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41.
    
The current paper presents an integrated formal model of typical and atypical development based on the mechanisms of mutualism and resource competition. The mutualistic network model is extended with the dynamics of competition for limited resources, such as time and environmental factors. The proposed model generates patterns that resemble established phenomena in cognitive development: the positive manifold, developmental phases, developmental delays and lack of early indicators in atypical development, developmental regression, and “quasi-autism” caused by extreme environmental deprivation. The presented modeling framework fits a general movement towards formal theory construction in psychology. The model is easy to replicate and develop further, and we offer several avenues for future work.  相似文献   
42.
    
Career academies promote smaller learning communities within high schools, creating personalized learning environments while promoting students’ readiness for college and careers. After describing the career academy structure, we present four research-based aspects that can assist school leaders and teachers in developing and implementing academies. We include practical examples from the Metro Nashville Public Schools, noting how educators have collaborated with civic agencies, businesses, and postsecondary partners to increase the graduation rate and improve student learning outcomes. Career academies can be effective in preparing students for college and careers, while also providing economic benefits to the community.  相似文献   
43.
    
One influential explanation of the development of verbal short-term memory in children argues that short-term memory capacity is a direct function of speech rate. This theory predicts that children with pathologically slow speech will show reduced verbal short-term memory capacity and will show less evidence of speech-base coding on verbal memory tasks. To test this prediction, verbal short-term memory span was assessed using a task that did not require a verbal response in 37 speech-disordered children and 37 age- and sex-matched controls (age range 4-15 years). The speech-disordered group had a significantly lower short-term memory capacity, a smaller word length effect, and reduced speech-motor activity during rehearsal periods. Covariance analyses revealed that these differences were not a function of general intellectual or motor speed differences between the groups, and that speech rate as a covariate abolished group differences in short-term memory. These results suggest that speech rate may be a causal determinant of verbal short-term memory capacity.  相似文献   
44.
Donald R. McCoy The National Archives: America's Ministry of Documents, 1934-1968 (Chapel Hill, Yniversity of North Carolina Press, 1978—$19.00)

Madeleine B. Stern Books and Book People in 19th Century America (New York: R.R. Bowker, 1978—$25.00)

Susan Otis Thompson American Book Design and William Morris (New York: Bowker, 1977—$29.95)  相似文献   
45.
46.
We demonstrate a highly integrated microfluidic chip with the function of DNA amplification. The integrated chip combines giant electrorheological-fluid actuated micromixer and micropump with a microheater array, all formed using soft lithography. Internal functional components are based on polydimethylsiloxane (PDMS) and silver∕carbon black-PDMS composites. The system has the advantages of small size with a high degree of integration, high polymerase chain reaction efficiency, digital control and simple fabrication at low cost. This integration approach shows promise for a broad range of applications in chemical synthesis and biological sensing∕analysis, as different components can be combined to target desired functionalities, with flexible designs of different microchips easily realizable through soft lithography.  相似文献   
47.
The coronal and sagittal plane leg movements of 24 experienced male cyclists were assessed using video analysis while cycling on a Kingcycle windload simulator. The cyclists were grouped into those with a history of injury and an asymptomatic group on the basis of self-reported injury status. The ages, cycling experience, competition distances and competition speeds of the two groups were compared using Student's t-test. No significant differences (P < 0.05) were found for any of these variables. The maximum and minimum shank adduction, shank adduction velocities, knee flexion and ankle dorsiflexion values were also compared using Student's t-test. Significant differences were found at the point of maximum adduction (1.9 degrees; P = 0.019) and minimum dorsiflexion (4.9 degrees; P = 0.014). These differences indicated more dorsiflexion and greater abduction on the part of the symptomatic cyclists, supporting previous research that found that cyclists with a history of injury differ from those without a history of injury in the coronal plane leg movement patterns they adopt. Also, the most extreme medial position of the knee relative to the ankle occurred during knee extension. This supports the potential injury mechanism proposed by Francis (1986), which had previously only been examined using coronal plane kinematics.  相似文献   
48.
    
An attempt was made to formulate a theoretical framework of leadership forces in school organisations, which includes bureaucratic linkage, cultural linkage, tight coupling and loose coupling. Two instruments, the School Values Inventory (SVI) and the Teachers' School Life Questionnaire (TSLQ), were created and developed for this study to assess the administrative values espoused by principals and teachers' feelings about school life. Based on data collected from 1395 teachers from a randomly selected sample of 39 secondary schools in Hong Kong, the four scales of leadership forces in secondary schools were confirmed. Findings show that cultural linkage and loose coupling were the most effective leadership forces to bind people together within schools, tight coupling the next, but the use of bureaucratic linkage was controversial.  相似文献   
49.
The Pitt-Kraft model of buying versus photocopying results in a small, but complex, nonlinear program. This paper identifies a Kuhn-Tucker point and demonstrates that for certain parameter values it is not optimal. A policy generation procedure is presented; the purpose is to prevent convergence of a primal algorithm to this inferior policy, which satisfies the Kuhn-Tucker optimality conditions.  相似文献   
50.
Women’s access to academic careers has been historically limited by discrimination and cultural constraints. Comprehensive information about gender inequality within disciplines is needed to understand the problem and target remedial action. India is the fifth largest research producer but has a low international index of gender inequality and so is an important case. This study assesses gender inequalities in Indian journal article publishing in 2017 for 186 research fields. It also seeks overall gender differences in interests across academia by comparing the terms used in 27,710 articles with an Indian male or female first author. The data show that there are at least 1.5 male first authors per female first author in each of 26 broad fields and 2.8 male first authors per female first author overall. Compared to the USA, India has a much lower share of female first authors but smaller variations in gender differences between broad fields. Dentistry, Economics and Maths are all more female in India, but Veterinary is much less female than in the USA. There is a tendency for males to research thing-oriented topics and for females to research helping people and some life science topics. More initiatives to promote gender equality in science are needed to address the overall imbalance, but care should be taken to avoid creating the larger between-field gender differences found in the USA.  相似文献   
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