Sequence-dependent rotation axis changes and interaction torque use in overarm throwing     

Clint Hansen  Nasser Rezzoug  Philippe Gorce  Gentiane Venture  Brice Isableu 《Journal of sports sciences》2016,34(9):878-885

We examined the role of rotation axes during an overarm throwing task. Participants performed such task and were asked to throw a ball at maximal velocity at a target. The purpose of this study was to examine whether the minimum inertia axis would be exploited during the throwing phases, a time when internal–external rotations of the shoulder are particularly important. A motion capture system was used to evaluate the performance and to compute the potential axes of rotation (minimum inertia axis, shoulder–centre of mass axis and the shoulder–elbow axis). More specifically, we investigated whether a velocity-dependent change in rotational axes can be observed in the different throwing phases and whether the control obeys the principle of minimum inertia resistance. Our results showed that the limbs’ rotational axis mainly coincides with the minimum inertia axis during the cocking phase and with the shoulder–elbow axis during the acceleration phase. Besides these rotation axes changes, the use of interaction torque is also sequence-dependent. The sequence-dependent rotation axes changes associated with the use of interaction torque during the acceleration phase could be a key factor in the production of hand velocity at ball release.  相似文献   

Competence-Based Vocational Education and Training (VET): the Cases of England and France in a European Perspective     

Michaela Brockmann  Linda Clarke  Philippe Méhaut  Christopher Winch 《Vocations and Learning》2008,1(3):227-244

This paper examines the notion of ‘competence’ in the VET systems of France and England. While both countries have developed ‘competence-based’ approaches, underlying the similar terminology are distinct meanings, rooted in the countries’ institutional structures and labour processes. A key distinction is identified between a knowledge-based model in France and a skills-based model in England. Competence in the French sense is multi-dimensional and relies on the integration of practical and theoretical knowledge, as well as personal and social qualities within a broadly defined occupational field. By contrast, in England, competence refers to the performance of fragmented and narrowly defined tasks, with minimal underpinning knowledge. Thus, whereas ‘competence’ in the English VET system usually denotes functional employability for what may be relatively low-skilled employment, in France, it encapsulates the multi-dimensional development of the individual as a citizen as well as an employee.

Michaela BrockmannEmail:

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Toward the Ideal Study Guide: an exploration of the functions and components of study guides     

Philippe Duchastel 《British journal of educational technology : journal of the Council for Educational Technology》1983,14(3):216-231

The study guide, as an important resource for student learning, is here conceptualized in an ideal general form. The process starts with an examination of its instructional context, then explores the learning functions it is meant to support. This in turn leads to a sketch of the practical components which can be employed in the design of a study guide, with a discussion of various practical decisions to be made along the way. The ideal study guide which is developed here is only meant as a prototype, a template of sorts for particular instructional design efforts in study guide development.  相似文献   

The role of stress processing abilities in the development of bilingual reading     

Vincent Goetry  Lesly Wade‐Woolley  Rgine Kolinsky  Philippe Mousty 《Journal of Research in Reading》2006,29(3):349-362

French and Dutch differ regarding the manifestations and lexical functions of the stress pattern of words. The present study examined group differences in stress processing abilities between French‐native and Dutch‐native listeners, thus extending previous cross‐linguistic comparisons involving Spanish‐native and French‐native adults. The results show that Dutch‐native first‐graders significantly outperformed French monolinguals, and that French‐native listeners schooled in Dutch produced intermediary performances, suggesting that stress‐processing abilities are a learnable set of skills. The present study also examined the contribution of stress processing abilities to reading development in Dutch, a stress‐based language, compared to that in French, a syllable‐based language. Although the expected correlation between stress processing abilities and reading was not observed in the Dutch monolinguals, such correlation was observed in the French‐native bilinguals schooled in Dutch and not in the Dutch‐native bilinguals schooled in French. This suggests that stress processing abilities influence reading development in a second, stress‐based, language. Moreover, the monolinguals and bilinguals schooled in Dutch showed significant associations between lexical development and stress processing abilities. Ways in which prosody might be involved in lexical and reading development are explored and discussed.  相似文献   

Asian achievement,brain size,and evolution: Comments on A. H. Yee     

J. Philippe Rushton 《Educational Psychology Review》1995,7(4):373-380

Asian achievement is now recognized to be global in manifestation. Yet most explanations of group differences remain narrowly focused on one country (the U.S.A.), on one character (test scores), and from one viewpoint (environmentalism). I offer an evolutionary perspective. Genetic distance estimates indicate an African origin for humans about 200,000 years ago, a dispersal event out of Africa about 110,000 years ago, and a Mongoloid-Caucasoid split about 41,000 years ago. This racial succession is matched by cranial capacities, IQ test scores, speeds of decision time, and numerous other life-history variables including rate of physical maturation, family functioning, testosterone level, law-abidingess, and frequency of dizygotic twinning. Evolutionary selection pressures are more cognitively demanding in the cold arctic where mongoloids evolved than in the hot savanna where Africans evolved. Genetic theories are needed to explain the proportionate group differences.  相似文献   

Biomedical innovation at the laboratory, clinical and commercial interface: A new method for mapping research projects, publications and patents in the field of microarrays     

Andrei Mogoutov  Alberto Cambrosio  Peter Keating  Philippe Mustar   《Journal of Informetrics》2008,2(4):341-353

Using the example of microarrays, one of the constitutive technologies of post-genomic biomedicine, this paper introduces a method for analyzing publications, patents and research grants as proxies for “triple-helix interfaces” between university, industry and government activities. Our method creates bridges that allow one to move seamlessly between publication, patent and research project databases that use different fields and formats, and contain different information. These links do not require pre-defined categories in order to search for correspondences between sub-topics or research areas in the three databases. Finally, our results are not restricted to quantitative information but, rather, allow one to carry out qualitative investigations of the content of research activities. Our approach draws on a combination of text-mining and network analysis/mapping software packages.  相似文献   

Blood,politics, and social science. Richard Titmuss and the Institute of Economic Affairs, 1957-1973     

Fontaine P 《Isis; an international review devoted to the history of science and its cultural influences》2002,93(3):401-434

Long before his last book, The Gift Relationship: From Human Blood to Social Policy, was published in early 1971, Richard M. Titmuss (1907-1973), a professor of social administration at the London School of Economics, had been a major figure in the debates over the welfare state. The Gift Relationship was the culmination of an eventful relationship with the Institute of Economic Affairs, a think tank that advocated the extension of rational pricing to social services. By arguing that the British system of blood procurement and distribution, based on free giving within the National Health Service, was more efficient than the partly commercialized American system, Titmuss intended to signal the dangers of the increasing commercialization of society. What made for the impact of his book, however, was not merely its argument that transfusion-transmitted infections were much more common with paid than with voluntary donors, but also its reflections on what it is that holds a society together. And here Titmuss argued that a "socialist" social policy, by encouraging the sense of community, played a central role. The eclecticism of Titmuss's work, together with its strong ethical and political flavor, makes it a rich and original account of the "social" at a time when heated debated over social policy, both in Britain and in the United States, raised the question of the division of labor among the social sciences.  相似文献   

阿尔卑斯山高山-亚高山过渡区高山黄花茅的群体遗传结构和分化研究     

赵桂仿  Francois Felber  Philippe Kuepfer 《中国科学院研究生院学报》2001,39(1):20-30

应用等位酶分析，在瑞士阿尔卑斯山的阿尔拜特(Arpette)和拜阿尔普(Belalp)，沿三个不同的海拔梯度，研究了高山黄花茅3个自然居群的遗传变异和分化。研究结果表明，平均的多态性位点比例为64．9％，每个位点平均等位基因数为2．37，平均期望杂合性为0．252。亚居群间平均的遗传距离为0．011，发现79％的遗传变异存在于居群内。基于等位酶分析，边缘亚居群与中心亚居群似乎有类似的遗传变异性。相对比较高的遗传分化、低的亚居群间基因流和小的邻居大小值暗示，近交和随后的遗传漂变可能是导致阿尔拜特黄花茅居群遗传变异性较低的主要原因。  相似文献   

Climate and litter C/N ratio constrain soil organic carbon accumulation     

Guoyi Zhou  Shan Xu  Philippe Ciais  Stefano Manzoni  Jingyun Fang  Guirui Yu  Xuli Tang  Ping Zhou  Wantong Wang  Junhua Yan  Gengxu Wang  Keping Ma  Shenggong Li  Sheng Du  Shijie Han  Youxin Ma  Deqiang Zhang  Juxiu Liu  Shizhong Liu  Guowei Chu  Qianmei Zhang  Yuelin Li  Wenjuan Huang  Hai Ren  Xiankai Lu  Xiuzhi Chen 《国家科学评论(英文版)》2019,6(4):746

Soil organic carbon (SOC) plays critical roles in stabilizing atmospheric CO₂ concentration, but the mechanistic controls on the amount and distribution of SOC on global scales are not well understood. In turn, this has hampered the ability to model global C budgets and to find measures to mitigate climate change. Here, based on the data from a large field survey campaign with 2600 plots across China''s forest ecosystems and a global collection of published data from forested land, we find that a low litter carbon-to-nitrogen ratio (C/N) and high wetness index (P/PET, precipitation-to-potential-evapotranspiration ratio) are the two factors that promote SOC accumulation, with only minor contributions of litter quantity and soil texture. The field survey data demonstrated that high plant diversity decreased litter C/N and thus indirectly promoted SOC accumulation by increasing the litter quality. We conclude that any changes in plant-community composition, plant-species richness and environmental factors that can reduce the litter C/N ratio, or climatic changes that increase wetness index, may promote SOC accumulation. The study provides a guideline for modeling the carbon cycle of various ecosystem scales and formulates the principle for land-based actions for mitigating the rising atmospheric CO₂ concentration.  相似文献   

A miniaturized continuous dielectrophoretic cell sorter and its applications   总被引：1，自引：0，他引：1  

Ana Valero  Thomas Braschler  Nicolas Demierre    Philippe Renaud 《Biomicrofluidics》2010,4(2)

There is great interest in highly sensitive separation methods capable of quickly isolating a particular cell type within a single manipulation step prior to their analysis. We present a cell sorting device based on the opposition of dielectrophoretic forces that discriminates between cell types according to their dielectric properties, such as the membrane permittivity and the cytoplasm conductivity. The forces are generated by an array of electrodes located in both sidewalls of a main flow channel. Cells with different dielectric responses perceive different force magnitudes and are, therefore, continuously focused to different equilibrium positions in the flow channel, thus avoiding the need of a specific cell labeling as discriminating factor. We relate the cells’ dielectric response to their output position in the downstream channel. Using this microfluidic platform that integrates a method of continuous-flow cell separation based on multiple frequency dielectrophoresis, we succeeded in sorting viable from nonviable yeast with nearly 100% purity. The method also allowed to increase the infection rate of a cell culture up to 50% of parasitemia percentage, which facilitates the study of the parasite cycle. Finally, we prove the versatility of our device by synchronizing a yeast cell culture at a particular phase of the cell cycle avoiding the use of metabolic agents interfering with the cells’ physiology.  相似文献