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

Discurso sobre la promoción de la igualdad de género en la campaña HeForShe en Brasil y México

The study analyzes the discourse of gender equality promotion in the HeForShe campaign in Brazil and Mexico, as well as its consequences, appropriations, and adaptations in the context of the COVID-19 pandemic. To this end, a bibliographic and content research of the UN-Women’s websites was performed and submitted to Critical Discourse Analysis (FAIRCLOUGH, 2001) through a three-dimensional analysis of the text, discursive practice, and social practice. Results indicate the similarity in the pursuit of men’s co-responsibility in gender equality.Este estudio se centra en el análisis del discurso sobre la promoción de la igualdad de género de la campaña ÉlPorElla en Brasil y México, así como sus consecuencias y adaptaciones en el contexto de la pandemia del covid-19. Se apoya en la investigación bibliográfica y de contenido de los sitios web de ONU Mujeres, utilizando el análisis crítico del discurso de Fairclough mediante la realización del análisis tridimensional del texto, la práctica discursiva y la práctica social. Los resultados indican la similitud en la búsqueda de la corresponsabilidad de los hombres en la igualdad de género.O estudo foca na análise do discurso da promoção da igualdade de gênero a partir da campanha HeForShe no Brasil e no México, seus desdobramentos, apropriações e adequações frente ao contexto da pandemia da covid-19. Tem suporte na pesquisa bibliográfica e conteúdo da ONU Mulheres, acionando a Análise Crítica do Discurso de Fairclough ao realizar uma análise tridimensional do texto e das práticas discursiva e social. Resultados indicam similaridade na busca da corresponsabilidade dos homens na equidade de gêneros

Dynamic Electric Dispatch for Wind Power Plants: A New Automatic Controller System Using Evolutionary Algorithms

In this paper, we use an evolutionary swarm intelligence approach to build an automatic electric dispatch controller for an offshore wind power plant (WPP). The optimal power flow (OPF) problem for this WPP is solved by the Canonical Differential Evolutionary Particle Swarm Optimization algorithm (C-DEEPSO). In this paper, C-DEEPSO works as a control system for reactive sources in energy production. The control operation takes place in a daily energy dispatch, scheduled into 15 min intervals and resulting in 96 operating test scenarios. As the nature of the optimization problem is dynamic, a fine-tuning of the initialization parameters of the optimization algorithm is performed at each dispatch interval. Therefore, a version of the C-DEEPSO algorithm has been built to automatically learn the best set of initialization parameters for each scenario. For this, we have coupled C-DEEPSO with the irace tool (an extension of the iterated F-race (I/F-Race)) by using inferential statistic techniques. The experiments carried out showed that the methodology employed here is robust and able to tackle this OPF-like modeling. Moreover, the methodology works as an automatic control system for a dynamic schedule operation

Dermatite atópica pediátrica: fisiopatologia e manejo terapêutico / Pediatric atopic dermatitis: pathophysiology and therapeutic management

A dermatite atópica (DA), conhecida também como eczema atópico, é uma condição inflamatória crônica recidivante que acomete o tecido cutâneo. No que tange às estatísticas gerais, a incidência de DA aumentou de 2 a 3 vezes nos países industrializados, afetando aproximadamente 15% a 20% das crianças e 1% a 3% dos adultos em todo o mundo. A DA, em termos fisiopatológicos, é uma afecção inflamatória crônica recidivante da pele, multifacetada, comumente associada a outras manifestações atópicas, como alergia alimentar, rinite alérgica e asma. O início da doença é mais comum aos 5 anos de idade, sendo o diagnóstico e o tratamento precoces essenciais para evitar complicações da DA e melhorar a qualidade de vida. Há muitas condições de pele que podem mimetizar essa doença, sendo possível até mesmo coexistirem e/ou agravarem a DA, que devem ser excluídas ao diagnosticá-la, tais como: dermatite seborreica, sarna, dermatite de contato, psoríase, linfoma cutâneo de células T, dentre outras afecções cutâneas. O tratamento da DA objetiva condutas multifatoriais, das quais dependem da associação de medidas não farmacológicas e farmacológicas, sendo prescrita de acordo com o grau da doença. É imprescindível que os portadores de DA sejam esclarecidos e aderentes às medidas não farmacológicas para prevenção de crises agudas. Nesse sentido, cita-se a necessidade do uso de hidratantes neutros em toda a pele após banhos diários, evitando cremes e sabonetes com produtos alérgenos, além de não se submeterem a extremos de calor, frio ou umidade. Associado a essas medidas, o tratamento farmacológico tem se mostrado muito eficaz em casos mais graves e recidivantes

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

Changes in the surface EMGs with changes in knee position.

<p>A short epoch of raw, surface EMGs is shown during plantar flexion contractions exerted with the knee fully extended (<i>a</i>) and the knee flexed at 90 deg (<i>b</i>). Only nine of the 15 channels in the array were positioned on skin regions covering the MG superficial aponeurosis. The RMS amplitude computed from EMGs detected by each of these nine channels is shown on the right side of each panel, with black circles denoting the channels providing RMS amplitudes greater than 70% of the maximum. Dashed lines indicate the barycentre coordinate computed for these channels.</p