Dans la présente thèse nous étudions l'extraction d'arbres dans des graphes arêtes-coloriés.Nous nous concentrons sur la recherche d'arbres couvrants proprement arête-coloriés et faiblement arête-coloriés, notée PST et WST. Nous montrons que les versions d'optimisation de ces problèmes sont NP-Complete dans le cas général des graphes arêtes-coloriés, et nous proposons des algorithmes pour trouver ces arbres dans le cas des graphes arêtes-coloriés sans cycles proprement arêtes-coloriés.Nous donnons également quelques limites de nonapproximabilité. Nous proposons des conditions suffisantes pour l'existence de la PST dans des graphes arêtes-coloriés (pas forcément propre), en fonction de différents paramètres de graphes, tels que : nombre total de couleurs, la connectivité et le nombre d'arêtes incidentes dedifférentes couleurs pour un sommet. Nous nous intéressons aux chemins hamiltoniens proprement arêtes-coloriés dans le casdes multigraphes arêtes-coloriés. Ils présentent de l'intérêt pour notre étude, car ce sontégalement des arbres couvrants proprement arêtes-coloriés. Nous établissons des conditions suffisantes pour qu'un multigraphe contienne un chemin hamiltonien proprement arêtes-coloriés, en fonction de plusieurs paramètres tels que le nombre d'arêtes, le degré d'arêtes, etc. Puisque l'une des conditions suffisantes pour l'existence des arbres couvrants proprement arêtes-coloriés est la connectivité, nous prouvons plusieurs bornes supérieures pour le plus petit nombre de couleurs nécessaires pour la k-connectivité-propre. Nous énonçons plusieurs conjectures pour les graphes généraux et bipartis, et on arrive à les prouver pour k = 1.

Due to shared coevolutionary history of snakes and primates with snakes acting as their main predators, snakes elicit fear in most of the primates, humans included. Humans are able to notice a stimulus that elicits fear, e.g., a snake, much faster. Such ability might have surely positively affected their survival in the past. In the nature, aposematic coloration acts as a warning of a dangerous prey to its predators not to devour it. The highly poisonous American coral snakes have this coloration pattern. The harmless king snakes of the Central and North Americas gain an anti-predatory advantage by becoming the coral snakes 'Batesian mimics, copying their bright pattern. Such pattern elicits an innate fear reaction in various species of wild birds who avoid a mere contact with patterned plastic dummies. The question arises whether other taxa, including primates and humans, generally recognize such pattern as dangerous. The aim of this study was to find whether humans fear coral snakes, although they have not long coevolutionary history with them. Further it was analyze, which visual factors of the snakes affect this fear reaction (i.e., a warning coloration, pattern or shape of snake). The atractiveness of these snakes was tested. Another question was whether humans are able to intuitively recognize...

This research explored a Digital Laser Dye (DLD) patterning process as an alternative coloration method within a textile design practice context. An interdisciplinary framework employed to carry out the study involved Optical Engineering, Dyeing Chemistry, Textile Design and Industry Interaction through collaboration with the Society of Dyers and Colourists. In doing so, combined creative, scientific and technical methods facilitated design innovation. Standardized polyester (PET) knitted jersey and plain, woven fabrics were modified with CO2 laser technology in order to engineer dye onto the fabric with high-resolution graphics. The work considered the aesthetic possibilities, production opportunities and environmental potential of the process compared to traditional and existing surface design techniques. Laser-dyed patterns were generated by a digital dyeing technique involving CAD, laser technology and dye practices to enable textile coloration and patterning. An understanding of energy density was used to define the tone of a dye in terms of colour depth in relation to the textile. In doing so, a system for calibrating levels of colour against laser energy in order to build a tonal image was found. Central to the investigation was the consideration of the laser beam spot as a dots-per-inch tool, drawing on the principles used in digital printing processes. It was therefore possible to utilise the beam as an image making instrument for modifying textile fibres with controlled laser energy. Qualitative approaches employed enabled data gathering to incorporate verbal and written dialogue based on first-hand interactions. Documented notes encompassed individual thought and expression which facilitated the ability to reflect when engaged in practical activity. As such, tacit knowledge and designerly intuition, which is implicit by nature, informed extended design experiments and the thematic documentation of samples towards a textile design collection. Quantitative measurement and analysis of the outcomes alongside creative exploration aided both a tacit understanding of, and ability to control processing parameters. This enabled repeatability of results parallel to design development and has established the potential to commercially apply the technique. Sportswear and intimate apparel prototypes produced in the study suggest suitable markets for processing polyester garments in this way.

The dissertation thesis deals with human aesthetic preference to other species and its anthropological and conservation aspect. The aesthetic preference to animal species has rarely been systematically studied before and quantitative analyses, especially on a fine taxonomic scale did not exist. On the other hand, it was known that attractive species often receive more support for their conservation. From these simple facts rose the idea to test human aesthetic preference to snake species (and consequently to species across major vertebrate taxa) and use this quantified preference to explain the conservation effort devoted to captive breeding worldwide (measured as size of zoo populations). We confirmed that the perceived attractiveness (preference and/or species' body size) succesfully predicts the size of zoo populations across mammal, bird and reptile taxa. On contrary, we found no effect of the IUCN listing of the species. To find out whether we work with Czech students' preference only or we may generalize to other populations, we carried out the same experiment to determine human preference to boas and pythons in eight cultures of five continents. Despite profound differences of the studied ethnics, we revealed a considerable agreement. Moreover, we found an agreement between pre-school...

J'ai étudié trois problèmes d'optimisation dans les graphes et les jeux combinatoires.Tout d'abord, les codes identifiants dans les graphes où les sommets font faces à des failles: les codes cherchent à repérer les failles pour les réparer. On s'est intéressé aux codes identifiants dans les graphes circulants en utilisant des plongements de ces graphes dans des grilles infinies.Ensuite, j'ai étudié le jeu de marquage de sommets et le jeu de coloration d'arêtes: ici deux joueurs se font face, le premier cherche à construire une coloration correcte (ou un marquage correct) et le deuxième cherche à l'en empêcher. Pour le jeu de marquage on s'est intéressé aux changements de stratégie gagnante lorsqu'on modifie le graphe. Pour le jeu de coloration d'arêtes on a donné une stratégie gagnante pour le premier joueur pourvu que le graphe considéré admette une certaine décomposition sur les arêtes. On améliore notamment des résultats sur les graphes planaires.Enfin j'ai étudié les jeux à tas purement de casse: deux joueurs à tour de rôle prennent un tas et le cassent en un certain nombre de tas non vides. On s'intéresse aux stratégies gagnantes lorsque les joueurs jouent sur un unique tas contenant n jetons. Ces jeux de pure casse semblent, à l'oeil nu, être réguliers. On a montré que c'est effectivement le cas pour certains et on a donné un test qui permet de déterminer la régularité cas par cas. Un seul cas ne semble pas correspondre à cette régularité: son comportement reste un mystère.En conclusion, je me suis intéressé à trois problèmes bilatéraux qui utilisent différentes méthodes et qui remplissent des propos différents dans le domaine de la combinatoire / I studied three optimization problems on graphs and combinatorial games.First, identifying codes were studied : vertices couteract faults. Identifying codes help locate the fault to repare it. We focused on circulant graphs by embedding them on infinite grids.Then, the marking and the coloring games were studied : two player games were one player wants to build something (a proper coloration or a proper marking) and the other wants to prevent the first player from doing so. For the marking game we studied the evolution of the strategy when modifying the graph. For the coloring game we defined a new edge-wise decomposition of graphs and we defined a new strategy on this decomposition that improves known results on planar graphs.In the end, I studied pure breaking games : two players take turns to break a heap of tokens in a given number of non-empty heaps. We focused on winning strategies for the game starting with a unique heap on n tokens. These games seem, on first sight, to be all regular : we showed this is the case for some of them and we gave a test to study one game at a time. Only one of these games does not seem to be regular, its behavior remains a mystery.To sum up, I studied three bilateral problems that use different methods and have different purposes in combinatorics

Dans cette thèse, nous étudions des problèmes de transversaux d'un point de vue tant algorithmique que combinatoire. Etant donné un hypergraphe, un transversal est un ensemble de sommets qui touche toutes les hyperarêtes. Un packing est un ensemble d'hyperarêtes deux à deux disjointes. Alors que la taille minimale d'un transversal est au moins égale à la taille maximale d'un packing on ne peut pas dans le cas général borner la taille minimale d'un transversal par une fonction du packing maximal. Dans un premier temps, un état de l'art rappelle les différentes conditions qui assurent l'existence de bornes supérieures sur la taille des transversaux, en particulier en fonction de la taille d'un packing. La plupart d'entre elles sont valables lorsque la VC-dimension de Vapnik-Chervonenkis de l'hypergraphe, est bornée. L'originalité de la thèse consiste à utiliser ces outils d'hypergraphes pour obtenir des résultats sur des problèmes de graphes. Nous prouvons notamment une conjecture de coloration de Scott dans le cas des graphes sans-triangle maximaux; ensuite, nous généralisons un résultat de Chepoi, Estellon et Vaxès traitant de domination à grande distance; enfin nous nous attaquons à une conjecture de Yannakakis sur la séparation des cliques et des stables d'un graphe.Dans un second temps, nous étudions les transversaux d'un point de vue algorithmique. On se concentre plus particulièrement sur les problèmes de séparation de graphe où on cherche des transversaux à un ensemble de chemin. En combinant des outils de connexité, les séparateurs importants et le théorème de Dilworth, nous obtenons un algorithme FPT pour le problème Multicut paramétré par la taille de la solution. / In this manuscript we study hitting sets both from a combinatorial and from an algorithmic point of view. A hitting set is a subset of vertices of a hypergraph which intersects all the hyperedges. A packing is a subset of pairwise disjoint hyperedges. In the general case, there is no function linking the minimum size of a hitting set and a maximum size of a packing.The first part of this thesis is devoted to present upper bounds on the size of hitting sets, in particular this upper bounds are expressed in the size of the maximum packing. Most of them are satisfied when the dimension of Vapnik-Chervonenkis of the hypergraph is bounded. The originality of this thesis consists in using these hypergraph tools in order to obtain several results on graph problems. First we prove that a conjecture of Scott holds for maximal triangle-free graphs. Then we generalize a result of Chepoi, Estellon and Vaxès on dominating sets at large distance. We finally study a conjecture of Yannakakis and prove that it holds for several graph subclasses using VC-dimension.The second part of this thesis explores algorithmic aspects of hitting sets. More precisely we focus on parameterized complexity of graph separation problems where we are looking for hitting sets of a set of paths. Combining connectivity tools, important separator technique and Dilworth's theorem, we design an FPT algorithm for the Multicut problem parameterized by the size of the solution.

Nos estudos sobre a teoria da Seleção Sexual, as libélulas têm sido amplamente estudadas devido à grande variedade de padrões comportamentais, de coloração e táticas reprodutivas. Como forma de demonstrar táticas reprodutivas adotadas por duas espécies de libélulas, esta dissertação teve como objetivos principais: i) investigar o papel de traços secundários como a coloração corporal na competição intra-sexual de uma espécie territorial e ii) analisar se os traços corporais como tamanho e morfologia das asas predizem a tática de acasalamento adotada por machos de uma espécie nãoterritorial. Sugere-se que a coloração corporal pode predizer o resultado de lutas e também se correlacionar positivamente com a condição física dos machos territoriais de Tigriagrion aurantinigrum. Ademais, traços corporais como o tamanho e a morfologia das asas influenciam na tática reprodutiva utilizada por machos não-territoriais de Epipleoneura williamsoni. Portanto, com os resultados obtidos, conclui-se que a variação nos sinais visuais exerce um papel essencial na comunicação animal e na resolução de conflitos, indicando ainda que pode haver uma sinalização da condição física dos machos. Além disso, os resultados mostraram evidências em como diferentes táticas reprodutivas se relacionam com traços corporais como agilidade e tamanho corporal, os quais podem influenciar no sucesso reprodutivo dos indivíduos. / In studies concerning Sexual Selection theory, dragonflies and damselflies have been well studied due to their wide range of behavioral, color and reproductive tactics patterns. To demonstrate reproductive tactics adopted by two damselfly species, this study aimed to: i) investigate the role of secondary traits such as body coloration in intrasexual competition of a territorial species and ii) analyze if body traits such as size and wing morphology predicts the adopted tactic by non-territorial males. It is suggested that body coloration can predict the fight outcome and also positively correlates with males physical condition in territorial males of Tigriagrion aurantinigrum and body traits such as body size and wing morphology influence the reproductive tactic adopted by non-territorial males of Epipleoneura williamsoni. Therefore, with these results, it is concluded that the visual signalling variation plays an important role on the animal comunication and conflict resolution, which also may indicate that there is a signalling on the males physical condition. Furthermore, the results showed evidence in how different reproductive tactics are related to body traits such as agility and size, which can influence on individuals reproductive success.

L'utilisation massive des nanomatériaux pose de réels enjeux sanitaires et environnementaux. C'est pourquoi ils sont désormais soumis à une réglementation qui prévoit une traçabilité de ceux-ci depuis leur fabrication jusqu'à leur distribution et l'établissement d'une fiche d'identité de la substance (composition, taille, état d'agglomération, forme, etc.). Une routine de caractérisation de nanoparticules en suspension a ainsi été développée. La Microscopie Électronique en Transmission (MET) a permis d'établir une majorité des paramètres de la fiche d'identité, en combinant à la fois imagerie et spectroscopie (analyses chimiques). La préparation, dont dépendra la qualité des observations, nécessite un développement pour chaque matériau analysé. Pour cela, trois techniques ont été mises au point : le dépôt en voie sèche qui permet une observation directe et simple, la cryogénie qui permet de fixer l'état de la suspension et l'in-situ liquide qui permet d'observer directement la suspension sans changement d'état. Les analyses MET étant locales, une comparaison avec des techniques indirectes a été effectuée par Diffusion Statique (MALS) et Dynamique (DLS) de la Lumière avec et sans fractionnement par couplage flux-force (FFF). Deux matériaux modèles ont été choisis. Le premier est une nanoémulsion de lipides stabilisés par des surfactants, servant de vecteurs à des principes actifs. Une étude de vieillissement par interaction avec des protéines a été menée et de légères variations de taille ont été obtenues. Le second matériau sélectionné est une poudre de nanoparticules de dioxyde de titane, remises en suspension, utilisée dans les crèmes solaires en tant que filtres UV. Ces particules ont été observées avant et après passage en enceinte climatique afin d'observer les effets des rayons UV sur celles-ci. Ceci a confirmé la stabilité des particules. Les protocoles de caractérisation développés au cours de cette thèse peuvent ainsi servir de supports à l'étude d'autres nanoparticules en suspension. / The extensive use of nanomaterials has raised awareness about health issues and their fate in the environment. That is why they are now subject to regulation that has imposed their traceability from their manufacturing to their distribution as the establishment of their characteristics (chemical composition, size, agglomeration state, shape ...). A characterization routine for nanoparticles in suspension was developed. Transmission Electron Microscopy (TEM) fulfills most of the criteria cited before by combining imaging and spectroscopy techniques. Three sample preparation methods were optimized to ensure high quality results : a dry process, rapid freezing to vitrify the sample and the use of an textit{in-situ} liquid TEM holder to prevent any preparation artefact (no phase change). To obtain quantitative analysis, a comparison was made between Dynamic Light Scattering (DLS), Multi-Angle Light Scattering (MALS), with and without a fractionation system (AF4), and TEM. To support this work, two nanomaterials were analyzed. The first one is a nanoemulsion composed of lipid nanoparticles stabilized by surfactants used as nanocarriers for drug delivery. Their stability after protein interaction was investigate and some size variations were observed. The second material is a powder composed of titanium dioxide nanoparticles used as UV filters in sunscreens. These nanoparticles were analyzed before and after interaction with UV radiation in a climatic chamber to confirm their stability. The different protocols developed in this PhD may be used for the analysis of other nanomaterials.

O comportamento animal associado a características morfológicas fornece evidências para um melhor entendimento de como o comportamento sexual tem evoluído, e como os organismos podem maximizar seu sucesso reprodutivo. Fatores como tamanho, reservas de energia e outros caracteres sexuais como a coloração são essenciais para o melhor desempenho em relação a outros indivíduos da mesma espécie. Estes podem transmitir informação da qualidade do macho para outros machos co-específicos como também para às fêmeas. Esta qualidade, guarda relação com a condição física (reservas de energia) que possuem, e é necessária para ter sucesso na reprodução. Sendo a reprodução uma das mais custosas em términos energéticos em comparação a outras atividades, é de se esperar que os animais invistam a maioria das reservas no comportamento reprodutivo, o qual influencia no tipo de estratégia que eles adotam e à duração em tempo das interações relacionadas a reprodução, entre outras. Portanto indivíduos com características melhor desenvolvidas ou com boa condição física, terão uma vantagem na reprodução que os outros indivíduos da comunidade. Zenithoptera lanei é uma espécie neotropical presente no Brasil, da qual se tem poucos estudos sobre sua ecologia comportamental, sendo uns dos mais importante o realizado por Guillermo-Ferreira no 2015, para descrever as estruturas que conformam esta pruinosidade e sua função na comunicação intraespecífica. Neste estudo, descrevemos o comportamento sexual de Z. lanei (Libellulidae), com a hipótese que nesta espécie apresentam machos territoriais, e que a coloração de suas asas, o tamanho corporal e a reserva de energia (gordura) devem desempenham um papel importante na condição territorial. Assim, os machos com maior quantidade de energia e maior tamanho deveriam ganhar disputas, defender territórios e, portanto, manter a condição territorial. Além, avaliamos também se essa condição de territorialidade poderia influenciar o tempo de duração das cópulas e a oviposição pelas fêmeas. Os resultados mostraram que machos são territoriais, e esta territorialidade está relacionada com a condição física e tamanho. Sendo que, machos com maior tamanho corporal e maior quantidade de reservas de energia ganharam mais disputas e mantiveram um território. Apesar dos machos serem territoriais, não houve diferença entre a duração do tempo das interações reprodutivas para machos vencedores em comparação aos machos perdedores, indicando que o tempo de duração das interações reprodutivas não são influenciadas pela condição de territorialidade do macho. / Animal behavior associated with morphological characteristics supplies evidence for a better understanding of how sexual behavior has evolved, and how organisms can maximize their reproductive success. Factors such as size, fat reserves and other sexual characters such as coloration are essential to individual better performance in relation to conspecifics. These factors? Can bring information of the male quality to other conspecifics and females. This quality keeps relation with the physical condition (energy reserves) that they have which is required to succeed in breeding, as reproduction is one of the most expensive activity in energy cost in relation to other activities. The reproductive behavior is related to the individual fat reserves that influences, among other factors, in the condition that they adopt and to the duration in time of the related interactions to reproduction. Therefore, individuals with more developed characteristics or with better physical conditions will have an advantage in the reproduction comparing with other individuals of the community. The dragonfly Zenithoptera lanei is a Neotropical species present in Brazil, only studied so far by Guillermo-Ferreira in 2015, when structures that conform this pruinosity and his function in the intraspecific communication were described. In this study, describe the sexual behavior of Z. lanei (Libellulidae). Was hypothesized that in this species males present territorial behavior, and that the coloration of wings, body size and the energy reserves (fat) may play an important role in territorial condition and reproductive success. Thus, males with higher quantity of energy and larger size should win more disputes, defend territories and, therefore, maintain the territorial condition. In addition, was also assessed whether this condition of territoriality may influence the duration of the copulation and oviposition by females. The results showed that males are territorial, and its territoriality keeps relation with size and the physical condition. In other words, males with larger body and higher energy reserves have won more disputes and maintained a territory. Although males were territorial, there was no difference between the duration of reproductive interactions, winning males and losers, thus indicating that the reproductive interactions are not influenced by the condition of territoriality of the male.

O mamão (Carica papaya L.) cv. \"Sunrise Solo\" é um fruto que apresenta mudança gradual e desuniforme da cor da casca, que vai de verde para amarela. Isso faz com que a metodologia instrumental para avaliação da cor, por meio de um colorímetro, seja subjetiva, devido ao número de pontos observados, bem como às localizações deles no fruto. Como alternativa, foi proposta a utilização de imagens digitalizadas de toda região da casca do fruto, obtidas por meio de um scanner de mesa. Para avaliar a precisão desses métodos, foi conduzido um experimento com 20 repetições. Cada repetição era constituída de um fruto de mamoeiro cv. \"Sunrise Solo\", mantido sob temperatura e umidade relativa controladas. A cor da casca dos frutos foi avaliada, diariamente, utilizando um colorímetro e um scanner. Com o scanner, foram digitalizadas as duas faces do fruto e, com o colorímetro, foram observados quatro pontos equidistantes, na região equatorial do mesmo. Como a avaliação para cada fruto foi feita ao longo do tempo, os dados são classificados como longitudinais. Assim, utilizaram-se modelos lineares de efeitos mistos para estudar o comportamento da tonalidade média, pois essa técnica permite o uso de diferentes estruturas de variâncias e covariâncias para as matrizes dos efeitos aleatórios e dos erros. O processo de seleção do modelo foi realizado por meio do teste da razão de verossimilhanças e dos critérios de informação AIC e BIC, resultando no mesmo preditor linear e matrizes de variâncias e covariâncias para ambas as metodologias de quantificação da cor. O modelo final apresentou um preditor linear quadrático com efeitos aleatórios para o intercepto e para os termos linear e quadrático com matriz de variâncias e covariâncias dos efeitos aleatórios não estruturada e componentes de variância com heterocedasticidade para os erros. A utilização do scanner revelou dois grupos de maturação fisiológica distintos, que podem estar relacionados ao ponto de colheita do fruto, fato que não ficou evidente ao utilizar um colorímetro. De forma geral, o uso de um scanner possibilitou obter uma avaliação precisa da maturação do fruto, além de ser mais consistentes e eficiente do que o uso de um colorímetro para estudar a tonalidade média da casca de frutos que apresentam coloração desuniforme. / Papayas (Carica papaya L.) of \"Sunrise solo\" variety are fruits that present gradual and uneven changes in the peel color, which goes from green to yellow. As a consequence, when using a colorimeter to quantify their color, the results are subjective because of the number of observed points, as well as because of their position on the fruit. A proposed alternative was to use scanned images of the whole fruit peel to quantify color. To assess the precision of these methods, an experiment with 20 replicates was carried out. Each replicate consisted of a papaya fruit, kept under controlled temperature and relative humidity. The fruits\' peel colors were assessed, daily, using a colorimeter and a scanner. With the scanner, both sides of the fruit were scanned and, with the colorimeter, four equidistant points at the equatorial region of the fruit were observed. As the assessment was made through time for a same fruit, the data are classified as longitudinal. Therefore, linear mixed effect models were used to study the behavior of the average fruit color tonality through time, as this technique allows usage of different random effects and error covariance structures. Model selection was made using likelihood-ratio tests and the Akaike and Bayesian information criteria, which resulted in the selection of the same linear predictor and covariance matrices for both color quantification methods. The final model presented a quadractic linear predictor with random effects for the intercept, linear and quadractic terms with an unstructured variance-covariance matrix for the random effects and a variance components with heterogeneity matrix for the residuals. The use of a scanner revealed two distinct phisiological maturation groups, which may be related to the harvesting time. This was not observed when using a colorimeter. In general, using a scanner made possible to obtain more consistent observations, which makes it a more efficient methodology to study the average fruit peel color tonality.