Small‐sphere distributions for directional data with application to medical imaging

We propose novel parametric concentric multi‐unimodal small‐subsphere families of densities for p ? 1 ≥ 2‐dimensional spherical data. Their parameters describe a common axis for K small hypersubspheres, an array of K directional modes, one mode for each subsphere, and K pairs of concentrations parameters, each pair governing horizontal (within the subsphere) and vertical (orthogonal to the subsphere) concentrations. We introduce two kinds of distributions. In its one‐subsphere version, the first kind coincides with a special case of the Fisher–Bingham distribution, and the second kind is a novel adaption that models independent horizontal and vertical variations. In its multisubsphere version, the second kind allows for a correlation of horizontal variation over different subspheres. In medical imaging, the situation of p ? 1 = 2 occurs precisely in modeling the variation of a skeletally represented organ shape due to rotation, twisting, and bending. For both kinds, we provide new computationally feasible algorithms for simulation and estimation and propose several tests. To the best knowledge of the authors, our proposed models are the first to treat the variation of directional data along several concentric small hypersubspheres, concentrated near modes on each subsphere, let alone horizontal dependence. Using several simulations, we show that our methods are more powerful than a recent nonparametric method and ad hoc methods. Using data from medical imaging, we demonstrate the advantage of our method and infer on the dominating axis of rotation of the human knee joint at different walking phases.     

Noninformative priors for the between-group variance in the unbalanced one-way random effects model with heterogeneous error variances

For the unbalanced one-way random effects model with heterogeneous error variances, we propose the non-informative priors for the between-group variance and develop the first- and second-order matching priors. It turns out that the second-order matching priors do not exist and the reference prior and Jeffreys prior do not satisfy a first-order matching criterion. We also show that the first-order matching prior meets the frequentist target coverage probabilities much better than the Jeffreys prior and reference prior through simulation study, and the Bayesian credible intervals based on the matching prior and reference prior give shorter intervals than the existing confidence intervals by examples.     

Loneliness and the use of social media to follow celebrities: A moderating role of social presence

Because social media provide users with the possibility of an easy way to communicate with celebrities in society, it has become a more common practice to follow celebrities through social media. However, there exists few studies that examine how people’s individual characteristics are related to their celebrity-following behavior. In this regard, the current study examines whether celebrity followers’ loneliness is associated with the following behavior of their favorite celebrity. Data were collected through an online survey (N = 210). Primary findings suggest that celebrity followers’ loneliness is positively related to frequent visits of their favorite celebrity’s social media, greater social-interpersonal motive for following the celebrity, and greater enjoyment of learning about personal life stories of the celebrity. Social presence is found to be a significant moderator that can intensify more favorable parasocial relationship perceptions with the celebrity.     

Stakeholder perceptions of contextual factors related to PBIS implementation in high need schools

Positive behavior intervention and supports (PBIS) is a thoroughly researched three-tiered framework for preventing and treating challenging behavior in schools. While more than 20 years of research contribute to the literature base, less is known about PBIS implementation in high-needs school settings, particularly those that serve students predominantly from low-income families and majority minority student populations across urban and rural districts. This study investigated the critical contextual factors of PBIS implementation from the stakeholder perspective. Specifically, we surveyed 161 participants including teachers, school staff members, and administrators who were PBIS team members and had received technical assistance in PBIS implementation. The completed surveys were analyzed with participants and their schools coded for district type, Title I funding, and position in order to determine how the perceptions of issues such as buy-in, administrator support, PBIS in secondary school settings, and poverty affect PBIS implementation and team needs. The factor analysis and resulting structure along with statistically significant results for each factor are presented along with implications.     

Apathy and Antipathy: Media Coverage of Restrictive Immigration Legislation and the Maintenance of Symbolic Boundaries

Although the government no longer explicitly establishes boundaries of whiteness, it continues to play a central role in shaping symbolic boundaries between immigrants and nonimmigrants through immigration lawmaking. However, the salience of these boundaries may depend on how the media disseminate them to the public. In this study, we investigate media framing of immigration lawmaking using an original data set of news coverage of six of the most widely recognized exclusionary immigration bills and laws at different levels of government. Two patterns emerged from an iterative frame analysis. First, in their coverage of frames critical of these bills and laws, outlets devoted more attention to the effects of exclusionary legislation for nonimmigrants. Second, in their coverage of frames supportive of the restrictive legislation, outlets provided more space to those who openly associated immigrants with criminality and terrorism. Regardless of outlets’ seemingly neutral stance toward restrictive legislation, their disparate coverage of exclusionary lawmaking demonstrates apathy and antipathy toward immigrants, which has repercussions for the maintenance of inequality.     

Using social support levels to predict sexual identity development among college students who identify as a sexual minority

This study examined the impact of five domains of social support (a campus group for individuals who identify as a sexual minority, family, friends, significant others, and faith communities) on eight aspects of sexual minority identity development (identity uncertainty, internalized homonegativity, identity affirmation, acceptance concerns, identity superiority, concealment motivation, identity centrality, and difficulty in the identity development process). Support from a sexuality-specific campus group was the strongest predictor, followed by support from family members. Supports from friends and significant others had no significant impact on any aspect of sexual minority identity development, while faith community support was not correlated with identity development. Identifying as lesbian, bisexual, or as another sexual minority compared to identifying as gay also impacted sexual minority identity development.     

Internet literacy and digital natives’ civic engagement: Internet skill literacy or Internet information literacy?

This study aims to show the role of Internet literacy in empowering digital natives’ civic engagement. Using a survey of 10th graders, we analyzed the effects of digital media use and Internet literacy on adolescents’ political and social interest, participation, and efficacy, controlling for their home and school environments. In doing so, we try to highlight the following points. First, we emphasize that there are two separate dimensions of Internet literacy: Internet skill literacy and Internet information literacy. Second, we adopt a broader concept of civic engagement reflecting the changing youth practices observed in the contemporary media environment. The study empirically found that Internet information literacy, not Internet skill literacy, is intricately related to adolescents’ civic engagement. It was also shown that adolescents’ Internet use contributed only to new and alternative forms of participation. Overall, the findings show that an adolescent who can critically understand and effectively evaluate online information is more likely to become an active civic participant than one who lacks such skills. The study concludes with a few policy suggestions.     

Integrative Cycle Scheduling Approach for a Capacitated Flexible Assembly System*

This study revisits the traditional single stage, multi-item, capacitated lot-sizing problem (CLSP) with a new integrative focus on problem structuring. Unlike past research, we develop integrative cycle scheduling approaches which simultaneously address lot-sizing, capacity, and sequencing issues. Our purposes are to (1) explore the effect of sequencing on inventory levels, (2) examine the problem of infeasibility in the economic lot scheduling problem (ELSP), and (3) provide a simple methodology of generating low-cost cycle schedules in an environment with discrete shipping, dynamic demands, limited capacity, zero setup cost, and sequence-independent setup times. Our procedures are compared to benchmark cycle scheduling approaches in terms of both inventory cost and computation time under different demand scenarios, using the operating data from a flexible assembly system (FAS) at the Ford Motor Company's Sandusky, Ohio plant.     

Issue Information

In 2017, the number of applications for care orders in England and Wales was the highest ever recorded at 14,207. This is a significant factor, contributing to the rise in the number of children who are looked after, which is at the highest level since 1985. The authors reflect on the recently published Care Crisis Review 2018, a sector‐led review, which examines the reasons for the rise in care proceedings and the number of children in care. The review sought to identify changes to policy and practice within local authorities and the family justice system, in an attempt to divert cases away from the family courts and to reduce the number of children in care, where it is safe to do so. Whilst the legislative framework is largely effective and the system generally works well, there is insufficient funding and resources to meet the needs of children and their families when they seek help, regardless of whether this is at an early stage or when they are in crisis and most in need of care and protection.