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   

A fluid dynamic investigation of the Big Blade and Macon oar blade designs in rowing propulsion     

Caplan N  Gardner TN 《Journal of sports sciences》2007,25(6):643-650

The purpose of this investigation was to examine the fluid dynamic characteristics of the two most commonly used oar blades: the Big Blade and the Macon. Scaled models of each blade, as well as a flat Big Blade, were tested in a water flume using a quasi-static method similar to that used in swimming and kayaking research. Measurement of the normal and tangential blade forces enabled lift and drag forces generated by the oar blades to be calculated over the full range of sweep angles observed during a rowing stroke. Lift and drag force coefficients were then calculated and compared between blades. The results showed that the Big Blade and Macon oar blades exhibited very similar characteristics. Hydraulic blade efficiency was not therefore found to be the reason for claims that the Big Blade could elicit a 2% improvement in performance over the Macon. The Big Blade was also shown to have similar characteristics to the flat plate when the angle of attack was below 90 degrees , despite significant increases in the lift coefficient when the angle of attack increased above 90 degrees . This result suggests that the Big Blade design may not be completely optimized over the whole stroke.  相似文献   

Book reviews     

Finbarré Fitz Patrick  Nicholas Hawkes  James Cummins  Alison M. Pask  Carol Myers Scotton  R. N. Srivastava 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1978,24(3):423-434

  相似文献   

Change in mathematics education since the late 1950's-ideas and realisation     

Hans Freudenthal 《Educational Studies in Mathematics》1978,9(2):143-145

  相似文献   

How children respond to fiction     

Nicholas Tucker 《Children‘s Literature in Education》1972,3(3):48-56

  相似文献   

DOUBLE JEOPARDY PATTERNS FOR POLITICAL PARTIES     

Solgaard  Hans S.; Smith  David E.; Schmidt  Marcus 《Int. Journal of Public Opinion Research》1998,10(2):109-120

  相似文献   

Narrating Your Work: an approach to supporting knowledge sharing in virtual teams     

Anoush?MargaryanEmail author  Eleni?Boursinou  Dane?Lukic  Hans de?Zwart 《知识管理研究与实践》2015,13(4):391-400

We propose an approach to enhancing knowledge sharing and connectedness in distributed teams. Termed ‘Narrating Your Work’ (NYW), the approach involves members of distributed team using a microblogging tool to post regular updates about their current work, accomplishments, and issues. The NYW approach was evaluated within a geographically and temporally distributed team at Shell International for a period of one month, using a mixed-method research design. Methodology comprised of a quantitative survey, followed by semi-structured interviews and analysis of microblogging updates posted during the month in which the approach was being trialled. The evaluation results suggest that NYW was viewed as a valid and practical approach to enhancing knowledge sharing and connectedness. A range of barriers and enablers that could impact the future application and embedding of the approach are identified and recommendations for implementation are outlined.  相似文献   

Droplet formation and shrinking in aqueous two-phase systems using a membrane emulsification method     

Hans Breisig  Matthias Wessling 《Biomicrofluidics》2015,9(4)

Using a membrane emulsification method based on porous hollow-fiber membranes in combination with an aqueous two-phase system (ATPS), we are able to produce “water-in-water” droplets with narrow-dispersed size distributions. The equilibrium phases of the aqueous two-phase system polyethylene glycol-dipotassium hydrogen phosphate are used for this purpose. The droplet diameter of a given fluid system is determined by the flow rates of the continuous and disperse phase as well as the hollow fiber dimensions. When diluting the disperse phase and thus moving the ATPS system out of equilibrium, the droplet size can be further reduced in comparison to the equilibrium case. Generally, droplets formed with this method have diameters 20%–60% larger than the inner hollow fiber diameter. The new strategy of diluting the disperse phase allows the production of droplet diameter below the inner diameter of the membrane.  相似文献   

Struggling with Science and Status: Physiotherapy – Including Radiology and Cancer Treatment – and Physical Education at the State University in Ghent,Belgium, 1906–1936     

Pascal Delheye  Hans Vangrunderbeek 《国际体育史杂志》2015,32(6):815-831

The establishment of new academic specialties is an intriguing research topic from a social history of science perspective. In this article we focus on the ‘scientific migration’ within the Higher Institute of Physical Education (HIPE) and the Faculty of Medicine at the State University in Ghent, Belgium. The HIPE was ‘attached’ to the Faculty of Medicine in 1908, a world first that led to an interesting triangular relationship between physical education, physiotherapy, and medicine. The physiatrists (physicians-physiotherapists) who were appointed at the HIPE had to struggle with inferior status with respect to their colleagues within the Faculty of Medicine itself. Territorial power struggles arose on several levels. In 1936, after the first generation of physicians-physiotherapists had retired, physiotherapy was integrated fully into the Faculty of Medicine, and radiology and cancer treatment – which had been considered subsectors of physiotherapy – became autonomous specialties. Physical education, however, retained its inferior academic status.  相似文献   

Composing Film: Multimodality and Production in Elementary Classrooms     

Nicholas E. Husbye  Sarah Vander Zanden 《理论付诸实践》2015,54(2):109-116

Despite the proliferation of technology in contemporary lives, many elementary schools often do not account for other technologically-mediated ways of constructing meaning in their daily curriculum, including film. This article presents insights from 2 filmmaking projects with elementary-aged students illustrating how film allowed students to engage in collaborative, as well as multimodal, literacy practices. Greater instructional flexibility and possibility for nonlinear production are identified as positive benefits in approaching text production situated in filmmaking. Our investigation highlights how technology integration can bolster existing writing practices in the elementary classroom and can benefit students in ways that maximize flexible thinking and include diverse student perspectives.  相似文献