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351.
This study examines face‐scanning behaviors of infants at 6, 9, and 12 months as they watched videos of a woman describing an object in front of her. The videos were created to vary information in the mouth (speaking vs. smiling) and the eyes (gazing into the camera vs. cueing the infant with head turn or gaze direction to an object being described). Infants tended to divide their attention between the eyes and the mouth, looking less at the eyes with age and more at the mouth than the eyes at 9 and 12 months. Attention to the mouth was greater on speaking trials than on smiling trials at all three ages, and this difference increased between 6 and 9 months. Despite consistent results within subjects, there was considerable variation between subjects. This raises the question of whether a developmental “norm” of face scanning in infancy ought to be pursued. Rather, these data add to emerging evidence suggesting that individual differences in face scanning might reliably predict aspects of later development.  相似文献   
352.
Little is known about problem gambling in older adults, particularly when gambling problems only commence late in life. Knowledge of pathways to later life problem gambling can assist prompt and effective interventions for vulnerable older adults. This study builds on a generic Pathways Model. It proposes routes to problem gambling for individuals aged 55 years and above, with a particular focus on late-life, rather than lifetime problem gambling. Gambling-related risk and protective factors/correlates were extracted from the literature based on the extent to which the studies were senior-specific. Common themes were then identified and classified into 3 main clusters: 1 concerning individual vulnerability factors, a 2nd concerning social and environmental factors, and a 3rd concerning factors affecting behavioural regulation.  相似文献   
353.
Solving problems in parameter redundancy using computer algebra   总被引:1,自引:0,他引:1  
A model, involving a particular set of parameters, is said to be parameter redundant when the likelihood can be expressed in terms of a smaller set of parameters. In many important cases, the parameter redundancy of a model can be checked by evaluating the symbolic rank of a derivative matrix. We describe the main results, and show how to construct this matrix using the symbolic algebra package Maple. We apply the theory to examples from the mark-recapture field. General code is given which can be applied to other models.  相似文献   
354.
This article provides a narrative analysis of one written account of jealousy. The analysis assumes the importance of cultural, historical, and social context in making sense of the experience of jealousy. Our analysis was organized around the positioning triad of story line, positioning, and social acts. We were particularly guided by a structural Labovian (1972) approach to the basic story line. The story we examined was chosen for its useful illustration of three subject positions: victim, avenger, and outsider. The analysis highlights the way in which jealousy is constituted through a sequential unfolding of events that are made meaningful within the context of local mores, adolescent romance, and revenge.  相似文献   
355.
Group sequential trialswith time to event end points can be complicated to design. Notonly are there unlimited choices for the number of events requiredat each stage, but for each of these choices, there are unlimitedcombinations of accrual and follow-up at each stage that providethe required events. Methods are presented for determining optimalcombinations of accrual and follow-up for two-stage clinicaltrials with time to event end points. Optimization is based onminimizing the expected total study length as a function of theexpected accrual duration or sample size while providing an appropriateoverall size and power. Optimal values of expected accrual durationand minimum expected total study length are given assuming anexponential proportional hazards model comparing two treatmentgroups. The expected total study length can be substantiallydecreased by including a follow-up period during which accrualis suspended. Conditions that warrant an interim follow-up periodare considered, and the gain in efficiency achieved by includingan interim follow-up period is quantified. The gain in efficiencyshould be weighed against the practical difficulties in implementingsuch designs. An example is given to illustrate the use of thesetechniques in designing a clinical trial to compare two chemotherapyregimens for lung cancer. Practical considerations of includingan interim follow-up period are discussed.  相似文献   
356.
Examples of divergence between the intended (stated) and actual consequences of government intervention in the marketplace abound. In this paper, two legislative attempts to specify wage rates on government contracts are analyzed. The Davis-Bacon Act has been successful in forcing government contractors to pay the prevailing union wage rate. In contrast, the Walsh-Healey Act has been ineffective in establishing minimum wage scales on most government contracts. Analysis indicates that the success of one and the failure of the other is due to differences in enforcement costs, special interest group support, the concentration of opposition, and the narrower scope of Davis-Bacon.  相似文献   
357.
358.
For diseases with more than one risk factor, the sum of probabilistic estimates of the number of cases caused by each individual factor may exceed the total number of cases observed, especially when uncertainties about exposure and dose response for some risk factors are high. In this study, we outline a method of bounding the fraction of lung cancer fatalities not due to specific well-studied causes. Such information serves as a "reality check" for estimates of the impacts of the minor risk factors, and, as such, complements the traditional risk analysis. With lung cancer as our example, we allocate portions of the observed lung cancer mortality to known causes (such as smoking, residential radon, and asbestos fibers) and describe the uncertainty surrounding those estimates. The interactions among the risk factors are also quantified, to the extent possible. We then infer an upper bound on the residual mortality due to "other" causes, using a consistency constraint on the total number of deaths, the maximum uncertainty principle, and the mathematics originally developed of imprecise probabilities.  相似文献   
359.
Previous studies of problem gamblers portray this group as being almost exclusively male. However, this study demonstrates that females comprised 46% of the population ( n = 1,520) of persons who sought assistance due to concerns about their gambling from the publicly-funded BreakEven counselling services in the state of Victoria, Australia, in one 12-month period. This suggests that the model of service delivery which is community based counselling on a non-residential basis may be better able to attract female clients than treatment centres where males predominate such as veterans centres. A comparative analysis of the social and demographic characteristics of female and male gamblers within the study population was undertaken. As with previous studies, we have found significant differences between males and females who have sought help for problems associated with their gambling. Gender differences revealed in this study include females being far more likely to use electronic gaming machines (91.1% vs. 61.4%), older (39.6 years vs. 36.1 years), more likely to be born in Australia (79.4% vs. 74.7%), to be married (42.8% vs. 30.2%), living with family (78.9% vs. 61.5%) and to have dependent children (48.4% vs. 35.7%), than males who present at these services. Female gamblers (A$7,342) reported average gambling debts of less than half of that owed by males (A$19,091). These gender differences have implications for the development and conduct of problem gambling counselling services as it cannot be assumed that models of service which have demonstrated effectiveness with males will be similarly effective with females.  相似文献   
360.
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