排序方式： 共有14条查询结果，搜索用时 218 毫秒
1.
Comparison of two Actigraph models for assessing free-living physical activity in Indian adolescents
Corder K Brage S Ramachandran A Snehalatha C Wareham N Ekelund U 《Journal of sports sciences》2007,25(14):1607-1611
This aim of this study was to compare the new Actigraph (GT1M) with the widely used Model 7164. Seven days of free-living physical activity were measured simultaneously using both the Model 7164 and GT1M in 30 Indian adolescents (mean age 15.8 years, s = 0.6). The GT1M was on average 9% lower per epoch than model 7164, thus a correction factor of 0.91 is suggested for comparison between the two monitors. The differences between monitors increased in magnitude with intensity of activity (P < 0.001) but remained randomly distributed (r = 0.01, P = 0.96). No significant difference was observed between monitors for time spent in moderate (P = 0.31) and vigorous (P = 0.34) physical activity when using the same epoch length. The Model 7164 classified less time as sedentary (P < 0.001) and more time as light-intensity activity (P < 0.001) than the GT1M. In conclusion, data from the GT1M can be compared with historical data using average counts per minute with a correction factor, and the two models might be comparable for assessing time spent in moderate to vigorous physical activity in children when using the same epoch length. 相似文献
2.
Mike Boyes Tom Potter Soren Andkjaer Martin Lindner 《Journal of Adventure Education & Outdoor Learning》2013,13(4):343-357
ABSTRACTThis article explores the influential role of planning on recognition-primed decision-making. Considerable prior thinking occurs and there is a need to trace and account for the cognitive processes that precede and guide decisions in dynamic outdoor environments. Seven expert leaders from four countries were interviewed about memorable decisions made on outdoor journeys with an educational focus on land, sea and ice. Four stages of planning were identified: (1) long-term preparation; (2) formal leadership meetings; (3) day-by-day planning on route and (4) thinking immediately prior to the event. The stages sequentially capture the planning progression, illuminating the cognitive processes at each stage to culminate in option selection. In each decision situation, planned goals and actions were implemented through the creation and re-creation of micro-plans. As windows of opportunity presented themselves, the flexible execution of plans was a key feature. Planning provided the solid bedrock upon which decisions were made. 相似文献
3.
Mona Bekkhus Alicia McVarnock Robert J. Coplan Vidar Ulset Brage Kraft 《Child development》2023,94(4):1078-1086
Shyness is a temperamental trait that shares considerable conceptual overlap with aspects of internalizing problems, creating difficulties in operationalizing and assessing these two constructs and their association. This study addresses these issues by employing network analyses. Participants were, white, N = 555 children (Mage = 52.45 months, SD = 15.96, 55% girls) followed longitudinally over 4 years (2016–2010) in Norway. Teachers rated child shyness and assessed children's internalizing symptoms. Results suggest that two behavioral shyness traits were the most central aspects of shyness. The centrality of these aspects was robust across age. The most influential symptom connecting internalizing symptoms with shyness was “unhappy.” Shyness became more differentiated with development, and associations between anxiety-related symptoms and shyness increased as children entered formal schooling. 相似文献
4.
Kemi OJ Rognmo O Amundsen BH Stordahl S Richardson RS Helgerud J Hoff J 《Journal of sports sciences》2011,29(2):161-170
Maximal strength training with a focus on maximal mobilization of force in the concentric phase improves endurance performance that employs a large muscle mass. However, this has not been studied during work with a small muscle mass, which does not challenge convective oxygen supply. We therefore randomized 23 adult females with no arm-training history to either one-arm maximal strength training or a control group. The training group performed five sets of five repetitions of dynamic arm curls against a near-maximal load, 3 days a week for 8 weeks. This training increased maximal strength by 75% and improved rate of force development during both strength and endurance exercise, suggesting that each arm curl became more efficient. This coincided with a 17-18% reduction in oxygen cost at standardized submaximal workloads (work economy), and a 21% higher peak oxygen uptake and 30% higher peak load during maximal arm endurance exercise. Blood flow assessed by Doppler ultrasound in the axillary artery supplying the working biceps brachii and brachialis muscles could not explain the training-induced adaptations. These data suggest that maximal strength training improved work economy and endurance performance in the skeletal muscle, and that these effects are independent of convective oxygen supply. 相似文献
5.
Benchmarks for Science Literacy (AAAS 1993) lists for four gradelevels the steps by which students might achieve science literacy before leaving high school. These steps and the conceptual connections among them are now being mapped to suggest where anyone idea or skill comes from, what it is connected to, and where it leads. A set of 49 such strand maps appears in Atlas of Science Literacy (AAAS 2001). This paperdescribes strand maps in general and examinesthree draft maps titled Evidence and Reasoning, Scientific Investigations, and Scientific Theories, which together represent one section of Benchmarks Chapter 1, on scientific inquiry. The maps do not prescribe any particular curriculum, but can aid in planning a variety of curricula, analyzing instructional materials, assessing student understanding, and can be used in professional development for teachers. 相似文献
6.
This article examines approaches to creating museum Web sites that offer quality experiences to online users. In six case studies, museum Web developers in the U.S. and Canada describe how they have made the most of available human and financial resources. The development history of each site offers insights into the origins of a design and its subsequent versions, and describes the influence of institutional missions, philosophies, success indicators—and financial and human resources, the most crucial factors. The study found considerable variety in the backgrounds, expertise, titles and training of people developing Web sites within institutions. Web teams developed “exchange” experiences through online discussion, and by creating links among users, or between museum staff and users. In three case studies, Web sites encouraged visitors to cycle between online and on‐site museum visits. Web developers describe using quantitative and qualitative online audience research strategies. WebTrendsTM software has enabled Web teams to report complex log analyses. Creating online experiences in partnership with users is the intention of Web developers. 相似文献
7.
A fundamental criterion for reusing and continuously improving knowledge in product development is ensuring that the knowledge is explicit and visual.This paper is based on the situation of an engineer-to-order（ETO） manufacturing company,where historically grown product variety and related knowledge are diffuse（tacit）.Consequently,several resources are used in（re）developing derivatives of previous products rather than innovating new ones.To establish a more competitive configure-to-order（CTO） product strategy,product knowledge needs to be revealed,systemized,and structured,and thus made explicit.Hence,product-specific knowledge and product variants have been analyzed and subsequently mapped at architectural,functional,and physical levels in one unified map and tested in the form of a proof-of-concept（POC）demonstrator with the introduced SME company.The result is a product portfolio map that forms a base for defining a systemized,transparent,unified product variant overview,which can be used as a basis for implementing a cross-variant product architecture and supporting knowledge-based approaches. 相似文献
8.
9.
Nicole Blum Joanne Nazir Soren Breiting Kim Chuan Goh Erminia Pedretti 《Environmental Education Research》2013,19(2):206-217
This paper addresses one of the key challenges for work on education, sustainable development and climate change: the overall conceptualisation of central ideas such as Environmental Education (EE), Education for Sustainable Development (ESD) and Climate Change Education (CCE). What do these concepts mean in diverse contexts and amongst diverse actors? The paper draws on evidence from Denmark, Singapore, Canada and the UK to highlight both the similarities and differences found within national discussions around these essentially contested concepts and their relationships to policy and practice. It further argues that such debates about how EE, ESD and CCE are conceptualised remain highly relevant, not just to academic work itself, but also to wider international discussions regarding both the current and potential relationships between conceptual understanding, policy and practice. 相似文献
10.
Erin R. Hager Margarita S. Treuth Candice Gormely LaShawna Epps Soren Snitker Maureen M. Black 《Research quarterly for exercise and sport》2013,84(4):397-405
Purpose: Ankle accelerometry allows for 24-hr data collection and improves data volume/integrity versus hip accelerometry. Using Actical ankle accelerometry, the purpose of this study was to (a) develop sensitive/specific thresholds, (b) examine validity/reliability, (c) compare new thresholds with those of the manufacturer, and (d) examine feasibility in a community sample (low-income, urban adolescent girls). Method: Two studies were conducted with 6th- through 7th-grade girls (aged 10–14 years old): First was a laboratory study (n = 24), in which 2 Actical accelerometers were placed on the ankle and worn while measuring energy expenditure (Cosmed K4b2, metabolic equivalents [METs]) during 10 prescribed activities. Analyses included device equivalence reliability (intraclass correlation coefficient [ICC], activity counts of 2 Acticals), criterion-related validity (correlation, activity counts and METs), and calculations of sensitivity, specificity, kappa, and receiver-operating characteristic curves for thresholds. The second was a free-living study (n = 459), in which an Actical was worn for more than 7 days on the ankle (full 24-hr days retained). Analyses included feasibility (frequencies, missing data) and paired t tests (new thresholds vs. those of the manufacturer). Results: In the laboratory study, the Actical demonstrated reliability (ICC = .92) and validity (r = .81). Thresholds demonstrated sensitivity (91%), specificity (84%), kappa = .73 (p = .043), area under curve range = .81–.97. In the free-living study, 99.6% of participants wore the accelerometer; 84.1% had complete/valid data (mean = 5.7 days). Primary reasons for missing/invalid data included: improper programming/documentation (5.2%), failure to return device (5.0%), and wear-time ≤ 2 days (2.8%). The moderate-to-vigorous physical activity threshold (> 3,200 counts/minute) yielded 37.2 min/day, 2 to 4.5 times lower than that of the manufacturer's software (effect size = 0.74–4.05). Conclusions: Validity, reliability, and feasibility evidences support Actical ankle accelerometry to assess physical activity in community studies of adolescent girls. When comparing manufacturers' software versus new thresholds, a major difference was observed. 相似文献