Developmental Shifts in Parent and Peer Influences on Boys' Beliefs About Delinquent Behavior

This paper examines the relative shifts in parent and peer influences on the development of boys' beliefs regarding delinquency from early to middle adolescence. The paper also explores the influence that beliefs about delinquency have on subsequent changes in these social relationships. Structural equation modeling is used to analyze six annual waves of data for 481 boys from the youngest sample of the Pittsburgh Youth Study. Increased parent–adolescent conflict only predicted changes in beliefs about delinquency in early adolescence, while increases in peer delinquency was associated with adopting more tolerant beliefs about delinquent acts from early to middle adolescence. Changes in boys' delinquent peer group association were initially influenced by increased family conflict. However, in middle adolescence increasingly tolerant beliefs about delinquency were related to subsequent increases in delinquent peers. The potential implications for preventing the formation of beliefs favoring delinquency during adolescence are discussed.     

Musculoskeletal symptoms and work ability among agricultural machinery operators

Those subjects whose employment has physical demands present more frequently musculoskeletal symptoms than others. The agricultural sector activities include tasks with important physical demands that may have a negative impact in the workers health. The aim of this study was to evaluate the presence of musculoskeletal symptoms and its association with work ability in agricultural machinery operators. It is a cross-sectional study. The participants (n = 204) answered a self-administered questionnaire on demographics, work and lifestyle characteristics, Work Ability Index and the Nordic Musculoskeletal Symptoms Questionnaire. The response rate was 89.78%. The mean age of the workers was 32.3 years, and 47.1% of them reported musculoskeletal symptoms at least one body part over the past 12 months. Those subjects who presented work ability index <37 points, 87.5% reported some kind of musculoskeletal symptom. This study showed that the work ability was significantly (p ≤ 0.05) correlated to musculoskeletal symptoms presence. It is recommended that measures to promote and improve the work ability are designed and deployed based on musculoskeletal disorders prevention.     

Ports of Mucuripe and Pecém, Ceará, Brazil: restructuring process and its impact on workers' health

This paper presents a comparative study of working conditions and health hazards of two ports in the state of Ceará: Mucuripe and Pecém, focusing workers in the various categories involved in the operational activities of the two ports. The aim is to investigate changes implemented by the restructuring process of ports arising from the Port Modernization Act. In the case of Ceará, the organization and control of work at the mentioned ports occur differently: Mucuripe, the oldest port, had to adapt to the changes enforced by the Modernization Act and Pecém, called Port Terminal, inaugurated in 2001, "was born modern". To achieve our objective, we carried out field work, using Ergonomic Work Analysis. Systematic observations were made of the various activities carried out by workers, as well as interviews with managers, workers and trade unionists. Container operations and other activities of the two ports were recorded in film and presented to groups of workers (focus groups) in order to better understand work organization and the main differences in tasks carried out in the two ports. Each reality presents different characteristics regarding port operations, type of work and labor control. Results indicate that due to the technological innovations, the restructuring process reduced some risks, but brought new occupational hazards and intensification of work.     

Client experiences with perinatal healthcare for high-risk and low-risk women

Problem

It is unknown if client experiences with perinatal healthcare differ between low-risk and high-risk women.

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.     

PRICE FLEXIBILITY AND AGGREGATE STABILITY: NEW EVIDENCE AND IMPLICATIONS

The relation between price flexibility and aggregate real stability has been subject to recent debate. Increased price flexibility decreases the response of real output to aggregate demand shifts and, in turn, is stabilizing. The increased flexibility may exacerbate, however, the size of demand shifts induced by a given underlying shock. If the latter channel dominates, increased flexibility may prove destabilizing. This paper examines the real effects of specific shocks underlying aggregate demand across a group of eighteen major industrial countries. The stabilizing effect of price flexibility appears to dominate.     

Integer-Valued Self-Exciting Threshold Autoregressive Processes

In this article, we introduce a class of self-exciting threshold integer-valued autoregressive models driven by independent Poisson-distributed random variables. Basic probabilistic and statistical properties of this class of models are discussed. Moreover, parameter estimation is also addressed. Specifically, the methods of estimation under analysis are the least squares-type and likelihood-based ones. Their performance is compared through a simulation study.     

Psychosocial Assistance for Youth: Toward Reconstruction for Peace in Angola

Following decades of war, Angolan youth are at risk of continuing cycles of violence and need support in developing positive behaviors and social roles. Accordingly, a community-based program, conducted in Angola 1998–2001, taught youth life skills, provided peer support and peace education, educated adults about youth, and engaged youth as workers on community development projects. The main results included increased adult awareness of the situation and needs of youth, improved youth-adult relations, reduced perceptions of youth as troublemakers, reduced fighting between youth, increased community planning, and increased perceptions that youth make a positive contribution to the community. The results suggest that a dual focus on youth and community development contributes to peacebuilding and the disruption of cycles of violence.     

Paired domination versus domination and packing number in graphs

Journal of Combinatorial Optimization - Given a graph $$G=(V(G), E(G))$$ , the size of a minimum dominating set, minimum paired dominating set, and a minimum total dominating set of a graph G are...