Phagocytosis is the process by which cells engulf foreign bodies. It is the hallmark behavior of white blood cells, being the process through which those cells ingest and degrade pathogens and debris. To date a large amount of research has focused on documenting the existence and role of biochemical components involved with phagocytosis. Scores of signaling molecules have been implicated in the complex signal cascade which drives the process. These molecules are small (typically no larger than 5 nanometers) and operate in a crowded, chemically “noisy,” environment, yet they coordinate the cell's activity over comparatively expansive distances (as large as 20 micrometers). How these molecular processes scale-up to coordinate the activities of the cell over such massive distances is largely unknown. Using a planar analog of phagocytosis termed “frustrated phagocytosis,” we experimentally demonstrate that phagocytosis occurs in three distinct phases: initial cell-antigen binding, symmetric spreading, and late-stage contraction. Initial binding and symmetric spreading appears to be both mechanically and chemically similar to the quasi-universal cellular behaviors of adhesion and migration. Adhesion and migration have received extensive attention from the biophysics community in recent years. Leveraging these similarities, we adapt the biomechanical frameworks used in models of migration to phagocytosis. We show that macroscopic properties such as a cell's effective viscosity and membrane cortical tension can be used to model cell behavior during phagocytosis. Our experiments reveal that late-stage contraction distinguishes frustrated phagocytosis from other spreading behaviors. This contraction is myosin dependent. Additionally we demonstrate, for the first time, that late-stage contraction corresponds with formation of a contractile F-actin belt. Based on the dynamic contraction model (DC) developed to explain actin structure during cell migration we propose a DC model of phagocytosis which posits that contractile belt formation is the result of a late-stage myosin activity coupled with F-actin.

Les deux principaux traités de chasse français médiévaux, le Livre du roy Modus et de la royne Ratio, rédigé entre 1354 et 1377 par un seigneur normand, Henri de Ferrières et le Livre de chasse, écrit de 1387 à 1388 par le comte Gaston III de Foix-Béarn, dit Febus, sont nés de la volonté d’établir une somme des savoirs cynégétiques et de les transmettre aux générations futures grâce à un livre associant des images au texte. Ce travail se propose de mettre en lumière les modalités de la création iconographique, la fonction des miniatures, leur relation avec le texte, au sein d’un ouvrage didactique profane, ainsi que la transmission d’un modèle, en se fondant sur les exemplaires les plus anciens de chaque œuvre (exécutés en 1379 et 1388-1390) et sur un corpus représentatif de leurs suiveurs, s’échelonnant sur un siècle. On a pu expliquer l’apparition d’un tel projet à la fin du XIVe siècle en analysant le propos et les intentions des auteurs et en cernant un contexte intellectuel, social et artistique favorable. L’examen des données formelles des livres et surtout de leur mise en page a montré un équilibre entre texte et image et le caractère pédagogique de leur traitement visuel. L’étude approfondie des cycles originaux a révélé la souplesse des mises en scène et des procédés narratifs s’adaptant aux contenus variés, l’implication concomitante de l’auteur et de l’artiste dans la création des illustrations, la variété des usages faits par les miniatures du référent textuel et la multiplicité des rôles dévolus aux images. Les premiers traités de chasse enluminés voient le langage pictural collaborer avec le langage écrit au service de l’ambition didactique du livre. / The two principle French medieval huntbooks, the Livre du roy Modus et de la royne Ratio, written between 1354 and 1377 by Henri de Ferrières, a Norman nobleman, and the Livre de chasse, written between 1387 and 1388 by Comte Gaston III de Foix-Béarn, called Febus, were encouraged and sponsored for the purpose of establishing a significant compilation of hunting knowledge, intended for future generation through a work associating illustration with the text. The present thesis proposes a clarification of the modes of iconographic creation, the role of miniatures, their relation to a text, at the heart of secular didactic works, as well as transmitting a model, founded upon the oldest copies of each work (executed respectively in 1379 and 1388-1390) and on a representative body of works by followers extended over one century. It was possible to explain the appearence of such a project at the end of 14th century by analysing proposals and intentions of the authors and discerning favorable intellectual, social and artistic context. Examination of book content and espacially setting on the page showed balance between text and ilustration and the pedagogic character of visual treatment. Extended study of original cycles revealed the suppleness of the visual story line and of the narrative process adapting to variable content, the concomitant connection between author and artist for the creation of illustrations, the variety of textual usages in miniatures and the multiplicity of roles given to images. The first illuminated huntbook treatises show pictural language working effectively with written language in the service of didactic purposes of the book.

This work introduces a method for optimal combination of light paths generated from the camera and from the light sources in the Photon Mapping algorithm used for computing global illumination. Our method is based on Multiple Importance Sampling, a general approach, introduced by Veach, for adaptive path connection in Bidirectional Path-Tracing. Our goal is to examine this method in connection with the biased algorithm of Photon Mapping and to improve the ineffective heuristic used in the original version of this algorithm. This heuristic is usually problematic when applied to the scenes where highly glossy materials prevail.

La microscopie à éclairements structurés (SIM) permet théoriquement de doubler la résolution d’un microscope optique standard. Pour atteindre cette limite théorique, le SIM requière un contrôle très précis des illuminations, ce qui le rend coûteux et difficile à calibrer. Cette thèse cherche à simplifier drastiquement le principe du SIM en proposant une approche « aveugle » qui reconstruit une image de l’échantillon à partir d’éclairements aléatoires, i.e., très facile à générer. Cette stratégie permet en théorie l’imagerie super-résolue tout en réduisant fortement le coût de l’instrument. Nous avons étudié du point de vu théorique et algorithmique les performances et les limitations d’un estimateur joint de l’objet et des illuminations (estimateur Blind-SIM joint). Notamment, une reformulation mathématique du problème d’estimation jointe a été proposée qui permet d’analyser l'origine de la super-résolution mais également de proposer des nouvelles stratégies de mises en œuvre très rapides. Une étude empirique a mis en lumière l’impact de la parcimonie et du contenue fréquentielles des illuminations sur le niveau de super-résolution obtenu. L’estimateur joint étant asymptotiquement inconsistant, nous nous sommes également intéressé à définir un « critère de contraste » pour ce problème permettant d’estimer uniquement l’objet d’intérêt. Une étude mathématique de la capacité de super-résolution de ce type d'estimateur a été conduite. Enfin, on a observé un effet de super-résolution en condition réelles sur de nombreux objets, 2 ou 3D, fixe ou mobile, biologique ou non tel que des billes, des podosomes, de l’actine. / Structured illumination microscopy (SIM) allow theoretically to double the super-resolution of a standard optical microscope. However, to reach this theoretical limit, SIM require a precise knowledge of the illuminations, making it costly and difficult to calibrate. The aim of this thesis is to simplify the use of SIM by using a blind approach who allow the use of random illuminations to reconstruct a super-resolved image of the object. This strategy theoretically allow the super-resolution, while maintaining a low cost instrumentation. During those three years of thesis, we have studied theoretically and algorithmically the performances and the limitations of a joint estimator of the objet and the illuminations (joint Blind-SIM estimator). A mathematically equivalent reformulation of the joint problem was proposed allowing us to study the super-resolution origin and to propose a fast and parallelizable new approach. An empirical study has highlighted the impact of parsimony and of the frequency content of the illuminations on the reached super-resolution level. Because the joint estimator is asymptotically not consistent, we also studied a contrast criterion for our problem (typically a marginal likelihood), here only the object of interest is estimated. We have mathematically studied the super-resolution capacity of this kind of estimators. Finally, real data using random illuminations where acquired and we have observed a super-resolution effect using our algorithms on multiples real objects of different kind, 2 or 3D, fix or mobile, biological or not, like beads, podosomes, actines.

A importância da compreensão da questão energética nos edifícios, com enfoque nos fenômenos energéticos pelos quais o vidro participa e o delineamento de uma aproximação de desempenho em energia e conforto de vidros recobertos com filme eletrocrômico de Nb2O5, formam a finalidade deste trabalho. Os invisíveis fenômenos energéticos em superfícies envidraçadas promovem descontrole de ambos iluminação e climatização de ambientes, associando janelas a impacto energético, cujas consequências tem causado desenvolvimento de especificações, normatização e legislação. A origem deste desequilíbrio nasce da desatenção dos projetistas (e da maioria dos homens), que deixam de observar o céu. O sol envia a Terra diariamente dez mil vezes mais energia que o consumo mundial. Tamanha intensidade disponível no meio ambiente, deparando-se com superfícies que permitem sua entrada em ambientes internos. Este trabalho integra conceitos básicos de energia,sol, conforto e comportamento térmico e óptico de parte dos materiais vítreos de mercados atual e futuro, com a pretensão de apresentar-se como orientação primária aos profissionais do ramo. Paralelamente obteve-se a curva de transmissão solar de filme eletrocrômico de Nb2O5 obtido via sol-gel sonocatalítico. Este processo foi desenvolvido por grupo de pesquisa desta universidade. Busca-se então associar os resultados obtidos com os conceitos apresentados, indicando efeitos a respeito de sua aplicação na arquitetura como vidro e protetor solar. / The aim of this work proposes an understanding about the energy impact promoted by buildings, focalizing the energetic phenomenon involving glazing bulks and indicating an energetic and comfort behavior of glasses recovered with Nb2O5 film. The energetic transfer through glasses promotes decontrol of environment illumination and temperature, associating windows to energetic impact, whose consequences have caused the development of specifications, standardization and legislation. The source of this energetic instability arises from designers inattention (also majority men), who forget to observe the sky. The Sun sends to Earth daily ten thousand times more energy than world consume. When such energy reaches surfaces that permit its entrance and hinder its exit, indoors illumination and heating are caused. This work groups basic concepts of energy, sun, comfort and thermal-optical behavior of glass materiaIs in nowadays and future markets, pretending offer a primary orientation to professional in this field. Allied to this, were obtained the solar transmission curves of the electrochromic film of Nb2O5, produced by Sol-Gel sonocatalytic process. Such process was developed by research group from this university. The results were associated with the concepts presented, indicating effects about its application as glass and solar protector in architecture.

A agricultura de precisão fundamenta-se na investigação e manejo da variabilidade dos atributos de interesse agrícola. Diversos fatores que condicionam a produtividade da lavoura, como fertilidade do solo, compactação, condutividade elétrica, já foram alvos de diversos estudos e os resultados tem sido bastante encorajadores. No entanto muitas vezes não existe uma correlação direta entre esses fatores e a produtividade expressa em mapas digitais gerados após a colheita. O objetivo desse estudo foi desenvolver uma tecnologia para mapeamento de iluminação e determinação de áreas de sombreamento, através do software SPRING e de softwares de apoio. A metodologia se mostrou de baixo custo e de relativa facilidade de implementação, podendo servir de uma boa ferramenta para o planejamento de culturas e investigação da variabilidade agrícola. / Precision agriculture is based on investigation and management of the variables within the interests of agriculture. Diverse factors effect the crop productivity of like soil fertility, compaction, electric conductivity, were already targets for various studies and the results have been encouraging. However, many times there is no direct correlation between those factors and the productivity expressed in digital maps generated after the harvest. The object of this study was to develop the technology for mapping the areas of lighting and shadow by using the software SPRING and other support software. The methodology was shown to be of little cost and relative ease of implementation, serving as a good tool for the planning of cultures and investigation of agricultural variability

Submitted by William Justo Figueiro (williamjf) on 2015-06-25T22:57:04Z No. of bitstreams: 1 37.pdf: 3114902 bytes, checksum: 4bb3e86045ed3d7de9871884757e4501 (MD5) / Made available in DSpace on 2015-06-25T22:57:04Z (GMT). No. of bitstreams: 1 37.pdf: 3114902 bytes, checksum: 4bb3e86045ed3d7de9871884757e4501 (MD5) Previous issue date: 2014 / Nenhuma / Contemporaneamente, com as cidades se tornando cada vez mais verticais, é difícil projetar espaços urbanos em que a iluminação e o calor do sol consigam atingir o solo e os andares inferiores dos prédios urbanos de maneira a não prejudicar a saúde da população. Diante das limitações físicas para a análise do grau de iluminação natural de um grande conjunto de prédios torna-se necessária a simulação através de modelos computacionais. Parâmetros como a localização geográfica, altura, número e distância entre os prédios são usados para a identificação dos níveis de radiação solar e os consequentes desafios ambientais e tecnológicos a serem superados visando a sustentabilidade. O objetivo deste trabalho é analisar o grau de iluminação natural externa em áreas urbanas para que se possa buscar uma solução técnica a fim de propiciar ao homem as condições prediais adequadas de iluminação e temperatura. Para tanto, é apresentado um modelo de iluminação de prédios que contempla simulações que permitem tanto a análise do grau de iluminação por prédio quanto a análise do grau de iluminação global em um grande conjunto de prédios em função do parâmetro através da técnica de PCA. / Contemporaneously, cities are becoming more vertical, it is difficult to design urban spaces in which light and heat from the sun would attain the ground and lower floors of urban buildings in a way that does not harm the health of the population. Given the physical limitations to the analysis of the degree of natural lighting of a large number of buildings, it is necessary to simulate it by computer modeling. Parameters such as geographical location, height, number and distance between buildings are used to identify levels of solar radiation and the resulting environmental and technological challenges to be overcome for the sustainability. The objective of this work is to analyze the degree of outside natural lighting in urban areas to seek a technical solution in order to provide the suitable human conditions of lighting and temperature. For this, a model lighting of buildings that includes simulations that allow both the analysis of the degree of illumination building as the analysis of the degree of global illumination on a large set of buildings is presented. The result is presented using the technique of PCA.

Actif de ca. 1420 à ca. 1450-1460, le Maître de la « Légende dorée » de Munich est, comme le Maître de Dunois, une personnalité issue de l'atelier de Bedford. Miniaturiste ayant surtout exercé à Paris, son œuvre témoigne aussi d'ancrages provinciaux, normands et ligériens notamment. Ce travail s'appuie sur un catalogue de 48 manuscrits, dont 41 livres d'heures. L'étude vise à dégager des spécificités iconographiques et stylistiques du Maître. Parmi les premières se notent l'intérêt marqué pour l'ornementation et le souci du détail, ainsi des auréoles ouvragées, voûtes aux nervures festonnées, livres et meubles. Trait iconographique saillant de l'œuvre tant par sa fréquence que par sa nouveauté, les épis de blé aux crèches font l'objet d'une étude attentive, du fait du sens dont ils sont porteurs et du possible lien entre ce motif et la spiritualité contemporaine, notamment la Dévotion Moderne. Stylistiquement, le Maître de la « Légende dorée » de Munich se caractérise par des lèvres aux commissures tombantes, des arcades sourcilières marquées au trait, dont il use aussi abondamment pour souligner carnations et contours d'objets, et par une palette riche et contrastée. Calendriers et décors marginaux ont également servi à des rapprochements pour aboutir à des regroupements chronologiques au sein du corpus. Inspiré, directement ou via des modèles puisés au sein de l'atelier Bedford, par les Limbourg, le Maître d'Egerton et la peinture septentrionale, le Maître de la « Légende dorée » de Munich a collaboré, comme maître d’œuvre ou peintre de quelques miniatures, avec d'autres artistes, documentés ou non. Il a pu travailler pour des commanditaires aussi bien anglais que français. / As the Dunois Master, the Munich « Golden Legend » Master, fl. from ca. 1420 to ca. 1450-1460, is one artistic figure originating from the Bedford workshop. This miniaturist was active mostly in Paris, but his work also shows connections with provinces like Normandy and the Loire valley. This paper is based on a 48-manuscript catalogue, among which are 41 books of hours. The study aims at bringing out the iconographic and stylistic Master's salient features. Among the first, one notes a deep interest in details and ornaments, which is to be found in finely wrought haloes, vaults with festooned ribs, books and furniture. Within the corpus, ears of wheat in cribs are noteworthy due to both their frequency and novelty. They are subject to deep insight due to the meaning they bear, and to the possible relationship between this motif and the contemporary spirituality, especially the Modern Devotion. Stylistically, typical of the Munich « Golden Legend » Master are falling lip-corners, eyebrow arches marked with line, which he also largely uses to underline flesh tones and object outlines. His range of colours is varied and full of contrasts. Calendars and marginal decoration have also been used to compare manuscripts, in order to build chronological groupings within the corpus. The Munich « Golden Legend » Master has been, either directly or via models available inside the Bedford workshop, influenced by the Limbourgs, the Egerton Master and northern painting. He cooperated, being the chief illuminator or simply helping by painting a few miniatures, with other artists, whether documented or not, and may have worked for both English and French patrons.

Este trabalho apresenta uma metodologia para inspeção de lentes oftalmológicas orgânicas esféricas durante seu processo de polimento. A metodologia consiste na obtenção de uma imagem em uma câmera de vídeo CCD, usando-se luz ultravioleta, da lente a ser inspecionada, e posterior processamento desta imagem para discriminar a presença de riscos de outros artefatos que poderão aparecer na imagem capturada. Para a detecção da presença de riscos foram utilizados os descritores de Fourier. Atenção especial foi dada à iluminação da lente, que é fator determinante na obtenção de uma boa qualidade de imagem. Os resultados mostram a eficiência do método e permitem sua utilização durante o processo de fabricação de lentes. / This work presents a methodology for inspection of spherical organic ophthalmic lenses during the polishing process. The methodology encompasses the capture of an ultraviolet image of the lens under inspection by a CCD video camera and associated processing of the image to discriminate between scratches on the lens and artifacts that can appear on the image. Fourier descriptors were used to detect the existence of scratches. Special attention was given to illumination which is a determining factor in grabbing an image with good quality. The results show that the method is efficient and that it can be used in the lens manufacturing process.

Ce travail de thèse concerne l'amélioration du pouvoir de résolution de la microscopie optique en champ lointain. Nous avons développé des techniques qui tirent profit de la relation liant le champ électromagnétique émis par un objet à l’éclairement utilisé. En utilisant plusieurs images obtenues pour différents éclairements, et à l’aide d’un algorithme d'inversion approprié, il est possible d'accéder à des fréquences spatiales de l'objet habituellement filtrées par le microscope.Ce concept est d’abord appliqué à une technique de microscopie cohérente : la tomographique optique de diffraction. Elle permet d’obtenir numériquement une carte quantitative de la permittivité diélectrique de l'objet, avec une résolution supérieure à celle d'un microscope classique, à partir de plusieurs hologrammes de l'échantillon. Dans ce cadre, nous montrons que le phénomène de diffusion multiple permet d’atteindre des résolutions encore plus spectaculaires s’il est pris en compte. Nous étudions ensuite la microscopie de fluorescence par éclairement structuré, que nous proposons d’améliorer de deux manières différentes. Dans la première, nous utilisons un algorithme d’inversion capable de retrouver simultanément la densité de fluorescence et les éclairements utilisés. Grâce à celui-ci, nous pouvons remplacer l’illumination périodique et contrôlée généralement utilisée, par des speckles aléatoires formés avec un montage remarquablement simple. Nous montrons expérimentalement l'efficacité de cette approche. Dans un second temps, nous proposons de remplacer la lamelle de verre sur laquelle est repose l’échantillon par un réseau diélectrique nanométrique. Celui-ci crée à sa surface une grille de lumière de période inférieure à la limite de diffraction, ce qui permet d’améliorer d’avantage la résolution finale de l’image reconstruite. Nous détaillons la conception, la fabrication et la caractérisation expérimentale de ce substrat nanostructuré. / This PhD work focuses on the resolution improvement of far-field optical microscopy. We have studied and developed different techniques that take advantage of the relationship between the sample, the illumination and the diffracted (or emitted) field, in order to increase final band-pass of the image beyond that imposed by the diffraction phenomenon. In In these approaches, several images of the same sample are recorded under different illuminations. An inversion algorithm in then used to reconstruct a super-resolved map of the sample from the set of measurements.This concept is first applied to coherent microscopy. In tomographic diffraction microscopy, many holograms of the same unstained sample are obtained under various incidences, then used to numerically reconstruct a quantitative map of permittivity of the sample. The resolution is usually better than that of classical wide-field microscopy. We show theoretically and experimentally that, far from being a drawback, the presence of multiple scattering within the sample can, if properly accounted for, lead a to an even better resolution.We then study structured illumination fluorescence microscopy. We present two different ways for improving this method. The first one takes advantage of an inversion algorithm, which is able to retrieve the fluorescence density without knowing the illumination patterns. This algorithm permits one to replace the periodic light pattern classically used in structured illumination microscopy by unknown random speckle patterns. The implementation of the technique is thus considerably simplified while the resolution improvement remains. In the second approach, we propose to replace the coverslip on which the sample usually lays, by a sub-lambda grating. The latter is used to form, in near field, a light grid with sub-diffraction period that is able to probe the finest details of the sample. The design, fabrication and optical characterization of this key structure are detailed.