La violencia simbólica en la escuela

La escuela como heredera de los Estados Nacionales ha practicado los ideales de libertad, fraternidad e igualdad, dando lugar a un proceso de igualación social y de pertenencia a un núcleo ético-mítico cultural común. Pero, el presente histórico en el que se instala la escuela actual no es Moderno sino Posmoderno o propio de una Modernidad tardía. La escuela de hoy afronta un desafío: o bien metaboliza los cambios del universo histórico-social de la realidad donde se constata el choque entre universos simbólicos, o bien realiza su práctica educativa sin tenerlos en cuenta. Para ello se postula en este trabajo la recuperación del sujeto a través de las subjetividades diferenciadas que intentan recuperar intereses, prácticas sociales, representaciones imaginarias a través de una dialéctica interna, considerando la pluralidad y diversidad de sentidos sociales, un sí mismo que resulte de la dialéctica de la conciencia y lo inconsciente por un lado y de la recuperación de las prácticas o intereses sociales por otro

Adaptive Time Step for Cardiac Myocyte Models

AbstractThe modeling of the electrical activity of the heart is of great medical and scientific interest as it provides a way to better understand the underlying biophysical phenomena, supports the development of new techniques for diagnoses and serves as a platform for drug tests. At cellular level, the electrical activity of cardiac myocytes may be simulated by solving a system of ordinary di_erential equations (ODEs) describing the electrical behavior of the cell membrane. Because the biophysical processes underlying this phenomenon are non-linear and change very rapidly, the ODE system is challenging to solve numerically. Furthermore, the implementation of these models is a hard task. This paper presents a tool to describe models using Ordinary Differential Equations. It is based on CellML standard and automatically generates C++ source-code, with numerical methods to solve the model's equations. The aim of this work is to present a numerical method with adaptive time step based on the Euler Method and Second Order Runge-Kutta method. The proposed method accelerated the execution and kept numerical errors under control. Preliminary results suggest this adaptive method is up to 25 times faster than the explicit Euler method with fixed time step

Development of a computational model of abscess formation

In some bacterial infections, the immune system cannot eliminate the invading pathogen. In these cases, the invading pathogen is successful in establishing a favorable environment to survive and persist in the host organism. For example, S. aureus bacteria survive in organ tissues employing a set of mechanisms that work in a coordinated and highly regulated way allowing: (1) efficient impairment of the immune response; and (2) protection from the immune cells and molecules. S. aureus secretes several proteins including coagulases and toxins that drive abscess formation and persistence. Unless staphylococcal abscesses are surgically drained and treated with antibiotics, disseminated infection and septicemia produce a lethal outcome. Within this context, this paper develops a simple mathematical model of abscess formation incorporating characteristics that we judge important for an abscess to be formed. Our aim is to build a mathematical model that reproduces some characteristics and behaviors that are observed in the process of abscess formation.Peer ReviewedPostprint (published version

Paralelização em um Ambiente de Memória Distribuída de um Simulador da Formação de Edemas no Coração

O objetivo deste trabalho é paralelizar um algoritmo que simula a formação de um edema no coração, usando para isso MPI, bem como analisar o seu desempenho em um cluster de computadores. Os resultados mostram que a versão paralela conseguiu reduzir o tempo de execução sequencial em até 14 vezes

Simulation of ectopic pacemakers in the heart: multiple ectopic beats generated by reentry inside fibrotic regions

The inclusion of nonconducting media, mimicking cardiac fibrosis, in two models of cardiac tissue produces the formation of ectopic beats. The fraction of nonconducting media in comparison with the fraction of healthy myocytes and the topological distribution of cells determines the probability of ectopic beat generation. First, a detailed subcellular microscopic model that accounts for the microstructure of the cardiac tissue is constructed and employed for the numerical simulation of action potential propagation. Next, an equivalent discrete model is implemented, which permits a faster integration of the equations. This discrete model is a simplified version of the microscopic model that maintains the distribution of connections between cells. Both models produce similar results when describing action potential propagation in homogeneous tissue; however, they slightly differ in the generation of ectopic beats in heterogeneous tissue. Nevertheless, both models present the generation of reentry inside fibrotic tissues. This kind of reentry restricted to microfibrosis regions can result in the formation of ectopic pacemakers, that is, regions that will generate a series of ectopic stimulus at a fast pacing rate. In turn, such activity has been related to trigger fibrillation in the atria and in the ventricles in clinical and animal studies.Peer ReviewedPostprint (published version

Parallel implementation of the aeh technique for the solution of plane multiphasic problems

The Asymptotic Expansion Homogenization (AEH) technique is used to estimate the effective properties of heterogeneous media with periodical microstructure. A considerable computational effort can be necessary even though the adopted models are quite simple. For this reason, parallelization is often necessary to achieve good performance. This work presents a first attempt to parallelize the AEH implementation code. Although the parallelization process is in a very early stage, the preliminary results show that the parallel version provides up to a 30% improvement in application speed. This work consists on a step towards a numerical tool for the analysis of more complex and three-dimensional periodic cells. The two-dimensional AEH was implemented in the C programming language for the future generalization to three-dimensional problems employing the available parallelization tools

Validation of a yellow fever vaccine model using data from primary vaccination in children and adults, re-vaccination and dose-response in adults and studies with immunocompromised individuals

Background: An effective yellow fever (YF) vaccine has been available since 1937. Nevertheless, questions regarding its use remain poorly understood, such as the ideal dose to confer immunity against the disease, the need for a booster dose, the optimal immunisation schedule for immunocompetent, immunosuppressed, and pediatric populations, among other issues. This work aims to demonstrate that computational tools can be used to simulate different scenarios regarding YF vaccination and the immune response of individuals to this vaccine, thus assisting the response of some of these open questions. Results: This work presents the computational results obtained by a mathematical model of the human immune response to vaccination against YF. Five scenarios were simulated: primovaccination in adults and children, booster dose in adult individuals, vaccination of individuals with autoimmune diseases under immunomodulatory therapy, and the immune response to different vaccine doses. Where data were available, the model was able to quantitatively replicate the levels of antibodies obtained experimentally. In addition, for those scenarios where data were not available, it was possible to qualitatively reproduce the immune response behaviours described in the literature. Conclusions: Our simulations show that the minimum dose to confer immunity against YF is half of the reference dose. The results also suggest that immunological immaturity in children limits the induction and persistence of long-lived plasma cells are related to the antibody decay observed experimentally. Finally, the decay observed in the antibody level after ten years suggests that a booster dose is necessary to keep immunity against YF