Physiological modules for generating discrete and rhythmic movements: action identification by a dynamic recurrent neural network

In this study we employed a dynamic recurrent neural network (DRNN) in a novel fashion to reveal characteristics of control modules underlying the generation of muscle activations when drawing figures with the outstretched arm. We asked healthy human subjects to perform four different figure-eight movements in each of two workspaces (frontal plane and sagittal plane). We then trained a DRNN to predict the movement of the wrist from information in the EMG signals from seven different muscles. We trained different instances of the same network on a single movement direction, on all four movement directions in a single movement plane, or on all eight possible movement patterns and looked at the ability of the DRNN to generalize and predict movements for trials that were not included in the training set. Within a single movement plane, a DRNN trained on one movement direction was not able to predict movements of the hand for trials in the other three directions, but a DRNN trained simultaneously on all four movement directions could generalize across movement directions within the same plane. Similarly, the DRNN was able to reproduce the kinematics of the hand for both movement planes, but only if it was trained on examples performed in each one. As we will discuss, these results indicate that there are important dynamical constraints on the mapping of EMG to hand movement that depend on both the time sequence of the movement and on the anatomical constraints of the musculoskeletal system. In a second step, we injected EMG signals constructed from different synergies derived by the PCA in order to identify the mechanical significance of each of these components. From these results, one can surmise that discrete-rhythmic movements may be constructed from three different fundamental modules, one regulating the co-activation of all muscles over the time span of the movement and two others elliciting patterns of reciprocal activation operating in orthogonal directions.

Conselhos escolares nas escolas municipais de Duque de Caxias:tensões e perspectivas

A pesquisa objetivou investigar a formação dos conselheiros escolares nas Escolas Municipais de Duque de Caxias a partir da adesão do Município ao Programa Nacional de Fortalecimento dos Conselhos Escolares, coordenado pela Secretaria de Educação Básica do Ministério da Educação. Como o exame das ações do Programa e a identificação das mesmas no referido município perpassam pelos níveis macro, meso e micro do sistema educacional, a metodologia constituiu-se de pesquisa bibliográfica, análise de documentos, construção e retrospectiva histórica em torno do princípio da gestão democrática e dos conselhos escolares; de entrevistas no MEC, na Secretaria Municipal de Educação, com os diretores de duas escolas da rede de ensino e grupo focal com o Conselho Escolar, além da observação nas escolas. Tendo como base o princípio da democracia e a construção da prática democrática nas escolas, por meio da gestão, percebem-se os conselhos escolares como segmentos representativos, tanto da possibilidade de transformação como de manutenção dos processos que envolvem a transparência, a autonomia e a participação da comunidade escolar na gestão das escolas. A verificação das ações de um Programa governamental em escala nacional, envolvendo a colaboração entre os entes federados, permite desmistificar o distanciamento entre as esferas dos sistemas de ensino neste processo que envolve a capacitação dos conselheiros escolares. A pesquisa revelou que, embora o Município de Duque de Caxias tenha aderido ao Programa, ainda não promoveu ações no sentido de formação de seus Conselheiros Escolares. Não obstante, uma das escolas observadas no estudo promove uma dinâmica articulada, em seu funcionamento, no que se refere à participação da comunidade escolar e local na gestão da escola

Political Institutions, Technology and Growth: a dynamic panel approach

This paper investigates whether the effect of political institutions on sectoral economic performance is determined by the level of technological development of industries. Building on previous studies on the linkages among political institutions, technology and economic growth, we employ the dynamic panel Generalized Method of Moments (GMM) estimator for a sample of 4,134 country-industries from 61 industries and 89 countries over the 1990-2010 period. Our main findings suggest that changes of political institutions towards higher levels of democracy, political rights and civil liberties enhance economic growth in technologically developed industries. On the contrary, the same institutional changes might retard economic growth of those industries that are below a technological development threshold. Overall, these results give evidence of a technologically conditioned nature of political institutions to be growth-promoting.

Dynamic analysis of V-folded cavity for TEM00 operation of end-pumped solid-state laser

Based on graphic analysis design method of optical resonator, a simple design expression of V-folded cavity of end-pumped solid-state lasers with TEM00 operation is described, which satisfies two criterias of the resonator design. We give numerical simulation of spot size as a function of thermal focal length using this design approach whose advantages are validated experimentally.