A new aging concept derived from the increasing convex ordering

In this paper, a comparison between the life distribution of a new unit with that of a used unit in the increasing convex order is made leading to a new class of life distributions which we call “new better than used in convex ordering of second order”. This class includes as subclasses the NBU and the NBUC and is a subclass of the NBUCA class. Preservation properties under convolution, random maxima, mixing and formation of coherent structures are established. Stochastic comparisons of the excess lifetime when the inter-arrival times belong to the NBUC(2) class are developed. Some applications of Poisson shock models and a test of exponentiality against NBUC(2) alternative are presented.     

Special issue dedicated to Odd O. Aalen

Lifetime Data Analysis -     

A reflected feature space for CART

We present an algorithm for learning oblique decision trees, called HHCART(G). Our decision tree combines learning concepts from two classification trees, HHCART and Geometric Decision Tree (GDT). HHCART(G) is a simplified HHCART algorithm that uses linear structure in the training examples, captured by a modified GDT angle bisector, to define splitting directions. At each node, we reflect the training examples with respect to the modified angle bisector to align this linear structure with the coordinate axes. Searching axis parallel splits in this reflected feature space provides an efficient and effective way of finding oblique splits in the original feature space. Our method is much simpler than HHCART because it only considers one reflected feature space for node splitting. HHCART considers multiple reflected feature spaces for node splitting making it more computationally intensive to build. Experimental results show that HHCART(G) is an effective classifier, producing compact trees with similar or better results than several other decision trees, including GDT and HHCART trees.     

Risking safety and rights: online sex work,crimes and ‘blended safety repertoires’

It has been well established that those working in the sex industry are at various risks of violence and crime depending on where they sell sex and the environments in which they work. What sociological research has failed to address is how crime and safety have been affected by the dynamic changing nature of sex work given the dominance of the internet and digital technologies, including the development of new markets such as webcamming. This paper reports the most comprehensive findings on the internet‐based sex market in the UK demonstrating types of crimes experienced by internet‐based sex workers and the strategies of risk management that sex workers adopt, building on our article in the British Journal of Sociology in 2007. We present the concept of ‘blended safety repertoires’ to explain how sex workers, particularly independent escorts, are using a range of traditional techniques alongside digitally enabled strategies to keep themselves safe. We contribute a deeper understanding of why sex workers who work indoors rarely report crimes to the police, reflecting the dilemmas experienced. Our findings highlight how legal and policy changes which seek to ban online adult services advertising and sex work related content within online spaces would have direct impact on the safety strategies online sex workers employ and would further undermine their safety. These findings occur in a context where aspects of sex work are quasi‐criminalized through the brothel keeping legislation. We conclude that the legal and policy failure to recognize sex work as a form of employment, contributes to the stigmatization of sex work and prevents individuals working together. Current UK policy disallows a framework for employment laws and health and safety standards to regulate sex work, leaving sex workers in the shadow economy, their safety at risk in a quasi‐legal system. In light of the strong evidence that the internet makes sex work safer, we argue that decriminalisation as a rights based model of regulation is most appropriate.     

White Ethnic Diversity in Small Town Iowa: A Multilevel Analysis of Community Attachment

Community attachment is the feeling of being connected to community life. Within the community attachment literature, two classic approaches frame scholars’ understanding of this important dimension of community life: the linear development and systemic models. Our empirical models emphasize different factors for community attachment, including population size, density, and heterogeneity for the linear development model and age, length of residence, and social status for the systemic model. Surprisingly, heterogeneity has been omitted from analyses of the linear development model throughout the literature since its introduction, a shortcoming our study addresses. Though heterogeneity can be conceptualized in a number of ways, a large—and growing—body of literature focuses on the effects of race and ethnicity for communities. Here, we focus on a particular type of ethnic heterogeneity—European ancestry—and reincorporate this essential dimension of communities back into the linear development model of community attachment. Using data from the 2004 wave of the Iowa Community Survey and multilevel modeling techniques, we explore how white ethnic diversity matters for community life. We conclude with a discussion of the implications of our study, including potential avenues for future research focusing on other ethnicities that are often subsumed under broader racial and panethnic labels.     

Socioeconomic Resource Environments in Biological and Alternative Family Care and Children's Cognitive Performance*

We examined social and economic resources in the environments of children involved with child protective services and their associations with children's cognitive performance. We used a national dataset of child protection investigations (children aged 6–16 at Wave 1). Using latent class analysis, we constructed profiles of the financial resources, parental education and employment, and family structure and size. We then examined within‐ and across‐time associations between resource environment profiles and children's math and reading scores and tested whether associations differed by family care type. Our latent class analysis identified four distinct family resource environments: educated middle class, single earner, large working class, and severely disadvantaged. Family resource environment profiles predicted current cognitive performance and changes in performance over time, but associations were more consistent for children in biological family care. Children who remain in home following maltreatment allegations may benefit from services that target social as well as economic resources.     

The Role of Self-Conscious Emotions in the Sexual Health of Gay and Bisexual Men: Psychometric Properties and Theoretical Validation of the Sexual Shame and Pride Scale

Researchers have theorized about the role of sexual shame as a mechanism through which sexual minority stress manifests into mental health difficulties, such as sexual compulsivity for gay and bisexual men (GBM), and about the resilience-promoting effects of sexual pride. However, no validated measures to date have directly tapped into these constructs rather than using proxies for them, such as internalized homonegativity. We developed the Sexual Shame and Pride Scale (SSPS) and conducted a psychometric evaluation of it using a sample of 260 highly sexually active GBM. The scale had the expected structure in factor analysis and showed evidence of internal consistency and test–retest reliability. Correlational analyses demonstrated the convergent validity of sexual shame and sexual pride with relevant constructs. Regression analyses demonstrated the predictive validity of sexual shame in relation to sexual compulsivity, accounting for unique variability even after adjusting for previously demonstrated etiological factors, and the predictive validity of both shame and pride, which interacted to consistently predict four sexual behavior outcomes. Findings suggest the SSPS is a psychometrically valid and reliable measure that may be useful in future empirical work and highlight preliminary evidence for the role of these constructs in the sexual health of GBM.     

Trajectories of Limitations with Activities of Daily Living Among Older Adults of Mexican Descent: The Role of Widowhood

Using seven waves of data from the Hispanic Established Population for the Epidemiologic Study of the Elderly (1993–2011), this study applies multiphase growth models to examine changes in limitations with activities of daily living (ADL) across widowhood experience among 385 older adults of Mexican descent. This study also investigates the implications of demographic characteristics, health, socioeconomic status, living arrangements, and social involvement. ADL limitations increased pre-widowhood, were at higher levels immediately before and especially during the transition to widowhood, and increased at a steeper rate post-widowhood. Age and partially depressive symptoms accounted for these trends in ADL limitations pre-widowhood and to a lesser extent during the transition to widowhood and post-widowhood. Older age, being female, chronic conditions, financial strain, lower educational attainment, coresidence with children and others, and less frequent church attendance were risk factors for higher levels of and greater increases in these functional limitations throughout widowhood experience.     

Trajectories of Interracial Heterosexual Couples: A Longitudinal Analysis of Relationship Quality and Separation

Minimal research has examined interracial couples’ relationship satisfaction and dissolution patterns over time. Using dyadic data across 8 years, we examined potential differences in relationship quality trajectories through latent growth curve modeling with 1,336 couples as well as differential risks for relationship dissolution through logistic regression between same‐race and interracial relationships using a different subset of 2,370 couples. Results indicated that women in interracial relationships were significantly lower in initial relationship quality than women in same‐race relationships. Further, interracial couples of Black‐Hispanic partnerings were twice as likely to separate across 8 years than same‐race couples. These results suggest that despite interracial relationships not substantively differing from same‐race couples in trajectories of relationship quality, specific Black‐Hispanic interracial couples are at a higher risk of eventual separation.