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1.
From carrots to frogs to sheep and finally to humans, the history of cloning is a fascinating study of the interplay between science and popular culture. Imagination and discovery provide mutual impetus in the evolving science and cultural phenomenon of cloning. Its history is a paradigm of science unfiction: What once belonged unequivocally on the pages of science fiction is now emerging in flesh and blood. Writers, movie producers, ethicists, and all manner of social commentators, no less than scientists, have all participated in the creation of the human clone as an idea and as a biological entity. While the clone stands apart as having only one genetic parent, it truly is a brainchild of multifarious origins.  相似文献   
2.
Influence analysis is an important component of data analysis, and the local influence approach has been widely applied to many statistical models to identify influential observations and assess minor model perturbations since the pioneering work of Cook (1986) . The approach is often adopted to develop influence analysis procedures for factor analysis models with ranking data. However, as this well‐known approach is based on the observed data likelihood, which involves multidimensional integrals, directly applying it to develop influence analysis procedures for the factor analysis models with ranking data is difficult. To address this difficulty, a Monte Carlo expectation and maximization algorithm (MCEM) is used to obtain the maximum‐likelihood estimate of the model parameters, and measures for influence analysis on the basis of the conditional expectation of the complete data log likelihood at the E‐step of the MCEM algorithm are then obtained. Very little additional computation is needed to compute the influence measures, because it is possible to make use of the by‐products of the estimation procedure. Influence measures that are based on several typical perturbation schemes are discussed in detail, and the proposed method is illustrated with two real examples and an artificial example.  相似文献   
3.
One component of individual risk for alcoholism may involve cognitive vulnerabilities prodromal to alcoholism onset. This prospective study of 198 boys followed between 3 and 14 years of age evaluated neurocognitive functioning across three groups who varied in familial risk for future alcoholism. Measures of intelligence, reward-response, and a battery of neuropsychological executive and cognitive inhibitory measures were used. Executive functioning weaknesses were greater in families with alcoholism but no antisocial comorbidity. IQ and reward-response weaknesses were associated with familial antisocial alcoholism. Executive function effects were clearest for response inhibition, response speed, and symbol-digit modalities. Results suggest that executive deficits are not part of the highest risk, antisocial pathway to alcoholism but that some executive function weaknesses may contribute to a secondary risk pathway.  相似文献   
4.
Influence analysis of structural equation models with polytomous variables   总被引:2,自引:0,他引:2  
The estimation of model parameters in structural equation models with polytomous variables can be handled by several computationally efficient procedures. However, sensitivity or influence analysis of the model is not well studied. We demonstrate that the existing influence analysis methods for contingency tables or for normal theory structural equation models cannot be applied directly to structural equation models with polytomous variables; and we develop appropriate procedures based on the local influence approach of Cook (1986). The proposed procedures are computationally efficient, the necessary bits of the proposed diagnostic measures are readily available following an usual fit of the model. We consider the influence of an individual cell frequency with respect to three cases: when all parameters in an unstructured model are of interest, when the unstructured polychoric correlations are of interest, and when the structural parameters are of interest. We also consider the sensitivity of the parameters estimates. Two examples based on real data are presented for illustration.The work described in this paper was partially supported by a Chinese University of Hong Kong Postdoctoral Fellows Scheme and a grant from the Research Grants Council of the Hong Kong Special Administrative Region, China (RGC Ref. No. CUHK4186/98P). We are indebted to P.M. Bentler and M.D. Newcomb for providing the data set, Michael Leung for his assistance, and the Editor and the referees for some very valuable comments.  相似文献   
5.
Theories of boredom assert that boredom is a product of situational meaninglessness. We conducted two studies to test if the perceived meaningfulness of a situation is associated with state boredom, above and beyond sadness, personality traits, and boredom proneness. In Study 1, 105 participants (72.4% female: mean age?=?33.9 years, SD?=?17.5) described situations in which they experienced boredom, no boredom, engagement, or sadness. They then rated the level of state boredom, sadness, and meaninglessness that they experienced in that situation. As hypothesized, state boredom was associated with situational meaninglessness, before and after controlling for sadness. In Study 2, 148 participants (73.0% female; mean age?=?19.2 years, SD?=?1.8) first provided baseline data on personality traits and boredom proneness. Through a smartphone app-based experience-sampling method, they then responded to a brief questionnaire multiple times a day, across 7 days. The questionnaire asked about the nature of their current activity, whether the activity was done alone or with other people, and their affective state. Results from multilevel modelling of 3022 entries suggest that perceived meaningfulness of the activity was negatively associated with state boredom, above and beyond sadness, personality, and boredom proneness. We also found that being with others during the activity acted as a moderator; activities lower in perceived meaningfulness were associated with higher ratings of state boredom when done with others than when done alone. These results demonstrate that perceptions of meaninglessness characterize state boredom.  相似文献   
6.
The present study examined children’s support-seeking of mothers (SSM) as a moderator of the association between maternal emotion socialization responses and children’s emotion management. Participants included 119 mother–child dyads (63 boys, M age = 9.61 years, 73.1 % Caucasian). Maternal emotion socialization was assessed via observed mother–child interactions and child report. Analyses indicated several main effects such that child-reported maternal reward responses were associated with stronger child emotion management, whereas perceived maternal punishment and neglect were associated with poorer child emotion management. Regarding the significant interactions, observed maternal general unsupportive socialization responses were negatively associated with emotion management. Additionally, for children low in SSM, child-reported maternal overriding of children’s emotions was positively associated with better emotion management. Support-seeking of mothers may mitigate the risk of some unsupportive maternal socialization responses and may be an adaptive strategy in middle childhood in particular contexts.  相似文献   
7.
Speech processing involves rapid decoding and construction of meaning from a transitory acoustic signal. Because older adults have been found to be slower in performing many cognitive tasks, we hypothesized that they may have difficulty in immediate recall for speech of increasing input rate. Two experiments are reported in which both older and younger participants listened to and immediately recalled sentences that were systematically varied in speech rate and number of propositions. Although recall performance of the older adults showed a disproportionate decline when speech rate was increased, older adults, as well as the younger adults, were able to recall sentences of increasing propositional densities. We also found that the tendency to recall a greater proportion of main ideas than details (the levels effect) was enhanced by increased propositional density, and depressed by increased speech rate and increased age. These results are discussed in terms of an age-related change in the rate at which information can be processed in working memory.  相似文献   
8.
Two experiments tested whether cyberostracism increases people’s perceived moral impurity and their tendency to purchase cleansing products. In both experiments, participants were first either ostracized or included in a web-based social interaction. Next, they completed self-report measures to assess their perceived moral impurity and tendency to purchase cleansing products. The results showed that participants who were ostracized reported a higher level of moral impurity and a higher tendency to purchase cleansing products. These findings advance our current understanding on the effect of online social interaction on people’s moral self-perception.  相似文献   
9.
10.
This study assessed engaged lifestyle activities (e.g., volunteering, traveling, and public speaking) for centenarians of the Georgia Centenarian Study. A total of 285 centenarians and near-centenarians (i.e., 98 years and older) and their proxy informants participated in this study. The Mini-Mental Status Examination (MMSE) was assessed for all centenarians, and proxy informants reported on lifestyle activities and personality traits of the centenarians. Results suggested that participants who had volunteered, traveled, and those who had given public talks and balanced their checkbooks were more likely to show relatively high mental status scores (i.e., MMSE > 17). Personality traits were found to be moderators in the relationship between engaged lifestyle and mental status: Participants with high levels of Emotional Stability, Extraversion, Openness, and Conscientiousness and with high levels of engaged lifestyle were more likely to show relatively high mental status scores (i.e., MMSE > 17), whereas participants with low levels of Emotional Stability, Extraversion, Openness, Agreeableness, and Conscientiousness and with low levels of engaged lifestyle were more likely to show relatively low mental status scores (i.e., MMSE < 18). The results suggest that engaged lifestyle, particularly in combination with personality traits, plays an important role in the level of cognitive functioning among oldest old adults.  相似文献   
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