Aspectos filosóficos do conto "Conversa de Bois" em Sagarana de Guimarães Rosa

This paper explores some philosophical questions regarding the tale “Conversation Among Oxen”, from Sagarana, of João Guimarães Rosa. Two philosophical questions are addressed. The first regards the carter Agenor Soronho ethics; the second is related to the narrative of Rodapião ox, which refers to knowledge theory and ontology. The unfortunate destiny of both characters, as well as some passages of the author’s correspondence, points towards a criticism against Cartesian rationalism and to utilitarian ethics. Simultaneously, the tale renders classical philosophy and literature questions into the backcountry scenario.Este trabalho explora aspectos de natureza filosófica do conto “Conversa de Bois”, do livro Sagarana, de Guimarães Rosa. Foram identificadas duas questões filosóficas que perpassam o conto. Uma delas está relacionada à filosofia prática, que é o problema ético do carreiro Agenor Soronho. A outra diz respeito à teoria do conhecimento, passando pela ontologia, na estória do boi Rodapião. O infeliz destino dos dois personagens, bem como algumas passagens da correspondência rosiana, apontam a uma crítica ao racionalismo cartesiano e ao utilitarismo ético. Ao mesmo tempo, o conto transpõe diversas questões recorrentes da filosofia e da literatura clássicas para o ambiente sertanejo

Variations in the spatial distribution of the amplitude of surface electromyograms are unlikely explained by changes in the length of medial gastrocnemius fibres with knee joint angle

This study investigates whether knee position affects the amplitude distribution of surface electromyogram (EMG) in the medial gastrocnemius (MG) muscle. Of further concern is understanding whether knee-induced changes in EMG amplitude distribution are associated with regional changes in MG fibre length. Fifteen surface EMGs were acquired proximo-distally from the MG muscle while 22 (13 male) healthy participants (age range: 23-47 years) exerted isometric plantar flexion at 60% of their maximal effort, with knee fully extended and at 90 degrees flexion. The number of channels providing EMGs with greatest amplitude, their relative proximo-distal position and the EMG amplitude averaged over channels were considered to characterise changes in myoelectric activity with knee position. From ultrasound images, collected at rest, fibre length, pennation angle and fat thickness were computed for MG proximo-distal regions. Surface EMGs detected with knee flexed were on average five times smaller than those collected during knee extended. However, during knee flexed, relatively larger EMGs were detected by a dramatically greater number of channels, centred at the MG more proximal regions. Variation in knee position at rest did not affect the proximo-distal values obtained for MG fibre length, pennation angle and fat thickness. Our main findings revealed that, with knee flexion: i) there is a redistribution of activity within the whole MG muscle; ii) EMGs detected locally unlikely suffice to characterise the changes in the neural drive to MG during isometric contractions at knee fully extended and 90 degrees flexed positions; iii) sources other than fibre length may substantially contribute to determining the net, MG activation

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research has been devoted to the development of legged robots able to reach gait patterns more or less similar to human beings. Towards this objective, many scientific papers have been published, focusin

Regional changes in gastrocnemius architecture with knee position.

<p>Mean values and standard deviation (whiskers) are shown for the fat thickness (panel <i>a</i>), the MG fibre length (panel <i>b</i>), and their pennation angle (panel <i>c</i>). These values were obtained from panoramic ultrasound images (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126888#pone.0126888.g005" target="_blank">Fig 5</a>), separately for the proximal (dark, shaded bars) and distal (light, shaded bars) muscle regions. Asterisks denote statistical differences at <i>P</i> < 0.05.</p

Displacement of innervation zone with knee flexion.

<p>Short epochs (250 ms) of the 15 single-differential EMGs collected from a single participant are shown. Signals in the left and right panels were obtained during knee extended and knee flexed positions, respectively. Propagating potentials are observed in the most distal channels, which were covering the most distal MG fibres. The channel in the array positioned most closely to the innervation zone of the muscle distal fibres is indicated with grey, shaded rectangles. Note the innervation zone moved distally from knee extended to knee flexed position.</p

Electrodes positioning and gastrocnemius architecture.

<p>A schematic illustration of the relative position of surface electrodes on the medial gastrocnemius (MG) muscle is shown. The parameters considered to characterise architectural differences between the MG proximal and distal regions are further illustrated in the figure; pennation angle, fibre length and fat thickness. Proximal and distal MG regions were respectively defined as the proximal and distal half of the distance between the distal extremity of the superficial aponeurosis and the most proximal electrode. Only the surface EMGs detected by electrodes positioned in correspondence of the superficial aponeurosis were retained for analysis.</p