Simulating space-time random fields with nonseparable Gneiting-type covariance functions

Statistics and Computing - Two algorithms are proposed to simulate space-time Gaussian random fields with a covariance function belonging to an extended Gneiting class, the definition of which...     

Inference in Semi‐Parametric Dynamic Models for Repeated Count Data

This paper deals with a longitudinal semi‐parametric regression model in a generalised linear model setup for repeated count data collected from a large number of independent individuals. To accommodate the longitudinal correlations, we consider a dynamic model for repeated counts which has decaying auto‐correlations as the time lag increases between the repeated responses. The semi‐parametric regression function involved in the model contains a specified regression function in some suitable time‐dependent covariates and a non‐parametric function in some other time‐dependent covariates. As far as the inference is concerned, because the non‐parametric function is of secondary interest, we estimate this function consistently using the independence assumption‐based well‐known quasi‐likelihood approach. Next, the proposed longitudinal correlation structure and the estimate of the non‐parametric function are used to develop a semi‐parametric generalised quasi‐likelihood approach for consistent and efficient estimation of the regression effects in the parametric regression function. The finite sample performance of the proposed estimation approach is examined through an intensive simulation study based on both large and small samples. Both balanced and unbalanced cluster sizes are incorporated in the simulation study. The asymptotic performances of the estimators are given. The estimation methodology is illustrated by reanalysing the well‐known health care utilisation data consisting of counts of yearly visits to a physician by 180 individuals for four years and several important primary and secondary covariates.     

On the Joint Estimation of Heterogeneous Technologies,Technical, and Allocative Inefficiency

In this article, we provide a semiparametric approach to the joint measurement of technical and allocative inefficiency in a way that the internal consistency of the specification of allocative errors in the objective function (e.g., cost function) and the derivative equations (e.g., share or input demand functions) is assured. We start from the Cobb–Douglas production and shadow cost system. We show that the shadow cost system has a closed-form likelihood function contrary to what was previously thought. In turn, we use the method of local maximum likelihood applied to a system of equations to obtain firm-specific parameter estimates (which reveal heterogeneity in production) as well as measures of technical and allocative inefficiency and its cost. We illustrate its practical application using data on U.S. electric utilities.     

Political Expertise and the Use of Ideology: Moderating Effects of Evaluative Motivation

Much research suggests that political experts are more likelyto structure attitudes toward different issues in an ideologicallyconsistent fashion. Based on recent studies of motivationalinfluences on social cognition, we hypothesize that only expertswith a high need to evaluate—a strong motivation to establishevaluations of social objects—may "apply" ideology toa variety of issues. Data from the 1998 NES Pilot and 2000 NESare used to examine this hypothesis. While experts do show moreideological constraint, this relationship appears to be limitedto individuals with a high need to evaluate. Additional analysesindicated that this interactive effect extended to other indicesof the use of ideology as well.     

Birthfamilies as permanency resources for children in long-term foster care

Provisions of the Adoption and Safe Families Act of 1997 mandated shorter time frames for making permanency decisions and facilitating adoption. Yet for many children, foster care continued to be a significant portion of their life experiences. This project explored the potential permanency option of birthfamilies and extended kin for children who languished in foster care while being free for adoption. Eighteen children achieved permanent placement with their birthfamilies. In addition, staff found that although many families could not provide permanent placements, they could offer appropriate relationships with the children. This project team recommends viewing family relationships as an integral component where placement is one option on a continuum that includes letters, phone calls, and visits.     

Well balanced: 8 steps to wellness for adults with mental illness and diabetes

Serious mental illness places a tremendous burden on clients, their families, and behavioral and medical health care providers. The co-occurrence of diabetes with mental illness may further compromise daily functioning. Psychiatric nurses can make a significant difference in improving the health and medical outcomes of this client population. A partnership was developed between the University of Rochester School of Nursing and the Western New York Care Coordination Program to evaluate a novel nursing model for adults with both serious mental illness and diabetes mellitus. The Well Balanced program incorporated health promotion, disease management, nursing care management, and evidence-based practice guidelines into 8 Steps to Wellness for a community-based mental health population. During a 16-visit intervention period, psychiatric nurses interacted with 74 clients. As a result of the program, clients experienced improvements in health risk status and in their hemoglobin A1C and reported high satisfaction with the Well Balanced program.     

Fractured relationships and the potential for abuse of older men

Elderly men are an understudied population in the area of abuse and neglect. The typical elder abuse or neglect victim is described as a frail woman. The National Elder Abuse Incidence Study shows men to be victims as well and at higher risk than women for abandonment, the most extreme form of neglect. A qualitative study of older widowed men did not specifically explore issues of abuse and neglect, but found several of the men experiencing alienation from one or more of their adult children. This paper explores the dynamics of these "fractured relationships" and finds several patterns that may increase an older man's risk of being neglected when his needs for support increase. Many men are not functioning in a kinkeeper role and are not attempting to repair fractured relationships. Minimizing their own feelings may prevent men from understanding the extent of alienation felt by an adult child.     

Prevalence and characteristics of sexual violence victimization among U.S. adults, 2001-2003

This article provides the most recent U.S. prevalence estimates of forced sex and unwanted sexual activity. Results of a national telephone survey conducted in 2001-2003 indicate that 1 in 59 U.S. adults (2.7 million women and 978,000 men) experienced unwanted sexual activity in the 12 months preceding the survey and that 1 in 15 U.S. adults (11.7 million women and 2.1 million men) have been forced to have sex during their lifetime. There were 60.4% of females and 69.2% of males who were 17 years old or younger at the time the first forced sex occurred. This study provides an update to the National Violence Against Women Survey with more recent national data. Findings suggest that victimization rates have remained consistent since the 1990s. These findings suggest that a continued effort toward primary prevention of sexual violence, particularly rape of children and adolescents, is needed.     

Environmental changes to increase physical activity: perceptions of older urban ethnic-minority women

Despite the numerous benefits of physical activity, older adults continue to be more sedentary than their younger counterparts, and sedentary behavior is more prevalent among older racial and ethnic minorities than among Whites. This study used the nominal group technique (NGT) to examine participants' perceptions of what neighborhood environmental changes would encourage greater physical activity for older African American and Hispanic women. Participants age 50-75 years were recruited from 2 urban community health clinics. Nine NGT sessions (45 participants) were conducted. The women were asked what changes in their neighborhood environment would encourage them to become more physically active. Responses to the research question were tabulated, and qualitative analysis was used to identify themes and categories. Major categories were physical environment changes, safety, and activities/social support. Although the physical environment received the greatest number of points, concerns for personal safety cut across categories. Participants indicated the need for more facilities in which to be active.     

Is Work-Family Policy Use Related to the Gendered Division of Housework?

Researchers have proposed that work-family policy use may either reinforce or challenge the existing gendered division of labor within couples, but results from prior studies have been inconclusive. Using data from a regional survey of work and family life, we extend this research by focusing on how housework is divided within couples and by differentiating between traditionally female- and male- typed housework tasks. Results show that among dual-earning women, policy use is not related to share of female- or male-typed tasks. Among dual-earning men, policy use is positively related to share of female-typed tasks and negatively related to share of male-typed tasks. These findings suggest that work-family policy use does not reinforce the gendered division of housework.