Student's academic efficacy or Inefficacy? an example on how to evaluate the psychometric properties of a measuring instrument and evaluate the effects of item wording

This study evaluated the effect of item inversion on the construct validity and reliability of psychometric scales and proposed a theoretical framework for the evaluation of the psychometric properties of data gathered with psychometric instruments. To this propose, we used the Maslach Burnout Inventory, which is the most used psychometric inventory to measure burnout in different professional context (Students, Teachers, Police, Doctors, Nurses, etc…). The version of the MBI used was the MBI-Student Survey (MBI-SS). This inventory is composed of three key dimensions: Exhaustion, Cynicism and Professional Efficacy. The two first dimensions—which have positive formulated items—are moderate to strong positive correlated, and show moderate to strong negative correlations with the 3rd dimension—which has negative formulated items. We tested the hypothesis that, in college students, formulating the 3rd dimension of burnout as Inefficacy (reverting the negatively worded items in the Efficacy dimension) improves the correlation of the 3rd dimension with the other two dimensions, improves its internal consistency, and the overall MBI-SS’ construct validity and reliability. Confirmatory factor analysis results, estimated by Maximum Likelihood, revealed adequate factorial fit for both forms of the MBI-SS (with Efficacy) vs. the MBI-SSi (with Inefficacy). Also both forms showed adequate convergent and discriminant related validity. However, reliability and convergent validity were higher for the MBI-SSi. There were also stronger (positive) correlations between the 3 factors in MBI-SSi than the ones observed in MBI-SS. Results show that positively rewording of the 3rd dimension of the MBI-SS improves its validity and reliability. We therefore propose that the 3rd dimension of the MBI-SS should be named Professional Inefficacy and its items should be positively worded.

Fetal kidney programming by severe food restriction: effects on structure, hormonal receptor expression and urinary sodium excretion in rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Deriving vegetation indices for phenology analysis using genetic programming

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Short-term expansion planning of radial electrical distribution systems using mixed-integer linear programming

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The use of nonlinear programming as a tool for maximum profit feed formulation of broilers

The purpose of this study was to compare linear and nonlinear programming models for feed formulation, for maximum profit, considering the real variation in the prices of the corn, soybean meal and broilers during the period from January of 2008 to October of 2009, in the São Paulo State, Brazil. For the nonlinear formulation model, it was considered the following scenarios of prices: a) the minimum broiler price and the maximum prices of the corn and soybean meal during the period, b) the mean prices of the broiler, corn and soybean meal in the period and c) the maximum broiler price and the minimum prices of the corn and soybean meal, in the considered period; while for the linear formulation model, it was considered just the prices of the corn and the soybean. It was used the Practical Program for Feed Formulation 2.0 for the diets establishment. A total of 300 Cobb male chicks were randomly assigned to the 4 dietary treatments with 5 replicate pens of 15 chicks each. The birds were fed with a starter diet until 21 d and a grower diet from 22 to 42 d of age, and they had ad libitum access to feed and water, on floor with wood shavings as litter. The broilers were raised in an environmentally-controlled house. Body weight, body weight gain, feed intake, feed conversion ratio and profitability (related to the prices variation of the broilers and ingredients) were obtained at 42 d of age. It was found that the broilers fed with the diet formulated with the linear model presented the lowest feed intake and feed conversion ratio as compared with the broilers fed with diets from nonlinear formulation models. There were no significant differences in body weight and body weight gain among the treatments. Nevertheless, the profitabilities of the diets from the nonlinear model were significantly higher than that one from the linear formulation model, when the corn and soybean meal prices were near or below their average values for the studied period, for any broiler chicken price.

Profile of the production engineer student at a school of engineering in Brazil: academic and professional trajectories and tendencies

The objective of this paper is to introduce a study on the academic trajectory and professional profile of production engineers who graduated in a traditional and renowned Brazilian University (School of Engineering at Bauru – FEB). The study was conducted with the first three classes of undergraduates in the production engineering program at FEB/UNESP. A 50% response rate was obtained and with the data collected it was possible to characterize the professional profile of the students and outline their academic trajectory. According to the sample, the main result is that the curricular grid is the main criterion of similarity in student education, thus, the focus on program improvements should focus on the curricular grid. Tendencies are also pointed out to guide the search for improvements in the academic trajectory of production engineering students.