José Contreras | ESPOL (Escuela Superior Politécnica del Litoral) (original) (raw)
Papers by José Contreras
Personality and Individual Differences, 2001
A set of two dynamic tests were developed for measuring spatial orientation and spatial visualiza... more A set of two dynamic tests were developed for measuring spatial orientation and spatial visualization (SODT and SVDT). These dynamic spatial tests were designed for computer administration. A printed battery including reasoning and spatial tests was also administered to a sample of 602 university graduates, 300 females (mean age=27.17) and 302 males (mean age=28.41). The participants were applicants for an air trac control training program. Therefore, they were highly motivated to do their best. The present study is based on three main questions: (1) do the new dynamic spatial tests measure the same ability irrespective of sex?; (2) are performance dierences between the sexes negligible for spatial tasks that closely resemble`real' spatial orientation activities?; and (3) is type of education related to dynamic spatial performance? (to our knowledge, a question not directly addressed in the previous literature). The ®ndings suggest that: (1) the factor structure is the same for both sexes; (2) males have an overall higher dynamic spatial performance than females; and (3) neither males' nor females' type of education makes any dierence to their dynamic spatial performance. When males and females have the same type of education, dynamic spatial performance is still higher in males. #
Scripta Materialia, 2004
Significant grain refinement can be achieved using a simple processing method such as large strai... more Significant grain refinement can be achieved using a simple processing method such as large strain rolling (LSR) in an AM60 alloy. The stabilization during rolling of a double-peak (slightly o -basal) texture is attributed to increasing non-basal <c+a> slip activity. There is evidence that grain refinement takes place via continuous dynamic recrystallization (CDRX)
International Journal of Cardiology, 1990
data concerning the great arterial trunks and their branches. Int J Cardiol 1990;29:127-139. In a... more data concerning the great arterial trunks and their branches. Int J Cardiol 1990;29:127-139. In a total of 4% fetuses and newborns ranging in body weight from 60 to 5000 g, we performed a morphometric study of the vasctdar complex, that is the orifices of the great arterial trunks, ascending aorta, aortic arch, vessels branching from the aortic arch, the aortic isthmus, descending aorta, pulmonary trunk, orifices of the pulmonary arteries and arterial duct. In all, 17 different parameters were measured in each specimen, using several new parameters in addition to the measurements classically used in the aortic isthmus, arterial duct and pulmonary trunk. Anatomogeometric models of these structures were developed, and stereometric formulas used to calculate the real volumes of the aortic isthmus, arterial duct and pulmonary trunk. The variations in the correlations between two measurable characteristics, that is, body weight and each of the morphometric parameters were analyzed, and the minimum, normal and maximum patterns of normality for each parameter were obtained with regression equations. The results show that the volume of the aortic isthmus increases by 0.03 ml for each millilitre increase in left ventricular volume. The isthmic volume increases by 0.32 ml for each millilitre increase in volume of the arterial duct and the volume of the pulmonary trunk increases by 6.4 ml for each increase of 1 millilitre in the volume of the aortic isthmus. The inner circumference of the aortic isthmus is greater than that of the arterial duct, whereas the former vessel is always shorter than the latter. We believe that these morphological data, when appropriately interpreted, have immediate clinical and surgical applications in the treatment of fetal and perinatal cardiovascular disorders.
International Journal of Cardiology, 1987
A total of 367 human fetuses and newborn subjects weighing from 60 to 5000 g provided the materia... more A total of 367 human fetuses and newborn subjects weighing from 60 to 5000 g provided the material for a morphometric study of the heart. A total of 17 interventricular parameters were measured in each specimen, one of the parameters representing an innovation with regard to the classically used set of measurements. A new anatomo-geometric configuration is described for each ventricle along with a new component for the left ventricular outflow tract, designated as the aortic outflow tract. The appropriate stereometric formulas were used to calculate real ventricular volumes rather than the previously studied volumetric indices. Additionally, correlation indices were calculated for ventricular wall thickness as well as the circumferences and diameters of the atrioventricular and arterial valves. The results show that, in fetuses of up to 2700 g in body weight, ventricular wall thickness is greater in the right than in the left ventricle, although the opposite is true in fetuses weighing above 2700 g. Throughout the range of weights studied, ventricular volume was greater in the left than in the right chamber. Tricuspid and pulmonary valve circumference and diameter were consistently greater than in the mitral and aortic valves, respectively. We believe the new morphometric data and their innovative interpretation to have immediate applications in both the morphological and functional areas of cardiology.
El objetivo que deseamos alcanzar en esta práctica es poder analizar y observar el desarrollo y l... more El objetivo que deseamos alcanzar en esta práctica es poder analizar y observar el desarrollo y las fases de crecimiento de una semilla, en nuestro caso el frejol.
Personality and Individual Differences, 2001
A set of two dynamic tests were developed for measuring spatial orientation and spatial visualiza... more A set of two dynamic tests were developed for measuring spatial orientation and spatial visualization (SODT and SVDT). These dynamic spatial tests were designed for computer administration. A printed battery including reasoning and spatial tests was also administered to a sample of 602 university graduates, 300 females (mean age=27.17) and 302 males (mean age=28.41). The participants were applicants for an air trac control training program. Therefore, they were highly motivated to do their best. The present study is based on three main questions: (1) do the new dynamic spatial tests measure the same ability irrespective of sex?; (2) are performance dierences between the sexes negligible for spatial tasks that closely resemble`real' spatial orientation activities?; and (3) is type of education related to dynamic spatial performance? (to our knowledge, a question not directly addressed in the previous literature). The ®ndings suggest that: (1) the factor structure is the same for both sexes; (2) males have an overall higher dynamic spatial performance than females; and (3) neither males' nor females' type of education makes any dierence to their dynamic spatial performance. When males and females have the same type of education, dynamic spatial performance is still higher in males. #
Scripta Materialia, 2004
Significant grain refinement can be achieved using a simple processing method such as large strai... more Significant grain refinement can be achieved using a simple processing method such as large strain rolling (LSR) in an AM60 alloy. The stabilization during rolling of a double-peak (slightly o -basal) texture is attributed to increasing non-basal <c+a> slip activity. There is evidence that grain refinement takes place via continuous dynamic recrystallization (CDRX)
International Journal of Cardiology, 1990
data concerning the great arterial trunks and their branches. Int J Cardiol 1990;29:127-139. In a... more data concerning the great arterial trunks and their branches. Int J Cardiol 1990;29:127-139. In a total of 4% fetuses and newborns ranging in body weight from 60 to 5000 g, we performed a morphometric study of the vasctdar complex, that is the orifices of the great arterial trunks, ascending aorta, aortic arch, vessels branching from the aortic arch, the aortic isthmus, descending aorta, pulmonary trunk, orifices of the pulmonary arteries and arterial duct. In all, 17 different parameters were measured in each specimen, using several new parameters in addition to the measurements classically used in the aortic isthmus, arterial duct and pulmonary trunk. Anatomogeometric models of these structures were developed, and stereometric formulas used to calculate the real volumes of the aortic isthmus, arterial duct and pulmonary trunk. The variations in the correlations between two measurable characteristics, that is, body weight and each of the morphometric parameters were analyzed, and the minimum, normal and maximum patterns of normality for each parameter were obtained with regression equations. The results show that the volume of the aortic isthmus increases by 0.03 ml for each millilitre increase in left ventricular volume. The isthmic volume increases by 0.32 ml for each millilitre increase in volume of the arterial duct and the volume of the pulmonary trunk increases by 6.4 ml for each increase of 1 millilitre in the volume of the aortic isthmus. The inner circumference of the aortic isthmus is greater than that of the arterial duct, whereas the former vessel is always shorter than the latter. We believe that these morphological data, when appropriately interpreted, have immediate clinical and surgical applications in the treatment of fetal and perinatal cardiovascular disorders.
International Journal of Cardiology, 1987
A total of 367 human fetuses and newborn subjects weighing from 60 to 5000 g provided the materia... more A total of 367 human fetuses and newborn subjects weighing from 60 to 5000 g provided the material for a morphometric study of the heart. A total of 17 interventricular parameters were measured in each specimen, one of the parameters representing an innovation with regard to the classically used set of measurements. A new anatomo-geometric configuration is described for each ventricle along with a new component for the left ventricular outflow tract, designated as the aortic outflow tract. The appropriate stereometric formulas were used to calculate real ventricular volumes rather than the previously studied volumetric indices. Additionally, correlation indices were calculated for ventricular wall thickness as well as the circumferences and diameters of the atrioventricular and arterial valves. The results show that, in fetuses of up to 2700 g in body weight, ventricular wall thickness is greater in the right than in the left ventricle, although the opposite is true in fetuses weighing above 2700 g. Throughout the range of weights studied, ventricular volume was greater in the left than in the right chamber. Tricuspid and pulmonary valve circumference and diameter were consistently greater than in the mitral and aortic valves, respectively. We believe the new morphometric data and their innovative interpretation to have immediate applications in both the morphological and functional areas of cardiology.
El objetivo que deseamos alcanzar en esta práctica es poder analizar y observar el desarrollo y l... more El objetivo que deseamos alcanzar en esta práctica es poder analizar y observar el desarrollo y las fases de crecimiento de una semilla, en nuestro caso el frejol.