Perturbaciones singulares de problemas de contorno para sistemas acoplados de ecuaciones en diferencias de segundo orden

En este articulo presentamos un método de perturbaciones singulares para problemas de contorno relacionados con sistemas acoplados de ecuaciones en diferencias de segundo orden con coeficientes variables involucrando un parámetro pequeño E. Estudiamos el comportamiento asintótico de la solución cuando E tiende a cero.In this paper singular perturbations for coupled second order boundary value difference systems with a small parameter E are treated. The asymptotic behavior of the solution when E approaches zero is studied.Peer Reviewe

Solución de problemas de contorno para ecuaciones en diferencias matriciales de segundo orden

En este articulo se estudian condiciones de existencia de solución de problemas de contorno para ecuaciones matriciales de segundo orden. Mediante la solución de una ecuación algebraica inatricial asociada al problema de contorno, obtenemos una expresión de la solución general del problema, computable en términos de los datos y sin aumentar la dimensión del problema.In this paper boundary value problems for second order matrix difference equations are considered. Existente conditions for the solutions of the problem as well as an explicit expression of the general solution of the problem, are given in terms of a solution of an algebraic matrix equation related to the problem. Our method provides an expression of the solutions of the problem avoiding the increase of the dimension of the problem.Peer Reviewe

Perturbaciones singulares de problemas de contorno para sistemas acoplados de ecuaciones en diferencias de segundo orden

En este articulo presentamos un método de perturbaciones singulares para problemas de contorno relacionados con sistemas acoplados de ecuaciones en diferencias de segundo orden con coeficientes variables involucrando un parámetro pequeño E. Estudiamos el comportamiento asintótico de la solución cuando E tiende a cero.In this paper singular perturbations for coupled second order boundary value difference systems with a small parameter E are treated. The asymptotic behavior of the solution when E approaches zero is studied.Peer Reviewe

Solución de problemas de contorno para ecuaciones en diferencias matriciales de segundo orden

En este articulo se estudian condiciones de existencia de solución de problemas de contorno para ecuaciones matriciales de segundo orden. Mediante la solución de una ecuación algebraica inatricial asociada al problema de contorno, obtenemos una expresión de la solución general del problema, computable en términos de los datos y sin aumentar la dimensión del problema.In this paper boundary value problems for second order matrix difference equations are considered. Existente conditions for the solutions of the problem as well as an explicit expression of the general solution of the problem, are given in terms of a solution of an algebraic matrix equation related to the problem. Our method provides an expression of the solutions of the problem avoiding the increase of the dimension of the problem.Peer Reviewe

Momentos clave en el aprendizaje de isometrías

El objetivo de este estudio es identificar ejemplos de momentos clave en el aprendizaje de isometrías de alumnos de 3o de ESO. Mostramos tres ejemplos de momentos clave y los analizamos para obtener nuevas características que ayuden a refinar la propia noción en construcción de momento clave

Construction and computation of variable coefficient sylvester differential problems

AbstractIn this paper, initial value problems for Sylvester differential equations X′(t) = A(t)X(t) + X(t)B(t) + F(t), with analytic matrix coefficients are considered. First, an exact series solution of the problem is obtained. Given a bounded domain Ω and an admissible error ϵ, a finite analytic-numerical series solution is constructed, so that the error with respect to the exact series solution is uniformly upper bounded by ϵ in Ω. An iterative procedure for the construction of the approximate solutions is included

Geometría y tecnología

Intentaremos ilustrar algunas investigaciones sobre el papel de la tecnología en la educación geométrica, que han ido apareciendo en distintos medios de difusión profesional, con la finalidad de que los resultados de dichas investigaciones puedan convencer al profesorado que los adopte en sus clases y mejore el aprendizaje de su alumnado

The evaluation of a highly specialist inpatient psychologist working with patients with high risk presentations in an acute mental health inpatient setting

Objective: To evaluate the function and impact of a highly specialist psychologist working with high risk patients in an acute mental health inpatient setting. The impact was examined on outcomes such as risk related incidents, re-admission, average length of stay, and use of restrictive practice. / Method: A mixed methods service evaluation of a pilot project was undertaken to examine the impact of the specialist psychologist role on these outcomes over a 17-month period. Demographic and clinical data was collected for 18 patients who were seen by the psychologist. Routinely collected clinical data examining risk incidents, re-admission rates, average length of stay, and use of restrictive practice, were also used to evaluate outcome across the evaluation period (at baseline and six-month follow-up). / Results: The specialist psychologist provided input to patients’ care and undertook a variety of direct and indirect work and training. Examination of descriptive routine clinical data indicated a slight reduction in risk related incidents, readmissions, and average length of stay after the introduction of the psychologist role, however these were not statistically significant. / Conclusion: These initial findings suggest the potential for outcome improvement, but further, more robust research is required to see if such a role can have a significant impact on outcomes

Comparison between conjugated linoleic acid and essential fatty acids in preventing oxidative stress in bovine mammary epithelial cells

Some in vitro and in vivo studies have demonstrated protective effects of conjugated linoleic acid (CLA) isomers against oxidative stress and lipid peroxidation. However, only a few and conflicting studies have been conducted showing the antioxidant potential of essential fatty acids. The objectives of the study were to compare the effects of CLA to other essential fatty acids on the thiol redox status of bovine mammary epithelia cells (BME-UV1) and their protective role against oxidative damage on the mammary gland by an in vitro study. The BME-UV1 cells were treated with complete medium containing 50 μM of cis-9,trans-11 CLA, trans-10,cis-12 CLA, α-linolenic acid, γ-linolenic acid, and linoleic acid. To assess the cellular antioxidant response, glutathione, NADPH, and γ-glutamyl-cysteine ligase activity were measured 48 h after addition of fatty acids (FA). Intracellular reactive oxygen species and malondialdehyde production were also assessed in cells supplemented with FA. Reactive oxygen species production after 3 h of H2O2 exposure was assessed to evaluate and to compare the potential protection of different FA against H2O2-induced oxidative stress. All FA treatments induced an intracellular GSH increase, matched by high concentrations of NADPH and an increase of γ-glutamyl-cysteine ligase activity. Cells supplemented with FA showed a reduction in intracellular malondialdehyde levels. In particular, CLA isomers and linoleic acid supplementation showed a better antioxidant cellular response against oxidative damage induced by H2O2 compared with other FA