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991.
K L Sebastian 《Resonance》2007,12(5):48-59
Nano-sized molecular motors, which consume chemicals and do mechanical work are ubiquitous in nature. One of the most powerful
such motors is the viral packaging motor, which consumes ATP and packages the viral DNA into the procapsid (the protein shell)
of the virus. A pulling force applied to the loose end of the DNA can slow down the rate of packaging, thus showing that a
mechanical force can slow down a chemical reaction. In this article we describe this packaging process and what is known about
the mechanochemistry of the motor.
K L Sebastian is a Professor in the Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore.
His areas of interest is theoretical chemistry. 相似文献
992.
ABSTRACTThis article examines the role that business librarians can play in conveying the importance of thorough patent research in the start-up life cycle. It provides a summary of the components of the start-up life cycle and due diligence research as it pertains to entrepreneurs and venture capitalists. An overview of patent research resources and locations is provided, with particular focus on PatentsView, a web-based patent data visualization and analysis tool. 相似文献
993.
Managers predict the sales of new entertainment products prior to their release using comparables, such as similar books from the same author or movies with the same actors. In this study, the authors analyze whether diffusion models for media products provide helpful support in the management task of predicting prelaunch sales of the first distribution channel for three different product categories. They compare the performance of predictions based on (a) simple success factor regressions (OLS) and (b) diffusion models against real management predictions. Based on samples covering the German music, film, and the literary market, we show that model-based forecasts outperform the forecasts of management teams for the majority of the products. In contrast, management is superior in forecasting top sellers. This is due to unobserved factors arising from more management attention attached towards super stars. The authors do not find substantial prediction differences between simple success factor regressions and more complex diffusion models. Thus, managers interested in total sales estimates can easily rely on OLS based success factor predictions. Advertising and product differentiation factors with respect to quality (e.g., star power, critics, or country of origin) are across all 3 industries highly relevant for sales predictions, whereas others variables (e.g., price, distribution power, season, or competition) differ across industries. 相似文献
994.
Laura K. Clark 《Library & information science research》2017,39(2):107-115
A survey conducted at three Florida library systems examines caregivers' perceptions of emergent literacy programming and how these perceptions compare with the National Research Council's features for quality programs for children. The survey results reveal that caregivers' perceptions of emergent literacy programming align with the National Research Council's features. The data demonstrates that caregivers' perceptions are very positive toward emergent literacy programming in terms of learning and the environment. Caregivers' perceptions of the environment answers were mostly strongly agree. These results were more positive than their perceptions of learning, although they strongly agree that these programs prepare children for school, reading, and social interaction. The survey results will inform public libraries as to how to design, market, and deliver emergent literacy programming to caregivers with very young children. 相似文献
995.
996.
Prelinguistic babbling often seems remarkably speech-like, not because it has recognizable words but because it seems to have adult-like prosody. To quantify this impression, we compared disyllabic sequences from five infants and five adults in terms of the use of frequency, intensity, and duration to mark stress. Significantly larger values for the three acoustic variables were observed on stressed than on unstressed syllables independent of syllable position for both groups. Adults showed the correlates of utterance final syllables--lower f0, lower intensity, and longer duration; infants showed only decrease in intensity. Ratios for stressed to unstressed syllables and participation of the three variables in stress production in individual disyllables were highly similar in both groups. No bias toward the English lexical trochaic stress pattern was observed. We conclude that infants in English environments produce adult-like stress patterns before they produce lexical items, which specify stress. Acoustic and perceptual analyses are used to explore stress marking by prelinguistic infants in an English language environment. Results show that infants employ the three acoustic correlates of stress in individual syllables in a manner largely similar to that of adult speakers, although they do not show second-syllable declination effects or an English language trochaic stress bias. 相似文献
997.
Herbert W. Marsh Marjorie Seaton Ulrich Trautwein Oliver Lüdtke K. T. Hau Alison J. O’Mara Rhonda G. Craven 《Educational Psychology Review》2008,20(3):319-350
The big-fish–little-pond effect (BFLPE) predicts that equally able students have lower academic self-concepts (ASCs) when
attending schools where the average ability levels of classmates is high, and higher ASCs when attending schools where the
school-average ability is low. BFLPE findings are remarkably robust, generalizing over a wide variety of different individual
student and contextual level characteristics, settings, countries, long-term follow-ups, and research designs. Because of
the importance of ASC in predicting future achievement, coursework selection, and educational attainment, the results have
important implications for the way in which schools are organized (e.g., tracking, ability grouping, academically selective
schools, and gifted education programs). In response to Dai and Rinn (Educ. Psychol. Rev., 2008), we summarize the theoretical model underlying the BFLPE, minimal conditions for testing the BFLPE, support for its robust
generalizability, its relation to social comparison theory, and recent research extending previous implications, demonstrating
that the BFLPE stands up to scrutiny.
Quotations (associated page numbers) to the Dai and Rinn (2008) article are based on a prepublication version of the article available to the authors of this article that may have changed
during the final preparation for publication.
The authors would also like to express thanks to David Dai and Anne Rinn for their encouragement and assistance to us in preparation
of our article, whilst still acknowledging that they might not agree will all the views expressed here. 相似文献
998.
Until recently, no self‐report instruments have examined psychological skills use in both practice and competition. In light of the significant role of practice in sport performance outcomes, a need exists to measure these skills in both domains. This study was designed to investigate differences in performance strategies of US Olympians in both practice and competition. The Test of Performance Strategies was administered to 176 US participants in the 2000 Sydney Olympic Summer Games. Discriminant function analyses demonstrated significant differences between medalists and nonmedalists in both the competition and practice performance strategies. Furthermore, significant gender and age differences were identified for competition strategies only. The 16 subscales of the TOPS, with two exceptions, create an internally stable instrument with moderate predictive ability relative to quality of sport performance, gender, and age in this elite sample of athletes. 相似文献
999.
Erlane K. Ghani Jamaliah Said Noraini Mohd Nasir 《美中教育评论》2008,5(5):17-26
This study attempts to identify the factors perceived to be important in choosing an Institution of Higher Learning (IHL) for distance learning. One thousand five hundred questionnaires were distributed to the first year students in the social sciences distance learning programs and 980 valid responses were received of Malaysian public university. The results show that the top three factors influencing their preferred institution are qualification recognition IHL, future career advancement, and personal satisfaction. The results of this study provide insights to the IHL, employers and academics on the nature and relative importance of the factors perceived important for adult learners in the selection of their preferred IHL. 相似文献
1000.
Lena Löfgren Gustav Helldén 《International Journal of Science and Mathematics Education》2008,6(3):481-504
In order to develop successful teaching approaches to transformations of matter, we need to know more about how young students
develop an understanding of these processes. In this longitudinal study, we followed 25 students from 7 to 13 years of age
in their reasoning about transformations of matter. The questions addressed included how the students’ understanding of transformations
of matter changed and how we can make sense of individual learning pathways. In interviews performed once or twice every year
the students described and explained three situations: fading leaves left on the ground, a burning candle, and a glass of
water covered with a glass plate on which some mist had formed. When analysing the interviews, we found a common pathway of
how the students’ ideas changed over the years in each one of the situations. When analysing individual student’s interviews
with Ausubel’s assimilation theory we could discern subordinate, superordinate and combinatorial learning. How these findings
can contribute to an improvement of teaching about transformations of matter is discussed. 相似文献