies in Cyprus and Israel highlights the difficulties for alternative interpretations to be translated into educational policies and teacher practices in the absence of changes in political structures. Second, we want to show that despite the forces that nationalize mourning, there are educational openings for alternative interpretations about mourning and the encouragement of reconciliation pedagogies. To this end, the education literature on teaching controversial issues and examples of pedagogies for reconciliation might be relevant to provide concrete ideas for education theory, policy and practice on issues of mourning. 相似文献
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Najmeh Daroogheh Nader Meskin Khashayar Khorasani 《Journal of The Franklin Institute》2018,355(8):3753-3794
Health monitoring of nonlinear systems is broadly concerned with the system health tracking and its prediction to future time horizons. Estimation and prediction schemes constitute as principle components of any health monitoring technique. Particle filter (PF) represents a powerful tool for performing state and parameter estimation as well as prediction of nonlinear dynamical systems. Estimation of the system parameters along with the states can yield an up-to-date and reliable model that can be used for long-term prediction problems through utilization of particle filters. This feature enables one to deal with uncertainty issues in the resulting prediction step as the time horizon is extended. Towards this end, this paper presents an improved method to achieve uncertainty management for long-term prediction of nonlinear systems by using particle filters. In our proposed approach, an observation forecasting scheme is developed to extend the system observation profiles (as time-series) to future time horizon. Particles are then propagated to future time instants according to a resampling algorithm instead of considering constant weights for the particles propagation in the prediction step. The uncertainty in the long-term prediction of the system states and parameters are managed by utilizing dynamic linear models for development of an observation forecasting scheme. This task is addressed through an outer adjustment loop for adaptively changing the sliding observation injection window based on the Mahalanobis distance criterion. Our proposed approach is then applied to predicting the health condition as well as the remaining useful life (RUL) of a gas turbine engine that is affected by degradations in the system health parameters. Extensive simulation and case studies are conducted to demonstrate and illustrate the capabilities and performance characteristics of our proposed and developed schemes. 相似文献
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Nader Wahbeh 《International Journal of Science Education》2013,35(3):425-466
This study (a) assessed the influence of an integrated nature of science (NOS) instructional intervention on inservice secondary science teachers' understandings, retention of those understandings, and their NOS instructional planning and practices; and (b) examined factors that mediated the translation of teachers' NOS understandings into practice. Nineteen teachers participated in an intensive, 6-week NOS course, which concluded with teachers developing plans to address NOS in their classrooms. Next, 6 participants were observed as they implemented their instructional plans. Data sources included pretest, posttest, and delayed-test NOS assessments, classroom observations, and several teacher-generated artifacts. The NOS course was effective in helping teachers develop informed NOS conceptions and retain those understandings 5 months after its conclusion. Teachers met with challenges and successes as they attempted to address NOS instructionally. The translation of NOS conceptions into practice was primarily mediated by the very nature of teachers' newly acquired NOS understandings, which were situated within the science contents, contexts, and experiences in which they were developed (i.e. the NOS course); thus, limiting participants' abilities to transfer their understandings into novel contexts and contents. The results helped build a model of the sources of science teachers' pedagogical content knowledge for teaching about NOS in content-rich contexts. 相似文献
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J F Sallis T L Patterson J A Morris P R Nader M J Buono 《Research quarterly for exercise and sport》1989,60(4):318-324
Whereas modest familial aggregation of VO2max has been documented after controlling for variables such as physical activity habits, the effect of adjustment for moderating variables has not been directly tested. This issue was addressed in 95 Anglo and 111 Mexican-American families who underwent submaximal cycle ergometer testing. Zero-order correlations of predicted VO2max between pairs of family members were generally weak for both Anglo families (r = 0.04 to 0.35) and Mexican-American families (r = 0.03 to 0.50). Five of 12 correlations were significant. Similar results were found for combined ethnic groups. Adjustment for age, physical activity, and body mass index by partial correlation had few significant effects on aggregation of predicted VO2max. Adjustment for body mass index produced significant decreases in the correlation for Anglo spouses and mother-older child and sibling pairs in the combined group. Although influential moderating variables were not identified, body mass index was found to be a significant, though inconsistent, mediator of aggregation of VO2max. Genetic factors were not strongly supported because of generally weak aggregation in the two ethnic groups. 相似文献