Chicks Injected with Antisera to either S-100α or S-100β Protein Develop Amnesia for a Passive Avoidance Task

The cellular expression of S-100β protein is upregulated in Alzheimer's disease and in Down's syndrome, and this protein has been implicated in memory-related processes in laboratory animals. However, the possibility that the α subunit of S-100 is also involved in memory has not yet been examined. In the present study, day-old black Australorp white Leghorn cockerel chicks (Gallus domesticus) received injections of monoclonal antisera to S-100α (1:50) or S-100β (1:500) into each hemisphere immediately after training on a one-trial passive avoidance task. The chicks displayed significantly lower retention levels than control birds that had been injected with antisera to carbonic anhydrase, or with saline (p< .01). S-100α antisera had an amnestic effect when injected between 0 and 20 min after training, with memory deficits occurring from 30 min postlearning, at the point of transition between the A and the B phases of the Gibbs-Ng intermediate memory stage. By contrast, the S-100β antisera needed to be injected either 5 min before or immediately after training and produced amnesia 10 min earlier, at the start of the A phase of the intermediate memory stage. We conclude that the two subunits of the S-100 protein are required at different points in the sequence of events leading to the consolidation of passive avoidance memory.     

The Stability of Literacy-Related Cognitive Contributions to Chinese Character Naming and Reading Fluency

The present study examined the developmental issue of cognitive factors that explain Chinese literacy. Phonological awareness, rapid automatized naming, short-term memory, orthographic awareness and morphological awareness and two literacy tasks (character naming and reading fluency) were administered to 408 second-graders, 428 fourth-graders and 496 six-graders. Results from linear regression analysis and path analysis model showed that the five reading-related cognitive constructs explained unique variances in character naming. Second, character naming is primary for reading fluency after controlling other cognitive constructs; third, the relation between the cognitive factors and literacy changes significantly as a function of reading skills. Results give a clear direction to understanding Chinese reading development.     

时态结构中的恒常联系因果学习

人工智能研究中,行动这一概念通常在理论框架中有完全的定义。然而,现实中的行动有时难以完全刻画。智能体需要从过去的经验观察中习得行动的后果。本文提出一种基于时态结构的行动一结果学习理论。在自然数时间结构中,智能体通过观察过去的恒常联系建立因果关系。智能体依据己建立的因果关系指导将来的行动。同时,我们给出关于该理论的一个完全的逻辑演绎系统,并给出基于该逻辑的智能体行动的有效算法。     

阅读材料的呈现方式对儿童阅读活动的影响

本研究采用传统印刷文本、普通电子文本和超文本导航模式考察阅读材料的呈现方式对儿童阅读活动的影响.研究结果表明:(1)在三种呈现方式条件下,高阅读水平者的阅读成绩显著优于低水平者;女生成绩显著优于男生;(2)阅读材料的不同呈现方式对儿童阅读理解无显著影响;(3)在三种呈现方式中,儿童对超文本的正向评价要优于传统印刷文本和普通电子文本.这表明大部分儿童可以在短时间内接受,并熟悉非线性文本方式.     

医疗价格过度增长的管制原因分析

医疗服务的准公共产品特征说明医疗价格问题不能完全由市场来解决,政府必须对医疗价格进行管制。造成医疗价格高昂的原因是多样的和复杂的,基于对医疗价格的政府管制现状分析,认为对医疗价格的管制不善,是导致中国高昂医疗价格的原因之一,并且提出了对医疗价格进行管制的制度框架。     

低出生体重与代谢综合征

低出生体重是发生成年期代谢综合征的高危因素。“代谢程序化”与“营养程序化”概念的提出对人们从多层面认识该现象的内在机制有重要指导作用。随着对发生机制研究的深入,人们终将找到预防低出生体重发生成年期代谢综合征的早期干预措施。     

气质和儿童同伴交往类型关系的研究

该文采用问卷法和社会测量法相结合的方法,以班级为单位对484名3~9岁儿童的气质和同伴关系类型的关系进行研究。结果表明:3~9岁儿童同伴关系类型已形成分化,其中被忽视儿童和被拒绝儿童所占总体样本的比例分别为16.9%和9.6%,比例较高值得重视。儿童气质对同伴交往类型的形成影响很大,四种同伴关系交往类型在气质各维度上方差检验都达到了差异显著,有着明显不同的气质特点。     

制止高官参与封建迷信、伪科学活动(二)

高官支持、带头搞伪科学、封建迷信,影响很坏高官们这些做法之所以影响很坏,是由于以下一些因素在起作用。(一)组织性和纪律观念的误用全国解放半个多世纪了。现在我国广大干部都是在党的教育下成长起来的,有的本身就是共产党员,他们都有很强的组织性和纪律观念,一般对上级领导人的批示和指示都不打折扣地贯彻执行。这无疑是对的。但另一方面,党的民主集中制原则规定,个人服从组织,少数服从多数,下级服从上级,全党服从中央;同时还规定,党员“对党的决议和政策如有不同意见,在坚决执行的前提下,可以声明保留,并且可以把自己的意见向党的上级…     

从《无神论——绪论》看宗教自由和反无神论观念

《无神论》是美国马丁(MICHAEL MARTIN)教授写的一部名著,副标题《哲学的合理性证明》,1990年出版。书前有一篇颇长的《绪论》,针对一些有神论者的批评,作了扼要的回应,从中可以看出当代西方宗教神学是如何抨击无神论的,以及他对这些抨击所作的逻辑反驳和对无神论的合理性证明。我特别感兴趣的问题,还有作者无意中透露出来的美国的意识形态和宗教自由问题。作者回忆说,他幼年受家庭影响,倾向无神论,但同时知道,无神论在美国民众的心目中是很坏的,因为“他们大多数人都信仰上帝”。记得“三年级的一天,我向一个有同情心的指导顾问透露…