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Summary. In many biomedical studies, covariates are subject to measurement error. Although it is well known that the regression coefficients estimators can be substantially biased if the measurement error is not accommodated, there has been little study of the effect of covariate measurement error on the estimation of the dependence between bivariate failure times. We show that the dependence parameter estimator in the Clayton–Oakes model can be considerably biased if the measurement error in the covariate is not accommodated. In contrast with the typical bias towards the null for marginal regression coefficients, the dependence parameter can be biased in either direction. We introduce a bias reduction technique for the bivariate survival function in copula models while assuming an additive measurement error model and replicated measurement for the covariates, and we study the large and small sample properties of the dependence parameter estimator proposed.  相似文献   
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This paper documents situations where the variance inflation model for outliers has undesirable properties. The model is commonly used to accommodate outliers in a Bayesian analysis of regression and time series models. The alternative approach provided here does not suffer from these undesirable properties but gives inferences similar to those of the variance inflation model when this is appropriate. It can be used with regression, time series, and regression with correlated errors in a unified way, and adheres to the scientific principle that inference should be based on the data after obvious outliers have been discarded. Only one parameter is required for outliers; it is interpretable as the a priori willingness to remove observations from the analysis.  相似文献   
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Tattling on siblings was observed in 40 families with 2- and 4-year-old children. All but 5 children reported sibling misbehaviour to parents with younger siblings tattling largely to recruit parental help in resolving conflict issues, and older siblings tattling both in the context of conflict and merely to inform parents of their siblings' misbehaviour. Parents rarely reprimanded children for tattling, but either ignored it, or responded to information in tattlers' reports regardless of context or whether older or younger children tattled. Children did not tattle equally on all sibling transgressions, but emphasized physical aggression and property damage, issues that also elicited parental discipline. Tattling is discussed in relation to children's understanding of the dynamics and moral standards of family life.  相似文献   
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What strengths and talents make an outstanding child care worker? How can these qualities be measured? How can one predict whether an individual will succeed as a child care worker? The authors attempt to answer these questions by focusing on the "life themes" of highly rated child care workers and using a technique to measure these themes.  相似文献   
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We examine the effect of medical care and living conditions on children's physical and psychological well-being. We develop a causal model in which living conditions (including the socioeconomic status of the family and the social-psychological aspects of family functioning) may affect well-being both directly, and indirectly through medical care. We find that families in the higher social classes and families that function well tend to go to large prepaid groups where they receive good medical care. High quality technical care of illness, in turn, improves physical health. The quality of psychotherapeutic care, on the other hand, has no effect on psychological well-being. For this aspect of health, the effect of living conditions is largely direct, rather than indirect by way of medical care. Families characterized by high levels of functioning have children who are psychologically healthy. In addition, physical health affects psychological well-being, but not vice versa.  相似文献   
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European food retailers have increased their scale and scope while concentrating sales into large stores. Strategic implications include the need for scale to compete and organisational relationships to move from supply push to demand pull retailing. Consequences are different for private label and for branded manufacturers, who must respond to the demands of retail supply chains whilst retaining control of product development. Further concentration in both sectors is likely. Consumers are more mobile, but more captive to the retailer in store. Public policy makers are challenged to find new measures of retail power and both allow for innovation and ensure equitable shopping opportunities.  相似文献   
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Understanding the risk of biological invasions associated with particular transport pathways and source regions is critical for implementing effective biosecurity management. This may require both a model for physical connectedness between regions, and a measure of environmental similarity, so as to quantify the potential for a species to be transported from a given region and to survive at a destination region. We present an analysis of integrated biosecurity risk into Australia, based on flights and shipping data from each global geopolitical region, and an adaptation of the “range bagging” method to determine environmental matching between regions. Here, we describe global patterns of environmental matching and highlight those regions with many physical connections. We classify patterns of global invasion risk (high to low) into Australian states and territories. We validate our analysis by comparison with global presence data for 844 phytophagous insect pest species, and produce a list of high‐risk species not previously known to be present in Australia. We determined that, of the insect pest species used for validation, the species most likely to be present in Australia were those also present in geopolitical regions with high transport connectivity to Australia, and those regions that were geographically close, and had similar environments.  相似文献   
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