Healthy bone is bombarded with many different mechanical strain derived signals during normal daily activities. One of these signals is present as a direct connective tissue strain on the cells. However, there is also the presence of an electrically charged streaming potential during this straining. The electrical potential is created from the movement of charged fluid through the small bone porosities. To date, little focus has been applied to elucidating the possible synergistic effects of these two stimulants. The aim of this project was to evaluate the effects of mechanical strain and indirect electrical stimulation upon the development of bone forming osteoblast cells and any possible synergistic effects of the two stimulants. This aim was achieved by using a novel device, designed and developed with the capability of creating a cell substrate surface strain along with an exogenous electrical stimulant individually or at the same time. Proliferation and differentiation were determined as a measure of cellular development. The indirect electrical stimulation was achieved through the use of a pulsed electromagnetic field (PEMF) while the mechanical strain was produced from dynamic stretching of a deformable cell substrate. Strain and strain rate were modelled from recent studies proposing that relatively high frequency, low strain osteogenic mechanical stimulants are more indicative of what healthy bone would be experiencing during normal activities. The PEMF signal mimicked a clinically available bone growth stimulator signal. Results showed a PEMF stimulus on monolayers of SaOS-2 and MG-63 osteoblast-like cells leads to a depression in proliferation. A concomitant increase in alkaline phosphatase production was also observed for the SaOS-2 cultures, but not for the MG-63 cell line. It was hypothesised that this was due to the MG-63's lack of phenotypic maturity compared to the SaOS-2 cells. Mechanical strain of the cell substrate alone, at a relatively high frequency (5Hz) but small strain, did not significantly effect either cell proliferation or differentiation for the MG-63 cells. However, when the electrical and mechanical stimulants were combined a significant increase in cellular differentiation occurred with MG-63 cultures, revealing a possible synergistic effect of these two stimulants on the development of bone cells.

Bien qu’il soit recommandé de pratiquer tout au long de sa vie une activité physique régulière pour se maintenir en bonne santé, peu d’études portent sur les modifications des patrons locomoteurs lors de la répétition de séances à 2 ou 3 jours d’intervalle. Lorsqu’elles sont intenses ou inhabituelles, les formes naturelles de locomotion pédestre – dites de type cycle étirement-détente (CED) – se caractérisent par des perturbations structuro-fonctionnelles et proprioceptives qui peuvent perdurer plusieurs jours. Ces déficiences sont autant de sources de risques accrus de blessures lors de la répétition d’une pratique sportive. Ce travail doctoral a pour objectif (i) d’examiner les effets immédiats et retardés d’exercices épuisants de type CED sur les paramètres neuromécaniques de la locomotion humaine en conditions de marche, de course et de sauts et (ii) d’étudier l’influence combinée d’une pratique pieds nus vs. pieds chaussés. Nos résultats ne révèlent pas de modification significative des patrons locomoteurs en phase de récupération immédiate (post-exercice) mais démontrent l’intervention de stratégies compensatrices et/ou protectrices en phase de récupération retardée (2ème jour posteffort). Ces stratégies diffèrent entre les conditions de marche et de course. Nos travaux soulignent également l’importance de discriminer les stratégies adoptées dès la première minute de l’exercice des ajustements ultérieurs apparaissant pendant la phase dite d’optimisation du CED. Par contre, les différences observées entre les conditions de course pieds nus vs. pieds chaussés restent étonnamment similaires avec la fatigue. Le port de chaussures se traduit par une réduction des chocs d’impact mais également par une restriction des mouvements naturels du pied et par une éversion accrue dont il conviendrait d’étudier les conséquences lors de la répétition en état de fatigue d’exercices de plus longue durée. / Although lifelong practice of moderate amounts of regular physical activity is recommended to ensure a healthy living state, little is know about the modifications of the locomotion patterns when repeating exercises every 2 to 3 days. Intense or unaccustomed stretch-shortening cycle (SSC) forms of ground locomotion are characterized, however, by structuro-functional and proprioceptive impairments that may last for a few days. These impairments may then be expected to increase the risk of injury. The present work aimed (i) to examine the acute and delayed SSC fatigue effects on the neuro-mechanical gait characteristics in walking, running and jumping conditions and (ii) to study the combined influence of a barefoot vs. shod gait condition. Our results did not reveal any modification of the locomotion patterns in the acute recovery phase (post-exercise), but demonstrated compensatory and/or protective strategies in the delayed phase (2 days post-exercise). The observed strategies differed significantly in walking and running. Our results emphasized also the need to differentiate the strategies occurring within the first minute of exercise from the subsequent adjustments related to the progressive SSC pattern optimization. Surprisingly, the observed differences between the barefoot and shod running conditions remained quite independent of the fatigue state. The shod running condition was thus found to attenuate ground impact transmission, but it resulted also in restricted natural foot motions and increased eversion that should be worth re-examining when repeating exercises of longer duration.

Made available in DSpace on 2014-12-17T15:14:49Z (GMT). No. of bitstreams: 1 RicardoGS.pdf: 538526 bytes, checksum: 84faa5411061c273b56347caa03d1fac (MD5) Previous issue date: 2008-09-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This dissertation analyses the influence of sugar-phosphate structure in the electronic transport in the double stretch DNA molecule, with the sequence of the base pairs modeled by two types of quasi-periodic sequences: Rudin-Shapiro and Fibonacci. For the sequences, the density of state was calculated and it was compared with the density of state of a piece of human DNA Ch22. After, the electronic transmittance was investigated. In both situations, the Hamiltonians are different. On the analysis of density of state, it was employed the Dyson equation. On the transmittance, the time independent Schr?dinger equation was used. In both cases, the tight-binding model was applied. The density of states obtained through Rudin-Shapiro sequence reveal to be similar to the density of state for the Ch22. And for transmittance only until the fifth generation of the Fibonacci sequence was acquired. We have considered long range correlations in both transport mechanism / Esta disserta??o analisa a influ?ncia do esqueleto a??car-fosfato no transporte eletr?nico na mol?cula de DNA de fita dupla, com o sequenciamento dos pares de base modelado por dois tipos de seq??ncias quasi-peri?dicas: Rudin-Shapiro e Fibonacci. Para ambas as seq??ncias, foram calculadas as densidades de estado e comparadas com a densidade de estado de um trecho do DNA humano Ch 22. Em seguida, foi investigada a transmit?ncia eletr?nica. Nos dois casos, as Hamiltonianas s?o distintas. Na an?lise da densidade de estado foi empregada a equa??o de Dyson. Na transmit?ncia foi feito uso da equa??o de Schr?dinger independente do tempo. Em ambos os casos, foi utilizado o modelo tight-binding. Os resultados para a densidade de estado foram mais satisfat?rios para a seq??ncia de Rudin-Shapiro, que forneceu um perfil muito pr?ximo do perfil da densidade de estado para o Ch22. A transmit?ncia foi calculada somente para a seq??ncia de Fibonacci at? a quinta gera??o. Nestes dois mecanismos de transporte, as correla??es s?o de longo alcance

Conselho Nacional de Desenvolvimento Científico e Tecnológico / A espasticidade é observada na maioria dos pacientes após Acidente Vascular Encefálico (AVE), e exercem influência na presença de deficiências e incapacidades, comprometendo a função motora. As estratégias de neuroreabilitação, o biofeedback eletromiográfico (EMG), têm sido utilizado com aceitação na comunidade médica para reajustes nas habilidades sensório-motoras como retreinamento motor, redução da espasticidade e/ou treinamento de relaxamento. A intervenção ainda apresenta evidências delimitadas quanto a sua efetividade na reabilitação, principalmente, quanto a interferência sobre a atividade cortical e na redução dos sinais espásticos que oferece características negativas na execução do movimento. O objetivo dessa pesquisa foi analisar a possível interferência do treino com biofeedback eletromiográfico sobre a conscientização do controle motor no membro espástico e a caracterização da atividade das bandas de baixa frequência em diferentes regiões corticais orientada pela técnica de treinamento. Dezesseis voluntários acometidos por AVE isquêmicos foram selecionados e divididos em dois grupos (n=8). Grupo experimental (GE) submetidos ao treino com biofeedback associado a fisioterapia, e o grupo controle (GC) submetido apenas à fisioterapia convencional. Foi realizada a avaliação do grau de espasticidade pelo limiar de reflexo do estiramento tônico (LRET) e pela Escala Modificada de Ashworth (EMA) antes e três semanas após o término do treinamento com a técnica. Os sujeitos foram submetidos ao biofeedback durante 6 semanas, com 2 sessões semanalmente. O mesmo tempo para o tratamento fisioterápico foi padronizado para o GC. Os resultados mostram variação do percentual médio de melhora do grau de espasticidade, mensuradas pelo LRET, de 38,59% (dp=13,03%) no GE comparado com 18,58% (dp=11,90%) do GC. Essa variação apresentou diferença significativa (p=0,020; t=2,776; p<5%) entre os grupos (controle e experimental), e a diferença significativa do LRET antes e após do treinamento no GE (p=0,003; t=5,338; p<5%) quando comparado ao GC (p=0,015; t=3,657; p<5%). A medida semi-quantitativa da EMA antes e após o término das sessões mostraram variações apenas no GE. Com relação a atividade cortical, houve diferença de atividade das bandas (delta, teta, alfa e beta) quando a 3ª e 12ª sessão foram comparadas para cada sujeito do GE. Essa diferença foi encontrada, principalmente, em regiões frontal, central (vértex), parietal e occipital em ambos hemisférios (ipsilateral e contralateral a lesão) tanto na fase de planejamento cognitivo motor quanto na execução do movimento. Houve predominância da diferença de atividade para a banda delta, alfa e beta em diferentes sujeitos distribuída difusamente ao longo dos canais de registro de viii EEG. A atividade diferenciada das bandas foi devido ao aumento e/ou diminuição da energia espectral entre as sessões, notado apenas em alguns voluntários do GE. Observou ainda diferença de atividade em áreas motoras secundárias. As avaliações, principalmente do LRET mostram que o treino com biofeedback EMG foi efetivo na redução do grau de espasticidade. A diferença de atividade cortical das bandas de frequência entre as sessões sugere que o biofeedback modula a cognição por meio do esforço e atenção imposta pela tarefa na tentativa do movimento no membro acometido. Além de que a diferença de energia espectral entre as sessões é dependente do ajuste e complexidade da tarefa direcionado pelos sinais do biofeedback, auxiliando na aprendizagem motora. / Spasticity is observed in most patients after cerebrovascular accident (CVA), and exerts influence in the presence of disabilities, affecting motor function. For neurorehabilitation strategies, electromyographic biofeedback (EMG) has been used with acceptance in the medical community for adjustments in the sensory-motor skills as a motor retraining, reducing spasticity and/or relaxation training. The intervention still presents limited evidence regarding their effectiveness in rehabilitation, especially as the interference of cortical activity and the reduction of spastic signs that provides negative characteristics in movement execution. The aim of this study was to analyze the workout possible interference with EMG biofeedback on the motor control awareness in spastic member in the characterization of the activity of low-frequency bands in different cortical regions targeted by the training technique. Sixteen volunteers affected by ischemic stroke were selected and divided into two groups (n = 8). Experimental group (EG) underwent biofeedback training associated with physical therapy and control group (CG) only conventional physiotherapy. The assessment of the degree of spasticity by reflex threshold of the tonic stretch (TSRT) and Modified Ashworth Scale (MAS) was performed before and three weeks after the end of treatment with the technique. The subjects underwent biofeedback for 6 weeks, with two sessions weekly. The same time for physiotherapy treatment was standardized to the GC. The results show variation of the average percent improvement in the degree of spasticity measured at TRST, 38,59% (sd=13,03%) in GE compared to 18,58% (sd=11,90%) of GC. This variation showed a significant difference (p=0.020; t=2,776; p<5%) between groups (control and experimental), and the significant difference of TRST before and after training in EG (p = 0.003; t=5,338; p <5%) when compared to the CG (p=0.015; t=0,015; p<5%). The semi-quantitative measure of the MAS before and after the end of the sessions presented variations only in GE. Regarding the cortical activity, there were band activities differences when 3rd and 12th sessions were compared for each subject of GE. This difference was found primarily in the frontal, central (vertex), parietal and occipital lobe in both hemispheres (contralateral and ipsilateral to the lesion) in both the cognitive motor planning phase and in the movement execution. It was observed the predominance of activity difference for the delta band, alpha and beta in different subjects distributed diffusely over the EEG recording channels. The different activity of the bands was due to the increase and/or decrease the spectral energy between sessions, x noticed only in some GE volunteers. It was also pointed out distinct activity in secondary motor areas. Evaluations mainly from TSRT show that training with EMG biofeedback was effective in reducing the degree of spasticity. The difference in cortical activity of the frequency bands between sessions suggested that biofeedback modulates cognition through the effort and attention required by the task of movement attempt in the affected limb. Besides that, the spectral energy difference between the sessions depends on the tuning and task complexity driven by biofeedback signals, helping motor learning. / Tese (Doutorado)

Submitted by Rosangela Silva (rosangela.silva3@unioeste.br) on 2018-06-25T14:39:55Z No. of bitstreams: 2 Douglas Ticiani Final.pdf: 15543424 bytes, checksum: 41d19b956e10c7116d923cf4330efe56 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-06-25T14:39:55Z (GMT). No. of bitstreams: 2 Douglas Ticiani Final.pdf: 15543424 bytes, checksum: 41d19b956e10c7116d923cf4330efe56 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-06-11 / Run of River hydroelectric systems, beyond fragments aquatic environments, drastically reduced as flow discharges in the Reduced Flow Stretch (RDS). The objective of this study was to evaluate the influence of TVR formation and environmental variables on composition and spatial distribution of eggs and larvae, in dams cascade operating with free threshold and under the Run of River system. Fortnightly nocturnal samplings were carried out between October/2016 and January/2017, in four points of influence area of the Rio das Antas Energy Complex, Patos Lagoon ecoregion. The ichthyoplankton was collected with conical-cylindrical networks, in three sections of the river and by a light trap per point. The eggs were quantified, while larvae were identified using the sequence regression development technique, framed in larval periods (larval yolk, pre-flexion, flexion and post-flexion) and juvenile. Were collected 5,681 eggs, 2,124 larvae and 43 juveniles, belonging to 25 taxonomic groups. Small species, sedentary and without parental care (small characids) had the highest total abundance and density. Significant spatial differences were identified in egg and larval densities, as well in the stages of ontogenic development, influenced by flow, temperature, pH and dam-free river stretch. The higher density of upstream larvae and the greater species richness downstream of the complex, indicate disruption in the natural processes of drift and the displacement of many species in the upstream direction. Higher flow rates positively influenced the use of RDS as spawning sites. / Hidrelétricas que desviam o rio, além de fragmentar os ambientes aquáticos, reduzem drasticamente as descargas de fluxo hídrico nos Trechos de Vazão Reduzida (TVRs). O objetivo desse estudo foi avaliar a influência da formação de TVR’s e das variáveis ambientais na composição e a distribuição espacial de ovos e larvas, em um complexo de barragens em sequência, que operam com soleira livre e sistema de desvio do rio e soleira livre. Foram realizadas amostragens quinzenais noturnas entre outubro/2016 e janeiro/2017, em quatro pontos na área de influência do Complexo Energético Rio das Antas, ecorregião Lagoa dos Patos. O ictioplâncton foi coletado com redes cônico-cilindricas, em três secções do rio e por uma armadilha luminosa por ponto. Os ovos foram quantificados, enquanto as larvas foram identificadas através da técnica de sequência regressiva de desenvolvimento, enquadradas em períodos larval (larval vitelino, pré-flexão, flexão e pós-flexão) e juvenil. Foram coletados 5.681 ovos, 2.124 larvas e 43 juvenis, pertencentes a 25 grupos taxonômicos. Espécies de pequeno porte, sedentárias e sem cuidado parental (pequenos caracídeos) foram as maiores contribuintes para a abundância e densidade totais. Foram identificadas significativas diferenças espaciais nas densidades de ovos e larvas, bem como nos estágios de desenvolvimento ontogênico, influenciadas pela vazão, temperatura, transparência, pH e trecho de rio livre. A maior densidade de larvas à montante e a maior riqueza de espécies a jusante do complexo, indicam interrupção nos processos naturais de deriva e dispersão de muitas espécies no sentido montante. Maiores vazões influenciaram positivamente a utilização dos TVRs como sítios de desova.

[pt] Em apresentações hipermídia, umas das principais tarefas coordenadas pelo orquestrador da apresentação é a sincronização entre os diversos objetos componentes, que pode ser obtida através do ajuste elástico do tempo de exibição dos objetos. Esta técnica pode ser aplicada em tempo de compilação, de forma a manter os relacionamentos de sincronização especificados pelo autor, ou em tempo de apresentação, para prevenir qualquer descasamento temporal causado pelos ambientes de transmissão e de execução. Este trabalho descreve um conjunto de mecanismos para executar o ajuste elástico em fluxos MPEG-2 de Vídeo e de Sistemas, propondo algoritmos para a realização da compressão e expansão do tempo de exibição, do controle da ocupação do buffer do decodificador, da sincronização intermídia e da reconstrução do relógio de referência. Visando seu emprego em tempo de execução, todo o processo de ajuste é realizado diretamente no fluxo MPEG, sem qualquer transcodificação. / [en] In hypermedia presentations, one of the main tasks provided by the orchestrator is the synchronization of all presentation objects, which may be achieved by elastic time adjustment of period of exhibition of the objects, or simply timescale adaptation. This technique can be applied at compilation time, in order to keep track of synchronism relationships specified by authors, or at presentation time, to prevent any temporal mismatch caused by transmission or execution environments. This work presents a set of mechanisms to carry out timescale adaptation in MPEG-2 Systems and Video streams, proposing algorithms to perform compression and expansion of exhibition period, also called playback dilation, rate control, inter-media synchronization and clock reconstruction. In order to be performed at execution time, timescale operations are realized directly in compressed MPEG-2 streams, requiring no transcodification.

INTRODUCTION. Congenital diaphragmatic hernia (CDH) combines a congenital malformation of the diaphragm with lung hypoplasia, leading to severe respiratory distress and intractable pulmonary hypertension of the newborn. Despite advances in prenatal diagnosis and neonatal intensive care, CDH is associated with high mortality and devastating morbidities. In the absence of curative treatment, numerous prenatal therapies have been used experimentally with varying success. So far, only fetal tracheal occlusion has been tested in clinical trials, but the consequences for the human lung are poorly known. AIMS. To further characterize the rabbit model of CDH, which was subsequently used to assess the effects of prenatal therapies on airway and pulmonary vascular development, including tracheal occlusion, and two novel approaches, perfluorooctylbromide and an activator of soluble guanylate cyclase (BAY 41–2272), which were given through tracheal instillation.METHODS. After a diaphragmatic incision during the pseudoglandular stage, fetal rabbits were randomized against placebo/sham operation during the saccular stage for tracheal occlusion, perfluorocarbon or BAY 41–2272. At term operated fetuses and controls were subject to evaluation of lung mechanics and/or hemodynamics as well as postmortem lung analyses. Human fetal and neonatal lung tissue, including controls and CDH with tracheal occlusion or expectant management, was analyzed histologically and biochemically.RESULTS. The rabbit model of CDH was characterized by reduced lung volumes and impaired compliance, disorders of elastin deposition within alveolar walls, and downregulation of elastogenesis-related genes. Moreover, this model reproduced features of pulmonary hypertension, including high right ventricular pressure and level of N-terminal-pro-B type natriuretic peptide, remodeling of pulmonary arterioles, decreased alveolar capillary density, and downregulation of vasodilation-related genes. In the rabbit model, lung distension caused by tracheal occlusion improved alveolar formation and elastogenesis, yet without correction of lung mechanical parameters. Tracheal occlusion increased also the expression of other extracellular matrix components, which reflected myofibroblast activity, and reduced the transcription of surfactant-associated proteins. Human neonatal lungs exposed to fetal tracheal occlusion displayed alveolar deposits of collagen and myofibroblasts. In human CDH as well as in the rabbit model of CDH, tracheal occlusion enhanced the pulmonary expression of transforming growth factor-β (TGFβ) and Rho kinase−associated proteins to the detriment of activation of SMAD2/3, which is normally detected in human lungs with advancing gestation. As an alternative to tracheal occlusion, pulmonary distension by perfluorocarbon in the fetal rabbit model of CDH improved lung mechanics and alveolar elastogenesis without transcriptional changes in extracellular matrix, surfactant protein genes or TGFβ. Finally, intratracheal instillation of BAY 41–2272 in the rabbit fetuses with CDH improved hemodynamics, reduced medial hypertrophy of pulmonary arterioles, and increased capillary bed formation by stimulating endothelial cell proliferation.CONCLUSIONS. In the fetal rabbit model of CDH, poor lung function after tracheal occlusion is compatible with activation of TGFβ and imbalance in extracellular matrix and epithelial homeostasis. In human CDH newborns treated by fetal tracheal occlusion, changes in the pulmonary interstitium and impaired TGFβ signaling raise the question of disturbances of postnatal lung development induced by tracheal occlusion. As potential alternatives to tracheal occlusion, prenatal perfluorocarbon improves lung hypoplasia, whereas prenatal BAY 41–2272 attenuates pulmonary hypertension. / Doctorat en Sciences médicales (Médecine) / info:eu-repo/semantics/nonPublished

The thesis discusses the roads in lanes 2 + 1 arrangement in the country and abroad. It focuses primarily analogy of this type of arrangement in our situation, ie on stretches of roads I. classes with an increased number of lanes for slow vehicles to climb. Part of this work is to verify some of the traffic, including traffic flow characteristics compared to conventional two-lane roads, especially in terms of: sectional speed; overtaking; Accident and dependence longitudinal gradient. The work aims to evaluate the foreign experience and achievements of domestic communications options for application configuration 2 + 1 in the Czech Republic.

Bien qu'étudiée depuis plus de 100 ans, la détermination expérimentale de la vitesse de combustion reste compliquée. Dans ce travail de thèse, la configuration de flamme sphérique en expansion a été choisie. Cependant, il apparait plusieurs formulation pour cette vitesse de combustion. Ces dernières sont liées au référentiel de mesure qui est lié 1) au laboratoire, 2) au front de flamme et 3) au taux de réaction. Ces 3 formulations, bien que différentes par définition, doivent cependant converger vers une seule et unique valeur correspondant à la vitesse de combustion laminaire à étirement nul. Une étude comparant ces formulations pour des mélanges gazeux au nombre de Lewis bien défini a été menée. Il est montré que la formulation associée au front de flamme permet d'extraire une vitesse de combustion s'abstenant de toute hypothèse. Cette technique a été ensuite appliquée pour déterminer la vitesse de combustion de mélanges issoctane/éthanol et leur dépendance en pression (10 bars). / Laminar burning velocity is very useful for both combustion modeling and kinetic scheme validationand improvement. Accurate experimental data are needed. To achieve this, the spherical flame method was chosen. However various expression for burning velocity from the spherically expanding flame can be found. A theorical review details all the expressions and models for the burning veolcity and shows how they can be obtained experimentally. These models were comparated considering basic fuels - various Lewis numbers. As a result, it is shown that the pure kinematic measurement method is the only one thet does not introduce any assumptions. This kinematic measurement had needed the development and validation of an original post-processing tool. Following the theorical review, a parametric experimental study is presented. The new technique is extended to extract burning velocity and Markstein length relative to the fresh gas for pure ethanol, isooctane and blended fuels at high pressure.

No description available.