A nonparametric hypothesis test for heteroscedasticity

In this paper, a hypothesis test for heteroscedasticity is proposed in a nonparametric regression model. The test statistic, which uses the residuals from a nonparametric fit of the mean function, is based on an adaptation of the well-known Levene's test. Using the recent theory for analysis of variance when the number of factor levels goes to infinity, the asymptotic distribution of the test statistic is established under the null hypothesis of homocedasticity and under local alternatives. Simulations suggest that the proposed test performs well in several situations, especially when the variance is a nonlinear function of the predictor.     

Effects of a ball-backrest chair on the muscles associated with upper crossed syndrome when working at a VDT

This study examined the effect of a ball-backrest chair on the weakness and tightness of muscles associated with upper crossed syndrome when working at a visual display terminal (VDT). The surface electromyography (EMG) was recorded from the serratus anterior, middle trapezius, and upper trapezius muscles of 20 adults as they performed VDT work, which are known as the weakened and tightened muscles of upper crossed syndrome. The recorded signals were averaged and normalized to the mean amplitude of the EMG signal obtained during submaximal reference voluntary contractions. The significance of differences between the use of a general-purpose backrest and a ball backrest was tested by paired t-test, with the significance cutoff set at alpha=0.05. The activities of the serratus anterior and middle trapezius muscles increased and that of the upper trapezius muscle decreased when sitting in a ball-backrest chair compared to when sitting in a chair with a general-purpose backrest (p<0.05). These results indicate that the use of a ball-backrest chair reduces the risk of patients with upper crossed syndrome developing muscles soreness or injury related to overuse when working at a VDT.     

Urge to Gamble in Problem Gamblers Exposed to a Casino Environment

Cue-reactivity has received increased attention in addiction research, though not for gambling in particular. We examined cue reactivity in 18 problem gamblers by accompanying them to a gaming casino and measuring their subjective urge to gamble over a 1-h period. Half of the sample was additionally exposed to a gambling-specific negative mood induction (NMI) manipulation via guided imagery. Overall, about two-thirds of the sample reported moderate to high-gambling urges during the casino exposure. Additionally, the NMI reduced cue-reactivity. Finally, gambling urges in both groups decreased over the course of the exposure sessions. These findings suggest that a majority of problem gamblers experience the urge to gamble when exposed to gambling cues and that the intensity of these urges decrease with time, especially in the presence of a gambling-relevant NMI. Cue exposure should be studied further as a potential tool in the treatment of problem gambling.     

The life-course origins of mastery among older people

In this article, we aim to identify the sources of mastery--the understanding that individuals hold about their ability to control the circumstances of their lives. The sample for our inquiry was drawn from the Medicare beneficiary files of people 65 and older living in Washington, DC, and two adjoining Maryland counties. We find that past circumstances, particularly those reflecting status attainment and early exposure to intractable hardships, converge with stressors experienced in late life to influence elders' level of mastery. The impact of past conditions, however, does not necessarily directly affect the current mastery of older people. Instead, the effect of prior experiences on current mastery is mediated by what we refer to as life-course mastery: one's belief that one has directed and managed the trajectories that connect one's past to the present. Our analyses show that life-course mastery largely serves as the mediating channel through which individuals connect their past to their present.     

How Are Money Worries Affecting Middle-Aged,Young-Old,and Old–Old People’s Perceived Couple Relationship?

While the association between financial strain and couple interaction has been well-established in the literature on economic stress, little research has investigated the association among middle-aged and older populations. The present study examined the relationships between financial strain and couple functioning of middle-aged, young-old, and old–old people using the 2010 Health and Retirement Study. Findings show that subjective financial strain was positively associated with partner undermining and negatively with partner support, controlling for the effects of objective financial situations among middle-aged, young-old, and old–old couples. There were gender and age differences in the interaction effects of financial strain and financial control on couple functioning. For middle-aged men, financial control may have different associations with couple behaviors depending on the level of financial strain. When the level of financial strain is high, the positive effect of financial control disappears and the effect changes even in a negative way. Findings provide suggestions for practitioners and researchers.     

Noninformative priors for linear combinations of normal means with unequal variances

For normal populations with unequal variances, we develop matching priors and reference priors for a linear combination of the means. Here, we find three second-order matching priors: a highest posterior density (HPD) matching prior, a cumulative distribution function (CDF) matching prior, and a likelihood ratio (LR) matching prior. Furthermore, we show that the reference priors are all first-order matching priors, but that they do not satisfy the second-order matching criterion that establishes the symmetry and the unimodality of the posterior under the developed priors. The results of a simulation indicate that the second-order matching prior outperforms the reference priors in terms of matching the target coverage probabilities, in a frequentist sense. Finally, we compare the Bayesian credible intervals based on the developed priors with the confidence intervals derived from real data.     

Challenges in Meeting the Mental Health Needs of Urban Asian American Adolescents: Service Providers’ Perspectives

Although Asian American youth are often viewed as the model minority group who are doing well, research with youths, parents, and school personnel have documented significant unmet mental health needs among this population. However, little is known about the perspectives of service providers who work with Asian American youth in afterschool and mental health care settings with respect to what they perceive as challenges meeting the psychosocial needs of the population. The current exploratory study used Consensual Qualitative Research to analyze in-depth interviews with mental health providers, educators, and advocates working with Asian American youths in a multiethnic large urban environment. Results found that service providers were attuned to the multiple needs of the community but also spoke of challenges in meeting basic and psychological needs due to difficult family dynamics, structural stressors (e.g., economic and legal), and societal stigma and discrimination. We draw implications for providing more integrated services across different levels of urban Asian American adolescents’ ecological system to better meet the psychosocial challenges facing this population.     

Exploring Adoption-Specific Curricula in Undergraduate and Graduate Degree Programs

The systemic impact of adoption suggests the need to explore adoption-specific curricula in baccalaureate and graduate degree programs. Using a convenience sample, the present exploratory study collected data in two phases. Phase one included email requests for adoption syllabi to professional email lists and to identified faculty with adoption research and practice expertise. In phase two, 22 faculty members who responded by emailing syllabi were invited to participate in an online survey. Results only begin to unveil what we know about adoption-specific curricula in higher education. Suggestions for future research are discussed.