Le but de cette thèse est de construire une image couleur de haute qualité, contenant un faible niveau de bruit et d'aliasing, à partir d'une grande séquence (e.g. des centaines) d'images RAW prises avec un appareil photo grand public. C’est un problème complexe nécessitant d'effectuer à la volée du dématriçage, du débruitage et de la super-résolution. Les algorithmes existants produisent des images de haute qualité, mais le nombre d'images d'entrée est limité par des coûts de calcul et de mémoire importants. Dans cette thèse, nous proposons un algorithme de fusion d'images qui les traite séquentiellement de sorte que le coût mémoire ne dépend que de la taille de l'image de sortie. Après un pré-traitement, les images mosaïquées sont recalées en utilisant une méthode en deux étapes que nous introduisons. Ensuite, une image couleur est calculée par accumulation des données irrégulièrement échantillonnées en utilisant une régression à noyau classique. Enfin, le flou introduit est supprimé en appliquant l'inverse du filtre équivalent asymptotique correspondant (que nous introduisons). Nous évaluons la performance et la précision de chaque étape de notre algorithme sur des données synthétiques et réelles. Nous montrons que pour une grande séquence d'images, notre méthode augmente avec succès la résolution et le bruit résiduel diminue comme prévu. Nos résultats sont similaires à des méthodes plus lentes et plus gourmandes en mémoire. Comme la génération de données nécessite une méthode d'interpolation, nous étudions également les méthodes d'interpolation par polynôme trigonométrique et B-spline. Nous déduisons de cette étude de nouvelles méthodes d'interpolation affinées / The aim of this thesis is to build a high-quality color image, containing a low level of noise and aliasing, from a large sequence (e.g. hundreds or thousands) of RAW images taken with a consumer camera. This is a challenging issue requiring to perform on the fly demosaicking, denoising and super-resolution. Existing algorithms produce high-quality images but the number of input images is limited by severe computational and memory costs. In this thesis we propose an image fusion algorithm that processes the images sequentially so that the memory cost only depends on the size of the output image. After a preprocessing step, the mosaicked (or CFA) images are aligned in a common system of coordinates using a two-step registration method that we introduce. Then, a color image is computed by accumulation of the irregularly sampled data using classical kernel regression. Finally, the blur introduced is removed by applying the inverse of the corresponding asymptotic equivalent filter (that we introduce).We evaluate the performance and the accuracy of each step of our algorithm on synthetic and real data. We find that for a large sequence of RAW images, our method successfully performs super-resolution and the residual noise decreases as expected. We obtained results similar to those obtained by slower and memory greedy methods. As generating synthetic data requires an interpolation method, we also study in detail the trigonometric polynomial and B-spline interpolation methods. We derive from this study new fine-tuned interpolation methods

[pt] As aplicações da reconstrução em três dimensões de uma cena real são as mais diversas. O surgimento de sensores de profundidade de baixo custo, tal qual o Kinect, sugere o desenvolvimento de sistemas de reconstrução mais baratos que aqueles já existentes. Contudo, os dados disponibilizados por este dispositivo ainda carecem em muito quando comparados àqueles providos por sistemas mais sofisticados. No mundo acadêmico e comercial, algumas iniciativas, como aquelas de Tong et al. [1] e de Cui et al. [2], se propõem a solucionar tal problema. A partir do estudo das mesmas, este trabalho propôs a modificação do algoritmo de super-resolução descrito por Mitzel et al. [3] no intuito de considerar em seus cálculos as imagens coloridas também fornecidas pelo dispositivo, conforme abordagem de Cui et al. [2]. Tal alteração melhorou os mapas de profundidade super-resolvidos fornecidos, mitigando interferências geradas por movimentações repentinas na cena captada. Os testes realizados comprovam a melhoria dos mapas gerados, bem como analisam o impacto da implementação em CPU e GPU dos algoritmos nesta etapa da super-resolução. O trabalho se restringe a esta etapa. As etapas seguintes da reconstrução 3D não foram implementadas. / [en] There are a lot of three dimensions reconstruction applications of real scenes. The rise of low cost sensors, like the Kinect, suggests the development of systems cheaper than the existing ones. Nevertheless, data provided by this device are worse than that provided by more sophisticated sensors. In the academic and commercial world, some initiatives, described in Tong et al. [1] and in Cui et al. [2], try to solve that problem. Studying that attempts, this work suggests the modification of super-resolution algorithm described for Mitzel et al. [3] in order to consider in its calculations coloured images provided by Kinect, like the approach of Cui et al. [2]. This change improved the super resolved depth maps provided, mitigating interference caused by sudden changes of captured scenes. The tests proved the improvement of generated maps and analysed the impact of CPU and GPU algorithms implementation in the superresolution step. This work is restricted to this step. The next stages of 3D reconstruction have not been implemented.

Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-11-07T20:16:04Z No. of bitstreams: 1 FELIPE SÉRVULO MACIEL COSTA – DISSERTAÇÃO (PPGFísica) 2017.pdf: 4976980 bytes, checksum: eb50b091cd9c69ef0ba3d67fba7d69bb (MD5) / Made available in DSpace on 2018-11-07T20:16:04Z (GMT). No. of bitstreams: 1 FELIPE SÉRVULO MACIEL COSTA – DISSERTAÇÃO (PPGFísica) 2017.pdf: 4976980 bytes, checksum: eb50b091cd9c69ef0ba3d67fba7d69bb (MD5) Previous issue date: 2017-11 / Capes / Há cerca de vinte anos, dois grupos de pesquisadores estudaram o brilho aparente das super novas do tipo Ia(SNe Ia) e, de forma independente, descobriram que a expansão atual do universo é acelerada. Esta descoberta lançou a astronomia para a era da energia escura, componente energética que, dentro da teoria da relatividade geral,é a responsável pela aceleração cósmica. Porém, a presença de uma opacidade cósmica nos dados de super novas pode imitar o comportamento de uma componente escura. Hoje em dia, embora a aceleração cósmica seja sustentada por outras observações astronômicas, uma possível presença de opacidade nos dados das SNe Ia pode levar a erros nas estimativas de parâmetros cosmológicos. Assim, vários trabalhos na literatura tem investigado a hipótese da transparência do Universo utilizando medidas de distâncias de luminosidade de velas-padrão, como supernovas do tipo Ia (SNeIa) e gamma raybursts (GRBs),e de distâncias obtidas pela taxa de expansão de Hubble H(z), sendo estas últimas independentes da hipótese de transparência cósmica. Nesta dissertação, nós fazemos uma revisão bibliográ fica sobre estes trabalhos, nos quais foram usados dados de SNeIa, GRBse H(z). Novos limites sobre a opacidade foram colocados com os mais recentes dados de GRBse H(z) no contexto do modelo padrão da cosmologia. Os resultados obtidos mostraram que a hipótese da transparência cósmica está em acordo com os dados, porém, os resultados vindos das observações de GRBs, que alcançam z > 9, onde z é o redshift, não excluem a presença de alguma fonte de opacidade com alto grau de con fiança estatística. / About twenty years ago, two groups of researchers studying the apparent brightness of type Ia super nova e (SNe Ia), independently discovered that the current expansion of the universe is accelerated. This discovery launched astronomy in to the dark energy era, an energy component that, with in the theory of general relativity, is responsible for the cosmic acceleration. However, the presence of a cosmic opacity in SNe Ia data may mimicthe behavior of a dark component. Now a days, although the cosmic acceleration is supported by other astronomical observations, a possible presence of opacity in the SNe Ia data can lead to errors in the cosmological parameter estimates. Thus, several works in the literature have investigated the universe's transparency hypothesis using measurement so fluminosity distances of standard candles, suchas SNe Ia and gamma ray bursts (GRBs), and distances obtained of the cosmic expansion rate H(z). These last ones being independent of the cosmic transparency hypothesis. In this dissertation, we make a bibliographical review on these works and new limits on opacity were placed with the latest data of GRB sand H(z) in the context of the standard model. We have found that the cosmic transparency hypothesis is in agreement with the data, but the results from the observations of GRBs, which reach z > 9, where z is the it red shift, do not exclude the presence of some source of opacity with a high degree of statistical con dence.

Cette thèse s'intéresse à la préparation, par la technique de la lyophilisation, des aérogelsà base de celluloses et de charges minérales destinés à une utilisation potentielle dans le domainede l'isolation thermique. Le premier objectif de la thèse a été la caractérisation de différentescelluloses (cellulose (PBPD), nanocristaux (NCC) et nanofibrilles oxydées (NFCs)), les chargesminérales (principalement la zéolithe) et les différents aérogels résultants de différentescombinaisons des matériaux de départ utilisés. Nous avons utilisé pour la caractérisation desmatériaux de départ et des aérogels des techniques d'analyse telles que la diffraction des rayonsX (DRX), la BET, le MEB et le potentiel zêta. Nous avons également caractérisé les propriétésmécaniques des aérogels par des essais de compression et leurs propriétés de conductionthermique dans le régime non stationnaire par la technique du fil chaud. Il s’est avéré qu’unestructuration multi-échelles de ces différentes celluloses favorise la création de méso etnanoporosités au détriment de la macroporosité. Ceci favorise le confinement de l’air dans le bioaérogelpar effet de Knüdsen et améliore ses propriétés d’isolation thermique. D'autre part lesnanoparticules (organiques et inorganiques) permettent d'avoir des aérogels de très bonnespropriétés mécaniques. Le troisième objectif était d'essayer d'autres charges minérales (autres quela zéolithe) dans les différentes celluloses et d’explorer les propriétés morphologiques,structurales, thermiques et mécaniques. Cette étude a permis de montrer l'importance descaractéristiques morphologiques et géométriques des charges minérales dans le contrôle despropriétés physiques et mécaniques des aérogels bio-hybrides. / This thesis focuses on the preparation, using freeze drying technique, of aerogels madefrom cellulose and mineral fillers intended for potential use in the field of thermal insulation. Thefirst goal of this thesis was the characterization of different cellulose (cellulose (PBPD)nanocrystals (NCC) and oxidized nanofibrils (NFCs)), the inorganic filler (mainly zeolite) and theresulting aerogels prepared by various combinations. We used for the characterization of thestarting materials and the aerogels analytical techniques such as x-ray diffraction (XRD), BET,SEM and the zeta potential. We also characterized the mechanical properties of the aerogels bycompression tests and their thermal conduction properties in the non-steady state by the hot wiretechnique. It has been found that multi-scale structure of these celluloses promotes the creation ofmeso and nanoporosities to the detriment of macroporosity. This promotes the confinement ofthe air in the bio-aerogel by Knudsen effect and improves their thermal insulation properties. Onthe other hand, the nanoparticles (organic and inorganic) allow the aerogels to have very goodmechanical properties. The third objective was to try other mineral fillers (other than the zeolite)in combination with the different cellulose and explore the morphological, structural, thermaland mechanical of the corresponding aerogels. This study has allowed showing the importance ofmorphological and geometrical characteristics of the mineral fillers in controlling physical andmechanical properties of the bio-hybrid aerogels.

Orientador: Maurice de Koning / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-08-17T03:22:05Z (GMT). No. of bitstreams: 1 LandinezBorda_EdgarJosue_M.pdf: 6192602 bytes, checksum: b68b0a1398ca87f49a34034ae4473a58 (MD5) Previous issue date: 2010 / Resumo: Nesta dissertação abordamos o problema da escala temporal nas simulações atomísticas, focando no problema de eventos raros. A solução deste problema so e possível com o desenvolvimento de técnicas especiais. Especificamente, estudamos o método super-simétrico para encontrar caminhos de reação. Este metodo não apresenta as limitições comuns de outros metodos para eventos raros. Aplicamos o método a três problemas padrão e encontramos que o método permite estudar as transições raras sem precisar de um conhecimento detalhado do sistema. Além disso permite observar qualitativamente os mecanismos de transição / Abstract: This thesis deals with the problem of time scale in atomistic simulations, focusing on the problem of rare events. The solution to this problem is only possible with the development of special techniques. Specifically, we studied the super-symmetric method to find reaction pathways. This method does not have the usual limitations of other methods for rare events. We apply the method to three standard problems and find that the method allows to study the rare transitions without a detailed knowledge of the system. In addition, it allows us to observe qualitatively the transition mechanisms / Mestrado / Física Estatistica e Termodinamica / Mestre em Física

Lesões dentais por erosão têm sido cada vez mais presentes na prática clínica. A restauração direta com resina composta é uma das opções de tratamento para lesões severas, em que há comprometimento estético/funcional. Com o aprimoramento da tecnologia, a utilização do laser para pré-tratamento da superfície dentinária, antes do condicionamento ácido, tem sido considerada como método alternativo para melhorar a adesão das resinas compostas às superfícies erodidas. Assim, o objetivo deste estudo in vitro foi avaliar a influência da irradiação com laser de Er:YAG (2,94 ?m), de pulso super-curto, na adesão da resina composta à superfície dentinária erodida. Quarenta e seis discos de dentina foram obtidos a partir de 46 dentes terceiros molares humanos. A dentina oclusal planificada de 40 molares humanos teve metade de sua face protegida com fita UPVC (dentina hígida), enquanto na outra metade foi produzida uma lesão de erosão através da ciclagem em ácido cítrico (0,05 M, pH 2,3, 10 minutos, 6x/dia) e solução supersaturada (pH 7,0, 60 minutos entre os ataques ácidos). Metade das amostras foi irradiada com o laser de Er:YAG (50 ?s, 2 Hz, 80 mJ, 12,6 J/cm2) e a outra não (grupo controle). Em cada grupo de tratamento (laser ou controle) (n=10), um sistema adesivo autocondicionante foi utilizado e, então, confeccionados 2 cilindros de resina composta, tanto do lado erodido como no hígido (total de 4 cilindros), os quais foram submetidos à avaliação da Resistência de União através do ensaio de microcisalhamento (1 mm/min), após armazenamento em saliva artificial por 24 h. A análise do padrão de fratura foi realizada em microscópio óptico (40x). Por meio da Microscopia Eletrônica de Varredura (MEV), a morfologia das superfícies dentinárias hígida e submetida ao desafio erosivo, antes e após o tratamento com laser de Er:YAG (n=3), foi avaliada. Os valores obtidos de resistência de união (MPa) foram submetidos ao teste ANOVA e de comparações múltiplas de Tukey (p<0,05) e as análises das eletromicrografias foram feitas de forma descritiva. A análise morfológica da superfície mostrou alterações significativas na dentina hígida irradiada e na submetida à ciclagem erosiva, irradiada ou não. Quanto à resistência de união, houve diferença entre os 4 substratos analisados, sendo: dentina hígida irradiada (12,77±5,09 A), dentina hígida não irradiada (9,76±3,39 B), dentina erodida irradiada (7,62±3,39 C) e dentina erodida não irradiada (5,12±1,72 D). Houve predominância de padrão de fratura do tipo adesiva. Com base nos resultados e nos parâmetros de irradiação utilizados neste estudo, pode-se concluir que a erosão reduz a adesão em dentina e que o tratamento da superfície dentinária com laser de Er:YAG de largura de pulso super curta aumenta a adesão no substrato erodido ou hígido. / Dental erosion injuries have been increasingly present in clinical practice. Direct restoration with composite resin is one of the treatment options for severe injuries, where there is aesthetic/functional impairment. With the improvement of technology, laser-irradiation for pre-treatment of dentin before surface etching has been considered as an alternative method to improve the adhesion of composite resins to eroded surfaces. The objective of this in vitro study was to evaluate the influence of the irradiation with a super-short pulse Er:YAG (2.94 ?m) laser to the adhesion of composite resin to eroded dentin surface. Forty six dentin discs were obtained from 46 third molars. Forty samples of planned occlusal dentine, obtained from human molars, had half of their surface protected with plastic tape (sound dentin), while the other half was submitted to erosive cycles, consisted on immersion on citric acid (0.05 M, pH 2.3, 10 minutes, 6x/day) and supersaturated solution (pH 7.0, 60 minutes of acid attacks). Half of the samples was irradiated with the Er:YAG laser (50 ?s, 2 Hz, 80 mJ, 12.6 J/cm2) and the other was kept as control. In each treatment group (n = 10), a self-etching adhesive system was used and then two cylinders of composite resin were prepared, on both eroded and sound dentin (total of 4 cylinders). Microshear bond strength test was performed (1 mm/min), after 24 hours storage in artificial saliva. The analysis of the fracture pattern was determined by optical microscopy (40x). The morphology of sound and eroded dentin, before and after treatment with the Er:YAG laser (n = 3) was evaluated under Scanning Electron Microscopy (SEM). Bond strength values (MPa) were subjected to ANOVA and Tukey multiple comparisons test (p<0.05). The analyses of electron micrographs were made descriptively. Morphological analysis of the surface showed significant changes in irradiated and sound dentin subjected to erosive cycling. As for the bond strength, there were differences among the groups, as follows: sound dentin submitted to irradiation (12.77 ± 5.09 A), non-irradiated sound dentin (9.76 ± 3.39 B), eroded dentin submitted to irradiation (7 62 ± 3.39 C) and non-irradiated eroded dentin (5.12 ± 1.72 D). There was a predominance for the adhesive mode of failure. It was concluded that the erosion reduces the adhesion to dentin and that treating the dentin surface with a super-short-pulse Er:YAG laser increases adhesion to both eroded or sound dentin.

O Aço Inoxidável Super Duplex UNS S32760 é um aço de alta liga com estrutura composta por uma matriz ferrítica com ilhas austeníticas, em proporções aproximadamente iguais. Esta estrutura lhe confere boas propriedades como: resistência à corrosão, em particular à corrosão por pite e por fresta, excelentes propriedades mecânicas, boa soldabilidade, alta condutividade térmica, baixo coeficiente de expansão térmica e excelente tenacidade. Suas principais aplicações geralmente ocorrem em ambientes com alta concentração de cloreto, como por exemplo, em tubos para transporte de óleo e gás, equipamentos para transporte ou em contato com materiais rico sem cloretos, em tanques e vasos para a indústria química e petroquímica. Estas aplicações tornam importante a determinação da temperatura crítica de pite (TCP). A ASTM normatiza essa determinação com as normas G-150 e G-48, que abrangem aços inoxidáveis austeníticos comuns e ligas à base de níquel, não existindo uma condição especifica para o teste em aços super duplex. O objetivo deste trabalho é a caracterização eletroquímica e o desenvolvimento de uma metodologia para a determinação da temperatura crítica de pite de aços super duplex UNS S32760. Devido à falta de normatização para estes materiais uma combinação das normas ASTM G-48 e G-150 foi empregada neste trabalho. Utilizou-se como meio uma solução contendo FeCl3 6% e HCl 1%, em massa. Foram empregadas como técnicas medidas de potencial de circuito aberto em função do tempo de imersão, curvas de polarização potenciostática anódica, cronoamperometria, espectroscopia de impedância eletroquímica (EIE), microscopia ótica (MO), microscopia eletrônica de varredura (MEV) e espectroscopia por dispersão de energia (EDS). Foram realizados tratamentos dos dados experimentais, abordando-os de maneiras diferentes para que a melhor resposta fosse obtida na determinação da TCP das ligas. Duas amostras diferentes deste material foram estudadas, uma amostra comercial e uma amostra desenvolvida pelo laboratório de pesquisa e desenvolvimento da Villares Metals, com diferentes teores de cromo e molibdênio. Apesar da variação na composição química das amostras, nas análises por MEV e EDS, as mesmas se mostraram semelhantes, quando apenas polidas, apresentando os mesmos tipos de precipitado. A microscopia ótica possibilitou visualizar a diferença na proporção de fases entre as duas ligas e as características morfológicas das mesmas. Analisando mais detalhada e minuciosamente os dados eletroquímicos, foi determinado que o melhor valor de densidade de corrente a ser utilizada como parâmetro na determinação da TCP , é 25±5 &#181;Acm-2. Utilizando este parâmetro foi mostrado que a TCP determinada é menor, quando comparada com a obtida pelas normas convencionais. A combinação das diferentes técnicas permite afirmar que a metodologia empregada determina de maneira bem mais precisa a TCP. / UNS S32760 super duplex stainless steel is a high alloy steel, containing a ferrítica matrix and austenitic islands as structure at equal proportions approximately. This structure results in good properties as high resistance to corrosion, particularly to pitting and crevice corrosion, excellent mechanical properties, good weldability, high thermic conductivity, low thermic expansion coefficient, and excellent tenacity. Their principal applications are in high chloride concentration media, for example in tubes for oil and gas, in transport equipment when in contact with high chloride concentration materials, tanks and vases for chemical and petrochemical industries. Due to these applications the evaluation of the pitting critical temperature is mandatory for these materials. G-150 and G-48 ASTM Standards are recommended for conventional stainless steels and nickel alloys, but there is not any specific standard for super duplex stainless steels. The main of this work is the characterization and the development of a methodology to evaluate the critical pitting temperature for USS S32760 super duplex stainless steels. Due to the absence of standard analyses for this materials, a combination of G-48 and G-150 standards were employed. The medium was 6% FeCl3 by mass and 1% HCl by mass solution. Open circuit potential measurements, anodic potentiostatic polarization curves, chronoamperometry, electrochemical impedance spectroscopy (EIS), optical microscopy (OM), scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS) were used as techniques. Different treatments for the experimental results were used in order to obtain the best value for TCP of these alloys. Two different samples of this material were studied: a commercial sample and a new composition developed at P&D Villares Metals industry, with different contents in chromium and molybdenum. The materials studied presented the same kinds of inclusions, according to SEM and EDS analyses. OM analysis showed the proportionality between the ferritic and austenitic phases and their morphological characteristics. The electrochemical studies suggest the 25 ± 5 &#181;Acm-2 value for current density to be used in the CPT e valuation. The CPT obtained is lower when compared to those one using conventional standards. The combination of different techniques permits to conclude that the proposed methodology evaluates the CPT w ith higher precision.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-06-01T14:51:47Z No. of bitstreams: 1 mariadeoliveirabarracosta.pdf: 8045156 bytes, checksum: 4f6ed59e9077758a07401e7775d6589e (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-06-02T15:56:18Z (GMT) No. of bitstreams: 1 mariadeoliveirabarracosta.pdf: 8045156 bytes, checksum: 4f6ed59e9077758a07401e7775d6589e (MD5) / Made available in DSpace on 2017-06-02T15:56:18Z (GMT). No. of bitstreams: 1 mariadeoliveirabarracosta.pdf: 8045156 bytes, checksum: 4f6ed59e9077758a07401e7775d6589e (MD5) Previous issue date: 2017-02-16 / I Mostra de Juiz de Fora do Cinema Super 8, de 1979, como síntese de um momento de ruptura no país, em que havia: abertura política, que levou ao fim da ditadura civil-militar; nova tecnologia do Super 8 (a indústria cria um equipamento que permite mudança na linguagem cinematográfica); e emergência do jovem como sujeito contestador e, portanto, provocador de mudanças sociais. Foi desenvolvida uma análise dos filmes apresentados no evento e as respectivas influências na construção das narrativas cinematográficas amadoras idealizadas por esses jovens, no final dos anos 1970. A pesquisa bibliográfica compreende estudos sobre memória e arquivo, com autores como Michael Pollak, Andreas Huyssen, Paul Thompson, Pierre Nora, Jacques Le Goff e Verena Alberti. Sobre o movimento superoitista, Flávio Rogério Rocha, John David Beal, P. Dargy e N. Bau foram essenciais. A pesquisa utiliza a metodologia da história oral, e, por meio do depoimento de cinco participantes da mostra, busca reconstituir o clima da época e a relação dos realizadores com o cinema. Tais relatos são complementados pela pesquisa documental, executada em acervos públicos e pessoais, e que se constitui em matérias jornalísticas, documentos da época e os filmes (poucos deles digitalizados atualmente) exibidos durante o evento. Entre os diretores, foi possível perceber que muitos começaram a filmar pela necessidade de expor suas ideias, e o Super 8, mais barato e de fácil manuseio, mostrou-se o formato ideal para tal fim. / The I Mostra de Juiz de Fora do Cinema Super 8, from 1979, as a synthesis of a moment of rupture in the country, where there was: political opening, which led to the end of the civilmilitary dictatorship; new technology from the Super 8 (the industry creates a device that allows to change the cinematographic language); the emergency of the youth as an answering subject and therefore a provocateur of social change. Analysis of the films in the event and the respective influences in the construction of amateur cinematographic narratives idealized by these young people in the late 1970s. The bibliographic research includes studies on memory and archives, with authors such as Michael Pollak, Andreas Huyssen, Paul Thompson, Pierre Nora, Jacques Le Goff and Verena Alberti. On the superoitist movement, Flávio Rogério Rocha, John David Beal, P. Dargy and N. Bau were essential. The research uses oral history methodology, and, through testimonial of five participants of the festival, seeks to reconstitute the climate of the time and the relationship of filmmakers with cinema. These reports are complemented by the documentary research, executed in public and personal collections, and that are constituted in journalistic matters, documents of the time and the films exhibited during the event. Between the directors, it was possible to realize that many of them became to film to expose their ideas, and the Super 8, cheaper and easy handling, proved to be the ideal format for that purpose.

Un membre de la famille des tétraspanines, CD82, est une protéine transmembranaire et l'un des rares suppresseurs de métastase identifié jusqu'à présent. Cependant, le mécanisme de suppression de métastase induite par CD82 reste mal compris. Les tétraspanines, y compris CD82, ont la propriété unique de créer un réseau d'interactions protéines-protéines à la membrane plasmique, appelé « tetraspanin web ». Dans ce réseau, CD82 est connu pour interagir avec d’autres tétraspanines, y compris CD9, CD81 et CD151, en plus d’autres protéines membranaires telles que les intégrines, les récepteurs de facteurs de croissance et les protéines de type immunoglobuline. De plus, des travaux antérieurs ont identifié que l'interaction de CD82 avec l’EGFR, d'autres tétraspanines et les intégrines dépend de l'expression des gangliosides au sein de la membrane plasmique.À ce jour, les études dans ce domaine ont utilisé des techniques d'ensemble qui ne peuvent pas tenir compte de la dynamique et de la stochasticité de la membrane, alors qu'il est maintenant bien établi que l'organisation spatio-temporelle de ses composants est cruciale pour certaines fonctions cellulaires.Ainsi, lors de ma thèse de doctorat, j'ai cherché à étudier à la fois la dynamique et la compartimentation de CD82 et de ses partenaires à la membrane plasmique des cellules épithéliales mammaires HB2. Pour ce faire, la technique de pistage en molécule unique basée sur l’utilisation d’un microscope TIRF a été utilisée afin d’obtenir des informations directes à l'échelle nanométrique sur la dynamique de protéines individuelles dans les cellules vivantes. Nos expériences en pistage de molécule unique ont démontré que l'expression de CD82 augmentait la dynamique CD81 à la membrane plasmique des cellules HB2 et modifiait ses interactions au sein du tetraspanin web. En revanche, les dynamiques de CD9 et de l’intégrine α3 n'ont pas été modifiées par l'expression de CD82. De plus, en modifiant enzymatiquement l'expression des gangliosides, nous avons montré que ces lipides sont impliqués à la fois dans la dynamique et la compartimentation des tétraspanines à la membrane plasmique. En effet, la déplétion en gangliosides entraine une augmentation de la dynamique de CD82, CD81 et de l’intégrine α3 ainsi qu'une redistribution des tétraspanines à la membrane plasmique. Nous avons également étudié la migration en 2D des cellules HB2 et montré que CD82 et les gangliosides modifiaient de façon différentielle la migration des cellules HB2.L’ensemble de nos résultats démontrent que CD82 et les gangliosides modulent de manière différente la dynamique et la compartimentation des tétraspanines et de leurs partenaires à la membrane plasmique des cellules HB2. Enfin, ce travail suggère que l'activité de CD82 en tant que suppresseur de métastase pourrait être en partie liée à sa capacité, en coopération avec les gangliosides, à moduler l'organisation spatio-temporelle de ses partenaires au sein du tetraspanin web. / A member of the family of tetraspanins, CD82, is a transmembrane protein and one of the rare metastasis suppressors identified so far. However, the mechanism of CD82-induced metastasis suppression remains not fully revealed. Tetraspanins, including CD82, have the unique property to create a network of protein-protein interactions within the plasma membrane, called tetraspanin web. Within this network, tetraspanins interact with each other (eg. CD82 with CD9, CD81 and CD151) as well as with other proteins, such as: integrins, growth factor receptors and immunoglobulin-like proteins. Additionally previous work has identified that the interaction of CD82 with EGFR, other tetraspanins and integrins depends on the expression of gangliosides at the plasma membrane.To date, studies in this field have employed ensemble-averaging techniques which are unable to account for membrane dynamics and stochasticity. Nevertheless, it is now well established that the spatio-temporal organization of its components is crucial for cellular functions.Thus, during my PhD thesis I aimed to study both the dynamics and partitioning of CD82 and its partners at the plasma membrane of HB2 mammary cells. To achieve this aim, a TIRF-based Single Molecule Tracking (SMT) approach was employed to provide direct nanoscale insights by observing individual proteins in living cells. Our SMT experiments demonstrated that CD82 overexpression increased CD81 dynamics at the plasma membrane of HB2 cells and modified its interaction within the tetraspanin web. In contrast, CD9 and α3 integrin dynamics were not modified by CD82 expression. Moreover, by enzymatically tuning gangliosides expression, we showed that these lipids are involved in both dynamics and partitioning of tetraspanins at the plasma membrane. Indeed, gangliosides depletion resulted in an increase in CD82, CD81 and α3 integrin dynamics as well as a redistribution of tetraspanins at the plasma membrane. We also investigated the 2D migration of HB2 cells showing that CD82 and gangliosides differentially altered the cellular migration of HB2 cells.Taken together, our results demonstrate that both CD82 and gangliosides differentially modulate the dynamics and partitioning of tetraspanins and their partners at the plasma membrane of HB2 cells. Finally, this work suggests that CD82 activity as metastasis suppressor could be in part linked to its ability, in cooperation with gangliosides, to modulate the spatio-temporal organization of its partners within the tetraspanin web.

Le but de ce travail de thèse est de développer des aérogels biosourcés, mécaniquement résistants et thermiquement très isolants (voire super-isolants). Les aérogels à base de cellulose, souvent appelés « aérocelluloses », sont connus pour être très poreux et extrêmement légers. Ils présentent en revanche une grande dispersion de tailles de pores, donnant de propriétés thermiques relativement modestes. Nous avons étudié plusieurs approches pour améliorer la morphologie des aérocelluloses: la modification du solvant, la réticulation chimique de la cellulose et la formation d'hybrides avec d'autres polymères. La réticulation de la cellulose a réellement permis d'affiner la structure poreuse de l'aérocellulose vers une nano-structuration ce qui a amélioré la conductivité thermique, s'approchant du domaine de la super-isolation (0.026 W.m-1.K-1). Un autre polysaccharide, la pectine, a été utilisé pour préparer un aérogel également poreux et très léger, « l'aéropectine ». L'aéropectine et l'aérocellulose présentent de fortes similitudes dans leur morphologie. Cependant, l'aéropectine possède de meilleures propriétés thermiques, super-isolantes (0.020 W.m-1.K-1), grâce à la nano-structuration du réseau poreux. Ces aérogels sont 100% biosourcés avec un faible impact environnemental, et sont très prometteurs non seulement pour l'isolation thermique mais également pour de nombreuses autres applications, telle que la libération contrôlée de médicaments ou la catalyse. La formation d'aérogel de silice à l'intérieur de la structure poreuse d'aéropectine a augmenté la surface spécifique jusqu'à 700 m2/g et a permis de diminuer la conductivité thermique (0.017 W.m-1.K-1). / The work aims at developing a new generation of bio-based aerogels, mechanically robust and thermally very insulating (super-insulating). Cellulose aerogels, called “aerocelluloses”, are known to be very porous and ultra-lightweight materials but present a wide range of pores and therefore moderate thermal insulating properties. We studied several approaches for tuning aerocellulose towards a finer and nanostructured morphology: modification of solvent, cellulose crosslinking and formation of cellulose-based hybrids. It was cellulose cross-linking that greatly improved aerocellulose structure towards a nano-structuration, reflected by the increase of specific surface area and the decrease of thermal conductivity, close to super-insulation (0.026 W.m-1.K-1). Another polysaccharide, pectin, was used for preparing a highly porous and very lightweight aerogel called “aeropectin”. Aeropectin and aerocellulose were compared; they present many similarities in their morphology. However, aeropectin has better thermal properties, reaching super-insulation (0.020 W.m-1.K-1). These bio-aerogels are 100% bio-based, environmentally friendly and present a high potential not only for thermal insulation but also for a broad range of other applications such as controlled drug release and catalysis. The formation of silica aerogel directly inside the porous structure of aeropectin increased the specific surface area up to 700 m²/g and decreased thermal conductivity (0.017 W.m-1.K-1).