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.     

Depressive Symptoms,Acute Alcohol Intoxication,and Risk Rationale Effects on Men’s Condom Use Resistance

This study examined the role of depressive symptoms, acute intoxication, and risk rationale in men’s use of condom use resistance (CUR) tactics in an experimental study. Participants included 313 heterosexual male, nonproblem drinkers, ages 21 to 30. Participants were randomized to one of four beverage conditions: no alcohol, placebo, low (.04%) alcohol dose, or high (.08%) alcohol dose. They read an eroticized scenario depicting a consensual sexual encounter with a female partner who requested a condom to prevent either pregnancy or sexually transmitted infections (STIs) (risk rationale) and then indicated their intentions to use 10 different CUR tactics. Hypotheses related to the pharmacological, dosage, and expectancy effects of alcohol were tested in a generalized linear model. In intoxicated (.04% and .08%) men who were given a pregnancy risk rationale, depressive symptoms were associated with stronger intentions to use CUR tactics than in sober (control and placebo) men. Men who received a high alcohol dose (.08%) and who were given a pregnancy risk rationale reported higher intentions to use CUR tactics than those who received a lower alcohol dose (.04%). Findings suggest that the pharmacological effects of alcohol on men’s likelihood to resist condoms vary by the saliency of the risk rationale and mood-related variables.     

A Preliminary Evaluation of the 1-2-3-Magic Parenting Program in an Australian Community Services Setting

Cognitive-behavioural parenting programs provide caregivers with alternative strategies to harsh disciplining practices but the choice of programs that are evidence-based in Australia is limited. Australian community service workers suggest that having a choice of evidence-based programs is important when matching programs to client needs, and that 1-2-3 Magic is a program used widely in Australia despite its small Australian evidence base. The efficacy of the 1-2-3 Magic program has previously been shown in a controlled trial in an Australian university research setting but little is known about its effectiveness in a “real-world” setting. This study examined a three-session group-format of the Australian 1-2-3 Magic & Emotion Coaching program in a typical metropolitan community service setting. Thirty-eight caregivers with children aged 2–6 years reported a significant decrease in disruptive child behaviour (ECBI), permissive parenting (PS), and parental depression and stress (DASS) from pre- to post-intervention, with results maintained at 3-month follow-up. While these findings suggest that a brief 1-2-3 Magic program is beneficial, it is important to note that methodological limitations (intervention-group only study design and possible confounding variables) do not allow ruling out alternative causes for these improvements. Further research will be needed to confirm that this program can generalise to “real-world” settings.     

The heritability of emergent leadership: Age and gender as moderating factors

In this study, we examined the moderating influences of gender and age with respect to testing the heritability of leadership emergence. A large data base of 12,112 twins from Sweden was used in the current study to decompose the variance of emergent leadership into an unobservable genetic component and environmental components that are either common or unshared among twin pairs. Consistent with prior leadership research on genetics, we found that a genetic factor is able to explain a significant proportion of the variation across individuals in predicting how twins perceive their emergent leadership behavior (about 44% for women and 37% for men). Furthermore, we also found that the magnitude of genetic influence on emergent leadership varied with age, but only for women with the heritability estimate being highest for the mid-age women versus lowest for the older women. Implications for advancing research on the genetic and environmental influences on leadership emergence are discussed.     

Of politics,self-preservation,and symbolism: An investigation of jurisdiction-stripping and legislative redistricting

Jurisdiction-stripping has long been a questionable component of Congress's power to supervise the judiciary's policymaking role. It has gained notoriety in recent debates surrounding judicial involvement in areas including religious establishment and privacy issues such as abortion and same-sex marriage. Most scholarship equates the advocacy of jurisdiction-stripping measures with symbolic position-taking that is unmotivated by the goal of traditional policy success. This work, a quantitative case study of the first such measure to pass the House of Representative since Reconstruction, seeks to isolate legislative motivations for exerting jurisdictional controls against the Supreme Court. Legislators’ votes on this measure were multifaceted. While those decisions were guided in part by the symbolic and representational considerations that traditionally underlie the advocacy of such legislation, there is also evidence more substantive motivations played a part. The study highlights the evolving objectives of jurisdiction-stripping's advocates and, more broadly, Congress's objectives vis-à-vis the courts.     

Experienced Well-Being and Labor Market Status: The Role of Pleasure and Meaning

Social Indicators Research - This paper examines the experienced well-being of employed and unemployed workers. We use the survey-adapted Day Reconstruction Method of the Innovation Sample of the...     

Social Evolution and Environmental Context: Explanative Pluralism and Potentiality

We identify four common, but we argue fallacious, reasons social scientists object to theories that rely on environmental conditions to explain variation in the evolution of societies. First, some sociologists exclude environmental forces as beyond the domain of sociology. Second, environmental theories are often pejoratively labeled “determinist,” and rejected on those grounds. Third, environmental theories are regularly dismissed as being functionalist. Fourth, environmental theories are frequently charged with being Eurocentric and serving to justify colonialism and social inequalities. We argue that although there are examples of theories that fail in these regards, there is no inherent reason that environmental theories are more prone to these limitations and problems than are more sociologically “pure” theories. We argue that sociology should strive to be more transdisciplinary and can benefit from consideration of environmental conditions.     

Learning from others: conditioning versus averaging

How should we revise our beliefs in response to the expressed probabilistic opinions of experts on some proposition when these experts are in disagreement? In this paper I examine the suggestion that in such circumstances we should adopt a linear average of the experts’ opinions and consider whether such a belief revision policy is compatible with Bayesian conditionalisation. By looking at situations in which full or partial deference to the expressed opinions of others is required by Bayesianism I show that only in trivial circumstances are the requirements imposed by linear averaging compatible with it.