Ce mémoire décrit les corps dolomitiques des zones de Ranero et El Moro (vallée de la Karantza, zone Cantabrique, NO de l’Espagne) et précise les variations temporelles et latérales de leurs attributs pétrographiques et géochimiques. Les corps dolomitiques sont portés par les calcaires Albiens, déposés sur la marge du bassin Basque-Cantabrique en période d’intense subsidence. Les dolomies sont formées par replacement et par cémentation, et précédées et suivies par divers types de ciment calcitique. L’étude pétrographique, minéralogique et géochimique (XRD, ICP, XRF, isotopes stables et Sr) est conduite le long de sections transverses sur les corps dolomitiques et permet de comparer les caractéristiques de plusieurs stades de circulations hydrothermales. Deux épisodes contrastés de dolomitisation sont identifiés. Les dolomies précoces sont ferreuses, très localement associées à une minéralisation de type MVT, appauvries en δ18O (de -14 à -10‰ V-PDB) et remplacent largement les calcaires massifs en générant des zebras. Les dolomies tardives sont non-ferreuses, plus sévèrement appauvries en δ18O (-19 to -15‰ V-PDB), et ne semblent pas remplacer le calcaire mais, au contraire, les dolomies précoces. Toutes ces dolomies sont pratiquement stœchiométriques (49.76 à 51.59 mole% CaCO3). Leurs inclusions fluides ont piégé des saumures de haute température (Th de 120 à 200°C). Leur contenu en Sr, radiogénique, suggère que les fluides responsables de la dolomitisation ont préalablement circulé à travers des roches silicoclastiques. La texture comme les propriétés pétrophysiques des dolomies sont largement affectées par les déformations cataclastiques et un épisode tardif de dédolomitisation (météorique).Le premier épisode de dolomitisation résulte probablement de l’expulsion des fluides issus de la compaction du bassin adjacent et de leur migration le long des fractures affectant la marge de la plateforme carbonatée Albienne. Ces fluides précoces étaient riches en Mg, Fe et peut-être légèrement acides pour pouvoir remplacer les calcaires. Les fluides responsables du deuxième épisode de dolomitisation sont pauvres en Fe, paraissent plus chauds et en relation avec une anomalie thermique. / This study documents the temporal and lateral variation in petrographic and geochemical signatures of fault-related dolomite bodies in the Ranero and El-Moro areas (Karrantza valley, Cantabrian mountains; NW Spain). These dolomite bodies are hosted in Albian carbonates, which were deposited at the margin of the Basque-Cantabrian Basin during an intense rift-related subsidence. Fluid circulations generated replacive and cementing dolomites, paragenetically predated and followed by various calcite cements. Petrography, mineralogical and geochemical systematics (XRD, ICP, XRF, stable and Sr isotopes) along sections cutting the dolostone bodies document successive hydrothermal stages. Two contrasting dolomite formation events are evidenced. Early dolomites are ferroan, locally associated with MVT mineralisation, δ18O depleted (-14 to -10‰ V-PDB) and mostly replace limestone producing abundant zebra lithotypes. Later dolomites are non-ferroan, severely δ18O depleted (-19 to -15‰ V-PDB), and do not replace limestones but rather previous dolomites. Dolomites are generally stoichiometric (49.76 to 51.59 M% CaCO3). Fluid inclusions record high temperature brines (Th 120 to 200°C). Sr isotope data suggest that the dolomitising fluids interacted upstream with siliciclastic lithologies. The dolomite fabric and its petrophysical properties are variably altered through cataclastic deformation and late (meteoric) dedolomitisation.The first episode of pervasive ferroan dolomitisation probably resulted from compactional dewatering of basinal fluids from the nearby Basque trough and hydrodynamic fluid flow along the fractures in the Albian carbonate platform. These early fluids must have been Mg, Fe-rich and slightly acidic (limestone-replacive). The second episode of very hot and localized dolomitisation may be related to a thermal anomaly and/or convective flow of Fe-poor fluids.

Un programme expérimental a été conçu afin d'étudier la dispersion des polluants sur un terrain complexe avec un accent mis sur des conditions stables qui restent délicates pour la modélisation numérique. Ce programme expérimental est mené sur le site du SIRTA dans la banlieue sud de Paris et consiste à mesurer en champ proche la turbulence et la dispersion des polluants. L'objectif de ce programme est de caractériser la structure fine de la turbulence et de la dispersion associée par des mesures à haute résolution temporelle et spatiale. Ensuite, ces mesures permettent de valider et d'améliorer la qualité de simulations CFD pour la turbulence et la dispersion sur un site fortement hétérogène. Le dispositif instrumental comprend 12 anémomètres ultrasoniques mesurant en continu la vitesse du vent et la température à 10 Hz, et 6 détecteurs à photo-ionisation (PID) mesurant la concentration de gaz à 50 Hz pendant des essais de traçage. Plusieurs périodes d’observations intensives (POIs) avec des rejets de gaz ont été réalisées depuis Mars 2012.Tout d'abord, une étude détaillée de l'écoulement du vent sur le site est réalisée, car l’écoulement doit être caractérisé et correctement simulé avant de simuler la dispersion des polluants. Cette étude est basée sur deux ans de mesures en continu et sur les mesures acquises durant les POIs. La forte anisotropie de la turbulence dans la couche de surface est caractérisée à l’aide du calcul des variances, des échelles de longueur intégrales et des spectres des trois composantes de la vitesse du vent. La propagation des structures turbulentes entre les capteurs est caractérisée en utilisant les corrélations de vitesse. Les spectres de vitesse montrent plusieurs pentes dans différentes zones de fréquence. En outre, l’analyse des données montre l’impact de l'hétérogénéité du terrain sur les mesures. La forêt au nord du site expérimental modifie la vitesse et la direction du vent pour un grand secteur nord. Il induit un fort cisaillement de la direction du vent et une décélération en dessous de la hauteur de la forêt. Les simulations numériques sont effectuées avec le code de CFD Code_Saturne en mode RANS avec une fermeture k-ε adaptée pour les écoulements atmosphériques et un modèle de canopée pour la forêt. Ces simulations reproduisent correctement les caractéristiques de l'écoulement moyen sur le site des mesures, en particulier l'impact de la forêt pour les différentes directions du vent et pour la stratification neutre et stable. Les résultats de simulation montrent aussi le cisaillement de direction du vent et l’augmentation de l’énergie cinétique turbulente induits par la forêt. Une étude de sensibilité montre que ces effets sur l'écoulement s’accentuent quand la densité foliaire augmente. L’étude de dispersion est réalisée pour plusieurs POIs. L’analyse des données de concentration montre la cohérence avec les mesures de campagnes précédentes réalisées dans des zones proches de la source. Les fluctuations de concentrations sont caractérisées à travers les séries temporelles, l'histogramme et l'analyse statistique des concentrations. Une zone inertielle peut également être identifiée dans les spectres de concentration. Ensuite, la dispersion des polluants est modélisée par les équations de transport pour la concentration et sa variance. La concentration moyenne est globalement en bon accord avec les mesures pour toutes les POIs étudiées. L’accord avec les mesures sur la position du maximum de concentration dépend de la précision de la rotation du vent simulée en-dessous de la hauteur de la forêt. Les fluctuations de concentration obtenues dans les simulations semblent être affectées de manière significative par la condition initiale et la modélisation du terme de dissipation. Une étude de sensibilité à la paramétrisation est ensuite présentée / An experimental program has been designed in order to study pollutants dispersion at a complex site with a focus on stable conditions, which are still challenging for numerical modelling. This experimental program is being conducted at the SIRTA site in a southern suburb of Paris and consists in measuring, in near field, the turbulence and the pollutants dispersion. The aim of this program is to characterize the fine structure of turbulence and associated dispersion through high temporal and spatial resolution measurements. Then, these measurements allow to validate and improve the performance of CFD simulation for turbulence and dispersion in a heterogeneous field. The instrumental set up includes 12 ultrasonic anemometers measuring continuously wind velocity and temperature at 10 Hz, and 6 photo-ionization detectors (PIDs) measuring gas concentration at 50 Hz during tracer tests. Intensive observations periods (IOPs) with gas releases have been performed since March 2012.First of all, a detailed study of flow on the site is made, because it must be characterised and properly simulated before attempting to simulate the pollutants dispersion. This study is based on two years of continuous measurements and on measurements performed during IOPs. Turbulence strong anisotropy in the surface layer is characterized by calculating variances, integral length scales and power spectra of the three wind velocity components. Propagation of turbulent structures between sensors has been characterized with velocity correlations. Energy spectra show several slopes in different frequency regions. Also, data analyses show impact of terrain heterogeneity on the measurements. The forest to the north of experimental field modifies wind velocity and direction for a large northerly sector. It induces a strong directional wind shear and a wind deceleration below the forest height. Numerical simulations are carried out using the CFD code Code_Saturne in RANS mode with a standard k-ε closure adapted for atmospheric flows and a canopy model for the forest. These simulations are shown to reproduce correctly the characteristics of the mean flow on the measurements site, especially the impact of the forest for different wind directions, in both neutral and stable stratification. Simulations results also show the directional wind shear and the turbulent kinetic energy increase induced by the forest. A sensitivity study has been made for various values of forest density and shows that the typical features of canopy flow become more pronounced as canopy density increases. Pollutants dispersion study are made for several IOPs. Concentration data analysis shows a consistency with previous measurements made in a near-source region where the plume scale is smaller than the large-scale turbulence eddies. Concentration fluctuations are characterized through concentration time series, histogram and statistical analysis. The internal subrange can be observed in the concentration spectra. Next, pollutants dispersion are modelled by transport equations for concentration and its variance. The mean concentrations show a good agreement with measurements in values for all the IOPs studied, except that the position of the concentration peak depends on the accuracy of simulated wind rotation below the forest height. The concentration fluctuations obtained from simulations seem to be affected significantly by the initial condition and the modelling of the dissipation term. A sensitivity study to the parameterisation is then presented

A l’issue d’un accident nucléaire, les produits de fission de l’uranium tel les iodes radioactifs sont dispersés dans l’environnement. L’homme est susceptible d’être exposé à ces éléments majoritairement via l’inhalation d’air et/ ou l’ingestion d’aliments contaminés. L’iode 131 est connu pour être responsable de l’augmentation de l’incidence du cancer de la thyroïde. Une des contremesures pour prévenir cette pathologie est l’ingestion de dose unique de comprimés d’iodure de potassium (KI) à fin de saturer la glande thyroïde par de l’iode stable et d’éviter ainsi l’accumulation de l’iode radioactif. Les scénarios de rejets réitérés d’iodes radioactifs lors des deux accidents majeurs Tchernobyl et Fukushima ont mis en évidence les limites de cette mesure, des prises répétées de KI pour protéger dans le temps les populations s’avèrent nécessaires. Dans la littérature on dispose de peu de données clinique et préclinique sur la prise répétée d’iode stable, quant à son usage ça n’a pas été décrit. La doctrine iode ainsi que l’autorisation de mise sur le marché (AMM) du KI envisage seulement la prise unique à renouveler exceptionnellement chez la population adulte. L’iode est connu pour être un élément clé de la fonction thyroïdienne, on jouant un double rôle à la fois de substrat de régulateur de la thyroïde. Si sa présence est indispensable à la formation des hormones thyroïdienne, son excès exerce un effet inhibiteur transitoire de cette synthèse connu sous le nom de l’effet Wolff-Chaikoff. Les hormones thyroïdiennes jouent un rôle majeur dans le développement et la fonction de presque tous les organes du corps (cerveau, cœur, os...), la moindre variation de leurs niveau peut impacter l’homéostasie du corps. Ainsi, il est difficile d’appliquer la prise répétée du KI en absence connaissances biologiques et toxicologiques. Pour combler ses lacunes et proposer une solution de prophylaxie répétée en cas d’exposition réitérée, le programme de recherche français PRIODAC : PRophylaxie répétée par l’IODe stable en situation ACcidentelle (ANR/RSNR), dont fait partie cette thèse vise à exploiter les modalités d’administration répétées du KI chez toutes les tranches d’âge (in utero, adulte et âgé), et d’évaluer la toxicologie de la prise répétée de KI sur les grandes fonctions physiologiques de l’organisme. Trois modèles de rats Wistar ont fait l’objet de ce travail de thèse : le modèle de référence rat adulte (âgé de 3 mois), le modèle à risque, organisme en développement (exposé durant la gestation) et un autre modèle à risque le rat âgé (âgé de 12 mois), ces trois modèles ont reçus 8 prise consécutive de KI 1mg/kg/24h. Les effets biologiques de ce traitement pendant 8 jours ont été évalués à long-terme (30 jours post-prophylaxie). Concernant, le modèle de référence ont n’a pas observé d’impact néfaste à long-terme de la prise répétée du KI (Lebsir, Cohen et al. 2018; Lebsir, Manens et al. 2018) par contre sur les modèles à risque plusieurs effets à long-terme ont été mis en évidence. Chez la progéniture exposée in utero, la coordination motrice ainsi que l’expression de quelques gènes clés du cerveau ont été négativement modifiées par le traitement. Chez le rat âgé la biochimie clinique, l’expression de quelques gènes clés de la fonction cardiovasculaire ainsi que le système rénine-angiotensine-aldostérone ont été significativement impacté par le traitement. En conclusion, les résultats obtenus montrent l’innocuité sur le plan toxicologique du KI administré à 1mg/kg toutes les 24h pendant 8 jours chez le modèle adulte et la nocuité de ce schéma prophylactique chez les modèles à risque in utero et âgé. Ces résultats ont été communiquées à la pharmacie centrale des armées (producteur et détentrice de l’AMM) afin de servir de données d’entrée pour des études de bonne pratique de laboratoire notamment pour le modèle adulte et également, afin de contribuées à l’évolution de la doctrine de l’iode en terme de radioprotection. / Following nuclear accidents, uranium fission products such as radioactive iodines are released into the environment. Humans are likely to be exposed to these elements mainly through inhalation of air and / or ingestion of contaminated food. Iodine 131 is known to be responsible for increasing the incidence of thyroid cancer. One of the available countermeasures is the ingestion of a single dose of potassium iodide (KI) tablets to saturate the thyroid gland with stable iodine and thus prevent the uptake of the radioactive isotope.Repeated releases of radioactive iodine during the two major accidents Chernobyl and Fukushima have highlighted the weaknesses of this measure, repeated intake of KI maybe necessary. In the literature there is little clinical and preclinical data on the repeated intake of stable iodine, regarding its use it has not been described. The iodine doctrine as well as the Marketing Authorization (MA) of the KI considers only the single taking, to renew exceptionally in the adult population. Iodine is known to be a key component of thyroid function, playing a dual role as both a substrate and a regulator of the thyroid. If its presence is essential for the synthesis of thyroid hormones, its excess exerts a transient inhibitory effect on this synthesis known as the Wolff-Chaikoff effect. Thyroid hormones affect the development and function of almost all organs of the body (brain, heart, bone ...), the slightest variation in their level can impact the homeostasis of the body. Hence, the toughness of applying repeated KI intake in the absence of biological and toxicological data. To fill this gap and find a solution in the event of repeated exposure, the French research program PRIODAC: repeated potassium iodide prophylaxis in accidental situation (ANR / RSNR), of which this thesis is part, aims to define the modalities of repeated administration of KI in all age groups (in utero, adult and elderly), and evaluate the biological consequences on the the body’s major physiological functions. Three models of Wistar rats were used in this work: the reference model adult rat (3 months), the first sensitive model offspring (exposed during gestation) and another sensitive model the older rat (12 months ), these three models received 8 consecutive intake of KI 1mg / kg / 24h. And the effects were assessed at long-term (30 days post-prophylaxis). On the reference model, there was no long-term adverse impact of repeated KI intake (Lebsir, Cohen et al. 2018; Lebsir, Manens et al. 2018). On the other hand, sensitive models reveal several long-term effects; the offspring exhibited impaired motor coordination and variation of the expression of some key brain genes. And in the elderly rat urinary biochemistry, expression of some key genes of the cardiovascular function, as well as the renin-angiotensin-aldosterone system were significantly impacted by the treatment. In conclusion, the results obtained show the toxicological safety of KI administered at 1 mg / kg every 24 hours for 8 days in the adult model, and the harm of this prophylactic scheme in sensitive models in utero and elderly. These results were sent to the French central pharmacy of armies and will serve as input data for good laboratory practice studies that eventually will contribute to the evolution of the iodine doctrine and KI MA.

No description available.

京都大学 / 新制・課程博士 / 博士(情報学) / 甲第24030号 / 情博第786号 / 新制||情||133(附属図書館) / 京都大学大学院情報学研究科知能情報学専攻 / (主査)准教授 宮崎 修一, 教授 岡部 寿男, 教授 阿久津 達也, 教授 湊 真一 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM

The transition from the Neoproterozoic to the early Cambrian world was a critical time in the co-evolution of life and the environment, when dramatic changes in the environment, including global glaciations and rising atmospheric oxygen levels precipitated the conditions in which variety of complex life emerged, diversified, and proliferated. However, questions persist regarding the timing and duration of those environmental events, and thus the extent of their direct effect on the evolution of life. These changing environmental conditions also produced unique taphonomic conditions that preserved a wide variety of organisms, and also produced unusual early diagenetic features that can be difficult to distinguish from fossilized organisms. In order to better resolve the link between life and the environment during the Neoproterozoic to Cambrian transition I present three chapters. The first chapter of this dissertation examines the carbonate clasts from a glacial diamictite deposited at the end of the Cryogenian Period in South China. By determining the source locality of those carbonate clasts using stable carbon and oxygen isotope compositions, we can better understand the extent of the Marinoan Glaciation and the intensity of its impact on the Earth's surface. In the second chapter of this dissertation, I investigate the changing chemical conditions of ocean waters following both the Marinoan glaciation and potentially one of the most intense disruptions to the carbon cycle in Earth History, the Ediacaran Shuram carbon isotope anomaly. I use Hg concentrations and stable isotope compositions to determine changes in sediment sourcing along with changes in marine redox, such as the development of photic zone euxinia. In the third chapter, I investigate the identity of Brooksella alternata, a purportedly cnidarian fossil that was later suggested to be a hexactinellid sponge fossil. My morphological and compositional analysis reveals B. alternata to be a concretion and thus a pseudofossil. / Doctor of Philosophy / The Earth experienced major changes between 635 and ~514 million years ago; the last global scale glaciation in the history of Earth ended, early animals arose, primary producers such as algae grew larger and more complex, and the first animals that were mobile and with hard skeletal parts evolved and diversified tremendously. Concomitantly, the environment on the Earth changed dramatically: the carbon cycle experienced one of the greatest disruptions in all of Earth history and the oceans and atmosphere gradually became more oxygen-rich, though areas with low levels of dissolved molecular oxygen and high concentrations of dissolved iron or hydrogen sulfide persisted, which may have impeded the diversification of complex animals. The exact timing and intensity of these changes are not fully resolved, and by investigating this time interval in the geologic record, we can better understand how the world changed and how life at the time responded. These changing environments also produced unique conditions which led to fossils being preserved in unique ways, though these conditions also produced non-biological structures that superficially resemble fossils. The first chapter of this dissertation investigates the source of clasts made of carbonate rock from a glacial diamictite (the poorly sorted mixture of the fine-grained and coarse-grained deposits left behind as glaciers recede) in South China deposited at the end of the last global scale glaciation about 635 million years ago. By determining the source, we can evaluate how far glacial activity transported sediments. I found that the previously suggested source of these clasts does not match the geochemical fingerprint of the carbonate clasts. I propose that these carbonate clasts may have come from a source that has since become "extinct" because of glacial erosion, or they may have come from another continent (for example, India). These scenarios highlight the magnitude of the global glaciation. In the second chapter, I investigated the mercury concentrations and stable isotope compositions from organic rich shales deposited ~550 million years ago. Mercury is an emerging tool for evaluating the level of dissolved molecular oxygen in ancient oceans. In this study, I found evidence of locally complex marine oxygen levels, including evidence for photic zone euxinia, meaning waters where oxygen was absent and hydrogen sulfide was present. Such conditions are toxic to animals and may have delayed the diversification of complex animal life. In the final chapter, I analyzed the ~503 million-year-old fossil Brooksella alternata. It was first described more than 100 years ago as a jelly-fish fossil. More recently it was suggested to be a sponge fossil (though it has been ascribed many other identities). Based on morphological analysis of a large collection, I determined that Brooksella alternata is not a fossil but rather a concretion with unusual shape.

Yes / Objectives: We compared δ15N and δ13C values from bone and dentine collagen profiles of individuals interred in famine‐related and attritional burials to evaluate whether individuals in medieval London who experienced nutritional stress exhibit enriched nitrogen in bone and tooth tissue. Dentine profiles were evaluated to identify patterns that may be indicative of famine during childhood and were compared with the age of enamel hypoplasia (EH) formation to assess whether isotopic patterns of undernutrition coincide with the timing of physiological stress. Materials and Methods: δ15N and δ13C isotope ratios of bone collagen were obtained from individuals (n = 128) interred in attritional and famine burials from a medieval London cemetery (c. 1120–1539). Temporal sequences of δ15N and δ13C isotope profiles for incrementally forming dentine collagen were obtained from a subset of these individuals (n = 21). Results: Results indicate that individuals from attritional graves exhibit significantly higher δ15N values but no significant differences were found between burial types for the sexes. Analyses of dentine profiles reveal that a lower proportion of famine burials exhibit stable dentine profiles and that several exhibit a pattern of opposing covariance between δ15N and δ13C. EH were also observed to have formed during or after the opposing covariance pattern for some individuals. Conclusions: The results of this study may reflect differences in diet between burial types rather than nutritional stress. Though nutritional stress could not be definitively identified using bone and dentine collagen, the results from dentine analysis support previous observations of biochemical patterns associated with nutritional stress during childhood. / Division of Behavioral and Cognitive Sciences. Grant Numbers: BCS‐1261682, BCS‐1540208. Office of the Vice President for Research, University of South Carolina. Grant Number: SPARC Fellowship Grant

Seja $\\mathcal X=\\{\\mathcal X_t:\\, t\\geq0,\\, \\mathcal X_0=0\\}$ um passeio aleatório $\\beta$-estável em $\\mathbb Z$ com média zero e com taxas de saltos não-homogêneas $\\{\\tau_i^: i\\in\\mathbb Z\\}$, com $\\beta\\in(1,2]$ e $\\{\\tau_i: i\\in\\mathbb Z\\}$ sendo uma família de variáveis aleatórias independentes com distribuição marginal comum na bacia de atração de uma lei $\\alpha$-estável, com $\\alpha\\in(0,2]$. Nesta tese, obtemos resultados sobre o comportamento do processo $\\mathcal X_t$ para tempos longos, em particular, obtemos seu limite de escala. Quando $\\alpha\\in(0,1)$, o limite de escala é um processo $\\beta$-estável mudado de tempo pela inversa de um outro processo, o qual envolve o tempo local do processo $\\beta$-estável e um independente subordinador $\\alpha$-estável; chamamos o processo resultante de processo quase-estável. Para o caso $\\alpha\\in[1,2]$, o limite de escala é um ordinário processo $\\beta$-estável. Para $\\beta=2$ e $\\alpha\\in(0,1)$, o limite de escala é uma quase-difusão com medida de velocidade aleatória estudada por Fontes, Isopi e Newman (2002). Outros resultados sobre o comportamento de $\\mathcal X$ para tempos longos são envelhecimento e localização. Nós obtemos resultados de envelhecimento integrado e não-integrado para $\\mathcal X$ quando $\\alpha\\in(0,1)$. Relacionado à esses resultados, e possivelmente de interesse independente, consideramos o processo de armadilha definido por $\\{\\tau_{\\mathcal X_t}: t\\geq0\\}$, e obtemos seu limite de escala. Concluímos a tese com resultados sobre localização de $\\mathcal X$. Mostramos que ele pode ser localizado quando $\\alpha\\in(0,1)$, e que não pode ser localizado quando $\\alpha\\in(1,2]$, assim estendendo os resultados de Fontes, Isopi e Newman (1999) para o caso de passeios simples simétricos. / Let $\\mathcal X=\\{\\mathcal X_t:\\, t\\geq0,\\, \\mathcal X_0=0\\}$ be a mean zero $\\beta$-stable random walk on $\\mathbb Z$ with inhomogeneous jump rates $\\{\\tau_i^: i\\in\\mathbb Z\\}$, with $\\beta\\in(1,2]$ and $\\{\\tau_i: i\\in\\mathbb Z\\}$ is a family of independent random variables with common marginal distribution in the basin of attraction of an $\\alpha$-stable law with $\\alpha\\in(0,2]$. In this thesis we derive results about the long time behavior of this process, in particular its scaling limit. When $\\alpha\\in(0,1)$, the scaling limit is a $\\beta$-stable process time-changed by the inverse of another process, involving the local time of the $\\beta$-stable process and an independent $\\alpha$-stable subordinator; the resulting process may be called a quasistable process. For the case $\\alpha\\in[1,2]$, the scaling limit is an ordinary $\\beta$-stable process. For $\\beta=2$ and $\\alpha\\in(0,1)$, the scaling limit is a quasidiffusion with random speed measure studied by Fontes, Isopi and Newman (2002). Other results about the long time behavior of $\\mathcal X$ concern aging and localization. We obtain integrated and non integrated aging results for $\\mathcal X$ when $\\alpha\\in(0,1)$. Related to these results, and possibly of independent interest, we consider the trap process defined as $\\{\\tau_{\\mathcal X_t}: t\\geq0\\}$, and derive its scaling limit. We conclude the thesis with results about localization of $\\mathcal X$. We show that it localizes when $\\alpha\\in(0,1)$, and does not localize when $\\alpha\\in(1,2]$, extending results of Fontes, Isopi and Newman (1999) for the simple symmetric case.

Seja $\\mathcal X=\\{\\mathcal X_t:\\, t\\geq0,\\, \\mathcal X_0=0\\}$ um passeio aleatório $\\beta$-estável em $\\mathbb Z$ com média zero e com taxas de saltos não-homogêneas $\\{\\tau_i^: i\\in\\mathbb Z\\}$, com $\\beta\\in(1,2]$ e $\\{\\tau_i: i\\in\\mathbb Z\\}$ sendo uma família de variáveis aleatórias independentes com distribuição marginal comum na bacia de atração de uma lei $\\alpha$-estável, com $\\alpha\\in(0,2]$. Nesta tese, obtemos resultados sobre o comportamento do processo $\\mathcal X_t$ para tempos longos, em particular, obtemos seu limite de escala. Quando $\\alpha\\in(0,1)$, o limite de escala é um processo $\\beta$-estável mudado de tempo pela inversa de um outro processo, o qual envolve o tempo local do processo $\\beta$-estável e um independente subordinador $\\alpha$-estável; chamamos o processo resultante de processo quase-estável. Para o caso $\\alpha\\in[1,2]$, o limite de escala é um ordinário processo $\\beta$-estável. Para $\\beta=2$ e $\\alpha\\in(0,1)$, o limite de escala é uma quase-difusão com medida de velocidade aleatória estudada por Fontes, Isopi e Newman (2002). Outros resultados sobre o comportamento de $\\mathcal X$ para tempos longos são envelhecimento e localização. Nós obtemos resultados de envelhecimento integrado e não-integrado para $\\mathcal X$ quando $\\alpha\\in(0,1)$. Relacionado à esses resultados, e possivelmente de interesse independente, consideramos o processo de armadilha definido por $\\{\\tau_{\\mathcal X_t}: t\\geq0\\}$, e obtemos seu limite de escala. Concluímos a tese com resultados sobre localização de $\\mathcal X$. Mostramos que ele pode ser localizado quando $\\alpha\\in(0,1)$, e que não pode ser localizado quando $\\alpha\\in(1,2]$, assim estendendo os resultados de Fontes, Isopi e Newman (1999) para o caso de passeios simples simétricos. / Let $\\mathcal X=\\{\\mathcal X_t:\\, t\\geq0,\\, \\mathcal X_0=0\\}$ be a mean zero $\\beta$-stable random walk on $\\mathbb Z$ with inhomogeneous jump rates $\\{\\tau_i^: i\\in\\mathbb Z\\}$, with $\\beta\\in(1,2]$ and $\\{\\tau_i: i\\in\\mathbb Z\\}$ is a family of independent random variables with common marginal distribution in the basin of attraction of an $\\alpha$-stable law with $\\alpha\\in(0,2]$. In this thesis we derive results about the long time behavior of this process, in particular its scaling limit. When $\\alpha\\in(0,1)$, the scaling limit is a $\\beta$-stable process time-changed by the inverse of another process, involving the local time of the $\\beta$-stable process and an independent $\\alpha$-stable subordinator; the resulting process may be called a quasistable process. For the case $\\alpha\\in[1,2]$, the scaling limit is an ordinary $\\beta$-stable process. For $\\beta=2$ and $\\alpha\\in(0,1)$, the scaling limit is a quasidiffusion with random speed measure studied by Fontes, Isopi and Newman (2002). Other results about the long time behavior of $\\mathcal X$ concern aging and localization. We obtain integrated and non integrated aging results for $\\mathcal X$ when $\\alpha\\in(0,1)$. Related to these results, and possibly of independent interest, we consider the trap process defined as $\\{\\tau_{\\mathcal X_t}: t\\geq0\\}$, and derive its scaling limit. We conclude the thesis with results about localization of $\\mathcal X$. We show that it localizes when $\\alpha\\in(0,1)$, and does not localize when $\\alpha\\in(1,2]$, extending results of Fontes, Isopi and Newman (1999) for the simple symmetric case.

Dans cette thèse, nous étudions les effets d'un environnement stochastique et de l'utilisation d'une stratégie d'opting-out sur l'évolution de la coopération dans les jeux évolutionnaires. La thèse contient 8 articles, dont 6 sont déjà publiés dans des revues avec comité de lecture. Outre l'introduction, la thèse est divisée en deux parties, la partie 1 composée de 5 articles et la partie 2 de 3 articles. La partie 1 étudie l'impact de gains randomisés dans les jeux évolutionnaires. L'article 1 introduit les concepts de stabilité pour les jeux avec matrice de paiement aléatoire 2x2 dans des populations infinies avec des générations discrètes sans chevauchement dans un environnement stochastique. On y donne les conditions pour qu'un équilibre, sur la frontière ou à l'intérieur du simplexe des fréquences des stratégies, soit stochastiquement localement stable ou instable. L'article 2 étend les résultats de l'article 1 au cas où la valeur sélective est une fonction exponentielle du gain attendu suite à des interactions aléatoires par paires et montre que, de manière inattendue, le bruit aléatoire environnemental peut rompre un cycle périodique et favoriser la stabilité d'un équilibre intérieur. L'article 3 discute des effets de la sélection faible. Alors que les conditions de stabilité dans un environnement aléatoire reviennent aux conditions du cas déterministe lorsque l'intensité de la sélection diminue, les fluctuations aléatoires des gains peuvent accélérer la vitesse de convergence vers un équilibre stable sous une sélection plus faible. L'article 4 applique la théorie de la stabilité évolutive stochastique à un jeu randomisé de dilemme du prisonnier. On y montre que l'augmentation de la variance des gains de défection est propice à l'évolution de la coopération. L'article 5 étudie les jeux matriciels randomisés dans des populations finies et donne les conditions pour que la sélection favorise l'évolution de la coopération dans le contexte du jeu randomisé de dilemme du prisonnier. La partie 2 considère un jeu répété de dilemme du prisonnier dans le cas où un comportement d'opting-out est adopté par chaque joueur dans les interactions par paires. L'article 6 étudie la dynamique évolutive de la coopération et de la défection dans ce contexte et montre une possible coexistence à long terme, en supposant une population infinie et un équilibre rapide (en fait, instantané) dans les fréquences des paires. L'article 7 rapporte des résultats expérimentaux avec 264 étudiants universitaires utilisant la stratégie d'opting-out qui soutiennent la prédiction théorique d'une coexistence à long terme de coopération et de défection. L'article 8 étend l'analyse du modèle avec la stratégie d'opting-out au cas d'une population finie et fournit une preuve rigoureuse des deux échelles de temps pour les fréquences de coopération et de défection d'une part et les fréquences de paires de stratégies d'autre part. / In this thesis, we study the effects of a stochastic environment and the use of an opting-out strategy on the evolution of cooperation in evolutionary games. The thesis contains 8 articles, among which 6 are already published in peer-reviewed journals. Apart from the introduction, the thesis is divided into two parts, Part 1 made with 5 articles and Part 2 with 3 articles. Part 1 studies randomized payoffs in evolutionary games. Article 1 introduces stability concepts for 2x2 matrix games in infinite populations undergoing discrete, non-overlapping generations in a stochastic environment and gives conditions for an equilibrium, either on the boundary or in the interior of the simplex of all strategy frequencies, to be stochastically locally stable or unstable. Article 2 extends the results of Article 1 to the case where fitness is an exponential function of expected payoff in random pairwise interactions and shows that, unexpectedly, environmental random noise can break a periodic cycle and promote stability of an interior equilibrium. Article 3 discusses the effects of weak selection. While stability conditions in a random environment return to conditions in the deterministic case as selection intensity diminishes, random fluctuations in payoffs can accelerate the speed of convergence toward a stable equilibrium under weaker selection. Article 4 applies stochastic evolutionary stability theory to a randomized Prisoner's dilemma game and shows that increasing the variance in payoffs for defection is conducive to the evolution of cooperation. Article 5 studies randomized matrix games in finite populations and gives conditions for selection to favor the evolution of cooperation in the context of a randomized Prisoner's dilemma. Part 2 considers a repeated Prisoner's dilemma game with an opting-out behavior adopted by every player in pairwise interactions. Article 6 studies the evolutionary dynamics of cooperation and defection in this context and shows possible long-term coexistence, assuming an infinite population and fast (actually, instantaneous) equilibrium in the pair frequencies. Article 7 reports experimental results with 264 university students using the opting-out strategy that support the theoretical prediction of a long-term coexistence of cooperation and defection. Article 8 extends the analysis of the model with the opting-out strategy to the case of a finite population and provides a rigorous proof of the two-time scales for the frequencies of cooperation and defection on one hand and the frequencies of strategy pairs on the other.