Dans un contexte où l'importance de la Responsabilité Sociale des Entreprises (RSE) va croissante, cette thèse explore la relation entre la RSE et plusieurs attributs financiers des entreprises comme l'information spécifique incorporée dans le prix des actions, le risque de détresse financière des entreprises et le niveau de crédit commercial. Les chercheurs en finance d'entreprise présentent deux points de vue opposés sur la RSE: "Faire le bien est bon pour les affaires" et "La RSE crée des problèmes d'agence". Le premier chapitre aborde brièvement les théories analysant les répercussions financière de la RSE et met en évidence les avantages financiers concomitants aux pratiques responsables. Les entreprises socialement responsables améliorent l'environnement informationnel ce qui complète l'information financière. Dans le deuxième chapitre, nous montrons que la RSE joue un rôle important dans l'amélioration de l'information incorporée dans les cours boursiers. Une meilleure performance RSE est appréciée par les investisseurs et les gestionnaires d'actifs et améliore la disponibilité des financements. Le troisième chapitre explique que les entreprises peuvent atténuer leur risque de détresse financière (Z-score) en améliorant leur performance en matière de RSE. Des entreprises plus responsables promeuvent de meilleures relations avec les parties prenantes grâce à un objectif de confiance et de maximisation de la valeur. Dans le quatrième chapitre, nous constatons que les entreprises socialement responsables ont un meilleur accès au financement (côté fournisseur du crédit commercial) et font plus confiance à leurs clients (côté acheteur du crédit commercial). Par conséquent, cette dissertation fournit un ensemble de résultats soulignant la pertinence et l'importance de "Faire le bien est bon pour les affaires". / In the context of the rapidly growing importance of Corporate Social Responsibility (CSR), this dissertation explores the relationship between CSR and firm financial attributes, like stock price informativeness, financial distress risk, and trade credit. First chapter briefly discusses the theories of CSR and highlights the financial advantages of favorable CSR practices. Corporate finance researchers present two opposite views on CSR, “Doing good is good for business” and “CSR creates agency problems”. In the second chapter, we testify this association and find that CSR plays an important role to improve the information impounding in stock prices. Socially responsible firms improve the financial information environment. Third chapter elaborates that firms can mitigate their financial distress risk (Z-score) through improved CSR performance. Firm better CSR performance is appreciated by the investors and asset managers and it improves the availability of finance. In fourth chapter, we find that socially responsible firms have better access to finance (supplier side of trade credit) and have more trust on their stakeholders (buyer side of trade credit). Better CSR firms promote the better relationship with stakeholders through trust and value maximization goal. Therefore, this dissertation provides evidence on the importance of “Doing good is good for business”.

Neste trabalho estudamos uma nova classe de materiais ópticos não-lineares, os cristais orgânicos, que possuem potencial para muitas aplicação em dispositivos. Determinamos diferentes propriedades ópticas lineares e não-lineares de três cristais orgânicos: a l-alanina, a l-treonina e a l-lisina. Esses cristais de aminoácido foram escolhidos por apresentarem propriedades de geração de segundo harmônico (GSH) e por serem materiais nunca estudados sob o ponto de vista da óptica não-linear. Estudamos algumas das propriedades ópticas lineares fundamentais desses cristais biaxiais transparentes, pois deles dependem os fenômenos não-lineares sobre os quais são feitas intensas pesquisas. Determinamos as propriedades lineares como os espectros de absorção, os índices de refração, os eixo ópticos, velocidade de propagação da luz num meio anisotrópico e os limiares de dano por radiação. Posteriormente, determinamos as condições de casamento de fase, a eficiência de GSH, e a auto-modulação de fase. A GSH e a auto-modulação de fase pertencem, respectivamente, a processos não-lineares de segunda e de terceira-ordem. Para o estudo de muitas dessas propriedades foram desenvolvidas novas técnicas experimentais. Uma dessas novas técnicas, a varredura-Z oscilante, teve sensibilidade para determinar, pela primeira vez, o índice de refração não oscilante, vez, o índice de refração não linear desses cristais orgânicos. Além disso, como a todos os processos de caracterização envolveram a preparação de amostras, tivemos a oportunidade de criar procedimentos padrões para manipulação e utilização desses novos materiais. / In this work we studied a new class of nonlinear organic crystals that are potential candidates for devices application. We determined several linear and nonlinear optical properties of three organic crystals: l-alanine, l-threonine and l-lysine. These aminoacid. These aminoacid because their nonlinearities were never studied before. We characterized some of the fundamental linear optical properties of these biaxial transparent crystals, because they have influence on nonlinear phenomena that attracted a lot of research. We determined linear properties like absorption spectra, indices of refraction, optical axes, the light speed propagation in anisotropy media and the optical damage threshold. Subsequently, we determined the phase-matching condition for SHG, efficiency of the SHG and self-phase modulation. The SHG and self-phase modulation belongs, respectively, to the second-order and third-order nonlinear processes. To study several of these properties we had to develop some new experimental techniques. One of them, the oscillatory Z-scan, allows enough sensibility to determine, for the first time, the nonlinear refraction index of these organic crystals. Besides, as all these optical characterization involve the preparation of the samples, we had the opportunity to establishing standard procedures for manipulation of these new materials.

O crescimento é um processo dinâmico que muda ao longo da vida. O crescimento ósseo é um evento multicausal no qual, além dos fatores biológicos, intervêm outras características como as relacionadas ao nível socioeconômico, à raça, ao período perinatal, aos hábitos, entre outros. Este estudo objetivou identificar fatores associados ao crescimento transversal do osso maxilar representado pela medida da distância intermolar superior. Foi realizado um estudo seccional aninhado numa coorte, com uma amostra de 158 crianças entre 7 e 9 anos de idade das escolas urbanas de Acrelândia, município da Amazônia Ocidental Brasileira. A variável dependente foi a distância intermolar superior, medida entre as fossas centrais dos primeiros molares superiores permanentes. A partir da idade da introdução da mamadeira foi desenvolvida uma escala assumindo valores de 1 a 10. O sexo, o peso ao nascer, o padrão de uso da mamadeira e o escore Z do índice de massa corporal (IMC) para a idade foram consideradas como variáveis independentes, sendo analisadas por meio de modelo de equações estruturais (MEE). Foram encontrados efeitos diretos positivos significativos do sexo (CP=0,203; p=0,007), peso ao nascer (CP=0,155; p=0,046) e escore Z do IMC para a idade (CP=0,165; p=0,030) sobre o crescimento transversal do maxilar. Os efeitos indiretos (CP=0,058; p=0,029) e o efeito total (CP=0,262; p=0,000) do sexo sobre o desfecho mostraram significância estatística. Os efeitos indiretos do peso ao nascer sobre o desfecho não foram significativos (CP=0,018; p=0,508), porém, o efeito total foi significativo (CP=0,174; p=0,023). Em conclusão, o sexo, o peso ao nascer, a idade de introdução da mamadeira e o escore Z do IMC para a idade associam-se ao crescimento transversal do osso maxilar. Além de contribuir para um adequado peso ao nascer da criança, políticas e programas que favoreçam o cuidado pré natal e condições para garantir um parto a termo podem repercutir positivamente no crescimento transversal do maxilar. Do ponto de vista da Vigilância em Saúde, crianças com peso ao nascer diminuído, padrão inadequado de aleitamento materno e déficit nutricional para a idade podem apresentar maior probabilidade de desenvolver atrofia dos maxilares podendo, conforme a gravidade, redundar numa oclusopatia com importante impacto na qualidade de vida / Growth is a dynamic process that changes throughout life. Bone growth is a multicausal event in which other characteristics such as socioeconomic level, race, perinatal period, habits, and others are involved in addition to biological factors. This study aimed to identify with the associated factors transverse growth of the maxillary bone represented by the superior intermolar distance. A cross-sectional survey nested in a population-based cohort study was conducted with a sample of 158 children aged 7 to 9 years old from the urban schools of Acrelandia, a small town in the Brazilian Western Amazon. The dependent variable was the upper intermolar distance measured between the central fossae of the first permanent maxillary molars. From the age of bottle introduction, a scale was developed assuming values from 1 to 10. Sex, birth weight, bottle introduction scale and Z score of body mass index (BMI) for age (BAZ) were considered as independent variables, being analyzed with structural equations model (SEM). Significant direct positive effects of sex (CP=0,203; p=0,007), birth weight (CP=0,155; p=0,046) and BAZ (CP=0,165; p=0,030) on transverse maxillary growth were found. The indirect effects (CP=0,058; p=0,029) and the total effect (CP=0,262; p=0,000) of sex on the outcome were statistically significant. The indirect effects of birth weight on outcome were not significant (CP=0,018; p=0,508), however, the total effect was significant (CP=0,174; p=0,023). In conclusion, sex, birth weight, bottle beginning age and BMI Z score for age showed association with the transverse growth of the maxillary bone. In addition to contributing to an adequate birth weight of the child, policies and programs that favor prenatal care and conditions to guarantee a full-term birth can positively affect transversal growth of the maxilla. From a Health Surveillance point of view, children with reduced birth weight, inadequate breastfeeding pattern and nutritional deficit for age may be more likely to develop atrophy of the jaws which, depending on the severity, may result in malocclusion with an important impact on quality of life

O crescimento é um processo dinâmico que muda ao longo da vida. O crescimento ósseo é um evento multicausal no qual, além dos fatores biológicos, intervêm outras características como as relacionadas ao nível socioeconômico, à raça, ao período perinatal, aos hábitos, entre outros. Este estudo objetivou identificar fatores associados ao crescimento transversal do osso maxilar representado pela medida da distância intermolar superior. Foi realizado um estudo seccional aninhado numa coorte, com uma amostra de 158 crianças entre 7 e 9 anos de idade das escolas urbanas de Acrelândia, município da Amazônia Ocidental Brasileira. A variável dependente foi a distância intermolar superior, medida entre as fossas centrais dos primeiros molares superiores permanentes. A partir da idade da introdução da mamadeira foi desenvolvida uma escala assumindo valores de 1 a 10. O sexo, o peso ao nascer, o padrão de uso da mamadeira e o escore Z do índice de massa corporal (IMC) para a idade foram consideradas como variáveis independentes, sendo analisadas por meio de modelo de equações estruturais (MEE). Foram encontrados efeitos diretos positivos significativos do sexo (CP=0,203; p=0,007), peso ao nascer (CP=0,155; p=0,046) e escore Z do IMC para a idade (CP=0,165; p=0,030) sobre o crescimento transversal do maxilar. Os efeitos indiretos (CP=0,058; p=0,029) e o efeito total (CP=0,262; p=0,000) do sexo sobre o desfecho mostraram significância estatística. Os efeitos indiretos do peso ao nascer sobre o desfecho não foram significativos (CP=0,018; p=0,508), porém, o efeito total foi significativo (CP=0,174; p=0,023). Em conclusão, o sexo, o peso ao nascer, a idade de introdução da mamadeira e o escore Z do IMC para a idade associam-se ao crescimento transversal do osso maxilar. Além de contribuir para um adequado peso ao nascer da criança, políticas e programas que favoreçam o cuidado pré natal e condições para garantir um parto a termo podem repercutir positivamente no crescimento transversal do maxilar. Do ponto de vista da Vigilância em Saúde, crianças com peso ao nascer diminuído, padrão inadequado de aleitamento materno e déficit nutricional para a idade podem apresentar maior probabilidade de desenvolver atrofia dos maxilares podendo, conforme a gravidade, redundar numa oclusopatia com importante impacto na qualidade de vida / Growth is a dynamic process that changes throughout life. Bone growth is a multicausal event in which other characteristics such as socioeconomic level, race, perinatal period, habits, and others are involved in addition to biological factors. This study aimed to identify with the associated factors transverse growth of the maxillary bone represented by the superior intermolar distance. A cross-sectional survey nested in a population-based cohort study was conducted with a sample of 158 children aged 7 to 9 years old from the urban schools of Acrelandia, a small town in the Brazilian Western Amazon. The dependent variable was the upper intermolar distance measured between the central fossae of the first permanent maxillary molars. From the age of bottle introduction, a scale was developed assuming values from 1 to 10. Sex, birth weight, bottle introduction scale and Z score of body mass index (BMI) for age (BAZ) were considered as independent variables, being analyzed with structural equations model (SEM). Significant direct positive effects of sex (CP=0,203; p=0,007), birth weight (CP=0,155; p=0,046) and BAZ (CP=0,165; p=0,030) on transverse maxillary growth were found. The indirect effects (CP=0,058; p=0,029) and the total effect (CP=0,262; p=0,000) of sex on the outcome were statistically significant. The indirect effects of birth weight on outcome were not significant (CP=0,018; p=0,508), however, the total effect was significant (CP=0,174; p=0,023). In conclusion, sex, birth weight, bottle beginning age and BMI Z score for age showed association with the transverse growth of the maxillary bone. In addition to contributing to an adequate birth weight of the child, policies and programs that favor prenatal care and conditions to guarantee a full-term birth can positively affect transversal growth of the maxilla. From a Health Surveillance point of view, children with reduced birth weight, inadequate breastfeeding pattern and nutritional deficit for age may be more likely to develop atrophy of the jaws which, depending on the severity, may result in malocclusion with an important impact on quality of life

Especificações formais são úteis para descrever o que um sistema deve fazer sem definir como, e, em virtude da sua natureza formal e da possibilidade de abstração, é possível analisá-las sistematicamente. No entanto, o uso de especificações formais como parte do desenvolvimento de software não constitui prática comum. Isso se dá, em parte, pelo fato de existirem apenas um pequeno número de metodologias e ferramentas adequadas que dêem suporte a esse desenvolvimento. O primeiro objetivo deste trabalho é propor uma metodologia de desenvolvimento que possibilite, a partir de uma especificação formal em notação Z, produzir uma implementação dessa especificação em Java. Essa metodologia centra-se na geração do esqueleto da aplicação Java e na instrumentação desse esqueleto com mecanismos de verificação de condições (invariantes, pré e pós-condições) e rastreamento de violações dessas condições. Através desses mecanismos, possibilita-se intercalar desenvolvimento formal e informal no processo global de desenvolvimento de software. O segundo objetivo é desenvolver uma ferramenta que implemente parte dessa metodologia, produzindo uma implementação parcial que deverá ser complementada pelo usuário. / Formal specifications are useful for describing what a system should do, without defining how, and, owing to its formal nature, it is possible to analyse them systematically. However useful formal specifications are, their usage as part of the software development process is rather rare. This is, in part, due to the scarcity of both methodologies and tools that support this development. The first goal of this work is to define a software development methodology that enables the developer to produce a Java application from a formal specification written in Z. This methodology will rely strongly on the generation of Java application skeletons and instrumentation of the generated code with means of verifying conditions (invariants, pre and post-conditions) e tracing violations of these conditions. Through this mechanisms, it is possible to mix formal and informal development in the global software development process. The second goal of this work is to develop a tool that will implement part of this methodology, producing a partial implementation that must be complemented by the developer.

A citocinese bacteriana é controlada por diversas proteínas que se agrupam em um complexo chamado divisomo. O cerne do divisomo é constituído por FtsZ, uma proteína homóloga à tubulina eucariótica, que se auto-associa formando uma estrutura chamada anel Z. O anel Z serve como arcabouço e recruta diversas outras proteínas componentes do divisomo para o sítio onde o septo será sintetizado na célula. A formação do anel Z é modulada por proteínas que se ligam diretamente a FtsZ e regulam a sua auto-associação, tanto induzindo como inibindo a sua polimerização. Apesar de muitos destes moduladores de FtsZ já serem conhecidos, muito pouco se sabe sobre o mecanismo pelo qual eles controlam a estruturação do anel Z in vivo. O objetivo do presente trabalho foi estudar a interação entre FtsZ e um modulador de divisão, a proteína ZapA, da bactéria gram-positiva Bacillus subtilis. Para isso construímos uma biblioteca de mutantes de ftsZ por \"Error Prone PCR\", com aproximadamente 1 substituição por cópia de ftsZ e contendo um total de 1x105 clones. A partir dessa biblioteca, utilizamos duas triagens genéticas para identificar mutantes incapazes de interagir com ZapA. Na primeira estratégia, selecionamos 12 mutantes de FtsZ resistentes à superexpressão de uma forma tóxica de ZapA, que bloqueia a divisão, causando filamentação e morte das células. Surpreendentemente, apesar destes mutantes serem insensíveis ao efeito de ZapA, ensaios citológicos mostraram que nenhum deles perdeu a interação com ZapA. Como as mutações foram mapeadas nas vizinhanças do sítio catalítico e de polimerização de FtsZ, e como a maioria delas confere resistência cruzada aos efeitos de outros moduladores de FtsZ, suspeitamos que elas afetassem a estabilidade do polímero de FtsZ e, consequentemente, o comportamento do anel Z. Essas suspeitas foram confirmadas em ensaios de FRAP e cálculos de proporção de FtsZ no anel Z, indicando que os mutantes formam um anel Z mais estável que o normal. Como não obtivemos mutantes que perderam a interação com ZapA na primeira triagem, aplicamos a biblioteca em uma segunda estratégia de triagem genética, procurando um mutante de FtsZ que voltasse a interagir com um mutante de ZapA que não se liga mais a FtsZ (ZapAN62A). Esta estratégia de ganho de função identificou um candidato, FtsZE91V , que, tanto por critérios genéticos como citológicos, voltou a interagir com ZapAN62A. Apesar do mutante FtsZE91V mostrar-se capaz de restaurar a interação com ZapAN62A, ele não afetou a interação com ZapA selvagem, segundo nossos ensaios de microscopia de fluorescência e viabilidade. O mutante FtsZE91V, mapeia na hélice H3 de FtsZ. Esta hélice está exposta na superfície de FtsZ (compõe um dos lados da molécula de FtsZ) de uma maneira compatível com a idéia de que ela seria importante para interações laterais entre polímeros de FtsZ. Nossos resultados apontam, portanto, que a hélice H3 deve ser o sítio de interação para ZapA em FtsZ. / The bacterial cytokinesis is ruled by a number of proteins that constitute the divisome complex. FtsZ, a homologue of eukaryotic tubulin, is the main component of the divisome and self-associates in a structure named Z ring. The Z ring works as a scaffold and recruits the other components of divisome, establishing itself where the septum will be synthesized in the cell. Some of these proteins interact directly with FtsZ and control self-association, promoting polymerization or preventing it. Although there have been discovered many of FtsZ modulators, little is known about the mechanisms that control the formation of the Z ring in vivo. The aim of this work was study de interaction between FtsZ e one of its division modulators, ZapA protein, on Bacillus subtilis grampositive bacteria. We created a mutagenized ftsZ plasmid library by error prone PCR, which contained 1,0x105 transformants and exhibited a mutation rate of one substitution per ftsZ copy. The library was transformed into a modified Bacillus subtilis strain and we performed two genetic screenings to select cells with FtsZ mutants incapable of interacting with ZapA. In first strategy, we selected 12 resistant ftsZ mutants for a toxic ZapA overexpression, that blocked division and caused filamentation and cell death. Surprisingly, although these mutants were insensitive to ZapA effect, cytological assays showed that none of them lost interaction with ZapA. As the substitutions were mapped around the catalytic and interaction site of FtsZ structure and showed resistance to other modulators, we suspected that the mutations were affecting the polymer stability of FtsZ and, consequently, the behavior of Z ring. This hypothesis was confirmed by FRAP experiments and by calculations of FtsZ proportions in Z ring, pointing out that the mutants form more stable Z rings. As we didnt\' find mutants that lost their ZapA´s interaction, we applied our library in a second genetic screen, looking for mutants that return to interact with a ZapA mutant (ZapAN62A) that doesn´t bind to FtsZ anymore. This gain of function strategy identified one candidate, FtsZE91V, which returns to interact with ZapAN62A in our genetic and cytological assays. Although the mutant FtsZE91V showed itself capable to interact with ZapAN62A, that didn´t affect the interaction with wild type ZapA by our fluorescent microscopy and viability assays. The substitution E91V was mapped on H3 helix of FtsZ structure. This helix is exposed on FtsZ surfaces (on FtsZ´s lateral side), being compatible with the idea that lateral interaction is important in FtsZ polymers. So, we concluded that helix H3 is the binding site of ZapA in FtsZ.

Les composés organiques et organométalliques représentent des matériaux prometteurs pour leurs applications dans divers domaines tels que l'optique non linéaire, l'optoélectronique, la photonique et le stockage des données par voie optique. Dans ce travail,nous avons étudié les propriétés optiques non linéaires(ONL) de deux familles de composés à savoir des molécules organiques à base de BODIPY et des complexes organométalliques à base de ruthénium (II)et de fer (II). Pour cette étude nous avons utilisé un laser pulsé en régime picoseconde qui délivre deux longueurs d'ondes : 1064 nm et 532 nm. Nous avons utilisé 1064nm pour les techniques de la génération de la seconde harmonique (SHG) et la génération de la troisième harmonique (THG) et 532 nm pour celle de Zscan.Les résultats obtenus sont intéressants et originaux et montrent bien que la réponse non linéaire dépend du nombre de groupements donneurs d’électrons pour les molécules organiques à base de BODIPY. Le même comportement a été observé dans le cas des complexes organométalliques à base de ruthénium (II) et de fer (II) mettant en évidence la modulation de la réponse optique non linéaire en fonction de la nature du métal de transition utilisé(Ru(II)ou Fe(II)) et de la nature des ligands auxiliaires autour du fragment organométallique (Ru(II)). / Organic and organometallic compounds represent an important potential in many fields such as optics, optoelectronics, photonics and optical data storage. In this work, we have studied the nonlinear optical properties of two types of compounds; organic molecules based on BODIPY and organometallic complexes based on ruthenium (II) and iron (II). For this, the experimental techniques used were based on SHG, THG and onZ-scan techniques. For this study, we used a pulsed picosecond laser delivering two wavelengths: 1064 nm and 532 nm. 1064 nm for SHG and THG techniques and 532 nm for Z-scantechnique were used, respectively. The results obtained are interesting and original and show that the nonlinear optical response of organic molecules based on BODIPY depends in particular on the number of electron donor groups. The same behavior has been observed in the case of organometallic complexes based on ruthenium (II) and iron (II), highlighting the modulation of the nonlinear optical response as a function of the nature of the transition metal used (Ru ( II) or Fe (II)) and the nature of the ancillary ligands around the organometallic moiety (Ru (II)).

No description available.

Depuis plusieurs décennies, les générateurs forts courants sont utilisés dans différents domaines comme l’étude des matériaux, la radiographie ou la fusion par confinement inertiel. Ces générateurs sont capables de délivrer des impulsions de courant de plusieurs millions d’ampères avec des fronts de montée inférieurs à la microseconde. Plusieurs projets à travers le monde ont, aujourd’hui, pour but d’améliorer encore et encore le gradient de courant des impulsions transmises à la charge. De nombreux schémas d’amplificateurs de puissance, dont le rôle est de jouer à la fois sur l’amplitude du courant de charge et sur son temps de montée, ont ainsi été testés. Le multiplicateur de courant dynamique (DLCM pour Dynamic Load Current Multiplier) fait partie de ces concepts novateurs permettant de contourner les limitations des générateurs de puissances pulsées actuels. Il est composé d’un réseau d’électrodes (servant d’autotransformateur), d’un extrudeur de flux dynamique (basé sur l’implosion d’un réseau de fils cylindrique) et d’un commutateur à fermeture sous vide. Dans la thèse, le principe de fonctionnement du DLCM est analysé d’un point de vue théorique par le biais de simulations de type circuits électriques et magnétohydrodynamiques. Une étude spécifique portant sur l’organe principal du DLCM est réalisée. Il s‘agit du commutateur à fermeture sous vide. Ainsi, après une phase de dimensionnement à l’aide d’outils de simulations électrostatiques, deux versions de commutateurs sont validées expérimentalement dans des conditions proches de celles d’un tir très fort courant. Enfin, des tirs sur le générateur SPHINX du CEA Gramat, capable de délivrer une impulsion de courant de 6MA en 800ns (sur charge Z-pinch), sont exposés pour retracer l’évolution du dispositif. Les résultats probants obtenus permettent, au final, de valider le concept DLCM connecté à une charge de type compression isentropique. / For several decades, high power generators are used in various fields such as materials research, radiography or inertial confinement fusion. These generators are capable of delivering current pulses of several millions of amperes with rise times below 1 microsecond. Several projects around the world are, today, trying to improve again and again the current gradient of pulses delivered to the load. Many concepts of power amplifiers, whose role is to optimize both the amplitude of the load current and its rise time, were tested. The Dynamic Load Current Multiplier (DLCM) is one of those innovating concepts used to overcome the existing pulsed power generators limitations. It is made up of concentric electrodes (for autotransformer), a dynamic flux extruder (based on the implosion of cylindrical wire array) and a vacuum closing switch. In this these, the operating principle of the DLCM is theoretically analyzed through electrical and magneto hydrodynamic simulations. A specific study of the DLCM key component is performed. This is the vacuum closing switch. Thus, after a design phase using electrostatic simulation tools, two versions of switches are experimentally validated in conditions similar to those of a very high current shot. Finally, shots on the SPHINX facility located at the CEA Gramat, capable of delivering a current pulse of 6MA in 800ns (on Z-pinch load), are exposed to trace the evolution of this device. The convincing results are used, ultimately, to validate the DLCM concept connected to an isentropic compression experiment load.

In this thesis I propose that the representation of the prison is an untapped and valuable resource for non-traditional representations of the queered male, homo-sex and sexualities. I draw together texts on prison and sexuality from the 1800s to the 2000s in order to discuss the representation of prison in light of what it adds to a wider historical understanding of sexuality. The thesis is broadly chronological in form, analysing academic and theoretical texts in context alongside popular cultural representations. I reassess the ways in which sexuality is viewed and understood over time, and place homosexuality within the framework of wider male sexuality as represented in the prison. I theorise a re-imagining of homosexuality within normative male sexuality and I challenge the concept of ‘situational sex' through the complex issues behind understandings of sex in prison. My research methodology includes close textual analysis of representations of prison in literature, film and television alongside academic and theoretical texts on sexuality, gender and queer theory. Each chapter focuses on specific cultural texts, including Against the Law (1957), Birdman of Alcatraz (1962) Short Eyes (1977), Scum (1977, 1979) and Oz (1997-2003). By drawing the representations and the theories together I am able to provide a re-reading of the texts within a recognition of sexual fluidity and the reclassification of heterosexual males and gender hierarchies. In my research I argue that the representation of sex in prison re-writes sexuality and contributes to a reading of the queering potential of the cultural representation of prison. With this method I challenge conventional understandings of sexuality as well as perceptions of how male sexuality is viewed in popular culture. I argue that the cultural representation of the prison is a site of queer potentiality in form, idea and context and is a means to re-imagine male sexuality.