An Evaluation of Risk Estimation Procedures for Mixtures of Carcinogens

The estimation of health risks from exposure to a mixture of chemical carcinogens is generally based on the combination of information from several available single compound studies. The current practice of directly summing the upper bound risk estimates of individual carcinogenic components as an upper bound on the total risk of a mixture is known to be generally too conservative. Gaylor and Chen (1996, Risk Analysis) proposed a simple procedure to compute an upper bound on the total risk using only the upper confidence limits and central risk estimates of individual carcinogens. The Gaylor-Chen procedure was derived based on an underlying assumption of the normality for the distributions of individual risk estimates. In this paper we evaluated the Gaylor-Chen approach in terms of the coverage probability. The performance of the Gaylor-Chen approach in terms the coverages of the upper confidence limits on the true risks of individual carcinogens. In general, if the coverage probabilities for the individual carcinogens are all approximately equal to the nominal level, then the Gaylor-Chen approach should perform well. However, the Gaylor-Chen approach can be conservative or anti-conservative if some or all individual upper confidence limit estimates are conservative or anti-conservative.     

Satisfaction Ratings of QOLPAV: Psychometric Properties Based on the Graded Response Model

A scale measuring quality of life (QOL) is important in adolescent research. Using the graded response model (GRM), this study evaluates the psychometric properties of the satisfaction ratings of the Quality of Life Profile Adolescent Version (QOLPAV). Data for 1,392 adolescents were used to check IRT assumptions such as unidimensionality and local item dependence (LID). The goodness of fit of the GRM to the data and the item characteristic curves were evaluated. The reliability and validity analyses included item/test information, Cronbach’s α, and convergent and discriminant validity. Differential item functioning (DIF) procedures were also performed to detect item bias. The results provide evidence that the items sufficiently measured one single dimension. Few pairs of questions were flagged as LID due to content or wording similarity. Five items did not fit the GRM, and 4 were low in item discrimination. The findings also suggest that the assessment had appropriate reliability and validity. The DIF impact on the assessment score was considered minor. Because QOLPAV includes a respondent’s perceived importance of various life aspects, a short form that only considers important life aspects in the overall QOL estimation for each respondent becomes feasible within the framework of IRT. Future studies focusing on the development of a QOL overall index using the items from QOLPAV are recommended.     

The Effects of Family-Friendly Policies and Workplace Social Support on Parenting Stress in Employed Mothers Working Nonstandard Hours

This study examines whether family-friendly policies (childcare leave, on-site childcare, and flexible working hours) and workplace social support (supervisor and coworker support) in South Korea are directly related to parenting stress among employed mothers with nonstandard work schedules. In addition, this study investigates the moderating role of family-supportive organization perceptions in the aforesaid associations. Data were collected from 223 employed mothers who have nonstandard work schedules with at least one or more children under the age of six. Results show that on-site childcare, flexible working hours, and supervisor support are negatively associated with parenting stress, whereas childcare leave is positively associated with parenting stress. Employed mothers with high family-supportive organization perceptions report low levels of parenting stress when they received high levels of supervisor support or did not take childcare leave. Additionally, employed mothers with low family-supportive organization perceptions report high levels of parenting stress when they did not use on-site childcare. Consequently, our findings indicate that employed mothers’ greater family-supportive organization perceptions are key factor reducing their parenting stress when they are limited to use family-friendly policies. Implications are discussed in terms of the importance of work-family intervention to the work-family balance among mothers working nonstandard hours.     

The Aftercare Support Program: An Emerging Group Intervention for Transition-Aged Youth

The unique challenges faced by transition-aged youth have received considerable attention in the literature, but few developments for aftercare support interventions have followed. The Aftercare Support Program (ASP) is a group-based intervention designed for such youth. ASP was developed as a zero budget, low-intensity intervention delivered by volunteers from a local college/university and youth-serving agencies to encourage transition-aged youth to pursue postsecondary education and vocational training by utilizing existing community resources and services. The underlying theoretical concepts are derived from solution-focused brief therapy and a strengths-perspective in social work. Case vignettes, including feedback from participants and lessons learned are offered, along with implications for the ASP model and other aftercare support models for transition-aged youth at a time when public and private funds for such programs are limited.     

Urban Governance Reform Index: An Alignment of Traditional Reform and Public Choice Propositions

The persistent debate on the consolidation versus fragmentation model of government is a result of a dualist conceptualization of governance reform by two competing theories—public choice and traditional reform. Both argue for reform, but their definitions of reform are diametrically opposed and there is no appropriate instrument to measure government reform. We propose an alignment of the traditional reform and public choice traditions and an instrument to measure governance reform by an index comprised of 1) form of government, 2) home-rule status, 3) methods of election, 4) number of elected officials, and 5) number of jurisdictions. The alignment of the two theoretical camps is supported by the selection of the five reform components and their particular operationalizations.     

Public's expectation about an organization's stance in crisis communication based on perceived leadership and perceived severity of threats

Considering the importance of general public support of an organization during a crisis, this study examined how perceived leadership style influences public expectation about an organization's stance in crisis and the relationship between perceived severity of threat and the expected stance of the organization based on leadership perception. The results of the study strongly supported main effects of leadership on public estimation about an organization's stance. Managerial implications were discussed.     

Chinese Relationalism: Theoretical Construction and Methodological Considerations

The goal of this article is attempting to establish a research tradition of Chinese relationalism on the methodological grounds of constructive realism. Two of Ho's (1993, 1998a) key concepts, person-in-relations and persons-in-relation, are carefully examined and reinterpreted. Three of my theoretical models, namely, my Face and Favor model (Hwang, 1987), Confucian ethics for ordinary people (Hwang, 1995), and a conflict resolution model (Hwang, 1997-8), are conceived of as microworlds for illustrating an account of person-in relations in Chinese culture. The manifestation of Confucian ethics for ordinary people in one's lifeworld results in the phenomenology of persons-in-relations as depicted by Fei's (1948) differential order or Hsu's (1971a) psychosociogram. Applying constructive realism to my models and using the result as a framework for studying Chinese social behavior constitutes Chinese relationalism.     

The journey effect: how travel affects the experiences of mental health in-patient service-users and their families

The qualitative study presented in this paper explored the perspectives of service-users, family members and staff about the impact of travel issues on the lives of mental health in-patients and carers. This topic was chosen because it was prioritised by members of Xplore, a service-user and carer research group, and has received little research attention. Travel problems were a significant issue for many service-users and carers, bound-up with mental health issues and the recovery experience. Travel facilitation through the funding of taxis and the provision of guides was appreciated. A few service-users and carers positively valued distancing from their previous home environment. The meaning of travel issues could only be understood in the context of individuals’ wider lives and relationships. The significance of the findings is discussed in relation to the social model of disability.     

Improved confidence estimators for Fieller's confidence sets

Fieller's confidence set C_F for ratios of location parameters, although of great importance in practice, is often cited as an example to criticize frequentist theory. The reason is that the set can consist of the whole parameter space and yet the confidence is γ = 1 – α in any case. In this paper, we study the problem of constructing data-dependent estimators better than γ₊, A reasonable estimator appears to be γ₊, which is one if C_F is the whole parameter space and γ otherwise. By using an estimated confidence approach and a squared-error loss, it is shown that γ₊ dominates γ. The risk improvement of γ₊ over γ can be sizable. Also, by numerically comparing γ₊ with a generalized Bayes estimator γ_L, which is shown to be admissible when one or two ratios are concerned, it is shown that γ₊ is nearly admissible. We also conclude that the common practice of reporting 1 – α only when C_F is not the whole parameter space is nearly admissible.