谷歌开卖电子书

谷歌计划今年夏季展开人们期待已久的进军电子书市场行动,该项目名为“谷歌版图书”。谷歌没有透露任何具体细节,只是表示将销售用互联网浏览器即可阅读的电子书。     

Tell Me a Story: A Review of Narrative Assessments for Preschoolers

The use of narrative assessments in mental health research with young children has increased significantly over the last 15 years. This article reviews 13 empirically validated narrative assessments for preschool populations. The reviewed instruments assess children’s attachment relationships, moral values, separation anxiety, pro-social behavior, object relations and depression, among other constructs. The authors present an analysis of each instrument including a discussion of its methodological rigor, and point to needed directions in the field. These narrative assessment instruments provide researchers and clinicians with insight into the internal worlds of young children, offering windows into a difficult-to-assess population.     

Political economy and the adoption of everyday environmental policies in the American states, 1997: an exploratory analysis

The political economy model has been widely and effectively used to explain and predict adoption rates of highly salient and/or controversial policies in the American states. However, use of this model to predict policy adoption in noncontroversial domains has been limited. This article tests the extent to which the model is successful in explaining the adoption of less-salient, everyday policies intended to improve environmental quality among the American states. The addition of conditional terms related to the model's political and bureaucratic components resulted in explaining 57% of the variance in commitment to everyday environmentalism among the American states. In sum, the number of everyday environmental policies adopted by state governments is a function of economic considerations, legislative accountability and professionalism, bureaucratic commitment, political culture and previous levels of policy adoption. Alternately—and unlike more controversial environmental policy domains—partisanship, ideology, party control of government and interest group forces do not have an impact on adoption of everyday environmental policies.     

Overdispersed poisson regression models for studies of air pollution and human health

This paper presents results from a simulation study motivated by a recent study of the relationships between ambient levels of air pollution and human health in the community of Prince George, British Columbia. The simulation study was designed to evaluate the performance of methods based on overdispersed Poisson regression models for the analysis of series of count data. Aspects addressed include estimation of the dispersion parameter, estimation of regression coefficients and their standard errors, and the performance of model selection tests. The effects of varying amounts of overdispersion and differing underlying variance structure on this performance were of particular interest. This study is related to work reported by Breslow (1990) although the context is quite different. Preliminary work led to the conclusion that estimation of the dispersion parameter should be based on Pearson's chi-square statistic rather than the Poisson deviance. Regression coefficients are well estimated, even in the présence of substantial overdispersion and when the model for the variance function is incorrectly specified. Despite potential greater variability, the empirical estimator of the covariance matrix is preferred because the model-based estimator is unreliable in general. When the model for the variance function is incorrect, model-based test statistics may perform poorly, in sharp contrast to empirical test statistics, which performed very well in this study.     

Leader–member exchange (LMX) in context: How LMX differentiation and LMX relational separation attenuate LMX's influence on OCB and turnover intention

Using the group engagement model, we hypothesize that two differentiated leadership constructs – LMX differentiation at the group level and a new construct, LMX relational separation, at the individual-within-group level – interact with LMX to affect follower citizenship behaviors (OCB) and turnover intentions. Data from 223 followers and their leaders situated across 60 workgroups demonstrate that the effects of individual perceived LMX quality are contingent upon a group's overall variability in LMX (i.e., LMX differentiation) and employees' similarity in terms of LMX with their coworkers (i.e., LMX relational separation). Specifically, the effects of high quality LMX relationships on OCB and turnover intentions are weaker when group LMX differentiation or employees' LMX relational separation is higher, rather than lower. Our findings contribute to a growing stream of multilevel LMX research incorporating climate effects and offer an alternative view of differentiated leadership in groups. Key implications for theory and practice are discussed.     

FACES IV and the Circumplex Model: validation study

Family Adaptability and Cohesion Evaluation Scale (FACES) IV was developed to tap the full continuum of the cohesion and flexibility dimensions from the Circumplex Model of Marital and Family Systems. Six scales were developed, with two balanced scales and four unbalanced scales designed to tap low and high cohesion (disengaged and enmeshed) and flexibility (rigid and chaotic). The six scales in FACES IV were found to be reliable and valid. High levels of concurrent, construct, and discriminant validity were found and new ratio scores measure the balanced and unbalanced level of cohesion and flexibility. A clinical example on the use of FACES IV scores to assess family dynamics, plan the treatment, and determine the impact of family therapy is provided.     

Family configuration and adolescent sexual attitudes and behavior

Several measures of family configuration, derived from the number, age, and sex of siblings and the number of parents, were related to adolescent sexual attitudes and behavior in a sample of 836 high school-aged teenagers from two Western states. Zero-order correlations showed that sexual intercourseexperience was less common among adolescents who lived with both parents and also among those who had younger siblings. Similarly, the zero-order correlations showed least permissiveattitudes among adolescents who had more siblings, especially younger siblings, and among those who lived with both parents. Controlling for adolescents' age, sex, race, religion, church attendance, and parents' educational attainment, however, essentially eliminated the relationships between family configuration variables and sexual attitudes and behavior. Only parents' marital structure, reflecting whether adolescents lived with both original parents or not, continued to be weakly related to adolescents' sexual attitudes and behvior.