L'utilisation d'outils en tant qu'aide à la nutrition a évolué indépendamment dans plusieurs groupes taxonomiques. Parmi ces outils, certaines constructions animales sont destinées à piéger les proies (e.g. les toiles d'araignées). Le fonctionnement physique de ces pièges reste largement inconnu à ce jour. Les pièges de type « toile » sont particulièrement difficiles à analyser car leurs architectures et leurs propriétés mécaniques sont complexes. Le fourmilion utilise du sable sec pour creuser un piège afin de capturer des fourmis. La proie est amenée jusqu'au prédateur sans effort de sa part dans les conditions optimales. Ce piège offre une architecture simple en forme de cratère, modèle idéal pour la compréhension physique du fonctionnement d'un piège. Une architecture optimale théorique est définie comme un cratère parfaitement conique, mais avec une pente inférieure à ce qu'autorise la physique du sable, afin d'éviter des avalanches inutiles. Un système de balayage et de modélisation tridimensionnelle a permis une reconstitution fine de l'architecture des pièges. Grâce à cet appareillage, il a été montré que le piège construit par le fourmilion était proche de l'optimalité, mais qu'une dégradation architecturale suscitait un comportement d'attaque et un coût de prédation : des jets de sable, pour déstabiliser les fourmis s'échappant du piège, et des morsures. Un stimulus artificiel modélisant les pas d'une fourmi sur le sable à aboutit à l'élaboration d'un biotest. Il a prouvé que le fourmilion utilise l'information mécanique propagée dans le sable pour orienter morsures et jets de sable. L'exploitation des particularités physiques du milieu granulaire « sable » garantit ainsi l'efficacité de la prédation. Ces résultats sont discutés dans une perspective d'écologie évolutive.

The Nashville Civil Rights Movement was one of the most dynamic local movements of the early 1960s, producing the most capable student leaders of the period 1960 to 1965. Despite such a feat, the historical record has largely overlooked this phenomenon. What circumstances allowed Nashville to produce such a dynamic movement whose youth leadership of John Lewis, Diane Nash, Bernard LaFayette, and James Bevel had no parallel? How was this small cadre able to influence movement developments on local and a national level? In order to address these critical research questions, standard historical methods of inquiry will be employed. These include the use of secondary sources, primarily Civil Rights Movement histories and memoirs, scholarly articles, and dissertations and theses. The primary sources used include public lectures, articles from various periodicals, extant interviews, numerous manuscript collections, and a variety of audio and video recordings. No original interviews were conducted because of the availability of extensive high quality interviews. This dissertation will demonstrate that the Nashville Movement evolved out of the formation of independent Black churches and college that over time became the primary sites of resistance to racial discrimination, starting in the Nineteenth Century. By the late 1950s, Nashville’s Black college attracted the students who became the driving force of a local movement that quickly established itself at the forefront of the Civil Rights Movement. Nashville’s forefront status was due to an intentional leadership training program based upon nonviolence. As a result of the training, leaders had a profound impact upon nearly every major movement development up to 1965, including the sit-ins, the Freedom Rides, the March on Washington, the birth of SNCC, the emergence of Black Power, the direction of the SCLC after 1962, the thinking of Dr. Martin Luther King, Jr., the Birmingham campaign, and the Selma voting rights campaign. In addition, the Nashville activists helped eliminate fear as an obstacle to Black freedom. These activists also revealed new relationship dynamics between students and adults and merged nonviolent direct action with voter registration, a combination considered incompatible.

Les résultats de récentes études supportent l’idée que la perception de la force aurait un rôle important dans la réalisation des tâches fonctionnelles telles que le passage assis à debout (PAD). Cependant, très peu d’études se sont attardées à quantifier la précision avec laquelle les individus en santé sont capables de percevoir la force musculaire. De plus, aucune étude n’a évalué la perception de la distribution du poids lors du PAD chez la clientèle saine. L’objectif principal était de recueillir des données sur la capacité des individus en santé, jeunes et âgés, à percevoir la force musculaire lors d’une contraction statique des extenseurs du genou et à percevoir la distribution du poids (DP) lorsqu’ils réalisent le passage assis à debout. Cette étude a été effectuée auprès de 31 individus, divisés en deux groupes d’âge (< 50 ans et > 60 ans). Les résultats du premier objectif visant à quantifier les erreurs de perception de la force lors d’une contraction statique des extenseurs du genou ont démontré que les erreurs absolues et brutes sont plus élevées pour les niveaux de force supérieurs à 50 % CVM et que les erreurs brutes sont plus importantes chez les jeunes pour les hauts niveaux de force. Les résultats du second objectif visant à évaluer l’effet de différentes références sensorimotrices sur les erreurs de perception de la force musculaire ont montré qu’une référence à 50 % CVM préalablement montrée au participant et qu’une contraction simultanée des muscles de la préhension de la main diminuent les erreurs brutes et absolues de perception pour le niveau de force 70%. Les résultats du troisième objectif visant à quantifier les erreurs de perception de la DP lors du PAD ont démontré que les sujets jeunes et âgés ont une bonne capacité à percevoir leur DP avec des erreurs absolues et brutes variant respectivement entre 2,9 % et 9,4 % et entre -5,7 % et 5,7 % et des coefficients de corrélations intra-classes supérieurs à 0,75 entre la DP produite et celle perçue. Les résultats contribuent à approfondir les connaissances relatives à la perception de la force et de la DP chez les individus en santé. Ces données pourront servir à titre comparatif lors d’études menées auprès des patients hémiparétiques afin d’évaluer s’ils ont des problèmes perceptifs pouvant expliquer l’asymétrie récurrente qu’ils présentent dans leurs tâches fonctionnelles. / Results of recent studies support the idea that perception of force would have an important role in performing functional tasks such as sit-to-stand (STS). However, very few studies have focused on the quantification of the accuracy with which healthy individuals are able to perceive muscular force. Furthermore, no study has assessed the perception of weight-bearing distribution during the STS in healthy individuals. The purpose of this study was to provide evidence on the capacity to perceive muscular force and weight-bearing distribution in simple and complex tasks in healthy individuals. This study was conducted with 31 individuals, divided into two main age groups (<50 years > 60 years). Its first objective was to quantify the errors in perception of force during a static contraction of knee extensors and to compare these errors between young and elderly groups. Results showed that the absolute and raw errors are greater for force levels higher than 50% of maximum voluntary contraction (MVC) and that raw errors are greater in young participants for high force levels. This study’s second objective was to assess the effect of different sensorimotor references on the magnitude of errors of force perception. The results showed that a reference of 50% MVC presented to the participant beforehand or a simultaneous contraction of hand grip muscles reduced the raw and absolute errors of perception at the level of 70% MVC. A third objective was to quantify the errors of perception of weight-bearing distribution during STS and to measure the effect of age on these errors. The results showed that younger and elderly participants have an ability to perceive their weight-bearing distribution with absolute and raw errors varying respectively from 2.9% to 9.4% and from -5.7% to 5.7%. The intra-class correlation coefficient was higher than 0.75 between the weight-bearing distribution produced and that perceived during STS. The results contribute to extend knowledge about perception of force and weight bearing distribution in young and elderly healthy individuals. This data will be used for comparison in studies conducted with hemiparetic individuals in order to assess if the latter have perceptual problems which may explain the recurrent asymmetry they present in functional tasks.

<p>Diss. (sammanfattning) Umeå : Umeå universitet, 1995, härtill 6 uppsatser.</p> / digitalisering@umu

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Master thesis discusses the growing need of electric energy storage and its effectivity and capacity. It describes an overview of possible technologies with their advantages and disadvantages. Greater attention is paid to the storage of energy in gas, so-called Power to Gas, which combines the electrolytic production of hydrogen from water and the Sabatier reaction to produce synthetic methane. This technology is introduced in the so-called SIT Brno cycle of Siemens Industrial Turbomachinery company. The main part of the thesis is focused on the description of this cycle and on the calculation of the steam-gas turbine (high-pressure and low pressure module). This thesis describes the methodology of turbine calculation and the composition of the steam gas mixture after combustion of methane. The carbon dioxide formed by combustion in the steam-gas mixture generator was replaced by steam. Part of the diploma thesis are drawings of cross-section of individual turbine modules.

Orientador: Lilian Teresa Bucken Gobbi / Resumo: O treinamento resistido tem sido estudado no contexto do envelhecimento e da doença de Parkinson, mas há falta de exploração das características deste tipo de treinamento que contribuem na melhora da locomoção e da funcionalidade. A pergunta central desta tese é: Quais características do treinamento resistido no contexto do envelhecimento saudável e da doença de Parkinson permitem potenciar seus efeitos no desempenho locomotor? Para responder este questionamento foram desenvolvidos dois estudos. ESTUDO 1. Novos modelos de periodização do treinamento, como a periodização ondulatória e a periodização inversa, têm sido desenvolvidos, mas não há evidências sobre as vantagens da periodização ondulatória quando comparada com a periodização linear em idosos. Por outro lado, a periodização inversa não tem sido testada em idosos. Assim, o objetivo do presente estudo foi analisar os efeitos de dois treinamentos de força com periodizações diferentes na locomoção de idosos saudáveis. Participaram 69 idosos (70,23±6,81 anos, 72,58±5,51 Kg, 162,26±5,92 cm), cognitivamente preservados (27,40±1,20 pontos Mini-Exame de Estado Mental) e fisicamente ativos (12,64±3,15 pontos Baecke). A amostra foi distribuída em três grupos, grupo de treinamento de força com periodização inversa ondulatória (GPIO n=25), grupo de treinamento de força com periodização linear (GPL n=25) e grupo controle (GC n=19). Foram realizadas 20 semanas de treinamento resistido, 2 dias na semana, mais 1 dia de treinamento loc... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Resistance training has been studied in the context of aging and Parkinson's disease, but there is a lack of exploration of the characteristics of this type of training that contribute to the improvement of locomotion and functionality. The central question of this thesis is: What characteristics of resistance training in the context of healthy aging and Parkinson's disease allow to enhance its effects on locomotor performance? To answer this question two studies were developed. STUDY 1. New models of training periodization, such as undulating periodization and inverse periodization, have been developed, but there is no evidence about the advantages of wave periodization compared to linear periodization in the elderly. On the other hand, inverse periodization has not been tested in the elderly. Thus, the aim of the present study was to analyze the effects of two strength training with different periodizations on the mobility of healthy elderly. Participants were 69 elderly (70.23 ± 6.81 years, 72.58 ± 5.51 Kg, 162.26 ± 5.92 cm), cognitively preserved (27.40 ± 1.20 points Mini Mental State Examination) and physically active (12.64 ± 3.15 Baecke points). The sample was divided into three groups, strength training group with inverse undulating periodization (IUPG n = 25), force training group with linear periodization (LPG n = 25) and control group (CG n = 19). We performed 20 weeks of resistance training, 2 days a week, plus 1 day of locomotor training. GPIO performed a decreas... (Complete abstract click electronic access below) / Doutor

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Title: The effect of chosen manual techniques on static and dynamic postural stability in physiotherapy students. Aims: The main aim of this study is to assess the effect of chosen manual techniques on participants' static and dynamic postural stability. Summary: The study was done from May to December 2019. A total of 100 subjects aged 19-38years took part in the study. Participants were randomly divided into two groups - experimental and control. Postural stability was measured by the following tests: Star Excursion Balance test, Unipedal Stance test, Timed Up and Go test and Sit to Stand test. These standardised measurements were taken before intervention, after intervention and a week from intervention. Experimental group undertook the intervention by manual techniques, which took 20 minutes. Outcomes were written into recording sheets. Final data were processed using Microsoft Excel 2013, IBM SPSS Statistics V26 and TIBCO Statistica 13.3.0. To calculate differences, the following statistical methods were used: Shapiro-Wilk test, independent T-test and Mann-Whitney U test. To measure effect size, Cohen's d was used. The level of statistical significance was determined to α = 0,05. The clinical significance was assessed by these levels: d = 0,2-0,49 (small effect), d = 0,5-0,79 (medium effect),...

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