Orientador: Marlies Sazima / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-21T12:52:20Z (GMT). No. of bitstreams: 1 Amorim_FelipeWanderley_D.pdf: 21680900 bytes, checksum: d3888d6cbcafe24a20fcecee1b94e4fb (MD5) Previous issue date: 2012 / Resumo: Polinização por esfingídeos é provavelmente um dos sistemas menos estudados em comunidades tropicais, especialmente na Mata Atlântica, que constitui um dos biomas mais diversos e ameaçados do planeta. Foram estudadas a flora esfingófila e a fauna de Sphingidae em uma área de Floresta Ombrófila Densa Montana (FODM) e analisados os processos ecológicos subjacentes às interações entre esfingídeos e plantas. Ao todo 24 espécies compuseram a flora esfingófila da área estudada, dentre as quais, quatro espécies possuem adaptações estritas à polinização por esfingídeos. A fauna de esfingídeos foi composta por 50 espécies com grande predomínio de mariposas com probóscides curtas. Plantas e esfingídeos apresentaram ajustamento morfológico significativo na distribuição dos comprimentos de tubos florais e de probóscides, porém ao contrário do padrão geral de outras áreas na região Neotropical, não houve ajustamento fenológico estrito entre esfingídeos e plantas na Mata Atlântica. A presença sazonal de mariposas com longas probóscides na área está relacionada principalmente a emigração de espécies oriundas de ecossistemas adjacentes à FODM. Limitação de polinizadores foi comum nas espécies vegetais mais especializadas o que limitou a produção de frutos. Os processos de seleção mediada por polinizadores nestas espécies, também foram afetados. Porém, processos locais de seleção mediada por polinizadores, provavelmente devem agir na estruturação de ajustamentos morfológicos entre esfingídeos e plantas, mesmo sendo variáveis no tempo e no espaço, conforme sugerem os resultados. Apesar da ausência de ajustamento fenológico estrito entre esfingídeos e plantas na Mata Atlântica, o padrão geral registrado em outros biomas sugere ocorrência de esfingídeos de longas probóscides coincidente com a floração de espécies esfingófilas com longos tubos florais. Como este grupo de plantas oferece maior quantidade de néctar em um "nicho privado" aos esfingídeos de longas probóscides, esse ajustamento fenológico poderia ser visto como estratégia para minimizar a competição por recursos florais entre mariposas com probóscides longas e curtas nas comunidades de Sphingidae / Abstract: Hawkmoth pollination is probably one of the least studied pollination systems in tropical communities, particularly in the Atlantic Rainforest, one of the most diverse and threatened biomes in the world. In this work we studied the sphingophilous plants and the Sphingidae fauna in an area of Highland AtlanticRainforest (HARF) and analyzed the ecological processes underlying the interactions between plants and hawkmoths. Altogether, 24 species composed the sphingophilous flora recorded to the study site, among which four species had strict adaptations related to hawkmoth pollination. The hawkmoth fauna was composed of 50 species with great predominance of short-tongued moths. Hawkmoths and plants showed a significant morphological match in the distribution of floral tubes and proboscises lengths, but unlike the general pattern obtained for other areas in the Neotropical region, we did not record a strict phenological match between hawkmoths and plants in the Atlantic Rainforest. The seasonal occurrence of long-tongued moths in the study site is related mainly to the income of migrating species from adjacent ecosystems to the HARF. Pollinator-limitation was common in the most specialized sphingophilous plants limiting fruit-set. Pollinator-mediated selection processes in highly specialized species were also impaired. However, local processes of pollinator-mediated selection may operate structuring the morphological match between hawkmoths and plants in spite of being variable in time and space, as suggested by the results. Despite the absence of a strict phenological match between hawkmoths and plants in the Atlantic Rainforest, the general pattern recorded to other analyzed biomes suggests a concurrence of long-tongued hawkmoths and long-tubed flowers through the phenological time. Since this group of plants offers greater amounts of nectar in a "private niche" where only long-tongued hawkmoths can have access, such phenological match could be viewed as a strategy to reduce competition for floral resources between long- and short-tongued moths in the Sphingidae community / Doutorado / Biologia Vegetal / Doutor em Biologia Vegetal

Orientador: Marcos Pereira Marinho Aidar / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-21T19:18:09Z (GMT). No. of bitstreams: 1 Marchiori_NidiaMara_M.pdf: 3439360 bytes, checksum: 8e5d49e665742675abd331ec9cff9ba4 (MD5) Previous issue date: 2012 / Resumo: O Nitrogênio é um nutriente essencial para o crescimento das plantas e produtividade de um ecossistema, visto sua ação como limitante para a fotossíntese ou relação com a reflectância da luz (albedo). Além disso, detém importância ecológica por ser uma ferramenta para a categorização de espécies em classes sucessionais baseado na utilização de suas formas disponíveis. Dessa forma, a compreensão da fisiologia do uso de N é essencial, especialmente em florestas tropicais, onde existem poucos estudos com essa abordagem. A Mata Atlântica (MA) é originalmente a segunda maior floresta tropical do continente americano, contudo grande parte de sua área e biodiversidade foi perdida e atualmente essa Floresta é definida como um "hotspot" para conservação da biodiversidade. O conhecimento e entendimento da estrutura e do funcionamento de ecossistemas complexos como os que compõem a MA é de suma importância para a discussão de temas atuais como o balanço de carbono global, nutrição vegetal e mudanças climáticas. Dentre os principais objetivos foram: a caracterização fitossociológica e estrutural de um trecho de Floresta Ombrófila Densa Montana (FODM), elucidar as estratégias de utilização de nitrogênio pelas plantas e avaliar através de parâmetros foliares, as respostas das plantas frente à mudança da estação do ano e a sazonalidade intrínseca. A área de coleta estava localizada na microbacia Ribeirão Casa de Pedra, Núcleo Santa Virgínia/Parque Estadual da Serra do Mar- São Luiz do Paraitinga, SP. Quanto à estrutura e composição do trecho de FODM estudado pode-se verificar uma floresta em estádio secundário inicial de regeneração avançando para uma condição mais tardia, sendo essa definição baseada tanto no histórico de utilização da área, quanto na composição de espécies e fisiologia do uso de nitrogênio. Assim, os resultados indicaram que em FODM há intensa diversidade biológica e diversidade funcional. Importante ressaltar também que esse projeto de mestrado foi parte integrante do Projeto Temático "Carbon tracker and water availability: controls of land use and climate changes" (Clima - FAPESP 08/58120-3; período de 2009-2013; coordenação Humberto Ribeiro da Rocha), cujo objetivo principal foi a quantificação à longo prazo da dinâmica dos fluxos de água, energia e CO2 em Biomas de Cerrado e Mata Atlântica no sudeste do Brasil / Abstract: Nitrogen is an essencial nutrient for plant growth and ecosystem productivity, either by limiting photosynthesis or related to the light reflectance (albedo). In addition, N has an ecological importance because it can be a tool for the categorization of species in ecological succession and functional types based on the use of its available forms. Thus, understanding the physiology of N use is essential, especially in tropical forests, where despite the impending increase of this element as a result of intensive fertilization or atmospheric deposition there are few studies using this approach. The Atlantic Forest (AF) is originally the second largest rainforest at the America continent, but much of its area and biodiversity has been lost and now the forest is defined as a "hotspot" for biodiversity conservation. The knowledge and understanding of the structure and functioning of complex ecosystems such as those that comprise the AF is of paramount importance for the discussion of current issues as the global carbon balance, plant nutrition and climate change. The main aims were: phytosociological and structural characterization of the tree component in a Montane Tropical Rainforest, understand the strategies of nitrogen use by plants and assess through leaf parameters, the response of plants to the change of season and intrinsic seasonality. The study area of the three chapters that follow are inserted in the watershed Ribeirão Casa de Pedra, Núcleo Santa Virginia Parque Estadual da Serra do Mar, located in São Luiz do Paraitinga-SP. The results indicated that Montane Tropical Rainforest was in initial secondary stage of regeneration evolving to a climax condition, based on the past human disturbance in the area, species composition and physiology of N use. Also indicated that this forest has many species and functional diversity. It is also important to note that this Master's project is part of the Thematic Project "Carbon tracker and water availability: controls of land use and climate changes" (Climate - FAPESP 08/58120-3; period 2009-2013; coordinated by Humberto Ribeiro da Rocha), whose main objective is to quantify the long-term dynamics of fluxes of water, CO2, energy at Cerrado and Atlantic Forest biomes in southeastern Brazil / Mestrado / Biologia Vegetal / Mestra em Biologia Vegetal

Orientador: Luiza Sumiko Kinoshita / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-04T06:25:49Z (GMT). No. of bitstreams: 1 Urbanetz_Catia_M.pdf: 8413873 bytes, checksum: 70e3fcc7a119c7b75401f81d3e1e15ea (MD5) Previous issue date: 2005 / Resumo: o presente trabalho teve como objetivo principal caracterizar a vegetação arbustiva e arbórea de um trecho de Floresta Ombrófila Densa localizado na parte continental do município de Cananéia, vale do Ribeira, SP. Além disso, objetivou contribuir com o conhecimento da Mata Atlântica através da comparação da flora arbórea local com outros levantamentos florísticos da Mata Atlântica e também pela elaboração de uma chave de identificação de espécies baseada em caracteres vegetativos e ilustrada com imagens das espécies. O levantamento florístico foi realizado através de coletas assisternáticas ao longo das trilhas existentes no local. Foram encontradas um total de 189 espécies distribuídas em 122 gêneros e 48 famílias, das quais seis eram palmeiras, 28 arbustos e 155 árvores. As famílias mais ricas foram Myrtaceae (28 espécies), Leguminosae (17), Melastomataceae (15), Rubiaceae (14), Lauraceae (10), Asteraceae e Euphorbiaceae (9), Arecaceae (6), Sapotaceae e Solanaceae (5) e Cecropiaceae (4). Os gêneros mais ricos foram Psychotria (9 espécies), Miconia e Eugenia (8), Inga e Vemonia (6), Myrcia e Ocotea (5), Calyptranthes, Gomidesia e Leandra (4), Solanum e Tibouchina (3). Foram feitas análises de classificação e ordenação aplicadas a uma matriz ílorística para analisar a similaridade entre 24 estudos de Mata Atlântica, incluindo o da Fazenda Folha Larga. Analisando a similaridade florística entre a flora local e a de outras áreas, observou-se maior similaridade florística entre a área estudada e florestas com menor influência marinha e relevos mais acidentados. Os levantamentos realizados sobre áreas com influência marinha (restinga) apareceram diferenciados daqueles feitos em locais com outras condições, indicando um possível gradiente de substituição de espécies da encosta para a restinga, que pode estar relacionado com condições edáficas diferenciais. Por outro lado, não foi encontrada uma separação nítida entre os levantamentos costeiros do norte e os do sul, o que parece confmnar uma substituição contínua de espécies ao longo do gradiente latitudinal da Mata Atlântica. Os resultados obtidos sugerem que é essencial a preservação de áreas ao longo de toda a distribuição da Mata Atlântica, uma vez que sua composição floristica é bastante complexa e não pode ser adequadamente representada por pequenas áreas localizadas. Uma chave de identificação de espécies para 188 espécies lenhosas também está apresentada, baseada em caracteres vegetativos, tais como filotaxia, tipo de folha, formato de folha, estípulas, indumento, exsudados, glândulas e pontuações. A maioria das espécies (84%) foi facilmente separada na chave e somente algumas espécies (29) não puderam ser distinguidas utilizando-se estes caracteres. Algumas espécies apareceram mais de uma vez na chave por terem apresentado uma variação de alguns caracteres, tais como margem da folha e filotaxia. Embora haja uma variação considerável Da composição entre os levantamentos, a chave ainda pode ser útil em outras áreas desde que as mesmas possuam certo número de espécies em comum. Foram feitas imagens de ramos em estado reprodutivo de 122 espécies de modo a auxiliar na identificação da das espécies da chave / Abstract: The aim of this study was to investigate the floristic composition of a Rain Forest fi:agment in the Fazenda Folha Larga, located in Cananéia municipality in the vale do Ribeira, state of São Paulo, Brazil, and to compare it with a number of other floristic surveys from this formation. In addition, the construction of a species identification key based on vegetative characters with images of the species was proposed. ln the tloristic survey plants were collected using assystematic sampling along trails. A total of 189 species distributed in 122 genera and 48 families was found: ofthese, six were palms, 28 shrnbs and 155 trees. At family leveI, the greatest species richness was found in Myrtaceae (28 species), Leguminosae (17), Melastomataceae (15), Rubiaceae (14) and Lauraceae (10), while at generic levei, Psychotria (9 species), Miconia and Eugenia (8), Inga and Vernonia (6), Myrcia and Ocotea (5), Calyptranthes, Gomidesia and Leandra (4) were the most species .rich genera. Classification and ordination analysis were applied to a t1oristíc matrÍx in order to analyze the similarity among 24 surveys, including Fazenda Folha Larga. Analyzing the tloristic similarity between this forest and the other Atlantic Rain F orest areas, a hígher tloristic similarity was observed between Fazenda Folha Larga and those areas which showed less marine intluence and more rugged relief. The surveys in areas with greater marine influence (restinga) were separated from those in other conditions, possibly indicating a species replacement gradient from the steeper slopes towards restinga, and this 1S probably related to different edaphic conditions. On the other hand, no clear separation was found among the surveys located on the north and the south coast, apparent1y confmning continuous species replacement along the Atlantic Rain Forest latitudinal gradient. This suggests that it is essential to preserve areas from the whole of the Atlantic Rain Forest distribution as if s composition is quite complex and is not adequateIy represented by small localized areas. An identification key for 189 woody species is also presented, using morphological vegetative characters such as phyllota:x.y, leaf type and shape, stipules, indument, exudates, presence of glands and dots. The majority of the species were easily separated in the key and onIy some species could not be distinguished using these characters. Some species appeared more than once in the key because they showed great variation in some characters such as leaf margin and phyllotaxy. Although there 15 a considerable variation in composition amongst surveys, the key should still be useful in other areas since they have a number of species in common. Images ofreproductive branches from 122 species were made in order to help with their identification / Mestrado / Biologia Vegetal / Mestre em Biologia Vegetal

Detailed understanding of the equation of state of light elements such as the hydrogen isotopes in the warm dense matter (WDM) regime is essential for the modeling of the inner structure of many astrophysical objects, in particular Jovian planets as well as inertial confinement fusion (ICF) research. In these systems quantum degeneracy and strong inter-particle forces play an important role making its theoretical description extremely challenging. The Omega laser was used to drive a planar shock wave in cryogenically cooled deuterium creating WDM conditions. We used a set of independent diagnostics to measure the thermodynamic conditions of WDM including velocity interferometry (VISAR), streaked optical pyrometry (SOP) and x-ray Thomson scattering (XRTS). With a narrow-band x-ray backlighter probe at backscattering geometry the spectrally resolved XRTS accessed the boundary of collective and non-collective regimes making our measurement sensitive to both electron temperature and density. This work presents a full set of measurements of the thermodynamic properties for different laser intensity drives creating warm dense deuterium at various degrees of degeneracy and coupling. The measured electron densities and temperatures ranged between 0.2 and 2.15x10²³ cm^−3 and 0.6 − 20 eV respectively. The scattering measurement confirmed the findings from the VISAR and SOP data and together densityfunctional molecular dynamics (DFT-MD) simulations provides a novel self-consistent approach for an accurate characterization of the microscopic structure of WDM. Complementary to the laser compression work, findings from project employing static compression hydrogen with the use of diamond anvil cells is also be presented. The first direct measurement of the local field correction to the Coulomb interactions in degenerate plasma was obtained from inelastic scattering (20 keV probe) at the Diamond Light Source synchrotron facility.

Par rapport à un fluide Newtonien, les suspensions denses de particules présentent des propriétés rhéologiques différentes. Des comportements rhéofluidifiants ou rhéoépaississants liés à des phénomènes de migration de particules peuvent apparaitre. Pour des suspensions, le taux de cisaillement, la concentration et la taille des particules ont une grande influence sur ce comportement rhéologique (Denn et Morris 2014). Pour observer l'influence de ces facteurs, l'un des meilleurs moyens est de disposer d’un système simple dans lequel tous les facteurs mentionnés ci-dessus sont bien contrôlés. Ceci peut être réalisé par le développement d'une plate-forme expérimentale, sur laquelle les comportements d'écoulement de suspension (profil de vitesse et concentration locale de particules) à des vitesses de cisaillement et des concentrations de particules bien contrôlées peuvent être étudiés. Dans l'étude actuelle, 4 tâches ont été réalisées :1) Le développement d'une nouvelle formulation pour la préparation d’une suspension adaptée en indice de réfraction et en densité basée sur des particules de PMMA. 2) Le développement d'un dispositif expérimental consacré à l'étude des flux de suspension dense sous une large gamme de taux de cisaillement constant. 3) La caractérisation des profils de vitesse des flux de suspension dense sous un dispositif cône-plan utilisant des techniques de micro-PIV. 4) Une mesure préliminaire de la concentration locale de particules de la suspension sous écoulement cône-plan en utilisant des méthodes de traitement d'image. / Compared to general Newtonian fluids, highly concentrated mixtures of particles and fluid, so called dense suspensions, have different rheological properties and fluid dynamic behaviors. Such as, shear-thinning or shear-thickening effect, and apparent slip and particle migration behaviors under certain shear flow conditions. These properties are related to the application of suspension flow in real systems, for example, the blood.For suspensions, shear rate, particle concentration and particle size have a big influence of on their rheological behaviors (Denn and Morris 2014). To observe the influence of these factors, one of the best ways is to start the research from a simple case in which all the above mentioned factors are well controlled. This can be realized by developing such an experimental platform, on which the suspension flow behaviors (velocity profile and local particle concentration) at different shear rates and particle concentrations can be investigated.In the current study, 4 tasks were achieved:1) The development of a new recipe for the preparation of density and refractive index matched suspension with PMMA particles. 2) The development of an experimental set-up devoted to the investigation of dense suspension flow under a large range of constant shear rate. 3) The characterization of the velocity profiles of dense suspension flows under a cone-plate device by using micro-PIV techniques.4) A preliminary measurement of the local particle concentration of the suspension flow by using image processing techniques.

A range space (P, S) consists of a set P of n elements and a collection S = {S1,...,Sm} of subsets of P , referred to as ranges. A hitting set for this range space refers to a subset H of P such that every Si in S contains at least one element of H. The hitting set problem is studied for many geometric range spaces where P is a set of n points in Rd and the ranges are defined by the intersection of geometric objects with P . The algorithmic question of finding the minimum-sized hitting set for a given range space is well studied and is NP-Complete even for geometric range spaces defined by unit disks. The dual of the hitting set problem is the equally well studied set cover problem. A set cover is a sub-collection C⊆S such that every element in P is contained in at least one range in C. A classic problem which is related to the minimum set cover problem is the maximum coverage problem. In this problem, given a range space (P, S) and an integer k, we have to find k ranges from S such that the number of elements in P that are covered by these k ranges are maximized. In this thesis, we study combinatorial questions on a similar variant of hitting set problem for specific geometric range spaces where the size of the hitting set is fixed as a small constant. We study the small hitting set problem mainly for two broad classes of range spaces. We first consider the Dense range space (P, S) where P is a set of n points in Rd and S is defined by “dense” geometric objects i.e, geometric objects that contain more than a constant fraction, say �, of points from P . We fix the size of the hitting set as a small constant k and investigate bounds on the value of � such that all ranges that contain more than �n points from P are hit. Next we consider the Induced range space (P, I) where P isa setof n points in R2 and the ranges are all geometric objects that are induced(spanned) by P i.e., the ranges are defined by geometric objects that have a distinct tuple of points from P on its boundary. For Induced range spaces, we prove bounds on the maximum number of ranges that can be hit using a single point. We also prove combinatorial bounds on the size of the hitting set for various families of induced objects. Now, we describe the problems that we study in this thesis and summarize the results obtained. 1. Strong centerpoints: Here we study the small hitting set question for dense range spaces when the size of hitting set is one. This is related to a classic result in geometry called Centerpoint Theorem. A point x ∈ Rd is said to be the centerpoint of P if x is contained in all convex objects that contain more than dn points from P . Centerpoint Theorem states d+1 that a centerpoint always exists for any point set P . A centerpoint need not be an input point. A natural question to ask is the following: Does there exist a strong centerpoint? i.e., is it true that for any given point set P there exists a point p ∈ P such that p is contained in every convex object that contains more than a constant fraction, say �, of points of P ? It can be easily seen that a strong centerpoint does not exist even for geometric range spaces defined by half spaces. We study the existence and the corresponding bounds for strong centerpoints for some range spaces. In particular, we prove the existence of strong centerpoint and show tight bounds for the following range spaces. Convex polytopes defined by a fixed set of orientations : Geometric range spaces like those induced by axis-parallel boxes, skylines and downward facing equilateral triangles belong to this family of convex polytopes. Hyperplanes in Rd Range spaces with discrete intersection 2. Small Strong Epsilon Nets: This can be considered as an extension of strong centerpoints. This question is related to a well studied area called �-nets. N ⊂ P is called a (strong) �-net of P with respect to S if N ∩ S =�∅ for all objects S ∈S that contain more than �n points of P . We study the following question. Let �S∈ [0, 1] represent the smallest real number such that, for any given point set P , there exists Q ⊂ P of size i which is an �S-net with respect to S. Thus a strong centerpoint will be an �S1 -net. We prove bounds on �Si for small values of i where S is the family of axis-parallel rectangles, halfspaces and disks. 3. Strong First Selection Lemma: Here we consider the hitting question for induced range spaces when the size of the hitting set is one. In other words, given an induced range space, we prove bounds on the maximum number of ranges that can be hit using a single input point. Such questions are referred to as First Selection Lemma and are well studied. We consider the strong version of the First Selection Lemma where the “heavily covered” point is required to be an input point. We study the strong first selection lemma for induced rectangles, induced special rectangles and induced disks. We prove an exact result for the strong variant of the first selection lemma for axis-parallel rectangles. We also prove exact results for the strong variant of the first selection lemma for some subclasses of axis-parallel rectangles like orthants and slabs. We prove strong first selection lemma with almost tight bounds for skylines, another sub-class of axis-parallel rectangles. We prove bounds for first selection lemma for disks in the plane and exact results for a special case when the discs are induced by a centrally symmetric point set. 2 Hitting all Induced Objects: Here we discuss and prove combinatorial bounds on the size of the minimum hitting set for induced range spaces. We prove tight bounds on the hitting set size when induced objects are special rectangles, disks and downward facing equilateral triangles.

Abstract : Images acquired from unmanned aerial vehicles (UAVs) can provide data with unprecedented spatial and temporal resolution for three-dimensional (3D) modeling. Solutions developed for this purpose are mainly operating based on photogrammetry concepts, namely UAV-Photogrammetry Systems (UAV-PS). Such systems are used in applications where both geospatial and visual information of the environment is required. These applications include, but are not limited to, natural resource management such as precision agriculture, military and police-related services such as traffic-law enforcement, precision engineering such as infrastructure inspection, and health services such as epidemic emergency management. UAV-photogrammetry systems can be differentiated based on their spatial characteristics in terms of accuracy and resolution. That is some applications, such as precision engineering, require high-resolution and high-accuracy information of the environment (e.g. 3D modeling with less than one centimeter accuracy and resolution). In other applications, lower levels of accuracy might be sufficient, (e.g. wildlife management needing few decimeters of resolution). However, even in those applications, the specific characteristics of UAV-PSs should be well considered in the steps of both system development and application in order to yield satisfying results. In this regard, this thesis presents a comprehensive review of the applications of unmanned aerial imagery, where the objective was to determine the challenges that remote-sensing applications of UAV systems currently face. This review also allowed recognizing the specific characteristics and requirements of UAV-PSs, which are mostly ignored or not thoroughly assessed in recent studies. Accordingly, the focus of the first part of this thesis is on exploring the methodological and experimental aspects of implementing a UAV-PS. The developed system was extensively evaluated for precise modeling of an open-pit gravel mine and performing volumetric-change measurements. This application was selected for two main reasons. Firstly, this case study provided a challenging environment for 3D modeling, in terms of scale changes, terrain relief variations as well as structure and texture diversities. Secondly, open-pit-mine monitoring demands high levels of accuracy, which justifies our efforts to improve the developed UAV-PS to its maximum capacities. The hardware of the system consisted of an electric-powered helicopter, a high-resolution digital camera, and an inertial navigation system. The software of the system included the in-house programs specifically designed for camera calibration, platform calibration, system integration, onboard data acquisition, flight planning and ground control point (GCP) detection. The detailed features of the system are discussed in the thesis, and solutions are proposed in order to enhance the system and its photogrammetric outputs. The accuracy of the results was evaluated under various mapping conditions, including direct georeferencing and indirect georeferencing with different numbers, distributions and types of ground control points. Additionally, the effects of imaging configuration and network stability on modeling accuracy were assessed. The second part of this thesis concentrates on improving the techniques of sparse and dense reconstruction. The proposed solutions are alternatives to traditional aerial photogrammetry techniques, properly adapted to specific characteristics of unmanned, low-altitude imagery. Firstly, a method was developed for robust sparse matching and epipolar-geometry estimation. The main achievement of this method was its capacity to handle a very high percentage of outliers (errors among corresponding points) with remarkable computational efficiency (compared to the state-of-the-art techniques). Secondly, a block bundle adjustment (BBA) strategy was proposed based on the integration of intrinsic camera calibration parameters as pseudo-observations to Gauss-Helmert model. The principal advantage of this strategy was controlling the adverse effect of unstable imaging networks and noisy image observations on the accuracy of self-calibration. The sparse implementation of this strategy was also performed, which allowed its application to data sets containing a lot of tie points. Finally, the concepts of intrinsic curves were revisited for dense stereo matching. The proposed technique could achieve a high level of accuracy and efficiency by searching only through a small fraction of the whole disparity search space as well as internally handling occlusions and matching ambiguities. These photogrammetric solutions were extensively tested using synthetic data, close-range images and the images acquired from the gravel-pit mine. Achieving absolute 3D mapping accuracy of 11±7 mm illustrated the success of this system for high-precision modeling of the environment. / Résumé : Les images acquises à l’aide d’aéronefs sans pilote (ASP) permettent de produire des données de résolutions spatiales et temporelles uniques pour la modélisation tridimensionnelle (3D). Les solutions développées pour ce secteur d’activité sont principalement basées sur des concepts de photogrammétrie et peuvent être identifiées comme des systèmes photogrammétriques embarqués sur aéronefs sans pilote (SP-ASP). Ils sont utilisés dans plusieurs applications environnementales où l’information géospatiale et visuelle est essentielle. Ces applications incluent notamment la gestion des ressources naturelles (ex. : agriculture de précision), la sécurité publique et militaire (ex. : gestion du trafic), les services d’ingénierie (ex. : inspection de bâtiments) et les services de santé publique (ex. : épidémiologie et gestion des risques). Les SP-ASP peuvent être subdivisés en catégories selon les besoins en termes de précision et de résolution. En effet, dans certains cas, tel qu’en ingénierie, l’information sur l’environnement doit être de haute précision et de haute résolution (ex. : modélisation 3D avec une précision et une résolution inférieure à un centimètre). Pour d’autres applications, tel qu’en gestion de la faune sauvage, des niveaux de précision et de résolution moindres peut être suffisants (ex. : résolution de l’ordre de quelques décimètres). Cependant, même dans ce type d’applications les caractéristiques des SP-ASP devraient être prises en considération dans le développement des systèmes et dans leur utilisation, et ce, pour atteindre les résultats visés. À cet égard, cette thèse présente une revue exhaustive des applications de l’imagerie aérienne acquise par ASP et de déterminer les challenges les plus courants. Cette étude a également permis d’établir les caractéristiques et exigences spécifiques des SP-ASP qui sont généralement ignorées ou partiellement discutées dans les études récentes. En conséquence, la première partie de cette thèse traite des aspects méthodologiques et d’expérimentation de la mise en place d’un SP-ASP. Le système développé a été évalué pour la modélisation précise d’une gravière et utilisé pour réaliser des mesures de changement volumétrique. Cette application a été retenue pour deux raisons principales. Premièrement, ce type de milieu fournit un environnement difficile pour la modélisation, et ce, en termes de changement d’échelle, de changement de relief du terrain ainsi que la grande diversité de structures et de textures. Deuxièment, le suivi de mines à ciel ouvert exige un niveau de précision élevé, ce qui justifie les efforts déployés pour mettre au point un SP-ASP de haute précision. Les composantes matérielles du système consistent en un ASP à propulsion électrique de type hélicoptère, d’une caméra numérique à haute résolution ainsi qu’une station inertielle. La composante logicielle est composée de plusieurs programmes développés particulièrement pour calibrer la caméra et la plateforme, intégrer les systèmes, enregistrer les données, planifier les paramètres de vol et détecter automatiquement les points de contrôle au sol. Les détails complets du système sont abordés dans la thèse et des solutions sont proposées afin d’améliorer le système et la qualité des données photogrammétriques produites. La précision des résultats a été évaluée sous diverses conditions de cartographie, incluant le géoréférencement direct et indirect avec un nombre, une répartition et des types de points de contrôle variés. De plus, les effets de la configuration des images et la stabilité du réseau sur la précision de la modélisation ont été évalués. La deuxième partie de la thèse porte sur l’amélioration des techniques de reconstruction éparse et dense. Les solutions proposées sont des alternatives aux techniques de photogrammétrie aérienne traditionnelle et adaptée aux caractéristiques particulières de l’imagerie acquise à basse altitude par ASP. Tout d’abord, une méthode robuste de correspondance éparse et d’estimation de la géométrie épipolaire a été développée. L’élément clé de cette méthode est sa capacité à gérer le pourcentage très élevé des valeurs aberrantes (erreurs entre les points correspondants) avec une efficacité de calcul remarquable en comparaison avec les techniques usuelles. Ensuite, une stratégie d’ajustement de bloc basée sur l’intégration de pseudoobservations du modèle Gauss-Helmert a été proposée. Le principal avantage de cette stratégie consistait à contrôler les effets négatifs du réseau d’images instable et des images bruitées sur la précision de l’autocalibration. Une implémentation éparse de cette stratégie a aussi été réalisée, ce qui a permis de traiter des jeux de données contenant des millions de points de liaison. Finalement, les concepts de courbes intrinsèques ont été revisités pour l’appariement stéréo dense. La technique proposée pourrait atteindre un haut niveau de précision et d’efficacité en recherchant uniquement dans une petite portion de l’espace de recherche des disparités ainsi qu’en traitant les occlusions et les ambigüités d’appariement. Ces solutions photogrammétriques ont été largement testées à l’aide de données synthétiques, d’images à courte portée ainsi que celles acquises sur le site de la gravière. Le système a démontré sa capacité a modélisation dense de l’environnement avec une très haute exactitude en atteignant une précision 3D absolue de l’ordre de 11±7 mm.

En condition accidentelle,le combustible nucléaire d’un réacteur peut entrer en contact avec le fluide caloporteur.Les conséquences de l’interaction qui en résulte sont étudiées par l’IRSN. La violence de l’interaction dépend notamment fortement de la cinétique de cette mise en contact. L’observation expérimentale directe du phénomène étant inenvisageable. Ce travail de thèse a consisté en l’étude de cette dynamique. Nous avons étudié le débit de vidange d’un milieu granulaire monodisperse en fonction de plusieurs paramètres prépondérants (géométrie du réservoir,taille,forme et position de l’orifice,débit gazeux,taille des grains). Ces études ont été réalisées sur un banc expérimental dédié et ont mis en évidence plusieurs lois d’échelle pour le régime stationnaire. En support à l’interprétation de ces expériences, différentes hypothèses de modélisation de l’écoulement (population discrète de particules, rhéologie d’un milieu continu) ont été confrontées aux résultats expérimentaux à l’aide de simulations numériques. Ainsi la loi de dépendance classique du débit de vidange d’un silo avec un orifice en bas a été étendue aux silos avec un orifice latéral notamment en clarifiant les contributions relatives aux dimensions verticale et horizontale. Par ailleurs, il a été établi qu’un écoulement de gaz augmente significativement le débit de vidange du granulaire. Ceci peut être modélisé en prenant en compte le gradient de pression imposé par le gaz sur les grains dans la zone de l’orifice en plus de la gravité. Les éléments fondateurs de la modélisation d’une vidange de grains et de gaz au sein d’un réservoir avec un orifice latéral ont pu ainsi être mis en place. / In the hypothetical conditions of a reactivity initiated accident in a nuclear power plant, some of the cylindrical rods, that contain the fuel, could break. If fuel fragmentation occurs, hot fuel particles and pressurized gas could be ejected out of the rod and then interact with the surrounding fluid. The consequences of this interaction are studied by IRSN . The violence of this interaction depends particularly on the discharge rate of the fuel particles. The aim of this thesis, was to study this dynamics. We simulated the fuel particles and gas ejection dynamics by the flow of a dense granular material and a gas from a confined space toward an open space. We focused on the experimental study of the stationary discharge of a silo composed of monodisperse spherical glass beads, with an orifice either lateral or at the bottom of the silo, with or without air flow. The measured parameters were the mass flow rate and the pressure along the silo, whereas the controlled parameters were the size of particles, the size of orifices, and the flow rate of air. To understand the underlying physical mechanism, discrete and continuous numerical simulations were also performed and compared to the experimental results. For the case of a lateral orifice, when the form of the orifice is rectangular, we identified two regimes that depend on the ratio of width to height. For the case with air flow, we found that the flow rate increases significantly with the air flow. We used a simple physical model to describe the grains and gas ejection taking into account the pressure gradient imposed by the fluid on the particles around the orifice.

Nous nous intéressons dans cette thèse au problème de l'estimation dense du mouvement dans des séquences d'images, également désigné sous le terme de flot optique. Les approches usuelles exploitent une paramétrisation locale ou une régularisation globale du champ de déplacement. Nous explorons plusieurs façons de combiner ces deux stratégies, pour surmonter leurs limitations respectives. Nous nous plaçons dans un premier temps dans un cadre variationnel global, et considérons un filtrage local du terme de données. Nous proposons un filtrage spatialement adaptatif, optimisé conjointement au mouvement, pour empêcher le sur-lissage induit par le filtrage spatialement constant. Dans une seconde partie, nous proposons un cadre générique d'agrégation pour l'estimation du flot optique. Sous sa forme générale, il consiste en une estimation locale de candidats de mouvements, suivie de leur combinaison à l'étape d'agrégation avec un modèle global. Ce schéma permet une estimation efficace des grands déplacements et des discontinuités de mouvement. Nous développons également une méthode générique de gestion des occultations. Notre méthode est validée par une analyse expérimentale conséquente sur des bases de données de référence en vision par ordinateur. Nous démontrons la supériorité de notre méthode par rapport à l'état de l'art sur les séquences présentant de grands déplacements. La dernière partie de la thèse est consacrée à l'adaptation des approches précédentes à des problématiques d'imagerie biologique. Les changements locaux importants d'intensité observés en imagerie de fluorescence sont estimés et compensé par une adaptation de notre schéma d'agrégation. Nous proposons également une méthode variationnelle avec filtrage local dédiée au cas de mouvements diffusifs de particules. / This thesis is concerned with dense motion estimation in image sequences, also known as optical flow. Usual approaches exploit either local parametrization or global regularization of the motion field. We explore several ways to combine these two strategies, to overcome their respective limitations. We first address the problem in a global variational framework, and consider local filtering of the data term. We design a spatially adaptive filtering optimized jointly with motion, to prevent over-smoothing induced by the spatially constant approach. In a second part, we propose a generic two-step aggregation framework for optical flow estimation. The most general form is a local computation of motion candidates, combined in the aggregation step through a global model. Large displacements and motion discontinuities are efficiently recovered with this scheme. We also develop a generic exemplar-based occlusion handling to deal with large displacements. Our method is validated with extensive experiments in computer vision benchmarks. We demonstrate the superiority of our method over state-of-the-art on sequences with large displacements. Finally, we adapt the previous methods to biological imaging issues. Estimation and compensation of large local intensity changes frequently occurring in fluorescence imaging are efficiently estimated and compensated with an adaptation of our aggregation framework. We also propose a variational method with local filtering dedicated to the case of diffusive motion of particles.

Meiosis is a specialized cell division that produces haploid cells (gametes) from diploid progenitors. During meiosis parental chromosomes (homologs) need to pair, synapse and eventually segregate. Faithful chromosome segregation depends on chromosome recombination. In the beginning of prophase I programmed double strand breaks (DSBs) are introduced in meiotic cells by SPO11 enzyme. DSBs are positioned at hotspot sites that are specified by that action of DNA-binding histone methyltransferase PRDM9. Specific enzymes act at the site of breaks to create 5’ single stranded DNA ends. With the assistance of the strand exchange proteins DMC1 and RAD51 these ends invade homologous DNA sequence and DSB repair is initiated. DSB repair can be completed either as a crossover (reciprocal exchange of DNA) or as a non-crossover. Crossover events lead to the formation of chiasmata between homologs and ensure proper segregation during the first meiotic division. An interesting feature in male meiosis is the XY chromosomes. The shared region between sex chromosomes is short and is called pseudoautosomal region (PAR). Due to their large non synapsed region, XY chromosomes need to be transcriptionally silenced. Thus they are covered with the phosphorylated histone variant H2AX (γH2AX) forming the so called sex body. PAR region has higher density of DSBs than autosomes and it had been shown that sex chromosomes undergo delayed homologous pairing. Nevertheless little is known how meiotic recombination is regulated in PAR region of sex chromosomes. In close proximity with sex body it has been found a structure named dense body (DB). There are few reports suggesting that DB contains RNAs/proteins but no DNA. Its role in meiosis was unclear because no structural component had been described. In the present thesis the role of two meiotic expressed genes is described. In our group after performing RNA screens we identified several genes that are highly expressed during meiotic prophase I. Based on the expression profile we selected polycomb-related sex comb on midleg like 1 (Scml1) gene and the ankyrin repeat domain 31 (Ankrd31) to study their role in mammalian meiosis.:List of figures i List of abbreviations ii 1. Introduction 1 1.1 Gametogenesis 1 1.2 Meiotic prophase I 2 1.2.1 Meiotic recombination 4 1.2.2 Regulation of meiotic recombination 7 1.2.2.1 Meiotic recombination hotspots and PRDM9 activity 7 1.2.2.2 Meiotic surveillance mechanisms 8 1.3 Unique properties of XY recombination 9 1.4 Sex chromatin associated structure: The dense body 10 1.5 Aim of the thesis 11 2. Publications 12 3. Discussion 92 4. Summary 98 5. References 102 Acknowledgements 108 Declarations 109