α-Factor receptors from Saccharomyces cerevisiae are G-protein-coupled receptors containing seven transmembrane segments. The ability of α-factor receptors to form oligomeric complexes with each other and with other proteins was investigated. Both in vivo and in vitroevidence was obtained that suggests homo-oligomerization of receptors in the plasma membrane. When the membranes from cells coexpressing two differentially-tagged receptors were solubilized with detergent and subjected to immunoprecipitation, the antibodies specific for either epitope tag resulted in precipitation of both tagged species. Treatment of cultures with α-factor had little effect on the extent of oligomerization as judged by the sedimentation behavior of the receptor complexes and by the efficiency of coimmunoprecipitation. The ability of receptor complexes to undergo ligand-mediated endocytosis was evaluated by using membrane fractionation and fluorescence microscopy. Mutant receptors that fail to bind α-factor (Ste2-S184R) or lack the endocytosis signal (Ste2-T326) became competent for ligand-mediated endocytosis when they were expressed in cells containing wild-type receptors. Coimmunoprecipitation experiments indicated that the C-terminal cytoplasmic domain and intermolecular disulfide bonds were unnecessary for oligomer formation. Therefore, α-factor receptors form homo-oligomers and that these complexes are subject to ligand-mediated endocytosis. A crosslinking and immunoprecipitation strategy was used to capture and characterize the transient complexes that contain the α-factor receptor Ste2. Tagged receptors were crosslinked to form at least three high molecular weight complexes and the complexes were immunoprecipitated with antibodies against the tag. Western blotting analysis of the precipitated material revealed the presence of β and γ subunits of the heterotrimeric G protein, Ste4 and Stel8. Similar results were obtained when the cultures had been treated with α-factor prior to analysis. A truncated receptor missing most of the cytoplasmic C-terminal tail was also active in binding Ste4. Overall, these results constitute the first biochemical evidence for a physical association between the α-factor receptor and its cognate G-protein. Endocytic signals in the C-terminal tail (residues 297-431) of the α-factor receptor were analyzed. One signaling element, SINNDAKSS, (residues 331-339) is known to be sufficient (but not necessary) for endocytosis. Internal deletions of the STE2 gene were constructed that remove sequences encoding SINNDAKSS and selected regions of the C-terminal tail. Strains containing these alelles were then assayed for endocytosis in the presence and absence of α-factor. Residues from 360 to 431 were sufficient to mediate both constitutive and ligand-mediated endocytosis of the receptor even though 63 residues including the SINNDAKSS motif had been removed. Structural features of this region that were investigated further were the highly-ubiquitinated Lys374, the neighboring Lys387, and the GPFAD motif (residues 392-396). Lys374 and Lys387 were unnecessary for the element to promote exit from the plasma membrane; however, Lys374 may play some role in intracellular trafficking. The GPFAD motif was not sufficient to promote endocytosis, since the residues 360-399 provided no detectable endocytic activity. Overall, these results suggest that a new region in the C-terminal of the α-factor receptor, redundant with the SINNDAKSS motif, is sufficient to mediate the constitutive endocytosis as well as the ligand-mediated endocytosis of the receptor.

A wireless body network with sensors and actuators is a topical subject in current situation, because the healthcare services cannot meet peoples requirements for personal health-care. Such a network can be used to monitor the health status of e.g. elderly people and provide a drug delivery without external human interaction. In this project we will implement a prototype of a distributed system of sensors and actuator using the human body as a transmission line for communication purposes (Capacitive Body-coupled Communication), as a solution for the problem. Similar systems have been implemented earlier, using radio-based wireless communication which consumes more power and have critical security issues, compared to capacitive body-coupled communication. This document describes how the system is implemented with focus on robust gathering of sensor data from several sensors from a single node using capacitive body-coupled communication and an actuator control with user interaction.

Cette thèse est consacrée à l’étude mathématiques et numérique d’un problème physique issu de la volcanologie. On s’intéresse à la modélisation polydisperse de croissance de bulles par exsolution, décompression et coalescence. Un modèle de croissance polydisperse a été proposé dans la litérature, mais ne prenait en compte que le volume des bulles, ce qui restreint le domaine d’application car la croissance par exsolution dépend également de la masse d’eau présente dans la bulle. Pour améliorer ce modèle, nous sommes parti d’une description monodisperse adimensionnelle de la croissance d’une bulle par décompression et exsolution, donnée par le couplage de deux EDO et une EDP. Un code numérique est proposé pour résoudre le problème monodisperse et est actuellement utilisé. Après avoir validé numériquement ce code et considéré plusieurs cas limites, nous avons étudié les solutions du problème et défini une approximation du flux qui nous permet de découpler le système d’équations. Ensuite, nous avons étendu le modèle polydisperse de une à deux dimensions. Une résolution de la coalescence est proposée et couplée avec le modèle de croissance polydisperse. La résolution de la coalescence est confrontée à d’autres schémas numériques en une et deux dimensions afin de valider le schéma numérique proposé. Les premiers test numériques appliqués au problème physique donnent de bon résultats. / This thesis is devoted to mathematical and numerical study of a physical problem coming from volcanology. We look at the polydisperse modeling of bubbles growth by exsolution, decompression and coalescence. A polydisperse growth model has been proposed in literature, but it takes into accountonly the volume of bubbles, which restrict the application field, because growth by exsolution also depends on the water mass in the bubbles. In order to upgrade this model, we start with a non-dimensional monodisperse description of the bubble growth by decompression and exsolution, given by a coupled ODE system and a PDE. A numerical code is proposed to solve the monodisperse problem and is currently used. After validating this code numerically and considering several limit cases, we studied the solutions of the system and defined a flux approximation to decouple the equations system. Next, we extend the polydispers model from one to two dimensions, the volume and the water mass of bubbles. A resolution of coalescence is proposed and coupled with the polydisperse growth model. The resolution of coalescence is confronted with others numericals schemes in one and two dimensions in order to validate the proposed numerical scheme. The first numerical tests applied to a physical problem give good results.

L'entrée dans la vie adulte est un processus plus ou moins étalé dans le temps, au cours duquel les jeunes connaissent différentes transitions : du départ de chez les parents à un logement indépendant, de la fin des études à l'insertion sur le marché du travail, du célibat à une vie en couple. Dans le contexte d'une société massivement scolarisée les transitions entre ces événements ont été modifiées. La majorité des étudiants acquiert ainsi leur autonomie résidentielle tout en étant pour une large partie d'entre eux encore dépendants financièrement de leurs parents. L'insertion sur le marché du travail de manière stable se fait à un âge plus tardif. Pour autant de plus en plus d'étudiants exercent une activité rémunérée en parallèle de leurs études. L'installation conjugale se décide au cours des études pour une minorité d'étudiants, mais pour la majorité d'entre eux ce moment est reporté après une insertion sur le marché du travail pérenne. Tout au long de ce travail ces différents événements ont été analysés pour mieux saisir ce processus complexe d'entrée dans la vie adulte. Les données sur lesquelles s'appuie cette thèse sont de type longitudinales rétrospectives, mêlant à la fois une approche quantitative (Panel DEP 1989) et une approche qualitative (53 entretiens). Ces données nous ont permis d'élaborer une typologie des modes d'entrée dans la vie adulte et de mettre en lumière les interactions entre les différentes sphères (études, emploi, décohabitation, mise en couple, naissance des enfants). / The transition into adulthood is a process spread in time. It starts with people moving from their parents' homes, graduating and integrating the labour market, and moving into a coupled life. In a society with rising educational achievements, the timing of these life transitions has changed. Most students move into independent housing arrangements during their studies even though the majority are still financially dependent on parents. Full integration into the labour market happens at a later stage and most students have temporary jobs while studying. Moreover, most students do not settle down into a coupled life until the end of their education with few of them getting into couples during this phase. Throughout this thesis, these different events are studied in order to explore the complex transmissions into adulthood. This work relies on retrospective longitudinal data combining both the quantitative DEP Panel of 1989 and additional qualitative data based on 53 interviews. These data were used to identify a typology of modes of transition into adulthood and to shed light on the interactions between the different spheres: Study, employment, cohabitation, and the birth of children.

Dans le contexte du calcul scientique, l'équilibrage de la charge est un problème crucial qui conditionne la performance des simulations numériques parallèles. L'objectif est de répartir la charge de travail entre un nombre de processeurs donné, afin de minimiser le temps global d'exécution. Une stratégie populaire pour résoudre ce problème consiste à modéliser la simulation à l'aide d'un graphe et à appliquer des algorithmes de partitionnement. En outre, les simulations numériques tendent à se complexifier, notamment en mixant plusieurs codes représentant des physiques différentes ou des échelles différentes. On parle alors de couplage de codes multi-physiques ou multi-échelles. Dans ce contexte, le problème de l'équilibrage de charge devient également plus difficile, car il ne s'agit plus d'équilibrer chacun des codes séparément, mais l'ensemble de ces codes pris dans leur globalité. Dans ce travail, on propose de resoudre ce problème en utilisant le modèle de partitionnement à sommets fixes qui pourrait représenter efficacement les contraintes supplémentaires imposées par les codes couplés (co-partitionnement). Nous avons donc développé un algorithme direct de partitionnement de graphe qui gère des sommets fixes. L'algorithme a été implémenté dans le partitionneur Scotch et une série d'expériences ont été menées sur la collection des graphes DIMACS. Ensuite nous avons proposé trois algorithmes de co-partitionnement qui respectent les contraintes issues des codes couplés respectifs. Nous avons egalement validé nos algorithmes par une étude expérimentale en comparant nos méthodes aux strategies actuelles sur des cas artificiels ainsi que sur des codes réels couplés. / Load balancing is an important step conditioning the performance of parallel applications. The goal is to distribute roughly equal amounts of computational load across a number of processors, while minimising interprocessor communication. A common approach to model the problem is based on graph structures and graph partitioning algorithms. Moreover, new challenges involve the simulation of more complex physical phenomena, where different parts of the computational domain exhibit different physical behavior. Such simulations follow the paradigm of multi-physics or multi-scale modeling approaches. Combining such different models in massively parallel computations is still a challenge to reach high performance. Additionally, traditional load balancing algorithms are often inadequate, and more sophisticated solutions should be explored. In this thesis, we propose new graph partitioning algorithms that balance the load of such simulations, refered to as co-partitioning. We formulate this problem with the use of graph partitioning with initially fixed vertices which we believe represents efficiently the additional constraints of coupled simulations. We have therefore developed a direct algorithm for graph partitioning that manages successfully problems with fixed vertices. The algorithm is implemented inside Scotch partitioner and a series of experiments were carried out on the DIMACS graph collection. Moreover we proposed three copartitioning algorithms that respect the constraints of the respective coupled codes. We finally validated our algorithms by an experimental study comparing our methods with current strategies on artificial cases and on real-life coupled simulations.

abstract: In the face of increasing anthropogenic threats to marine systems, marine reserves have become a popular tool to promote sustainable fisheries management and protect marine biodiversity. However, the governance structures that determine marine reserve success are not well understood. The response of resource users to reserve establishment, as well as the socioeconomic, institutional, and political contexts in which they occur, are rarely considered during reserve implementation. I use the Coupled Infrastructure Systems (CIS) framework to better understand the interdependencies between social, economic, natural, and institutional processes affecting reserve implementation and performance efficacy in the Gulf of California, Mexico. I used a combination of interviews, qualitative case study comparisons, and systematic conservation planning tools to evaluate the role of different infrastructures, institutions, and governance for marine reserve efficacy in the Gulf of California, Mexico. At a local scale, I assessed stakeholder perceptions, preferences, and knowledge on reserves in the Midriff Islands sub-region of the Gulf. My results show differences in fisher perceptions about the use of reserves for biodiversity conservation and fisheries management, misconceptions about their location, and non-compliance behavior problems. At the regional scale, I explored the trajectories of reserve implementation and performance. I show that capacity-building programs and effective collaboration between non-profit organizations, environmental, fisheries, and other government authorities are essential to coordinate efforts leading to the provisioning of infrastructure that enables effective marine reserves. Furthermore, these programs help facilitate the incorporation of fishers into diversified management and economic activities. Infrastructure provision tradeoffs should be carefully balanced for designing scientifically-sound reserves that can achieve fisheries recovery objectives and incorporating stakeholder engagement processes during the planning phase that allow fishers to include their preferences in a way that complements proposed reserve network solutions. Overall, my results highlight the importance of multiple infrastructures in understanding the dynamics of interacting action situations at various stages of marine reserve implementation and operation. I identify strengths and weaknesses within marine reserve systems that help understand what combinations of infrastructures can be influenced to increase marine reserve effectiveness and robustness to internal and external challenges, as well as delivering benefits for both nature and people. / Dissertation/Thesis / Doctoral Dissertation Environmental and Resource Management 2017

Fundação de Amparo a Pesquisa no Estado do Rio Grande do Sul / In this work we propose a discrete predator-prey model with the purpose of analyzing the spatio-temporal dynamics of herbivorous and their predators. For that, we explicitly consider the dispersion of both species through Coupled Map Lattice models, that is, systems of difference equations coupled by dispersal. We suppose that the prey population presents density-dependent growth and predators, Holling type II functional response. In order to analyze the effects of prey-taxis showed by predators, which means, that predators direct their movement to regions of high prey densities, we computationally implemented our model for different movement schemes: difusion for both species, immobile prey and taxis for predators and, difusion for prey and taxis for predators. We conclude that the dispersal behavior of predators and preys plays a crucial role on their spatio-temporal dynamics and hence cannot be omitted when modeling predator-prey interactions. / Neste trabalho construímos um modelo presa-predador discreto com objetivo de analisar a dinâmica espaço-temporal de insetos herbívoros e seus predadores. Para tal, consideramos explicitamente a dispersão de ambas as espécies através de modelos de Rede de Mapas Acoplados, isto é, sistemas de equações a diferenças acopladas pela dispersão. Consideramos que as presas apresentam crescimento dependente da densidade e os predadores, resposta funcional Holling do tipo II. Para analisar os efeitos da movimentação de taxia dos predadores, isto é, o movimento direcionado às regiões de maiores densidades de presas, implementamos computacionalmente o modelo para diferentes esquemas de movimentação: difusão para ambas as espécies, presas imóveis e taxia para predadores e difusão para presas e taxia para predadores. Concluímos que o comportamento de movimentação de presas e predadores tem um papel relevante na sua dinâmica espaço-temporal e não pode ser ignorado na modelagem destes sistemas.

Submitted by JOÃO MANOEL SORIANO PITOT null (tribalista22@hotmail.com) on 2017-08-31T13:05:34Z No. of bitstreams: 1 Tese Ficha.pdf: 737367 bytes, checksum: e2b1a948e44236ba2cef5484c4761cd5 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-09-01T13:38:31Z (GMT) No. of bitstreams: 1 pitot_jms_dr_sjrp.pdf: 737367 bytes, checksum: e2b1a948e44236ba2cef5484c4761cd5 (MD5) / Made available in DSpace on 2017-09-01T13:38:31Z (GMT). No. of bitstreams: 1 pitot_jms_dr_sjrp.pdf: 737367 bytes, checksum: e2b1a948e44236ba2cef5484c4761cd5 (MD5) Previous issue date: 2017-08-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Neste trabalho estudamos o problema de controlabilidade exata na fronteira para um sistema de equações de onda acopladas em paralelo, em domínios suave por partes do plano, sob ação de controle do tipo Neuman. Utilizando o método empregado por D. L. Russell em [33] obtemos controlabilidade em tempo suficientemente grande para dados iniciais de energia finita e controle de quadrado integrável. A fim de obter tempo de controle próximo a valores ótimos, procedemos como em [21]: estendemos a solução do problema de Cauchy para tempo complexo e provamos que o operador solução associado ao problema de Cauchy é compacto e depende analiticamente do tempo num setor adequado do plano complexo. Utilizando decaimento local de energia, analiticidade e compacidade do operador solução obtemos o resultado desejado. / In this work we study the problem of exact controllability on the boundary for a system of wave equations coupled in parallel, in piecewise smooth domains of the plane, under the action of control of Neuman type. Using the method employed by D. L. Russell in [33] we obtain controllability in time sufficiently large for initial data of finite energy and square integrable control. In order to obtain control time close to optimal values, we proceed as in [21]: we extend the solution of the Cauchy problem to complex time and we prove that the solution operator associated with the Cauchy problem is compact and depends analytically of the time in an appropriate sector of the complex plane. Using local decay of energy, analyticity and compactness of the solution operator we obtain the desired result.

Made available in DSpace on 2014-12-17T14:09:16Z (GMT). No. of bitstreams: 1 JoseCSJ_TESE_PARCIAL.pdf: 3198681 bytes, checksum: 3124bf4fcf475e3c972bb5266fef2405 (MD5) Previous issue date: 2013-02-20 / Steam injection is a method usually applied to very viscous oils and consists of injecting heat to reduce the viscosity and, therefore, increase the oil mobility, improving the oil production. For designing a steam injection project it is necessary to have a reservoir simulation in order to define the various parameters necessary for an efficient heat reservoir management, and with this, improve the recovery factor of the reservoir. The purpose of this work is to show the influence of the coupled wellbore/reservoir on the thermal simulation of reservoirs under cyclic steam stimulation. In this study, the methodology used in the solution of the problem involved the development of a wellbore model for the integration of steam flow model in injection wellbores, VapMec, and a blackoil reservoir model for the injection of cyclic steam in oil reservoirs. Thus, case studies were developed for shallow and deep reservoirs, whereas the usual configurations of injector well existing in the oil industry, i.e., conventional tubing without packer, conventional tubing with packer and insulated tubing with packer. A comparative study of the injection and production parameters was performed, always considering the same operational conditions, for the two simulation models, non-coupled and a coupled model. It was observed that the results are very similar for the specified well injection rate, whereas significant differences for the specified well pressure. Finally, on the basis of computational experiments, it was concluded that the influence of the coupled wellbore/reservoir in thermal simulations using cyclic steam injection as an enhanced oil recovery method is greater for the specified well pressure, while for the specified well injection rate, the steam flow model for the injector well and the reservoir may be simulated in a non- coupled way / A inje??o de vapor ? um m?todo aplicado geralmente em ?leos muito viscosos e consiste em injetar calor para reduzir a viscosidade e, portanto, aumentar a mobilidade do ?leo, resultando em incremento na produ??o dos po?os. Para o planejamento de um projeto de inje??o de vapor ? necess?rio efetuar um estudo de reservat?rio com o objetivo de se definir os v?rios par?metros necess?rios para um eficiente gerenciamento de calor no meio poroso e, com isto, melhorar o fator de recupera??o do reservat?rio. Neste estudo, para o sistema de inje??o, representado pelo po?o injetor, ? normalmente adotado um modelo padr?o em todos os casos estudados, sendo desta forma, a integra??o entre o po?o injetor e o reservat?rio, realizada de forma bastante simplificada. Este trabalho tem como objetivo mostrar a influ?ncia do acoplamento do po?o injetor nas simula??es t?rmicas de reservat?rios submetidos ? inje??o c?clica de vapor. Neste estudo, a metodologia utilizada na solu??o do problema envolveu o desenvolvimento de um modelo de po?o para a integra??o do modelo de escoamento de vapor em po?os de petr?leo, VapMec, e o modelo de reservat?rio tipo beta para a inje??o c?clica de vapor em reservat?rios de petr?leo. Assim, desenvolveram-se estudos de caso para reservat?rios rasos e profundos, considerando as principais configura??es de po?o injetor existentes na ind?stria de petr?leo, ou seja, coluna convencional sem packer, coluna convencional com packer e coluna isolada com packer. Foi realizado um estudo comparativo dos par?metros de inje??o e produ??o obtidos na simula??o, considerando sempre as mesmas condi??es de opera??o, para os dois modelos de simula??o, sendo um modelo n?o acoplado e o outro modelo acoplado. Observou-se que os resultados entre os modelos s?o bastante similares para a situa??o de vaz?o de inje??o igual ? vaz?o especificada, tendo sido encontrado diferen?as significativas na situa??o em que a press?o de inje??o ? igual ? press?o especificada. Finalmente, com base nos experimentos computacionais, foi poss?vel concluir que a influ?ncia do acoplamento do po?o injetor nos estudos de reservat?rios que utilizam a inje??o c?clica de vapor como m?todo especial de recupera??o ? maior para a condi??o de press?o especificada, sendo que para a condi??o de vaz?o especificada, o modelo de escoamento no po?o injetor e o modelo do reservat?rio podem ser simulados de forma n?o integrada

abstract: Consideration of both biological and human-use dynamics in coupled social-ecological systems is essential for the success of interventions such as marine reserves. As purely human institutions, marine reserves have no direct effects on ecological systems. Consequently, the success of a marine reserve depends on managers` ability to alter human behavior in the direction and magnitude that supports reserve objectives. Further, a marine reserve is just one component in a larger coupled social-ecological system. The social, economic, political, and biological landscape all determine the social acceptability of a reserve, conflicts that arise, how the reserve interacts with existing fisheries management, accuracy of reserve monitoring, and whether the reserve is ultimately able to meet conservation and fishery enhancement goals. Just as the social-ecological landscape is critical at all stages for marine reserve, from initial establishment to maintenance, the reserve in turn interacts with biological and human use dynamics beyond its borders. Those interactions can lead to the failure of a reserve to meet management goals, or compromise management goals outside the reserve. I use a bio-economic model of a fishery in a spatially patchy environment to demonstrate how the pre-reserve fisheries management strategy determines the pattern of fishing effort displacement once the reserve is established, and discuss the social, political, and biological consequences of different patterns for the reserve and the fishery. Using a stochastic bio-economic model, I demonstrate how biological and human use connectivity can confound the accurate detection of reserve effects by violating assumptions in the quasi-experimental framework. Finally, I examine data on recreational fishing site selection to investigate changes in response to the announcement of enforcement of a marine reserve in the Gulf of California, Mexico. I generate a scale of fines that would fully or partially protect the reserve, providing a data-driven way for managers to balance biological and socio-economic goals. I suggest that natural resource managers consider human use dynamics with the same frequency, rigor, and tools as they do biological stocks. / Dissertation/Thesis / Ph.D. Applied Biological Sciences 2014