Bayesian credible intervals for response surface optima

In response surface methodology, one is usually interested in estimating the optimal conditions based on a small number of experimental runs which are designed to optimally sample the experimental space. Typically, regression models are constructed from the experimental data and interrogated in order to provide a point estimate of the independent variable settings predicted to optimize the response. Unfortunately, these point estimates are rarely accompanied with uncertainty intervals. Though classical frequentist confidence intervals can be constructed for unconstrained quadratic models, higher order, constrained or nonlinear models are often encountered in practice. Existing techniques for constructing uncertainty estimates in such situations have not been implemented widely, due in part to the need to set adjustable parameters or because of limited or difficult applicability to constrained or nonlinear problems. To address these limitations a Bayesian method of determining credible intervals for response surface optima was developed. The approach shows good coverage probabilities on two test problems, is straightforward to implement and is readily applicable to the kind of constrained and/or nonlinear problems that frequently appear in practice.     

Using Bayesian graphical models to model biases in observational studies and to combine multiple sources of data: application to low birth weight and water disinfection by-products

Summary.  Data in the social, behavioural and health sciences frequently come from observational studies instead of controlled experiments. In addition to random errors, observational data typically contain additional sources of uncertainty such as missing values, unmeasured confounders and selection biases. Also, the research question is often different from that which a particular source of data was designed to answer, and so not all relevant variables are measured. As a result, multiple sources of data are often necessary to identify the biases and to inform about different aspects of the research question. Bayesian graphical models provide a coherent way to connect a series of local submodels, based on different data sets, into a global unified analysis. We present a unified modelling framework that will account for multiple biases simultaneously and give more accurate parameter estimates than standard approaches. We illustrate our approach by analysing data from a study of water disinfection by-products and adverse birth outcomes in the UK.     

Population Measures of Subjective Wellbeing: How Useful are they?

This article focuses on the contributions and, importantly, the limitations of subjective wellbeing (happiness/satisfaction) measures as indicators of broad population wellbeing and societal functioning. The popular practice of comparing happiness among countries gives a skewed view of how well their people are faring. Charting trends over time in happiness and mental health gives contradictory pictures of population wellbeing; even the responses to different questions within the same survey can yield very different findings. Asking people about their own lives and about social conditions produces contrasting results. These issues challenge the orthodox model of human development, which places Western liberal democracies at its leading edge. According to an alternative, psychosocial-dynamics, model, some, at least, may be societies in decline. Reconciling these views is no simple matter.     

Racial Disparities in Early Criminal Justice Involvement

Criminologists have long reported the existence of racial disparity in the criminal justice system, but the important question is why. While some argue that observed differences are a consequence of more criminal behavior among minorities, the weight of the evidence indicates that this is but a partial explanation. In this paper, we study data from a sample of juveniles to examine how racial differences in early police contact, and important social environments—family, school, and neighborhoods—affect later contact and arrests, controlling for self-reported delinquency. We find that early (in middle school) contact with police is an important predictor of later (high school) arrests. Also we found that, in addition to being male and living in a low-income family, children who have parents who have a history of arrest, who have experienced school disciplinary actions, who have delinquent peers, and who are in networks with deviant adults are more likely to have problems with law enforcement. These factors help to explain racial differences in police contacts and arrests.     

Improving outcomes for children in out‐of‐home care: the role of therapeutic foster care

How best to support children and young people in foster care remains a challenge for child welfare. There has been little Australian research on the outcomes for children and young people placed in therapeutic foster care (TFC). This article aims to address this knowledge gap, presenting the evaluation of a state‐wide model of TFC known as the Circle Program operating in Victoria, Australia. Data sources for the study were case assessment analysis; surveys of foster carers, program workers and other stakeholders in the sector; and both focus groups and individual interviews with foster care workers. The evaluation found that the Circle Program lessened the number of unplanned exits of children from foster placements compared with generalist foster care. Another important finding was that the Circle Program positively influenced foster carers' decisions to stay in the carer role. Key components perceived as contributing to outcomes of the Circle Program included enhanced training of foster carers, intensive carer support, specialist therapeutic support to the child and carer, therapeutic service to family members and a network of services to provide support to the child.     

Applying a Positive Youth Development Perspective to Observation of Bereavement Camps for Children and Adolescents

A positive youth development perspective focuses on recognizing psychosocial strengths and providing social environments that contribute to the development of these in children and adolescents. Bereavement camps can provide such an environment as they help children cope with the death of someone close. The purpose of this study was to observe bereavement camps through the lens of positive youth development to determine the applicability of the eight features of positive developmental settings for describing bereavement camps (safety, appropriate structure, supportive relationships, opportunities to belong, positive norms, support for efficacy, skill building opportunities, integration of family and community). Observational notes were recorded by researchers during on-site visits to three different weekend bereavement camps. Results identified how each element of positive developmental settings was exemplified in either typical camp activities or bereavement-focused activities. For example, assigning campers to cabin groups based on age and gender provided opportunities to belong, and giving campers a comfort object and a big buddy provided supportive relationships. Findings were used to create a positive developmental settings observation checklist for use by bereavement camp practitioners to assess the extent to which each camp provides the requisite elements for promoting positive youth development.     

How Visual is Visual Prediction?

Infants are readily able to use their recent experience to shape their future behavior. Recent work has confirmed that infants generate neural predictions based on their recent experience (Emberson, Richards, & Aslin, 2015) and that neural predictions trigger visual system activity similar to that elicited by visual stimulation. This study uses behavioral methods to ask, how visual is visual prediction? In Experiment 1, we confirmed that when additional trials provide additional visual experience with the experimental shape, infants exhibit a robust novelty preference. In Experiment 2, we removed the visual stimulus from some trials and presented the predictive auditory cue alone, allowing the effects of neural prediction to be assessed. We found no evidence of looking preferences at test, suggesting that visual prediction does not contribute to the computation of visual familiarity. In Experiment 3, we provided infants with a degraded visual stimulus to test whether visual prediction could bias visual perception under ambiguous conditions. Again, we found no evidence of looking preferences at test, suggesting that visual prediction is not biasing perception of an uncertain stimulus. Overall, our results suggest that visual prediction is not visual, in the strictest sense, despite the presence of visual system activation.     

Elevated phosphorus: dynamics during four years of green roof development

Green roofs are emerging engineered ecosystems that provide multiple benefits, but many are constructed with nutrient-rich substrate and have been found to leach out high levels of phosphorus (P) in runoff. It is unclear, however, how long green roofs act as sources of P or what mechanisms are responsible for these net losses. We measured P concentrations in runoff water over 4 years from a 1–5 year old extensive green roof in Cincinnati, OH, USA, produced a model to predict runoff P levels into the future, and validated predictions using runoff from 2 nearby extensive green roofs. P concentrations in runoff from the focal green roof were on par with heavily fertilized agroecosystems and displayed strong seasonal dynamics and a rapid decline over the 4-year study. Runoff measurements and changes in substrate P content over a 2-year period were used to estimate a mass balance for green roof P. P loss from the substrate was substantial (4.55 ± 2.3 g P/m²/yr), but only a small portion of the loss was attributable to leaching of P in runoff (0.19–0.65 g P/m²/yr). Missing P may be attributed to a combination of plant uptake and altered P form and binding strength, but further research is needed to precisely identify the mechanisms of P depletion. Our results also suggest that these and similar extensive green roofs are likely to act as environmentally significant sources of P for 10 or more years following roof installation, highlighting the need for reductions in initial substrate P content.     

Workplace aggression against health care workers,law enforcement officials,and bus drivers: Differences in prevalence,perceptions, and psychological consequences

Investigations into workplace aggression (WPA) remain largely occupation specific, with few studies using a comparative approach. The aim of the present study was to compare the health care, law enforcement, and public transportation sectors with regards to the prevalence of different types of WPA, the perceptions of workers toward WPA, and the psychological consequences of such acts. A cross-sectional survey was completed by 1,774 workers in Canada. Multinomial regressions were utilized to address the objectives. Findings revealed that verbal abuse victimization was particularly common in bus drivers, witnessing death threats was most frequent among law enforcement officials, and witnessing all types of WPA was most common among health care workers. Although bus drivers did not normalize WPA, they feared complaining about violence to their employer and thought it useless to talk it about unless wounds were visible. Fear of complaining about violence to colleagues was prevalent in health care and law enforcement, both sectors in which WPA was normalized. Finally, flashbacks and irritability following WPA were most likely to affect bus drivers whereas health care workers experienced hypervigilance to a greater extent. Strategies to tailor primary, secondary, and tertiary prevention according to these distinctions are suggested to offer a better-informed response to WPA.     

“Friendly” Initiatives: An Emerging Approach to Improve Communities for Vulnerable Populations

A growing number of cities and towns are implementing “friendly” initiatives to change the community’s social and physical infrastructure to address the needs of a particular vulnerable segment of their population. Three prominent examples are aging-friendly, child-friendly, and immigrant-friendly initiatives. Although the limited but growing literature describes these initiatives as promising strategies to improve the quality of life of the targeted population, to date there has been little written about the underlying goals, values, and assumptions of these efforts. Using the value-critical approach, this article aims to better understand these aspects of population-friendly initiatives by examining the scholarly and grey literature. Social workers engaged in community and policy practice can play a key role in these efforts and call attention to the ways they may alleviate or exacerbate inequities. Future research is needed to assess the effects of these initiatives on their targeted population as well as other community residents.