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61.
Individual differences in infants’ engagement with their environment manifest early in development and are noticed by parents. Three views have been advanced to explain differences in seeking novel stimulation. The optimal stimulation hypothesis suggests that individuals seek further stimulation when they are under‐responsive to current sensory input. The processing speed hypothesis proposes that those capable of processing information faster are driven to seek stimulation more frequently. The information prioritization hypothesis suggests the differences in stimulation seeking index variation in the prioritization of incoming relative to ongoing information processing. Ten‐month‐old infants saw 10 repetitions of a video clip and changes in frontal theta oscillatory amplitude were measured as an index of information processing speed. Stimulus‐locked P1 peak amplitude in response to checkerboards briefly overlaid on the video at random points during its presentation indexed processing of incoming stimulation. Parental report of higher visual seeking did not relate to reduced P1 peak amplitude or to a stronger decrease in frontal theta amplitude with repetition, thus not supporting either the optimal stimulation or the processing speed hypotheses. Higher visual seeking occurred in those infants whose P1 peak amplitude was greater than expected based on their theta amplitude. These findings indicate that visual sensory seeking in infancy is explained by a bias toward novel stimulation, thus supporting the information prioritization hypothesis.  相似文献   
62.
This paper focuses on bivariate kernel density estimation that bridges the gap between univariate and multivariate applications. We propose a subsampling-extrapolation bandwidth matrix selector that improves the reliability of the conventional cross-validation method. The proposed procedure combines a U-statistic expression of the mean integrated squared error and asymptotic theory, and can be used in both cases of diagonal bandwidth matrix and unconstrained bandwidth matrix. In the subsampling stage, one takes advantage of the reduced variability of estimating the bandwidth matrix at a smaller subsample size m (m < n); in the extrapolation stage, a simple linear extrapolation is used to remove the incurred bias. Simulation studies reveal that the proposed method reduces the variability of the cross-validation method by about 50% and achieves an expected integrated squared error that is up to 30% smaller than that of the benchmark cross-validation. It shows comparable or improved performance compared to other competitors across six distributions in terms of the expected integrated squared error. We prove that the components of the selected bivariate bandwidth matrix have an asymptotic multivariate normal distribution, and also present the relative rate of convergence of the proposed bandwidth selector.  相似文献   
63.
In this article, we consider the prediction of future failure times based on Type-I hybrid censored samples. Point predictors and prediction intervals using different procedures are discussed for a general model. The exponential and Rayleigh distributions are used as illustrative examples to show the most simplified forms of the so obtained predictors as well as prediction intervals. Intensive simulation study and a real life dataset are presented to illustrate our findings and results.  相似文献   
64.
Four hundred and seventy-nine undergraduates reported on family discussions about the 2016 election that occurred over that same year’s Thanksgiving break. Family Communication Patterns Theory was used to predict the perceived outcomes of such discussion on family members. Higher conversation orientation predicted a more positive perceived effect of political talk on family closeness. Perceived similarity of political views partially moderated the relationship between conformity orientation and perceived effect of political talk on family closeness. Reported stress levels since the election were negatively predicted by the perceived (positive) effect of political talk on family closeness. Practical and theoretical implications for families and political socialization processes are discussed.  相似文献   
65.
Previous research on generativity, the desire to leave a legacy through establishing and guiding the next generation, has focused primarily on family life and civic engagement as pathways to midlife generativity. This paper proposes that intrinsically rewarding work can also be associated with a heightened sense of generativity in midlife. We test this hypothesis with data (n = 369 employed individuals, approximately 43 years old) from the 2010 wave of the Edmonton Transitions Study. Civic engagement was positively associated with midlife generativity, as predicted, but the hypothesized positive relationship between generativity and perceived parenting success was not found. Taking into account civic engagement and perceived parenting success, and controlling on a range of other variables, intrinsically rewarding work was positively associated with midlife feelings of generativity.  相似文献   
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Using telephone surveys of business/financial journalists in the United States (n = 200), this research investigates the agenda-building role of social media content in journalists’ work. Understanding that more non-public relations content from user-generated and social network sites, like YouTube and Twitter, are fast becoming resources for journalists to get story ideas, break scandals, and find sources, we began this scholarly work to determine the frequency of such uses of social media. Overall, findings indicate very little use of social media by these business journalists. Results and implications for public relations practitioners are discussed in detail.  相似文献   
69.
Our understanding of the underlying demographic components of population change in new Hispanic destinations is limited. In this paper, we (1) compare Hispanic migration patterns in traditional settlement areas with new growth in emerging Hispanic destinations; (2) examine the role of immigration vis‐à‐vis domestic migration in spurring Hispanic population redistribution; and (3) document patterns of migrant selectivity, distinguishing between in‐migrants and non‐migrant Hispanics at both the origin and destination. We use several recent datasets, including the 1990 and 2000 Public Use Microdata Samples (which include new regional geocodes), and the 2005 and 2006 files of the American Community Survey. Our results document the widespread dispersion of the Hispanic population over the 1990–2006 period from established Hispanic gateways into new Hispanic areas and other parts of the country. Nearly one‐half of Hispanic net migration in new destinations comes from domestic gains. In contrast, both established and other Hispanic areas depend entirely on immigration, with each losing domestic migrants to high growth areas. Migrant flows also are highly differentiated by education, citizenship, and nativity. To fully understand the spatial diffusion of Hispanics requires a new appreciation of the complex interplay among immigration, internal domestic migration, and fertility.  相似文献   
70.
Sex‐based discrimination has resulted in severe demographic imbalances between males and females, culminating in a large number of “missing women” in several countries around the world. We provide new estimates and projections of the number of missing females and of the roles played by prenatal and postnatal factors in this imbalance. We estimate time series of the number of missing females, the number of excess female deaths, and the number of missing female births for the world and selected countries. Estimates are provided for 1970–2010 and projections are made from 2010 to 2050. We show that the estimates of these different indicators are consistent with one another and account for the dynamics of the population of missing females over time. We conclude that the number of missing females has steadily risen in the past decades, reaching 126 million in 2010, and the number is expected to peak at 150 million in 2035. Excess mortality was the dominant cause of missing females in the past, and this is expected to remain the case in future decades in spite of the recent rise of prenatal sex selection. The annual number of newly missing females reached 3.4 million in 2010 and is expected to remain above 3 million every year until 2050.  相似文献   
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