The modeling of spatio-temporal and multivariate spatial random fields has been an important and growing area of research due to the increasing availability of spacetime-referenced data in a large number of scientific applications. In geostatistics, the covariance function plays a crucial role in describing the spatio-temporal dependence in the data and is key to statistical modeling, inference, stochastic simulation and prediction. Therefore, the development of flexible covariance models, which can accomodate the inherent variability of the real data, is necessary for an advantageous modeling of random fields. This thesis is composed of four significant contributions in the development and applications of new covariance models for stationary multivariate spatial processes, and nonstationary spatial and spatio-temporal processes. The first focus of the thesis is on modeling of stationary multivariate spatial random fields through flexible multivariate covariance functions. Chapter 2 proposes a semiparametric approach for multivariate covariance function estimation with flexible specification of the cross-covariance functions via their spectral representations. The proposed method is applied to model and predict the bivariate data of particulate matter concentration (PM2.5) and wind speed (WS) in the United States. Chapter 3 introduces a parametric class of multivariate covariance functions with asymmetric cross-covariance functions. The proposed covariance model is applied to analyze the asymmetry and perform prediction in a trivariate data of PM2.5, WS and relative humidity (RH) in the United States. The second focus of the thesis is on nonstationary spatial and spatio-temporal random fields. Chapter 4 presents a space deformation method which imparts nonstationarity to any stationary covariance function. The proposed method utilizes the functional data registration algorithm and classical multidimensional scaling to estimate the spatial deformation. The application of the proposed method is demonstrated on a precipitation data. Finally, chapter 5 proposes a parametric class of time-varying spatio-temporal covariance functions, which are nonstationary in time. The proposed class is a time-varying generalization of an existing nonseparable stationary class of spatio-temporal covariance functions. The proposed time-varying model is then used to study the seasonality effect and perform space-time predictions in the daily PM2.5 data from Oregon, United States.

Les récepteurs couplés aux protéines G (RCPG) sont la famille de récepteurs membranaires la plus représentée chez les vertébrés, et la plus grande cible thérapeutique chez l'Homme. L'évolution du paradigme initial qui énonçait une stœchiométrie récepteur : protéine G : effecteur de 1 :1 :1 sera présentée sur le modèle des récepteurs aux chimiokines CXCR4 et CCR2. Grâce à la technique de transfert d'énergie par bioluminescence (BRET), les travaux réalisés durant cette thèse montrent (1) que c'est par un couplage alternatif de CXCR4 à Gα13 au lieu de la voie classique Gαi que les cellules de cancer du sein migrent pour former des métastases, (2) que la désensibilisation de CXCR4 implique le recrutement d'une combinaison définie de protéines (GRK et arrestines) permettant l'arrêt sélectif des multiples voies engagées en réponse à l'agoniste, et (3) que le protomère CXCR4 a un rôle déterminant dans l'engagement de la protéine Gαi et le recrutement de la β-arrestine par l'hétéro-oligomère CXCR4/CCR2 lorsque CCR2 est activé. Dans cette dernière et principale étude, les résultats montrent également que le dimère CCR2 peut s' assembler au dimère CXCR4 pour former un tétramère, et que l'activation de CCR2 influence la conformation du dimère CXCR4. Les phénomènes de coopérativité et d'activation asymétrique déjà rapportés pour cet hétérodimère pourraient donc impliquer l'interaction de quatre protomères. En conclusion les travaux effectués durant cette thèse démontrent une régulation supplémentaire de l'activité des récepteurs chimiokines au niveau de leur structure quaternaire, de leur signalisation, et de l'arrêt de cette signalisation. / G protein coupled receptors (GPCR) are the most represented cell surface receptors among vertebrates, and the major therapeutic target in humans. The initial paradigm stating a 1 :1 :1 stoichiometry for receptor :G protein :effector has evolved to a more complex model, as illustrated here with the example of the chemokine receptors CXCR4 and CCR2. Bioluminescence resonance energy transfer (BRET) was used to demonstrate that (1) CXCR4 is able to couple Gα13 instead of Gαi to promote breast cancer metastasis, (2) the multiple pathways engaged by stimulation of CXCR4 are selectively desensitized by the specific recruitment of a defined combination of proteins (GRKs and arrestins) and (3) the CXCR4 protomer plays a crucial role during Gαi engagement and β-arrestin recruitment by the CXCR4/CCR2 heterodimer upon CCR2 activation. In this last and main study, the results shown also demonstrate that CCR2 dimers could assemble with CX CR4 dimers into hetero-tetramers, and that CCR2 activation leads to a conformational change in the CXCR4 dimer. Former results showing cooperativity and asymmetric activation of a simple CXCR4/CCR2 heterodimer could then be applied to a tetramer. To conclude, the work done during this thesis demonstrates a more sophisticated regulation of chemokine receptors than previously suspected at 3 different levels: quaternary structure of the protomers, G protein signalling, and signalling termination

Les tâches quotidiennes exercées par les sapeurs-pompiers (SP) peuvent induire d’importantes contraintes musculo-squelettiques, des risques cardiovasculaires, du burnout et des blessures. L’objectif de ce travail doctoral est de caractériser la blessure des SP français et d’analyser l’influence de la pratique d’activité physique AP), du burnout, des stratégies de coping, des traits de personnalité, et des buts d’accomplissement dans l’occurrence des blessures. Nous défendons la thèse selon laquelle la blessure des SP français serait expliquée à la fois par des facteurs psychologiques et physiologiques. Au travers de quatre études expérimentales, les principaux résultats obtenus indiquent que l’entorse de la cheville est la blessure majeure dans cette population. Même si les missions des SP sont dangereuses et variées, les blessures surviennent paradoxalement au cours des heures de pratique de l’AP pendant les jours de garde. De plus, le nombre d’heures d’AP total pratiqué par semaine est associé aux blessures. Nous observons également que les performances réalisées au Y-balance test, au « weight bearing lunge test » sont prédictives de l’entorse de la cheville. Même si nos investigations permettent de mettre en évidence que la blessure est à la fois causée par des facteurs psychologiques (e.g., burnout) et physiologiques, la pratique de l’AP, obligatoire et nécessaire chez les SP, demeure paradoxalement le plus grand pourvoyeur d’accident de travail / Daily tasks of firefighters may induce significant musculoskeletal constraints, cardiovascular risks, burnout and injuries. The aim of this doctoral work was to characterize the specific injuries of French firefighters, and to analyze influence of physical activity (PA), burnout, coping strategies, personality traits, and achievement goal in this injury occurrence. We hypothesize that injuries of French firefighters would be explained by both psychological and physiological factors. Through four experimental studies, the main results indicate that ankle sprain is the major injury in this population. Although SP missions are dangerous and varied, paradoxically injuries occur during the hours of PA practice in day guard. In addition, the total number of hours AP practiced per week is associated with injury. We also observed that the performances achieved in the Y-balance test, the "weight bearing lunge test" are predictive of ankle sprains. Although our investigations have highlighted that the injury was caused by psychological (e.g., burnout) and physiological factors, practicing sessions of AP is compulsory and required in this job, and paradoxically remains the largest provider of occupational incident

In the restaurant industry, information gap between inside management and outside stakeholders could be considerable due to analyst’ lack of interest in the restaurant industry and restaurant firms’ high intangible asset and scant corporate payout. Given the possible seriousness of information asymmetry in the restaurant industry, the subject of information asymmetry could bear great importance in the restaurant industry. Nevertheless, information asymmetry has never been the subject of study in the restaurant industry, not to mention the hospitality industry generally. With this research gap in mind, this study conducted extensive research to understand the various implications of information asymmetry in the restaurant industry. The first objective of this study was to examine the magnitude of information asymmetry in the restaurant industry. This study demonstrated the seriousness of information asymmetry in the restaurant industry by showing that the size of information asymmetry within the restaurant industry is greater than that of other services industries (i.e., utility, REIT, and airline industries). The second objective of this study was to examine the unique determinants of information asymmetry in the restaurant industry. The results of this study showed that in the restaurant industry, information asymmetry widens as the size of accruals increases. Additionally, information asymmetry was found to be smaller for franchise restaurants than for non-franchise restaurants. The third objective of this study was to investigate the impact of information asymmetry on some managerial behaviors in the restaurant industry. This study showed that in the restaurant industry, information asymmetry leads to a manager’s reduced corporate payout and increased investment inefficiency. The last objective of this study was to examine the impact of information asymmetry on firm value in the restaurant industry. By demonstrating a curvilinear relationship between information asymmetry and firm value, this study showed that there exists not only a negative impact of information asymmetry but also a positive impact of information asymmetry on firm value in the restaurant industry. Furthermore, this study showed that the positive impact of information asymmetry on firm value is more prominent for high-leveraged and mature firms than their counterpart groups. This study’s results not only help understand the characteristics of information asymmetry in the restaurant industry but also introduce a new window for understanding managerial behaviors and firm value in the restaurant industry.

The determination of diatom species is mostly based on morphology of a silicified cell wall. It is complicated by the fact of cell diminution during the vegetative phase of the life cycle, which is conected with shape changes and loss of some taxonomically importat characters. Even though the diminution during the life cycle is generally known phenomeon, there is a lack of studies on this theme. In this masters thesis, four monoclonal populations of model pennate diatom strains were used in order to study shape dynamics during the life cycle. The strains were cultivated for almost three years and parts of the cultures with a different size stages were fixed in permanent preparations. The digital photographs of the cells were used as a material for the geometric morphometrics analyses. The study revealed high contribution of significant allometric changes to an overall shape variability. During the vegetative phase of the life cycle, disparity of the cells increases and complexity of the cells decreases. The contribution of symetric variability to an overall shape variability is more than eighty percent. Phenotypic plasticity in a monoclonal populations is an interesting finding from an evolutionary point of view. It may indicate constraints caused by the silica cell wall. During the size diminution...

This dissertation presents muon charge asymmetry, fiducial differential cross section and CMS single muon trigger efficiency measurements as a function of muon pseudorapidity for inclusive W→μν events produced in proton-proton collisions at the LHC. The data were recorded by the CMS detector at a center-of-mass energy of 8 TeV and correspond to an integrated luminosity of 18.8 fb-1. Several comparisons are performed to cross-check the experimental results. Muon efficiency measurements are compared to estimated values from Monte Carlo simulations and reference values recommended by CMS physics object groups. The differential cross section and the charge asymmetry measurements are compared to theoretical predictions based on next-to-leading order and next-to-next-to-leading order QCD calculations with different PDF models. Inputs from the charge asymmetry and the differential cross section measurements for the determination of the next generation of PDF sets are expected to bring different predictions closer together and aid in reducing PDF uncertainties. The impact of the charge asymmetry on PDFs has been investigated by putting the asymmetry results into a QCD analysis at next-to-leading order and next-to-next-leading order with inclusive deep-inelastic scattering data from HERA. Significant improvement of the accuracy on the valence-quark distributions is observed. This measurement is recommended for more accurate constraints in future PDF determinations. More precise measurements of PDFs will improve LHC predictions.

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This theses explores muscle activity during bow draw. The goal of his study is to evaluate whether muscle activity corresponds with increase in mechanical robusticity of the left humerus found in mezolithic osteological material. Muscle activity is measured by the means of surface electromyography. We measure activity of arm and back muscles. Activity was measured on m. deltoideus, m. infraspinatus, m. biceps brachii, m. triceps brachii and m. latissimus dorsi. Muscle activity was measured on 20 male archers, during bow draw of three wooden long-bows. Results of this study support the idea that change in robusticity of the left humerus could be caused by frequent bow use in post-glacial Europe.

The financial crisis in the USA is due to its great consequences still considered to be current topic. Its causes were discussed and analyzed by many researchers, but mostly from the financial point of view. This thesis takes different approach and identifies the role of the moral hazard in the pre-crisis period. Moral hazard is very often underestimated and for many people uninteresting factor. Therefor, the thesis is divided into four parts, which present the theoretical background of moral hazard and bring up the importance and constant presence of it in today's world. The main part of this work is last chapter, which analyzes moral hazard in the causes of the financial crisis. Moral hazard played key role in the pre-crisis period when it was present at all possible levels deforming the behavior of market players and causing the market failure. The deformation had mostly form of excessive risk-taking, unfavourable financial products and abuse of the information asymmetry. Very specific and dangerous kind of moral hazard is associated with the government interventions such as Greenspan doctrine or Too big to fail policy. It is because of its systematic character, when opposed to the moral hazard in the private sector is not required the presence of information asymmetry.