L’objectif de cette thèse est de proposer des schémas de pondérations alternatives visant à prendre en compte le risque dans la construction d’indices obligataires. Nous partons du constat suivant : les indices obligataires qui existent sur le marché sont pondérés en fonction de la capitalisation des émetteurs. L’implication n’est pas négligeable, dans la mesure où utiliser cette approche implique de sur-pondérer les entités les plus endettées. Sur cette base, nous proposons dans le premier chapitre de pondérer les entreprises au sein de l’indice en fonction de leur solvabilité. Dans le deuxième chapitre, toujours sur l’univers des obligations d’entreprises, nous appliquons le principe du risque en parité. Plus précisément, les secteurs sont pondérés de façon inversement proportionnelle à une mesure du risque de crédit innovante : la Duration Times Spread. Enfin, le dernier chapitre s’intéresse à l’application de cette même technique du risque en parité, mais cette fois-ci à l’univers des obligations souveraines. Nous nous engageons dans la modélisation d’une structure de taux à terme, permettant de mesurer le risque de taux d’intérêt dans un contexte global. Plus généralement, nous démontrons que ces pondérations alternatives, qui intègrent une notion de risque (crédit ou taux) et s’éloignent ainsi du pur aspect “niveau d’endettement”, fournissent une nouvelle grille de lecture pour la compréhension de la dynamique des marchés obligataires ainsi que des améliorations significatives dans le profil rendement-risque. / In this thesis, we are keen to explore alternative weighting schemes that account for risk in the fixed-income indexing market. We start with the following observation: bond indexes that exist on the market are generally cap-weighted. The implication is not trivial: when holding such index, an investor is exposed to the most indebted issuers. From that standpoint, in the first chapter we make the proposal to consider an issuer’s creditworthiness as a weighting metric. Then in the second chapter, still working on the corporate bond market, we decide to turn to risk-parity indexing. More precisely, sectors are weighted inversely proportional to an innovative credit risk measure. Finally, the third chapter is devoted to the transposition of such risk-based philosophy to the sovereign bond universe. Particularly, we examine term structure modeling to appraise interest rate risk in a global framework. On a more general note, we show that these alternative indexing schemes - that do not emanate from pure indebtedness, but that are rather based on more sensible definitions of risk (credit or interest rate) provide a new reading grid for understanding bond market’s dynamics as well as appealing improvements in the indexes’ risk-return profile.

Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2017-11-23T14:03:34Z No. of bitstreams: 1 PDF - Paulo Henrique Freitas Silva.pdf: 42823648 bytes, checksum: 5039836455fff1766f55b2b0e0ef154b (MD5) / Approved for entry into archive by Secta BC (secta.csu.bc@uepb.edu.br) on 2017-12-06T18:43:49Z (GMT) No. of bitstreams: 1 PDF - Paulo Henrique Freitas Silva.pdf: 42823648 bytes, checksum: 5039836455fff1766f55b2b0e0ef154b (MD5) / Made available in DSpace on 2017-12-06T18:43:49Z (GMT). No. of bitstreams: 1 PDF - Paulo Henrique Freitas Silva.pdf: 42823648 bytes, checksum: 5039836455fff1766f55b2b0e0ef154b (MD5) Previous issue date: 2017-05-04 / This work has objective identify how is the teaching and learning of fractions in the classroom and researches, and what the approximations between classrooms and researches. For this, were analyzed researches about the fractions theme and informations provided by 25 elementary school teachers, collected through an open questionnaire composed for 10 questions. The data collected are of the qualitative type and were analyzed according to the method qualitative research, in a Discurso do Sujeito Coletivo approach. All the research analyzed in this work, when they propose activitys about the fractions theme, they show, directly or indirectly, that is important to work this theme with others representations - like geometrics figures and manipulables materials - beyond of fractional bar notation, for the students understand this content. Beyond this, the searchers shows alternatives for decrease the problems cited in the literature, like lack of attention and difficulties of understand the equivalence and comparation ideas, and operations with fractions. They also affirm that, in classroom, there are a preocupation with memorization of formulas and procedures and correct answer, too, but this does not necessaryli imply in understanding to conteude studed. This shows a distance between classroom and the researches, since the researches, usually, they propose alternatives and discussions whose main focus is a concern in learning with understand of the fraction theme. / Este trabalho tem como objetivo identificar como tem sido o ensino-aprendizagem de frações na sala de aula e nas pesquisas, e quais as possíveis aproximações das pesquisas com a sala de aula. Para isso, foram analisadas pesquisas sobre o referido tema e analisados dados fornecidos por 25 professores do Ensino Fundamental, que foram levantados por meio de um questionário aberto composto por 10 perguntas. Os dados obtidos são do tipo qualitativo e foram analisados conforme o método qualitativo de pesquisa, na abordagem do Discurso do Sujeito Coletivo (DSC). Todas as pesquisas analisadas neste trabalho, quando propõem atividades sobre o tema frações, mostram, direta ou indiretamente, que é importante trabalhar com outras representações de frações, como figuras geométricas e materiais manipuláveis - além da notação barra-fracionária - para que os alunos possam compreender esse conteúdo. Além disso, os pesquisadores mostram alternativas para amenizar problemas citados pela literatura, como falta de atenção e dificuldade para compreender as ideias de equivalência, comparação e operações com frações, e afirmam que em sala de aula há uma preocupação mais voltada para a memorização de fórmulas e de procedimentos e também com a resposta correta, o que não implica, necessariamente, em compreensão do conteúdo estudado. Isso evidencia um distanciamento da sala de aula e as pesquisas, já que essas, geralmente, trazem alternativas e discussões cujo foco principal é a promoção de uma aprendizagem com compreensão desse conteúdo.

Este estudo buscou elucidar os fatores que influenciam na opção dos agricultores familiares de Capanema e Planalto (PR) em produzir e/ou deixarem de produzir tabaco e a implicação destas escolhas, em seus meios de vida. Chama a atenção o fato de o Brasil ser atualmente o maior exportador e o segundo maior produtor de tabaco do mundo sendo a região sul do país, a responsável por concentrar aproximadamente 95% da produção nacional, permitindo a manutenção de muitas famílias que possuem pequenas áreas de terra ou que não possuem terras próprias no meio rural. Capanema e Planalto localizam-se na região sudoeste do Paraná, que se destaca por cultivar espécies de fumo de galpão, que exige manejo, colheita, secagem e classificação diferenciadas do fumo de estufa. Essas particularidades podem proporcionar ao fumicultor a possibilidade da não especialização, buscando alternativas que o auxiliem a se manter no campo e até mesmo, substituir o cultivo do tabaco por outra atividade com o passar dos anos. Nessa perspectiva, optou-se por entrevistar fumicultores e ex-fumicultores - que por motivos variados tenham encontrado alternativas ao cultivo do tabaco, por conta própria ou com auxílio de organizações governamentais e não-governamentais, - buscando compreender de maneira geral como o tabaco está inserido nas propriedades da região e quais estratégias vêm sendo realizadas pelas famílias que optam pelo não cultivo do tabaco. Para tanto, realizou-se um estudo comparativo com auxílio de métodos de caráter qualitativo e quantitativo via aplicação de um formulário e a realização de entrevista pré-estruturada com quarenta e duas famílias. Os resultados encontrados revelam que em média, os exfumicultores apresentam leve superioridade nos índices de sustentabilidade e diversificação, a maioria tendo realizado mudanças favoráveis em seus meios de vida. Verificou-se também que os ex-fumicultores deixam de cultivar o tabaco por fatores que vão além da renda familiar. Dentre esses fatores, destaca-se o uso excessivo de agrotóxicos, a necessidade de mão-de-obra e a renda com o tabaco, que geralmente é inferior à expectativa do fumicultor. / This study aimed to elucidate the factors which influence family farmers from Capanema and Planalto (PR) to start and stop producing tobacco and the implication of these choices in their livelihoods. It attracts our attention to the fact that Brazil is the largest tobacco exporter and the second largest tobacco producer in the world, and the South region, which concentrates approximately ninety-five percent of the national production, making it possible to supply a lot of farmers who own small land areas or even those who do not actually own their piece of land. Capanema and Planalto are located in the Southeast region of the state of Paraná which stands out for growing barn tobacco, which requires management, harvesting, drying and a different classification from greenhouse tobacco. These particularities may be in favor of the tobacco growers to allow the non specialization, searching for alternatives that help them keep in the country and even change from tobacco producing to another activity over the years. In this perspective, it was chosen to interview active and former tobacco growers who, for many reasons, have found other alternatives to tobacco growing, by themselves or with the help of governmental organizations and NGOs, trying to understand in general how it is inserted in the properties of the region and which strategies are being used by families who choose not to grow tobacco. For this, a comparative study was held with the help of methods of quantitative and qualitative characters via an application form and the accomplishment of a pre-structured interview with forty-two families. The obtained results reveal that in average, the former tobacco growers show slight superiority in sustainability and diversification indexes, most of them having made favorable changes in their livelihoods. It was also checked that the former tobacco growers stop growing tobacco for factors that go beyond family income. Among these factors, the overusing of pesticides is highlighted, the need of manpower and the income with tobacco, which is generally less than expected by the farmer. But the production strategies found by former tobacco growers to replace tobacco in the farms vary between chicken and pork creation in integration system, construction of agro-industries and sale of homemade products directly to the consumer, apart from agricultural and nonagricultural work performed outside the production units.

O presente estudo refere-se a uma investigação qualitativa, do tipo etnográfica, voltada para a identificação e compreensão das assim chamadas alternativas pedagógicas e pessoais dos professores de educação física da RME/POA. Nesta investigação busquei respostas para o seguinte problema de pesquisa: o que os professores de educação física da RME/POA têm feito na prática pedagógica e de vida pessoal para evitar o desgaste e o esgotamento em função das circunstâncias de trabalho num contexto de mudanças sócio-culturais? Sendo assim, o objetivo deste estudo foi identificar e compreender as alternativas pedagógicas e pessoais destes professores para evitar, superar e amenizar o desgaste ocasionado pelo trabalho docente. Para fins de entendimento, neste estudo o que denominei como alternativas pessoais foram tomadas somente como medida de influência ao trabalho pedagógico, pois não foi objetivo deste estudo entrar nas histórias pessoais de vida dos professores-colaboradores. Os procedimentos e instrumentos de obtenção de informações para desenvolver este estudo foram: a observação participante, a entrevista semi-estruturada, diário de campo e análise de documentos. O trabalho de campo teve um tempo total de duração de dez meses, dos quais oito meses foram de contato com os professores-colaboradores, e dois meses foram de pesquisas dedicadas exclusivamente para análise de documentos e referencial bibliográfico. Como parte de minhas opções metodológicas, durante a investigação no campo decidi trabalhar com duas escolas e seis professores-colaboradores, a fim de garantir a representatividade tipológica. A partir das informações produzidas no campo foi possível a construção das três categorias de análise deste estudo: a primeira, a reorganização do trabalho docente; a segunda, a dupla face do vínculo e o diálogo; a terceira, a trajetória nas alternativas dos professores. / The present study refers to a qualitative inquiry, of the ethnographic kind, towards the comprehension and identification of the so-called alternative pedagogical and personals of the professors of the RME/POA. In this inquiry I searched for the following problem of research: what the professors of physical education of the RME/POA have deed in the practical pedagogical one and of personal life for avoid the stress and the exhaustion in function of the circumstances of work in a context of partner-cultural changes? Therefore, the objective of this study was identify and understand the pedagogical and personal alternatives of these professors to a void, surpass and minimize the stress caused by the educational work. For ends of understanding, in this I study what did I name like personal alternatives was taken only as measure of influence to the pedagogical work, once the objective of this study was not to go through personal backgrounds of life of the professors-collaborating ones. The procedures and information instruments to obtain the development of this study were: the participant observation, the interview is structured, newspaper of field and analysis of documents. The fieldwork had a total time of duration of ten months, of the which eight months were of contact with the professors-collaborating, and two months were of researches dedicated exclusively to documents analysis and bibliographical yardstick. As part of my methodological options, during the field inquiry in the field I decided to work with two schools and six collaborating professors, to guarantee the typological representative. From the information it was possible the construction of the three categories of analysis of this study: first, the reorganization of the educational work; to second, to double face of the bond and the dialogue; to third, the path in the alternatives of the professors.

Increasing global demand for energy, supplied primarily by polluting sources, generates severe environmental impacts. Buildings consume approximately 37 percent of total global energy, during the construction phase in the form of embodied energy and during the operation phase as operating energy. In Uruguay, current policies for energy efficiency are focused specifically on operational energy. On that basis, the present study intended to perform an energy analysis to assess the significance of embodied energy of a multi storied building in Uruguay compared to parameters of operational energy, and analyze traditional constructive alternatives in the most significant items. The methodology consisted of a process analysis on a selected building to calculate its initial embodied energy. Then recurrent and final embodied energy were estimated and on site collection of data was performed to assess operational energy, in the framework of a life cycle energy analysis. The survey included data on energy consumed by users for their own vehicles operation, which was used as a comparative parameter. Embodied energy was then compared to operational energy and energy payback period was calculated. Typical constructive alternatives were proposed for reinforced concrete structure and brick masonry. Initial embodied energy of alternatives was computed, and its impact on total embodied energy was assessed. Embodied energy values proved to be significant when compared with operational energy. Results showed that embodied energy was equivalent to about nineteen years of operation of the building, and twenty one years of users’ own vehicles fuel consumption. It was also concluded that the proposed alternatives for the structure did not represent a significant reduction, while for masonry meant a substantial decrease in total embodied energy. Finally lines of work were suggested for estimating carbon dioxide emissions derived from embodied energy, as well as for national data generation on materials energy intensities and materials replacement rates over the life of buildings, in order to improve life cycle energy analysis. / La creciente demanda a nivel mundial, de energía proveniente en gran medida de fuentes contaminantes, general un severo impacto ambiental. Las edificaciones consumen aproximadamente el 37 por ciento de la energía global total, durante su construcción en la forma de energía incorporada y durante su operación como energía operacional. En Uruguay, las actuales políticas de eficiencia energética están enfocadas específicamente hacia la energía operacional. En función de ello, el presente trabajo se propuso realizar un análisis energético para evaluar la relevancia de la energía incorporada en un edificio en altura en Uruguay en relación con su energía operacional, y analizar alternativas constructivas tradicionales en los rubros más significativos. La metodología consistió en desarrollar un análisis de proceso en una edificación seleccionada para calcular su energía incorporada. Se estimaron luego su energía incorporada recurrente y final, y se realizó un levantamiento de datos en el sitio, a fin de determinar la energía operacional, en el marco de un análisis energético de ciclo de vida. La encuesta incluyó información sobre la energía consumida por los usuarios en la operación de vehículo propio, la cual se utilizó como parámetro de comparación. Se comparó la energía incorporada con la energía operacional y se analizó el período de retorno energético. Se propusieron alternativas constructivas para la estructura de hormigón armado y para la mampostería de ladrillo. Se calculó la energía incorporada inicial de las alternativas propuestas, y se evaluó su incidencia en la energía incorporada total. Los valores de energía incorporada inicial demostraron ser relevantes al compararlos con la energía operacional, resultando equivalentes a aproximadamente diecinueve años de operación del edificio, y a veintiún años de consumo de combustible en vehículos propios. Se concluyó asimismo que las propuestas realizadas para la estructura representan una reducción poco significativa, en tanto que las alternativas calculadas para la mampostería fueron relevantes para la disminución de la energía incorporada total. Finalmente se sugieren líneas de trabajo para la determinación de las emisiones de dióxido de carbono derivadas de la energía incorporada, así como la generación de datos a nivel nacional sobre índices energéticos y de tasas de reposición de materiales a lo largo de la vida útil de los edificios, a fin de mejorar los análisis de ciclo de vida energéticos.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2016-09-12T15:12:26Z No. of bitstreams: 2 Dissertação - Adriano Henrique de Oliveira Afonso - 2016.pdf: 2284681 bytes, checksum: 4a651ec7c13331f5ad44ba0890321498 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-09-12T15:12:58Z (GMT) No. of bitstreams: 2 Dissertação - Adriano Henrique de Oliveira Afonso - 2016.pdf: 2284681 bytes, checksum: 4a651ec7c13331f5ad44ba0890321498 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-09-12T15:12:58Z (GMT). No. of bitstreams: 2 Dissertação - Adriano Henrique de Oliveira Afonso - 2016.pdf: 2284681 bytes, checksum: 4a651ec7c13331f5ad44ba0890321498 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-08-12 / This dissertation aims to analyze the conflictual in agrarian reform settlements on home territory and demonstrate the viability of alternative forms of access to justice , delimiting social and legal measures to this desideratum. In our country the agrarian reform is essentially an outstanding issue of final settlement, delayed for centuries, conducted in the last decades with more social approach, but still deficient in its implementation. Despite having your trigger the pressure of social movements, the national agrarian reform program is conducted by the Government, in a context essentially charged of tension and violence, in which the Brazilian government, based in the capitalist mold, aiming to serve the interests the established powers and the agrarian oligarchies is shown unable to respond to agrarian conflicts with a focus on social justice. In this sense, at first, we trace the history of the Brazilian agrarian training, legislative developments and situation in the current context. In sequence, will be analyzed the conflictual field and violence resulting therefrom, both real and symbolic and the inability of the criminal justice system and Brazilian prison responding to the occurrence of the offense on the field. Finally, it will be analyzed as has materialized the action - or inaction - of the public authorities in the field, to facilitate access to justice to the settlers peasants, analyzing the role of the main state institutions involved and the most effective alternatives to implement alternatives solutions to reduction of agrarian conflicts. / Esta dissertação almeja analisar a conflituosidade nos assentamentos de reforma agrária em território pátrio e demonstrar a viabilidade de formas alternativas de acesso à justiça, delimitando medidas sociais e jurídicas para esse desiderato. Em nosso país, a reforma agrária é essencialmente uma questão pendente de solução definitiva, adiada por séculos, conduzida, nas últimas décadas, com enfoque mais social, mas ainda deficitária em sua execução. Em que pese ter seu estopim pela pressão dos movimentos sociais, o programa de reforma agrária nacional é conduzido pelo poder público, em um contexto essencialmente carregado de tensão e violência, no qual o Estado brasileiro, alicerçado sob o molde capitalista, objetivando atender os interesses dos poderes instituídos e das oligarquias agrárias, mostra-se incapaz de responder aos conflitos agrários sob o enfoque da justiça social. Nesse sentido, em um primeiro momento, traçamos o histórico da formação agrária brasileira, da evolução legislativa e a situação do contexto atual. Na sequência, analisa-se a conflituosidade no campo e a violência dela decorrente, tanto real como simbólica, bem como a incapacidade do sistema penal e carcerário brasileiro de responder à ocorrência do delito no campo. Finalmente, será analisada como tem se materializado a atuação – ou a omissão – do poder público no campo para viabilizar o acesso à justiça aos assentados, analisando o papel das principais instituições estatais envolvidas e as alternativas mais eficazes para implementar soluções alternativas para redução dos conflitos agrários.

Neste trabalho, avaliou-se a queima do sebo bovino por meio de uma fornalha calorimétrica flamotubular instrumentada que opera à pressão atmosférica. Como parte do trabalho experimental, foram analisadas as curvas de rendimento térmico da queima do combustível, sebo bovino, e verificou-se seu comportamento quanto à transferência de calor e emissão de gases. Experimentalmente, a fornalha calorimétrica foi remodelada e adaptada para operar com sebo bovino, incorporando-se a esta um elemento de aquecimento prévio, trata-se de um queimador desenvolvido no NETeF possuindo um sistema de alimentação com aquecimento para o combustível, já que o sebo se encontra no estado sólido a temperatura ambiente. O queimador utilizado no experimento foi do tipo misto. Os resultados das medições do poder calorífico do sebo bovino mostraram-se altos: 39.985,5 kJ/kg (dados obtidos no laboratório do NETeF), fazendo com que o sebo se torne uma fonte menos poluente. / In this study, we evaluated the burning of tallow by a calorimetric flamotubular instrumented furnace which operates at atmospheric pressure. As part of the experimental work, the curves of thermal efficiency of fuel combustion (beef tallow) were analyzed, and it was possible to set their composition toward the transfer of heat and gas emissions. Experimentally, the calorimetric furnace was remodeled and adapted to operate with beef tallow by incorporating an element of this preheating, it is a burner developed in NETeF and it has a system to supply heating for fuel, as the tallow is solid at room temperature. The burner used in the experiment was of mixed type. The results of measurements of the calorific value of beef tallow were shown to be high: 39985.5 kJ/kg (data obtained in the laboratory of NETeF), causing the fat to become a viable source.

A definição da localização de um empreendimento é uma das principais decisões que determinará a magnitude e a importância de grande parte dos impactos ambientais negativos resultantes de sua instalação e operação. Porém, é visto que a dimensão ambiental normalmente não está presente nas análises de localização do projeto que ocorrem previamente ao licenciamento ambiental, levando-se em consideração apenas as dimensões técnicas e econômicas. Um dos motivos atribuídos a esta ausência é que normalmente não existem ou não estão disponíveis informações ambientais de natureza secundária que revelem restrições territoriais para a localização do empreendimento previamente ao processo de licenciamento ambiental, sendo normalmente produzidas posteriormente durante a elaboração do estudo ambiental dentro do processo de avaliação de impacto ambiental. Neste sentido, o presente trabalho tem como objetivo principal analisar as possibilidades para o estabelecimento de uma base referencial de informações sobre potencialidades e restrições ambientais e territoriais como suporte ao estudo de alternativas de traçados rodoviários, previamente ao início do processo formal de avaliação de impacto ambiental e de licenciamento ambiental do projeto. Para isso, foram identificados quais são os principais fatores territoriais necessários à análise prévia de viabilidade ambiental de traçados rodoviários, utilizando-se como estudo de caso do trecho sul do Rodoanel Mário Covas, na região metropolitana de São Paulo. Foram aplicadas técnicas de geoprocessamento para trabalhar os dados encontrados e assim, foram produzidas três diretrizes de traçado a partir das restrições ambientais, as quais foram discutidas junto da potencialidade do território, identificando alterações que podiam ter sido feitas no traçado construído da rodovia. As discussões mostram que, ainda que existam certos limites (como a padronização dos dados trabalhados e a escala trabalhada), é possível compatibilizar potencialidades e restrições territoriais ambientais na concepção de alternativas de localização, previamente ao processo de licenciamento ambiental, para o caso de empreendimentos rodoviários. / Defining the location of an enterprise is one of the key decisions that determine the importance of the negative environmental impacts resulting from its installation and operation. But, the environmental dimension is not normally present in the analysis of location of the project that occur before the environmental licensing, considering only the technical and economic aspects. One reason for this is the fact that the environmental information of a secondary nature, which reveals territorial restrictions to the location of the project, is not available or are not systematized and available for this preliminary analysis, and it is usually produced later during the preparation of the environmental statement within the process of environmental impact assessment. In this sense, this work aims to analyze the possibilities for setting a reference base of information on environmental and territorial potential and restrictions, as a support for the study of alternative road designs, prior to the environmental impact assessment and environmental licensing of the project. For this, the main territorial factors, necessary for investigating the environmental analysis of road layouts viability were identified, using as a case study of the southern section of the Rodoanel Mario Covas in the metropolitan region of Sao Paulo. Geoprocessing techniques were applied to work the found data, and then, three road designs guidelines were produced from the environmental restrictions, which were discussed with the territorial potential, identifying changes that could have been made in the constructed road layout. The discussions show that, although that are limits (as standardization of the discussed data and the worked scale), is possible to reconcile the territorial environmental potential and restrictions in the concept of road designs, prior to the licensing process for the case of road projects.

Contrairement à la vision classique des ARNms eucaryotes qui ne contiendrait qu’une seule séquence codante, de nombreuses évidences expérimentales montrent que ces ARNms contiennent plusieurs séquences codantes qui permettraient l’expression de plusieurs protéines différentes. Les ARNms sont donc multicodants et contiennent des cadres de lectures alternatifs (AltORFs pour alternative open reading frames). Ces ORFs alternatifs sont présents dans les régions non-traduites (UTRs) ou chevauchant le RefORF (cadre de lecture ouvert de référence) dans les cadres de lectures non-canoniques +2 et +3. Le protéome est donc plus complexe que ce que l’on pense. Toutefois, le rôle et la fonction de ces nouvelles protéines restent à être investigués. Au cours de mon projet de recherche à la maîtrise, j’ai commencé la caractérisation de la protéine alternative AltMiD51, codée dans le 5’UTR du gène bicistronique MIEF1/SMCR7L/MID51 et co-exprimée avec sa protéine de référence MiD51. Par des approches variées de biologie moléculaire, cellulaire et biochimique, j’ai d’abord démontré et confirmé la localisation cellulaire de la protéine AltMiD51 à la mitochondrie. Par la suite, j’ai pu démontrer que la présence d’AltMiD51 affecte significativement la morphologie mitochondriale en fragmentant celle-ci. De plus, j’ai pu davantage cibler la région qui contient l’information de sa localisation ainsi que son effet de fragmentation, soit seulement les 23 premiers acides aminés de sa séquence. J’ai également observé que cette région Nterminale (a.a.23) est encore plus efficace pour induire la fragmentation des mitochondries. J’ai pu démontrer que le motif protéique L-Y-R est essentiel pour l’activité de fragmentation. J’ai également validé l’interaction in vivo de AltMID51 avec sa protéine partenaire ACPM (Acyl carrier protein) dans des foci mitochondriaux. En conclusion, mes travaux à la maîtrise ont permis de mettre en évidence que la protéine AltMiD51 est un nouveau facteur impliqué dans la fission mitochondriale. Ces résultats ouvrent de nouvelles perspectives en ce qui concerne la caractérisation de nouvelles protéines alternatives et par leur contribution dans la biologie moléculaire de la cellule. / Abstract : Challenging the dogma that eukaryotic mRNAs contain a single coding sequence, an ever-growing number of studies highlight the possibility for these mRNAs to have several coding sequences, and thereby code for multiple proteins. Thus, eukaryotic mRNAs are multicoding and present alternative open reading frames (AltORFs). These alternative ORFs are present in the non-translated region (UTRs), and within or overlapping the RefORF (reference open reading frame) in non-canonical frames (+2 and +3). The proteome is indeed more complex than we initially thought. However, the role and biological function of these proteins remain to be elucidated. Over the course of my MPhil, I started characterizing the alternative protein AltMiD51, encoded in the 5’UTR of the bicistronic MIEF1/SMCR7L/MID51 gene, and coexpressed with its reference protein (MiD51). Using a wide range of molecular biology, cellular and biochemistry assays, I first demonstrated AltMiD mitochondrial localisation. I then proved AltMiD51 expression alters mitochondrial dynamics, enhancing a fragmented morphology. Moreover, I further characterized the sequence region responsible for AltMiD51 localisation and mitochondrial fragmentation, namely the first 23 amino acids. I also observed that this N-terminal region alone presents a stronger phenotype of mitochondrial fragmentation. In addition, I proved the L-Y-R domain is essential for AltMiD51 fragmentation activity, and I validated AltMiD51 in vivo interaction with ACPM (Acyl Carrier Mitochondrial Protein) within mitochondrial foci. Eventually, the work presented here highlighted AltMiD51 as a novel factor involved in mitochondrial fragmentation. These results shed light on new perspectives regarding the characterisation of alternative proteins and their contribution to the cellular metabolism.

La relativité générale (RG) et le modèle standard des particules permettent de comprendre les quatre interactions fondamentales de la nature. La formulation d'une théorie quantique de la gravitation permettrait d'unifier ces deux tenants de la physique moderne. D'après les grandes théories d'unification, une telle union est possible moyennant la brisure de certaines symétries fondamentales apparaissant à la fois en RG et dans le modèle standard telle la symétrie de Lorentz. Les violations de la symétrie de Lorentz peuvent être paramétrées dans tous les domaines de la Physique par une théorie effective du champ appelée extension du modèle standard (SME). Une violation au principe d'invariance locale de Lorentz dans le secteur gravitationnel serait supposée engendrer des perturbations dans la dynamique orbitale des corps présents dans le système solaire, notamment la Lune. Ainsi, à partir des données extrêmement précises de télémétrie laser, l'orbite lunaire peut être minutieusement analysée afin de débusquer d'éventuelles anomalies dans son mouvement. Dans cette optique, ELPN (Ephéméride Lunaire Parisienne Numérique), une nouvelle éphéméride lunaire intégrée dans le cadre du formalisme SME a été développée durant la thèse. ELPN fournit les solutions au problème lunaire sous la forme de séries temporelles datées en temps dynamique barycentrique (TDB). Parmi les solutions numériquement intégrées, mentionnons la position et la vitesse du vecteur barycentrique Terre-Lune, les angles de librations lunaires, la différence entre le temps terrestre et le TDB, ainsi que l'ensemble des dérivées partielles intégrées depuis l'équation aux variations. Les prédictions de l'éphéméride ont été utilisées afin de réduire les observations lunar laser ranging (LLR). Dans le cadre de la RG, la dispersion des résidus s'est avérée en accord avec les dispersions calculées à partir des éphémérides INPOP13b et DE430. Dans le cadre du SME minimal, l'analyse des données LLR a permis de contraindre toutes violations à l'invariance locale de Lorentz. Une grande attention a été portée à l'analyse des incertitudes afin de fournir des contraintes réalistes. Ainsi, dans un premier temps, les combinaisons linéaires de coefficients SME ont été isolées puis ajustées aux observations. Puis, dans un second temps, les incertitudes réalistes ont été déterminées par une méthode de ré-échantillonnage. L'analyse des données de télémétrie laser Lune n'a pas permis de révéler de violations au principe d'invariance locale de Lorentz agissant au niveau de l'orbite lunaire. Les prédictions de la RG ont donc été validées avec des précisions absolues allant de 10-9 à 10-12. / General Relativity (GR) and the standard model of particle physics provide a comprehensive description of the four interactions of nature. A quantum gravity theory is expected to merge these two pillars of modern physics. From unification theories, such a combination would lead to a breaking of fundamental symmetry appearing in both GR and the standard model of particle physics as the Lorentz symmetry. Lorentz symmetry violations in all fields of physics can be parametrized by an effective field theory framework called the standard-model extension (SME). Local Lorentz Invariance violations in the gravitational sector should impact the orbital motion of bodies inside the solar system, such as the Moon. Thus, the accurate lunar laser ranging (LLR) data can be analyzed in order to study precisely the lunar motion to look for irregularities. For this purpose, ELPN (Ephéméride Lunaire Parisienne Numérique), a new lunar ephemeris has been integrated in the SME framework. This new numerical solution of the lunar motion provides time series dated in temps dynamique barycentrique (TDB). Among that series, we mention the barycentric position and velocity of the Earth-Moon vector, the lunar libration angles, the time scale difference between the terrestrial time and TDB and partial derivatives integrated from variational equations. ELPN predictions have been used to analyzed LLR observations. In the GR framework, the residuals standard deviations has turned out to be the same order of magnitude compare to those of INPOP13b and DE430 ephemerides. In the framework of the minimal SME, LLR data analysis provided constraints on local Lorentz invariance violations. Spetial attention was paid to analyze uncertainties to provide the most realistic constraints. Therefore, in a first place, linear combinations of SME coefficients have been derived and fitted to LLR observations. In a second time, realistic uncertainties have been determined with a resampling method. LLR data analysis did not reveal local Lorentz invariance violations arising on the lunar orbit. Therefore, GR predictions are recovered with absolute precisions of the order of 10-9 to 10-12.