L'ARN génomique du Virus de l'Immunodéficience Humaine-1 (VIH-1) est multifonctionnel. Il constitue le génome encapsidé dans les virions et sert d'ARN messager pour la traduction des protéines virales Gag et Gag-Pol. La traduction de ces protéines dépend exclusivement de la machinerie traductionnelle cellulaire et est initiée par deux mécanismes différents : l'initiation canonique dépendante de la coiffe et l'initiation par entrée interne des ribosomes (IRES). Le VIH-1 présente deux IRES, l'un dans la région 5' non traduite (5'-UTR) qui est stimulé en phase G2/M du cycle cellulaire et l'autre dans la région codante de Gag. Ce dernier permet l'initiation de la traduction sur deux AUG en phase et conduit à la production de la protéine Gag pleine longueur mais également à la production d'une isoforme alternative de Gag, tronquée en région N-terminale. Le rôle de cette isoforme reste mal connu. Toutefois la mutation du second AUG chez VIH-1 et donc la suppression de la seconde isoforme de Gag provoque une diminution importante du taux de la réplication virale. La conservation structurelle et fonctionnelle de l'IRES Gag parmi les lentivirus suggère un rôle important de cette isoforme et de l'IRES gag dans le cycle viral. Nos travaux visent à comprendre à un niveau moléculaire les relations hôtes-pathogènes lors de la traduction des messagers viraux. Je me suis particulièrement intéressée aux rôles de la sous unité ribosomale 40S et de l'hélicase cellulaire DDX3 dans l'initiation de la traduction de la polyprotéine Gag du VIH-1. La première partie de ma thèse est consacrée à l'étude de l'interaction entre la sous unité ribosomale 40S et l'IRES gag du VIH-1. Par l'utilisation d'approches complémentaires, nous avons pu démontrer la présence de deux sites distincts de liaison au ribosome qui sont présents à proximité des deux codons d'initiation. Nous avons ensuite évalué à la fois in vitro et in cellulo (en collaboration avec l'équipe de T. Ohlmann, CIRI-ENS-Lyon) l'effet de la délétion de chacun des sites de liaison au 40S sur l'efficacité de traduction de la polyprotéine Gag. Nos résultats valident l'importance fonctionnelle des sites de liaison au ribosome pour une production optimale des deux isoformes de la polyprotéine Gag. La seconde partie de mon travail a consisté à définir le rôle de DDX3 dans l'initiation « coiffe-dépendante » de la traduction de la polyprotéine Gag. DDX3 est une hélicase à ARN à boîte DEAD impliquée dans de nombreux processus cellulaires tels que la régulation du cycle cellulaire et la réponse immunitaire innée mais également dans tous les aspects du métabolisme de l'ARN comme la transcription, l'épissage, l'export nucléaire ou encore la traduction. Plus récemment, il a été montré que DDX3 est nécessaire à la traduction de l'ARN génomique du VIH-1, cependant son rôle exact n'a pas encore été défini. Nous avons purifié une forme recombinante de la protéine en fusion avec la MBP (Maltose Binding Protein) et effectué des cinétiques enzymatiques afin de caractériser ses propriétés biochimiques. Contrairement à ce qui a été précédemment décrit, nos résultats montrent que DDX3 possède une activité ATPase strictement ARN-dépendante avec des constantes cinétiques similaires à celles de son homologue chez la levure, Ded1p. Nous avons également évalué l'activité hélicase de la protéine en présence de substrats de longueur et de nature variables (duplex ARN/ARN ou des hétéroduplex ADN/ARN). D'un point de vue fonctionnel, nous avons réalisé une première série d'expériences qui confirme la stimulation exercée par DDX3 sur la traduction de Gag in vitro. Ces résultats permettent d'envisager la caractérisation biochimique fine des interactions DDX3-ARN viral ainsi que de disséquer le rôle de DDX3 dans l'expression du génome viral. / The Human Immunodeficiency Virus (HIV) genomic RNA is multifunctional. It acts both as a genome that is packaged within virions and as messenger RNA translated to yield the Gag and Gag-Pol polyproteins. The translation of these proteins relies exclusively on the cellular translation machinery and is initiated through two mechanisms: the canonical cap-dependent initiation pathway and the use of internal ribosome entry sites (IRESes). HIV-1 has two IRESes, one located within the 5' UTR (5' UnTranslated Region) that is stimulated during the G2/M phase of the cell cycle, and the other embedded within the Gag polyprotein coding region. The later drives translation initiation from two AUG in frame and results in the production of the full-length Gag protein but also of an additional N-terminally truncated Gag isoform. Few things are known about this isoform, but the mutation of the second AUG causes a significant decrease in the rate of viral replication. The structural and functional conservation of Gag IRES among lentiviruses suggests an important role of this isoform and thus of the IRES in the viral cycle. Our work aims to understand at a molecular level the host-pathogen relationships in the translation of the viral messenger RNA. My work focused on the roles of the 40S ribosomal subunit and of the cellular helicase DDX3 in the translation initiation of Gag. During the first part of my Phd, I studied the interaction between the 40S ribosomal subunit and HIV-1Gag IRES. Following complementary approaches, we evidenced two distinct ribosome binding sites present close to the two the initiation sites of Gag. Then, we evaluated the effect of each 40S binding site deletion on Gag translation efficiency, both in vitro and in cellulo (in collaboration with the team of T. Ohlmann, CIRI-ENS-Lyon). Taken together, our results confirm the functional relevance of the two ribosomal binding sites to ensure optimal production of the two Gag isoforms. The second part of my Phd project aims to define the role of DDX3 in the translation initiation of Gag. DDX3 is a RNA DEAD-box helicase involved in many cellular processes such as cell cycle regulation and the innate immune response but also in all aspects of RNA metabolism such as transcription, splicing, mRNA nuclear export and translation. Recently DDX3 has been shown to favor HIV-1 Gag translation. To define its role, we first purified a recombinant form of the protein and performed kinetic experiments to analyze its biochemical properties. Contrary to what has been previously described, MBP-DDX3 displays a strictly RNA-dependent ATPase activity with kinetic constants similar to those displayed by its yeast counterpart Ded1p. We next evaluated MBP-DDX3 helicase activity towards RNA duplexes or RNA/DNA hybrids, with different length and single strand overhangs. Our preliminary results indicate that DDX3 alone is sufficient to enhance Gag translation in our in vitro system which paves the way to fine biochemistry experiments such as reconstruction of functional initiation complexes assembled onto Gag RNA and evaluation of its role on Gag RNA structure.

A dissertação traz uma aproximação entre os poetas simbolistas Alphonsus de Guimaraens e Georges Rodenbach por meio da análise dos temas da cidade morta e da noiva morta. Inicialmente, é feita uma leitura panorâmica da obra em verso e prosa do poeta mineiro, em que se pontua a discussão acerca da religiosidade em sua produção, a fim de mostrar que a presença desse tema está a serviço de um projeto estético consciente e contribui com a criação de uma atmosfera de mistério comum às cidades mortas e de devoção à amada morta, da mesma forma como ocorre no romance Bruges-la-morte. Nesse romance de Georges Rodenbach, a cidade morta aparece como uma espécie de entidade mística, e sua imagem confunde-se com a imagem da mulher morta, num jogo de espelhamentos. Baseado, em especial, no conceito de espelhamento de Starobinski, este estudo pôde evidenciar nas obras de Alphonsus e Rodenbach a percepção das cidades como estados de alma e a imagem da noiva morta como consequência dessa condição anímica. Essa proximidade entre as obras dos dois autores é evidência de como Alphonsus poderia ter se apropriado de temas advindos da obra de Rodenbach, da qual ele era leitor. Isso deixa em aberto a possibilidade de certos temas conhecidos da obra de Alphonsus, normalmente associados à sua vida pessoal, advirem da influência que sofreu das tendências a ele contemporâneas da poesia e prosa europeia. / The dissertation brings an approximation between the Symbolist poets Alphonsus de Guimaraens and Georges Rodenbach through the analysis of the themes of the dead city and the dead bride. Initially, a panoramic reading of the works in verse and prose of the Brazilian poet is done, in which a discussion concerning religiousness in his work is pointed out with the intention of showing that the presence of such theme serves a conscious aesthetic project and contributes with the creation of a mysterious atmosphere, which appears both in the dead cities and in the devotion to the dead loved one, just like it happens in the novel Bruges-la-morte. In this novel by Georges Rodenbach, the dead city appears as a kind of mystical entity and its image mixes with that of the dead bride, in a mirroring game. Based mainly on Starobinskis concept of mirroring, this study was able to evidence the perception of the cities as states of mind and the image of the dead bride as a consequence of such psychic condition in the works of Guimaraens and Rodenbach. These proximities between the works of both authors is evidence of how Guimaraens could have appropriated themes from the works of Rodenbach, of whom he was a reader. That leaves open the possibility that certain themes known in the works of Guimaraens, which are usually associated with his personal life, may have come from the influence he suffered from the European poetry of his time.

Chez Arabidopsis thaliana, le silencing transcriptionnel est associé notamment aux modifications post-traductionnelles des queues des histones et à la méthylation des cytosines en contexte CG, CHG et CHH (où H peut être indifféremment T, A ou C). Plusieurs voies indépendantes conduisent à la méthylation de l’ADN en tout contexte via les méthyltransférases. A contrario, ROS1, une ADN déméthylase, « élague » les profils de méthylation et prévient ainsi d’une hyperméthylation du génome. Or, de façon intéressante, plusieurs mutants impliqués dans les voies de méthylation de l’ADN voient l’expression du gène ROS1 diminuer, ce qui trahit l’existence d’une boucle de rétrocontrôle négative entre les voies de méthylation et de déméthylation de l’ADN. Nous avons donc réalisé un crible génétique afin d’identifier un régulateur de l’expression de ROS1. Pour cela, nous avons utilisé une lignée pROS1:GUS constituée du gène rapporteur de la glucuronidase sous contrôle du promoteur de ROS1. Dans le fond mutant nrpd1a-4, le gène de ROS1 et de la glucuronidase sont sous-exprimés. Le crible consiste alors à identifier un mutant qui relâche l’expression de la glucuronidase et de ROS1 dans le fond mutant nrpd1a-4. Six mutants présentent une expression de la glucuronidase plus forte que le témoin pROS1:GUS dans le fond nrpd1a-4. Cependant, contrairement à ce qui était attendu, l’expression de ROS1 endogène est plus basse encore que chez pROS1:GUS dans le fond nrpd1a-4.Face à ses résultats, nous avons alors réorienté la thèse vers l’étude d’une voie de contournement du silencing des éléments répétés. En effet, lorsque l’on applique un stress thermique de 37°C durant 24h, l’on observe un relâchement du silencing de ces derniers. Toutefois, aucune modification épigénétique connue ne semble être impliquée. Pour étudier ce phénomène, nous disposons d’une lignée L5 qui, dans des conditions normales de culture, voit son transgène soumis aux mécanismes de silencing. Parce que la construction L5 comprend plusieurs répétitions de la glucuronidase sous contrôle du promoteur 35S, elle est alors assimilée à n’importe quel autre élément répété et, à ce titre, se retrouve être également exprimée après stress thermique. L’équipe a alors réalisé un crible sur cette lignée et a mis en évidence 3-1S, un mutant qui est déficient dans le relâchement du silencing à 37°C. Dans un premier temps, nous avons mis en évidence que le phénotype de 3-1S est dû à une mutation de RH35, une hélicase ARN à boîte DEAD. D’autre part, nos résultats montrent que le gène RH35 est exprimé plus fortement à 37°C et sa protéine présente, en outre, une relocalisation dans ces conditions de stress. RH35 serait, en fait, impliquée de manière plus globale dans le métabolisme des ARN en réponse au stress thermique et jouerait également un rôle dans la réponse au stress thermique et salin. / In Arabidopsis thaliana, transcriptional silencing is associated with histone tail post-translational modifications and cytosine modifications in CG, CHG and CHH contexts (where H can be indifferently T, A or C). Numerous independent pathways lead to DNA methylation in all contexts through méthyltransférases. Conversely, the DNA demethylase ROS1 “prunes” methylation profiles and prevents genome hypermethylation. Interestingly, several mutants which are involved in DNA methylation pathways present a decrease in ROS1 gene expression, what reveals the existence of a negative feedback loop between DNA methylation and demethylation pathways. A genetic screening was carried out in order to find a ROS1 regulator. To do this, pROS1:GUS line, which carries the glucuronidase reporter gene under ROS1 promoter, was used. In the nrpd1a-4 mutant, ROS1 and glucuronidase genes are underexpressed. The screen consisted to find a mutant which release glucuronidase and ROS1 gene expression in nrpd1a-4 mutant background. Six mutants presented a higher expression of the glucuronidase than the pROS1:GUS control in nrpd1a-4 background. However, unlike what it was expected, endogene ROS1 expression is even lower than what we have for pROS1:GUS in nrpd1a-4 background.In view of these results, the thesis was redirected toward the study of the silencing circumvention pathway of the repeated elements. Indeed, when heat stress at 37°C during 24h is applied, a release of silencing is observed for repeated elements. Nevertheless, no known epigenetic modifications seem to be involved. To study this phenomenon, we used a L5 line. Its transgene is silenced in standard conditions. Because L5 construct is composed by several glucuronidase repetitions under 35S promoter, it is considered as any other repeated elements and, for this reason, it is also expressed after heat stress. The team performed a genetic screen on this line and found 3-1S, a mutant which is deficient in the release of silencing at 37°C. On the one hand, we demonstrated that 3-1S phenotype is due to a mutation in RH35 DEAD box RNA helicase. On the other hand, our results revealed that RH35 gene is expressed at 37°C and its protein is relocated in heat stress conditions. In fact, RH35 would be involved more globally in RNA metabolism and would play a role in heat and salt stress.

No description available.

A dissertação traz uma aproximação entre os poetas simbolistas Alphonsus de Guimaraens e Georges Rodenbach por meio da análise dos temas da cidade morta e da noiva morta. Inicialmente, é feita uma leitura panorâmica da obra em verso e prosa do poeta mineiro, em que se pontua a discussão acerca da religiosidade em sua produção, a fim de mostrar que a presença desse tema está a serviço de um projeto estético consciente e contribui com a criação de uma atmosfera de mistério comum às cidades mortas e de devoção à amada morta, da mesma forma como ocorre no romance Bruges-la-morte. Nesse romance de Georges Rodenbach, a cidade morta aparece como uma espécie de entidade mística, e sua imagem confunde-se com a imagem da mulher morta, num jogo de espelhamentos. Baseado, em especial, no conceito de espelhamento de Starobinski, este estudo pôde evidenciar nas obras de Alphonsus e Rodenbach a percepção das cidades como estados de alma e a imagem da noiva morta como consequência dessa condição anímica. Essa proximidade entre as obras dos dois autores é evidência de como Alphonsus poderia ter se apropriado de temas advindos da obra de Rodenbach, da qual ele era leitor. Isso deixa em aberto a possibilidade de certos temas conhecidos da obra de Alphonsus, normalmente associados à sua vida pessoal, advirem da influência que sofreu das tendências a ele contemporâneas da poesia e prosa europeia. / The dissertation brings an approximation between the Symbolist poets Alphonsus de Guimaraens and Georges Rodenbach through the analysis of the themes of the dead city and the dead bride. Initially, a panoramic reading of the works in verse and prose of the Brazilian poet is done, in which a discussion concerning religiousness in his work is pointed out with the intention of showing that the presence of such theme serves a conscious aesthetic project and contributes with the creation of a mysterious atmosphere, which appears both in the dead cities and in the devotion to the dead loved one, just like it happens in the novel Bruges-la-morte. In this novel by Georges Rodenbach, the dead city appears as a kind of mystical entity and its image mixes with that of the dead bride, in a mirroring game. Based mainly on Starobinskis concept of mirroring, this study was able to evidence the perception of the cities as states of mind and the image of the dead bride as a consequence of such psychic condition in the works of Guimaraens and Rodenbach. These proximities between the works of both authors is evidence of how Guimaraens could have appropriated themes from the works of Rodenbach, of whom he was a reader. That leaves open the possibility that certain themes known in the works of Guimaraens, which are usually associated with his personal life, may have come from the influence he suffered from the European poetry of his time.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-09-12T17:26:03Z No. of bitstreams: 1 juliapessoavarges.pdf: 2258766 bytes, checksum: 4e93cc17ecc6f9a7932f8f1bcd68d32e (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-10-04T12:35:53Z (GMT) No. of bitstreams: 1 juliapessoavarges.pdf: 2258766 bytes, checksum: 4e93cc17ecc6f9a7932f8f1bcd68d32e (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-10-04T12:36:12Z (GMT) No. of bitstreams: 1 juliapessoavarges.pdf: 2258766 bytes, checksum: 4e93cc17ecc6f9a7932f8f1bcd68d32e (MD5) / Made available in DSpace on 2016-10-04T12:36:12Z (GMT). No. of bitstreams: 1 juliapessoavarges.pdf: 2258766 bytes, checksum: 4e93cc17ecc6f9a7932f8f1bcd68d32e (MD5) Previous issue date: 2011-04-15 / Resumo: Esta dissertação de mestrado analisa os jogos eletrônicos a partir de seu potencial narrativo. A popularização dos consoles de videogames e a disseminação dos computadores pessoais e da Internet ao longo das duas últimas décadas facilitou o acesso a estes produtos tecnológicos, aumentando também o interesse acadêmico em tais jogos. Grande parte da bibliografia referente ao assunto gira em torno do debate Narratologia versus Ludologia; em que teóricos de vertentes opostas acreditam que os jogos eletrônicos podem ser compreendidos ou somente por seus aspectos lúdicos, diretamente ligados à ação do jogador (gameplay); ou apenas pelos narrativos. Ao longo da presente dissertação, apresentaremos os pensamentos dos principais ludologistas (Jesper Juul, Gonzalo Frasca, Espen Aarseth) e também dos narratologistas, dos quais a americana Janet Murray é a principal expoente. Nosso objetivo, ao descrever as duas vertentes, é demonstrar a necessidade de incorporá-las para uma compreensão mais ampla dos jogos eletrônicos, contrapondo o caráter excludente como as duas correntes teóricas vêm sendo concebidas. Desta forma, nossa hipótese é de que somente levando em conta o gameplay e o potencial narrativo é que se pode analisar os videogames no que Marie-Laure Ryan, Santaella e Galloway consideram sua característica mais distintiva: a interatividade. Para isto, utilizaremos o conceito de “narrativas interativas” de Ryan (2009), que propõe que a narratividade nos videogames é diretamente ligada ao gameplay, já que cada elemento narrativo é construído a partir de ações desempenhadas pelo jogador e materializadas no interior do jogo através de um avatar; e, por outro lado, cada ação a ser tomada é determinada pelo enredo narrativo que se forma. Assim, lúdico e narrativo são elementos inextricáveis para a compreensão dos jogos eletrônicos em todo potencial. Como exemplo desta tendência, analisaremos “Red Dead Redemption”, jogo para Xbox 360 criado pela Rockstar Games, que acreditamos agregar todas as características das “narrativas interativas” de Ryan. / This dissertation analyzes videogames from their narrative potential. The popularity of videogame consoles and the spread of personal computers and the Internet over the past two decades have facilitated the access to these technological products, also causing the academic interest in such games to increase. Much of the literature on the subject revolves around the debate “Narratology versus Ludology”, where theorists of opposing sides believe that electronic games can be understood either by their ludic aspects, directly related to the action of the player (gameplay), or only by its narrative characteristics. Throughout this thesis, we present the thoughts of the main Ludologists (Jesper Juul, Gonzalo Frasca, Espen Aarseth) and the Narratologists, of which Janet Murray is the principal exponent. Our goal in describing the two theories is to demonstrate the need to incorporate them both in order to achieve a broader understanding of electronic games, unlike the opposition between the two theoretical approaches proposes. Hence, our hypothesis is that it is only taking into account both gameplay and the narrative potential of videogames that one can analyze these games in which Marie-Laure Ryan, Santaella and Galloway consider its most distinctive feature: interactivity. To do so, we use Ryan’s concept of "interactive narratives" (2009), which proposes that the narrative in video games is directly related to gameplay, as each narrative element is constructed from actions taken by the player and materialized inside the game through an avatar, and, moreover, every action taken is determined by the narrative plot that is designed. As a consequence, ludic and narrative elements are inextricable to the understanding of electronic games in their full potential. As an example of this trend, we will analyze the game "Red Dead Redemption" for Xbox 360, created by Rockstar Games, which we believe aggregates all the characteristics of Ryan’s "interactive narratives".

The aim of this study is to assess to which extent the concept called the final girl can be applied to a character produced outside USA. To achieve this, I have used a Japanese film called Evil Dead Trap (Toshiharu Ikeda, 1988), where I have analyzed the character Nami and her relations to the conventions of the final girl. Some of the more common conventions are that the final girl do not engage in sex or use drugs such as cigarettes. The theoretical framework focuses on identifying and establishing the different conventions of the final girl by using two different researchers and their texts. The state of research was used to place the movie in a historical context. Because of this, the research used focused on Japanese horror cinema from the fifties to the nineties. When the framework was established, an analysis of the final girl was made. Throughout the analysis I saw that, apart from three exceptions, Nami followed the conventions of the final girl. The exceptions were that she did not survive the movie, she took drugs in the form of a cigarette and showed a lack of intellect when they arrived at the military base.

No description available.

I industriella miljöer är det avgörande att säkerställa människors säkerhet runt robotarmar för att förhindra allvarliga skador vid olyckor. Denna studie syftar till att utveckla ett realtidssystem för fara-detektering som använder datorseende och prediktiva modeller för att förbättra säkerheten. Genom att kombinera YOLOv8-algoritmen för objektigenkänning med Kalmanfiltrering (KF) och Dead Reckoning (DR) kan systemet upptäcka människors närvaro och förutsäga rörelser för att minska risken för olyckor. Det första experimentet visar att KF presterar bättre än DR, särskilt vid linjära rörelser, med lägre medelabsolutfel (MAE) och medelkvadratfel (MSE). Det andra experimentet visar att integrationen av KF med YOLOv8 resulterar i högre precision, noggrannhet och balanserad noggrannhet, även om återkallning fortfarande behöver förbättras. Dessa resultat indikerar att kombinationen av datorseende och prediktiva modeller har betydande potential att förbättra människors säkerhet. Ytterligare forskning och tester i olika scenarier är dock nödvändiga innan implementering i verkliga miljöer. / In industrial environments, ensuring human safety around robotic arms is crucial to prevent severe injuries from accidents. This study aims to develop a real-time hazard detection system using computer vision and predictive modeling techniques to improve safety. By combining the YOLOv8 object detection algorithm with Kalman Filtering (KF) and Dead Reckoning (DR), the system can detect human presence and predict movements to reduce the risk of accidents. The first experiment shows that KF outperforms DR, especially in linear movements, with lower Mean Absolute Error (MAE) and Mean Squared Error (MSE). The second experiment demonstrates that integrating KF with YOLOv8 results in higher precision, accuracy, and balanced accuracy, although recall still needs improvement. These findings indicate that combining computer vision with predictive modeling has significant potential to enhance human safety. However, further research and testing in diverse scenarios are necessary before real-world deployment.

L'apparente pérennité de la figure du zombie, sa résurrection périodique à des moments charnières de l'histoire et son évolution suggère qu'elle pourrait jouer un rôle symbolique au sein de la société où elle prend forme. Le mandat de cette étude consiste donc d'abord à dresser un portrait du zombie contemporain en clarifiant la provenance ainsi que les origines du mythe et en prenant bien soin de définir les caractéristiques récurrentes du monstre à travers les époques et nations. Ensuite, il tient à étudier trois différents films provenant de trois différentes époques soient : White Zombie (1932) de Victor Halperin, Dawn of the Dead (1978) de George A. Romero et 28 Days Later (2002) de Danny Boyle et Alex Garland. Ces films sont analysés en fonction de l'attitude du zombie, de ses caractéristiques, des motivations apparentes, de son pouvoir et impact sur la population. En somme, l'objectif vise ici à établir un portrait de la figure du zombie au cinéma, à donner un aperçu de son évolution, et à déterminer la nature du rôle, qu'il semble exercer sur la société représentée où il sévit.