A flexible particle Markov chain Monte Carlo method

Particle Markov Chain Monte Carlo methods are used to carry out inference in nonlinear and non-Gaussian state space models, where the posterior density of the states is approximated using particles. Current approaches usually perform Bayesian inference using either a particle marginal Metropolis–Hastings (PMMH) algorithm or a particle Gibbs (PG) sampler. This paper shows how the two ways of generating variables mentioned above can be combined in a flexible manner to give sampling schemes that converge to a desired target distribution. The advantage of our approach is that the sampling scheme can be tailored to obtain good results for different applications. For example, when some parameters and the states are highly correlated, such parameters can be generated using PMMH, while all other parameters are generated using PG because it is easier to obtain good proposals for the parameters within the PG framework. We derive some convergence properties of our sampling scheme and also investigate its performance empirically by applying it to univariate and multivariate stochastic volatility models and comparing it to other PMCMC methods proposed in the literature.     

PREDICTING MARITAL SUCCESS WITH PREPARE: A PREDICTIVE VALIDITY STUDY

In order to determine the predictive validity of the premarital inventory PREPARE, this study assessed the utility of PREPARE inpredicting marital success. A 3-year follow-up study was conducted with 164 couples who took PREPARE during their engagement. As hypothesized, it was found that satisfied couples scored significantly higher on the inventory than dissatisfied couples, divorced couples, and couples who cancelled their marriage. It was also hypothesized and found that dissatisfied married couples did not differ significantly from couples who cancelled their marriage or those who divorced. Using discriminant analysis, it was found that the PREPARE scores from 3 months before marriage could predict with 80–90% accuracy which couples were separated and divorced from those that were happily married. These findings not only demonstrate the predictive validity of PREPARE, but its potential utility in identifying high-risk couples who could benefit from more intensive premarital counseling.     

Baby talk to the babyfaced

The power of an infantile appearance to elicit baby talk was investigated by assessing the use of baby talk in task instructions to four-year-old children, who were portrayed as either relatively babyfaced or maturefaced. Men and women taught two tasks to a randomly selected boy or girl via a telephone conversation after being shown a photograph, which presumably depicted the child whom they were instructing. Paralleling facial differences between babies and adults, babyfaced children had rounder faces, larger eyes, thinner eyebrows, and smaller noses than the maturefaced. As predicted, adults used more baby talk when instructing babyfaced than maturefaced children. This effect was manifested in linguistic indicators of baby talk (slow timing and high clarification, simplification, and attention maintenance), as well as in paralinguistic indicators of baby talk (high pitch and changing intonation). The receipt of linguistic baby talk, in turn, facilitated the child's ability to choose a card which matched the one being described. The fact that facial babyishness influenced baby talk even when baby- and maturefaced children were equated in age, attractiveness, and perceived competence suggests that a small approximation to the craniofacial qualities that distinguish infants from adults may in and of itself be sufficient to elicit this speech register.This research was supported by NIMH grant #BSR5 R01 MH42684 to the first author. The authors would like to express their appreciation to the Brandeis University and Wellesley College Daycare Centers for their cooperation in this research. Thanks are also extended to Stacy Silberman for serving as one of the experimenters and to Becky Gilbert, Katina Lawdis, Sheryl Levy, and Liz Tighe for their help in coding the data.     

Extended structures of mediation: Re-examining brokerage in dynamic networks

In this paper we revisit the concept of brokerage in social networks. We elaborate on the concept of brokerage as a process, identifying three distinct classes of brokerage behavior. Based on this process model, we develop a framework for measuring brokerage opportunities in dynamic relational data. Using data on emergent inter-organizational collaborations, we employ the dynamic brokerage framework to examine the relationship between organizational attributes and coordination in the evolving network. Comparing the findings of our process-based definition with traditional, static approaches, we identify important dimensions of organizational action that would be missed by the latter approach.     

A model-based sample selection procedure for one-stage sampling

The problem of sample selection, when a one-stage superpopulation model-based approach is used to predict individual variate values for each unit in a finite population based on a sample of only some of the units, is investigated. The model framework is discussed and a sample selection scheme based on the model is derived. The sample selection scheme is evaluated using actual data. Future research topics including multiple predictions per unit are suggested.     

Racial Resentment and Attitudes Toward the Use of Force by Police: An Over‐Time Trend Analysis

On the heels of recent police shootings of an unarmed Michael Brown in Ferguson, Missouri, Walter Scott in North Charleston, South Carolina, and the death of Freddy Gray in Baltimore, Maryland, that stoked racial tensions, this article examines how beliefs about race and racial inequality influence whites’ attitudes toward the use of force by the police since the mid‐1980s. Our main dependent measure is a composite index (“Police Force Index”) constructed from four survey items from the 1986–2012 National Opinion Research Center's General Social Survey (GSS). Results show that (1) beliefs about race do indeed significantly predict whites’ attitudes toward police use of force, and more importantly, (2) this effect has remained constant since the mid‐1980s. We discuss theoretical and practical implications of these findings and suggestions for future research.     

Estimating the Probability of Human Error by Incorporating Component Failure Data from User-Induced Defects in the Development of Complex Electrical Systems

This article proposes a methodology for incorporating electrical component failure data into the human error assessment and reduction technique (HEART) for estimating human error probabilities (HEPs). The existing HEART method contains factors known as error-producing conditions (EPCs) that adjust a generic HEP to a more specific situation being assessed. The selection and proportioning of these EPCs are at the discretion of an assessor, and are therefore subject to the assessor's experience and potential bias. This dependence on expert opinion is prevalent in similar HEP assessment techniques used in numerous industrial areas. The proposed method incorporates factors based on observed trends in electrical component failures to produce a revised HEP that can trigger risk mitigation actions more effectively based on the presence of component categories or other hazardous conditions that have a history of failure due to human error. The data used for the additional factors are a result of an analysis of failures of electronic components experienced during system integration and testing at NASA Goddard Space Flight Center. The analysis includes the determination of root failure mechanisms and trend analysis. The major causes of these defects were attributed to electrostatic damage, electrical overstress, mechanical overstress, or thermal overstress. These factors representing user-induced defects are quantified and incorporated into specific hardware factors based on the system's electrical parts list. This proposed methodology is demonstrated with an example comparing the original HEART method and the proposed modified technique.     

Efficacy of newer medications for lower urinary tract symptoms attributed to benign prostatic hyperplasia: a systematic review

We conducted a systematic review to evaluate the efficacy and adverse effects of newer drugs used to treat lower urinary tract symptoms (LUTS). The drugs were either Food and Drug Administration (FDA) approved for benign prostatic hyperplasia (BPH) or not FDA approved for BPH but have been evaluated for treatment of BPH since 2008. We searched bibliographic databases through September 2017. We included randomized controlled trials (RCTs) lasting one month or longer published in English. Outcomes of interest were LUTS assessed by validated measures. Efficacy was interpreted using established thresholds indicating clinical significance that identified the minimal detectable difference. Twenty-three unique, generally short-term, RCTs evaluating over 9000 participants were identified. Alpha-blocker silodosin and phosphodiesterase type 5 inhibitor tadalafil were more effective than placebo in improving LUTS (moderate strength evidence) but these drugs had more adverse effects, including abnormal ejaculation (silodosin). Anticholinergics were only effective versus placebo when combined with an alpha-blocker. Evidence was generally low strength or insufficient for other drugs. Evidence was insufficient to assess long-term efficacy, prevention of symptom progression, need for surgical intervention, or long-term adverse effects. Longer trials are needed to assess the effect of these therapies on response rates using established minimal detectable difference thresholds, disease progression, and harms.     

Gender Performances During Labor and Birth in the Midwives Model of Care

Previous research suggests many middle-class white women attempt to maintain femininity during labor and birth. There is also evidence that women who give birth outside the medical model may engage in more gender-deviant behaviors. The current study examines women’s accounts of gender performances during birth in the midwives model of care. Participants describe themselves engaging in a number of gender-deviant behaviors, without apology or overt remorse. However, participants also describe themselves engaging in activities during labor and birth that are traditionally considered feminine, including domestic tasks, care-giving and adhering to beauty norms; some defined childbirth itself as a feminine activity. Thus, participants are not simply adhering to or defying dominant notions of femininity, but are engaging in a complex set of gender behaviors. It is argued that study participants are prioritizing certain aspects of femininity—in particular, the “good mother”—over others.