Improved bridge constructs for stochastic differential equations

We consider the task of generating discrete-time realisations of a nonlinear multivariate diffusion process satisfying an Itô stochastic differential equation conditional on an observation taken at a fixed future time-point. Such realisations are typically termed diffusion bridges. Since, in general, no closed form expression exists for the transition densities of the process of interest, a widely adopted solution works with the Euler–Maruyama approximation, by replacing the intractable transition densities with Gaussian approximations. However, the density of the conditioned discrete-time process remains intractable, necessitating the use of computationally intensive methods such as Markov chain Monte Carlo. Designing an efficient proposal mechanism which can be applied to a noisy and partially observed system that exhibits nonlinear dynamics is a challenging problem, and is the focus of this paper. By partitioning the process into two parts, one that accounts for nonlinear dynamics in a deterministic way, and another as a residual stochastic process, we develop a class of novel constructs that bridge the residual process via a linear approximation. In addition, we adapt a recently proposed construct to a partial and noisy observation regime. We compare the performance of each new construct with a number of existing approaches, using three applications.     

Access to justice for Aboriginal People in the Northern Territory

This article discusses research in the Northern Territory on Aboriginal civil and family law needs. It is based on focus group discussions and interviews with legal services providers and other associated organisations. The article argues that key areas of legal need involve discrimination, housing, child protection, social security, credit/debt and consumer law problems. It further argues that welfare conditionality, particularly as embodied in the NT Intervention and subsequent Stronger Futures policies, has exacerbated the need for legal assistance and advocacy for Aboriginal people.     

The Effects of Corporate Elitism and Groupthink on Organizational Empathy in Crisis Situations

This study is to empirically testify that corporate elitism is an antecedent to groupthink, which prevents organizational empathy from working effectively in crises. The current study is expected to expand the boundary of crisis management literature into a company’s crisis-preparedness before a crisis occurs. The findings offer the useful guidance to organizations on how to better manage their crisis proneness through identifying the early signs of corporate elitism and groupthink.     

Young Adult and Parent Perceptions of Facilitation: Associations with Overparenting,Family Functioning,and Student Adjustment

Overparenting occurs when parents engage in developmentally inappropriate involvement in their children’s lives. This topic is salient in the context of young adults attending college, as this developmental stage necessitates independent decision-making and adjustment on the part of these students. At the same time, the turbulence involved in this transition might engender parental interference and facilitation that could impact young adults’ adjustment and perceived family functioning. This study used structural equation modeling to examine overparenting, perceived interference, facilitation, student adjustment, and family functioning in 302 parent–young adult dyads. Results indicated that overparenting was associated with facilitation, but not interference. Whereas this association was negative for young adults, it was positive for parents. This pattern was also reflected in the indirect effects of overparenting on student adjustment through young adults’ versus parents’ perceived facilitation. Young adults appear to have better outcomes when they perceive their parents to be facilitating their goals.     

Hypothesis Tests for Neyman's Bias in Case–Control Studies

Survival bias is a long recognized problem in case–control studies, and many varieties of bias can come under this umbrella term. We focus on one of them, termed Neyman's bias or ‘prevalence–incidence bias’. It occurs in case–control studies when exposure affects both disease and disease-induced mortality, and we give a formula for the observed, biased odds ratio under such conditions. We compare our result with previous investigations into this phenomenon and consider models under which this bias may or may not be important. Finally, we propose three hypothesis tests to identify when Neyman's bias may be present in case–control studies. We apply these tests to three data sets, one of stroke mortality, another of brain tumors, and the last of atrial fibrillation, and find some evidence of Neyman's bias in the former two cases, but not the last case.     

Deep Uncertainties in Sea-Level Rise and Storm Surge Projections: Implications for Coastal Flood Risk Management

Sea levels are rising in many areas around the world, posing risks to coastal communities and infrastructures. Strategies for managing these flood risks present decision challenges that require a combination of geophysical, economic, and infrastructure models. Previous studies have broken important new ground on the considerable tensions between the costs of upgrading infrastructure and the damages that could result from extreme flood events. However, many risk-based adaptation strategies remain silent on certain potentially important uncertainties, as well as the tradeoffs between competing objectives. Here, we implement and improve on a classic decision-analytical model (Van Dantzig 1956) to: (i) capture tradeoffs across conflicting stakeholder objectives, (ii) demonstrate the consequences of structural uncertainties in the sea-level rise and storm surge models, and (iii) identify the parametric uncertainties that most strongly influence each objective using global sensitivity analysis. We find that the flood adaptation model produces potentially myopic solutions when formulated using traditional mean-centric decision theory. Moving from a single-objective problem formulation to one with multiobjective tradeoffs dramatically expands the decision space, and highlights the need for compromise solutions to address stakeholder preferences. We find deep structural uncertainties that have large effects on the model outcome, with the storm surge parameters accounting for the greatest impacts. Global sensitivity analysis effectively identifies important parameter interactions that local methods overlook, and that could have critical implications for flood adaptation strategies.     

Ethnographies of Volunteering: Providing Nuance to the Links Between Volunteering and Development

VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - This paper explores how ethnographic approaches to third sector and nonprofit studies allow for context-based...     

Men,masculinities, and gender-based violence: The broadening scope of recent research

Men's relationships to gender-based violence (GBV) have long been an area of sociological inquiry, but until recently men have primarily been framed as perpetrators of violence against women. More recently, research on men and GBV has broadened to include studying men as victims/survivors, as investigators and law enforcement officers, as passive or active bystanders, and as allies in working to address this social problem. We review this research in an effort to bridge these divergent bodies of work; we identify methodological trends and gaps in existing research, make recommendations for improved theoretical and methodological robustness, and suggest that research perspectives on men and GBV have shifted over time as wider understandings of gender and masculinities become more hopeful and more inclusive. While we see optimism and promise in new directions of GBV research, we urge ongoing research to retain the wisdoms and critical perspectives that marked the beginnings of GBV inquiry.     

Social inclusion through employment: the marketisation of employment support for people with learning disabilities in the United Kingdom

Employment for people with learning difficulties is considered key to their social inclusion. This contradicts the perceived un-employability of people with learning difficulties that has been part of their social identities throughout their history hitherto. The national rate of employment for people with learning difficulties remains extremely low and has barely changed in the 20?years between 1990 and 2010. This paper investigates links between learning disabilities and employment, drawing on interview-based research. It analyses the quality of experience of the minority in employment to consider whether employment can serve the inclusive purpose expected of it.