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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Biofilmes anaeróbios: desenvolvimento e caracterização filogenética usando a hibridação in situ com sondas fluorescentes / Anaerobic biofilms: development and phylogenetic characterization using fluorescence in situ hybridization

Juliana Calábria de Araujo 11 May 2001 (has links)
Neste trabalho investigou-se o desenvolvimento de biofilmes anaeróbios em um sistema de laboratório chamado de \"Modified Robbins Device\" (MRD). O objetivo específico foi o de comparar a organização das células anaeróbias, particularmente daquelas que são comuns em lodos de esgoto, sobre superfícies hidrofílicas (vidro) e hidrofóbicas (polipropileno). A hibridação in situ com sondas fluorescentes complementares ao RNAr 16S específicas para domínio e grupos e a microscopia confocal de varredura a laser foram utilizadas para verificar a composição microbiana dos biofilmes, bem como do inóculo. Foram realizados dois tipos de experimentos, um com culturas puras de metanogênicas e outro com células oriundas de lodo granulado anaeróbio. As culturas puras de metanogênicas, Methanobacterium formicicum (DSM 1535), Methanosaeta concilii (DSM 3671) e Methanosarcina barkeri (DSM 800) foram usadas como inóculo para a formação dos biofilmes no interior do MRD durante 9 dias. Os resultados mostraram que as três espécies colonizaram ambas as superfícies após o segundo e sétimo dia de ensaio. No segundo experimento, o MRD foi inoculado com um consórcio microbiano anaeróbio e a formação do biofilme foi estudada durante 22 dias. As amostras dos biofilmes bem como aquelas retiradas do frasco-reservatório de células apresentaram composição microbiana semelhante, ambas foram dominadas por Archaeae metanogênicas hidrogenotróficas relacionadas com membros da família Methanobacteriaceae, já que foram detectadas com a sonda MB1174. Este grupo contribuiu com cerca de 44 a 90% do total de células coradas com DAPI e foi morfologicamente semelhante à Methanobacterium e Methanobrevibacter. As células detectadas com a sonda específica para membros da ordem Methanomicrobiales (MG1200) representaram cerca de 2 a 18,0% do total de células coradas com DAPI no frasco-reservatório e de 0,1 a 2,0% nas amostras dos biofilmes. Estas células foram ) morfologicamente semelhantes à Methanospirillum, também uma metanogênica hidrogenotrófica. Não foram detectadas células pertencentes à família Methanosarcinaceae, pois a hibridação com a sonda MSMX860 foi negativa. Células que hibridaram com a sonda específica para o Domínio Bacteria (EUB338) representaram cerca de 2 a 18% do total de células coradas com DAPI. Os resultados mostraram que as Archaeae metanogênicas hidrogenotróficas que foram predominantes no inóculo também dominaram os biofilmes que se desenvolveram em ambas as superfícies, vidro e polipropileno. Os dados desse trabalho sugerem que a hidrofobicidade do material suporte não influenciou o desenvolvimento e a composição microbiana dos biofilmes anaeróbios, considerando as condições específicas dos ensaios realizados. / In this study the development of anaerobic biofilms using a laboratory system called modified robbins device (MRO) were investigated. We were especially interested in comparing the organization of anaerobic cells, particularly those that are very common in domestic sewage sludge, in a hydrophilic (glass) versus a hydrophobic (polypropylene) surface. Fluorescence in situ hybridization (FISH) with domain and group speci fie probes that target intracell ular 16S rRNA and confocal laser scanning microscopy (CLSM) were used to investigate the microbial composition of both the inoculum and anaerobic biofilms. Two sets of experiments were carried, one with pure methanogenic organisms and the other with cells from a mesophilic anaerobic granular sludge. The pure methanogenic cultures, Methanobacterium formicicum (OSM 1535); Methanosaeta conci/ii (OSM 3671) and Methanosarcina barkeri (OSM 800) were used to seed the MRD to allow the development of biofilms over 9 days. The results showed that ali the three species were colonizing both surfaces after 2 and 7 days of experimental period. In the second experiment, the biofilm reactor was seeded with a microbial anaerobic consortium and biofilm forrnation was studied during 22 days. Biofilm and culture vessel samples showed nearly the same microbial composition, both were dominated by hydrogenotrophic methanogenic Archaea related to the Methanobacteriaceae as detected by the specific probe (MBI174). This group accounted for 44 to 90% of the OAPI-stained cells and morphologically resembled Methanobacterium and Methanobrevibacter. Cells detected with the Methanomicrobiales specific probe (MG 1200) accounted for 2 to 18.0% of the OAPI-stained cells in the culture vessel and 0.1 to 2.0% in the biofilm samples. These cells were morphologically similar to Methanospiriltum, also a hydrogenotrophic methanogen. No cells were detected by the Methanosarcinaceae specific probe (MSMX860). Cells which hybridized to the Bacteria specific probe (EUB338) accounted for the remaining 3 to 18% of the DAPI-stained cells. The results showed that the hydrogenotrophic methanogenic Archaea cells predominated in the inoculum and the biofilms that developed on both surfaces, glass and polypropylene. Our data suggest that the hydrophobicity of the support material did not influence the development and the microbial composition of anaerobic biofilms, considering specific conditions of the experiments.
12

Accélération de la méthode de Monte Carlo pour des processus de diffusions et applications en Finance / Improved Monte Carlo method for diffusion processes and applications in Finance

Hajji, Kaouther 12 December 2014 (has links)
Dans cette thèse, on s’intéresse à la combinaison des méthodes de réduction de variance et de réduction de la complexité de la méthode Monte Carlo. Dans une première partie de cette thèse, nous considérons un modèle de diffusion continu pour lequel on construit un algorithme adaptatif en appliquant l’importance sampling à la méthode de Romberg Statistique Nous démontrons un théorème central limite de type Lindeberg Feller pour cet algorithme. Dans ce même cadre et dans le même esprit, on applique l’importance sampling à la méthode de Multilevel Monte Carlo et on démontre également un théorème central limite pour l’algorithme adaptatif obtenu. Dans la deuxième partie de cette thèse,on développe le même type d’algorithme pour un modèle non continu à savoir les processus de Lévy. De même, nous démontrons un théorème central limite de type Lindeberg Feller. Des illustrations numériques ont été menées pour les différents algorithmes obtenus dans les deux cadres avec sauts et sans sauts. / In this thesis, we are interested in studying the combination of variance reduction methods and complexity improvement of the Monte Carlo method. In the first part of this thesis,we consider a continuous diffusion model for which we construct an adaptive algorithm by applying importance sampling to Statistical Romberg method. Then, we prove a central limit theorem of Lindeberg-Feller type for this algorithm. In the same setting and in the same spirit, we apply the importance sampling to the Multilevel Monte Carlo method. We also prove a central limit theorem for the obtained adaptive algorithm. In the second part of this thesis, we develop the same type of adaptive algorithm for a discontinuous model namely the Lévy processes and we prove the associated central limit theorem. Numerical simulations are processed for the different obtained algorithms in both settings with and without jumps.
13

O poder vai dançar de Tim Robbins: história, avanços e limites / Cradle will rock by Tim Robbins: history, advances and limits

Branco, Neyde Figueira 19 April 2011 (has links)
Esta pesquisa se utiliza do filme O poder vai dançar (Cradle will rock, 1999), dirigido por Tim Robbins, para entender a História, os avanços e limites de dois momentos históricos: a década de 1930 e a de 1990 nos Estados Unidos. Definido como uma história predominantemente verdadeira, o filme apresenta personagens e fatos reais e fictícios, que se alternam e se relacionam. Ele é composto por uma série de narrativas, aparentemente fragmentadas e desconexas, mas cujas relações são construídas em todo o seu decorrer. De modo geral, podemos dizer que o filme retrata a década de 1930, momento de potencial revolucionário na História dos Estados Unidos, uma vez que a crise econômica potencializou e tornou visíveis os problemas decorrentes do sistema capitalista. Em seu intento, o diretor se aproxima da concepção benjaminiana de História, à medida que, mais do que simplesmente reproduzir a narrativa desse período, opta por se apropriar de um momento explosivo do passado, carregado de elementos em comum com o presente, e utilizar a citação do passado como fonte de inspiração no combate presente. Ou seja, parte desse passado para na verdade dizer algo sobre a realidade em que está inserido, da década de 1990. Assim, ao pensar sobre esses contextos históricos, nos possibilita refletir sobre suas características, motivações e conseqüências. Para tanto, Tim Robbins se utiliza de elementos do teatro épico, e não apenas retrata os elementos históricos do período, mas busca principalmente provocar uma reflexão por parte da audiência. E tal reflexão vai além do entendimento da história, avança sobre questões como o reconhecimento pelo artista de sua condição de proletário da cultura e sobre o limite que se coloca entre fazer arte paga por empresas e a prostituição, entre outras. / This research makes use of the movie Cradle will rock (1999), directed by Tim Robbins, to understand the History, progresses and limits of two historical periods: the decades of 1930 and 1990 in the United States. Defined as a (mostly) true story, the movie presents real and fictional characters and facts, which are alternated and connected to each other. It has a series of narratives, aparently fragmented. However, its connections are built in the course of the movie. In general, we can say that the film portrays the decade of 1930, moment of revolutionary potential in the History of the United States, as a result of the economical crisis, that made visible all the problems deriving from the capitalistic system. In his intent, the director approaches the conception Benjamin has of the History, as he chooses to go beyond than only narrate the facts of the period and decides to appropriate of such an explosive moment of the past, replete of elements in common with the present, and use the citation of the past as a source of inspiration in the current battle. That is, uses the past in order to say something about the reality he experiences in the decade of 1990. In this manner, we can consider these historical periods and reflect on its characteristics, motivations and consequences. In order to do that, Tim Robbins makes use of elements of the epic theater, and not only depicts the historical elements of the period but also tries to provoke the audience and make them reflect about the facts and elements he exposes. These reflections surpass the understanding of the History and reaches questions such as the recognition of the artist of his condition of proletarian of the culture and the limit between making art sponsored by companies and the prostitution of the artist, among other.
14

O poder vai dançar de Tim Robbins: história, avanços e limites / Cradle will rock by Tim Robbins: history, advances and limits

Neyde Figueira Branco 19 April 2011 (has links)
Esta pesquisa se utiliza do filme O poder vai dançar (Cradle will rock, 1999), dirigido por Tim Robbins, para entender a História, os avanços e limites de dois momentos históricos: a década de 1930 e a de 1990 nos Estados Unidos. Definido como uma história predominantemente verdadeira, o filme apresenta personagens e fatos reais e fictícios, que se alternam e se relacionam. Ele é composto por uma série de narrativas, aparentemente fragmentadas e desconexas, mas cujas relações são construídas em todo o seu decorrer. De modo geral, podemos dizer que o filme retrata a década de 1930, momento de potencial revolucionário na História dos Estados Unidos, uma vez que a crise econômica potencializou e tornou visíveis os problemas decorrentes do sistema capitalista. Em seu intento, o diretor se aproxima da concepção benjaminiana de História, à medida que, mais do que simplesmente reproduzir a narrativa desse período, opta por se apropriar de um momento explosivo do passado, carregado de elementos em comum com o presente, e utilizar a citação do passado como fonte de inspiração no combate presente. Ou seja, parte desse passado para na verdade dizer algo sobre a realidade em que está inserido, da década de 1990. Assim, ao pensar sobre esses contextos históricos, nos possibilita refletir sobre suas características, motivações e conseqüências. Para tanto, Tim Robbins se utiliza de elementos do teatro épico, e não apenas retrata os elementos históricos do período, mas busca principalmente provocar uma reflexão por parte da audiência. E tal reflexão vai além do entendimento da história, avança sobre questões como o reconhecimento pelo artista de sua condição de proletário da cultura e sobre o limite que se coloca entre fazer arte paga por empresas e a prostituição, entre outras. / This research makes use of the movie Cradle will rock (1999), directed by Tim Robbins, to understand the History, progresses and limits of two historical periods: the decades of 1930 and 1990 in the United States. Defined as a (mostly) true story, the movie presents real and fictional characters and facts, which are alternated and connected to each other. It has a series of narratives, aparently fragmented. However, its connections are built in the course of the movie. In general, we can say that the film portrays the decade of 1930, moment of revolutionary potential in the History of the United States, as a result of the economical crisis, that made visible all the problems deriving from the capitalistic system. In his intent, the director approaches the conception Benjamin has of the History, as he chooses to go beyond than only narrate the facts of the period and decides to appropriate of such an explosive moment of the past, replete of elements in common with the present, and use the citation of the past as a source of inspiration in the current battle. That is, uses the past in order to say something about the reality he experiences in the decade of 1990. In this manner, we can consider these historical periods and reflect on its characteristics, motivations and consequences. In order to do that, Tim Robbins makes use of elements of the epic theater, and not only depicts the historical elements of the period but also tries to provoke the audience and make them reflect about the facts and elements he exposes. These reflections surpass the understanding of the History and reaches questions such as the recognition of the artist of his condition of proletarian of the culture and the limit between making art sponsored by companies and the prostitution of the artist, among other.
15

On two unsolved problems in probability

Swan, Yvik 08 June 2007 (has links)
Dans ce travail nous abordons deux problèmes non résolus en Probabilité appliquée. Nous les approchons tous deux sous un angle nouveau, en utilisant des outils aussi variés que les chaînes de Markov, les mouvements Browniens, les transformations de Schwarz-Christoffel, les processus de Poisson et la théorie des temps d'arrêts optimaux. Problème de la ruine pour N joueurs Le problème de la ruine pour $N$ joueurs est un problème célèbre dont la solution pour $N=2$ est connue depuis longtemps. Nous l'abordons premièrement en toute généralité, en le modélisant comme un problème d'absorption pour une chaîne de Markov. Nous obtenons les distributions associées à ce problème et nous décrivons un algorithme (appelé {it folding algorithm}) permettant de diminuer considérablement le nombre d'opérations nécessaires à une résolution complète. Cette étude nous permet de mettre en avant un certain nombres de relations de récurrence satisfaites par les probabilités de ruines associées à chaque état de la chaîne de Markov. Nous étudions ensuite une version asymptotique du problème de la ruine pour 3 joueurs. Nous utilisons les propriétés d'invariance des mouvements Browniens par transformations conformes pour décrire une résolution de ce problème via les transformations de Schwarz-Christoffel. Cette méthode dépasse le cadre strict du problème de la ruine pour 3 joueurs et s'applique à d'autres problèmes de temps d'atteinte d'un bord par un mouvement Brownien. Problème de Robbins Ce problème s'inscrit dans le cadre de la théorie des temps d'arrêts optimaux. C'est un problème d'analyse séquentielle dans lequel un observateur examine $n$ variables aléatoires indépendantes de manière séquentielle et doit en sélectionner exactement une sans rappel. L'objectif est de déterminer une stratégie qui permette de minimiser le rang moyen de l'observation sélectionnée. Nous décrivons un modèle alternatif de ce problème, dans lequel le décideur observe un nombre aléatoire d'arrivées distribuées suivant un processus de Poisson homogène sur un horizon fixe $t$. Nous prouvons l'existence d'une stratégie optimale pour chaque horizon, et nous montrons que la fonction de perte associée à cette stratégie est uniformément continue sur $R$. Nous décrivons une fonction de perte restreinte qui permet d'obtenir une estimation de la valeur asymptotique du problème, et nous obtenons la valeur asymptotique associée à des stratégies spécifiques. Nous obtenons ensuite une équation intégro-diffférentielle sur la fonction de perte associée à la stratégie optimale. Finalement nous étudions les valeurs asymptotiques du problème et nous les comparons à celles du problème en temps discret. Nous concluons cette thèse en décrivant des stratégies spécifiques qui permettent d'obtenir des estimations sur le comportement asymptotique de la fonction de perte.
16

The politics of place: photographing New York City during the New Deal

Graves, Lauren 06 October 2021 (has links)
My dissertation contemplates the role that New Deal era photographs played in developing a sense of place particular to New York City’s environs. I argue that photographers used the camera as a tool to cultivate the relationship between people and the urban landscape by focusing their lens on liminal and collective spaces within the metropolitan environment. My first chapter examines Helen Levitt’s survey of African-American, Latinx, and Italian children in East Harlem, sponsored by the Federal Art Project. My second chapter reviews a series produced under the same Project—Arnold Eagle and David Robbins’s study of the Jewish and Italian sections of the Lower East Side. My third chapter turns to Sid Grossman and Sol Libsohn’s chronicling of Irish and Italian second-generation immigrants in Chelsea, supported by the Photo League. In each chapter, I contend that the prominence of communal spaces within these images results in documents that can be read as an effort by photographer and subject alike to define their place within the contested sites of the urban street. Through this focus on vernacular spaces, these surveys disrupt ideals of belonging and work to document processes of place-making distinct to each occupier. Employing analytical lenses of cultural geography and phenomenology, I theorize the role of collective spaces within each series. These vernacular sites, propelled by their indistinct physical and social dimensions, hold slippery identities, shifting boundaries, and a collection of potential “owners.” Due to this ambiguity, these spaces hold an opportunity for collective emergent action. Throughout these series the photographers show neighborhood dwellers engaging collective spaces of the city to satisfy their quotidian needs. My dissertation examines how inhabitants, through acts of play, ritual, and embodied remembrance, transform these interstitial spaces into place. I consider the photographer’s role as folklorist, sociologist, and archeologist—as they survey how their subjects engage, occupy, and transform the local and ordinary spaces of their metropolitan landscape into places created and claimed by city-dwellers. In attending to the spatial dimension, I consider how photographs register and explore the lives of marginalized communities within the contested landscapes of New York City’s streets.
17

Messianisme, mysticisme et monothéisme : le RSI dans les œuvres de Tom Robbins

Buckwalter, Elvis 05 May 2009 (has links) (PDF)
Dans le contexte d'une société américaine où la religion occupe une place primordiale, une approche lacanienne des romans de Tom Robbins s'avère particulièrement utile pour dégager les thèmes directeurs de ses œuvres : le messianisme, le mysticisme et le monothéisme. Non seulement ces manifestations religieuses jouent un rôle central dans son œuvre romanesque, mais elles servent aussi à mieux exploiter les outils psychanalytiques développés par Jacques Lacan, et en particulier le Symbolique, l'Imaginaire et le Réel. Comment le RSI peut-il éclaircir le débat religieux dans les œuvres de Tom Robbins ou dans d'autres œuvres postmodernes ? Cette étude multidisciplinaire répond à cette problématique en se portant sur trois axes principaux. Premièrement, l'envergure de la messianité dans la société américaine donne lieu au phénomène littéraire que nous appelons " le sujet messianique ", se caractérisant par son ancrage topologique dans le Symbolique lacanien. Ensuite, la prévalence d'une approche mystique de la spiritualité dans les œuvres robbinsiennes s'exprime par une relation mystique entre un être divin d'une part, et le croyant d'autre part - rapport symbiotique propre à l'instance Imaginaire. Enfin, le Réel lacanien met en exergue l'impossibilité de la réconciliation structurale entre ces deux instances en explorant le thème du monothéisme dans les œuvres de Tom Robbins. Cette thèse a l'ambition non seulement de faire connaître un écrivain américain peu connu du public francophone, mais aussi de mieux définir l'articulation entre la religion, la psychanalyse et les romans de Tom Robbins
18

Flexible Multidimensional Item Response Theory Models Incorporating Response Styles

Stanley, Leanne M. 23 October 2017 (has links)
No description available.
19

Putování novinářského psance dobou dekadence a zvrácenosti: Hunter S. Thompson v kontextu Ameriky 60. a raných 70. let. / An Outlaw Journalist's Journey through an Era Decadent and Depraved: Hunter S. Thompson in the context of America of the 1960s and early 1970s.

Stárek, Jiří January 2015 (has links)
The thesis aims to explore the artistic personality of Hunter S. Thompson, one of the most distinctive cultural figures of post-war America, and his genesis as an author, journalist, and a counterculture idol of the 1960s. The era is now widely regarded as a turning point in contemporary American history as its deep-rooted values and norms were, over the course of a decade, gradually transformed by the young generation of social and political activists toward allegedly a more tolerant and liberal kind of community. Crucial in such an endeavor was the role of the countercultural movement that produced some of the most capable intellectual minds of the time, including Thompson. The paper thus analyzes the role and nature of the alternative culture in America as perceived by one of its most observant participants. Also, the thesis focuses on the author's role in establishing a new genre called New Journalism which can be linked with the era's countercultural efforts as well. In general, Thompson, in his texts, examines various phenomena surrounding the counterculture and provides us with a distinctive portrayal of the era's zeitgeist. However, unlike some of his contemporaries, he also remembers to examine numerous flaws and fallacies existing within contemporary American society, the American Dream...
20

Extraordinary Objects, Exceptional Subjects: Magic(al) Realism, Multivocality, and the Margins of Experience in the Works of Tom Robbins.

Byrnes, Sionainn Emily January 2015 (has links)
Through a critical examination of the works of Tom Robbins, this thesis interrogates the historical evolution and appropriation of the magic(al) realist tradition. In so doing, it situates Robbins’ writing within the framework of postmodernism, and explores the ontological implications inherent in Robbins’ use of magic(al) realist concepts and conventions. With a specific emphasis on the notion of cultural consciousness, this thesis analyzes the object- oriented cosmologies embodied and espoused in three of Robbins’ novels: Still Life with Woodpecker (1980), Skinny Legs and All (1990), and B is for Beer (2009). It unpacks the ideological figuration of various textual devices evident in Another Roadside Attraction (1971) and Even Cowgirls Get the Blues (1976) – particularly the gendered use of unreliable narrators – and, with reference to Jitterbug Perfume (1984), relates Robbins’ appropriation of the magic(al) realist tradition to the American counterculture movement of the 1960s and 70s. Employing poststructuralist, feminist, ecofeminist, and postcolonial discourses, this thesis ultimately seeks to position Robbins’ writing within the context of a radical emancipatory politics that views (and uses) literature as an ideological space in which to challenge, reinterpret, and democratize Western metanarratives.

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