This article describes a general item response theory model for personality items that allows the information provided by the item response times to be used to estimate the individual trait levels. ...The submodel describing the item response times is a modification of Thissen's log-linear model and is based on the distance-difficulty hypothesis in personality measurement. First, the procedures for fitting the model and assessing the goodness of fit are described. Second, the gain in the precision of estimating the individual trait levels when the information provided by the response times is used is assessed. Finally, all the developments in this article are illustrated by means of an empirical example.
Tungiasis is a neglected disease caused by the sand flea 'Tunga penetrans', and dogs are considered the main reservoirs in Brazil. This study aimed to identify the role of dogs as tungiasis ...dispersers and to investigate the presence of 'T. penetrans' in the soil of an endemic tourist area. Nine dogs infected by 'T. penetrans' were included in this study and received GPS collars to analyze their movement through the village. Duplicate sand samples were collected in different areas of the community. Those areas were classified as peridomicile (n = 110), open area (n = 110), beach (n = 50), and river (n = 58). The analysis of the points recorded by the collars showed that the dogs roamed throughout the community, potentially facilitating the spread of the disease. Samples contaminated with developmental forms of the parasite were found in the circulation area of three dogs. Adult fleas were found in 3/328 samples. These data emphasize that infected dogs' roaming can influence the fleas' dispersion in the soil. Statistically, none of the study variables had a significant correlation (p > 0.5) with the presence of 'T. penetrans' in the area analyzed. This study was the first to assess infected dogs' role as tungiasis propagators.
•Most visceral leishmaniasis cases reported in Brazil are from the northeast region, where the disease is strongly linked to poverty.•Children under 10 years old and males were more affected during ...2007-2017, and most cases were from urban areas.•Living in the Cerrado, Amazon or, to a lesser extent, Caatinga biomes was a risk factor for visceral leishmaniasis.•The epidemiological profile of visceral leishmaniasis cases remained unchanged during 2007-2017.•Data suggest that social improvements achieved in this region were not enough to mitigate the risk of this disease.
Most visceral leishmaniasis (VL) cases reported in Brazil are from the northeast region, where the disease is strongly linked to poverty. In spite of the still existing inequalities, many social improvements were achieved in the past decades in this region, but the possible impact of these improvements on VL remains poorly investigated. We conducted a cross-sectional study coupled with a spatial analysis of VL cases notified in northeastern Brazil from 2007 to 2017. In total, 21,703 cases were reported during this period, with an annual incidence of 3.6 cases per 100,000 inhabitants. Children under 10 years old and males were more affected, and most cases were from urban areas. Living in municipalities situated in the Cerrado, Amazon or, to a lesser extent, in the Caatinga biomes was a risk factor for VL. This study indicates that the epidemiological profile of VL patients remained unchanged in northeastern Brazil, suggesting that social improvements achieved in this region were not enough to mitigate the risk of this disease among the most affected populations.
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This article focuses on working and living conditions among local politicians in Sweden and their experiences with combining political work and family life. Applying a sociological perspective on ...representation, we first map the working and living conditions among politicians, with a specific focus on gender and age. We then examine experiences of work-family conflict and subjective well-being and investigate how these outcomes are related to gender, age, and working and living conditions. The main findings show significant gender differences in working and living conditions, with substantially higher levels of work-family conflict among young women politicians.
We study the conditions for positive recurrence and transience of multi-dimensional birth-and-death processes describing the evolution of a large class of stochastic systems, a typical example being ...the randomly varying number of flow-level transfers in a telecommunication wire-line or wireless network. First, using an associated deterministic dynamical system, we provide a generic method to construct a Lyapunov function when the drift is a smooth function on ℝ
N
. This approach gives an elementary and direct proof of ergodicity. We also provide instability conditions. Our main contribution consists of showing how discontinuous drifts change the nature of the stability conditions and of providing generic sufficient stability conditions having a simple geometric interpretation. These conditions turn out to be necessary (outside a negligible set of the parameter space) for piecewise constant drifts in dimension two.
This paper attempts to provide an optimum loading schedule of power generating units with the least cost by solving a unit commitment (UC) problem and to present good estimates of cost differences ...when UC problem is not applied. UC is a fundamental optimization problem of power generation systems which determines the optimum schedule of generating units which minimizes generation costs. However, for small power generation firms which are situated in developing countries, UC-based problems are poorly understood if not implemented and the scheduling of generating units is based on some methodologies which may provide results that are not optimal. Thus, a case study in a small power generation firm in central Philippines is carried out to elucidate these objectives. The case requires a solution of the mixed-integer nonlinear programming (MINLP) problem. Results show that the proposed UC-based problem yields optimal costs and the cost disparity from the current scheduling scheme is approximately at 27% which may be considered as potential cost savings. This shows that UC-based problem provides a reliable platform in achieving minimal generation costs. These results are significant to decision-makers particularly in small power generation firms and to engineering practitioners in the Philippines and in some developing countries as these provide an overview of the disparity of cost figures of not implementing UC.
The aim of the study was to examine the factor structure and psychometric properties of the Spanish version of the Mini-Mental Adjustment to Cancer Scale (Mini-MAC) in a large sample of patients with ...non-metastatic, resected cancer.
Prospective, observational, multicenter study for which 914 patients were recruited from 15 Spanish hospitals. Exploratory and confirmatory factor analyses, validity and reliability analyses were conducted.
Factor-analytic results indicated a 4-factor structure of the Spanish version of the Mini-MAC. Three subscales have psychometric properties similar to those of Helplessness, Anxious preoccupation, and Cognitive avoidance of the original the Mini-MAC. The Fighting spirit and the Fatalism subscales were combined on the Positive attitude scale. The four factor-derived scale scores exhibited acceptable accuracy for individual measurement purposes, as well as stability over time in test-retest assessments at 6 months. Validity assessments found meaningful relations between the derived scale scores, and Brief Symptom Inventory depression and anxiety scores and Functional Assessment of Chronic Illness Therapy spiritual well-being scores.
The Spanish version of the Mini-MAC provides reliable and valid measures for patients with non-metastatic, resected cancer, and results corroborate the instrument’s cross-cultural validity.
El objetivo de este estudio fue analizar las propiedades psicométricas de la versión Española del Mini-Mental Adjustment to Cancer Scale (Mini-MAC) en pacientes con cáncer resecado, no metastásico.
Estudio multicéntrico, prospectivo y observacional con 914 pacientes reclutados en 15 hospitales de España. Se llevaron a cabo análisis factorial exploratorio y confirmatorio, así como análisis de la validez y fiabilidad de las puntuaciones de la escala.
Los resultados de los análisis factoriales sugieren que la estructura más apropiada para la versión española del Mini-MAC es la de cuatro factores. Tres subescalas derivadas de esta estructura tienen propiedades psicométricas similares a la escala original: Desesperanza, Preocupación ansiosa y Evitación cognitiva. Las subescalas Espíritu de lucha y Fatalismo se combinaron en la escala Actitud positiva. Las puntuaciones en las cuatro escalas mostraron una fiabilidad aceptable para su utilización en la evaluación individual, así como estabilidad a lo largo del tiempo en evaluaciones test-retest a los seis meses. Se obtuvieron evidencias de validez en forma de relaciones significativas con las escalas de ansiedad y depresión del BSI, y de bienestar espiritual del FACIT.
La versión Española del Mini-MAC proporciona puntuaciones fiables y válidas para evaluar las estrategias de afrontamiento en pacientes con cáncer y los resultados añaden evidencia a favor de la validez transcultural del instrumento.
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