Perceptions of the Neighborhood Environment Associated With Walking at Recommended Intensity and Volume Levels in Recreational Senior Walkers

This study examined the relationship of perceived neighborhood environment factors with recommended volume and intensity of walking in recreational senior walkers. A sample of 85 seniors used an accelerometer and completed the ALPHA questionnaire. Binomial logistic regressions were conducted to detect associations. Perceptions about traffic safety (odds ratio [OR] = 4.395; 95% confidence interval [CI] = 1.024; 18.866) and pleasant environment (OR = 8.718; 95% CI = 1.803; 42.149) were positively related with the achievement of 10,000 steps per day, in older women. The perception of nearby parks was positively associated with the compliance with peak 30-minutes cadence above 100, in older men (OR = 14.353; CI 95% = 1.321; 15.591). No more significant associations were found between perceptions of the neighborhood environment and walking at recommended intensity and volume levels. These results indicated that community initiatives that encourage traffic safety, pleasant environment, and parks may be a promising direction to promote walking at recommended volume and intensity in senior walkers.     

Professional judgements and decisions on placement in foster care and reunification in Portugal

This study aims to analyse professional judgements and decisions made in the Portuguese child care system in face of a case vignette of child maltreatment. Using the approach proposed by Benbenishty et al. [(2015). Decision making in child protection: An international comparative study on maltreatment substantiation, risk assessment and interventions recommendations, and the role of professionals’ child welfare attitudes. Child Abuse & Neglect, 49, 63–75. doi:10.1016/j.chiabu.2015.03.015], we assessed the decisions of professionals, such as to place the child in foster care or reunify her with her family, on the basis of a series of judgements (e.g. substantiation of alleged abuse and neglect, risk assessments) that are influenced by the characteristics of the case, the decision-making context, and mother's and child's wishes. We conclude that there are different approaches to the case based on different professionals' attitudes that can be classified in two groups: one more pro-removal and the other anti-removal. These groups presented different risk assessments and intervention recommendations, and their decisions where significantly influenced by the mother's and child's wishes. Furthermore, we have done comparisons with studies made in other countries, concluding that the country context can be an important factor that leads to different outcomes. Implications for both practice and research are presented.     

Interval-censored data with misclassification: a Bayesian approach

Survival data involving silent events are often subject to interval censoring (the event is known to occur within a time interval) and classification errors if a test with no perfect sensitivity and specificity is applied. Considering the nature of this data plays an important role in estimating the time distribution until the occurrence of the event. In this context, we incorporate validation subsets into the parametric proportional hazard model, and show that this additional data, combined with Bayesian inference, compensate the lack of knowledge about test sensitivity and specificity improving the parameter estimates. The proposed model is evaluated through simulation studies, and Bayesian analysis is conducted within a Gibbs sampling procedure. The posterior estimates obtained under validation subset models present lower bias and standard deviation compared to the scenario with no validation subset or the model that assumes perfect sensitivity and specificity. Finally, we illustrate the usefulness of the new methodology with an analysis of real data about HIV acquisition in female sex workers that have been discussed in the literature.     

Smoking Risks in Spain: Part I—Perception of Risks to the Smoker

Survey evidence for the Spanish population indicates that perceptions of lung cancer risk and life expectancy loss due to smoking are similar to estimates found in the United States. This paper also presents new evidence on the relative lung cancer risk for smokers, the perceived risk of lung disease for smokers, the heart disease risk for smokers, and the relative heart disease risk for smokers, all of which indicate substantial risk perceptions. Risk beliefs are particularly high for younger respondents, but are lower for better educated respondents.     

Model comparison for a complex ecological system

Summary.  The ecological consequences of climate change and its interaction with other environmental pressures, such as nutrient pollution, are little understood. For freshwater ecosystems, knowledge of these combined effects is required for water resource management and in particular for successful implementation of the European Community Water Framework Directive 2000, which requires that all surface-waters should be at, or above, 'good status' by 2016. Statistical analysis of detailed long-term environmental data sets can be used to explore these combined effects. Loch Leven (Scotland) has been routinely monitored since 1967, providing one of the largest and most extensive of such data sets. Over this period there has been evidence of climate change and a period of eutrophication and recovery at the loch. Transfer functions, additive models and varying-coefficient models are used to explore the complex ecological system at Loch Leven with the aim of obtaining insight into the combined effects of climate change and eutrophication on water quality.     

Factor stochastic volatility with time varying loadings and Markov switching regimes

We generalize the factor stochastic volatility (FSV) model of Pitt and Shephard [1999. Time varying covariances: a factor stochastic volatility approach (with discussion). In: Bernardo, J.M., Berger, J.O., Dawid, A.P., Smith, A.F.M. (Eds.), Bayesian Statistics, vol. 6, Oxford University Press, London, pp. 547–570.] and Aguilar and West [2000. Bayesian dynamic factor models and variance matrix discounting for portfolio allocation. J. Business Econom. Statist. 18, 338–357.] in two important directions. First, we make the FSV model more flexible and able to capture more general time-varying variance–covariance structures by letting the matrix of factor loadings to be time dependent. Secondly, we entertain FSV models with jumps in the common factors volatilities through So, Lam and Li's [1998. A stochastic volatility model with Markov switching. J. Business Econom. Statist. 16, 244–253.] Markov switching stochastic volatility model. Novel Markov Chain Monte Carlo algorithms are derived for both classes of models. We apply our methodology to two illustrative situations: daily exchange rate returns [Aguilar, O., West, M., 2000. Bayesian dynamic factor models and variance matrix discounting for portfolio allocation. J. Business Econom. Statist. 18, 338–357.] and Latin American stock returns [Lopes, H.F., Migon, H.S., 2002. Comovements and contagion in emergent markets: stock indexes volatilities. In: Gatsonis, C., Kass, R.E., Carriquiry, A.L., Gelman, A., Verdinelli, I. Pauler, D., Higdon, D. (Eds.), Case Studies in Bayesian Statistics, vol. 6, pp. 287–302].     

High-Dimensional Sparse Factor Modeling: Applications in Gene Expression Genomics

We describe studies in molecular profiling and biological pathway analysis that use sparse latent factor and regression models for microarray gene expression data. We discuss breast cancer applications and key aspects of the modeling and computational methodology. Our case studies aim to investigate and characterize heterogeneity of structure related to specific oncogenic pathways, as well as links between aggregate patterns in gene expression profiles and clinical biomarkers. Based on the metaphor of statistically derived "factors" as representing biological "subpathway" structure, we explore the decomposition of fitted sparse factor models into pathway subcomponents and investigate how these components overlay multiple aspects of known biological activity. Our methodology is based on sparsity modeling of multivariate regression, ANOVA, and latent factor models, as well as a class of models that combines all components. Hierarchical sparsity priors address questions of dimension reduction and multiple comparisons, as well as scalability of the methodology. The models include practically relevant non-Gaussian/nonparametric components for latent structure, underlying often quite complex non-Gaussianity in multivariate expression patterns. Model search and fitting are addressed through stochastic simulation and evolutionary stochastic search methods that are exemplified in the oncogenic pathway studies. Supplementary supporting material provides more details of the applications, as well as examples of the use of freely available software tools for implementing the methodology.     

Estimating the stability of census-based racial/ethnic classifications: the case of Brazil

This study presents a method of estimating the degree to which people change their racial/ethnic identity from one census enumeration to another. The technique is applied to the classification of skin colour in Brazil (white, black, brown, yellow). For the period 1950-80, the findings show a deficit of 38 per cent in the black category and a gain of 34 per cent in the brown category, suggesting that a large proportion of individuals who declared themselves black in 1950 reclassified themselves as brown in 1980. Estimates for 1980-90, adjusted for the effects of international migration, reveal a similar pattern, although the magnitude of colour reclassification may have declined somewhat during the 1980s. Procedures to determine the stability of racial/ethnic identity produce data useful to recent policy initiatives that rely on demographic censuses to measure changes in the status of minority groups in less developed countries.     

Violence in the Brazilian favelas and the role of the police

Institutions should normally have an integrative influence. The family, for example, has the task of protecting and giving socio-emotional support to children, and schools should prepare young people for their future. Ideally the common goal of all of society's institutions is to secure the integration of youth and prevent or intervene against deviant behavior. But sometimes institutions provoke or even cause juvenile delinquency. The article discusses institutional influences and the role of the police in the criminal and violent situation in the favelas of Rio de Janeiro.Starting with an overview of the origins and the development of violence, crime, and drug trafficking in the favelas, the authors show how these slums arose. Their analysis examines the lack of a state presence with an integration policy to avoid social disintegration. Instead of social integration policy, there is a dual approach that both controls and produces violence. The article also presents the first results of a government attempt in 2000 to introduce a new police unit to stop the violence and improve the social opportunity structure of the residents of the favelas, especially young people.     

Work-to-Family Enrichment and Employees’ Well-Being: High Performance Work System and Job Characteristics

Research has demonstrated the importance of job characteristics to explain work-to-family enrichment (WFE) and the value of this enrichment to explain employees’ wellbeing. However, there is no comprehensive framework to explain the relationship between these variables. This study uses the Job Demands-Control-Support model as a guiding framework, and examines the relationship between these job characteristics and WFE and, more interestingly, the WFE as a mechanism for explaining the relationship between job characteristics and employees’ well-being. Furthermore, we analyzed the relationship of employees’ perceptions of High Performance Work System (HPWS) with job characteristics. With a sample of 1,390 employees from a Portuguese bank, job demands were found to be negatively related to WFE while autonomy and supervisor support displayed a positive relation. We also observed that WFE is an important mechanism to explain the relationship between these job characteristics and employees’ well being. As expected, HPWS was a relevant organizational characteristic to explain job characteristics, however, we observed that it was also directly related to WFE.