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41.
The authors explored the possibility that there are different neural consequences, beyond the primary site of brain damage, following perirhinal cortex (PRh) lesions made in different ways. Fos expression was used as a marker for neuronal activation and compared across the forebrains of rats that underwent the different types of surgery. Electrolytic and excitotoxic PRh lesions produced dramatic increases in Fos expression in the cortex, and excitotoxic and aspiration PRh lesions increased Fos expression in the dentate gyrus. These data are consistent with the hypothesis that different lesion methods have separable effects on neural function in regions outside the lesion site that could account for inconsistencies in the literature regarding the behavioral effects of PRh lesions on tests of spatial memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
42.
This study investigated the role of early literacy and behavioral skills in predicting the improvement of children who have experienced reading difficulties in 1st grade. The progress of 146 low-income children whose reading scores in 1st grade were below the 30th percentile was examined to determine (a) how the poorest readers in 1st grade progressed in reading achievement through 4th grade and (b) which emergent literacy and behavioral skills measured in kindergarten predicted differential 4th grade outcomes. Results indicated that the divergence between children who improved and those who did not was established by the end of 2nd grade. Further, individual linguistic skills and behavioral attributes measured in kindergarten contributed substantively to this difference. Implications for intervention timing and educational policy are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
43.
Early Head Start, a federal program begun in 1995 for low-income pregnant women and families with infants and toddlers, was evaluated through a randomized trial of 3,001 families in 17 programs. Interviews with primary caregivers, child assessments, and observations of parent-child interactions were completed when children were 3 years old. Caregivers were diverse in race-ethnicity, language, and other characteristics. Regression-adjusted impact analyses showed that 3-year-old program children performed better than did control children in cognitive and language development, displayed higher emotional engagement of the parent and sustained attention with play objects, and were lower in aggressive behavior. Compared with controls, Early Head Start parents were more emotionally supportive, provided more language and learning stimulation, read to their children more, and spanked less. The strongest and most numerous impacts were for programs that offered a mix of home-visiting and center-based services and that fully implemented the performance standards early. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
44.
Two types of attribution believed to predict anger in married couples were investigated. Wives' anger was expected to be predicted by event-dependent attributions, appraisals based on the unique aspects of one's current situation. Husbands' anger was expected to be predicted by schematic attributions, appraisals based on one's global sentiment in the relationship. Seventy-seven recently married couples attended 2 assessment sessions, and each couple identified 4 incidents pertaining to unresolved relationship issues. Participants rated their event-dependent attributions and their anger prior to a discussion for each incident. They also completed questionnaires regarding schematic attributions and relationship sentiment. Hierarchical linear modeling was used to distinguish between the 2 types of attribution. Strong support was found for the expected gender differences. Results suggest that wives are particularly attentive to the details of interpersonal interaction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
45.
The hydration characteristics and expansion impetus of three kinds of cement paste under free-and confined-curing conditions were investigated, which were respectively mixed with three different kinds of expansive agent at low W/B ratio. The results show that the hydration products of pure cement paste and paste mixed with expansive agent are same, but the amount of hydration products, un-hydrated C3S and C2S are obviously different at the same hydration age. At 3 d age, the amount of CH in pure cement paste is less than that of paste mixed with expansive agent, but it is reverse when at 28 d age. The amount of AFt at 3d and 28d age in pure cement paste is less than those of paste mixed with expansive agent. Regardless of under free- or confined-curing condition, the amount of ettringite produced varies little since 3d age. The joint effect of the tumefaction of gel-ettringite due to water absorption and the expansive pressure on the pore caused by the crystalloid ettringite is the cause of the volume expansion of cement paste, and the former effect is much greater than the latter. LU Lin-nu : Born in 1972 Funded by 973 High-tech Project of China (No. 2001CB610704-2) and the Natural Science Foundation of Hubei Province(No. 2002AB075)  相似文献   
46.
以路由器为核心的IP网络预报避免控制拥塞的实现策略   总被引:3,自引:0,他引:3  
在现有的IP网络基础上如何提高服务质量、如何更好的将IP和ATM两种技术结合起来、如何在IP网络上实现包括实时通信业务在内的综合业务通信,是当前IP领域的研究热点.就目前的研究成果而言主要有两大方向:一是提高分组交换的速度,提高网络带宽,从根本上解决IP网络的质量问题.另一方向是提供完善的流量控制与拥塞避免机制并参照ATM的一些成功技术经验.目前,IP领域的主要问题是如何折中考虑两个因素,即技术的完备复杂性和简单可操作性.本文将研究以路由器为核心构筑的IP网络其预报、避免、控制拥塞的实现策略,包括:各种服务模型的描述、数据包的分类方法、路由器管理拥塞的方法、路由器预报避免拥塞的方法,它们都可以应用于现有网络,并且在逐渐完善。最后,对上述各方法的优缺点进行了比较.  相似文献   
47.
This paper introduces a measuring method of early lateral energy fraction in the scale model experiments. According to the interference principle of half wave length making the high frequency figure-8 directional microphone. With the signal-processing technique, a receiving and analyzing system, for the measurements of lateral energy fraction in the scale model is realized.  相似文献   
48.
Fos, the protein product of the immediate early gene c-fos, was used to map functional circuitry underlying contextual conditioned fear. Male rats were given footshocks in a distinctive context and later tested using freezing as the behavioral measure and compared with no-shock and no-retention-test control groups. An increased number of Fos-immunoreactive neurons was found in the lateral part of the central nucleus and in the anterior basolateral and lateral amygdalar nuclei in the brains of the conditioned-fear group compared with controls. Further, a greater number of Fos-immunoreactive neurons was observed in the right central and anterior basolateral nuclei compared with the number of labeled neurons in these structures on the left. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
49.
The authors studied sex-typing in the kinds (e.g., sports, handicrafts) and social contexts (same- vs. other-sex companions) of children's free time activities, and the links between sex-typed activities and gender development over 2 years. Participants were 200 White, working- and middle-class children (103 girls, 97 boys; mean age = 10.86 years). In annual home interviews, children rated their self-esteem, gender role attitudes and sex-typed personality qualities, academic interests, and school grades. During 7 nightly phone interviews each year, children reported on their activities. Boys were more sex-typed than girls in their peer activities, and children were least sex-typed in their activities with siblings. Sex-typed activities in middle childhood predicted individual differences in gender development in early adolescence (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
50.
挤压模具早期失效起因与处理   总被引:4,自引:0,他引:4  
韩刚 《河北冶金》1997,(5):44-49
从模具的热处理,变形表面压力分布,挤压速度等角度分析了模具早期失效的原因,并提出了防止和减少模具早期失效的措施。  相似文献   
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