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Trabelsi, Ahmed. "Modulation des niveaux de résistance dans une mémoire PCM pour des applications neuromorphiques". Electronic Thesis or Diss., Université Grenoble Alpes, 2024. http://www.theses.fr/2024GRALT027.
Pełny tekst źródłaThe exponential growth of data in recent years has led to a significant increase in energy consumption, creating a pressing need for innovative memory technologies to overcome the limitations of conventional solutions. This data deluge has resulted in a forecasted consumption surge in data centers, with an expected fourfold increase in data by 2025 compared to the present volume. To address this challenge, emerging memory technologies such as RRAM (Resistive RAM), PCM (Phase-Change Memory), and MRAM (Magnetoresistive RAM) are being developed to offer high density, fast access times, and non-volatility, thereby revolutionizing storage and memory solutions (Molas & Nowak, 2021).One promising technique to address the need for innovative memory technologies is the use of frequency modulation to modulate resistance in PCM which is a crucial aspect of its use in neuromorphic computing. PCM is a non-volatile memory technology based on the reversible phase transition between amorphous and crystalline phases of certain materials. The ability to alter conductance levels makes PCM well-suited for synaptic realizations in neuromorphic computing. The progressive crystallization of the phase-change material and the subsequent increase in device conductance enable PCM to be used in neuromorphic applications. Additionally, PCM-based memristor neural networks have been developed, and the resistance drift effect in PCM has been quantified, opening up new paths for the development of PCM-based memristor neuromorphic accelerators. Furthermore, frequency modulation has been identified as a promising technique to modulate resistance in PCM. This approach can be applied to PCM as well as RRAM, and it is expected to yield improved learning effects in more complex networks using multi-level cells (Wang et al., 2011). The primary aim of this thesis is to explore innovative methods for controlling resistance levels in PCM devices with a focus on their application in neuromorphic systems. The research involves a comprehensive understanding of the mechanisms underlying PCM devices and an identification of parameters that may influence the reliability of these devices. Additionally, the thesis aims to propose a novel approach to effectively modulate resistance levels in PCM devices, contributing to advancements in this field
Girisit, Hermine. "Gérer la résistance au changement : contribution de la mesure des niveaux de résistance des acteurs dans les projets de changement". Thesis, Lyon 3, 2013. http://www.theses.fr/2013LYO30010/document.
Pełny tekst źródłaEvery company, by choice or by necessity, must constantly adapt itself to various economic, technological and social environment changes. From this perspective, the internal and external changes are needed in order to optimize the existing of the company. To anticipate these changes and to be successful, organizations need to consider an appropriate strategy taking into account the human dimension, because any modification or termination of work practices can destabilize the habits of actors and in some cases can cause resistance mechanisms. In the academic literature and in the managerial discourse, the resistance to change is often presented as a negative led by a minority of individuals impacting significantly change projects. In this sense, the study of understanding and measuring resistances actors is essential for managing change in an organization. Our study demonstrates that, in order to not jeopardize the success of the change project, an analysis of resistance levels is necessary for the manager to minimize the effects of the actor’s resistance to change. This diachronical research has allowed us to monitor the behavior of actors, a proposed change in the medical industry, to bring out the main characteristics and resistance levels. The interest of this study is to determine the different levels of resistance, to identify the possible obstacles, that the manager will have to deal and then to propose appropriate solutions to achieve positively the change in the company
Turner, Marie. "Plusieurs niveaux de contrôle sont mis en jeu lors de flétrissement bactérien chez la légumineuse modèle Medicago truncatula". Thesis, Toulouse, INPT, 2009. http://www.theses.fr/2009INPT011A/document.
Pełny tekst źródłaManquant
Duval, Emmanuel. "Caractérisation de structures MIS par spectroscopie d'admittance : évaluation du comportement dynamique des défauts à l'interface isolant-semiconducteur". Rouen, 2001. http://www.theses.fr/2001ROUES041.
Pełny tekst źródłaDefects at insulator-semiconductor interface are studied on <100> oriented MIS structures with three complementary electrical characterisation techniques : the conductance spectroscopy G([omega]), the capacitance method C(V), and ultraviolet assisted capacitance analysis. The advantage of high temperatures sweeping has been demonstrated. The comparison between G([omega],T) and C(V,T) methods designates the first one as the most powerful. G([omega],T) spectroscopy enables the separation of slow and fast states contributions. Moreover, this techniques leads to donor and acceptor states detection associated to trivalent defects. This detection is confirmed by UV assisted capacitance measurements. Our results are in good agreement with those published about different characterisation methods. This work shows conductance spectroscopy as a very powerful tool to quantify slow and fast states contributions and to identify trivalent defects at insulator-semiconductor interface
Normand-Lauzière, François. "Anomalies postprandiales du métabolisme des acides gras libres dans l'évolution naturelle du diabète de type 2". Mémoire, Université de Sherbrooke, 2010. http://hdl.handle.net/11143/5545.
Pełny tekst źródłaFathi, Riyad Abdullah. "Étude et sélection de jeunes plants d'eucalyptus tolérants au sel, dans les populations de divers niveaux de variabilité". Nancy 1, 1987. http://www.theses.fr/1987NAN10292.
Pełny tekst źródłaDulaurent, Anne-Maïmiti. "Effet de la diversité des essences forestières sur les niveaux de population de la processionnaire du pin (Thaumetopoea pityocampa), à différentes échelles spatiales, dans la forêt des Landes de Gascogne". Thesis, Bordeaux 1, 2010. http://www.theses.fr/2010BOR14176/document.
Pełny tekst źródłaMixed forests are less prone to insect damage than pure forests because ofreduced host accessibility and/or improved control by natural enemies. To test thesehypotheses, we have studied the ecology of the pine processionary moth (PPM)(Thaumetopoea pityocampa) and its parasitoid, in a monoculture of maritime pine(Pinus pinaster) plantations, the Landes de Gascogne forest. There, open areas(firebreaks, clear cuts) and patches of broadleaved woodlands (hedgerows, riparianforest, natural forest remnants) still persist locally. In this study we have shown that:(1) Pine stand colonization by PPM was limited by the presence ofbroadleaved hedgerows at stand edge. Broadleaved trees formed physical barriersdisrupting the visual detection of pine trees by PPM females when searching for anoviposition site.(2) The longevity of the two main PPM egg parasitoids increased whenspecimen were fed with honeydew produced by oak aphids. The generalist species,which emerges two months before PPM, could benefit from this longer lifespan tooverlap its host emergence.(3) PPM pupae survived better in the soil of open areas than under forestcovers (pine or broadleaved trees), because of higher temperature and humidity. Theassociation between pine stands and open areas benefits PPM through habitatcomplementation, whereas the presence of broadleaved trees may act as anecological trap for PPM caterpillars.(4) Maritime pine stands within heterogeneous landscapes exhibited lowerPPM infestations than similar stands within pine monocultures. PPM infestation levelsdecreased with increasing percent broadleaved area in the surrounding landscape.These results are discussed according to the ecological mechanisms whichmay explain the relationship between insect herbivory and tree species diversity.Perspectives for improved PPM management in the Landes de Gascogne forest, andfor further scientific research are proposed
Schlegel, Laurent. ""Streptococcus pneumoniae" résistant à la pénicilline isolé du LCR et haut niveau de résistance aux aminosides : étude "in vitro" des cinétiques de bactéricidie des associations bêta-lactamines-aminosides". Paris 5, 1995. http://www.theses.fr/1995PA05P013.
Pełny tekst źródłaDupuis, Morgan. "Susceptibilté et résistance à l'hypertension : mécanismes moléculaires impliqués au niveau de la paroi artérielle". Paris 6, 2006. http://www.theses.fr/2006PA066358.
Pełny tekst źródłaBenomar, Yacir. "Intéractions entre les voies de signalisation de la leptine et de l'insuline au niveau neuronal : rôle dans l'établissement de la leptino-résistance et/ou l'insulino-résistance". Paris 11, 2006. http://www.theses.fr/2006PA11T031.
Pełny tekst źródłaAslangul, Élisabeth. "Résistance de niveau intermédiaire à la gentamicine chez Enterococcus faecalis : sélection, étude du mécanisme et impact thérapeutique". Paris 7, 2005. http://www.theses.fr/2005PA077194.
Pełny tekst źródłaThe association of a cell-wall active antibiotic (amoxicillin or glycopeptid) with gentamicin is required to treat severe enterococcal infections. Aquired antibiotic resistance in enterococci affects glycopeptides, especially vancomycin, and gentamicin. VanB enterococci are resistant to vancomycin, susceptible to teicoplanin. Both glycopeptides and gentamicin alone selected resistant mutants in E. Faecalis. The association of teicoplanin and gentamicin was efficient and prevented the emergence of resistance. High level gentamicin resistance (MIC ≥ 500 μg/ml) is confered by modifying enzymes in enterococci and prevents synegism. We described a new gentamicin mechanism of resistance in E. Faecalis, by uptake impairement wich prevent Amo synergism when the MIC is greater than 500 μg/ml. Time-kill curves are not predictive of the efficacy in vivo. We developped a new non isotopic method of intracellular gentamicin concentration determination
Barff, Teura. "Caractérisation des gènes candidats régulés au niveau traductionnel durant la réponse de défense NB-LRR des plantes". Mémoire, Université de Sherbrooke, 2018. http://hdl.handle.net/11143/11898.
Pełny tekst źródłaKrzyzaniak, Yuko. "Impact de biostimulants sur le niveau d'induction de résistance de la vigne contre le mildiou par des éliciteurs". Thesis, Bourgogne Franche-Comté, 2018. http://www.theses.fr/2018UBFCK008/document.
Pełny tekst źródłaThe protection of vineyards against cryptogamic diseases such as downy mildew is mainly ensured by synthetic fungicides, which cause serious environmental and health problems. The induction of resistance by elicitors could allow to reduce their use. However, even if their efficacy is demonstrated in greenhouse conditions, it remains quite variable in field conditions. Indeed, the efficacy of an elicitor depends on the plant’s ability to respond, or more generally, on the latter’s physiological status. In this context, part of the FUI project IRIS+, the aim of this present work is to evaluate whether biostimulants, through their effect on the plant’s physiology, would be able to increase their responsiveness to elicitors. The activation of defenses implies a metabolic and energetic cost that the plant must get in charge. First of all, we used a cell suspension model in order to compare two oligosaccharidic elicitors on the primary metabolism of grapevine. Enzymatic and metabolic analyses showed that the oligogalacturonide, which had a stronger impact on secondary metabolism related to defense, compared to laminarin, also showed a more notable impact on primary metabolism, particularly on some sugars and amino acids. The elicitation of grapevine defenses effectively turned out to require resources. Secondly, a screening was carried out to select the most effective elicitor among seven products that were provided by the company. Protection assays against Plasmopara viticola on herbaceous cuttings allowed us to identity SDN3 as the most interesting candidate. In vitro and in planta studies revealed that the mode of action of SDN3 relied on both the activation of defenses and a direct effect against the pathogen. Lastly, as no protocol, nor methodology were available in our laboratory to screen biostimulants, four systems were developed, in order to monitor phenotypic traits of aerial and/or root system: the “pot” model, the “rhizotron” model, the “tubes”, and another termed “X” (no description allowed because of an industrial protection). Only the “X” model showed potential interests, since it allowed to display biostimulating effects such as the acceleration of the bud opening, and the increase of the mean number of primary roots, in response to BS3, applied to the roots. The development of the protocol to apply the elicitor and to infect with P. viticola spores are currently in progress, in order to assess the initial hypothesis by using the combination of BS3 and SDN3
Sellier, Manuel. "Evaluation des futures technologies CMOS (<50nm) au niveau circuit". Phd thesis, Université de Provence - Aix-Marseille I, 2008. http://tel.archives-ouvertes.fr/tel-00631246.
Pełny tekst źródłaBourgeois, Sandrine. "Conception d'un médicament prototype visant à hydroliser le résidus d'antibiotiques au niveau du colon". Paris 11, 2004. http://www.theses.fr/2004PA114823.
Pełny tekst źródłaIt is now recognized that the increased resistance of bacterial pathogens is in most instances related to an increased resistance in commensal intestinal flora followed by horizontal transfer of resistance to pathogenic species. Particles for the colon delivery of b-lactamases (BL) have been designed for degradation of residual antibiotics and to minimise resistance to b-lactams. This was obtained with pectin beads cross-linked with polyethylenimine (PEI). Protein stability in beads was mainly influenced by the amount of residual water within the particles which increases with the increase of free calcium chloride in beads. Indeed, the elimination of free calcium chloride by washing the particles with distilled water led to a decrease of the moisture content in beads and reduced the exposure of encapsulated proteins to hydrolysis. Moreover, the presence of PEI in beads considerably improved their stability and the stability of encapsulated BL in simulated gastrointestinal media. In vitro studies in simulated digestive fluids showed that BL were specifically released from pectin beads in the colonic medium by the action of pectinolytic enzymes. Finally, high amounts of enzymes were found in the feces after oral administration of the beads to mice. Multiparticulate systems for site-specific colonic delivery of BL were designed in order to fight the spreading of resistant bacterial strains in the environment due to the intensive antibiotic use
Marthinet, Eric. "Modulation du phénotype typique de multichimiorésistance (MDR) des cellules cancéreuses humaines par des leurres transcriptionnels et étude de la régulation transcriptionnelle du gène MDR1 au niveau de la région MED-1". Lyon 1, 2001. http://www.theses.fr/2001LYO10021.
Pełny tekst źródłaPelletier, Cindy. "L'interprétation d'une nouvelle littéraire résistante par des adolescents québécois de 14 à 17 ans". Master's thesis, Université Laval, 2017. http://hdl.handle.net/20.500.11794/27990.
Pełny tekst źródłaPalich, Romain. "Impact de la résistance virale acquise dans le passé sur les stratégies antirétrovirales actuelles". Electronic Thesis or Diss., Sorbonne université, 2021. http://www.theses.fr/2021SORUS493.
Pełny tekst źródłaIn the field of HIV management, today in France, three situations continue to concern clinicians: 1) persistent low-level viremia, despite prolonged antiretroviral treatment and good self-reported compliance, 2) persistence or clearance in viral reservoir of resistance mutations selected in the past, and 3) optimal drug-reduced antiretroviral treatment in virally suppressed patients. In a first work, we showed that 72% of patients with persistent low-level viremia, with good self-reported compliance, had adequate plasma antiretroviral concentrations, and no past viral resistance explaining the persistent replication. Two years after inclusion, 72% of patients maintained low-level replication without virologic failure. In a second work, we showed the persistence of the M184V mutation, acquired in the past, in 67% of patients with suppressed viremia >5 years (detection threshold: 1%), as well as the progressive clearance of the mutation in the HIV-DNA reservoir. The two factors associated with the persistence of M184V were the duration and the level of replication under 3TC/FTC in the past. In a third work, we showed the virological efficacy of dual therapies given 5 or 4 days a week (virological success: 91% at W96), in a population highly exposed to antiretroviral treatment. Overall, these findings support the optimization of strategies, in order to reduce the exposure to antiretrovirals, including in patients with a long virological and therapeutic history
Savourey, Gustave. "Réactions thermorégulatrices et mécanismes adaptatifs au froid chez l'homme : relations avec le niveau d'aptitude physique aérobie mesuré par VO2 max". Lyon 1, 1992. http://www.theses.fr/1992LYO1T186.
Pełny tekst źródłaPeyrat, Marie-Bénédicte. "Etude de l'influence du nettoyage et de la désinfection et des procédés d'abattage en abattoir de volaille sur le niveau de résistance aux antibiotiques des campylobacters". Phd thesis, Université Rennes 1, 2008. http://tel.archives-ouvertes.fr/tel-00288961.
Pełny tekst źródłaBecker, Loïc. "Identification et suivi par spectrométrie de masse de composés impliqués dans la défense des feuilles de vigne caractérisées pour leur niveau de résistance au mildiou". Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0101/document.
Pełny tekst źródłaDowny mildew, caused by the Plasmopara viticola pathogen, is a fungal disease which can induce serious harvest damages. To avoid these losses, it is necessary to use phytosanitary treatments. In addition to their financial cost, winegrower’s health issues and the environment protection cannot be ignored. However, all grapevine varieties do not present the same sensitivity to the pathogen. Indeed, despite of poor organoleptic qualities, American varieties are resistant to this disease. Combining them with European species by varietal crossing may be a viable alternative to these treatments. However, to lead efficiently these cross breeding programs, it is necessary to know more about the relationship "host-pathogen". In this context, analysis by mass spectrometry has been used under different aspects
Peyrat, Marie-Bénédicte. "Étude de l’influence du nettoyage et de la désinfection et des procédés d’abattage en abattoir de volailles sur le niveau de résistance aux antibiotiques des campylobacters". Rennes 1, 2007. http://www.theses.fr/2007REN1S038.
Pełny tekst źródłaCampylobacter is a common cause of human bacterial enteritis and consumption of poultry products is a major source of human infection. It has been suggested that disinfectants and environmental stress can lead to changes in the nature and scale of antibiotic resistance expressed by bacteria. In order to investigate this hypothesis, sampling of poultry and environment in 4 unrelated slaughterhouses were conducted. Minimal inhibitory concentrations (MIC) against 6 antibiotics and 2 disinfectants were measured for all the isolates collected. Genotype profile of selected isolates collected after cleaning and disinfection and from poultry carcasses was done by PCR-restriction fragment length polymorphism of P/fla///gyr/A and /fla/A genes. Our results indicate that campylobacter is able to survive overnight on surfaces of poultry slaughterhouses and that these strains may contaminate carcasses during the slaughter process. Our results also suggest that cleaning and disinfection procedures and shlaughter procces don’t lead to increase antibiotic resistance in campylobacter
Bascou, Joseph. "Analyse biomécanique pour la compréhension et l’amélioration du fauteuil roulant dans son application au tennis de haut niveau". Thesis, Paris, ENSAM, 2012. http://www.theses.fr/2012ENAM0048/document.
Pełny tekst źródłaThe development of Paralympics has done a lot for a more positive image of handicap and has opened up new opportunities for the practice of disability sport, known to be highly beneficial for the physical and psychological health of disabled people. Conducted in close partnership with a high level tennis player, this study focuses on the influence of the wheelchair settings on its behavior in order to adapt this behavior to wheelchair tennis playing. The study first highlighted the forces of resistance to straight line or rotating wheelchair movements, thanks to mechanical models validated by experiments. Then, the inertial parameters of the seated player's body segments were assessed by adapting a volumic model to the sitting position, and his propulsion at maximal velocity was studied, in order to understand the effect of the seat fore-and-aft position on this movement. Then, an experimental study proved the major influence of the center of gravity position on free rotation, which was modelized too.In a nutshell, this research work has led to a better understanding of the effects of the wheelchair settings on its behavior, its results have allowed to modify various settings on our partner's wheelchair and can be used as a basis for future wheelchair conception/design. They have also proved useful for conventional wheelchairs and in the meantime, our tennis player partner has become wheelchair tennis world champion…
Bouvier-Slekovec, Céline. "Prévention et maîtrise des infections nosocomiales selon trois approches appliquées à différents niveaux d'action". Thesis, Besançon, 2013. http://www.theses.fr/2013BESA3008/document.
Pełny tekst źródłaBacterial resistance to antibiotics in health care facilities complicates the therapeutic burden and increased mortality of infected patients. The objective of this work was to evaluate different approaches which aim was to prevent and control hospital-acquired infections. This work focuses on three issues: (i) Is there a strategy already in place to promote the appropriate use of antibiotics? (ii) How can we evaluate performance in terms of hand hygiene? (iii) What measures can we implement to limit the spread of P. aeruginosa?We first showed that the distributions of regional guidelines or drug monitoring alerts were followed by a change in the uptake of antibiotic prescriptions in line with such recommandations.Then we evaluated the performance of health care facilities for hand hygiene, focusing especially on the index of consumption of alcohol-base hand-rub solution. We showed that the number of alcohol-based hand-rub is far higher than that defined by the French Ministry of Health. In another study, we were faced with limitations in its construction, the latter being partly responsible for the lack of a relationship between this indicator and the prevalence of invasive devices associated with infections.Finally, we have shown that the burden of care and the contamination of clean water networks of health facilities were contextual risk factors for acquisition of Pseudomonas aeruginosa. Another study showed that wastewater networks were involved in extra-hospital spread of resistant strains. A study is currently underway to assess the value of a global approach combining screening and additional precautions in patients with P. aeruginosa.In conclusion, this study confirms the effectiveness of some preventive measures while underlining the limitations of other approaches. However it does not promote a particular strategy. Because in terms of BMR, it is necessary to define global and cross-sectorial strategies which go beyond the health care facilities
Tsofack, Serges Prosper. "Identification des partenaires de la protéines YB-1 impliqués au niveau de la chimiorésistance des composés à base de platine et mise au point des nouvelles cibles thérapeutiques". Doctoral thesis, Université Laval, 2015. http://hdl.handle.net/20.500.11794/25837.
Pełny tekst źródłaYB-1 (Y-Box-binding Protein 1) is a multifunctional protein involved in several cellular processes including transcription, translation and DNA repair. YB-1 is important for late-stage embryonic development and belongs to the family of DNA/RNA-binding proteins with an evolutionarily ancient conserved Cold Shock Domain (CSD). YB-1 is overexpressed in many malignant tissues and plays an important role in the development of cancer. Many studies reported that high expression of YB-1 protein is associated with a worse prognosis in cancer patients. Moreover, an overexpression of YB-1 protein in breast, colorectal and ovarian cancer cell lines induced chemoresistance to platinum agents. YB-1 protein is a good therapeutic target to counteract platinum resistance in cancer. Different strategies for novel therapeutic approaches targeting YB-1 protein were used to prevent and treat people with cancer. The use of YB-1 as a therapeutic targets is still a big challenge in research and its multifunctional properties should be taken into consideration when developing a new therapy against YB-1. The goals of this project are to identify YB-1-interacting proteins required for platinum agents resistance in cancer cell lines and to develop a potential therapeutic target to treat cancers. During this study, NONO and RALY proteins were identified as new partners of YB-1 protein in colorectal cancer cell lines. We proved that NONO and RALY are significant potential target to counteract oxaliplatin resistance in colorectal cancers including tumors overexpressing the YB-1 protein. In addition, we found RPS4X protein as new a partner of YB-1 involved in cisplatin resistance in beast and ovarian cancers. These results suggest that the RPS4X protein is a significant potential target to counteract cisplatin resistance in breast and ovarian cancers. Also, we have established that RPS4X is a new promising prognostic marker for patients with high-grade serous ovarian cancer. More importantly, RPS4X is shown to be predictive of cisplatin response. RPS4X could thus be useful when selecting the first line therapies for patients with breast and ovarian cancer.
Fartouna-Bellakhal, Mouna. "Distribution spatiale des kystes de résistance des Dinoflagellés au niveau du sédiment superficiel de la lagune de Bizerte : cas de l’espèce invasive Alexandrium pacificum R.W. Litaker, 2014". Thesis, Besançon, 2016. http://www.theses.fr/2016BESA2081/document.
Pełny tekst źródłaThe ballast water discharges in Bizerte harbor and shellfish aquaculture farms in Bizerte lagoon can be potentials sources with an interest in the introduction of harmful species, especially those that are potentially toxic like A. pacificum, A. pseudogonyaulax, A.minutum, A.affine and Polysphaeridium zoharyi, without neglecting the role of currents in the distribution of cysts. The study of the vessel traffics for 7 years before our prospection in Bizerte harbour have showing that the percentage of vessels coming from the Pacific road is around 14%. In order to identify species of Dinoflagellates producing resting cysts incriminated on potentially toxic blooms, a high spatial resolution sampling of the surface sediment for the identification and counting of resistance cysts was carried out to estimate the cyst density based on sedimentary characteristics, water content, organic matter, granulometry, abundance of vegetative forms and environmental factors. This study allowed the identification of 48 morphotypes of dinoflagellate cysts, mainly dominated by Brigantidinium simplex, Votadinum spinosum, Alexandrium pacificum, Alexandrium pseudogonyaulax and Lingulodinum machaerophorum. The density of cysts ranged from 1276 to 20126 cysts g-1 dry sediment. Significant differences between cyst distributions were recorded, which enabled us to distinguish two areas in the Bizerte lagoon. Particular attention was given to the complex Alexandrium tamarense (HABs). In addition, morphological examination and ribotyping of vegetative cells obtained from microalgal cultures following extraction process, isolation of resistance cysts from sediment, and their germination led to the production of monospecific culture: ABZ1 characterized by a μ (growth rate) = 0.33 day-1 and a generation time T = 2.1 day. These reviews have confirmed the newly identified genus and species in the Mediterranean sea and mentioned specifically in the lagoon of Bizerte: Alexandrium pacificum. The toxin profile obtained from an extract of ABZ1 culture in exponential phase revealed the presence of N-sulfocarbamoyl toxin C1 (9.82 pg toxin Cell-1), the GTX6 (3.26 pg toxin Cell-1), carbamoyl and the Neo-STX toxin (0.38 pg cell toxin-1), representing 2.8% of total toxins of this strain.A correlation between the abundance of cysts of Alexandrium pacificum and water percentage well as organic matter was found. Moreover, sediment fraction <63μm proved potentially favorable to initiate Alexandrium pacificum blooms in Bizerte lagoon. A significant difference in the cyst distribution diagram was shown, highlighting a zoning of the lagoon with a greater abundance in shellfish farm areas
Avenot, Hervé. "Variabilité au sein de l'espèce fongique phytopathogène Alternaria brassicicola : analyse au niveau d'un marqueur sélectionné de type résistance aux fongicides et de marqueurs neutres de type microsatellites". Angers, 2005. http://www.theses.fr/2005ANGE0033.
Pełny tekst źródłaAlternaria brassicicola causes blackspot disease of crucifers worldwide. This disease is seed-borne and responsible for important yield losses. Field isolates of A. Brassicicola highly resistant to dicarboximide and phenylpyrroles fungicides have been identified. These isolates are still pathogenic to host plants and most of them are more sensitive to osmotic stress than wild type strains. To elucidate the molecular basis of the osmosensitive and dicarboximide/phenylpyrrole-resistant phenotypes, an osmosensing histidine kinase gene AbNIK1 was isolated from a fungicide-sensitive isolate and its sequence compared with corresponding sequences from fungicide-resistant isolates. All the fungicide-resistant strains displaying a osmosensitive phenotype were found to have null mutations in the AbNIK1 gene. To investigate the effects of AbNIK1 null mutations on their fitness, these strains were inoculated on radish under field conditions. Quality controls of produced seeds revealed that null mutants are strongly affected in their competitivity towards wild type strains in the absence of selective pressure. In parallel, the genetic diversity within the species A. Brassicicola was estimated. Twelve polymorphic microsatellite loci were identified and used to analyze a population of strains with various geographic origins. In agreement with the lifestyle of this fungus (absence of sexual reproduction and seed transmission) a relatively weak polymorphism (3. 5 alleles per locus) and an absence of population structuration were observed
Harmel, Élodie. "Rôle et régulation de la protéine kinase AMPK au niveau intestinal". Phd thesis, Université Claude Bernard - Lyon I, 2012. http://tel.archives-ouvertes.fr/tel-00934093.
Pełny tekst źródłaBerthou, Flavien. "La désensibilisation croisée des voies de signalisation de la leptine et de l'insuline au niveau central : lien possible entre leptino- (obésité) et insulino-résistance (diabète de type 2)". Paris 11, 2009. http://www.theses.fr/2009PA11T108.
Pełny tekst źródłaKerangart, Stéphane. "Convergences évolutives et différenciations verticales chez les Escherichia coli producteurs de Shiga-toxines (STEC) pathogènes révélées par analyse de leurs propriétés métaboliques et de résistance aux antimicrobiens". Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE1091.
Pełny tekst źródłaShiga-toxin producing Escherichia coli (STEC) are major human pathogenic bacteria. These bacteria can cause hemorrhagic diarrheal diseases and Haemolytic and Uremic Syndromes. A risk assessment of more than 200 STEC serotypes has been performed using molecular markers of virulence and epidemiological datasets. However, virulence is not always associated with known or sufficiently described factors, questioning the reliability of such classifications. The hypothesis of this PhD work was that risk levels associated with STEC strains should be related not only to virulence specificities but also other metabolic properties such as a specialization for particular C-sources or resistances towards various antimicrobials. Few data were available on STEC physiology, with the exception of datasets regarding the metabolic properties exploited for the development of specific culture media. The aim of this work was to improve knowledge on STEC metabolic capacities and investigate relationships with their respective risk level. This work was divided into three parts: (i) a study of potassium tellurite (K2TeO3) resistance, an oxyanion highly toxic for cell membranes, (ii) a study of carbon metabolic profiles, and (iii) an exhaustive study of antibiotic and other antimicrobial resistances. A great variability in K2TeO3 resistance profiles was observed, as well as a phenomenon leading to the emergence of significant numbers of spontaneous mutants. The use of tellurite for STEC detection was found to lead to an underestimation of their prevalence in food products. Specific metabolic profiles including resistance to certain antimicrobial substances were found related to STEC classifications into risk levels. These data allowed us to observe specific vertical evolutions of these phenotypes per serogroup but some intergroup evolutionary convergences were also observed. These datasets led to the proposal of novel STEC detection and identification schemes. These schemes can be used by risk assessment managers for a better appreciation of STEC risk hazards among food and environmental samples
Pelletier, Daisy. "Les facteurs cognitifs, textuels et contextuels qui influencent la compréhension d'une nouvelle littéraire résistante par des adolescents de 13 à 17 ans". Master's thesis, Université Laval, 2017. http://hdl.handle.net/20.500.11794/28273.
Pełny tekst źródłaAmine, Hamza. "La microalgue Odontella aurita prévient l'insulino-résistance et l'inflammation hépatiques induites par un régime hyper-lipidique : mise en évidence des mécanismes insulino-sensibilisateurs des acides gras polyinsaturés omega-3 au niveau neuronal". Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS050/document.
Pełny tekst źródłaThe metabolic syndrome is characterized by dyslipidemia, insulin resistance, abdominal obesity and hypertension, which are related to an elevated risk for type 2 diabetes mellitus. Omega-3 polyunsaturated fatty acids have extensive biological effects and modulate the risk factors for metabolic syndrome via multiple mechanisms. However their impact on insulin resistance and type 2 diabetes are still unknown.In the current study, we report that Odontella aurita, a microalga rich in the omega-3 polyunsaturated fatty acid eicosapentaenoic acid (EPA), prevents High saturated fat diet induced insulin resistance and inflammation in the liver of Wistar rats. High fat diet (HFD), given for 8 weeks, increased plasma insulin levels associated with the down-regulation of insulin receptor (IR) and the impairment of insulin-dependent IR phosphorylation. Furthermore, HFD increased toll-like receptor 4 (TLR4) expressions. Indeed, we have recently reported that TLR4 is implicated in resistin-induced inflammation and insulin resistance in the hypothalamus (Benomar et al, 2013). We also show that TLR4 up-regulation is concomitant with the activation of c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38). Importantly, Odontella aurita enriched HFD (HFOA, 12%) normalized body weight and plasma insulin levels, and restores IR expression at both protein and mRNA levels. In addition, HFAO improves insulin responsiveness as estimated by in vitro phosphorylation of hepatic plasma membrane IR. Furthermore, HFOA decreased TLR4 expression and JNK /p38 phosphorylation. In conclusion, we demonstrate, for the first time to our knowledge, that omega-3 fatty acids brought by Ondontella aurita overcomes HFD-induced insulin resistance through the inhibition of TLR4/JNK/p38 MAP kinase signaling pathways.To further explore the molecular process underlying the activation of TLR4 by fatty acids, we aim to decipher the mechanisms implicated in the regulation of TLR4 expression. For this purpose, human neuroblastoma cells (SHSY-5Y) were exposed during 4h to either palmitic acid (a saturated fatty acid) or the omega-3 polyunsaturated fatty acid docosahexaenoic acid (DHA). Cells were then treated with resistin. Firstly we analyzed the effect of resistin, palmitic acid and DHA on inflammation markers. We show that only resistin was able to activate NF-κB and to increase the phosphorylation of Akt and p38 MAPK. However, palmitic acid pretreatment increases the expression of inflammatory cytokines (IL-6 and TNF-α), similar to resistin. Interestingly, DHA pretreatment suppresses palmitic acid and resistin induced up-regulation of IL-6 and TNF-α. Secondly, we studied the possible synergistic interaction between resistin and palmitic acid on TLR-4 expression. We show that palmitic acid pretreatment increases TLR4 expression, at both protein and mRNA levels, while DHA pretreatment had no effect. Importantly, palmitic acid pretreatment potentiates resistin effects. In conclusion, we show for the first time, to our knowledge, that palmitic acid induces TLR4 expression and this leads to the amplification of resistin effects promoting then insulin resistance at the neuronal level.Taken together, these results demonstrate that omega-3 fatty acids prevent saturated fat-induced inflammation and insulin resistance through resistin/TLR4 signaling thereby preventing insulin resistance
Zenati, Ali. "Gestion haut niveau et suivi en ligne de l'état de santé des batteries lithium-ion". Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0391/document.
Pełny tekst źródłaLithium-ion batteries are considered nowadays as the optimal issue for the energy storage systems, it is mainly due to their high energy and power density. Their performances, lifetime, and reliability are related and depend on the operating conditions such as the temperature and requested current by the application. And in order to track the evolution of the ageing of the battery, the determination of its State-Of-Health -SOH- is a major function to consider. This thesis presents both methodologies and techniques developed for the management of the lifetime of lithium-ion battery, and more particularly the assessment of its state-of-health, based on its own main parameters which are the capacity and the ohmic resistance. This approach allows to switch from a static SOH (based on a predefined ageing model, which take into account the calendar and cycling ageing of the battery, according to some characteristics such as the temperature and the courant of the battery tracked in real time) to a dynamic SOH (self-adaptive) using an online assessment of the previous parameters according to the operating conditions. The first chapter is an overview about the lithium-ion technology: characteristics, performances, cell design, choice and nature of the electrodes... The operating principle with the general equations are also developed. The second chapter is a state of the art of the lifetime prediction methodologies with the different kinds of classification of models and prediction techniques. Then in the third chapter, we will discuss our methodologies and the developed techniques, such as the use of statistics, fuzzy logic and rules of ageing to assess a dynamic state of health of the battery, which not only does take into account the static SOH (calendar and cycling ageing), but also considers the evolution of the ohmic resistance and the capacity of the battery, depending on the time and the operating conditions. This allows taking into consideration unlikely phenomena. Finally, in the last chapter, we will expose obtained results from validation tests. These tests were done under a power electrical testbench and a rapid prototyping testbench with real cells
Rande, Hugo. "Effets du niveau de pollution métallique et des stratégies fonctionnelles sur les types d’effets en jeu dans les interactions entre plantes au niveau d’anciens sites miniers des Pyrénées". Electronic Thesis or Diss., Bordeaux, 2024. http://www.theses.fr/2024BORD0032.
Pełny tekst źródłaPlant-plant interactions have been overlooked in metal/metalloids-impacted environments and are likely driven by several factors whose influence is barely known. First, plant-plant interactions depend on the level of metal pollution, but also on the functional plant strategies of the interacting plants. Furthermore, plants can have several type of effects on their immediate environment, acting at different timescales. Plants canopy and roots have an instantaneous influence on the microclimate and available resources in their immediate vicinity. Then, during a growing season, the production of litter and its decomposition beneath their canopy can influence soil chemical and physical properties. In the longer term, when this cycle of litter production/decomposition is repeated over the years, the dynamics of the organic matter will influence soil conditions even more. In this thesis, our main objective was to delineate these effects, and to understand how plant functional strategies can influence these various effects along metal pollution gradients. We studied these effects during three consecutive years (from 2020 to 2022) in a former mining valley in the French Pyrenees (Sentein, Ariège, France). In this area, we studied interactions between plants using observational and target transplantation methods controlling for the presence of plant canopy and/or plant litter, in three study sites: a slag heap with homogeneous pollution and two mine tailings areas with heterogeneous pollution creating a gradient of pollution. Along these gradients, short-term canopy and root-uptake effects followed the Stress Gradient Hypothesis, switching from competition to facilitation as pollution increased. This facilitation was stronger when the species producing the effect were acquisitive (in relation with soil resources and the Leaf Economic Spectrum), and benefits more the low metal-tolerant plants. These positive effects were mainly due to the improvement of micro-climatic conditions during hot and dry episodes in summer. Concerning the effects linked to litter production and decomposition, negative effects on target plants were found, suggesting the so-called “elemental allelopathic” effects, in relation with the high concentration of metallic elements in the decomposing litter. These negative litter effects were more important in the least polluted environments, where metal-accumulating metallophyte plants (which have high concentration of metals in their leaves) and less metal-tolerant plants interacts. They were particularly marked for targets sensitive to metal pollution. The results of this thesis give important perspectives regarding the use of facilitation for the phyto-management of metals/metalloids-polluted environments, given that the functional strategies of interacting plants and the level of pollution involved are explicitly considered. Additionnaly, the results obtained during the 2022 heatwave provide useful insights regarding the expected evolution of the different effects driving plant interactions in metalliferous ecosystems in a climate change context
El, Merabi Bassel. "Comportement mécanique des joints cohésifs de béton-granite au niveau de l'interface barrage-fondation : influence géométrique et mécanique des aspérités". Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAI008/document.
Pełny tekst źródłaThe shear strength of the concrete-rock interface is a key factor in assessing the stability against sliding of concrete dams founded on rock. While several studies have shown that both surface roughness and the initial cohesion contribute to the shear strength, most of the recommendations for the stability assessment of dams propose conventional values for the mechanical parameters of the dam-foundation interface (i.e. friction angle and cohesion). Moreover, most of the criteria proposed in the literature in order to determine the shear strength of rough joints are based on direct shear tests conducted on joints without initial bonding. Another major difficulty lies in the quantification of surface roughness by means of an objective parameter able to describe the three dimensional aspect of surface roughness as well as the anisotropy observed experimentally. In this context, one of the primary objectives of this thesis is to better understand the shear behavior of bonded rough joints and to relate the shear strength to the morphological parameters of the concrete-rock interface.Due to the complexity of the shear behavior of bonded joints and because few studies have been carried out on cohesive samples, it was decided to perform several experimental campaigns on different types of geometries with an increasingly complex roughness (smooth, bush-hammered, tooth-shaped asperities and natural surfaces). For this purpose, more than thirty direct shear tests were performed on bonded samples at three levels of normal stress. The influence of the shear displacement rate on the shear behavior of joints was also investigated. Prior to the shear tests, a morphological tool was developed in order to provide an objective quantification of surface roughness based on surface measurements obtained with a laser profilometer.Based on the shear test results, two different shear behaviors were observed for the natural joints according to surface roughness and the level of normal stress. Thus, an analytical expression was proposed in order to quantify the contribution from the different modes of failure to the shear strength. It is shown that this expression is able to well predict the shear strength of natural joints. Furthermore, a new roughness parameter was proposed in order to quantify the morphology of natural joints and to account for the different levels of surface roughness involved in the shearing mechanism. This parameter was found to be well correlated with the shear strength of joints sheared at a normal stress less than 0.6MPa.On the other hand, numerical simulations of the direct shear tests were conducted by using a 3D finite element code and by incorporating the reconstructed joint surface obtained from the laser profilometer. Two different models were used: a cohesive-frictional model for the pre-peak phase and a contact law for modeling the residual shear behavior. The mechanical parameters of the concrete-granite interface were obtained from the results of the experimental campaigns on bush-hammered samples. The comparison between the numerical results and the experimental data showed a good agreement in the residual phase. The use of a cohesive-friction model, on the other hand, allowed to mimic the overall shape of the shear stress curve
Carbillet, Malherbe Jeffrey. "Influence des caractéristiques environnementales et individuelles sur le niveau de stress basal, et conséquences, chez un grand mammifère, le chevreuil Capreolus capreolus". Thesis, Toulouse 3, 2019. http://www.theses.fr/2019TOU30284.
Pełny tekst źródłaOver the last century, extreme climatic events and landscape modifications due to anthropogenic activities have dramatically increased. These rapid and unpredictable changes in the environment are new selective pressures for wild animals, and can threaten their survival and affect population dynamics. Understanding how wild animals cope with these perturbations and their consequences on life history traits and population dynamics is a necessary step to evaluate their evolutionary potential in a changing world. An important mechanism for adaptation to environmental changes is the stress response, which consist of a suite of physiological and behavioural responses that aim to maximise immediate survival. One of the main physiological pathways of the stress response is the hypothalamic-pituitary-adrenal axis, which triggers the secretion of glucocorticoid hormones. Because these hormones drive the mobilisation and distribution of energy, they underlie trade-offs between key functions such as immunity and reproduction. However, not all individuals respond in the same way to stressful situations, resulting in large among-individual differences. In addition, the natural environment not only offers a great deal of variability in stressors, but also means of responding to stress (e.g. the presence of shelters). In turn, the diversity of stress patterns depends on a complex combination of environmental variables and individual factors. The general aim of my thesis was to understand the determinants of the great among-individual differences in baseline stress levels, and to identify some consequences in a long-lived mammal, the European roe deer. The study analysed several measures of stress and their links with environmental and individual characteristics, and combined observation in three wild population and experimentation in captive roe deer. Using an integrative approach, I found that proxies of stress level (N:L ratio and faecal cortisol metabolites [FCMs]) were moderately repeatable and weakly associated with behavioural response to capture. In two populations, stress levels were higher during years of poor resources quality. I also found that FCMs of roe deer increased with proximity to human infrastructures, but this effect was buffered by behavioural adjustments such as using forest as refuge and adopting nocturnal activity patterns. Secondly, I showed that environmental and behavioural characteristics were already determinant of baseline stress levels since the first weeks of life. Salivary cortisol was higher in fawns when they were closer to anthropogenic structures and exhibited proactive behaviour. Although fawn phenotype may also be shaped by maternal stress, the small data set of 30 mother-fawns pairs did not enable to show such as relationship. Finally, I showed that the co-variation between immunity and FCMs, depended on individual and environmental characteristics. In a poor environment, high FCMs were related to a low immunity, both for innate and adaptive arms.[...]
Vandenhende, Marie-Anne. "Echecs virologiques au sein de cohortes hospitalières de patients adultes infectés par le VIH : apport de l'ultra-deep sequencing et étude des charges virales de faible niveau persistantes". Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0143/document.
Pełny tekst źródłaThe goal of antiretroviral therapy (ART) is to reach undetectable plasma HIV viral load in orderto reduce HIV-related morbidity and mortality.The presence of ART-resistant virus can compromise the efficiency of these treatments,resulting in virological failure (VF). Standard genotyping by Sanger sequencing (SS) usedcurrently in clinical practice cannot detect low-frequency viral variants harbouring drugresistance associated mutations (DRM) representing less than 20% of the viral population. Inour study, the use of ultra-deep sequencing (UDS) allowed us to detect 1.4-fold more DRMsbefore ART and 1.3-fold more DRMs at VF compared to SS, confirming the high sensitivity ofUDS for the detection of DRMs. The low-frequency DMRs detected only by UDS modified thegenotypic resistance of the virus to the prescribed treatment for 4% of the patients before ARTinitiation and for 21% of the patients at VF.The impact of persistent low-level viremia (LLV) between 50 and 200 copies/ml (LLV50-200)remains uncertain due to the lack of controlled comparison data. In our cohort studies (ANRSCO3 and ART-CC cohorts), 4-9% of HIV-infected patients experienced at least one episode ofLLV50-200. LLV50-200 was strongly associated with a twice higher risk of VF>200copies/ml,independently of the duration of LLV, the history of treatment or the type of ART regimen atLLV (NNRTI or PI-based regimens). LLV was not associated with AIDS event or death witha median follow-up of only 3 years
Zenati, Ali. "Gestion haut niveau et suivi en ligne de l'état de santé des batteries lithium-ion". Electronic Thesis or Diss., Université de Lorraine, 2012. http://www.theses.fr/2012LORR0391.
Pełny tekst źródłaLithium-ion batteries are considered nowadays as the optimal issue for the energy storage systems, it is mainly due to their high energy and power density. Their performances, lifetime, and reliability are related and depend on the operating conditions such as the temperature and requested current by the application. And in order to track the evolution of the ageing of the battery, the determination of its State-Of-Health -SOH- is a major function to consider. This thesis presents both methodologies and techniques developed for the management of the lifetime of lithium-ion battery, and more particularly the assessment of its state-of-health, based on its own main parameters which are the capacity and the ohmic resistance. This approach allows to switch from a static SOH (based on a predefined ageing model, which take into account the calendar and cycling ageing of the battery, according to some characteristics such as the temperature and the courant of the battery tracked in real time) to a dynamic SOH (self-adaptive) using an online assessment of the previous parameters according to the operating conditions. The first chapter is an overview about the lithium-ion technology: characteristics, performances, cell design, choice and nature of the electrodes... The operating principle with the general equations are also developed. The second chapter is a state of the art of the lifetime prediction methodologies with the different kinds of classification of models and prediction techniques. Then in the third chapter, we will discuss our methodologies and the developed techniques, such as the use of statistics, fuzzy logic and rules of ageing to assess a dynamic state of health of the battery, which not only does take into account the static SOH (calendar and cycling ageing), but also considers the evolution of the ohmic resistance and the capacity of the battery, depending on the time and the operating conditions. This allows taking into consideration unlikely phenomena. Finally, in the last chapter, we will expose obtained results from validation tests. These tests were done under a power electrical testbench and a rapid prototyping testbench with real cells
Sadio, Malick. "Etude des mécanismes de régulation de la voie de Signalisation de TLR4 par les microARN au niveau des épithéliums". Thesis, Sorbonne Paris Cité, 2017. http://www.theses.fr/2017USPCC286.
Pełny tekst źródłaEpithelial cells play a key role in the establishment and the maintenance of homeostasis, but also in the defense against pathogens, particulary via the receptors of innate immunity, such as the Toll-like receptor (TLR) 4. Indeed, the stimulation of this receptor by its ligand, the lypopolysaccharide (LPS), the major constituent of the wall of Gram-negative bacteria, induces cellular activation and production of inflammatory mediators, such as cytokines and pro-inflammatory chemokines KC and MIP-2. In this work, I studied the mechanisms of regulation of the signaling pathway of the TLR4 receptor in epithelial cells, specially via microRNAs, small non-coding RNAs which can regulate extremelys rapidly and efficiently the expression of genes. In a first part, using an immortalized renal collector tubule cell line, primary cultures of TC cells microdissected from transgenic mouse kidneys, as well as a mouse model of ascending UTI, CsA induces the expression of the Let-7i microRNA, which targets TLR4 and therefore inhibits the LPS induced cell activation. In a second part, using an immortalized intestinal epithelial cell line as well as a mouse model of Citrobacter rodentium digestive tract infection, we were able to show that IL-22 induces expression of miR-763 which, by potentiating the degradation of the kinase IRAK1, a key kinase of the TLR4 signaling pathway, induces an inhibition of the TLR4 signaling pathway in the intestinal epithelial cells. My thesis work has permitted to provide lines of evidence in the involvement of specific microRNAs in the regulation of the TLR4 signaling pathway in the epithelial cells, suggesting that the use of synthetic anti-miR could be effective to treat certain inflammatory or infectious diseases
Ringeard, Mathieu. "TRBP recrute une 2’O-méthyltransférase au niveau de l’ARN du Virus de l’Immunodéficience Humaine de type 1 (VIH-1) : mécanisme d’échappement au système immunitaire inné". Thesis, Montpellier 1, 2013. http://www.theses.fr/2013MON1T020.
Pełny tekst źródłaTRBP (TAR RNA Binding Protein) is a cellular RNA binding protein that facilitates the replication of Human Immunodeficiency Virus type 1 (HIV-1). Isolated for its ability to bind HIV-1 TAR sequence present at the 5' end of all HIV-1 RNA, TRBP promotes HIV-1 replication at a post-transcriptional level by counteracting the antiviral activity of the protein kinase R (PKR).To gain more insight on how TRBP enhances HIV-1 replication, TRBP associated factors were purified using tandem immunoaffinity purification and identified by mass spectrometry. In addition to already known associated factors, a new protein with a putative RNA 2'-O-methyltransferase activity (2'OMTases) was copurified: FTSJ3. In higher eukaryotes, cellular mRNA are methylated on 2'-O ribose position on the first (Cap 1) and second nucleotide (Cap 2). This capping provides a molecular signature for the discrimination of endogenous versus exogenous mRNA. In the cell, MDA5, a cytoplasmic sensor, recognizes exogenous uncapped RNA and activate type I interferons (IFNs) production to establish an antiviral state. To evade innate immune response, some viruses have evolved mechanisms to mimics cap 1/2.HIV-1 does not encode a 2'O-MTase activity. However, owing to its interaction with TRBP, FTSJ3 is recruited at the 5' end of the viral genome and methylates TAR RNA in vitro. When capped by FTSJ3, TAR does not induce type I IFNs anymore when transfected in monocytic cell line U937. Conversely, HIV-1 viruses produced in FTSJ3 knock-down cells triggers type I IFNs expression through MDA5 sensing. This virus is attenuated, expressed in low amounts because of a block at the level of HIV-1 nuclear import. This study shows that FTSJ3 is recruited to HIV-1 5' end TAR sequence by TRBP and facilitates HIV-1 replication. HIV-1 RNA capping allows HIV-1 escape from MDA5 sensing and type I IFN induction. This study highlights a new way of HIV-1 escape from innate immune system
Dubecq, Simon. "Stress-Test Exercises and the Pricing of Very Long-Term Bonds". Phd thesis, Université Paris Dauphine - Paris IX, 2013. http://tel.archives-ouvertes.fr/tel-00871760.
Pełny tekst źródłaFournier, Chantal. "Étude de la P-glycoprotéine : effet des coumarins et du niveau d'interaction entre la P-gp et la cavéoline-1 sur les activités associées à la P-gp". Mémoire, 2007. http://www.archipel.uqam.ca/863/1/M9791.pdf.
Pełny tekst źródłaBascou, Joseph. "Analyse biomécanique pour la compréhension et l'amélioration du fauteuil roulant dans son application au tennis de haut niveau". Phd thesis, 2012. http://pastel.archives-ouvertes.fr/pastel-00831253.
Pełny tekst źródłaHarmel, Elodie. "Rôle et régulation de la protéine kinase AMPK au niveau intestinal". Thèse, 2012. http://hdl.handle.net/1866/8904.
Pełny tekst źródłaPhysiopathology of type II Diabetes is characterized by severe metabolic abnormalities such as hyperglycemia and dyslipidemia also implicated in development of cardiovascular diseases. Impaired AMPK activity in tissues such as skeletal muscle and liver is associated with these metabolic disorders whereas its pharmacologic activation is able to restore such abnormalities. Nevertheless, tissue-specific heterotrimeric αβγ AMPK likely confers distinct roles and regulation that remain unexplored in intestine, an organ promoting enhanced nutrients absorption in type II diabetes situation. This study demonstrates α1β2γ1 AMPK complex preponderance in intestinal Caco-2 cells whose α1 subunit role is to regulate ACC enzyme responsible of fatty acid synthesis. Unlike in the liver, AMPK doesn’t regulate HMG-CoA reductase enzyme implicated in cholesterol synthesis. AMPK activation mimics insulin effect by reducing intestinal glucose and lipids absorption whereas its alteration in insulin-resistance situation (e.g.: induced by 4-HHE in Caco-2 cell model or in Psammomys obesus animal model) enhances glucose and lipids absorption which could exacerbate postprandial hyperglycemia and dyslipidemia associated to type II diabetes. Thus, AMPK at the intestinal level could be a potential therapeutic target in prevention and treatment of type II diabetes.
réalisé en cotutelle avec l'Université Claude Bernard Lyon 1
Mohseni-Masouleh, Sara. "Identification de nouveaux gènes CBF chez le blé hexaploïde Norstar et identification de polymorphismes au niveau de gènes CBF chez des cultivars de blé possédant des capacités différentes d'acclimatation au froid". Mémoire, 2012. http://www.archipel.uqam.ca/5457/1/M12574.pdf.
Pełny tekst źródłaCharron, Vanessa. "Hijab et sport : représentations et auto-représentations des athlètes hijabis de haut niveau". Thèse, 2016. http://hdl.handle.net/1866/18841.
Pełny tekst źródłaThe inspiration for this master's thesis comes from the third item of the rule 50 in the Olympic Charter : No kind of demonstration or political, religious or racial propaganda is permitted in any Olympic sites, venues or other Olympic areas. (CIO 2013: 96) This rule is not only restrictive for athletes wearing the hijab, but it is also used to discredit them. Why this constraint? Should not sport be accessible for all, given all the benefits it offers? Taking the conceptual basis of gendered islamophobia concepts (Zine 2006), embodied intersectionality (Mirza 2012) and nationalism (Balibar 1997 [1988]) as well as the racialized regime of representation (Hall 1997) as analytical basis, this master's thesis offers a cross-reading of three types of discourses : the media discourses on the hijab in sports and on the women who wear it ; the discourses held by the hijabis athletes themselves ; and public discourses, including fans. Through the study of the "public personality" of four hijabis athletes as built on their Facebook page, all of the top athletes, and the exchanges that these have had on this platform with their audience, this study shows alternative discourses to those of the dominant medias who widely see the hijab in sports as a problem. These include the positive role that these athletes play in promoting sports and physical activity among Muslim women, especially those wearing the hijab.
Sabourin-Poirier, Catherine. "Étude du niveau de B Lymphocyte Stimulator (BLyS) et de son impact sur les lymphocytes B en relation avec l’infection et la résistance au virus d’immunodéficience humaine (VIH) chez des travailleuses du sexe au Bénin". Thèse, 2016. http://hdl.handle.net/1866/16275.
Pełny tekst źródłaHIV infection leads to B cell dysregulations that disrupt efficient immune responses. Detected early after infection, these dysregulations are lasting, are not totally resolved by therapy and often lead to auto-immune defects. We have shown that excess BLyS in plasma and on the surface of blood dendritic cells (DC) of HIV-infected progressors coincides with B cell dysregulation and increased frequency of “precursor” innate marginal zone (MZ)-like B cells. In contrast, BLyS levels were normal in elite-controllers and frequency of precursor MZ-like B cells was unaltered. Instead, percentages of MZ-like B-cells presenting a more “mature” profile were decreased in the blood of these individuals, suggesting peripheral recruitment of these cells could be beneficial to the control of disease progression. Based on this, we hypothesize that control of BLyS status and innate B cells could be relevant to the understanding of natural immunity to HIV. We previously established an ongoing cohort of heavily HIV-exposed female commercial sex workers (CSWs) in Cotonou (Benin) and identified individuals who remain HIV-uninfected after several years of active prostitution. Herein, we have measured BLyS levels in the blood and cervico-vaginal lavages (CVLs) of HIV-uninfected CSWs and have compared them to those of HIV-infected CSWs and control uninfected non-CSWs. We found that BLyS levels in the blood and CVLs of HIV-uninfected CSWs were lower when compared to HIV-infected CSWs and even to controls. BLyS surface expression on T-cells, monocytes, and DC of HIV-uninfected CSWs was increased, but to a significantly lower extent than those measured in HIV-infected CSWs, albeit higher than controls. In HIV-infected CSWs, high BLyS levels were concomitant with a dysregulated blood B-cell compartment, characterized by hyperglobulinemia, increased frequency of populations presenting immature and/or innate profiles and a higher proportion of IgG+ than IgA+ plasmablasts. In contrast, contained BLyS levels in the blood of HIV-uninfected CSWs coincided with a rather preserved B-cell compartment, which reveals that “mature” MZ-like B-cells could be involved in natural immunity against HIV. These results highlight the importance of a better understanding of B cell populations and BLyS in the context of HIV resistance.
Lanteigne, Marie-Eve. "Influence de la variété de laitue (Lactuca sativa) sur le puceron (Nasonovia ribisnigri) et le parasitoïde (Aphidius ervi) dans le contexte d’une relation tritrophique". Thèse, 2014. http://hdl.handle.net/1866/10598.
Pełny tekst źródłaNew cultivars of commercialized lettuce (Lactuca sativa L.) with an improved resistance to pests are now available. The objective of this study was to examine the impacts of lettuce resistance on the lettuce aphid, Nasonovia ribisnigri (Mosley) (Hemiptera: Aphididae) and one of its parasitoids, Aphidius ervi Haliday (Hymenoptera: Braconidae). Lettuce resistance negatively affects aphid fitness by: increasing its mortality and developmental time and decreasing its fecundity, size and mass. This impact on aphid fitness also negatively impacts the parasitoid by decreasing its proportion of emergence, the size and mass of adults and decreasing fecundity of females. Female parasitoids estimate hosts quality in an absolute way as they can discriminate between high and low quality hosts, without previous experience. High quality host acceptation remains constant when hosts are successively offered to a female, indicating that the female can adequately estimate host value without experience. However, this absolute estimate of host quality is modified through experience as the female changes her patch exploitation according to the quality of the patches she encounters. When low quality hosts are successively offered, female acceptation increases. Accepting low quality hosts for oviposition can be preferable to the risk of not using all her eggs. The two strategies combined, using an absolute and a relative estimation, could lead to optimal patch exploitation by A. ervi.