Ce travail de thèse porte sur l’étude des ARN polymérases ARN dépendant impliquées dans le RNA silencing chez Arabidopsis thaliana. Durant ma thèse, la recherche d'interacteurs des RDR, parmi des protéines impliquées dans le RNA silencing, a permis la détection d'interaction entre RDR6 et SDE3, RDR6 et SGS3, mais aussi entre SDE3 et SGS3 en Co-IP et BiFC. Une co-localisation de ces protéines a été observée lorsqu'elles sont produites transitoirement dans des cellules épidermales de N. benthamiana.Un crible d’une banque d’ADNc d’A. thaliana par double hybride de levure, a permis d’isoler des interacteurs potentiels de RDR6. Deux interacteurs potentiels, AtUAP56-1 et U2B’’, sont impliqués dans l’épissage des précurseurs des ARNm. Un effet sur le RNA silencing dans des mutants de l’épissage en 3’ des ARNm était connu et nous avons confirmé l’interaction entre RDR6 et AtUAP56-1 par BiFC. L’étude de lignées mutantes pour AtUAP56-1 a donc été initiée.Une étude biochimique de RDR6 et de RDR2 a été réalisée. Des formes recombinantes de RDR2 et RDR6 ont été produites de façon transitoire dans des feuilles de N. benthamiana, et une étude comparative de RDR2 et RDR6 a été réalisée. Les deux RDR sont actives sur des matrices ARN et ADN, et montrent in vitro une activité amorce-indépendante. De plus, nous avons détecté pour la première fois une activité amorce-dépendante de RDR6 et RDR2. Ces résultats apportent de nouvelles données biochimiques qui sont en accord avec les études menées in vivo et enrichissent les modèles actuels du RNA silencing. / The aim of this work was to study RNA-dependent RNA polymerases involved in RNA silencing in Arabidopsis thaliana. During my thesis, the search for RDR interactors among proteins involved in RNA silencing allowed the detection of interactions between RDR6 and SDE3, RDR6 and SGS3, and also between SDE3 and SGS3 using Co-IP and BiFC. In addition, the co-localisation of these proteins was observed when produced transiently in epidermal cells of N. Benthamiana.A screen of an A. thaliana cDNA library by yeast two hybrid allowed us to identify some putative new RDR6 interactors. Two putative RDR6 interactors, AtUAP56 and U2B’’, are known to be involved in pre-miRNA splicing. Furthermore, a link between pre-mRNA 3’ splicing and RNA silencing was previously reported. We also confirmed the interaction between AtUAP56-1 and RDR6 by BiFC. An investigation of A. thaliana of AtUAP56-1 mutants has been initiated.Recombinant RDRs were produced transiently in N. Benthamiana, and a biochemical comparative study of RDR2 and RDR6 performed. We found that RDR2, like RDR6, has a de novo polymerase activity on DNA and RNA templates, and for both RDRs we also showed, for the first time, a primer-dependant synthesis of dsRNA from RNA template. These findings provide important new insights into our understanding of the molecular mechanisms of RNA silencing amplification in Arabidopsis.

Despite the high profile nature of the interventions made by regulators after the global financial crisis, there have been few objective assessments of their success and of the orthodoxy of market failure analysis that underpins the rationale for taking action. This study addresses both literature gaps by developing a distribution landscape segment model to measure the success of an exemplar; the Retail Distribution Review (RDR). It also undertakes exploratory research to establish a basis for a diagnostic paradigm based on customer value rather than well established, but criticised, classical economic indicators. A “stock flow” based model was constructed to assess post-RDR levels of asymmetry, agency and trust. The absence of source data prompted a second exploratory phase of research into Trust as a welfare benefit, using customer focus groups and telephone surveys. An evidential basis for an alternative framework based on what consumers value, rather than how economists think is rational for them to act, was established. The model results indicated a landscape which is more complex than 2013, with competing interests transmuted rather than eradicated and information asymmetry growing rather than shrinking. The results support a view that interventions focussing on narrow “market” definitions do not reflect the complexity of human behaviour and are simply “squeezing the balloon”. The customer value research found that trust is complicated and related to several key “motivators”. These have underlying attributes which differ between socio economic groups, the financial objectives and whether customers have advisers. The conclusion reached is that an evidence based customer perspective should be at the heart of regulatory analysis, if public welfare is to be maximised. The study provides evidence of complexities and connectedness between actors and economic forces in the retail financial services landscape, cautiously supporting the literature on regulatory interventions as socio-technical assemblages. It argues that the customer value framework enriches the regulatory toolkit by forming a guard against intellectual capture and unintended consequences of shaping reality to fit a so-called perfect market model.

Approved for public release; distribution in unlimited. / This research develops a detection rate model to analyze the effectiveness of the RDR 1500B search radar installed in the CASA 212 S43 aircraft belonging to Venezuelan Naval Aviation. The model is based on a search and detection mission to find a diesel submarine executing an incursion inside the Venezuelan Caribbean Sea area, assumed to be intermittently operating with periscopes or masts exposed above the sea surface. The analysis obtains cumulative probability of detection vs. time based on the radar manufacturer's performance data, user inputs for aircraft search area size, search speed, and search altitude, and submarine periscope or mast exposure profile. The model can use given periscope radar cross section data, or roughly calculate radar cross section given assumptions about exposed periscope height above the sea-surface and sea-state conditions. Submarine evasion due to radar counterdetection is also modeled. / Lieutenant Commander, Venezuelan Navy

BCC metals are commonly used throughout the world and understanding their deformation behavior, especially at the sub-grain level, is essential for their continued use in technological advancements. Correctly and confidently characterizing the active slip systems in BCC materials has been a difficult task throughout past research. The research described in this thesis utilizes high resolution digital image correlation (HRDIC) and relative displacement ratio (RDR) analysis to accurately characterize active slip systems in large grained BCC tantalum and provides new insights into dislocation nucleation sites, relative CRSS values for {110} and {112} slip systems, the correlation between GB transmission factors and strain gradients, the relative length of NBGZs, and slip transmission. A 99.99% pure tantalum oligo sample was sputtered with gold and remodeled to provide high resolution data points to be used in HRDIC. The high resolution of the gold remodeled samples combined with a RDR analysis made it possible to confidently identify active slip systems during tensile deformation at room temperature. One of the observations from this analysis was the discrepancy between the observed active slip systems and those predicted from a simple single-CRSS Schmid's Law. By considering the active systems observed in grains with a range of orientation, it was concluded that the {112} slip systems have a higher CRSS than the {110} by 6.7%. Independent CPFE simulations and experiments on single crystal samples of the same material, agreed with our findings establishing a range of increased CRSS for {112} of 3.9%-7.1%. These conclusions are compared with the small number of available estimates of the CRSS ratio, and lie in between the value of equal CRSS used by most modelers, and experimental estimates of 15-25% higher for {112}. The identified active slip systems were also used in the Luster and Morris equation to calculate each GBs transmissivity factor - an estimate of strain incompatibility between neighboring grains. Results indicate that there is an inverse correlation between GB transmissivity and strain gradient slope, as well as a positive correlation between GB transmissivity and slip trace reorientation for some GBs. Only one instance of slip transmission was observed from the 24 GBs analyzed, suggesting it is an uncommon occurrence in BCC tantalum. An analysis of the length of the NBGZ in relation to slip and strain gradients was compared to previous studies and suggests the relative and absolute length of the NBGZ changes with grain size, at least for large length scales. Strain gradients for each side of the GB were measured and results indicated steep negative strain gradient slopes that suggest dislocation nucleation in the GBs and propagation towards the interior of the grain. When compared against the transmissivity factor, an inverse relationship was found to exist between strain gradients and high transmissivity factors.

En 2010, les Ivoiriens organisaient une élection présidentielle au sortir d’une décennie de guerre civile. Depuis lors, ces élections défraient la chronique, en raison de leur issue critique : crise postélectorale meurtrière en 2011, réconciliation nationale poussive et, depuis 2016, mutineries dans les rangs d’une armée composite et de transition. La présente étude considère ces élections ivoiriennes de 2010 comme un objet d’étude scientifique et se consacre à la communication politique de campagne de trois « grands candidats » : Henri Konan Bédié du Parti Démocratique de Côte d’Ivoire (PDCI), Laurent Gbagbo de la Majorité Présidentielle (LMP) et Alassane Ouattara du Rassemblement Des Républicains (RDR). L’objectif scientifique est ici de déterminer les différents axes de communication partisane, qui éclairent le profil sociopolitique et le comportement de l’électeur ivoirien aux présidentielle de 2010. Plus spécifiquement, nos investigations sont consacrées, d’une part, à la détermination de l’électorat ivoirien dans sa composition sociale, politique et culturelle, mais aussi psychosociologique. Cet électorat est ici défini en termes d’intentions de vote, ou de motivation à voter pour tel ou tel candidat. D’autre part sont observés les moyens de communication utilisés par ces candidats majeurs qui deviennent des points structurants du champ politique ivoirien en s’endossant aux partis mandataires. Dans cette confrontation électorale pour capturer la majorité des voix interfèrent des représentations et des imaginaires politiques très marqués, qui consacrent ces candidats en challengers de la vie politique nationale et des sondages du moment. Ces enjeux affectent et différencient les stratégies de communication politique de campagne, que la thèse analyse en collectant les données et les ressources qui les influencent en sourdine et structurent autant les discours que les pratiques médiatiques des candidats étudiés. En clair, le contexte électoral de 2010 et ses déterminants sociohistoriques forgent les stratégies de communication et le comportement médiatique des candidats majeurs. / At the end of the year 2010, the Ivorians organized a presidential election after a decade of civil war. Since then, these elections are still in the news because of their critical outcome: murderous post-electoral crisis in 2011, complicated national reconciliation and, since the year 2016, mutinies in the ranks of a composite and transitional army. This study considers the Ivorian presidential elections of 2010 as a social sciences study subject and is devoted to the political campaign communication of three "great candidates" : Henri Konan Bédié of the Democratic Party of Côte d'Ivoire (PDCI), Laurent Gbagbo of the Presidential Majority (LMP) and Alassane Ouattara of the Rally of Republicans (RDR). The scientific purpose here is to determine the different axes of partisan communication, which illuminate the socio-political profile and behavior of the Ivorian voter in the 2010 presidential election. More specifically, our investigations are devoted, on the one hand, to the determination of the Ivorian electorate in its social, political and cultural composition, but also psycho-sociological dimension. This electorate is here defined in terms of voting intentions, or motivation to vote for a particular candidate. On the other hand are observed the means of communication used by these major candidates who become structuring points of the Ivorian political field by endorsing the mandatory parties. In this electoral confrontation to capture the majority of voices, the study shows how interfere a very strong political representations and imaginings, which consecrate these candidates into challengers of national political life and polls of the moment. These issues affect and differentiate campaign political communication strategies, which the thesis analyzes by collecting data and resources that influence them below and structure both the speeches and the media practices of the candidates studied. Clearly, the electoral context of 2010 and its sociohistorical determinants forge communication strategies and the media behavior of major candidates.

The RNA interference is a mechanism, which allows cells to regulate their genes functions, to establish and maintain heterochromatin and to defend them against invasive nucleic acids. In plants, RNA interference is initiated by double-stranded RNA, which is processed by Dicer into small RNAs, usually 20-24nt long. These small RNAs form a complex with Argonaut protein that participates in different processes based on sequence complementarity. This complex can guide mRNA cleavage, translation blocking and chromatin modifications, resulting either into posttranscriptional silencing (by preventing translation of already existing mRNA, PTGS) or transcriptional silencing (by preventing transcription of mRNA, TGS). The first step of this thesis was to establish different ways of triggering PTGS and to evaluate their functionality and efficiency. The next step was a preparation of a system which would allow to study the transition from posttrancriptional to transcriptional silencing. These so called "indicator lines" should allow to observe the timing and dynamics of this process by utilizing fluorescent proteins. This system is also going to enable to evaluate, how different factors are involved in this process - one of the factors is RNA-dependent RNA polymerase 6 (RDR6) which plays an essential role in...