Tuna-dolphin-bird feeding assemblages are unique to the Eastern Tropical Pacific Ocean (ETP). These multiple species groups are believed to forage together in response to the physical properties of the near surface ocean as these constrain the distribution of prey. In the Galapagos Marine Reserve (GMR), intra-annual and interannual changes affect the properties of the water column, inducing mesoscale and fine scale temporal variability. Four three-week oceanographic surveys took place, in September 2008, April 2009, October 2009, and September 2010, between the coast of Ecuador and the Galapagos Islands and one small boat survey took place in June 2010 within the GMR. Marine mammal surveys were conducted during daylight hours and Conductivity, Temperature, Depth (CTD) sensor casts were taken throughout the survey. Data were analyzed to determine the types of water masses present and the strength and depth of the thermocline layer. These data were compared with the sightings of marine mammals, bird feeding groups, and tuna-dolphin-bird assemblages. Additionally, these data were used to predict where tuna would be likely to associate with dolphin groups. Results show Equatorial Surface Water was the dominant water mass throughout the archipelago, regardless of season or ENSO index. High salinity, cold water west of Isla Isabela indicated topographic upwelling of the Equatorial Undercurrent. Tropical Surface Waters from the Panama Current were detected north of the Equatorial Front to the east of the islands. Obvious changes in the water column properties were observed between El Niño and La Niña events in the GMR. Most mixed groups were sighted west and south of Isla Isabela during the four oceanographic surveys, as well as north and west of Isla San Cristobal in June 2010. Most sightings were in cool, high salinity waters, and high chlorophyll concentrations. There were a greater number of sightings during the April 2009 survey (ENSO-neutral conditions) than during any of the three fall surveys. Additionally, tuna-dolphin-bird groups were more likely to be seen near Isla Isabela, with the majority of them sighted during the April 2009 survey and a few sighted in each of the September 2008 and October 2009 surveys. No tuna-dolphin-bird groups were sighted during the September 2010 surveys. Results show that the presence and location of these multi-species groups may be controlled by the inter-annual cycles, the intra-annual cycles, or a combination of both types of changes seen within the Galapagos.

Thèse (de maîtrise)--Université Laval, 2008. / Bibliogr. Publié aussi en version électronique dans la Collection Mémoires et thèses électroniques.

Th. univ.--Mécanique des solides et des structures--Paris 6, 1995. / Bibliogr., 8 p.

Thèse (M.Sc.)--Université Laval, 2003. / Bibliogr.: f. [84]-89. Publié aussi en version électronique.

Esta tese trata de um estilo de criatividade política quilombola que não circunscreve sua territorialidade com base nos vínculos criados exclusivamente com a terra e com os produtos da terra. O estudo cartografa as modalidades de enfrentamento entre quilombolas, indígenas e “sem terras”, de um lado, com o Estado e seus mediadores, de outro, que decorrem de concepções divergentes acerca do território, da identidade e da composição da vida. O cenário é ambientado no contexto de implementação dos dispositivos de justiça para regularização fundiária do território habitado por famílias quilombolas que vivem na localidade de Júlio Borges, município do Salto do Jacuí, RS. Além dos quilombolas, passaram a residir no território titulado, dois coletivos distintos de indígenas Kaingang e algumas famílias que se apossaram de porções da mesma área de terras em processo de titulação. As formas de convívio entre quilombolas, indígenas e “sem terras” levam-nos a penetrar um mundo marcado pela transformação e pela diferenciação em movimentos sucessivos de devir. Este estilo de relação e de convívio, marcado pelo movimento, desenha modalidades de agenciamento político, cuja potência coloca à prova os dispositivos de organização do território de Júlio Borges operacionalizados pela Política Nacional de Titulação Territorial. A tese, ainda, lança-se à tarefa de dar credibilidade aos enunciados nativos, aos saberes e às técnicas que compõem a cosmopolítica da localidade de Júlio Borges. / This dissertation thesis discusses a style of Quilombola political creativity that does not circumscribe its territoriality based on links created exclusively with the land and the products of the earth. The study maps the modalities of confrontation between Quilombolas, indigenous people and the “landless” groups, and the state and its mediators on one side. On the other side, these confrontations arise from divergent conceptions of territory, identity and composition of life. The study took place in the context of the implementation of justice devices for the regularization of a territory inhabited by Quilombola families in the district of Júlio Borges, in the town of Salto do Jacuí, in Rio Grande do Sul. In addition to the Quilombolas, two separate groups of the Kaingang indigenous tribe and some families who took over portions of the same land undergoing a titling process took up residence in the territory. The kinds of interaction among Quilombolas, indigenous people and the "landless" showed us a world marked by transformation and the differentiation in consecutive movements of being. This way of association and interaction, that is marked by the movement, generates new forms of political mediation, and its power puts the organizational devices of the district of Júlio Borges that are operated by the National Policy on Land Titling to the test. This dissertation thesis aims at giving credibility to the indigenous voice, knowledge and political techniques that make up the cosmopolitics of the district of Júlio Borges.

Esta tese trata de um estilo de criatividade política quilombola que não circunscreve sua territorialidade com base nos vínculos criados exclusivamente com a terra e com os produtos da terra. O estudo cartografa as modalidades de enfrentamento entre quilombolas, indígenas e “sem terras”, de um lado, com o Estado e seus mediadores, de outro, que decorrem de concepções divergentes acerca do território, da identidade e da composição da vida. O cenário é ambientado no contexto de implementação dos dispositivos de justiça para regularização fundiária do território habitado por famílias quilombolas que vivem na localidade de Júlio Borges, município do Salto do Jacuí, RS. Além dos quilombolas, passaram a residir no território titulado, dois coletivos distintos de indígenas Kaingang e algumas famílias que se apossaram de porções da mesma área de terras em processo de titulação. As formas de convívio entre quilombolas, indígenas e “sem terras” levam-nos a penetrar um mundo marcado pela transformação e pela diferenciação em movimentos sucessivos de devir. Este estilo de relação e de convívio, marcado pelo movimento, desenha modalidades de agenciamento político, cuja potência coloca à prova os dispositivos de organização do território de Júlio Borges operacionalizados pela Política Nacional de Titulação Territorial. A tese, ainda, lança-se à tarefa de dar credibilidade aos enunciados nativos, aos saberes e às técnicas que compõem a cosmopolítica da localidade de Júlio Borges. / This dissertation thesis discusses a style of Quilombola political creativity that does not circumscribe its territoriality based on links created exclusively with the land and the products of the earth. The study maps the modalities of confrontation between Quilombolas, indigenous people and the “landless” groups, and the state and its mediators on one side. On the other side, these confrontations arise from divergent conceptions of territory, identity and composition of life. The study took place in the context of the implementation of justice devices for the regularization of a territory inhabited by Quilombola families in the district of Júlio Borges, in the town of Salto do Jacuí, in Rio Grande do Sul. In addition to the Quilombolas, two separate groups of the Kaingang indigenous tribe and some families who took over portions of the same land undergoing a titling process took up residence in the territory. The kinds of interaction among Quilombolas, indigenous people and the "landless" showed us a world marked by transformation and the differentiation in consecutive movements of being. This way of association and interaction, that is marked by the movement, generates new forms of political mediation, and its power puts the organizational devices of the district of Júlio Borges that are operated by the National Policy on Land Titling to the test. This dissertation thesis aims at giving credibility to the indigenous voice, knowledge and political techniques that make up the cosmopolitics of the district of Júlio Borges.

Os processos ecológicos e biogeográficos podem influenciar a composição de espécies em comunidades. A ecologia diz respeito às interações entre espécies e o ambiente enquanto que a biogeografia está relacionada à ocupação dos ambientes pelas espécies pertencentes ao pool regional. A dispersão fornece oportunidade para que as espécies ocupem diferentes ambientes, mas o modo como as espécies interagem entre si e com o ambiente é crucial para a permanência da espécie em uma taxocenose. Dentro desse contexto, este estudo busca entender qual processo, ecológico, histórico ou ambos tem influenciado na estrutura de comunidades de serpentes neotropicais com diferentes tipos de vegetação (áreas florestadas e abertas) usando métodos filogenéticos e fenotípicos. Nós detectamos diferentes padrões de estrutura filogenética nas comunidades da Amazônia (disperso) e dos Campos Sulinos (agregado). No entanto, é possível perceber que comunidades de baixas latitudes tendem a ter estrutura dispersa e comunidades de altas latitudes tendem a ter estrutura agregada. O mesmo padrão foi observado através da análise fenotípica. Além disso, dentre os atributos mensurados o tamanho do corpo é o único que está associado com o tipo de vegetação. Este resultado pode ser uma consequência da maior proporção de espécies arborícolas em taxocenoses florestadas. Essas espécies geralmente são maiores que as terrícolas e as fossoriais. Espécies que utilizam o mesmo habitat são morfologicamente similares. A influência da biogeografia nas comunidades de serpentes é um resultado da distribuição de espécies das três principais linhagens de serpentes da região Neotropical. As espécies de Colubridae e Dipsadinae contribuem mais para a riqueza de espécies em latitudes mais baixas enquanto que Xenodontinae contribui mais nas taxocenoses de altas latitudes. Isto pode explicar o padrão filogenético disperso encontrado nas comunidades de baixa latitude porque estas comunidades são compostas principalmente por espécies de duas linhagens diferentes enquanto que as comunidades de altas latitudes são basicamente compostas por uma única linhagem (o que resultaria em um padrão filogenético agregado). Isso pode explicar também a pequena diferença morfológica entre as comunidades de latitude maior devido à inércia filogenética. Nossos resultados destacam a importância da biogeografia na estruturação de comunidades, corroborando a atual hipótese de que a biogeografia é mais importante para moldar a estrutura de comunidades do que os fatores ecológicos / Both ecological and biogeographical process can influence assemblages\' composition. Ecology may affect interactions among species and their environment while biogeography affects species\' immigration from regional species\' pool. Immigration provides an opportunity to arrive in different localities but the way in which species interact with their environment is a crucial factor in order for a species to thrive. This study aims to understand which processes, ecological, historical or both, have influenced the structure of Neotropical snakes\' assemblages in different vegetation types (forested and open areas), using a phylogenetic and phenotypic approach. We detected different patterns of phylogenetic structure in assemblages from Amazonian rainforest (evenness) and Brazilian Campos Grasslands (clustered) but it is also possible to perceive that assemblages from lower latitudes are evenly structured and assemblages from higher latitudes are clustered, the same being true when we consider their phenotypic structure. Moreover, considering all measured traits body size is the only feature related to vegetation type (open and forested areas). This result may be a consequence of the microhabitat used by a high proportion of species - since arboreal and semi-arboreal species are primarily encountered in forested areas (when compared to open areas), and these species are normally larger than terrestrial and/or fossorial species. Furthermore, species within use the same habitat have similar morphologies. The influence of biogeography in snakes\' assemblages is a result of the species\' distribution from major snakes\' lineages in Neotropics. The lineages Colubridae and Dipsadinae contribute more to assemblages\' richness at lower latitude whereas Xenodontinae contributes more at higher latitudes. This may explain the phylogenetic evenness pattern encountered in assemblages from lower latitudes, since these assemblages are composed mainly by species from two different lineages, while assemblages from higher latitudes are basically composed by one lineage. Although the difference among species\' morphology is smaller in assemblages from higher latitudes due probably to evolutionary constraints. Our results highlight the importance of biogeography in shaping assemblage structure, corroborating the current hypothesis that biogeography is more important in shaping assemblages than ecology

L'assemblage de planches par technique de collage est utilisé pour réaliser des éléments de structure en bois performants. Le collage permet d'obtenir des rigidités et des résistances d'assemblages excellentes. Cependant, ces produits sont souvent polluants à différents degrés et ne permettent pas de s'adapter à une cadence industrielle de fabrication, notamment à cause des temps de pressage. Le niveau de performance s'effondre lorsque l'assemblage par collage est remplacé par des organes de type tige, tels que des pointes, vis ou tourillons en bois, mais ils confèrent un temps de mise en oeuvre instantané. Dans ces types d'assemblages mécaniques, la surface de contact entre les planches n'est plus du tout utilisée pour transmettre des efforts. L'objectif de ce travail est de montrer comment la préparation mécanique des interfaces permet de fortement améliorer le comportement de ces assemblages. La finalité étant de produire des éléments de structure sans composés organiques volatiles (COV), dont la fabrication serait réalisable par un robot industriel, de manière flexible et en utilisant des essences mixtes de bois locaux. La première partie de cette étude est consacrée à répertorier et analyser les différents systèmes reconstitués en bois, ainsi que de montrer comment mener un dimensionnement en tenant compte du caractère imparfait de la connexion. Cette partie montre que la prise en compte du caractère non linéaire des liaisons mécaniques dans les systèmes reconstitués est souvent très imprécise et conduit à des écarts de dimensionnement importants. La deuxième partie décrit une méthodologie pour pallier à ce manque, développée à partir de la modélisation non linéaire d'un élément de construction de type poutre. Cette approche conduit à proposer des raideurs sécantes précises de la liaison permettant le calcul linéaire exact pour les ingénieurs. Cette méthodologie permet de caractériser la raideur d'une liaison par une approche liée au comportement plutôt qu'une approche normative générale. Suite à la mise en évidence de la souplesse de la liaison par organes, une troisième partie expose une réflexion sur l'utilisation des surfaces en contact pour transmettre les efforts. Un traitement mécanique de type rainurage est réalisé à l'interface de contact des pièces à assembler. Il permet de transmettre des efforts de cisaillement et de torsion dans le plan de croisement des planches. Le maintien des éléments en contact est également étudié en développant un principe de vis conique en bois. Pour valider ces principes, des campagnes d'essais sont réalisées afin de mesurer les performances obtenues par le rainurage, la vis conique en bois et leurs utilisations simultanées. La dernière partie est consacrée à la mise en oeuvre de l'assemblage amélioré dans des éléments de structure afin d'en confirmer son potentiel. Le premier élément est une poutre ajourée, le second est un élément de mur contreventant. Les résultats d'essais sont comparés à des modèles numériques incluant le comportement non linéaire des assemblages rainurés vissés. Ces réalisations en grandeurs réelles permettent de valider également leur faisabilité par un robot industriel / Plank bonding connection is used to produce efficient structural timber. The bonding achieves excellent rigidity and connection resistance. However, these products are often pollutants and are incompatible with industrial production rates due to the pressing time. Their performances collapse when the adhesive connection is replaced by rodlike fasteners, such as nails, screws or wooden dowels, but these connections allow a quick assembly. In these assemblies the contact surfaces between planks are not used for transmitting loads. The purpose of this study is to point out how mechanical preparation of the interfaces improves the performance of timber connections. The aim is to produce structural members without volatile organic compounds (VOC), achievable by an industrial robot allowing for flexibility, and using mixed wood local species. The first part of this study consists in identifying and analyzing reconstituted wood systems, as well as showing how to conduct a design by taking into account the partial composite action of connectors. This part explains that the chosen behavior of the mechanical connections in reconstituted systems is frequently very imprecise and leads to significant differences in design. The second part describes a methodology to overcome this lack, developed from the nonlinear modeling of a beamtype component. This approach leads to determine the fastener's secant stiffness for an exact linear calculation for engineers. The outcome of this methodology is the quantification of the fastener's secant stiffness by a related behavior rather than a general normative behavior. Due to the flexibility of members, a third part presents a reflection on the use of the contact surfaces for transmitting loads. The plank interfaces were machined in order to obtain grooves. This binding allows the transmission of shear and torsion forces in the intersection plane of the planks. Maintaining the contact is managed by the development of a wooden conical screw. To validate these principles, test campaigns were carried out to measure the performance of the groove, the wooden conical screw and their simultaneous use. The last section deals with the implementation of the improved assembly in structural members in order to confirm its potential. The first element type is a castellated beams and the second one is a bracing wall. Experimental results are compared with numerical models including the nonlinear grooved screwed connection behavior. Furthermore, these full scale elements validate the feasibility by an industrial robot

Ce travail de recherche présente une stratégie de modélisation et de dimensionnement pour les assemblages boulonnés en milieu aéronautique. Dans le cas du dimensionnement de grandes structures, les bureaux d’étude se servent habituellement de techniques dites de « zoom structural ». Elles permettent de gérer les ressources numériques à disposition, avec des modèles simples et de grande taille à l’échelle globale, et des modèles plus complexes à l’échelle locale. Cette étude s‘insère dans le cadre d’un processus de zoom structural dans lequel les structures étudiées présentent un très grand nombre de fixations. Un premier travail consiste à proposer une modélisation pertinente des fixations à l’échelle globale. Dans une seconde partie, les dispersions de comportement observées dans les fixations boulonnées sont prises en compte par l’utilisation de la théorie des méconnaissances. Une technique de recalage de la modélisation complète est ensuite proposée afin de tirer partie d’éventuels essais réels ou numériques. Enfin, la stratégie proposée est appliquée sur des cas d’assemblages boulonnés de type aéronautique. Les avantages, mais aussi les limites de l’utilisation d’une telle stratégie y sont discutés. / The objective of this work is to develop a modeling strategy for assemblies involving multiple joints in an aeronautical predesign context. In the process of designing large structures, industrial engineers usually get around computational limitations by using submodeling techniques. In order to take into account phenomena which vary during the global representation of the submodeling process, we propose a modeling approach for the scattering of these phenomena based on the Lack-Of-Knowledge (LOK) theory. The LOK model associated with a relevant deterministic joint model is updated based on experimental or simulated data. The proposed strategy is discussed and illustrated by the case of multiple-joint assemblies typical of those used in aeronautics.

Ces travaux de recherche sont réalisés dans le cadre d’une thèse CIFRE en collaboration entre Schlumberger et le LURPA de l’ENS Cachan. Schlumberger est une entreprise de service pétrolier. Elle développe des outils de mesures fonctionnant sous des conditions sévères de température et pression élevées mais aussi des effets dynamiques tels que des accélérations produisant des chocs entre les différentes pièces.L’objectif de la thèse est de déployer de nouvelles règles de cotation, pour des assemblages hyperstatiques déformables, basées sur la méthode CLIC et les normes ISO. La déformation des pièces dépend considérablement des défauts géométriques. Nous avons donc couplé des modèles de chaînes de cotes 3D avec des modèles RdM de type poutre afin d’optimiser les tolérances. Ces modèles doivent permettre la prise en compte des jeux d’assemblage dans les liaisons, la rigidité des pièces et les différents types de contact entre les sous-ensembles des outils étudiés.Ces modèles multi-physiques ont permis de caractériser le comportement mécanique en fonction des écarts géométriques des pièces. Enfin, pour des études plus complexes, des modélisations et simulations éléments finis, sur Abaqus, ont été réalisés puis validées par une campagne expérimentale de comportement au choc. / This research is carried out within a CIFRE doctoral thesis in collaboration between Schlumberger and the LURPA of ENS Cachan. Schlumberger is an oil service company. It develops measurement tools operating under severe conditions of high temperature and pressure but also dynamic effects such as accelerations producing shocks between the different parts.The objective of the thesis is to deploy new dimensioning and tolerancing rules for deformable hyperstatic assemblies, based on the CLIC method and the ISO standards. The deformation of the parts greatly depends on the geometrical defects. We have coupled 3D dimension chains with beam models to optimize tolerances. These models must allow the taking into account of the assembly clearances between parts, their rigidity and the different types of contact between the subassemblies of the studied tools.These multi-physical models allowed to characterize the mechanical behavior as a function of the geometrical deviations of parts. Finally, for more complex studies, finite element models and simulations on Abaqus were carried out and then validated by an experimental campaign of impact behavior.