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61.
Sowmya Rajan S. Philip Morgan Kathleen Mullan Harris David Guilkey Sarah R. Hayford Karen Benjamin Guzzo 《Population research and policy review》2017,36(6):903-928
Having an unintended birth is strongly associated with the likelihood of having later unintended births. We use detailed longitudinal data from the Add Health Study (N = 8300) to investigate whether a host of measured sociodemographic, personality, and psychosocial characteristics select women into this “trajectory” of unintended childbearing. While some measured characteristics and aspects of the unfolding life course are related to unintended childbearing, explicitly modeling these effects does not greatly attenuate the association of an unintended birth with a subsequent one. Next, we statistically control for unmeasured time-invariant covariates that affect all birth intervals, and again find that the association of an unintended birth with subsequent ones remains strong. This persistent, strong association may be the direct result of experiencing an earlier unintended birth. We propose several mechanisms that might explain this strong association. 相似文献
62.
Erectile dysfunction (ED) is one of the most common disorders in male and is often associated with other age-related comorbidities. The aging process affects the structural organization and function of penile erectile components such as smooth muscle cell and vascular architecture. These modifications affect penile hemodynamics by impairing cavernosal smooth muscle cell relaxation, reducing penile elasticity, compliance and promoting fibrosis. This review aims to identify the mechanisms of ED in the penile aging process in experimental and clinical data. It also highlights areas that are in need of more research. The search strategies yielded total records screened from PubMed. Clarification of the molecular mechanisms that accompanies corpus cavernosum aging and aging-associated ED will aid new perspectives in the development of novel mechanism-based therapeutic approaches. Age is not a limiting factor for ED medical management, and it is never too late to treat. Hypogonadism should be managed regardless of age, and synergistic effects have been found during testosterone (T) replacement therapy when used along with oral phosphodiesterase-5 (PDE-5) inhibitors. Therefore, the clinical management of ED related to aging can be done by therapeutic interventions that include PDE-5 inhibitors, and other pharmacological treatments. 相似文献
63.
Correlated data are commonly analyzed using models constructed using population-averaged generalized estimating equations (GEEs). The specification of a population-averaged GEE model includes selection of a structure describing the correlation of repeated measures. Accurate specification of this structure can improve efficiency, whereas the finite-sample estimation of nuisance correlation parameters can inflate the variances of regression parameter estimates. Therefore, correlation structure selection criteria should penalize, or account for, correlation parameter estimation. In this article, we compare recently proposed penalties in terms of their impacts on correlation structure selection and regression parameter estimation, and give practical considerations for data analysts. Supplementary materials for this article are available online. 相似文献
64.
It is well known that in finance variances and covariances of asset returns move together over time. Recently, much interest has been aroused by an approach involving the use of the realized covariance (RCOV) matrix constructed from high-frequency returns as the ex-post realization of the covariance matrix of low-frequency returns. For the analysis of dynamics of RCOV matrices, we propose the generalized conditional autoregressive Wishart (GCAW) model. Both the noncentrality matrix and scale matrix of the Wishart distribution are driven by the lagged values of RCOV matrices, and represent two different sources of dynamics, respectively. The GCAW is a generalization of the existing models, and accounts for symmetry and positive definiteness of RCOV matrices without imposing any parametric restriction. Some important properties such as conditional moments, unconditional moments, and stationarity are discussed. Empirical examples including sequences of daily RCOV matrices from the New York Stock Exchange illustrate that our model outperforms the existing models in terms of model fitting and forecasting. 相似文献
65.
The Diffusion of Tolerance: Birth Cohort Changes in the Effects of Education and Income on Political Tolerance 下载免费PDF全文
Political tolerance—the willingness to extend civil liberties to traditionally stigmatized groups—is pivotal to the functioning of democracy and the well‐being of members of stigmatized groups. Although political tolerance has traditionally been more common among American elites, we argue that as tolerance has increased, it has also diffused to less educated and less affluent segments of the population. The relative stability of political attitudes over the life course and the socialization of more recent birth cohorts in contexts of increased tolerance suggest that this diffusion of tolerance occurs across birth cohorts rather than time periods. Using age‐period‐cohort models and more than three and a half decades of repeated cross‐sectional survey data, we find persistent and robust across‐cohort declines in the importance of both income and higher education in determining levels of political tolerance. Declines in the effects of socioeconomic status are evident with tolerance toward all five out‐groups in the analysis—anti‐religionists, gays and lesbians, communists, militarists, and racists—but to varying degrees. These findings fit with a model of changes in public opinion, particularly views of civil and political rights, through processes of cultural diffusion and cohort replacement. 相似文献
66.
Adult social care services in the United Kingdom have undergone a period of transformation over recent years, characterised by a drive towards personalised care. Concurrently, social care budgets have been significantly reduced. This study aimed to explore the daily living experiences of adults with mild/moderate intellectual disabilities, who are at risk of no longer meeting eligibility criteria for statutory support. Focus group discussions, which included both people with intellectual disabilities and support workers, were analysed thematically. Two broad themes are presented: independence and agency; and social capital and well-being. While some participants echoed ideas central to the personalisation narrative, a number of contextual barriers to achieving greater independence and agency were discussed. Moreover, greater independence was not a desired goal for all participants. The findings highlight the potential mismatch between personalised social care, as delivered within significant budget constraints, and the needs of adults with intellectual disabilities. 相似文献
67.
This field study provides variables that can be used by practitioners as action levers and by future researchers as the basis for theoretical development. Conclusions from relevant literature and findings from interviews with interdisciplinary research management identified forty variables that were viewed as important to interdisciplinary research project success. After adjusting the data for reliability attenuation, these variables were further analyzed to identify the best prediction equation. The findings suggested that project age or the longevity of the project and open discussion of disagreements were the best predictors of performance. 相似文献
68.
This article uses a demographic approach and data from the Health and Retirement Survey, a nationally representative sample of the U.S. population, to investigate sex differences in the length of life lived with heart disease and after a heart attack for persons in the United States age 50 and older. On average, women live longer than men with heart disease. At age 50 women can expect to live 7.9 years and men 6.7 years with heart disease. The average woman experiences heart disease onset three years older and heart attacks 4.4 years older than men. 相似文献
69.
70.
Philip A. Cowan Carolyn Pape Cowan Marsha Kline Pruett Kyle Pruett Jessie J. Wong 《Journal of marriage and the family》2009,71(3):663-679
Few programs to enhance fathers' engagement with children have been systematically evaluated, especially for low‐income minority populations. In this study, 289 couples from primarily low‐income Mexican American and European American families were randomly assigned to one of three conditions and followed for 18 months: 16‐week groups for fathers, 16‐week groups for couples, or a 1‐time informational meeting. Compared with families in the low‐dose comparison condition, intervention families showed positive effects on fathers' engagement with their children, couple relationship quality, and children's problem behaviors. Participants in couples' groups showed more consistent, longer term positive effects than those in fathers‐only groups. Intervention effects were similar across family structures, income levels, and ethnicities. Implications of the results for current family policy debates are discussed. 相似文献