Interplay between motility and cell-substratum adhesion in amoeboid cells     

Xiaoying Zhu  Roland Bouffanais  Dick K. P. Yue 《Biomicrofluidics》2015,9(5)

The effective migration of amoeboid cells requires a fine regulation of cell-substratum adhesion. These entwined processes have been shown to be regulated by a host of biophysical and biochemical cues. Here, we reveal the pivotal role played by calcium-based mechanosensation in the active regulation of adhesion resulting in a high migratory adaptability. Using mechanotactically driven Dictyostelium discoideum amoebae, we uncover the existence of optimal mechanosensitive conditions—corresponding to specific levels of extracellular calcium—for persistent directional migration over physicochemically different substrates. When these optimal mechanosensitive conditions are met, noticeable enhancement in cell migration directionality and speed is achieved, yet with significant differences among the different substrates. In the same narrow range of calcium concentrations that yields optimal cellular mechanosensory activity, we uncovered an absolute minimum in cell-substratum adhesion activity, for all considered substrates, with differences in adhesion strength among them amplified. The blocking of the mechanosensitive ion channels with gadolinium—i.e., the inhibition of the primary mechanosensory apparatus—hampers the active reduction in substrate adhesion, thereby leading to the same undifferentiated and drastically reduced directed migratory response. The adaptive behavioral responses of Dictyostelium cells sensitive to substrates with varying physicochemical properties suggest the possibility of novel surface analyses based on the mechanobiological ability of mechanosensitive and guidable cells to probe substrates at the nanometer-to-micrometer level.  相似文献   

Suchting and the educational dangers of decontextualising science     

Jane Roland Martin 《Science & Education》1994,3(1):73-75

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Editorial     

Roland S. Persson 《High Ability Studies》2002,13(1):5-6

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Course Appraisal Using Semantic Differential Scales     

Roland Hoste 《Educational studies》1981,7(3):151-163

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MOTIVATIONAL AND INFLUENTIAL COMPONENTS OF MUSICAL PERFORMANCE: A QUALITATIVE ANALYSIS     

Roland S. Persson  George Pratt  Colin Robson 《High Ability Studies》1992,3(2):206-217

Fifteen pianists were asked to study the same piano piece for a period of time. They were then interviewed about motivation to pursue musical performance and factors which influence the generation of performance. Participants were encouraged to raise their own issues or refute the ones presented. The data were then subjected to a content analysis. It was assumed that emotion plays an important part in motivating a performer over a long period of time and also influences actual playing. Four main components common to the participants emerged as influencing performance generation. There also appeared to be four main components describing motives for pursuing music. The results suggest that emotion is intertwined with both performance generation and motivation for musical performance. Findings may have a bearing on the nurturing of musical talent, and imply that competitiveness could be detrimental rather than beneficial to an artistic endeavour.  相似文献   

The organisation and control of scientific research by the United Kingdom Government     

E. Roland Dobbs 《Higher Education》1972,1(3):345-355

The two recent reports, known as the Dainton and Rothschild Reports, on the organisation and control of the scientific research and development financed by the government of the United Kingdom are reviewed. The implications for research in the universities are discussed and some general principles for pure and applied research are suggested.

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Résumé L'article analyse le contenu des deux rapports récemment publiés et connus sous le titre de rapports Dainton et Rothschild qui sont consacrés à l'organisation et au contrôle de la recherche scientifique financée par le Gouvernement du Royaume-Uni. II soumet à la discussion les conséquences de ces études pour la recherche dans les universités et propose quelques principes généraux en matière de recherche pure et appliquée.

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Gender-related differences in exposure to and use of computers: Results of a survey of secondary school students     

Maria Bannert  Paul Roland Arbinger 《European Journal of Psychology of Education - EJPE》1996,11(3):269-282

A number of empirical studies on the use of computers reveals gender-related differences, with women and girls showing more negative feelings toward modern computer technology. Within the scope of an evaluation study of the pilot project “CULAS” (Computer Assisted Learning in Secondary Schools in Rhineland-Palatinate) the data of over 1000 students from grades 5 to 10 were analyzed with special focus on gender-related differences. The results of this study provide information on the following aspects: frequency and duration of computer use, computer experiences, computer interests, attitudes toward computers, emotional responses while working with computers, and locus of control. On a whole the results support the assumption of gender-related differences in exposure to and use of computers. However, these findings also indicate that this assumption may not hold true in a general sense, and that future studies must examine gender-related differences with more sophisticated methods.  相似文献   

Reviews     

Anthony Corones  Deborah Dowling  Andrew G. Bonnell  Jean Lachapelle  David Oldroyd  Emma Spary  Ben Oldroyd  Keith Campbell  Ragbir Bhathal  Phil Dowe  Antonina Harbus  Cathy Legg  Brian Martin  Yvonne Luxford  Nicolas Rasmussen  Paul Redding  Tim Sprod  Roland Sypel 《Metascience》1996,5(1):167-235

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高新技术中小企业的战略优势与劣势-战略发展分析     

Roland Helm　Reinhard Meckl 《科研管理》2004,25(Z1):120-124

工业国家的中小型高科技企业有很大的创新潜力,同时对所在地区的经济发展起到了积极的作用.由于公司规模大小不一,所以很难有时间从众多的案例中找到具体的管理技巧.本文主要对创新公司的战略等问题的具体内容和方法进行调查研究.  相似文献   

English and German academics’ perspectives on metrics in higher education: evaluating dimensions of fairness and organisational justice     

Bloch  Roland  Hartl  Jakob  O&#;Connell  Catherine  O&#;Siochru  Cathal 《Higher Education》2022,83(4):765-785

Higher Education - Many contemporary analyses criticise metrics-based evaluation in the higher education context as a neoliberal technology, notwithstanding the different national contexts and...  相似文献