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101.
Despite being invasive within surrounding brain tissues and the central nervous system, little is known about the mechanical properties of brain tumor cells in comparison with benign cells. Here, we present the first measurements of the peak pressure drop due to the passage of benign and cancerous brain cells through confined microchannels in a “microfluidic cell squeezer” device, as well as the elongation, speed, and entry time of the cells in confined channels. We find that cancerous and benign brain cells cannot be differentiated based on speeds or elongation. We have found that the entry time into a narrow constriction is a more sensitive indicator of the differences between malignant and healthy glial cells than pressure drops. Importantly, we also find that brain tumor cells take a longer time to squeeze through a constriction and migrate more slowly than benign cells in two dimensional wound healing assays. Based on these observations, we arrive at the surprising conclusion that the prevailing notion of extraneural cancer cells being more mechanically compliant than benign cells may not apply to brain cancer cells. 相似文献
102.
Moslem Bahmani Abbas Bahram Jed A Diekfuss Saeed Arsham 《Journal of sports sciences》2013,31(20):2318-2330
ABSTRACTThe aims of this study were to (1) to explore attentional strategies in expert judo players and (2) investigate how attentional focus affects performance effectiveness and perceptions of workload in expert judo players during real competitions. Fourteen expert male judo players participated in the study. A simulated recall method was used following participants’ competition to explore contents of attention qualitatively. The data analysis process for the qualitative portion of the study was an iterative process between inductive and deductive analyses. Quantitative analyses of performance outcomes and workload were then associated with the qualitative findings. Qualitative results revealed that the focus of attention was dynamic and complex, with technical aspects of the movements as the highest identified focus. Quantitative analyses revealed that reporting a lower quantity of attentional cues and higher percentage of focus on opponent resulted in higher performance effectiveness and less perceptions of workload. This study indicates that cognitive control and automaticity may work in a synergistic manner for successful skill execution in expert performance. 相似文献
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Z S Masangkay K A McCluskey C W McIntyre J Sims-Knight B E Vaughn J H Flavell 《Child development》1974,45(2):357-366
105.
Christine Z. Howe 《Studies in Educational Evaluation》1978,4(1):19-23
It was in the late sixties when the formal evaluation of teachers and their courses by students in their classes first became routinized at the University of Illinois at Urbana. Students and teachers alike were told that the purpose of the evaluations was to improve college teaching. The instruments were advocated on the basis of being vehicles for student expression in the higher education process and as part of the whole move towards accountability. In practice, however, the evaluations were used by department heads or chairpersons as part of the basis for decisions about salary, retention, promotion, and tenure. Thus, the need for a new approach to course evaluation, concentrating on improving instruction was recognized. This paper is an account of a course evaluation using the responsive approach. 相似文献
106.
Susan L. Swars Stephanie Z. Smith Marvin E. Smith Jody Carothers Kayla Myers 《Journal of Mathematics Teacher Education》2018,21(2):123-145
Many in the field of mathematics education call for elementary schools to have elementary mathematics specialists (EMSs) who provide needed mathematical expertise and support for children and teachers. EMSs serve as a reasonable, immediate alternative to the challenges generated by elementary teachers needing improved mathematical knowledge for teaching in the classroom. However, limited inquiry has explored how to best prepare EMSs and how program features and learning activities influence their development. This mixed-method study identifies some of the interrelated benefits from a K-5 Mathematics Endorsement Program designed to prepare EMSs through examining changes in mathematical beliefs, specialized content knowledge (SCK), and classroom teaching practices during the program. Data (n = 32) were collected over the 2-semester program via belief surveys, a content knowledge assessment, observations of teaching practices, and individual interviews from elementary teachers participating in the program. The findings show some changes in beliefs can be made relatively quickly, other shifts in beliefs take more time and continued support, and changes in SCK and adoption of various aspects of standard-based pedagogy require considerably greater opportunities to learn. The described program features and learning experiences provided a context for these changes and offer considerations for EMS preparation programs. 相似文献
107.
Infant Affective Reactions to the Resumption of Maternal Interaction after the Still-Face 总被引:4,自引:0,他引:4
To investigate infants' reactions to the Face-to-Face Still-Face Paradigm and in particular the reunion episode, 50 6-month-olds' affective, behavioral, and physiologic reactions were recorded and analyzed. Infants reacted to the still-face with negative affect, a drop in vagal tone, and an increase in heart rate. By contrast, they reacted to the reunion episode with a mixed pattern of positive and negative affect. There was a carryover of negative affect from the still-face, an increase in fussiness and crying, and a rebound of positive affect. During this episode, the infants' heart rate and vagal tone returned to initial levels. The data indicate that infant affective displays are specifically related to different interactive events, but that their physiologic reactions do not show the same level of specificity. The findings also highlight the complexity of the affective and reparatory processes that take place in mother-infant interactions. 相似文献
108.
肉桂是我国名贵中药材和芳香原料,它的应用历史相当悠久,但对肉桂粉实病的系统研究,在国内外尚为首次。通过调查研究,查明该病的发生规律和病原菌花生油盘孢菌(Elaeodemafloricola)的特性。 相似文献
109.
110.
Vernon Fryburger William A. Robinson Herbert S. Gardner Jr. Jack Z. Sissors E.R. Petray Arthur Bellaire 《Communication Booknotes Quarterly》2013,44(7):98-100
How it Was in Advertising: 1776-1976 ($6.95, paper, 110 pp.) Vernon Fryburger, The New World of Advertising ($6.95, paper, 129 pp.) William A. Robinson, 100 Best Sales Promotions (annual, $19.95, about 140 pp. each) Herbert S. Gardner Jr. The Advertising Agency Business ($19.95, 211 pp.) Jack Z. Sissors and E.R. Petray Advertising Media Planning ($12.95, 341 pp.) Arthur Bellaire Controlling Your TV Commercial Costs ($19.95, 166 pp.) Julie M. Moss '77 Ayer Public Relations and Publicity Style Book (Ayer Press, 210 West Washington Square, Philadelphia, Pa. 19106—$9.95) 相似文献