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281.
Wrist-based accelerometers are now common in assessing physical activity (PA) and sedentary behaviour (SB) in population-based studies, but there is a scarcity of raw acceleration cutpoints in older adults. The study aimed to determine and evaluate wrist-based GENEActiv (GA) and hip-based ActiGraph GT3X+ (AG) raw acceleration cutpoints for SB and moderate-to-vigorous PA (MVPA) in older adults ≥60 years of age. A laboratory-based calibration analyses of 34 healthy older adults involved receiver operator characteristic (ROC) curves to determine raw acceleration cutpoints for SB and MVPA. ROC analysis revealed an area under the curve (AUC) of 0.88 for GA SB and MVPA, and 0.90 for AG SB and 0.94 for AG MVPA. Sensitivity optimised SB and specificity optimised MVPA GA cutpoints of 57 mg and 104 mg, and AG cutpoints of 15 mg and 69 mg were also generated, respectively. Cross-validation analysis revealed moderate agreement for GA and AG SB cutpoints, and fair to substantial agreement for GA and AG MVPA cutpoints, respectively. The resultant cutpoints can classify older adults as engaging in SB or not engaging in MVPA but the sensitivity optimised SB cutpoints should be interpreted with a degree of caution due to their modest cross-validation results.  相似文献   
282.
Numerous sport-based interventions exist which target marginalised or ‘at-risk’ young people with the intention of enabling some form of social change for programme participants. Very often, the objective of such interventions is the acquisition and development of qualities associated with ‘good citizenship’. However, critical scholars have noted how sport-based initiatives are frequently used as a form of social control, focusing on the development of personal responsibility. As such, these initiatives accentuate more passive forms of citizenship, as opposed to more active forms of citizenship towards which many educational policies and programmes are aimed. Nevertheless, there is a limited amount literature which explores the connection between sport-based interventions and citizenship development within marginalised or ‘at-risk’ youth populations. This paper presents findings from a small-scale, qualitative study of one such (football-based) intervention located in a number of inner-city boroughs of London, UK. Placing the accounts of programme participants and staff at the centre of the analysis, the paper: (i) uncovers the practicalities and nuances of football being utilised as a tool for social engagement, and (ii) explores broader notions of personal and behavioural development in relation to the acquisition of citizenship qualities. The paper concludes by suggesting that sporting activity may confer citizenship benefits for young people, but only when integrated into wider programmes of social support and community engagement.  相似文献   
283.
Research in psychology suggests that provision of an instruction by analogy can enhance acquisition and understanding of knowledge. Limited research has been conducted to test this proposition in motor learning by children. The purpose of the present study was to examine the feasibility of analogy instructions in motor skill acquisition by children. Thirty-two children were randomly assigned to one of the two instruction protocols: analogy and explicit instruction protocols for a two-week rope skipping training. Each participant completed a pretest (Lesson 1), three practice sessions (Lesson 2–4), a posttest and a secondary task test (Lesson 5). Children in the analogy protocol displayed better rope skip performance than those in the explicit instruction protocol (p?<?.001). Moreover, a cognitive secondary task test indicated that children in the analogy protocol performed more effectively, whereas children in the explicit protocol displayed decrements in performance. Analogy learning may aid children to acquire complex motor skills, and have potential benefits related to reduced cognitive processing requirements.  相似文献   
284.
In this paper we examine how incentives for collaboration shape collaborative behavior and researcher productivity in the context of EU-funded research networks. EU-funded research networks require researchers to collaborate as a condition for securing research funding. The presence of research funding, therefore, may influence collaborative behavior. Our approach involves isolating the effects of funding, collaboration and previous collaborations (prior to funding) on research output, and examining how the pattern of collaboration affects research productivity over time. Employing a panel of 294 researchers in 39 EU research networks over a 15-year period we find that while the impact of funding on productivity is generally positive the overall impact of collaboration within the funded networks is weak. When we delineate between pre-, during- and post-funding periods, however, we find some important differences. During the period of funding, collaboration did not lead to an increase in research production. In the post-funding period we find that although the number of collaborations decreases within the network, the impact of collaboration on productivity is positive and significant. Our findings suggest that collaborations formed to capitalize on funding opportunities, while not effective in enhancing researcher productivity in the short run, may be an important promoter of effective collaborations in the longer run.  相似文献   
285.
Julie:2008,多么精彩的一年!虽然2008年是鼠年,但我和Andy却把它称为“漏斗”年。在这一年里,4年一届的德国drupa展.3年一届的中国国际全印展以及每年一届的全美印艺展悉数登场,在这些展会上,许多厂商都根据自己的长期计划推出了自己的新产品和新服务。这些销售商都希望通过这些推广活动迅速获得成功。使用者也希望这些新技术能够帮助他们在印刷生产中提高生产能力和生产效率。  相似文献   
286.
2009年7月20~21日,柯达在其美国的代顿工厂迎来了DPS(数字印刷解决方案)分析日。本刊专栏作者Andy和Julie亲临现场,为我们发来精彩报道,深入解读柯达的未来发展。  相似文献   
287.
The purpose of this paper is to examine the stability of WTP estimates when discrete choice models are applied in cultural valuation studies. This valuation technique has recently emerged and is expected to be more widely applied in cultural economics. However, little is known about whether or not WTP estimates that are derived using different functional forms and structures in the same valuation study are stable enough to be within an acceptable range. This paper tries to examine the stability of estimated WTP values when uncertainty remains in the selection of best choice models. A more careful selection of choice models might be needed to improve the valuation reliability.  相似文献   
288.
The idea that characteristics acquired by an organism during its lifetime can be inherited by offspring and result in evolution is a substantial impediment to student understanding of evolution. In the current study, we performed a preliminary examination of how acquiring physical changes in a question prompt may differentially cue intuitive and scientific justifications of inheritance and evolution and how this varies based on how student learned the concept. Middle school students in a suburban northeastern district (N = 314) either learned about evolutionary change with a category construction task (with different levels of feedback support) or completed a worksheet. Three days later students responded to two free response scenarios (one where a physical change is acquired). Responses were coded based on student justifications for either science accuracy or intuitive nature. Specific reasons were coded by justification type with high inter-rater agreement (k > 0.93). Results showed that students were more likely to apply intuitive reasoning when a physical change was acquired (50%) than if the change was behavioral in nature (16%). Additionally, students who completed the category construction task provided significantly more scientifically accurate justifications about inheritance (M = 1.12) than control students (M = 0.47), and significantly less intuitive justifications (M = 0.67) than control (M = 1.13). Finally, category construction produced the most scientific reasoning when feedback was provided. Taken together, these results suggest that intuitive reasoning is differentially applied based on physical organismal changes, intuitive reasoning is less frequent when learning via category construction, and the category construction task is more effective for this population with the inclusion of feedback.  相似文献   
289.
The purpose of the study reported here was to analyse the ways in which unversity entrant science students carry out and communicate experimental activities and to identify a model to explain characteristic communication practices. The study was prompted by a need to inform the development of an introductory laboratory course. The students studied shared an educational background characterised by a lack of experience with laboratory work and scientific writing. Seven groups of three students were studied. The investigative strategies of these groups were observed. Laboratory reports were used to identify the ways in which students communicated these strategies. Data are presented that show a discrepancy between the strategies used and those reported. The results suggest that: (i) students' perceptions of the purpose of a laboratory task influence their decisions on what to report; (ii) understandings of laboratory procedures greatly influence their decision on what to report and on how much detail to include in a report and; (iii) knowledge of discourse rules contributes to effective reporting. It is concluded that students' communication of an investigation results from the differential operation of various perceptual filters that determine both the procedural and discourse elements of their reports. It is recommended that the communication of science should be taught explicitly and alongside the procedures and concepts of science. © 2000 John Wiley & Sons, Inc. J Res Sci Teach 37: 839–853, 2000  相似文献   
290.
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