Dans cette thèse, différents aspects de la propagation de lumière en milieux hétérogènes sont abordés. Dans un premier temps, les concepts et les outils fondamentaux de la propagation des ondes en milieux désordonnés sont rappelés.Ensuite, le régime de localisation d'Anderson est abordé pour des systèmes bidimensionnels ouverts. La localisation est mise en évidence de manière simple à partir du calcul de la figure de speckle transmis par une réalisation unique du désordre et en faisant varier les conditions d'illumination. Les régimes localisé et diffusif sont alors nettement différenciés, permettant d'introduire un nouveau critère pour la localisation.Puis, un régime dilué dans lequel les corrélations du désordre jouent un rôle important est étudié. En particulier, l'étude se concentre sur les milieux hyperuniformes, qui permettent de montrer de manière spectaculaire comment les corrélations peuvent changer les propriétés de diffusion d'un milieu jusqu'à le rendre totalement transparent. L'influence des corrélations du désordre sur le coefficient d'absorption d'un milieu désordonné est également envisagée, elle s'avère être modérée.La dernière partie s'intéresse aux fluctuations du taux d'émission d'un émetteur de type molécule fluorescente enfoui dans un milieu désordonné en fonction de sa position. Cette corrélation spatiale d'un nouveau genre permet d'obtenir de manière découplée des informations sur les détails microscopiques du milieu (corrélations) et l'environnement local de la source. / In this thesis, different aspects of wave propagation in complex media are adressed. First, basicconcepts and tools of the propagation of waves in disordered media are reminded.Then, the Anderson localization regime is tackled for two-dimensional open systems. The localization is highlighted in a simple way from a calculation of the transmitted speckle pattern for a single configuration of the disorder with varying illumination conditions. Localized and diffused regimes are clearly differenciated, allowing to introduce a new critria for localization.Next, a weak scattering regime for which correlations of the disorder play a significant role is investigated. Namely, the study is focused on hyperuniform materials, where correlations are such that they are transparent compared with their uncorreleted equivalent. The influence of the correlations of the disorder on the absorption coefficient is also considered, but it is found to be moderated.The final part is dedicated to the fluctuations of the decay rate of an emitter, (e. g. fluorescentmolecule), embedded in a disordered medium as a function of its position. This new type of spatialcorrelation allows to extract information on the microscopic details of the medium (correlations) and the local environment of the source in an uncoupled way.

A estrutura e o comportamento de proteínas são de grande interesse a uma infinidade de áreas de conhecimento, com especial destaque para alimentação e saúde. As proteínas compõem uma fundamental classe de moléculas biológicas, com capacidade para interagir com diversas outras estruturas e formar complexos. Dois tópicos principais são abordados neste trabalho: (a) avaliação da formação de complexos entre três proteínas do soro do leite (-lactoalbumina, -lactoglobulina e lactoferrina) em diferentes condições experimentais de força iônica e pH da solução através de derivadas da energia livre e (b) avaliação de aspectos relacionados com a fundamentação teórica dos modelos moleculares com granularidade grossa e uso do dielétrico contínuo empregados para estudo do fenômeno da complexação molecular, através da análise, em larga escala, da correlação de cargas em proteínas disponíveis no banco de dados de proteínas. Os estudos teóricos de complexação foram realizados através do emprego de simulações Monte Carlo Metropolis, com o modelo do solvente contínuo, constante dielétrica homogênea e sal implicitamente descrito. Os estudos de complexação permitem compreender os mecanismos moleculares envolvidos, elucidando, inclusive, controvérsias experimentais e oferecendo orientação para aplicações. Já os resultados do estudo de correlação de cargas em estruturas experimentais de proteínas permitem justificar as aproximações do modelo. / The structure and behavior of proteins are of great interest for a number of science fields, with special emphasis to food industry and health. Proteins comprise a fundamental group of biological molecules, with the capacity of interacting with several other structures and creating complexes. Two major topics are covered in this study: (a) evaluation of complex formation among three whey proteins (-lactalbumin, -lactoglobulin and lactoferrin) under different experimental conditions of ionic strength and pH of solution through free energy derivatives and (b) evaluation of features related to the theoretical basis of the coarse-grained molecular models and the use of continuous dielectric which are employed to investigate the molecular complexation phenomenon, through analysis, on a large scale, of charge correlation in proteins available in the protein data bank. The theoretical studies of complexation were performed through the use of Monte Carlo Metropolis simulations, with continuous solvent model, homogeneous dielectric constant and salt implicitly described. The complexation studies allow to understand the molecular mechanisms involved, also elucidating experimental controversies and offering orientation to applications; whereas the results of the charge correlation study in experimental structure of proteins allow justify the approximations of the model.

Foi realizado um estudo com dados físicos em superfície provenientes de implementação do modelo numérico POM e dados de clorofila a do sensor MODIS, no Atlântico Sul e Tropical, tendo como finalidade analisar as variações espaciais de suas correlações. O modelo hidrodinâmico foi submetido a uma validação com dados do Projeto PIRATA e do sensor MODIS, obtendo-se resultados satisfatórios, principalmente em superfície. A clorofila a apresenta altos valores de correlação com variáveis físicas em superfície, porém esses valores são influenciados pela presença dos sinais anual e semianual nas séries temporais. Consequentemente, as análises foram desenvolvidas após a remoção desses sinais das séries. As correlações cruzadas entre as variáveis físicas e clorofila a tiveram valores altos em módulo apresentando, de maneira geral, padrão espacial característico de correlações negativas no interior do Giro Subtropical e positivas nas demais regiões para temperatura e salinidade em superfície e elevação do nível do mar. Esse padrão espacial é mais evidente para elevação e temperatura em superfície, apresentando defasagem no tempo de resposta biológica de quase zero no interior do Giro Subtropical e Equador, com predomínio de atrasos nessa resposta nas demais regiões. A covariância cruzada foi calculada para alguns pontos ao longo do meridiano de 20ºW, para elevação de superfície e temperatura, verificando-se concordância com os resultados obtidos pela correlação cruzada. A análise espectral dessa covariância salientou a ocorrência de alguns sinais, dentre eles os sinais com períodos de 3,5 e 0,7 anos (que provavelmente estão associados aos fenômenos ENSO) e o período de 0,33 anos (que pode estar relacionado a ressonâncias do sinal anual). A assinatura desses sinais apresentou variabilidade latitudinal. / A study was performed with physical data at the surface produced by the implementation of the numerical model POM and chlorophyll a data from the MODIS sensor, in the Tropical and South Atlantic, with the aim of to analyze the spatial variations of their correlations. The hydrodynamic model was subjected to a validation with data of Project PIRATE and MODIS sensor, obtaining satisfactory results, especially at the surface. The chlorophyll a values have high correlation with physical variables at the surface, but these values are influenced by the presence of annual and semiannual signals in the time series. Then, the analyses were carried out after removal of these signals from the series. The cross-correlations between physical variables and chlorophyll a had high magnitudes showing, in general, characteristic spatial pattern of negative correlations within the Subtropical Gyre and positive in other regions, for surface temperature and salinity and sea surface level. This spatial pattern is most evident in surface elevation and temperature, presenting lag in the biological response time nearly zero within the Subtropical Gyre and Equator, with a predominance of delays of the responses in other regions. The cross-covariance is calculated for several points along the meridian of 20º W for surface elevation and surface temperature, verifying agreement with the results obtained by the cross correlation. Spectral analysis of this covariance shows the occurrence of some signals, including signals with periods of 3.5 and 0.7 years (which are probably associated with ENSO phenomena) and the period of 0.33 years (that can be related to resonances of the annual signal). The signature of these signals showed latitudinal variability.

Lorsqu’un liquide est refroidit suffisamment vite, la cristallisation peut être évitée. On a alors un liquide surfondu dont le temps de relaxation augmente fortement quand la température diminue vers la température de transition vitreuse Tg. En-dessous de Tg, le systèmeest dans l’état vitreux. Il vieillit : son temps de relaxation augmente au cours du temps. L’existence d’une longueur de corrélation croissante associée au ralentissement de la dynamique des liquides surfondus (ou des verres) est une des grandes questions toujours ouvertes dans la physique de la transition vitreuse. Des arguments théoriques très généraux ont montré que la mesure de la susceptibilité alternative non linéaire d’ordre trois des liquides surfondus (ou des verres) donnait directement accès à la longueur de corrélation dynamique. Nous avons mis au point une expérience à haute sensibilité permettant d’accéder à deux susceptibilités diélectriques non linéaires d’ordre trois près de Tg. Nos résultats obtenus sur du glycrol surfondu sont quantitativement en très bon accord avec les prédictions théoriques. Ils montrent que la longueur de corrélation dynamique augmente lorsque T diminue vers Tg. En dessous de Tg, l’étude du vieillissement d’une des susceptibilités non linéaires nous a permis de mettre en évidence que la longueur de corrélation dynamique augmente au cours du temps. Ces résultats renforcent le scénario selon lequel la transition vitreuse serait liée à un point critique sous-jacent, ce qui expliquerait l’ubiquité du comportement vitreux dans la nature. / Upon fast enough cooling, a liquid avoids crystallization and enters in a supercooled state. The relaxation time of this supercooled liquid increases extremely fast when the temperature decreases towards the glass transition temperature Tg. Below Tg, the system is in the glassy state. It ages : the relaxation time increases with time. The existence of a growing correlation length associated to the slowing down of supercooled liquids (or of glasses) is one of the main open issues in the physics of the glass transition. On very general theoretical arguments, it has been shown that the third order a.c. nonlinear susceptibility around Tg gives direct access to the dynamical correlation length. We have developped a high sensibility experiment to measure, close to Tg, two nonlinear dielectric susceptibilities of the third order. Our results performed on supercooled glycerol are quantitatively in very good agreement with theoretical predictions. They show that the dynamical correlation length increases when T decreases towards Tg. Below Tg, aging experiments of one of the nonlinear susceptibilities reveal that the dynamical correlation length increases with time. These results clearly evidence the collective character of glassy dynamics and reinforce the picture of an underlying critical point, which would explain the ubiquity of the glass transition in Nature.

Ce travail porte sur l'étude de la cohérence entre champs triplets générés par interaction non linéaire d'ordre trois. Un protocole indirect, basé sur l'étude du champ issu de la somme de fréquences des champs triplets dans un cristal non linéaire a été envisagé. Une modélisation théorique en formalisme quantique de l'évolution des champs, de leur génération à leur recombinaison, a été développée, donnant lieu à une recherche exhaustive des signatures de corrélations susceptibles d'émerger de notre protocole. Les expériences menées, à savoir la génération non linéaire bi-stimulée et la recombinaison des champs ainsi générés, sont en accord avec notre modèle théorique et permettent de mettre en évidence le masquage des corrélations entre les champs dans ce régime fortement injecté, ces corrélations étant contenues dans les fluctuations quantiques, alors négligeables, des opérateurs champs. Le calcul théorique prédit une signature de corrélations fortes entre les photons triplets dans la cas d'un génération par fluorescence paramétrique, et plus faible dans le cas d'une génération mono-stimulée. / This work deals about the study of coherence between triple photon beams generated by a third order non linear interaction. A protocol, based on the study of the field arising from sum-frequency of the triplet fields in a non linear crystal, was proposed. A theoretical model, in the quantum formalism, was developed, leading to an exhaustive research of the potential signature of the correlations. All the possible schemes were studied : triple fields generation from parametric fluorescence or from stimulated interaction, and recombination of two or three of the triple fields. The experiments we led, i.e. the bi-stimulated non linear generation and the recombination of the so-born fields, agree with our theoretical model and put into light the correlations hiding in this highly stimulated regime, since these correlations lie in the quantum fluctuations of the fields operators. The theoretical calculations predicts a strong correlations signature when the fields are generated from parametric fluorescence, and a weaker one in the case of a generation mono-stimulated.

Ce travail de thèse s'inscrit dans le cadre du développement de la méthode de mélange de configurations multiparticules-multitrous visant à décrire les propriétés de structure des noyaux atomiques. Basée sur un double principe variationnel, cette approche permet de déterminer simultanément les coefficients d'expansion de la fonction d'onde et les orbitales individuelles.Dans ce manuscrit, le formalisme complet méthode de mélange de configurations multiparticules-multitrous auto-cohérente est pour la première fois appliqué à la description de quelques noyaux des couches p et sd, avec l'interaction de Gogny D1S.Un première étude du 12C est effectuée afin de tester et comparer le double processus de convergence lorsque différents types de critères sont appliqués pour sélectionner les configurations à N-corps inclues dans la fonction d'onde du noyau. Une analyse détaillée de l'effet induit par l'optimisation des orbitales est conduite. En particulier, son impact sur la densité à un corps et sur la fragmentation de la fonction d'onde de l'état fondamental, est analysé.Une étude systématique de noyaux de la couche sd est ensuite conduite. Une analyse précise du contenu en corrélation de l'état fondamental est effectuée, et quelques quantités observables telles que les énergies de liaison et de séparation, ainsi que les rayons de charge, sont calculées et comparées à l'expérience. Les résultats obtenus sont satisfaisants. La spectroscopie de basse énergie est ensuite étudiée. Les énergies d'excitation théoriques sont en très bon accord avec les données expérimentales, et les caractéristiques dipolaires magnétiques sont également satisfaisantes. Les propriétés quadripolaires électriques, et en particulier les probabilités de transition B(E2), sont par contre largement sous-estimée par rapport aux valeurs expérimentales, et révèle un manque important de collectivité dans la fonction d'onde, dû à l'espace de valence restreint considéré. Si la renormalisation des orbitales induit une importante fragmentation de la fonction d'onde de l'état fondamental, seul un effet très faible est obtenu sur les probabilités de transition B(E2). Une tentative d'explication est donnée.Enfin, les informations de structure fournies par la méthode de mélange de configurations multiparticules-multitrous sont utilisées comme ingrédient de base pour des calculs de réactions telles que la diffusion inélastique de protons et d'électrons sur noyaux de la couche sd. Si les résultats révèlent aussi un manque de collectivité, les tendances expérimentales sont bien reproduites et sont améliorées par l'optimisation des orbitales. / This thesis project takes part in the development of the multiparticle-multihole configuration mixing method aiming to describe the structure of atomic nuclei. Based on a double variational principle, this approach allows to determine the expansion coefficients of the wave function and the single-particle states at the same time. In this work we apply for the first time the fully self-consistent formalism of the mp-mh method to the description of a few p- and sd-shell nuclei, using the D1S Gogny interaction.A first study of the 12C nucleus is performed in order to test the doubly iterative convergence procedure when different types of truncation criteria are applied to select the many-body configurations included in the wave-function. A detailed analysis of the effect caused by the orbital optimization is conducted. In particular, its impact on the one-body density and on the fragmentation of the ground state wave function is analyzed.A systematic study of sd-shell nuclei is then performed. A careful analysis of the correlation content of the ground state is first conducted and observables quantities such as binding and separation energies, as well as charge radii are calculated and compared to experimental data. Satisfactory results are found. Spectroscopic properties are also studied. Excitation energies of low-lying states are found in very good agreement with experiment, and the study of magnetic dipole features are also satisfactory. Calculation of electric quadrupole properties, and in particular transition probabilities B(E2), however reveal a clear lack of collectivity of the wave function, due to the reduced valence space used to select the many-body configurations. Although the renormalization of orbitals leads to an important fragmentation of the ground state wave function, only little effect is observed on B(E2) probabilities. A tentative explanation is given.Finally, the structure description of nuclei provided by the multiparticle-multihole configuration mixing method is utilized to study reaction mechanisms such as electron and proton inelastic scattering on sd-shell nuclei. Although the results also suffer from the lack of collectivity, the experimental trends are well reproduced and improved by the orbital optimization.

Os objetivos deste trabalho foram estimar as associações genéticas entre características de crescimento e produção de leite, utilizando análises bicaracterísticas, e entre características de crescimento, perímetro escrotal e idade ao primeiro parto utilizando modelos de regressão aleatória, de animais da raça Guzerá. Para as análises bicaracterísticas foram utilizadas 252.257 informações de pesos de machos e fêmeas aos 120 dias (P120), ao desmame (PD), ao ano (P365), ao sobreano (PSOBRE) aos 24 meses de idade (P24) e 6.493 lactações encerradas (P305), pertencentes a 4.723 vacas, e os modelos incluíram como os efeitos aleatórios o genético aditivo direto, de ambiente permanente materno e residual, e como efeitos fixos os grupos de contemporâneos e a idade da vaca ao parto (efeito linear e quadrático). Para as análises com os modelos de regressão aleatória foram utilizadas 159.366 observações de pesos e 23.780 de perímetro escrotal, realizadas entre 335 e 724 dias de idade dos animais e agrupadas em classes com intervalo de 10 dias, e 63.596 observações de idade ao primeiro parto. Os efeitos aleatórios considerados foram o genético aditivo direto, de ambiente permanente e residual e como efeitos fixos os grupos de contemporâneos, a idade da vaca ao parto (efeito linear e quadrático) e a curva fixa para modelar a tendência média da população (quadrática) sobre as classes de idade. Foram testados quatro possíveis graus de polinômios de Legendre (zero, linear, quadrático e cúbico), sendo o quadrático mais adequado para descrever as variâncias das características analisadas. Para verificar a existência de diferentes padrões de crescimento e agrupar os touros com base nos seus valores genéticos para produção de carne, leite e duplo propósito, foram realizadas análises de componentes principais e de agrupamento. As herdabilidades estimadas foram 0,23; 0,14; 0,16; 0,17; 021 e 0,22 para P305, P120, PD, P365, PSOBRE e P24, respectivamente, sugerindo que para as características de pesos, as herdabilidades aumentam com o aumento da idade dos animais. Mesma tendência foi observada pelas análises de regressão aleatória, cujas herdabilidades variaram de 0,17 a 0,31. As correlações genéticas entre os pesos em diferentes idades e a produção de leite foram positivas e de magnitude moderada a baixa, variando de 0,27 a 0,38 sugerindo que a seleção para peso e P305 possa ser realizada de forma simultânea nos mesmos animais. As análises de componentes principais indicaram a mesma tendência observada pelas correlações genéticas. As análises de agrupamento mostraram que a raça Guzerá possui touros com diferentes perfis genéticos, sendo possível realizar a seleção para corte, leite ou duplo propósito. As correlações genéticas entre os pesos e perímetro escrotal foram positivas e favoráveis, variando de 0,31 a 0,47, indicando que a seleção para aumento do peso poderá resultar em animais com maior perímetro escrotal. As correlações entre peso e idade ao primeiro parto variaram de -0,56 a -0,38 e perímetro escrotal e idade ao primeiro parto variaram de -0,55 a 0,08, sugerindo que a redução da idade ao primeiro parto poderá ocorrer, a longo prazo, quando peso e perímetro escrotal forem objetivos de seleção. A eficiência relativa de seleção indicou maior resposta pela seleção indireta para idade ao primeiro parto, quando realizada a seleção para perímetro escrotal a partir dos 615 dias de idade, quando comparada com o ganho genético direto para idade ao primeiro parto. / The objectives of this study were to estimate the genetic associations between growth and milk production traits in Guzerat cattle using two-trait analysis and between growth traits, scrotal circumference and age at first calving using random regression models. For two-trait analysis, 252,257 weight records of males and females obtained at 120 days of age (W120), weaning (WW), yearling (YW), post-weaning (PWW) and 24 months of age (W24), as well as 6,493 complete lactation records (W305) of 4,723 cows, were used. The models included direct additive genetic, maternal permanent environmental and residual effects as random effects, and the contemporary groups and age of cow at calving (linear and quadratic effect) as fixed effects. For the random regression models, 159,366 observations of weight and 23,780 observations of scrotal circumference, obtained at 335 and 724 days of age of the animals and divided into classes at 10-day intervals, as well as 63,596 observations of age at first calving, were used. Random direct additive genetic, permanent environmental and residual effects and the fixed effects of contemporary group and age of cow at calving (linear and quadratic effect) were considered. A fixed curve was used to model the average trend of the population (quadratic) on the age classes. Four possible degrees of Legendre polynomials (zero, linear, quadratic and cubic) were tested and the quadratic polynomial was the most appropriate to describe the variances in the traits analyzed. Principal component and cluster analyses were performed to determine the existence of different growth patterns and to group bulls based on their breeding values for meat, milk and dual-purpose production. The estimated heritabilities were 0.23, 0.14, 0.16, 0.17, 0.21 and 0.22 for W305, W120, WW, YW, PWW and W24, respectively, suggesting that, for the growth traits, heritabilities increased with increasing age of the animals. The same trend was observed when random regression analysis was performed, with heritabilities ranging from 0.17 to 0.31. The genetic correlations between weights at different ages and milk yield were positive and of moderate to low magnitude, ranging from 0.27 to 0.38. These estimates suggest that selection for weight and W305 can be performed simultaneously in the same animals. Principal component analysis indicated the same trend as observed by the genetic correlations. Cluster analysis showed the presence of bulls with different genetic profiles in the Guzerat breed, thus permitting selection for meat, milk or dual purpose. The genetic correlations between weights and scrotal circumference were positive and favorable (0.31 to 0.47), indicating that selection for increased weight will result in animals with greater scrotal circumference. The correlations between weights and age at first calving ranged from -0.56 to -0.38 and between scrotal circumference and age at first calving from -0.55 to 0.08, suggesting that the use of weight and scrotal circumference as selection objectives will result in the long-term reduction of age at first calving. The relative efficiency of selection indicated a greater response to indirect selection for age at first calving when selecting for scrotal circumference after 615 days of age, compared to the genetic gain obtained by direct selection for age at first calving.

Business process analysis and integration are key endeavours for today's enterprises. Recently, Web services have been widely adopted for the implementation and integration of business processes within and across enterprises. In this dissertation, we investigate the problem of enabling the analysis of service interactions, in today's enterprises, in the context of business process executions, and that of service integration. Our study shows that only fraction of interactions in the enterprise are supported by process-aware systems. However, enabling above-mentioned analyses requires: (i) a model of the underlying business process to be used as a reference for the analysis, and (ii) the ability to correlate events generated during service interactions into process instances. We refer to a process model and the corresponding process instances as a "process view". We propose the concept of process space to refer to all process related information sources in the enterprise, over which various process views are defined. We propose the design and development of a system called "process space discovery system" (PSDS) for discovering process views in a process space. We introduce novel approaches for the correlation of events into process instances, focusing on the public processes of Web services (business protocols), and also for the discovery of the business protocol models from the process instances of a process view. Analysis of service integration approaches shows that while standardisation in Web services simplifies the integration in the communication level, at the higher levels of abstractions (e.g., services interfaces and protocol models) services are still open to heterogeneities. We characterise the mismatches between service interfaces and protocol specifications and introduce "mismatch patterns" to represent them. A mismatch pattern also includes an adapter template that aims at the resolution of the captured mismatch. We also propose semi-automated approaches for identifying the mismatches between interface and protocol specifications of two services. The proposed approaches have been implemented in prototype tools, and experimentally validated on synthetic and real-world datasets. The discovered process views, using PSDS, can be used to perform various analyses in an enterprise, and the proposed adaptation approach facilitates the adoption of Web services in business process integration.

No description available.

The study of cultured neuronal networks has opened up avenues for understanding the ion channels, receptor molecules, and synaptic plasticity that may form the basis of learning and memory. The hippocampal neurons prepared from Wistar rats and put in culture, show, after a few days, spontaneous activity with typical electrophysiological pattern ranging from stochastic spiking to synchronized bursting. Using a multi-electrode array (MEA) having 64 electrodes, the electrophysiological signals are acquired, and connectivity maps are constructed using correlation matrix to understand how the neurons in a network communicate during the burst. The response of the neuronal system to epilepsy caused by induced glutamate injury and subsequent exposure of the system to phenobarbital to form different connectivity networks is analyzed in this study. The correlation matrix of the neuronal network before and after administering glutamate as well as after administering phenobarbital is used to understand the neuronal and network level changes that take place in the system. In order to interface a neuronal network to a physical world, the major computations to be performed are noise removal, pattern recovery, pattern matching and clustering. These computations are to be performed in real time. The system should be able to identify a pattern and relate a physical task to the pattern in about 200-400 ms. Algorithms have been developed for the implementation of a real-time neuronal system on a multi-node digital processor system.