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81.
This study examined how grouping arrangements affect students achievement, social interaction, and motivation. Students of high, average and low ability were randomly assigned to homogeneous or heterogeneous ability groups. All groups attended the same plant biology course. The main results indicate that low-ability students achieve more and are more motivated to learn in heterogeneous groups. Average-ability students perform better in homogeneous groups whereas high-ability students show equally strong learning outcomes in homogeneous and heterogeneous groups. Results on social interaction indicate that heterogeneous groups produce higher proportions of individual elaborations, whereas homogeneous groups use relatively more collaborative elaborations. In the discussion, these differences in social interaction are used to explain the differential effects of grouping arrangements on achievement scores. Practical implications are discussed and topics for further research are advanced.  相似文献   
82.

Objective  

The roles of gonadal hormones and nitric oxide (NO) on the analgesic effects of morphine, tolerance to morphine, and their interactions have been widely investigated. In the present study, the effect of l-arginine (an NO precursor) on morphine tolerance in sham and ovariectomized (OVX) female mice was investigated.  相似文献   
83.
Median noise barriers, like parallel noise barriers, can be employed to reduce the impact of traffic on roadside communities via the direct propagation path. The performance of different shapes of median barriers was compared using reactive and passive surfaces and a 2D boundary element method (BEM). In the case of reactive surfaces, quadratic residue diffusers (QRDs) and primitive root diffusers (PRDs) were used on the top and stem surfaces of median barriers. To introduce passive barriers, two different absorbent materials including fibrous material and a grass surface with flow resistivity of 20 000 and 2500 kg/(s·m2), respectively, were similarly applied. The effect of thin absorptive barriers was similar at lower frequencies and better at mid and high frequencies to that of their equivalent rigid barriers. More improvement was achieved by covering the top surface of thick barriers with grass rather than with fibrous material. The performance of QRD and PRD barriers where the diffuser was located on the top surface was more frequency dependent than that of barriers coated with fibrous material. A comparison of the average A-weighted insertion loss in the thick barriers showed that the greatest improvement (2.59 dB (A)) was achieved using a barrier of 30-cm thickness covered with grass.  相似文献   
84.
Student populations in higher education in Australia and elsewhere in the developed world have experienced significant diversity over the past two decades. The existing literature has provided limited clarity about the effects of this diversity on the dimensions underpinning students' study philosophy domain. Based on a large data set from a leading Australian university, this paper analyses students' study philosophy, beliefs and attitudes towards teaching and learning. Factor analysis explored themes (or dimensions) within the survey. Multivariate analysis of variance used these dimensions as dependent variables with age, sex, ethnicity, study discipline, study level, academic performance and sex/ethnicity interaction as grouping variables to identify significant sources of variations. Deep learning, expediency and responsibility reflected the students' study philosophy domain. Deep learning and responsibility varied with ethnicity and academic performance. Expediency differed according to ethnicity, study discipline and academic performance. Students in business-related disciplines displayed greater expediency than peers elsewhere, treating education like any other commodity. The contribution of this study lies in its rigorous analysis of the impact of the diversity of the student population on the study philosophy domain, compared to the existing literature.  相似文献   
85.
This research studies on the e-learning services acceptance in higher education institutions in Brunei Darussalam. This research has seven hypotheses, relating to independent, intermediary, and dependent variables. The independent variables include lecturer’s characteristics, design of learning contents, teaching materials, and playfulness; while the intermediary variables are perceived benefits and perceived ease of use. On the other hand, the dependent variable in this research is the intention to use e-learning. Multiple regression analysis were conducted to test the hypotheses proposed. Data analysis from this research has confirmed that the lecturer’s characteristics, teaching materials, perceived ease of use and the intention to use e-learning corresponds to the perceived benefits. Meanwhile, the design of learning content and the intention to use e-learning are positively related to the perceived ease of use and lastly, the variable playfulness is positively related to the intention to use e-learning.  相似文献   
86.
INTRODUCTION Rice (Oryza sativa L.) is one of the most im-portant crops in Pakistan. It is the third largest crop interms of area and production after wheat and cotton.Although rice in Pakistan is consuming large acreage,Pakistan is still far behind other rice producingcountries. The average yield is very low (2 t/ha) ascompared to Egypt (8.4 t/ha) and USA (6.6 t/ha).There are many reasons for this low yield. The mostimportant are high temperature (40?50 °C), low hu-midity at …  相似文献   
87.
Abstract

The purpose of this paper is to examine librarians' perceptions of knowledge management, including its concept, potential applications, benefits and major challenges of its applications in Indian academic libraries. A structured questionnaire, containing both open and close-ended questions, was sent by postal mail to 30 librarians of academic libraries in India of which 15 questionnaires were returned. Respondents were asked to define knowledge management and answer questions on its potential applications, benefits and major challenges of implementation in academic libraries. Respondents were also allowed to specify their own views on the subject. The findings of the study show that the levels of understanding of KM concepts among librarians are varied and most of them view KM as the management of information resources, services and systems using technology or specific processes for the capture and use of explicit knowledge, rather sharing and using tacit knowledge. They have positive attitudes towards the applications of knowledge management into academic library practice, and not only because this can bring academic libraries closer to their parent organization, but also because it may help them to survive in an increasingly challenging environment. Although, librarians in the present study acknowledged that they are involved in the practices of knowledge management but these were perceived as basic information management activities. Lack of understanding of knowledge management concepts and its benefits, knowledge sharing culture, top management commitment, incentives and rewards, financial resources and information technology infrastructure are perceived as the major barriers for incorporating knowledge management into academic library practice.  相似文献   
88.
89.
We extended an improved version of the discrete particle swarm optimization (DPSO) algorithm proposed by Liao et al.(2007) to solve the dynamic facility layout problem (DFLP). A computational study was performed with the existing heuristic algorithms, including the dynamic programming (DP), genetic algorithm (GA), simulated annealing (SA), hybrid ant system (HAS), hybrid simulated annealing (SA-EG), hybrid genetic algorithms (NLGA and CONGA). The proposed DPSO algorithm, SA, HAS, GA, DP, SA-EG, NLGA, and CONGA obtained the best solutions for 33, 24, 20, 10, 12, 20, 5, and 2 of the 48 problems from (Balakrishnan and Cheng, 2000), respectively. These results show that the DPSO is very effective in dealing with the DFLP. The extended DPSO also has very good computational efficiency when the problem size increases.  相似文献   
90.
蛋白质糖基化修饰研究进展   总被引:2,自引:0,他引:2  
李军  杜鑫  陈玉银 《科技通报》2009,25(6):773-778,783
蛋白质翻译后修饰是蛋白质组学的一个组成部分,而蛋白质糖基化是生命体中最重要的一种蛋白质翻译后修饰之一。糖基化在细胞免疫、信号传导、蛋白翻译调控、蛋白降解等诸多生物过程中起着重要作用。随着蛋白质组学技术的不断发展,糖基化研究也越来越受到广泛的关注。本文综述了糖基化的分类、在生命体中的作用、最新的研究技术及进展。  相似文献   
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