Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

O presente trabalho tem como objetivo investigar a evolução temporal e espacial da camada limite planetária (CLP) na cidade de São Paulo durante o período noturno, utilizando o modelo LES. Foram simulados os campos tridimensionais das três componentes da velocidade do vento, temperatura potencial e concentração de monóxido de carbono (CO). Três propriedades da CLP noturna em São Paulo foram analisadas: a) Altura da CLP estável (CLE); b) Jatos de baixos níveis (JBN); c) Dispersão turbulenta de CO. Foi analisado também o ciclo diurno dos fluxos turbulentos de calor sensível e de CO na superfície. Inicialmente foi desenvolvido um procedimento de validação para avaliar o desempenho do modelo LES na simulação das propriedades da CLP convectiva, neutra e estável, utilizando como referência os resultados de simulações consagrados na literatura. A validação foi realizada comparando os perfis verticais médios de velocidade horizontal, temperatura potencial, variância das componentes da velocidade e as componentes da equação do balanço de energia cinética turbulenta (ECT). Os resultados dessa comparação indicam que o modelo LES atual é capaz de reproduzir todas as características dos processos turbulentos destes escoamentos. Foram realizados quatro experimentos numéricos com o intuito de investigar a evolução diurna da CLP para a situação de inverno em São Paulo, usando como condições de contorno, valores horários médios mensais de temperatura potencial e concentração de monóxido de carbono observados em superfície durante o mês de junho em São Paulo. Esses experimentos utilizaram também como condição de contorno a situação média nos dias de céu claro (sem nuvem) no mês de junho em São Paulo. O impacto da intensidade do vento também foi analisado especificando-se como forçante externa o vento geostrófico igual a 5 m/s e 10 m/s de oeste. Os dados utilizados neste trabalho foram medidos na plataforma micrometeorológica do IAG-USP (temperatura do ar e fluxo turbulento de calor sensível) e na estação Lapa da CETESB (concentração de monóxido de carbono e velocidade do vento). Os resultados destas 4 simulações indicam que a altura da CLE foi simulada pelo modelo LES de forma consistente com as forçantes e condições de contorno usadas, indicando que durante o mês de junho em São Paulo a altura da CLE varia entre 100 m e 275 m (médias) e 62 m e 203 m (dias de céu claro). Verificou-se também que a turbulência da CLE é mantida pela produção mecânica de ECT e dissipada majoritariamente pela destruição térmica. A dissipação molecular tem um papel secundário e o transporte turbulento não afeta as propriedades da CLE. Os resultados indicam que as formulações empíricas utilizadas neste trabalho são capazes de reproduzir de forma equivalente a ordem de magnitude da altura da CLE simulada para São Paulo. O melhor resultado foi obtido com h = 700 u*. As simulações do JBN indicaram que para São Paulo o mecanismo de ajuste inercial gera máximos da ordem de 7,1 m/s em torno de 210 m as 05:30 HL (forçante de 5 m/s) e de 14,5 m/s em torno de 420 m e as 05:30 HL (forçante de 10 m/s). Foi observada uma intensificação da turbulência acima do topo da camada estável. A evolução espacial e temporal da concentração de CO simulado pelo modelo LES apresenta um padrão de dispersão turbulento compatível com o esperado para o inverno em São Paulo. Finalmente, o modelo LES é capaz de reproduzir as principais características da evolução diurna do fluxo de calor sensível e de monóxido de carbono da superfície observados no mês de junho na cidade de São Paulo. / The main objective of this work is to investigate the temporal and spatial evolutions of the planetary boundary layer (PBL) in the city of São Paulo during the nighttime period, using a large-eddy simulation (LES) model. It was simulated the 3-dimensional fields of the three components of the wind speed, potential temperature and carbon monoxide concentration. Three properties of nocturnal PBL were investigated: a) PBL depth; b) Low level jet (LLJ) and c) Turbulent dispersion of CO. The diurnal evolution of the turbulent fluxes of sensible heat and CO was also analyzed. Initially, a validation procedure was carried considering the performance of LES model in to simulate the behavior of the PBL for convective, neutral and stable conditions using as reference simulation results available in the literature. The validation was performed by comparing the mean vertical profiles of horizontal wind, potential temperature, variance of wind speed components and the turbulent kinetic energy (TKE) equation components. They indicated that the actual version of LES model is capable to simulate the entire cycle of the PBL diurnal evolution over a homogeneous and flat surface. Once validated, the LES model was applied to simulate the PBL for a complete diurnal cycle over a flat and homogeneous surface with aerodynamic roughness length representative of a typical urban area of São Paulo. Four simulations were designed to investigate the nighttime PBL evolution for winter conditions in São Paulo, using as input, monthly average hourly values of potential temperature and monoxide carbon observed at the surface during June in São Paulo. The mean condition for clear sky days observed in June in São Paulo was also considered as input in these simulations. The impact of wind intensity was also analyzed by considering as the external forcing in these simulations a constant background geostrophic wind of $5$ and $10 ms^{-1}$ from West. The dataset used in this work was observed in the micrometeorological platform of IAG (air temperature and sensible heat flux) and at the surface station of environmental agency of the state of São Paulo (CETESB) locate at Lapa (CO and wind speed). The results indicate that the height of stable PBL was simulated consistently with the boundary conditions and external forcing, indicating that during June the in São Paulo the PBL height may vary from 100m (mean condition) and 62m (clear days condition) at the beginning of the night to 275m (mean condition) and 203m (clear sky conditions) at the end of nighttime. It was verified that the turbulence in the Stable PBL is maintained by the mechanical production of TKE and dissipated, mainly, by the negative thermal production. Molecular dissipation has a secondary role and turbulent transport of TKE does not affect the stable PBL. All the empirical formulations used here reproduced the order of magnitude of the stable PBL height. The best performance was obtained by $h = 700 u_*$ and $h = 0.5 \\sqrt{\\frac{u_* L}{\\left|fight|}}$. The simulated nocturnal LLJ indicated that for São Paulo the inertial oscillation yields a maximum intensity is $7.1 ms^{-1}$ at $210m$ and 05:30LT (forcing of $5 ms^{-1}$) and $14.5 ms^{-1}$ at $420m$ at 05:30LT (forcing of $10 ms^{-1}$). In both cases the LLJ intensified the turbulence at the top of the stable PBL. The simulated spatial and temporal evolution of the carbon monoxide concentration shows a pattern of turbulent dispersion consistent with the expected one for winter time in the city of São Paulo. Finally, LES model is able to reproduce the main features of the diurnal evolution of turbulent sensible heat and carbon monoxide fluxes at the surface for São Paulo during the winter.

Le mot « intime » en français suggère à la fois la convivialité au sein du cercle familial et la conscience intérieure de l’individu. Cette dualité essentielle de l’« intime », qui attire de nombreux écrivains français depuis des siècles, englobe un large éventail de thématiques littéraires, caractérisées par deux courants : la représentation de la vie familiale et les écrits autobiographiques. En règle générale, l’esthétique du naturalisme établie par Zola est considérée comme indifférente à l’égard de la littérature intime, développée par les écrivains romantiques. Cependant, certains de ses romans présentent les caractéristiques de l’écrit de l’intime du XIXe siècle. Dans cette étude, nous nous attacherons à établir le lien intérieur entre La Joie de vivre (1884), L’Oeuvre (1886) et Le Docteur Pascal (1893), trois romans exceptionnellement chargés d’éléments autobiographiques dans la série des Rougon-Macquart. L’intrigue de ces œuvres se déroule au sein du foyer et se concentre sur la psychologie des protagonistes, qui pourraient être définis comme alter ego de l’auteur. Dans La Joie de vivre, Zola projette son angoisse personnelle sur Lazare, jeune pessimiste souffrant de névrose. Dans L’OEuvre, l’auteur exprime sa vision esthétique à travers la création douloureuse du peintre Claude. Dans Le Docteur Pascal, véritable synthèse de la série, Zola manifeste enfin sa croyance optimiste à la vie à travers Pascal, son porte-parole. Le discours de l’« intime » chez Zola, aspect essentiel mais pourtant négligé de son œuvre romanesque, montre ainsi une mise en pratique du roman psychologique que l’auteur semble pourtant vouloir rejeter dans ses écrits « naturaliste ». / This study focuses on the two themes which the word “ intimacy ” refers to : firstly private life in a family, and secondly internal conscience of each individual. Due to the dual meaning of this word, two mainstream themes in the 19th century literature were formed : presentation of familial life and autobiography. In considering “ intimacy ” in naturalism, which have not been taken up until now, the autobiographic nature of Zola’s novels will be brought to light, as compared to autobiography in romanticism. This study examines and analyses three particularly autobiographical novels from total twenty volumes of the Rougon-Macquart series : La Joie de vivre (1884), L’OEuvre (1886) and Le Docteur Pascal (1893), considering those novels as a trilogy. Those three pieces clearly reflect the duality of “ intimacy ”, in depicting family life of the protagonist and, at the same time, the interior mind of Zola who appears as his alter ego. In La Joie de vivre, Zola, as a pessimist suffering neurosis, is depicted through Lazare. In L’OEuvre, Zola, based upon his experience as an art critic, demonstrates his artistic vision through the painter Claude. In Le Docteur Pascal, Zola’s confession full of optimism, contrary to the past after having concluded his works in the Rougon-Macquart series, is reflected in Pascal who is a philosophical scientist. This study analyses how Zola, who has been deemed as a naturalist in sharp contrast to an autobiographical writer, has taken the theme of “ intimacy ” into his novels through his own experience in private life, and how he produced the trilogy novels which are fiction and, at the same time, autobiographical pieces.

Les cellules T invariantes associées aux muqueuse (MAIT) sont des lymphocytes innés caractérisés par l'expression d'un récepteur des cellules T semi-invariant (iTCR) et restreints par la molécule du complexe majeur d'histocompatibilité de classe Ib, MR1. Chez l'homme, les cellules MAIT sont abondantes dans le sang (1 à 10%), l'intestin (3 à 5%) et le foie (20 à 40%) et réagissent contre des métabolites microbiens. En raison de leur rareté dans les souris de laboratoire classiques, les études sur les cellules MAIT murines ont été principalement effectuées sur des souris transgéniques (Tg) pour des TCR MAIT. Cependant, ces cellules MAIT Tg ne récapitulent pas de manière adéquate le phénotype des cellules MAIT humaines. Ici, nous décrivons une souche de souris congénique que nous avons générée qui possède des cellules MAIT qui ressemblent aux cellules MAIT humaines. Nous utilisons cet outil pour étudier les caractéristiques des cellules MAIT murines. L'étude de souches de souris consanguines d'origine sauvage montre que la souche CAST/Ei présente une fréquence des cellules MAIT nettement supérieur à celle retrouvée dans la souche C57BL/6. Un seul locus est impliqué et a été localisé dans la région TCRα. Ceci a permis la génération d'une souche "MAIT" congénique, qui ont été en outre croisé à une souris Tg pour un rapporteur GFP du facteur transcriptionnel RORγt sur la base de données antérieurs montrant que les MAITs humaines expriment ce facteur. Grâce à cet outil, nous montrons que les MAITs murines sont CD4−CD8−/lo, ont un phénotype mémoire effecteurs (CD44+) et coexpriment PLZF et RORγt. Ces MAITs murines sont orientées vers une localisation tissulaire (CCR6+CCR7−) et résident préférentiellement dans les tissus non lymphoïdes périphériques, y compris les poumons, le foie et la peau. Après stimulation du TCR, les MAITs produisent des cytokines TH1/2/17 et sont aussi activées par de antigènes bactériens (par exemple semi-purifié fraction bactérienne ou 5-OP-RU) d'une manière dépendant de MR1. Les MAITs ont une forte expression de récepteurs de cytokines (IL-7R, IL-18Rα, IL-12Rβ) et peuvent ainsi répondre à des cytokines innées. Lors d'une infection expérimentale des voies urinaires, les MAITs migrent vers la vessie et ont une activité protectrice anti-bactérienne. Au total, nos résultats démontrent que les cellules MAIT murines ressemblent étroitement à leurs homologues humains. Ce nouveau modèle murin sera un outil puissant pour faire avancer notre compréhension de la biologie des cellules MAIT en situation normale et pathologique. / Mucosal-associated invariant T cells (MAIT) are innate lymphocytes that express a semi-invariant T cell receptor (iTCR) and are restricted by the major histocompatibility complex (MHC) related molecule, MR1. In human, MAIT cells are abundant in the blood (1-10%), gut (3-5%), and liver (20-40%). They react against microbial-derived riboflavin metabolites that are common in bacteria and yeast. Due to the paucity of MAIT cells in classical inbred laboratory mice, studies on mouse MAIT cells were mostly performed in TCR-transgenic (Tg) mice. However, these Tg MAIT cells do not adequately recapitulate the phenotype of human MAIT cells. Herein, we present a recently generated congenic mouse strain harboring MAIT cells that closely resemble human MAIT cells and use this tool to study the characteristics of natural mouse MAIT cell. An analysis of wild-derived inbred mouse strains revealed that CAST/Ei strain has increased frequency of MAIT cells than C57BL/6 mice. This was linked to a locus on the TCRα region. Introduction of such locus into C57BL/6 mice generated a “MAIT” congenic strain, which were further crossed to Rorc(γt)-GfpTG reporter strain based on previous findings of RORγt expression on human MAIT cells. Using this tool, we show that natural mouse MAIT cells are CD4−CD8−/lo, display an effector memory phenotype (CD44+), and coexpress the transcription factors PLZF and RORγt. They exhibit tissue-homing properties (CCR6+CCR7−) and preferentially reside in peripheral non-lymphoid tissues, including lung, liver, and skin. Upon TCR ligation, MAIT cells produce TH1/2/17 type cytokines and react to bacterial-derived antigens (i.e. semi-purified bacterial fraction or 5-OP-RU) in an MR1-dependent manner. They have high expression of cytokine receptors (IL-7R, IL-18Rα, IL-12Rβ) and may respond to the corresponding innate cytokines. During experimental urinary tract infection, MAIT cells migrate to the bladder and display a protective anti-bacterial activity. Altogether, our results demonstrate that mouse MAIT cells resemble their human counterparts more closely than previously recognized and therefore this new mouse model will be a powerful tool for advancing our understanding of MAIT cell biology in health and disease.

Les modèles d'ascendance convective utilisés actuellement dans les paramétrisations de la convection ne prennent pas en compte explicitement le terme de pression non-hydrostatique, bien que son rôle fondamental soit documenté et expliqué depuis les années 70. Pour palier cette limitation, un modèle anélastique pronostique à deux colonnes d'une ascendance convective,prenant en compte explicitement le terme de pression non-hydrostatique, a été développé avec une géométrie 2D et 3D. Des fonctions de forme sont introduites pour réduire l'impact de la basse résolution horizontale. Trois paramètres doivent être prescrits : la hauteur et le rapport d'aspect de l'ascendance ainsi que la taille totale de la cellule convective. Le modèle est évalué en utilisant des profils de flottabilité idéalisés et constants, puis en s'appuyant sur une simulation LES de développement diurne de la convection profonde. Le comportement du modèle est en accord avec notre connaissance de la pression non hydrostatique à l'intérieur des nuages et de son rôle.L'ascendance simulée atteint rapidement un état stationnaire (5 min) en réponse au champ de flottabilité. Ainsi une version diagnostique a été développée, confirmant les résultats de la version pronostique. Sous le cœur de l'ascendance, un gradient de pression dirigé vers le bas est simulé permettant à l'ascendance de franchir la barrière d'inhibition convective. La future implémentation de ce modèle dans un schéma de convection, pour remplacer les formulations des modèles d'ascendance actuelles, devrait permettre d'augmenter la durée des évènements convectifs. / A simple anelastic 2-columns pronostic model of convective updraft accounting explicitly for thenon-hydrostatic pressure term is developed with 2D and 3D geometries. Shape fonctions areintroduced to overcome the low horizontal resolution. Three parameters must be prescribed :updraft depth, aspect ratio and total cell size. The model is tested for constant idealized buoyancyprofiles and successfully evaluated against a LES simulation of daytime development of deepconvection. The model behaviour agrees with our understanding of the non-hydrostatic pressurewithin clouds. The simulated updraft quickly reaches a steady state (5 min) in response to thebuoyancy field. So a diagnostic version has also been developped, confirming results of thepronostic version. Below an updraft core, a downward pressure gradient is simulated allowing theupdraft to overcome a barrier of convective inhibition. The further implementation of this modelwithin a convection scheme to replace a drag formulation of the updraft model, is expected toincrease the duration of convective events.

Cette thèse présente la technique de navigation magnéto-inertielle (MINAV) qui utilise les perturbations du champ magnétique en complément de capteurs inertiels (accéléromètres et gyromètres) pour la localisation d'un corps rigide en mouvement. On étudie des règles de conception, ainsi que des procédures opératoires nécessaires à la mise en pratique dans des conditions réelles. Un exemple de système complet, le "podomètre magnéto-inertiel", permettant la localisation d'un piéton évoluant dans des zones où le GPS est indisponible, est présenté.

Texte remanié de: Th. Doct.--Droit--Paris 2, 2002. / Bibliogr. p. 857-928. Index.

Thèse doctorat : Neurosciences : Nancy 1 : 2004. / Titre provenant de l'écran-titre.

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Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal