Marginal models for the association structure of hierarchical binary responses

Clustered binary responses are often found in ecological studies. Data analysis may include modeling the marginal probability response. However, when the association is the main scientific focus, modeling the correlation structure between pairs of responses is the key part of the analysis. Second-order generalized estimating equations (GEE) are established in the literature. Some of them are more efficient in computational terms, especially facing large clusters. Alternating logistic regression (ALR) and orthogonalized residual (ORTH) GEE methods are presented and compared in this paper. Simulation results show a slightly superiority of ALR over ORTH. Marginal probabilities and odds ratios are also estimated and compared in a real ecological study involving a three-level hierarchical clustering. ALR and ORTH models are useful for modeling complex association structure with large cluster sizes.     

Adaptation of the short version of the Psychological Capital Questionnaire (PCQ-12) into Spanish / Adaptación al español de la versión reducida del Cuestionario de Capital Psicológico (PCQ-12)

Psychological capital (PsyCap) has been a topic of increasing interest in the last decade. However, there is a lack of validated instruments in Spanish to map PsyCap and its consequences for individuals’ well-being. Consequently, the goal of this study is to adapt the 12-item short version of the Psychological Capital Questionnaire (PCQ-12) to the Spanish context by analysing its internal consistency and reliability, factor solution and external validity. Results indicated that the PCQ-12 exhibited good Cronbach’s alpha (.87) and omega coefficient (.93) values in a sample from a vehicle inspection company (n = 798). As expected, results also revealed that a second-order factor structure provided the best fit. Moreover, PsyCap is associated with increased job engagement (β = .579; R²_adjusted = .333), decreased job burnout (β = ?.409; R²_adjusted = .166), and lower psychological distress (β = ?.349; R²_adjusted = .121) (all p < .01), which provided additional support for using the PCQ-12 in the Spanish context. Implications for theory and practice are discussed.     

Condom Use Trajectories in Adolescence and the Transition to Adulthood: The Role of Mother and Father Support

Few studies have investigated how mother and father support differ on predicting youths' sexual risk behavior. We therefore examined the influence of parental support on condom use trajectories and its correlates in a predominantly African American sample [(N=627; 53% female; M = 14.86 years (SD=. 64)] from adolescence to young adulthood. We used hierarchical growth curve modeling to examine the relationship between condom use, substance use, psychological distress and parental support prospectively. We found that consistent condom use decreased over time and was associated negatively with psychological distress and substance use. Furthermore, both maternal and paternal support were associated with more condom use over time. We discuss the implications of our findings for HIV prevention programs.     

The profile of cyclists in the city of Juiz de Fora

The problems related to the means of transport in urban Brazilians have been getting worse over the years. The increase of the fleet, to the detriment of the adequacy and extent of the road network of cities contributes to this fact. This paper presents a profile of users of cycling in the city of Juiz de Fora, and thus contributes to the study of sustainable urban mobility, providing researchers with information that can guide the search for the encouragement of the use of means of transport to meet environmental needs urban centers that contributes to social equity.     

Thermal comfort and personal protective equipment (PPE)

Personal Protective Equipment (PPE) is considered the last preferred solution to an Occupational Safety Health (OSH) system. Brazilian OSH legislation assumes and requires PPE usage to neutralize the possibility of pesticide contamination. This study examines the inadequacy of the PPE used in a tomato crop, particularly from the standpoint of thermal comfort. This study made observations regarding heart rate and body temperature in a controlled environment using a treadmill (with and without PPE) of 12 volunteers; and during the process of rural labor (at rest and in normal work routine) of 2 actual rural workers. Comparing the results of the treadmill test (with and without PPE) which tried to reproduce the same level of effort and environmental conditions of the actual rural work, this study demonstrated that PPE makes thermoregulation harder and tympanic temperature reaches higher values with the same level of effort. Moreover, body temperature increases quickly: with PPE it took 15 minutes to raise 1°C in body temperature, compared to 40 minutes without PPE. The results of this study indicated that the use inadequate PPE might pose thermoregulation risk to rural workers.     

Ergonomic factors and production target evaluation in eucalyptus timber harvesting operations in mountainous terrains

There are several forest operations involved in Eucalyptus timber harvesting. This study was carried out during brush-cutting; tree felling, bucking, delimbing, piling and manual extraction operations, with the following objectives: a) analyzing, ergonomically, two systems of brush-cutting: one manual and the other semi-mechanized, using two different machines; b) ergonomically evaluating three different brands of pruner machines used in delimbing felled trees. c) determining the feasible target of productivity as a function of ergonomic factors relevant to establish the time of resting pauses for workers in manual and semi-mechanized timber harvesting systems in mountainous terrain. Brush-cutting, either manual or semimechanized, is an activity carried out prior to timber harvesting. It is usually a hard work, with low productivity when compared with mechanized systems. Pruner machines have been used by forest companies, due to the great possibilities to improve productivity, quality and the health of workers. Ergonomics is a discipline that promotes the adequacy of work to the physical and mental characteristics of human beings, seeking to design production systems and products considering relevant aspects, including social, organizational and environmental factors. Companies should consider the ergonomic factor in the determination of daily worker production targets.     

Visualization of regulations to support design and quality control--a long-term study

The aim of the study was to visualize design regulations of furniture by means of interactive technology based on earlier studies and practical examples. The usage of the visualized regulations was evaluated on two occasions: at the start when the first set of regulations was presented, and after six years of usage of all regulations. The visualized regulations were the result of a design process involving experts and potential users in collaboration with IKEA of Sweden AB. The evaluations by the different users showed a very positive response to using visualized regulations. The participative approach, combining expertise in specific regulations with visualization of guidelines, resulted in clear presentations of important regulations, and great attitudes among the users. These kinds of visualizations have proved to be applicable in a variety of product areas at IKEA, with a potential for further dissemination. It is likely that the approaches to design and visualized regulations in this case study could function in other branches.     

Ergonomics and design: traffic sign and street name sign

This work proposes a design methodology using ergonomics and anthropometry concepts applied to traffic sign and street name sign projects. Initially, a literature revision on cognitive ergonomics and anthropometry is performed. Several authors and their design methodologies are analyzed and the aspects to be considered in projects of traffic and street name signs are selected and other specific aspects are proposed for the design methodology. A case study of the signs of "Street of Antiques" in Porto Alegre city is presented. To do that, interviews with the population are made to evaluate the current situation of signs. After that, a new sign proposal with virtual prototyping is done using the developed methodology. The results obtained with new interviews about the proposal show the user satisfaction and the importance of cognitive ergonomics to development of this type of urban furniture.     

Ergonomics analysis of the productive environment of fashion clothing firm in Belo Horizonte-MG

A company making women's clothing, located in Belo Horizonte, Minas Gerais was studied in its ergonomic aspects with regard to the layout. With this study it was possible to establish the best positioning of machines and jobs of employees. The analysis criteria used were: frequency of use, functional grouping, sequence of use, flow and intensity of preferred connections. An ideal arrangement in the workplace provides improved manufacturing quality and employee performance and consequently higher production yields.