This practice-as-research project investigates how a piece of site-responsive Installation Art, titled Triple Point Dunnage (exhibited in Royal William Yard, June 2009), can be used to generate knowledge about memory work through experience of site. Working in dialogue with the ideas of Daniel C. Dennett, Lucy Lippard and Gaston Bachelard, I attempted to create a permeable and fluctuating creative setting for the memory work of participants. An approach that used site as a stimulant within a process which also incorporated theoretical themes. During the period of design and construction, I interacted with and recorded interviews with people who had a personal connection with the site or with an interest in how memory works. The final installation presented layers of spoken fragmented content in a dialectic relationship within the installation’s spatial construction. The responses of the installation’s visitors and participants were collated through a response book and interviews. These were analysed in order to discover to what extent, if at all, the properties I had developed and designed into the work had shaped the engagements of the participants. The multi-valented properties of the work generated an array of responses that suggested that the viewers had fashioned their experience by blending the fragmented stories of others with their own personal histories. This engagement resembles Dennett’s concept of “self-narrator” and resonates with Bachelard’s concept of the fusion of physical and psychological space and Lippard’s understanding of place. By exploring memory through site Triple Point Dunnage generated a sense of place that was a fusion of the participants’ responses to the external physical environment and their associative memories stimulated by the affective fragmented properties of the work.

Le système de recombinaison Xer est impliqué dans la monomerisation des réplicons bactériens, comme les plasmides et les chromosomes, dans une grande variété de bactéries. Ce système est un système de recombinaison site-spécifique composé de deux tyrosine recombinases, soit XerC et XerD. Ils agissent ensemble afin de convertir les chromosomes dimériques en monomères en agissant à un site spécifique près du terminus de la réplication, appelé le site dif. Les gènes Xer et leur site d’action sont identifiés dans plusieurs bactéries gram positives et gram négatives. Staphylococcus aureus représente une bactérie gram positive qui contient un système XerCD/dif. Elle est impliqué dans plusieurs maladies humaines, tels que des infections cutanées, des gastroentérites, et le syndrome de choc toxique, pour en nommer quelques unes. Bien que les gènes codant les protéines XerC et XerD ont été identifiés, il y a beaucoup d’inconnu sur leur mode d’action au site dif. Des mutations dans XerC ont été obtenues, mais aucune dans XerD, suggérant que ce gène pourrait être essentiel pour cet organisme. Les études présentées dans ce mémoire ont permis de commencer à mieux caractériser XerD de S. aureus, en séquençant le gène et en faisant des tests de liaison à l’ADN. Elles ont montré que la recombinase XerD se lie au site dif d’Eschericia coli seul et de façon coopérative avec la recombinase XerC d’E. coli. XerD de S. aureus est, aussi, efficace dans la complémentation de XerD muté d’E. coli dans la réaction de recombinaison chromosomique. Cependant, elle ne démontre pas cette même capacité de complémentation lors de la recombinaison plasmidique aux sites cer. / The Xer recombination system is involved in the monomerisation of bacterial replicons, such as plasmids and chromosomes, in a wide variety of bacteria. This system is a site-specific recombination system comprised of two tyrosine recombinases, XerC and XerD, which act in concert to convert dimeric chromosomes to monomers by acting at a specific site near the terminus of replication called the dif site. Xer genes and their site of action have been identified in many gram positive and gram negative bacteria. Staphylococcus aureus represents a gram positive bacterium containing a XerCD/dif system. It is a bacteria implicated in many human diseases, such as skin infections, gastroenteritis and toxic shock syndrome, to name a few. Although the genes encoding the XerC and XerD proteins have been identified, not much is known about their mode of action on the dif site. Mutations in xerC have been obtained, but none in xerD, suggesting that this gene may be essential for this organism. The work presented in this paper has allowed us to better understand the XerD protein of S. aureus, not only in the sequencing of the xerD gene but also in the performing of DNA binding assays. It has been shown that XerD binds to the dif site of E. coli, not only alone but also in cooperativity with E. coli XerC. S. aureus XerD is also capable of complementing the mutated XerD protein in E. coli when it comes to chromosomal recombination. However, it does not demonstrate this same ability to complement XerD regarding recombination at the plasmidic cer sites.

Chez les bactéries à chromosome circulaire, la réplication peut engendrer des dimères que le système de recombinaison site-spécifique dif/Xer résout en monomères afin que la ségrégation des chromosomes fils et la division cellulaire se fassent normalement. Ses composants sont une ou deux tyrosines recombinases de type Xer qui agissent à un site de recombinaison spécifique, dif, avec l’aide de la translocase FtsK qui mobilise l’ADN au septum avant la recombinaison. Ce système a été d’abord identifié et largement caractérisé chez Escherichia coli mais il a également été caractérisé chez de nombreuses bactéries à Gram négatif et positif avec des variantes telles que les systèmes à une seule recombinase comme difSL/XerS chez Streptococcus sp et Lactococcus sp. Des études bio-informatiques ont suggéré l’existence d’autres systèmes à une seule recombinase chez un sous-groupe d’ε-protéobactéries pathogènes, dont Campylobacter jejuni et Helicobacter pylori. Les acteurs de ce nouveau système sont XerH et difH. Dans ce mémoire, les premières recherches in vitro sur ce système sont présentées. La caractérisation de la recombinase XerH de C. jejuni a été entamée à l’aide du séquençage de son gène et de tests de liaison et de clivage de l’ADN. Ces études ont montré que XerH pouvait se lier au site difSL de S. suis de manière non-coopérative : que XerH peut se lier à des demi-sites de difSL mais qu’elle ne pouvait, dans les conditions de l’étude effectuer de clivage sur difSL. Des recherches in silico ont aussi permis de faire des prédictions sur FtsK de C. jejuni. / DNA replication can form dimers in bacteria harboring a circular chromosome. The dif/Xer recombination system resolves monomers them so that chromosome segregation and cell division take place normally. This system is composed of one or two tyrosine recombinases that act at a specific recombination site, dif, with the help of the FtsK translocase that mobilises DNA to the septum before recombination. The Xer system has been first identified and widely characterized in Escherichia coli where XerC and XerD are the recombinases. The system has been found and studied in many other Gram negative and positive bacteria. A different form, carrying a single recombinase acting on an atypical site, has been identified in Streptococci and Lactococci, difSL/XerS. In silico studies suggested the existence of other single recombinase systems in a sub-group of pathogenic ε-proteobacteriasuch as Campylobacter jejuni and Helicobacter pylori. The components of this system were identified as XerH and difH. In this thesis, the first in vitro studies made on this system are presented. The characterization of the XerH recombinase of C. jejuni started with the sequencing of its gene and with the DNA binding and cleavage assays. These studies showed that XerH could bind difSL of S. suis non-cooperatively, that it could bind difSL half-sites and that it was unable to perform cleavage on difSL. Also, in silico comparisons permitted predictions on FtsK of C. jejuni.

Les dimères chromosomiques se produisant lors de la réparation de chromosomes circulaires peuvent être dommageables pour les bactéries en bloquant la ségrégation des chromosomes et le bon déroulement de la division cellulaire. Pour remédier à ce problème, les bactéries utilisent le système Xer de monomérisation des chromosomes. Celui-ci est composé de deux tyrosine recombinases, XerC et XerD, qui vont agir au niveau du site dif et procéder à une recombinaison qui aura pour effet de séparer les deux copies de l’ADN. Le site dif est une séquence d’ADN où deux répétitions inversées imparfaites séparées par six paires de bases permettent la liaison de chacune des recombinases. Cette recombinaison est régulée à l’aide de FtsK, une protéine essentielle de l’appareil de division. Ce système a été étudié en profondeur chez Escherichia coli et a aussi été caractérisée dans une multitude d’espèces variées, par exemple Bacillus subtilis. Mais dans certaines espèces du groupe des Streptococcus, des études ont été en mesure d’identifier une seule recombinase, XerS, agissant au niveau d’un site atypique nommée difSL. Peu de temps après, un second système utilisant une seule recombinase a été identifié chez un groupe des epsilon-protéobactéries. La recombinase fut nommée XerH et le site de recombinaison, plus similaire à difSL qu’au site dif classique, difH. Dans cette thèse, des résultats d’expériences in vitro sur les deux systèmes sont présentés, ainsi que certains résultats in vivo. Il est démontré que XerS est en mesure de se lier de façon coopérative à difSL et que cette liaison est asymétrique, puisque XerS est capable de se lier à la moitié gauche du site prise individuellement mais non à la moitié droite. Le clivage par XerS est aussi asymétrique, étant plus efficace au niveau du brin inférieur. Pour ce qui est de XerH, la liaison à difH est beaucoup moins coopérative et n’a pas la même asymétrie. Par contre, le clivage est asymétrique lui aussi. La comparaison de ces deux systèmes montrent qu’ils ne sont pas homologues et que les systèmes Xer à seule recombinase existent sous plusieurs versions. Ces résultats représentent la première découverte d’un espaceur de 11 paires de bases chez les tyrosine recombinases ainsi que la première étude in vitro sur XerH. / The chromosome dimers produced during the repair of circular chromosomes can be harmful to bacteria by blocking the segregation of the chromosome and cell division. To overcome this problem, bacteria use the Xer system for the monomerisation of chromosome dimers. It has two components, XerC and XerD, which act on the dif site and complete a recombination that will lead to the separation of the two copies of the DNA. The dif site is a DNA sequence where two imperfect inverted repeats separated by six base pairs allow the binding of each recombinase. This recombination is regulated by the protein FtsK, an essential member of the cell division machinery. The Xer system has been well studied in Escherichia coli and has also been characterized in a variety of species, for example Bacillus subtilis. Furthermore, in certain species of Streptococcus, studies have identified only a single recombinase, XerS, which acts on an atypical site named difSL in order to monomerize dimeric chromosomes. Not long after, a second system using a single recombinase was identified in a group of epsilon-proteobacteria. This recombinase was named XerH and the recombination site, difH, was found to more similar to difSL than to the classical dif sites. In this thesis, results from in vitro experiments on both systems are presented, as well as some results from in vivo experiments. We show that XerS is capable of binding cooperatively to difSL and that this binding is asymmetrical. This is because XerS is able to bind to the left half of the site but not to the right half when they are separated. The cleavage by XerS is also asymmetrical, as it is more efficient on the bottom strand. As for XerH, its binding to difH is much less cooperative and doesn’t have the same asymmetry. But the cleavage is also asymmetrical like the one seen in XerS. Comparing the two systems show that they are not homologuous and that more than one version of Xer systems using a single recombinase exists. These results represent the first discovery of an 11 bases pairs spacer for tyrosine recombinase. It is also the first in vitro studies of XerH.

Pas de résumé français / Pas de résumé anglais

Dans cette thèse, des simulations numériques ont d'abord été effectuées avec le logiciel FLAC (Itasca) sur un modèle de pente élastique linéaire homogène pour caractériser l'amplification de l'accélération le long de la surface située le long et à l’arrière de la crête d'une pente, et évaluer ainsi l'effet de la topographie sur l'amplification de l'accélération. L'interaction entre la fréquence du signal sismique appliqué à la base du modèle et l'angle et la hauteur de la pente a été particulièrement étudiée. Il a été constaté que le facteur d’amplification de l’accélération varie de manière significative avec l’angle de et la hauteur de la pente, la fréquence et la durée (nombre de cycle) du signal. De plus, l'amplification du mouvement du sol due à la topographie de la pente est influencée de manière significative par l'effet de couplage complexe entre les ondes incidentes et les ondes réfléchies sur la topographie, et qu’elle est fortement contrôlée par le rapport entre la longueur d'onde du signal incident et la hauteur de la pente.Les simulations numériques sont basées sur une étude géotechnique et une modélisation géomécanique nécessitant de valider les résultats par des comparaisons entre les résultats de modélisations et les données provenant des observations sur le terrain. L’analyse des domaines de fréquence, telle que la densité spectrale et la réponse en fréquence, est un moyen performant pour comprendre les caractéristiques des processus et les divers phénomènes qui ne peuvent pas être expliqués dans le domaine temporel. À cette fin, une étude de la crête du parc Xishan à Zigong au Sichuan en Chine a été réalisée. Les amplifications du site associées au mouvement du sol produit par le séisme de Wenchuan en 2008 ont été évaluées à l'aide de la technique du rapport spectral standard (SSR) et de la méthode d'accélération quadratique moyenne (arms) dans le domaine temporel. Une analyse numérique à 2D utilisant la méthode des différences finies au moyen du logiciel FLAC (Itasca) a été ensuite mise en œuvre et les résultats ont été comparés aux mesures de terrain. Les pics “simulés” des amplifications spectrales sont toujours inférieurs à ceux dérivés des enregistrements de terrain. L'effet d'atténuation important sur le mouvement d'entrée pour les hautes fréquences met en évidence le fait qu'un rapport d'amortissement du signal ne représente pas correctement la dissipation d'énergie dans les simulations numériques. Des amplifications significatives se sont produites à des fréquences élevées (> 10 Hz) et sont considérées comme résultant de conditions locales spécifiques telles que la fracturation des roches et les marches de faîtage; ils ne se produisent donc pas nécessairement au sommet de la colline.Enfin, des études paramétriques ont été réalisées avec des modèles élastiques en termes de diverses géométries de pente 2D et de couches géologiques de subsurface pour caractériser les amplifications du mouvement du sol. L’analyse paramétrique a pour but de comprendre le rôle joué par ces couches de surface, l’angle de la pente et la hauteur de la pente sur l’amplification du mouvement du sol,et donc d’évaluer si l’amplification du site peut être responsable du déclenchement du glissement de terrain. Ensuite, l'analyse dynamique sur des modèles de pente pour différentes magnitudes a été effectuée et une rupture de pente basée sur le déplacement a été créée pour évaluer la stabilité de la pente du site de Las Colinas au Salvador. Les résultats numériques ont clairement montré que les effets de site peuvent avoir induit d'importantes amplifications du mouvement du sol qui ont contribué à déclencher des glissements de terrain. / In this research work, numerical simulations using the finite difference FLAC software (Itasca) were first conducted with a homogeneous linear elastic slope model in order to characterize the acceleration amplification along the slope surface and behind the slope crest, and then to evaluate the topographic effect on the acceleration amplification. The interaction between the frequency of the seismic input motion applied at the base of the model with the slope angle and height has been deeply investigated. It was found that significant changes in the acceleration amplification factor result from variations in the slope angle and height as well as the signal frequency and duration. In addition, it has been shown that the ground motion amplification due to slope topography result from complex coupling effects between the input waves and the reflected waves on the topographic features and is highly controlled by the ratio between the wavelength of the input signal and the slope height.Numerical simulations are based on geotechnical investigations and geotechnical modeling, and it is necessary to validate the results through comparisons between modeling results and field observations. Frequency domain analysis such as spectral density and frequency response are an effective way to understand process characteristics and the various phenomena that cannot be explained in the time domain. For this purpose, a case study at Xishan Park ridge in Zigong in China has been studied. Site amplifications associated with the ground motion produced by the 2008 Wenchuan earthquake have been evaluated using the Standard Spectral Ratio (SSR) technique and root-mean-square acceleration (arms) method in time domain. 2D numerical analysis using finite difference method using the FLAC software (Itasca) has been then performed and results have been compared with monitoring data. The “simulated” peaks of the spectral amplifications are always lower than those derived from the field records. The strong attenuation of input motion at high frequencies highlights the shortcoming that a signal damping ratio does not adequately represent the energy dissipation in numerical simulations. Significant amplifications occurred at high frequencies (>10 Hz) and are considered to result from local specific conditions such as rock fracturing and ridge steps; thus they do not necessarily occur at the top of the hill. Finally, parametric studies were performed with elastic models in terms of various 2D slope geometries and geological layers to characterize the ground motion amplifications. The purpose of the parametric analysis is to understand the role of the geological layer, slope angle and slope height on the ground motion amplification, and thus to estimate if site amplifications could be responsible for the triggering of landslide. Then, the dynamic analysis on the slope model for different seismic magnitudes was performed and a slope failure based on displacement was created to evaluate the Las Colinas slope stability in Salvador. The numerical results clearly showed that site effects can have induced significant ground motion amplifications that contributed to trigger landslides.

La crise énergétique marquée par une flambée des prix du pétrole et les impératifs d’un développement durable font des énergies renouvelables une alternative qui suscitent aujourd'hui l’intérêt de plusieurs équipes de recherches. Le Sénégal, pays subsaharien, non producteur de pétrole n’est pas épargné par cette crise. Celle-ci se traduit par, une faible couverture du pays (en particulier les zones rurales) par le réseau électrique national. Pour faire face à cela, la nouvelle orientation en matière de politique énergétique met l’accent sur l’utilisation des énergies renouvelables notamment, le solaire et l’éolienne. L'objectif principal de cette thèse est de dégager une méthodologie de conception d’un site isolé de production d’énergie électrique à partir des énergies alternatives. Il s'agit à partir des caractéristiques d’un site (ressources d’énergie disponibles, besoins énergétiques) de :- mettre en place une démarche qui permette le choix d’une architecture du réseau et de dimensionner de façon optimale l’ensemble des constituants du réseau (machines, sources et dispositifs de stockage) en tenant compte de toutes les contraintes- concevoir un dispositif de commande des composantes et de gestion des flux d’énergie Cette thèse comprend trois chapitres :- Chapitre 1 : pose la problématique de l’énergie au Sénégal. L’organisation institutionnelle du sous-secteur de l’électricité, les réalisations et les projets en cours sont présentés. Aussi, une étude sur les architectures de micro-réseaux est faite. - Chapitre 2 : traite des outils et logiciels. Une étude comparative des principaux logiciels d’analyse, de conception et simulation des micro-réseaux est réalisée. L’ensemble des composants de notre système ont été modélisées. Les méthodes d’optimisation et des outils de représentation graphique (Bond Graph, GIC et REM) des systèmes ont été présentés. Une enquête menée et une recherche bibliographique nous ont permis d’évaluer le potentiel énergétique du site et les besoins des populations.- Chapitre 3 : il s’agit de l’application de notre outil sur un site isolé identifié au Sénégal (MBoro/Mer). L’optimisation à travers la fonction objectif coût annualisée du système (ACS) nous a permis de dimensionner de façon optimale notre système. Aussi la commande du système avec la Représentation Energétique Macroscopique (REM) a été conçue.Pour la suite du travail, il faudrait envisager une prise en charge des problèmes de disponibilité du système à travers une surveillance et une supervision du dispositif. Le volet socio-économique aussi est à intégrer dans le futur afin de satisfaire l’évolution des besoins et des habitudes des populations. / The energy crisis characterized by the oil products price rising and the imperatives of sustainable development do that renewable energies are an alternative today witch attract the interest of several research teams. Senegal, sub-Saharan country, not oil producer is not spared by this crisis. The consequence of this is a low coverage of the country (especially rural areas) by the national grid. For solving this, the new orientation of the energy policy focuses on the use of renewable energy particularly solar and wind.The main objective of this thesis is to identify a methodology of design of an isolated site of electrical energy production from alternative energies It is consists on, from site characteristics (energy resources, energy requirements):- to develop an approach that allows the choice of network architecture and sizing optimally all components of the network (machines, sources and storage devices) taking into account all the constraints- to design a device for controlling components and managing the energy flowsThis thesis contains three chapters:- Chapter 1 - poses the problem of energy in Senegal. The institutional organization of the electricity sub-sector and the ongoing projects are presented. Also, a study of micro- architectures networks is made.- Chapter 2 deals with tools and software. A comparative study of the main software of analysis, design and simulation of micro- network is realized. The components of our system have been modeled. Optimization methods and tools for graphical representation (Bond Graph, GIC and EMR) systems were presented. A survey and a literature review allowed us to evaluate the energy potential of the site and the needs of populations.- Chapter 3: This is the application of our tool on an isolated site identified in Senegal (MBoro / Mer). Optimization through the Annualized Cost of the System (ACS) objective function has allowed us to scale our system optimally. As the control system with Energetic Macroscopic Representation (EMR) has been designed.For further work should be considered a treatment of problems of availability of the system through monitoring and supervision of the system. The socio- economic component is also integrated in the future to meet the changing needs and habits of the population.

O estudo a seguir desdobra as questões de site specificity na arte contemporânea e suas modificações nas três últimas décadas. A compreensão do espaço em arte tomou novas formas não só em função dos espaços e dos discursos artísticos, mas também em função dos novos meios e linguagens. Essas mudanças demandaram alguns acompanhamentos por parte dos espaços expositivos, bem como um novo olhar sobre o que se entende por site specific art. Com base, principalmente nas propostas de Miwon Kwon, o presente material compara as obras de arte contemporânea, tecendo diálogos com as mudanças vistas. Espaços institucionalizados, como Inhotim, dialogam com a noção de site specificic arts, demonstrando as observações sobre site specificity. A pesquisa apresenta esta jornada e fornece subsídios para vislumbrar o espaço da arte contemporânea na segunda década do século XXI. / The following research unfolds site specificity matters on contemporary art and its changes for the last three decades. The comprehension of the space in art had reached new standards, not only due to artistic spaces and discourses, but also for new media and languages. Theses changes demanded some accomplishments at the exhibition spaces as well as new looks over what one understands as site specific art. Upon Miwon Kown premisses this study compares contemporary art works creating dialogs with the modifications already achieved. Institutionalized spaces, such as Inhotim, converse with site specific arts, what reinforces the need for a site specificity stare. The probe validates the jouney and endorses a fresh look over contemporary art on the second decade of the 21st century

Em meio às crises, surgem as ameaças e as oportunidades na Rede Mundial de Computadores. A Internet, âncora do Comércio Eletrônico, apresenta estas duas situações implícitas. Um grande acumulo de situações que se tornam ameaçadoras, as quais quando tratadas utilizando um embasamento científico, aprovado experimentalmente; são consideradas favoráveis, transformando-as em uma grande oportunidade de sucesso em uma próspera empresa, participante desse mundo virtual do comércio eletrônico na Internet. Com o intuito de colaborar com esta situação que envolve decisões importantes e estratégicas, grande volume de recursos, cujas soluções têm influência no futuro das organizações, esta dissertação propõe um modelo de avaliação para empresas de comércio eletrônico, visando sua melhoria contínua, através da aplicação recursiva desta avaliação. Tal modelo informado pelos juízos de valores daqueles responsáveis pelo site, objetiva identificar as limitações e potencialidades da empresa, diante dos cenários ameaçadores e oportunistas que se apresentam no momento de sua aplicação. Para a construção do modelo, foi eleita a metodologia Multicritério de Apoio à Decisão - MCDA, fundamentada cientificamente e com comprovada eficiência em aplicações práticas, considerada a mais adequada, por sua capacidade de gerar conhecimento aos participantes, através de um processo construtivista, e por sua capacidade de integrar tanto elementos objetivos quanto subjetivos. A partir da aplicação do modelo, será observado o perfil de desempenho de um site de comércio eletrônico mediante as ameaças e oportunidades existentes, sendo possível elaborar as recomendações e análises das ações, objetivando a melhoria da empresa de forma progressiva e contínua, servindo de referencial para aplicações futuras. / During times of crises, threats and opportunities will certainly arise in the computer World Wide Web. The Internet, an e-commerce anchor, presents both aforementioned situations. Many of these situations may become threatening, however, when treated by means of an experimentally proven scientific process, they can be changed into great opportunities for a company which participates in the Internet e-commerce virtual world. This situation involves important and strategic decisions, and a great amount of resources, which can lead to solutions that will have a great influence in the future of the organizations. In this way, this thesis proposes an evaluation model for e-commerce companies seeking continuous improvement by the recursive application of it. This evaluation model, that requires information provided by the site management, has as a goal to identify the company limitations and potentialities, in the presence of the threatening and opportunistic scenario existing at the moment of its application. For the development of the evaluation model, the MCDA - Multicriteria Decision Aid has been selected, as it is regarded as a scientifically well-founded methodology. Having its efficiency proven by practical applications, this methodology has been considered the most appropriate, because it generates knowledge to the participants, through a constructive process and for its capability of integrating both objective and subjective elements. Through the application of this model, the performance profile of the e-commerce sites will be observed, in face of the existing threats and opportunities. Thus, it becomes possible to elaborate the recommendations and analyses of actions to be taken, in order to improve the enterprise in a progressive and continuous way. Furthermore, this research can be used as a reference for future applications.

Submitted by William Justo Figueiro (williamjf) on 2015-07-06T23:18:29Z No. of bitstreams: 1 08a.pdf: 1546104 bytes, checksum: 91947cb60bc59adc136fd46a64431582 (MD5) / Made available in DSpace on 2015-07-06T23:18:29Z (GMT). No. of bitstreams: 1 08a.pdf: 1546104 bytes, checksum: 91947cb60bc59adc136fd46a64431582 (MD5) Previous issue date: 2013-07-26 / Nenhuma / O presente trabalho teve por objetivo a proposição e teste de um modelo teórico, a fim de verificar as dimensões da confiança e seus antecedentes qualidade do site e satisfação, que afetam a lealdade e o boca a boca do consumidor online, mais especificamente a confiança na internet, confiança em terceiras partes e a confiança no site fornecedor. Para atingir os objetivos deste estudo, buscou-se identificar na literatura as relações existentes entre os construtos pesquisados. Com base nos estudos revisados foi desenvolvido um instrumento com escalas já validadas em marketing em contexto de compras online, sendo avaliado e revisado por meio de pré-teste. A técnica de coleta de dados foi realizada através de uma survey, com 270 respondentes que compraram produtos eletroeletrônicos pela internet. A técnica estatística utilizada foi Modelagem de Equações Estruturais (MEE) por meio da qual foi testado o modelo e as respectivas hipóteses. Foi verificada também a mediação dos tipos de confianças: confiança na internet, confiança no site fornecedor e confiança em terceiras partes, entre os antecedentes qualidade do site e satisfação, influenciando na lealdade e no boca a boca do consumidor online. Os resultados indicaram um bom ajustamento do modelo de acordo com o que é proposto na literatura, indicando que a qualidade do site influencia as diferentes dimensões de confiança e a satisfação, a satisfação influência mais a confiança no fornecedor e esta é a que mais influencia a lealdade. Quanto ao teste de mediação, neste foi possível constar que existe a mediação total da confiança no site fornecedor entre qualidade do site e a lealdade. Além disso, verificou-se que a confiança na internet e em terceiras partes exercem influência no comportamento de lealdade e boca a boca, mas não afetam, a confiança no site do fornecedor. / Researchers in the area of management and marketing have studied the understanding of factors such as online consumer confidence, loyalty, site quality, satisfaction and word of mouth. The present work had as objective the proposition and testing a theoretical model to verify the dimensions of trust and their antecedents which affect the loyalty and word of mouth of online consumer, more specifically the internet trust, trust in third parties and confidence in the supplier site. To achieve the objectives of this study, it sought to identify in the literature the relationship among constructs searched. On the basis of the reviewed studies, it was developed an instrument with scales already validated in the context of online shopping marketing, being evaluated and reviewed through pre-test. The data was collected through a survey with 270 respondents who bought consumer electronics products over the Internet. The statistical technique used was Structural Equation Modeling (SEM) whereby model was tested and their hypotheses. It was tested even the mediation of the types of trusts: trust on the internet, trust and confidence in third party supplier, between the background of quality of the site and satisfaction, influencing on loyalty and word of mouth of the consumer. The results indicated a good model adjustment in accordance with what is proposed in the literature, indicating that the quality of the site influences the different dimensions of trust and satisfaction, the Sat more influence trust in supplier and this is the one that influences the loyalty. As for mediation, in this test it was possible to show that there is a total of mediation confidence in supplier site between the quality of the site and loyalty. In addition, it was found that confidence in the internet and in third parties exert a certain influence on the behavior of loyalty and word of mouth, but do not affect the tust in the supplier site. The implications of these analyses, both managerial and academic are presented in this study in order to contribute to the advancement of studies in the area.