Two main Arabidopsis thimet oligopeptidases (AtTOP) involved in stress responses are: (1) thimet metalloendopeptidase 1 (TOP1), found in the mitochondria and chloroplasts, annotated as At5g65620, and (2) thimet metalloendopeptidase 2 (TOP2), found in the cytosol annotated as At5g10540. Both AtTOP1 and AtTOP2 are located on chromosome 5 and share high homology. AtTOP1 and AtTOP2 are zincin-like metalloendopeptidases with the characteristic HEXXH active motif of the M3 clan. Their peptidase activity is related to the oxidative stress triggered by plant immune responses. AtTOPs are involved in plant immune responses through a mechanism regulated by Salicylic Acid (SA); both AtTOP1 and AtTOP2 bind plant SA, which inhibits their peptidase activities. However, we engineered a series of mutations to identify which cysteines are responsible for TOPs dimerization and other oxidative, structureunction related events. Each of the cysteine in TOPs (i.e., six cysteines in TOP1, and four cysteines in TOP2) were independently mutated to alanine, as a single mutant. The dynamics of the oxidative dimerization processes were measured using gel filtration and native gel methods to quantify the dimerization process of both native and mutant TOPs under variable redox potentials ex vivo and in vitro at various GSH/GSSG and DTTox/DTTred ratios, with the underlying hypothesis that the TOP dimerization and enzymatic activities are regulated by changes in the disulfide bond formation that is linked to cellular redox environments. Overall our results indicate that TOP1 is sensitive to changes in the redox environment, while TOP2 is not. The monomer/dimer ratio of TOP1 in solution is higher under highly reducing conditions compared to mildly and highly oxidative environments. Two TOP1 cysteines control the formation of dimers, one located in its N-terminal signal peptide (C52) and the other located in the peptidase domain (C611). These findings bring a mechanistic understanding of TOP1 and TOP2 functions in the plant immune response.

Due to increasing capacity of storage devices and speed of computer networks during last years, it is still more required to sort and search data effectively. Query result containing thousands of rows is usually useless and unreadable. In that situation, users may prefer to define constraints and sorting priorities in the query, and see only several top rows from the result. This thesis deals with top-k queries problems, extension of relational algebra by new operators and their implementation in database system. It focuses on optimization of operations join and sort. The thesis includes implementation and comparison of some algorithms in standalone .NET library NRank.

Doctor of Philosophy / Department of Physics / Andrew G. Ivanov / A search is performed for heavy vector-like top quark partner (T) with electric charge +2/3 by using proton-proton collision events from Large Hadron Collider (LHC) at a centre- of-mass energy of 13 TeV. The data corresponds to an integrated luminosity of 35.9fb−1 collected by the Compact Muon Solenoid (CMS) experiment during 2016. The production of this new hypothetical particle is assumed to be in pairs and strong interaction is responsible for such production mechanism. T quarks can decay to various combinations of third generation quarks and standard model bosons: T → bW, tZ, or tH, and hence the final states consist of pair of opposite-sign leptons consistent with coming from a Z boson and jets. No significant excess has been observed and hence 95% CL upper limits are obtained on TT production cross section by assuming different branching ratios. T quark mass values below 1280 GeV are excluded in case of 100% branching fraction for T → tZ.

Protein synthesis is frequently dysregulated in cancer cells; such conditions are known to favor aberrant cell growth and proliferation which lead to cancer. LARP1 is a novel target of the mammalian target of rapamycin complex 1 (mTORC1) signaling pathway, a circuitry often hyperactivated in cancer which regulates cell growth and proliferation primarily through the regulation of protein synthesis. I aimed to determine if LARP1 plays a role in cancer progression by comparing its expression in normal versus cancer tissues. My results demonstrate that LARP1 expression is altered (lost or overexpressed) in various cancers and correlates with cancer patients survival. My systematic bioinformatics assessment, the results of my functional assays assessing the effect of LARP1 knockdown on cancer cells, together with my antibody validation do not only provide new insights for its role in cancer progression and mRNA translation, but also emphasizes the potential of LARP1 as a cancer therapeutic target.

Cette thèse présente une étude de la production associée du boson de Higgs en association avec des quarks tops, suivie d’une désintégration du boson de Higgs en leptons tau, dans des collisions proton-proton (pp) à une énergie dans le centre de masse de sqrt(s) = 13 TeV enregistrées avec le détecteur CMS au Grand collisionneur de hadrons (LHC) du CERN.Ce travail s’inscrit dans le contexte du Run 2 du LHC, marqué par une augmentation de l’énergie dans le centre de masse de 8 à 13 TeV accompagnée d’une augmentation de la luminosité instantanée des collisions par rapport au Run 1. Pour faire face à ces nouvelles conditions de prise de données, CMS a entrepris une amélioration complète du système de déclenchement de niveau 1 accomplie avant 2016. Ce nouveau système et en particulier le nouvel algorithme électron et photon de niveau 1 ont contribué avec succès à un grand nombre de résultats CMS basés sur les données du Run 2. La mise en service de ce nouveau système ainsi que ces performances mesurées dans les premières données collectées par ce nouveau système de déclenchement sont présentées en détails.Une technique d’analyse novatrice basée sur la Méthode des Éléments de Matrice optimisée pour la recherche du processus ttH, H->tautau est également présentée, ainsi que plusieurs outils génériques pouvant âtre utilisés dans une large variété d’analyses H->tautau. Les résultats de l’analyse CMS utilisant cette méthode basés sur 35.9 fb-1 collectés en 2016 sont présentés. L’hypothèse "bruit de fond seul" est défavorisée mais n’est pas encore exclue par cette analyse à elle seule. / This thesis reports a study of the Higgs boson production in association with top quarks and decaying into τ leptons in proton-proton (pp) collisions at a center-of-mass energy of sqrt(s) = 13 TeV recorded with the CMS detector at the CERN Large Hadron Collider (LHC).This work has been carried out in the context of the Run 2 of the LHC, marked by an increase in the center-of-mass energy from 8 to 13 TeV together with an increase in the instantaneous luminosity of the collisions with respect to Run 1. To cope with this new data-taking conditions, CMS had initiated a full upgrade of the Level-1 trigger system achieved by 2016. This new system and in particular the new Level-1 electron and photon algorithm have successfully contributed to a large number of CMS results using Run 2 data. The commissioning of this new system and its performance measured with the first data collected with this new trigger are presented in details.A novel analysis technique based on the Matrix Element Method optimized for the search of the ttH, H->tautau process is also presented, including several generic tools which can be used in a large variety of H->tautau analyses. Results of the CMS analysis using this method based on 35.9 fb-1 collected in 2016 are presented. The background-only hypothesis is disfavored but not yet excluded by this analysis alone.

<p>The top quark is the most massive known elementary particle, and plays a pivotal role in our understanding of particle physics. Its unique properties offer valuable insights into the Standard Model and potential hints for physics beyond the Standard Model. In this thesis we present a precision measurement of the polarization of top quarks and spin correlations between top-antitop (ttbar) pairs using Run-II datasets collected from the Compact </p> <p>Muon Solenoid detector at the Large Hadron Collider. In the first part of this thesis we introduce the theoretical framework of the Standard Model and its predictions regarding top quark spin polarization and ttbar spin correlations. Next, we describe the experimental setup, reconstruction techniques, and Monte Carlo simulations used in this research. Subsequently, details of the measurement, including event selection, top quark reconstruction, and unfolding are described. The analysis achieves exceptional signal purity and precision with respect to previous measurements. The measured values of coefficients are in agreement with Standard Model expected values as well as theoretical predictions at NLO in QCD. In a first, we provide provide double-differential cross sections of top quark spin polarizations and ttbar spin correlations, as a function of the invariant mass of the ttbar system. We expect the results from the final CMS publication to supersede any results presented in the measurement part of this thesis document. In the final section of this thesis, we present a projection study of top quark spin polarization and tt ̄ spin correlations at the upcoming High Luminosity LHC. We present projections of the fraction of SM-like events and show that the upcoming detector could reduce uncertainties by as much as a factor 2. An alternative to the SM scenario is also considered in the form of Super Symmetry, and it is shown that we can significantly increase the ultimate reach of the LHC to discover top squarks in the degenerate mass corridor in the top squark-neutralino plane, or in the absence of a discovery exclude top squarks up to 600 GeV. </p>

A measurement of the fraction, f⁺, of right-handed W bosons produced in top quark decays is presented. This analysis is based on a sample corresponding to an integrated luminosity of 370 pb⁻¹, collected by the D⊘ detector at the Fermilab Tevatron pp Collider at √s = 1.96 TeV. The helicity angle, θ*, is reconstructed for each lepton. f⁺ is determined by comparing the cos θ* distribution from the data with that for the expected background and signal for various values of f⁺. The fraction of longitudinal W bosons, f⁰, is assumed to be 0.7 as predicted by the standard model. This yields f⁺ = 0.109 ± 0.094 (stat) ± 0.063 (syst), consistent with the standard model prediction of f⁺ = 3.6× 10⁻⁴. The possibility that both f⁺ and f⁰ stray from standard model values is also investigated. In this case cos θ* distributions for each possible W helicity state, along with the backgrounds, are fit to the cos θ* distribution for the data. The best fit values are f⁺ = 0.82 ± 0.30(stat) and f⁰ = −0.58 ± 0.50(stat).

No description available.

The goal of top-k ranking is to rank individuals so that the best k of them can be determined. Depending on the application domain, an individual can be a person, a product, an event, or just a collection of data or information for which an ordering makes sense. In the context of databases, top-k ranking has been studied in two distinct directions, depending on whether the stored information is certain or uncertain. In the former, the past research has focused on efficient query processing. In the latter case, a number of semantics based on possible worlds have been proposed and computational mechanisms investigated for what are called uncertain databases or probabilistic databases, where a tuple is associated with a membership probability indicating the level of confidence on the stored information. In this thesis, we study top-k ranking with uncertain data in two general areas. The first is on pruning for the computation of top-k tuples in a probabilistic database. We investigate the theoretical basis and practical means of pruning for the recently proposed, unifying framework based on parameterized ranking functions. As such, our results are applicable to a wide range of ranking functions. We show experimentally that pruning can generate orders of magnitude performance gains. In the second area of our investigation, we study the problem of top-k ranking for objects with multiple attributes whose values are modeled by probability distributions and constraints. We formulate a theory of top-k ranking for objects by a characterization of what constitutes the strength of an object, and show that a number of previous proposals for top-k ranking are special cases of our theory. We carry out a limited study on computation of top-k objects under our theory. We reveal the close connection between top-k ranking in this context and high-dimensional space studied in mathematics, in particular, the problem of computing the volumes of high-dimensional polyhedra expressed by linear inequations is a special case of top-k ranking of objects, and as such, the algorithms formulated for the former can be employed for the latter under the same conditions.

No description available.