Les ARN messagers (ARNm) fonctionnels sont produits au cours d'un mécanisme complexe qui allie la transcription, qui permet la synthèse d'un pré-ARNm, la maturation de ce transcrit et son export. De plus, ces différentes machineries vont devoir faire face à la structure compacte de la chromatine, nécessitant une activité de décondensation/recondensation de la chromatine qui est notamment régulée par les mécanismes épigénétiques. Un très grand nombre de facteurs sont donc requis pour la production des ARNm fonctionnels . Parmi ces facteurs, les protéines Spt6 et Iws1 sont impliquées dans le mécanisme général de la transcription, dans la modulation de la structure de la chromatine et la maturation et l'export des ARNm. Ces travaux de thèse ont permis de caractériser biochimiquement, structuralement et fonctionnellement ces deux protéines, leur complexe et leur interaction avec d'autres effecteurs de la transcription. Ces travaux ont notamment permis de comprendre en termes moléculaires et fonctionnels (i) comment Spt6 est recrutée par l'ARN polyméraseII au cours de la transcription et (ii) comment le complexe Spt6/Iws 1 est formé. Ils ont également permis d'identifier de nouveaux interactants potentiels de Spt6, et notamment le facteur d'élongation de la transcription TFIIS. Ces travaux ont ainsi permis de révéler le rôle essentiel et extrêmement complexe joué par Spt6 et Iws1 lors de la production d'un ARNm, mais également de permettre l'étude future de leur interaction avec d'autres facteurs transcriptionnels. / Production of functional messenger RNA (mRNA) requires a complex mechanism that couples transcription with maturation and export of the mRNA. In addition to this mechanism, chromatin needs to be unwound to allow the transcription machinery access the DNA, this unwinding being also highly regulated. Thus, production of a functional mRNA requires a huge number of factors implicated in these different processes. Among these proteins Spt6 and Iws1 are participating in the mechanism of transcription, chromatin unwinding, and maturation and export of the mRNA. The work carried out during this thesis has enabled the biochemical, structural and functional characterization of these proteins, their complex and their interaction with other effectors of transcription. This work has specifically enabled the molecular and functional characterization (i) of the recruitment of Spt6 by RNA polymerase II and (ii) of the formation of the Spt6/Iws1 complex. Moreover, this work has identified putative new partners of Spt6, not ably the elongation factor TFIIS. Thus, our work has highlighted the essential and complex role of Spt6 and Iws1 during the production of functional mRNA, and has also enabled future studies of the complexes formed by these two proteins with other transcriptional factors.

L'élongation embryonnaire de C. elegans a lieu en deux étapes. La première phase est permise par les contractions d’actomyosine et régulée par les kinases let-502 et pak-1. La seconde dépend des contractions musculaires (après le stade 1,7-fold). La tension fournie par ces contractions permet le recrutement de GIT-1 aux hémidesmosomes, facilitant la poursuite de l’élongation via l’activation de PAK-1 (Nature, 2011). Étonnamment, en l'absence de git-1 ou pak-1, l'élongation se poursuit, nous conduisant à émettre l'hypothèse de voies de régulation parallèles. Un crible ARNi a été réalisé pour rechercher les candidats impliqués. La majorité des candidats interagissant fortement avec git-1 appartenait au complexe dynéine-dynactine. En utilisant des allèles sensibles à la température et des protéines affectant les microtubules, nous avons décrit un rôle de la dynactine indépendant des microtubules dans l'épiderme ainsi que son interaction avec la spectraplakine vab-10 et la spectrine spc-1. / C. elegans embryonic elongation is driven by 2 forces: Actomyosin contractility and Muscle contraction (after 1.7-fold). Actomyosin contraction is regulated by the Rho kinase and the serine/threonine p21 activated kinase pak-1. Tension provided by muscle contraction recruits GIT-1 to hemidesmosomes (HD), which in turn facilitates further elongation by activating proteins such as PAK-1 (Nature 2011). Surprisingly in absence of git-1/pak-1, elongation still continues, which led us to hypothesize parallel pathways. An RNAi screen was performed to get the candidates in the parallel pathway/s. Candidates interacting strongly with git-1 belonged to the Dynein Dynactin complex. By use of temperature sensitive alleles and microtubule severing proteins, we found a microtubule independent role of Dynactin in epidermis and that dynactin functionally interacts with spectraplakin vab-10 and spectrin spc-1, which allows us to portray the role of Dynein Dynactin complex during embryonic elongation.

Introdução: Estiramento muscular e outras desordens músculoesqueléticas são as principais causas que desabilitam atletas e praticantes de atividades físicas. Seu tratamento inclui AINES que desencadeiam vários efeitos adversos. O objetivo do estudo foi investigar os efeitos da Terapia Laser de Baixa Intensidade (810nm) sobre absorção do diclofenaco aplicado topicamente, além de investigar uma sinergia entre ambos. Métodos: Foram quantificadas concentrações plasmáticas de diclofenaco em diferentes tempos, com e sem irradiação do laser, em ratos Wistar fêmeas. Ratos foram submetidos à indução do estiramento muscular. Os grupos tratados receberam irradiação do Laser, antes da droga, 1 hora após a indução da lesão, para analisar índice funcional, estudo eletrofisiológico, expressão gênica RT-PCR de COX-1 e COX-2, PGE2 por espectrofotometria e histologia. Resultados/Discussão: A utilização do Laser de Baixa Potência aumentou a biodisponibilidade da droga e reduziu a inflamação e a lesão após estiramento experimental, conduzindo a uma melhora da atividade de caminhar. / Introduction: Stretch muscle and other musculoskeletal disorders are the main causes that disable the athlete and physically active practitioner. It´s treatment includes NSAIDs that trigger adverse effects. The aim of the study was to investigate the effect of Low Level Laser Therapy (810nm) on the absorption of topically applied diclofenac, and investigate a synergy between them. Methods: quantify the plasma concentrations of diclofenac in different times, with and without laser irradiation in Wistar female rats. Female Wistar rats were subjected to induction of muscle stretch. The groups received laser irradiation, prior to application of the drug, one hour after induction of the injury, to analyze the sciatic index functional, electrophysiological studies, gene expression by RT-PCR of COX-1 and COX-2, PGE2 by spectrophotometry and histology. Results/Discussion: The use of Low Level Laser Therapy increased the bioavailability of the drug and reduced inflammation and muscle damage after stretch experiment, leading to a significant improvement in walking activity.

O objetivo deste estudo foi avaliar o crescimento e desenvolvimento de brotações de progênies de Eucalyptus grandis in vitro. Brotações oriundas de explantes de hipocótilos distais de 10 progênies foram utilizadas no meio de cultura JADS (CORREIA et al., 1995). Utilizou-se o delineamento experimental inteiramente casualizado, com 10 tratamentos (10 progênies). No meio de cultura suplementado com 0,5 mg L-1 de BAP e 0,1 mg L-1 de AIA, efetuaram-se 3 subcultivos e aos 63 dias foram avaliadas as massas fresca e seca. O meio de cultura com 0,1 mgL-1 de BAP foi utilizado no alongamento das brotações e em brotações individualizadas. No alongamento de brotações, procederam-se 3 subcultivos, e aos 63 dias foram avaliadas as massas fresca e seca e número de brotações. No alongamento de brotações individualizadas, aos 21 dias foram avaliadas a altura e a ocorrência de raízes. Existiram respostas diferenciadas das progênies; algumas progênies mostraram maior produção de massa fresca e seca e outras se destacaram no alongamento e enraizamento in vitro. / The aim of this work was to evaluate the growth and development of eucalyptus grandis progeny shoots in vitro. Shoots from distal hypocotyl explants of 10 progenies were cultivated in the JADS (CORREIA et al., 1995) tissue culture medium. The culture medium was suplemented with 0,5 mg L-1 de BAP e 0,1 mg L-1 de IAA. Three subcultures where made and at 63rd day of culture, the fresh and oven dry weight and number of shoots were evaluated. At the elongation phase, using the culture medium suplemented with 0,1 mg L-1 de BAP, three subcultures were made and at the 63rd day of culture, fresh and oven dry weight, shoot height and rooting percentage were evaluated. There were differentiated progeny responses. Some showed higher fresh and oven dry weight production and others showed higher elongation rates and rooting percentage.

A exemplo do que ocorre em animais, peptídeos hormonais em plantas desempenham papéis importantes no crescimento, desenvolvimento e defesa. RALF é um peptídeo hormonal ubíquo em plantas que foi primeiramente isolado de folhas de tabaco. Embora não se saiba exatamente sua função, as informações até agora existentes apontam para um envolvimento com aspectos básicos da biologia celular, provavelmente alongamento celular. Peptídeos RALF em Arabidopsis são encontrados em uma família multigênica de 37 membros. Plantas transgênicas superexpressando o AtRALF1 sob o controle do forte promotor constitutivo 35S, mostram um fenótipo semi-anão e inibição do crescimento das raízes. Um fenótipo semelhante também foi observado quando o AtRALF23 foi superexpresso. O AtRALF23, ao contrário do AtRALF1, tem sua expressão inibida por brassinosteróides. Esses fatos sugerem que diferentes peptídeos hormonais RALF, apesar de convergirem para a mesma função, apresentam uma relação individualizada com outros hormônios. O objetivo desse trabalho foi contribuir para a determinação da função dos peptídeos RALF em plantas e para o esclarecimento da inter-relação existente entre eles e os demais hormônios vegetais. Para tal, selecionou-se as isoformas AtRALF1 e AtRALF34 com base em semelhança/dessemelhança estrutural e padrão de expressão. Plantas silenciadas e com altos níveis de expressão para ambos os genes foram obtidas e avaliadas. A construção gênica AtRALF1-GFP foi inserida em Arabidopsis sob o controle do promotor 35S e foi observada fluorescência no retículo endoplasmático, complexo de Golgi e apoplasto. Genes anteriormente reportados como induzidos em plantas 35S:AtRALF1 foram validados e utilizados em experimentos com o AtRALF1 e o brassinolide. O conjunto dos resultados sugere um efeito antagônico do peptídeo AtRALF1 com relação ao efeito do brassinolide no alongamento de hipocótilos e raízes. Plantas com altos níveis de AtRALF1 são resistentes a aplicação exógena de brassinolide, não exibindo as respostas características do hormônio esteróide. O antagonismo entre os dois hormônios também foi sugerido pela análise da expressão de genes que são induzidos por AtRALF1 e brassinolide. / Like in animals, plant peptide hormones play important roles in growth, development and defense. RALF is a peptide hormone ubiquitous in plants that was first isolated from tobacco leaves. Although its function has not been established, the information gathered so far suggest its involvement with basic aspects of cellular biology, probably cellular elongation. RALF peptides in Arabidopsis are found in a multigene family of 37 members. Transgenic plants overexpressing AtRALF1 under the control of the strong constitutive promoter 35S, show a semi-dwarf phenotype and root growth inhibition. A similar phenotype was also observed when AtRALF23 was overexpressed. AtRALF23, as opposed to AtRALF1, is inhibited by brassinosteroids. These facts suggest that different RALF peptide hormones, despite the convergence to the same function, show a unique relationship with other hormones. The goal of this work was to contribute to the determination of the function of RALF peptides in plants and to clarify the inter-relationship between RALF and the other plant hormones. With that in mind, the isoforms AtRALF1 and AtRALF34 were selected based on primary structure similarity/dissimilarity and pattern of gene expression. Plants with high levels of expression or silenced for both genes were obtained and evaluated. The gene construct AtRALF1-GFP was introduced in Arabidopsis under the control of the 35S promoter and fluorescence was observed in the endoplasmic reticulum, Golgi apparatus and apoplast. Genes previously reported as induced in 35S:AtRALF1 plants were validated and used in AtRALF1 peptide and brassinolide experiments. Taken together our results suggest an antagonistic effect of the peptide AtRALF1 regarding the elongation effect of brassinolide in hypocotyls and roots. Plants with high levels of AtRALF1 are resistant to exogenously applied brassinolide, and do not show typical responses to the steroid hormone. The antagonism between the two hormones was also suggested by the gene expression analysis of the AtRALF1 and brassinolide inducible genes.

Ce travail de thèse vise à mieux décrire les mécanismes de lésions de la tête humaine en situation de choc en optimisant le modèle par éléments finis de la tête humaine de Strasbourg (SUFEHM) en termes de modélisation mécanique du crâne et du cerveau grâce à de nouvelles données expérimentales et de techniques récentes d’imagerie médicales. Une première étape a consisté à améliorer la loi de comportement de la boîte crânienne, valider son comportement en regards d’éléments expérimentaux sur cadavres et proposer un MEF capable de reproduire fidèlement la fracture crânienne. La deuxième partie consiste en la prise en compte pour la première fois de l’anisotropie dans les simulations par EF d’accidents réels en utilisant l’Imagerie du Tenseur de Diffusion. Après implémentation, une phase de validation a été entreprise afin de démontrer l’apport de l’anisotropie de la matière cérébrale dans un MEF. Enfin 125 accidents réels ont été reproduits avec le SUFEHM ainsi amélioré. Une étude statistique sur les paramètres mécaniques calculés a permis de proposer des limites de tolérances en termes de fracture crânienne et de lésions neurologiques en s’intéressant tout particulièrement à l’élongation axonale maximale admissible, nouvelle métrique proposée. / The principal objective of this study is to enhance the existing finite element head model. A composite material model for skull, taking into account damage is implemented in the Strasbourg University Finite Element Head Model in order to enhance the existing skull mechanical constitutive law. The skull behavior is validated in terms of fracture patterns and contact forces by reconstructing 15 experimental cases in collaboration with Medical College of Wisconsin. The new skull model is capable of reproducing skull fracture precisely. The composite skull model is validated not only for maximum forces, but also for lateral impact against actual force time curves from PMHS for the first time. This study also proposes the implementation of fractional anisotropy and axonal fiber orientation from Diffusion Tensor Imaging of 12 healthy patients into an existing human FE head model to develop a more realistic brain model with advanced constitutive laws. Further, the brain behavior was validated in terms of brain strain against experimental data. A reasonable agreement was observed between the simulation and experimental data. Results showed the feasibility of integrating axonal direction information into FE analysis and established the context of computation of axonal elongation in case of head trauma. A total 125 reconstructions were done by using the new advanced FEHM and the axonal strain was found to be the pertinent parameter to predict DAI.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / The objective of this study was to evaluate the use of a thermal sum rest period on natural grassland as a grazing management, these grazing intervals has been used since 2009. During April 2013 to April 2014, we evaluated the effect of this grazing management on vegetation and its consequences in the performance, grazing behavior and dry matter intake of beef heifers on Pampa biome (southern Brazil). A complete randomized block design experiment with two treatments and three replications was conducted with Angus heifers. The treatments were two thermal sums: 375 and 750 degrees-days (DD) determined by the intervals between rotational grazing periods, the 375 DD treatment favors prostrate species (Axonopus affinis and Paspalum notatum) and the 750 DD treatment favors tussock species (Aristida laevis and Saccharum angustifolius). The 23 ha experimental area was divided into six experimental units, which housed two treatments and three replications. The experiment was conducted with beef cattle heifers testers with average age of 7 months old and initial weight of 150.5 ± 5 kg. Every heifers received whole rice bran supplement at a rate of 1.0% of body weight per day during cool season (April to September) and had free access to mineral supplement. Treatments had no differences on vegetation, average daily weight, dry matter intake, grazing behavior variables and beef production. Thermal sum rest intervals could be a valuable grazing management tool to improved animal production per area and forage quality, besides high animal stocking rate. / O objetivo deste trabalho foi avaliar a utilização de duas somas térmica, expressa em graus-dia, como intervalo de descanso entre pastejos em pastagem natural. Durante Abril de 2013 a Abril de 2014, foi avaliado o efeito do manejo do pasto, na vegetação e suas consequências no desempenho, comportamento ingestivo e no consumo de matéria seca de bezerras de corte manejadas em pastoreio rotativo. O delineamento experimental foi o de blocos completamente casualizados, com dois tratamentos e três repetições de área, as repetições foram subdivididas em sete e oitos piquetes, para cada um dos tratamentos. O experimento foi realizado em área pertencente à Universidade de Santa Maria, localizada região fisiográfica da Depressão Central do Rio Grande do Sul, Brasil. Os tratamentos foram duas somas térmicas: 375 e 750 graus-dias (GD), que determinaram os intervalos entre os pastoreios, o tratamento de 375 GD, foi definido pela duração da expansão foliar de espécies de crescimento prostrado (Axonopus affinis e Paspalum notatum) e o tratamento de 750 GD, pela duração da expansão foliar de espécies cespitosas (Aristida laevis e Saccharum angustifolius). A área experimental possuía 23 ha e foi dividida em seis unidades experimentais, que abrigaram os dois tratamentos e as três repetições. Trinta bezerras de corte da raça Red Angus foram utilizadas como animais testers e número variável de reguladoras da mesma categoria e raça. As bezerras possuíam idade média inicial de 7 meses e peso médio inicial de 150 ± 5 kg. Durante a estação fria as bezerras receberam farelo de arroz integral corrigido com 4% de calcário calcítico, como suplemento a uma taxa de 1,0% do peso vivo diariamente às 14 horas. Em ambos os tratamentos a massa de forragem, o desempenho, o comportamento ingestivo e o consumo de matéria seca não diferiram (P<0.05). A soma térmica em graus-dia baseada na característica morfogênica, taxa de elongação foliar como intervalo de descanso entre pastejos pode ser uma ferramenta de manejo para melhorar a produção animal por área, a qualidade da forragem, além de possibilitar elevada taxa de lotação.

Abstract The purposes of the present research were to compare the outcome after Achilles tendon rupture repair in two postoperative regimens, to compare Achilles tendon elongation in two postoperative treatment methods, to compare the effects of two postoperative methods on motor performance aspects such as simple reaction time, choice reaction time, speed of movement, foot tapping speed and coordination, to test the mechanical properties of the recently developed poly-L/D-lactide (PLDLA) sutures and Maxon® sutures when implanted in the Achilles tendons of rabbits, and to study the histological tissue reactions and biodegradation of these sutures under the same conditions. Isokinetic calf muscle strength scores at the last control check-up were excellent in 56% of the patients in the early motion group, good in 32%, fair in 8%, and poor in 4%, whereas the scores in the cast group were excellent in 29% of cases, good in 50% and fair in 21%. The ankle performance scores were excellent or good in 88% of the patients in the early motion group, fair in 4% and poor in 8%, whereas the scores in the cast group were excellent or good in 92% of cases and fair in 8%. No significant differences were seen between the two groups at 3 months and at the last control checkups with regard to pain, stiffness, subjective calf muscle weakness, footwear restrictions, range of ankle motion, isokinetic calf muscle strength or overall outcome. The complications included 1 re-rupture in the early motion group and 1 deep infection and 2 re-ruptures in the cast group. AT elongation occurred in both groups, but was somewhat less marked in the early motion group. The AT elongation curves rose at first and then fell slowly in both groups. The patients who had less AT elongation achieved a better clinical outcome. AT elongation did not correlate significantly with age, body mass index or isokinetic peak torques. The recovery of motor performance functions such as simple reaction time, choice reaction time, speed of movement, foot tapping speed and coordination did not depend on the two postoperative regimens. The motor functions of the operated leg had obviously recovered to the level of the non-operated leg 12 weeks after the operation. Sutures made of PLDLA were used successfully for Achilles tendon repair in rabbits. There was no significant difference between the in vitro and in vivo tensile strength retention of the sutures. By comparison with Maxon®, PLDLA was found to have a lower initial tensile strength but more prolonged strength retention. The breaking strength values of the Achilles tendons repaired with sutures of these types were not significantly different at 6 weeks. Intratendinous PLDLA sutures formed a thinner fibrous capsule during the 12-week follow-up period than did Maxon® sutures of the same diameter. The suture materials had not been totally absorbed by 12 weeks.

No description available.

Content: With the development of China sports, researches related to sports leather should be paid attention because they usually required higher strength than commonly used leather. In this paper, we focus on the production of gymnastics leather. In gymnastics, the athlete's hand will have high intensity contact with the balance bar, so the gymnastics leather is required to have high intensity performance. At the same time, in order to comply with the ornamental function, gymnastics leather is required to be light color. In this research, glutaraldehyde was used as the main tanning agent, while acrylic polymer and synthetic were used for retanning, in order to obtain high strength, environmentally friendly white gym leather. The shrinkage temperature and mechanical properties of tanned leather were determined and analyzed to determine the suitable tanning agent. Besides, other properties including softness, gas permeability, water permeability, flexing resistance and yellowing-resistance were also measured for selecting proper production process. Therefore, gymnastics leather with ideal performance can be prepared by this method, and the leather conforms to the practical application standard. In addition, the research has guiding significance and application prospect for high strength chrome-free tanned leather. Take-Away: Aldehyde tanning agents and retanning agents, which can be used for gymnastics leather making, were evaluated and selected to achieve ideal effect of finish leather. This research is meaningful to produce not only gymnastics leather but also other sporty leather which require high strength.