Syftet med studien är att beskriva och analysera lärares och elevers användande av laborativt material i skolår 4-6 när de arbetar med tal i bråkform i matematikundervisningen. Centrala frågor i studien handlar om på vilka sätt det laborativa materialet används i bråkundervisningen, vilka typer av laborativt material används i bråkkundervisningen, vilka dimensioner av variation öppnas upp om tal i bråkform när laborativt material används samt vad som görs möjligt för eleverna att erfara om tal i bråkform. För att studera lärares och elevers användning av laborativt material när de arbetar med tal i bråkform har data samlats in genom deltagande observation i form av videoinspelningar från 20 stycken olika matematikklassrum i skolår 4-6. Datamaterialet har analyserats i två faser. I den första fasen har en tematisk analys gjorts och i den andra fasen har datamaterialet analyserats med hjälp av variationsteorin. Av resultat framgår att lärares och elevers användande av laborativt materialet kan beskrivas utifrån antingen ett konkretiserande arbetssätt eller ett laborerande arbetssätt. Material som används är både vardagligt- eller pedagogiskt material med tonvikt på det vardagliga materialet. När lärare och elever använder det laborativa materialet i matematikundervisningen öppnas det upp för olika dimensioner av variation i relation till undervisningssekvensens lärandeobjekt. De variationsmönster som förekommer i studien är kontrast och generalisering. När en dimension av variation öppnas upp ges eleverna möjlighet att erfara lärandeobjektet.

L'objectif est de produire un antioxydant puissant, l'acide 3,4-dihydroxyphénylacétique (3,4-DHPA) à partir de la L-tyrosine chez l'archée hyperthermophile et acidophile, Sulfolobus solfataricus 98/2. Les microorganismes extrêmophiles possèdent des enzymes particulièrement résistantes et intéressantes pour l'industrie.Des cultures ont donc été réalisées en fermenteur contrôlé dans 4 conditions : (i) en présence de glucose avec ou sans L-tyrosine, (ii) en présence de phénol avec ou sans L-tyrosine. Il a été montré que le 3,4-DHPA est synthétisé seulement en présence de phénol et de L-tyrosine. Les gènes codant pour les enzymes impliquées dans cette voie métabolique et potentiellement responsables de la synthèse du 3,4-DHPA ont été identifiés par homologie de séquence chez cette archée.Des études transcriptomiques et protéomiques ont donc été initiées pour confirmer ces hypothèses et tenter de caractériser les enzymes impliquées dans ces voies métaboliques. Plusieurs toluène-4-monooxygénases (T4MO) et une catéchol 2,3-dioxygénase, impliquées dans le métabolisme du phénol et potentiellement dans la voie de dégradation de la L-tyrosine ont été identifiées. Leur production est soumise à une régulation transcriptionnelle dépendant de la présence de phénol. L'analyse des régions génomiques correspondantes a permis de mettre en évidence une région consensus qui pourrait être impliquée dans la fixation d'un facteur de transcription lors de la régulation par le phénol. Ces différentes études ont permis, de déterminer d'une part dans quelles conditions le 3,4-DHPA est synthétisé, d'autre part d'identifier les enzymes qui interviendraient dans le métabolisme de la L–tyrosine. / The aim is to produce a powerful antioxidant, 3,4-dihydroxyphenylacetic acid (3,4-DHPA) from L-tyrosine in the hyperthermophilic and acidophilus archaea, Sulfolobus solfataricus 98/2. Extremophiles microorganisms have resistant enzymes and interesting for industry. Cultures have been carried out in controlled bioreactor four conditions: (i) in the presence of glucose with or without L-tyrosine, (ii) in the presence of phenol with or without L-tyrosine. It has been shown that 3,4-DHPA is synthesized only in the presence of phenol and L-tyrosine. The genes encoding enzymes involved in the metabolic and potentially responsible for the synthesis of 3,4-DHPA pathway have been identified by sequence homology in S. solfataricus.Des transcriptomic and proteomic studies have therefore been initiated to confirm these hypothesis and attempt to characterize the enzymes involved in these pathways. Several toluene-4-monooxygenase (T4MO) and catechol 2,3-dioxygenase involved in the metabolism of phenol and potentially in the degradation pathway of L-tyrosine were identified. Their production is subjected to a dependent transcriptional regulation of the presence of phenol. The analysis of the corresponding genomic regions has highlighted a consensus region that could be involved in the binding of a transcription factor in the regulation of phenol. These studies helped to determine the one hand the conditions under which 3,4-DHPA is synthesized, secondly to identify enzymes that intervene in the metabolism of L-tyrosine.

Les lymphomes B primitifs du médiastin (LBPMs) constituent une entité anatomo-clinique particulière au sein des lymphomes diffus à grandes cellules B. Les analyses du transcriptome des LBPMs ont montré une forte expression des gènes induits par l’IL-4 ou l’IL-13 et des effecteurs de cette voie de signalisation. L’objectif de ce travail a été d’étudier la voie IL-4/IL-13 dans les LBPMs. Dans une 1ere partie, nous avons montré que le facteur de signalisation et de transcription 6 (STAT6) est constitutivement phosphorylé et possède une activité de liaison à l’ADN dans les lignées dérivées de LBPM (MedB1, Karpas1106). Le STAT6 phosphorylé (-P) est présent dans les noyaux des cellules tumorales de LBPMs (73% des cas). Cette activation est due en partie à l’activité de la kinase JAK2 et aux altérations du gène régulant négativement cette voie de signalisation, SOCS1. Dans une 2eme partie, nous avons étudié le rôle de STAT6 dans la physiopathologie de ces lymphomes en inhibant son expression par un siRNA dans les lignées. Nous avons montré une diminution de la prolifération et une augmentation de la mort cellulaire, ainsi qu’une diminution du taux du mRNA Bcl-xL dans les cellules MedB1. Nous avons observé une corrélation entre l’accumulation nucléaire de STAT6-P et l’expression cytoplasmique de Bcl-xL dans les cellules tumorales. Enfin, nous avons mis récemment en évidence des mutations du domaine de liaison à l’ADN de STAT6, dans 35% des LBPMs. L’étude des mécanismes oncogéniques activés dans la voie IL-4/IL-13 devrait permettre de comprendre le dysfonctionnement cellulaire à l’origine des LBPMs et pourrait aussi donner de nouvelles cibles pour le diagnostic et la thérapie / Primary mediastinal large B-cell lymphomas (PMBCLs) are a particular anatomo-clinical entity among diffuse large B-cell lymphomas (DLBCLs). The transcriptome analyses of PMBCLs showed high expression of genes activated by IL-4 or IL-13 and effectors of this signaling pathway. The objective of this work was study the IL-4 / IL-13 signaling pathway in PMBCLs. In a 1st part, we demonstrated that signal transducer and activator of transcription 6 (STAT6) is constitutively phosphorylated and exhibits DNA binding activity in PMBCL derived cell lines (MedB1, Karpas1106). This phosphorylated STAT6 (P-) is present in nuclei of PMBCL neoplastic cells (73 % of cases). This activation is partially due to the activity of JAK2 kinase and to the alteration of a gene which regulates negatively this signalling pathway, SOCS1. In a 2nd part, we studied the STAT6 role in physiopathology of these lymphomas by inhibiting its expression with a siRNA in cell lines. We showed proliferation decrease and cell death increase, as well as diminution of Bcl-xL mRNA in MedB1 cells. We observed a correlation between P-STAT6 nuclear accumulation and Bcl-xL cytoplasmic expression in neoplastic cells. In a last part, we recently demonstrate mutations of STAT6 DNA binding domain, in 35 % of PMBCLs. The study of oncogenic mechanisms activated in IL-4/IL-13 signaling pathway could allow to understand the cellular dysfunction at the origin of the PMBCLs and could also identify new targets for the diagnostic and the therapy

No description available.

Ce travail de thèse se compose en deux parties :Partie 1Nous nous intéressons à la propagation lumineuse non-linéaire dans des cellules planaires de cristal liquide nématique mélangé avec un colorant, l’effet non-linéaire considéré étant l'effet thermique. Puis, nous nous intéressons à l'amélioration de la fluorescence émise par le colorant.Nous concluons que pour améliorer le spectre de la fluorescence, il faut utiliser une source se propageant en mode soliton, optimiser la distance entre la fibre optique d’excitation de celle de collecte et l’ajout des nanoparticules d'or au cristal liquide. Cette amélioration de la fluorescence ouvrira la voie à la création du laser à colorant assisté par propagation de soliton.Partie 2Nous étudions la dynamique spatiotemporelle d'une cavité en anneau remplie d'un milieu de type Kerr non-instantané et pompée par un faisceau cohérent. Nous effectuons d’abord une étude analytique afin de déterminer les types d’instabilités possibles et leurs seuils. Puis, une étude numérique est menée pour observer l’évolution du champ dans la cavité. Nous montrons l’existence des structures périodiques et localisées. / The work of this thesis consists of two parts:Part 1We are interested in non-linear light propagation in planar cells of nematic liquid crystal mixed with a dye. The non-linear effect is considered to be a thermal effect. Then, we are interested in improving the fluorescence emitted by the dye.We conclude that to improve the fluorescence spectrum, we need to use a source propagating in soliton mode, to optimize the distance between the excitation optical fiber and the collecting one and to add the gold nanoparticles to the liquid crystal. This improvement of fluorescence spectrum will pave the way for the creation of a dye laser assisted with soliton propagation.Part 2We study the spatiotemporal dynamics of a ring cavity filled with a non-instantaneous Kerr-type medium and pumped by a coherent beam. We first carried out an analytical study to determine the types of instabilities and their thresholds. Then, a numerical study is carried out to observe the evolution of the field in the cavity. We show the existence of periodic and localized structures.

No description available.

A identificação de genes relacionados com resistência a compostos antiparasitários tem contribuído para um melhor entendimento do mecanismo de ação de compostos antileishmania. Pouco se sabe sobre o mecanismo de ação do análogo de purina tubercidina (TUB) em Leishmania. Utilizando a estratégia de superexpressão após transfecção gênica, isolamos um locus de Leishmania (Leishmania) major, de 31 kb, capaz de conferir níveis de resistência quatro vezes maior que o parasita selvagem. Várias deleções desse locus foram geradas e a construção de 3 kb (pSNBR/3kbClaI-EcoRI) também conferiu níveis de resistência quando comparado ao parasita elvagem. Através de análises no genoma de L. (L.) major, localizamos esse locus no cromossomo 31 e, no fragmento de 3 kb, um gene que codifica para uma proteína com função desconhecida até o momento (LmjF.31.2010). Esta proteína foi relacionada com resistência a TUB em todas as linhagens transfectadas analisadas (cosTUB2 e pSNBR/3kbClaI-EcoRI), assim denominamos LmjF.31.2010, de proteína relacionada com resistência a TUB (PRRT). A quantificação relativa de transcritos de mRNA na construção pSNBR/3kbClaI-EcoRI apresentou níveis altos de transcritos da PRRT. Foram gerados ainda mutantes de L. (L.) major e L. (L.) amazonensis resistentes a TUB e estes se apresentaram bem adaptados a concentrações altas de TUB, apresentando razão de resistência maior que 200 vezes, quando comparado com os respectivos parasitas selvagens. A PRRT também foi relacionada na resistência a TUB nos mutantes gerados, pois houve amplificação gênica de prrt. Os resultados obtidos neste trabalho fornecem dados para inferir a importância da PRRT no mecanismo relacionado com resistência a TUB. / The identification of genes associated with resistance to antiparasitic compounds has contributed to a better understanding of the mechanism of action of compounds against Leishmania. Little is known about the mechanism of action of purine analog tubercidin (TUB) in Leishmania. Using a strategy of gene overexpression after transfection, we isolated a locus of Leishmania (Leishmania) major, 31 kb, capable of conferring fold resistance four times greater than the wild type parasite. A set of deletions of this locus were generated and a 3 kb construction (pSNBR/3kbClaI-EcoRI) conferred fold resistance twice than the wild type. Analysis of L. (L.) major genome, located this locus on chromosome 31 and on 3 kb fragment we identified a gene encoding a protein with unknown function (LmjF.31.2010). This protein has been related to TUB resistance in all strains analyzed (cosTUB2 and pSNBR/3kbClaI-EcoRI), so we named mjF.31.2010 of protein related with resistance to TUB (PRRT). Relative quantification of mRNA transcripts in the construction pSNBR/3kbClaI-EcoRI showed high levels of PRRT transcripts.Mutants of L. (L.) major and L. (L.) amazonensis resistant to TUB were also generated and these were well adapted to high TUB concentrations, presenting fol resistance greater than 200 times when compared with their respective wild type. The PRRT was also related to TUB resistance mutants generated by PRRT gene amplification. Despite the high fold resistance presented by TUB resistant mutants, the ratio of expression of these mutant PRRT transfected and wild was similar to the wild type.

Lipopolissacarídeos (LPS), pode tanto proteger quanto exacerbar o desenvolvimento da asma. LPS inicia a ativação da resposta imune via ligação da molécula Toll-like receptor 4 (TLR4) que sinaliza por duas vias distintas, as moléculas adaptadoras MyD88 e TRIF. LPS é um adjuvante que induz resposta do tipo Th1, enquanto que o hidróxido de alumínio (Alum) desperta respostas Th2, porém, a mistura de ambos adjuvantes na indução da resposta alérgica pulmonar ainda não foi investigada. No presente estudo, nós determinamos o efeito de dois agonistas de TLR4, um natural (LPS) e outro sintético (ER-803022) adsorvidos ao Alum sobre o desenvolvimento de doença alérgica pulmonar. Os animais foram sensibilizados pela via subcutânea com os antígenos, Ovoalbumina (OVA) ou Toxóide Tetânico (TT) na presença ou ausência de agonistas de TLR4 co-adsorvidos ao Alum e desafiados com os respectivos antígenos pela via intranasal. Nossos resultados mostraram que a sensibilização com OVA ou TT e LPS coadsorvidos ao Alum, impede o estabelecimento da resposta alérgica mediada por linfócitos Th2, tais como, influxo de eosinófilos, produção de citocinas do tipo 2, hiperreatividade brônquica, secreção de muco, e produção de IgE ou IgG1 anafilática. Apesar dos níveis de IgG2a, isotipo associado com as respostas Th1 estarem aumentados, análise da histopatologia pulmonar não revelou um desvio para o padrão Th1 de inflamação. Verificamos que a presença das moléculas TLR4, MyD88, IL-12/IFN-g mas não TRIF foram necessários para LPS exercer seu efeito inibitório. O agonista sintético de TLR4, menos tóxico que LPS, também protegeu contra o desenvolvimento de inflamação alérgica pulmonar. Em conclusão, nosso trabalho esclarece o efeito da sinalização do TLR4 na sensibilização alérgica e indica que agonista sintético de TLR4 com baixa toxicidade, pode ser utilizado para modular a capacidade adjuvante do Alum e conseqüentemente diminuir a indução de alergias. / Epidemiological and experimental data suggest that bacterial lipopolysaccharides (LPS) can either protect from or exacerbate allergic asthma. LPS triggers immune responses through Toll-like receptor (TLR) 4 that in turn activates two major signaling pathways via either MyD88 or TRIF adaptor proteins. LPS is a pro-Th1 adjuvant while aluminum hydroxide (Alum) is a strong Th2 adjuvant, but the effect of mixing both adjuvants on development of lung allergy has not been investigated. We determined whether natural (LPS) or synthetic (ER-803022) TLR4 agonists adsorbed onto alum adjuvant affect allergen sensitization and development of airway allergic disease. To dissect LPS-induced molecular pathways we used TLR4, MyD88, TRIF, or IL-12/IFN-g deficient mice. Mice were sensitized subcutaneously to allergens such as ovalbumin (OVA) or tetanus toxoid (TT) with or without TLR4 agonists coadsorbed onto Alum and challenged twice via intranasal route with the same allergens. The development of type 2 immunity was evaluated 24 h after last allergen challenge. We found that sensitization with OVA or TT plus LPS co-adsorbed onto Alum impaired allergeninduced Th2-mediated responses such as airway eosinophilia, type 2 cytokines secretion, airway hyperreactivity, mucus hyper production and serum levels of IgE or IgG1 anaphylactic antibodies. Although the levels of IgG2a, a Th1 affiliated isotype increased, investigation into the lung-specific effects revealed that LPS did not induce a Th1 pattern of inflammation. LPS impaired the development of Th2 immunity, signaling via TLR4 and MyD88 molecules via the IL-12/IFN-g axis, but not through TRIF pathway. Moreover, the synthetic TLR4 agonists that proved to have a less systemic inflammatory response than LPS also protected against allergic asthma development. TLR4 agonists co-adsorbed with allergen onto Alum down modulate Th2 immunity and prevent the development of polarized T cell-mediated airway inflammation. Thus, our work clarifies the effect of TLR4 signaling in allergic sensitization and indicates that TLR4 agonists with low toxicity might be useful for down regulating the pro-Th2 adjuvant activity of alum and consequently decrease the induction of allergy.

A análise de demonstrações contábeis é utilizada em processos decisórios e diversos de seus usuários são externos às empresas estudadas, com os interesses variando de acordo com o relacionamento que cada um deles tem ou pretenda ter com a empresa analisada. Conforme o interesse específico do usuário da análise, pode haver maior valorização de algumas informações e técnicas em detrimento de outras. Para executar seus estudos, os usuários defrontam-se com dois limitadores, quais sejam as informações disponibilizadas pelas empresas e as técnicas de análise. Cabe ao analista e principalmente ao usuário que contrata seus serviços definir que técnicas utilizar em seu processo decisório. As técnicas não são mutuamente excludentes e muitas vezes acabam por ter uma atuação complementar ou confirmatória de diagnósticos alcançados por outras técnicas. Mesmo entre usuários com interesses análogos costumam existir diferenças nas técnicas selecionadas para composição do processo de análise, pois a seleção reflete crenças, costumes e preferências dos executores do trabalho de análise e dos que decidem. Em relação às técnicas de análise de domínio público é importante destacar que: enfatizam principalmente a análise individual das demonstrações; investigam a composição individual das demonstrações e a evolução de suas contas e indicadores através do tempo; estão voltadas principalmente para o curto prazo; seu produto final, normalmente, é um diagnóstico elaborado sobre uma base retrospectiva de dados. Este trabalho tem como principal objetivo propor mais uma técnica de análise, a análise referencial, cujos diferenciais são a análise conjunta de demonstrações contábeis e o foco no longo prazo. A análise referencial parte do pressuposto de que o ativo total mais recente é a melhor base para comparação de contas de quaisquer demonstrações, presentes ou passadas. A análise referencial mostra as diversas contas a elas submetidas em número de pontos do último ativo total conhecido e esta característica facilita tanto alongar o horizonte temporal como incluir demonstrações contábeis conceitualmente diferentes. A análise referencial é, pois, uma técnica de análise que integra as demonstrações contábeis. Pode tanto ser utilizada para obter resultados próprios, como para servir de base a pesquisas de maior profundidade. Neste trabalho foram realizados dois ensaios para comprovar esta qualidade. No primeiro, a análise referencial serviu como auxiliar para apontar as mais eficientes companhias abertas do setor de papel e celulose entre os anos de 1996 e 2002. No segundo, o uso da análise referencial foi estendido a variáveis não relacionadas a demonstrações contábeis e, através dela, ficou facilitada a averiguação acerca de eventuais correlações entre variáveis contábeis selecionadas e preços de ações das principais companhias abertas entre 1996 e 2002. Todavia era preciso ainda atestar sua validade e utilidade junto a usuários, visto que a análise de demonstrações contábeis existe para atendê-los. Foi feita uma pesquisa de campo com 50 usuários das áreas de crédito, investimento e regulação de mercado e, de modo geral, houve concordância quanto à análise referencial ser um instrumento válido e útil. Este resultado deve ser considerado como um indício favorável, pois há ciência de que a técnica só pode ser definitivamente validada como de domínio público se houver divulgação e efetiva utilização pela comunidade acadêmica e principalmente pelos usuários de análise de demonstrações contábeis. Foi também realizada uma pesquisa experimental com dois grupos de alunos de pós-graduação para verificar se há mais agilidade com o uso da análise referencial e se ela facilita a comprovação dos resultados. Concluiu-se que não existe ganho de tempo no processamento nas informações, mas há maior segurança por parte do usuário quanto aos resultados dos estudos em utilizando a análise referencial. / Balance sheet analysis is used for several kinds of decision making. Many are the external users of balance sheet analysis and anyone has its own interests that vary according to the relationship with the entities studied by balance sheet analysis. Depending on the user’s particular interest some concepts and tools are considered more important than others. To do his job the analysts have two limits that are the information made available by the companies and the analysis technical tools. The decision on what kind of tools to be used in the decision process is a problem to be solved by the analyst and mainly by the user that hire his services. Such tools are not mutually exclusive and several times other tools can be used to complete or to confirm the obtained diagnostics. Often times users with similar purposes do not select the same tools for their decision process analyses because the selection of such tools reflects the individual beliefs, habits and preferences of the analyst or the users of balance sheet analysis. With reference to commonly used balance sheet analysis it is important to remind that they emphasize the analysis of singular balance sheets and are intended to explain the individual composition of each balance sheet as well as to shows the evolution of accounts and indicators in the short term and therefore they make conclusive studies based upon a database of past information. This academic work intends mainly to introduce a new tool of analysis named reference analysis which is intended to make analysis with sets of balance sheets and focused on long term analysis. The assumption made by the reference analysis is that the most recent value of total assets is the best base to make accounts comparisons of any balance sheet, either present or past. This characteristic of the reference analysis allows the analyst to turn each account of any balance sheet into a number of points in relation to the last total assets and therefore making the long term analysis work easier as well as making possible to do analysis with balance sheets of different companies. The reference analysis allows integrated analysis and can be used either to get results by itself or to offer facilities basis for other deeper studies. In this work there were made two empirical studies to show some possibilities. In the first one the reference analysis was used as an auxiliary to point out the most efficient Brazilian pulp and paper companies from 1996 to 2002. In the other study, the reference analysis was extended to variables not related to balance sheets with the purpose of verifying correlation between stock prices of the main Brazilian companies and some selected accounting information from 1996 to 2002. Nevertheless, it was still necessary to certify the validity and utility of the tool among the users considering that balance sheet analysis is believed to exist in favor of such users. It was run a field research with 50 users in the credit, investment and market regulation areas, and it was found that reference analysis was considered in general as a useful and valid tool. This result must be considered as a favorable indication because it is accepted that a technique can only be definitively validated if it presents an effective use by the academic community and mainly by the users of balance sheet analysis. It was also carried out an experimental research with two groups of postgraduates to verify if the use of the reference analysis makes the analysis faster and if it facilitates the evidence of the results. It was concluded that there are not gains of time in the information processing however the confidence of the users as to the results obtained by using the reference analysis was found greater.

Ces dernières décennies ont vu une évolution remarquable du contexte économique des entreprises. Ceci est dû certainement à la compétition fortement croissante à laquelle elles sont confrontées. Cette forte concurrence a entraîné les entreprises à investiguer des voies pour améliorer leurs performances économiques tout en répondant aux mieux aux exigences de leurs clients. La clé de la réussite de la majorité des entreprises réside dans la mise en place d’une méthode de gestion économique des différentes fonctions. Les industriels et les chercheurs ont prouvé l’existence d’une forte interaction entre trois fonctions fondamentales de l’entreprise ; la maintenance, la production et la qualité. Ils ont démontrés qu’une gestion indépendante de ces trois fonctions n’est plus efficiente. Suite à ce constat, nous nous sommes intéressés dans ce projet de recherche au développement de nouvelles stratégies de maintenance intégrée à la production et à la qualité. En tenant compte du prix de vente, des coûts de retouche, de la maintenance et ceux de la production, une analyse de l’interdépendance des trois fonctions a permis de réaliser notre objectif qui consiste à maximiser les profits des entreprises. Le but de cette thèse consiste, à proposer des nouvelles approches de maintenance intégrée à la qualité en tenant compte de la dégradation progressive du système de production, son impact sur la qualité des produits finis et l’impact économique des actions de retouche. Des modèles analytiques ont été développés afin d’illustrer les stratégies proposées. L’effet de la dégradation du système de production sur la perte de qualité du produit fini et son impact économique ont été mis en équation par le biais de modèles mathématiques. Dans ce contexte, différentes politiques de maintenance (parfaite, imparfaite, semi parfaite) ont été traitées. L’existence des solutions optimales liées aux variables de décision a été démontrée analytiquement. Enfin, des résolutions numériques, basées sur des cas industriels, ont été présentées afin de valider les résultats théoriques obtenus. La robustesse des modèles analytiques développés a été prouvée par des études de sensibilité / The last few decades have been marked by a remarkable change in the economic environment of companies. It is due certainly to the increasing competition that they face. This strong competition has led companies to investigate new ways to improve their economic performance while meeting their customers' requirements. The key to the success of the majority of companies lies in the implementation of an economic management method of various functions. Industry and researchers have demonstrated a strong interaction between the three fundamental functions of the company; maintenance, production and quality. They have demonstrated that an independent management of these three functions is no more efficient. Following this observation, we were interested in this research project in the development of new maintenance strategies integrated production and quality. Taking into account sales prices, reworking costs, maintenance costs and production costs, an analysis of the interdependence of the three functions enabled us to achieve our goal of maximizing the profits of companies. The purpose of this thesis is to propose new approaches integrated quality and maintenance taking into account the progressive degradation of the production system, its impact on the quality of output products and the economic impact of reworking actions. Analytical models have been developed to illustrate the proposed strategies. The effect of the degradation of the production system on the degradation of quality of output products and its economic impact has been modeled using mathematical models. In this context, various maintenance policies (perfect, imperfect, semi-perfect) have been studied. The existence of optimal solutions related to the decision variables has been analytically demonstrated. Finally, numerical resolutions, based on industrial cases, have been presented in order to illustrate the theoretical results obtained. The robustness of the analytical models developed has been proved by sensitivity studies