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Purpose: The purpose of this study was to investigate whether loads carried in a backpack, with a load mass ranging from 0 to 20?kg, causes respiratory muscle fatigue. Methods: Eight males performed four randomised load carriage (LC) trials comprising 60?min walking at 6.5?km?h?1 wearing a backpack of either 0 (LC0), 10 (LC10), 15 (LC15) or 20?kg (LC20). Inspiratory (PImax) and expiratory (PEmax) mouth pressures were assessed prior to and immediately following each trial. Pulmonary gas exchange, heart rate (HR), blood lactate and glucose concentration and perceptual responses were recorded during the first and final 60?s of each trial. Results: Group mean PImax and PEmax were unchanged following 60-min load carriage in all conditions (p?>?.05). There was an increase over time in pulmonary gas exchange, HR and perceptions of effort relative to baseline measures during each trial (p?.05) with changes not different between trials (p?>?.05). Conclusions: These findings indicate that sub-maximal walking with no load or carrying 10, 15 or 20?kg in a backpack for up to 60?min does not cause respiratory muscle fatigue despite causing an increase in physiological, metabolic and perceptual parameters. 相似文献
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This paper addresses a dynamic portfolio investment problem. It discusses how we can dynamically choose candidate assets, achieve the possible maximum revenue and reduce the risk to the minimum level. The paper generalizes Markowitz's portfolio selection theory and Sharpe's rule for investment decision. An analytical solution is presented to show how an institutional or individual investor can combine Markowitz's portfolio selection theory, generalized Sharpe's rule and Value-at-Risk(VaR) to find candidate assets and optimal level of position sizes for investment (dis-investment). The result shows that the generalized Markowitz's portfolio selection theory and generalized Sharpe's rule improve decision making for investment. 相似文献
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Mark Featherstone 《Educational Philosophy and Theory》2018,50(14):1514-1515
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Demand for private supplementary tutoring: conceptual considerations, and socio-economic patterns in Hong Kong 总被引:3,自引:0,他引:3
Despite the fact that in some parts of the world private supplementary tutoring is a huge industry with far-reaching economic, social and educational implications, the topic has been neglected by educational researchers. This paper focuses on the nature and determinants of demand for private supplementary tutoring. It first draws on literature from a wide range of countries to identify some conceptual considerations, and then presents data on socio-economic patterns of demand for tutoring in Hong Kong. It highlights the complexity of the topic, and calls for further detailed research in multiple settings. 相似文献
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Elizabeth K. Briody Angela Goldenstein Edward J. Berger 《European Journal of Engineering Education》2019,44(5):666-687
ABSTRACTStudies have found that Faculty–Student Interaction (FSI) has many positive benefits for students including academic support, professional development, mentoring, and career planning. Research-intensive universities exhibit the lowest levels of faculty–student interaction within higher education. This article utilises qualitative methods to explore faculty, student, and staff perceptions of faculty–student interactions, particularly those that take place out of the classroom, at a research-intensive public U.S. university. We identify social distance between faculty and students based on unequal status within a rigid, hierarchically-organised culture as a key barrier to FSI. We then discuss methods that some of the faculty in our study used to mitigate their social distance with students in an effort to increase FSI. 相似文献
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Radford University was recently configured with a campus-wide wireless local area network. Using these new capabilities, a
classroom-based Honors section of Concepts of Biology was conducted solely using electronic technologies (paper was never
transferred from professor to student). To accomplish this, students used common software and freeware. Commercial versions
of similar software are designed solely for academic use, however, here the students were trained to use software and technologies
that will be available to them once leaving the institution. Overall, students in this course responded favorably to the use
of technology and reported that it aided in their learning process. 相似文献