Local influence analysis of nonlinear structural equation models

By regarding the latent random vectors as hypothetical missing data and based on the conditional expectation of the complete-data log-likelihood function in the EM algorithm, we investigate assessment of local influence of various perturbation schemes in a nonlinear structural equation model. The basic building blocks of local influence analysis are computed via observations of the latent variables generated by the Metropolis-Hastings algorithm, while the diagnostic measures are obtained via the conformal normal curvature. Seven perturbation schemes, including some perturbation schemes on latent vectors, are investigated. The proposed procedure is illustrated by a simulation study and a real example. Acknowledgment: This research is fully supported by a grant (CUHK 4243/02H) from the Research Grant Council of the Hong Kong Special Administration Region. The authors are indebted to ICPSR and the relevant funding agency for allowing use of their data, and to the Editor and reviewers for their valuable comments for improving the paper.     

Does the right hemisphere take over after damage to Broca's area? the Barlow case of 1877 and its history

In 1877 Thomas Barlow, a London physician, published a remarkable case of functional recovery of speech following brain damage. It involved a 10-year-old boy who had lost his speech, regained it, and lost it again before he died from a disorder that affected his heart and produced embolisms that subsequently affected other organs, including his brain. Examination of the boy's brain revealed two focal regions of softening; one that affected Broca's area and the left facial-motor area, and another, which occurred weeks later, in the homologous regions of the right hemisphere. Although Barlow was most concerned with motor deficits, others at the turn of the century began to cite this case as strong evidence that the corresponding region of the right hemisphere can take over speech functions for Broca's area on the left. Whether this case really provides good support for functional takeover or vicariation theory is critically evaluated in the light of contemporary research, including PET scan studies involving damage to Broca's speech region.     

健全社区卫生服务功能与防控"非典"传播的理性思考

针对我国当访“非典”防治工作的严竣形势,对健全社区卫生服务“六位一体”功能与防控“非典”传播问题进行哲学思考,着重在健全社区卫生服务功能是防控“非典”传播的客观要求;社区卫生服务功能不全将会对防控“非典”工作产生不利影响;构筑防控“非典”传播的有效机制和基础防线,必须健全社区卫生服务功能等方面作了分析论述。     

Ronald Dworkin on Abortion and Assisted Suicide

In the first part of this article, I raisequestions about Dworkin's theory of theintrinsic value of life and about the adequacyof his proposal to understand abortion in termsof different ways of valuing life. In thesecond part of the article, I consider hisargument in ``The Philosophers' Brief on AssistedSuicide', which claims that the distinctionbetween killing and letting die is morallyirrelevant, the distinction between intendingand foreseeing death can be morally relevantbut is not always so. I argue that thekilling/letting die distinction can be relevantin the context of assisted suicide, but alsoshow when it is not. Then I consider why theintention/foresight distinction can be morallyirrelevant and conclude by presenting analternative argument for physician-assistedsuicide.     

Function word repetitions emerge when speakers are operantly conditioned to reduce frequency of silent pauses

Beattie and Bradbury (1979) reported a study in which, in one condition, they punished speakers when they produced silent pauses (by lighting a light they were supposed to keep switched off). They found speakers were able to reduce silent pauses and that this was not achieved at the expense of reduced overall speech rate. They reported an unexpected increase in word repetition rate. A recent theory proposed by Howell, Au-Yeung, and Sackin (1999) predicts that the change in word repetition rate will occur on function, not content words. This hypothesis is tested and confirmed. The results are used to assess the theory and to consider practical applications of this conditioning procedure.     

The early acquisition of verb meaning in German by normally developing and language impaired children

The research reported here focuses on the early acquisition of event structure in German. Based on longitudinal studies from 5 normally developing (ND) and 6 language-impaired (LI) children, a model of "event structural bootstrapping" is presented that spells out how ND children log into the verb lexicon. They project a target-consistent event tree, depicting the head-of-event of transitions. Young LI children, failing to employ this bootstrapping strategy, resort to radically underspecified event representations. The results from a truth-value judgment experiment with 16 ND and 16 LI children showed that ND children perform correctly on transitional verbs, while LI children perform at chance level on the same tasks. These findings are accounted for by the model of event structural bootstrapping to the extent that LI children lack an explicit representation of the head-of-event.     

大学毕业生的职业期望及其影响因素研究

本研究对当代大学生职业期望所包括的关键因素以及各因素之间的结构模式进行了深入分析,从职业动机、自我意识、环境意识以及个人的职业发展计划等多种不同角度对影响职业期望的因素进行了有益的探索,并在此基础上建立了"当代大学生职业期望的初步模型".     

Wisdom and Life Experience: How Grandfathers Mentor Their Grandchildren

This exploratory study uses qualitative methods to focus on the largely unexamined role of the grandfather and to examine men's experiences as grandfathers. We gathered information through both surveys and individual interviews to explore men's feelings and attitudes toward the grandfather role. Of the 51 grandfathers that completed a survey, 20 participated in interviews. Our examination of the data collected reveals the life lessons men teach their grandchildren. The grandfathers in this study expressed strong desires for purposeful involvement in their grandchildren's lives and indicated desires for transferring values to grandchildren and teaching interpersonal relationships. Through this involvement, they educate through life experiences and serve as mentors for their grandchildren. We suggest that this mentoring role makes a positive contribution to the lives of grandchildren and to the identity of grandfathers.     

Effect of Aging on Processes of Motor Inhibition

The processes of inhibiting uninstructed motor responses were examined to identify age differences. Younger adults (n = 40) and older adults (n = 38) participated in two experiments using the Stimulus‐Response Compatibility task. They were asked to push the switch on the side contralateral to the stimulus. The results indicated that responses induced by visual stimuli were gradually inhibited as a result of repeated trials on the contralateral (not‐induced) side, and no age differences were noted. The addition of a color‐discrimination task to the Stimulus‐Response Compatibility task inhibited impulsive response induced by visual stimuli in younger adults only. These results indicate that certain processes of inhibiting motor responses are affected by aging, whereas other processes remain unaffected.