WorldCat Identities

École doctorale Sciences de la vie et de la santé (Bordeaux)

Overview
Works: 840 works in 858 publications in 2 languages and 862 library holdings
Roles: Other, Degree grantor, 996
Publication Timeline
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Most widely held works by École doctorale Sciences de la vie et de la santé (Bordeaux)
Etude de la régulation glutamate dépendante de la mobilité des récepteurs AMPA et de son rôle physiologique by Audrey Constals( Book )

2 editions published in 2013 in French and held by 3 WorldCat member libraries worldwide

AMPA receptors (AMPAR) are ionotropic glutamate receptors which are responsible for the vast majority of fast excitatory synaptic currents in fast transmission. Upon release of glutamate, AMPAR undergo three main conformational states: pore closed/agonist unbound, pore open/agonist bound and pore closed/agonist bound. Controlling the number of AMPAR and their organization in the synapse, through a combination of lateral diffusion and endo/exocytosis, is essential to regulate the intensity of synaptic transmission. The interactions between proteins of the post-synaptic density and accessory receptor proteins regulate the distribution of receptors, controlling their number and organization in the post-synapse. During my PhD, I studied the impact of AMPAR activation on their mobility and organization in the post-synapse. Indeed, the binding of glutamate to AMPAR and their following desensitization lead to major structural changes on the receptor which impacts on their interactions with scaffolding proteins and accessory proteins. The impact of such modifications on the lateral diffusion and sub-synaptic organization of AMPAR was not known yet. My findings show a mobilization of synaptic AMPAR following their activation by glutamate. At the molecular level, I suggest that the transition from the activated state to the desensitized state of AMPAR leads to a change in affinity of the receptor for their partner protein: Stargazin. This glutamate dependent regulation of AMPAR diffusion participates in maintaining the fidelity of fast synaptic transmission
Etude de l'atténuation scanographique de la paroi bronchique dans l'imagerie de l'inflammation et du remodelage des voies aériennes by Mathieu Lederlin( Book )

2 editions published in 2011 in French and held by 3 WorldCat member libraries worldwide

Asthma and chronic obstructive pulmonary disease (COPD) are frequent conditions characterized by two main pathological changes: bronchial inflammation and remodelling. Pathological examination requires invasive biopsy, which is rarely performed in routine. Therefore there is a great interest in developing non-invasive methods that would lead to more precise phenotyping of patients and the development of new targeted treatments. Computed tomography (CT) can provide a quantitative morphometry-based analysis of the airways. These morphometric parameters have been shown to correlate with functional obstruction but are poorly used in routine practice due to their lack of standardisation. The aim of our studies was to investigate the value of CT attenuation-based parameters in humans and animals. In asthma and COPD, we have shown that the wall attenuation value had diagnostic performances comparable to those of morphometric parameters, correlated better with functional obstructive indexes, and could be a marker of remodelling in asthma. In asthmatic mice, peribronchial attenuation values extracted from respiratory-gated micro-CT images correlate with remodeling. Therefore, the concept of bronchial wall attenuation seems to be promising for assessing non-invasively airways remodeling. Further studies are required to ensure the full reproducibility of these methods
Nouvelle stratégie antivirale contre le virus de l'hépatite C : détournement du complexe de réplication par des ARN non-codants by Gaëlle Chognard( Book )

2 editions published in 2010 in French and held by 3 WorldCat member libraries worldwide

The current treatment used against Hepatitis C Virus has a limited efficacy and is often hampered by the induction of side-effects. The specific delivery of antiviral proteins in infected cells should increase their efficiency and reduce their impact on healthy cells.Here, we describe the development of a new approach which takes advantage of the viral replication machinery to specifically target the antiviral protein expression to the infected cells. The strategy is based on the delivery of a non-coding replicative RNA (nrRNA) carrying the structures required for the binding of the viral replication complex, flanking the complementary sequence of an antiviral gene. The HCV replication complex replicates the nrRNA similarly to the viral genome to give a coding RNA from which the antiviral protein will be expressed. As non-infected cells do not express the replication complex, this specific machinery can be used to target virus-infected cells without affecting healthy cells.We show that this approach can be successfully applied in both replicon-harboring cells (genotype 1b) and JFH-1 infected cells (genotype 2a) : nrRNAs induced a strong decrease in genomic RNA and viral protein NS5A. These effects were correlated with a strong activation of several interferon stimulated genes.We also verify the harmlessness of the system in uninfected cells by transfecting a RicinA nrRNA. The replication and translation of this nrRNA lead to the cell death by ribosomes inactivation. But nothing occurs in non?infected cells, showing that nrRNA are neither replicated nor translated in absence of the HCV replication complex.The vectorisation of nrRNa was also developed by the use of modified lentivirale particles. We now test the efficient replication and translation of nRNAs in a murin model by using hydrodynamic transfection or the lentiviral delivery of nrRNAs
Etude des rétrotransposons LINE-1 dans la leucémie myéloïde chronique by Marina Josselin( Book )

2 editions published in 2012 in French and held by 3 WorldCat member libraries worldwide

Le gène hybride BCR-ABL1, responsable de la leucémie myéloïde chronique (LMC), code une protéine à activité tyrosine kinase constitutive. Lors d'une étude transcriptomique menée au laboratoire sur des patients résistants secondaires à l'imatinib, les deux gènes codant les protéines des rétrotransposons LINE-1 ont été trouvés sous exprimés d'environ 20 fois lorsque les patients rechutent. Le rôle des transposons n'a jamais été clairement défini, ils assurent certainement une fonction importante puisqu'ils sont conservés au cours de l'évolution et présents chez tous les organismes. Le but de ce travail a été d'étudier l'implication de LINE-1 dans la LMC. La sous-expression de LINE-1 est-elle une conséquence de la présence de BCR-ABL1 ou une cause de son apparition ? Différents groupes ont montré que les rétrotransposons LINE-1 possédent la capacité de réparation des cassures double-brin de l'ADN. Nous avons fait l'hypothèse qu'une diminution de l'expression des gènes codés par les rétrotransposons LINE-1 entraînerait l'instabilité génétique observée dans la LMC. Une étude réalisée chez des patients atteints de LMC et des sujets contrôles a montré une correlation inverse entre l'expression de LINE-1 et celle de l'oncogène BCR-ABL1. Parallèlement, une étude sur des lignées cellulaires leucémiques humaines BCR-ABL positives et négatives a été réalisée. Nous avons recherché le lien qui existe entre l'expression de LINE 1, de BCR-ABL1 et la réparation des cassures double-brin de l'ADN. Nous avons montré d'une part qu'une inhibition de l'expression de BCR-ABL1 induit une augmentation de l'expression des transposons LINE-1 D'autre part, une diminution de l'expression de LINE-1 entraîne une apparition du transcrit BCR-ABL1 dans les cellules BCR-ABL negatives
Impacts de l'oxygène sur les évolutions chimiques et sensorielles du vin rouge by Laurent Pechamat( Book )

2 editions published in 2014 in French and held by 2 WorldCat member libraries worldwide

The impact of oxygen has been followed-up during 4 months for 3 Merlot red wines of TPI 61, 63 anf 76. The wine of TPI 63 was supplied by a fraction of ellagitannin from oak wood. Wines have been adjusted at pH 3, pH 3.5 and pH 4. For each pH, quantities of 0, 2, 8 and 20 mg/L of pure oxygen have been added. Then, anlyses have been performed each month to follow the wine chemical and sensory evolutions in order to determine the impact of oxygen.For all wines, the results show that oxygen consumption is 2 to 4 fold higher from pH 3 to pH 4. The presence of ellagitannin in wine favors oxygen consumption, as well as in wine model solutions with phenolic fractions. Total tannin contents remain quite constant. Polymerisations analysed by DMACH index occur mainly at pH 3 and pH 3.5 for the wine of TPI 61, while the differences related to oxygen are less important in the wine of TPI 76. For the wine of TPI 63 + ellagitannins, polymerisations are favored at pH 3. Total and molecular anthocyanins contents generally show a decrease according to time, oxygen and acidity. For the wines of TPI 76 and TPI 63 + ellagitannins, the anthocyanins polymerise more to polymers of tannins with oxygen and acidity. 13 pyranoanthocyanins have been identified et quantified. Among them, two molecules of pyranomalvidin-di-(epi)catechin quantified for the first time in a dry red wine. They can be considerated as marker related to oxygen amount consumed by wine. Sensory analyses realized on wine of TPI 76 according to pH show that bitterness is higher at pH 4, and pH 3.5 in a lesser extent. There is the same trend with the oxidation perception.For the two other wines, of TPI 61 and 63 with ellagitannin fraction, fruity intensity globally decreases with oxygen quantities, while the oxidized parameter is well related to increasing oxygen amounts, as wella s bitterness in a lesser extent
Comportement de Scaphoideus titanus, conséquences spatiales et démographiques by Julien Chuche( Book )

2 editions published in 2010 in French and held by 2 WorldCat member libraries worldwide

The Flavescence dorée is an incurable phytoplasma disease of grapevine. This pathology is exclusively transmitted from plant to plant by the leafhopper vector Scaphoideus titanus. Despite the importance of this disease, few studies have been conducted on the vector. This thesis aims to provide knowledge on the biology and ecology of S. titanus but also more broadly on the ecology of phytophagous insects. Three major themes were addressed in this thesis: i) the relationships between the insect and its environment through the influence of winter temperatures on diapausing eggs, ii) the relationships of the insect with its host plant by examining the attractiveness of the plant and the feeding behaviour of the vector, iii) interactions between congeners in the study of the aggregative behaviour of larvae. Our results indicate that 1) cold temperatures are not essential to break the diapause but contribute to protandry through operational sex ratio regulation, 2) the attractiveness of the host plant is largely due to its colour and different instars exhibit differences in behavioural choices, 3) males and females have different feeding behaviour which may explain their different efficiencies at vection, 4) the aggregation of larvae did not seem to result from active recruitment and could contribute to horizontal insect to insect transfer of phytoplasma through the plant. Such knowledge can contribute to the development of alternative S. titanus pest management techniques
Modulation de la balance lymphocytaire T régulatrice et effectrice dans deux modèles de maladies auto-immunes by Clément Jacquemin( Book )

2 editions published in 2013 in French and held by 2 WorldCat member libraries worldwide

Respect of the balance between autoreactive T cells and regulatory T cells (LTreg) is important to maintain tolerance to self-antigens. Cellular partners and molecular mechanisms involved in the disruption of this balance are not or little known in autoimmune diseases.Thus, the work described in this thesis focuses on the disruption of the T effector/ Treg balance in two models of human autoimmune diseases: systemic lupus erythematosus and autoimmune hemolytic anemia (AIHA). We show an increased expression of the OX40L (CD252, TNFSF4) costimulatory molecule at the surface of both circulating and tissues-infiltrating antigen presenting cells in SLE patients. OX40L expression is correlated with disease activity in adults and in children and results in Tfh (follicular helper T) effector cells induction and Treg suppressive functions inhibition, two key mechanisms in the pathogenesis of lupus. In the second project, we show an increase of the circulating T8reg proportion in patients with a warm AIHA in a non-active state. These Treg express CD25, FoxP3 and exert their suppressive function by a mechanism involving IL-10. Low-dose IL-2 allows the expansion of this cell population in vitro. These results provide new insights into the pathophysiology of these diseases and offer potential therapeutic perspectives
Influencing factors on aromatic typicality of wines from Vitis vinifera L. cv. Riesling - sensory, chemical and viticultural insights by Armin Schuttler( Book )

2 editions published in 2012 in English and held by 2 WorldCat member libraries worldwide

The sensory concept of typicality of dry Riesling wines was demonstrated using different sensory analysis methodologies. This was achieved by comparison to other styles of dry white wines especially from Bordeaux, which showed strong Sauvignon blanc character. 'Fruity' descriptors like 'citrus fruit' and 'yellow fruit' were shown to be related to dry Riesling wines' typicality independently by two panels of wine experts. Analysis of volatiles by means of gas chromatography coupled to mass selective detection (GC-MSD) was realised in order to link sensory data to aroma compounds' concentrations. For the first time, concentrations of the high potent aroma compound 3 sulfanylhexan-1-ol (3SH) were shown to correlate with typicality ratings for Riesling wines. The impact of viticultural conditions during the grape vine growing period on finished wines' aroma was studied with respect to grape vine water status and leaf removal practices including precursor studies in berries and must. It was clearly shown that changing viticultural conditions influenced volatile aroma compounds' concentrations in finished wines, especially for 3SH, linalool and 1,1,6 trimethyl-1,2-dihydronaphthalene (TDN). Additionally the well-known aroma compound trans-ethyl cinnamate was identified to be a possible impacting aroma compound implicated in Riesling wines' aromatic typicality. The applied methodology using two-dimensional gas chromatography with olfactometric and high resolution mass spectrometric detection (2D-GC-O/HRMS) after a sensory guided fractionation using high pressure liquid chromatography (HPLC) in a comparative approach to dry white wines from Bordeaux, showed to be a powerful tool to decrypt Riesling wines' aroma. The totality of results allowed improving the knowledge on aromatic typicality of Riesling wines and the imparted aroma compounds and how those concentrations could be influenced by changing viticultural conditions
Approches sensorielle et analytique de l'arôme fruité des vins rouges : infuence relative des levures et des bactéries lactiques by Marine Gammacurta( Book )

2 editions published between 2014 and 2015 in French and held by 2 WorldCat member libraries worldwide

Les fermentations alcoolique (FA) et malolactique (FML) sont deux étapes importantes de la vinification en rouge dans l'établissement de l'arôme fruité des vins. Afin d'étudier l'importance relative des microorganismes fermentaires, nous étudions l'influence de six couples levures/bactéries lactiques (BL) - trois souches de levures, deux de BL - sur la modulation des notes fruitées de différents vins rouges de Bordeaux. Une première approche analytique montre l'influence prédominante de la souche de levures sur la concentration de plus de 70 marqueurs potentiels de la note fruitée. L'étude particulière des esters montre que l'effet levures observé dès la fin de la FA persiste au cours du temps malgré la FML et les modifications engendrées par le vieillissement du vin. L'étude sensorielle conforte l'influence majeure des levures sur la modulation de l'arôme fruité des vins rouges à différents temps d'élevage. Néanmoins, les résultats obtenus suggèrent l'implication d'autres composés aromatiques dans la modulation de la note fruitée des vins, non quantifiés dans la première partie de cette étude. Un travail de fractionnement d'extraits de vin par HPLC permet par la suite l'identification d'une fraction d'intérêt impliquée dans des variations aromatiques liées à la souche de levures. L'analyse de cette fraction par chromatographie en phase gazeuse n'a pas permis d'identifier le ou les composés impliqués. Nous avons néanmoins mis en évidence une thiophénone qui pourrait agir en tant que masque de l'arôme fruité, ainsi qu'un ester hydroxylé qui pourrait s'avérer être un marqueur intéressant de l'activité bactérienne et dont l'effet exhausteur de notes fruitées est également envisagé comme perspectives
Etude de l'impact de l'Esca sur la qualité des raisins par une approche protéomique by Grégory Pasquier( Book )

2 editions published in 2012 in French and held by 2 WorldCat member libraries worldwide

The vine is susceptible to many fungal diseases that will affect the quality of grapes and wines. For several years, Esca has become the bane of modern viticulture because it is responsible for the death of the vines when presented in the form apoplectic. Its chronic form is associated with the presence of a procession of pathogenic fungi in the trunk and arms that will most often cause leaf symptoms. The alteration of photosynthesis that this causes will affect fruit ripening. However, little research has been conducted to characterize precisely the impact of this disease on the metabolism and chemical composition of grape berries. Our study aimed to assess, using a proteomic approach the disease's impact on the quality of grapes and get specific markers. Our work allowed us to demonstrate that the expression of foliar symptoms of Esca causes a change in abundance of proteins related to defense mechanisms and oxidative stress in the grape skin. It is also observed a change in antioxidant capacity by modulating levels of hydrogen peroxide, glutathione or pyridoxine. The concentrations of molecules of oenological interest such as amino acids, biogenic amines or tannins are also modified in the presence of foliar symptoms of Esca
Localisation et caractérisation des tannins dans la pellicule du raisin : impact de l'organisation physico-chimique des parois cellulaires sur la composante tannique, la qualité du fruit et la typicité des raisins de Bordeaux by Soizic Lacampagne( Book )

2 editions published in 2010 in French and held by 2 WorldCat member libraries worldwide

Skin grape maturation is a complex phenomenon, characterized by an important number of structural changes as well as by phenolic compounds accumulation (i.e. tannins). Despite their biological and organoleptic properties in fruit and wine quality, few studies report both tannins organization and localization in skin tissue. In skins, tannins may be more or less related with cellular components, modulating their extractability during winemaking process.Our work, based on biochemical, molecular and microscopic approaches reveals new data on skin tannins biosynthesis, localization and organization. Within this tissue, we highlighted the parietal tannins importance, we evidenced that their physicochemical characteristics depend among other structural changes on cell walls. Thus, this organization partially characterized the skin texture and affects fruit quality. To understand the evolution criteria for skin texture during grape berry ripening, sensory analysis and measurements by penetrometer proved to be relevant tools
Cytogénétique placentaire des retards de croissance intra-utérins : intérêts de la recherche des anomalies chromosomiques limitées au placenta et de l'estimation de la longueur télomérique placentaire by Jérôme Toutain( Book )

2 editions published in 2012 in French and held by 2 WorldCat member libraries worldwide

This thesis proposes to study intrauterine growth restriction in terms of cytogenetics of placenta, with two distinct and complementary approaches. The first approach will be to reassess the influence of confined placental mosaicism on fetal growth, as previous studies have reported conflicting results on this issue. The first part of this work will also study the influence of fetal uniparental disomy in case of confined placental mosaicism. The second approach of our work will focus on the length of terminal chromosomal structures, telomeres, at the placental level. It has recently been reported that telomere length was reduced in placental cells collected at term in pregnancies complicated by intrauterine growth restriction. Placental telomere length has never been evaluated in ongoing pregnancies and it could potentially be used as a placental biomarker of intrauterine growth restriction. The second part of this work will also focus on the copy number of chromosomal regions carrying genes encoding the main subunits of the telomerase enzyme complex and will look for the presence of placental telomeric aggregates in case of intrauterine growth restriction
Importance des interactions perceptives dans l'expression de l'arôme fruité typique des vins rouges by Georgia Lytra( Book )

2 editions published in 2012 in French and held by 2 WorldCat member libraries worldwide

Most of volatiles involved in red wines' fruity expression are present at levels below or close to their individual perception thresholds. Given the existence of perceptive interactions between them, it is very difficult to determine their real impact on wine aroma. Rather than assessing the olfactive behavior of mixtures prepared from pure products, the main goal of this work was to highlight and study the impact of perceptive interactions on wine fruity aroma expression using various aromatic reconstitutions prepared from wine fractions. Sensory profile analyses identified significant differences among aromatic reconstitutions for the intensity of some descriptors, as particular "additive" or "masking" effects. The composition of the involved fractions was then studied by instrumental methods. The final target was to investigate the impact of fraction components on fruity aroma by preparing aromatic reconstitutions and using sensory reconstitution tests, to assess the role of these compounds on the perceptive interactions previously observed. Further analysis revealed that ethyl 2-hydroxy-4-methylpentanoate, eluted in fraction which had an "additive" effect on the black-berry and fresh fruity aroma, does not play a direct role as a key compound in red wine aroma. In contrast, our findings highlighted its indirect contribution to wine aroma, showing that this ester contributed to a synergistic effect, enhancing the perception of fruity character. Finally, it was clearly demonstrated that this compound acts as a natural enhancer for black-berry and fresh fruit notes in red wine. It was also established that diacetyl, acetoin, acetic acid and [gamma]-butyrolactone together played the same hypo-additive role as fractions of which they were eluted, presenting a "masking" effect on fresh fruity aroma. The impact of the last three compounds was demonstrated conclusively, even at subthreshold concentrations. These findings highlighted the existence of new remarkable perceptual interactions impacting overall and fresh-fruit aroma perception. The particular behavior, in a fruity mixture, of ethyl-propanoate, ethyl-3-hydroxybutanoate, butyl acetate and 2-methylpropyl acetate, present at subthreshold concentrations, was demonstrated. The presence of ethyl-3-hydroxybutanoate and 2-methylpropyl acetate in mixture led to a significant decrease of the olfactory threshold of fruity pool confirming their synergistic effect in the overall increase intensity. These compounds with close chemical structures, participate, both quantitatively and qualitatively, in the modulation of red wines' fruity aromas acting as natural enhancers of black-berry and fresh-fruit aromas
Interactions entre levures Saccharomyces cerevisiae et non-Saccharomyces en vinification. : Incidence de facteurs de l'environnement. by Laura Chasseriaud( Book )

2 editions published in 2015 in French and held by 2 WorldCat member libraries worldwide

Non-Saccharomyces yeasts, naturally found in grape must, can impact wine quality positively or negatively. In recent years, the use of mixed cultures as starters (association of S. cerevisiae species and other species) such as the couple Saccharomyces cerevisiae/Torulaspora delbrueckii is proposed to winemakers. Interactions between these two species have been studied with two commercial strains, T. delbrueckii Zymaflore Alpha and S. cerevisiae Zymaflore X5 (Laffort). Alcoholic fermentations were carried out in a fermentor with double compartment allowing a physical separation of yeasts and preserving the homogeneity culture medium. The results highlighted that the physical separation impacts the growth of both strains, suggesting interactions of type cell-cell contact between these two strains. If a large majority of winemakers use selected yeasts strains, some of them chose to favor native yeasts, S. cerevisiae species and non- Saccharomyces species. The impact of two environmental factors was investigated on five non-Saccharomyces species (T. delbrueckii, Metschnikowia spp., Candida zemplinina, Hanseniaspora uvarum, Pichia kluyveri) and two strains of S. cerevisiae (one with short fermentation lag phase, one with long fermentation lag phase), in pure and mixed cultures. The inoculation with S. cerevisiae with a long fermentation lag phase in a must saturated with CO2 allowed to stimulate some of non-Saccharomyces which present an interest in winemaking (T. delbrueckii/P. kluyveri) and inhibit the undesirable ones (H. uvarum, C. zemplinina)
Incidence de l'oxydation des composés phénoliques sur la composante aromatique des vins blancs by Maria Nikolantonaki( Book )

2 editions published in 2010 in French and held by 2 WorldCat member libraries worldwide

Les réactions d'oxydation impliquant les composés phénoliques semblent induire des modifications non négligeables du profil chimique et sensoriel des vins. Les travaux concernent l'étude des mécanismes réactionnels impliquant certains thiols volatils, contributeurs de l'arôme distinctif et de la complexité des vins des différents cépages avec les composés phénoliques oxydés des vins blancs, principalement les flavan-3-ols. En solution modèle de composition proche du vin, une réactivité différente des thiols volatils selon leur nature chimique vis à vis des formes oxydées des flavan-3-ols a été établie. La synthèse et la caractérisation des adduits par RMN entre les principaux composés phénoliques des moûts et des vins blancs et le 3-sulfanylhexanol, présentant des nuances d'agrumes, a ensuite été réalisée en conditions d'oxydation chimique et enzymatique. La suivi cinétique de la formation des adduits par CLHP-ESI-SM a permis de mettre en évidence une réactivité du thiol spécifique vis à vis d'un substrat polyphénolique, d'établir le rôle catalytique des métaux (Fe2+) et la capacité antioxydante du dioxyde de soufre vis à vis de ces mécanismes réactionnels. La compréhension de mécanismes fondamentaux de la réactivité de la (+)-catéchine et de la (-)-épicatéchine en conditions œnologiques avec les thiols volatils nous a permis de décliner les travaux à l'étude de l'influence de la présence des flavan-3-ols au cours de la vinification et de l'élevage des vins sur ces composants de l'arôme des vins blancs
Marqueurs comportementaux et corrélats neurobiologiques de la prise de décision adaptée et inadaptée chez le rat by Aurélie Fitoussi( Book )

2 editions published in 2011 in French and held by 2 WorldCat member libraries worldwide

Une prise de décision inadaptée est au centre de nombreuses pathologies neuropsychiatriques, telle que la toxicomanie, mais concerne également certains sujets sains, pour lesquels les gratifications immédiates prévalent sur les conséquences à long terme. Afin de mieux comprendre les bases neuropsychologiques et neurobiologiques de la prise de décision dans un cadre normal et pathologique, les sujets sains inadaptés constituent un modèle prometteur. Une tâche de mesure de la prise de décision chez le rat (le Rat Gambling Task, RGT) a récemment été validée dans l'équipe, très similaire à l'Iowa Gambling Task chez l'homme et permettant de révéler, parmi une population saine de rats, une majorité de sujets performants, et une minorité de non performants. Ces rats persistent à choisir les options immédiates les plus récompensantes, mais associées à de fortes pénalités imprédictibles, entrainant un faible gain final. Nous avons montré que tous ces rats sont inflexibles et moins efficaces dans la qualité du caractère dirigé de l'action. Ils présentent également une motivation accrue pour les récompenses, qui dépend d'une balance complexe coût/bénéfice, étroitement liée à l'effort à fournir, à la palatabilité de la récompense mais pas à la perception de la sensation plaisante ou des besoins métaboliques. Par ailleurs, nous avons montré qu'il n'existe pas de relation directe entre les capacités de mémoire de travail et la prise de décision. Sur le plan neurobiologique, nous avons montré 1) que la qualité du caractère dirigé de l'action dépend d'une balance d'activité PL/SDM et 2) que la prise de décision dans le RGT engage différemment des structures spécifiques selon les performances dans la tâche et la cinétique d'élaboration des choix. Ainsi, le fort recrutement de l'OFC et du Nacc shell serait un marqueur de choix adaptés, alors que celui de PL/SDM serait modulé selon la rapidité à préférer les choix favorables. Le CgA, IL et l'amygdale se désengageraient lorsque les choix sont établis. Les rats non performants présentent une hypoactivité préfrontale associée à une activité persistante de l'amygdale, suggérant un contrôle cognitif préfrontal déficient, couplé à une altération dans les associations liées à la valeur des options, induisant un déficit d'acquisition et de ré-actualisation de la valeur incitative des choix. Nous avons également montré que les différences inter-individuelles dans le RGT sont associées à des différences dans le fonctionnement basal du système monoaminergique. Les rats non performants présentent notamment (1) des métabolismes DA- et 5HT-ergique plus élevés au niveau d'IL, en accord avec l'impulsivité motrice de ces rats, et/ou la moindre qualité du caractère dirigé de l'action et (2) un métabolisme DA-ergique plus élevé au niveau du Nacc core et 5HT-ergique plus faible au niveau du BLA, suggérant une relation étroite avec leur motivation accrue et la qualité des associations liées à la valeur des options. Finalement, ces données sont intéressantes au regard des modifications dans le fonctionnement monoaminergique de base induites par des polymorphismes génétiques, conduisant à une prise de décision inadaptée, ainsi qu'à certaines pathologies psychiatriques. Toutes ces caractéristiques comportementales et neurobiologiques qui forment un ensemble cohérent pourraient correspondre à un endophénotype de troubles mentaux. Les études à l'avenir devront investir la relation directe avec la pathologie, telle que l'addiction, et l'exploration de ces caractéristiques au niveau génétique
Caractérisation phénotypique de l'espèce Torulaspora delbrueckii en conditions œnologiques. Application à la co-inoculation avec l'espèce Saccharomyces cerevisiae by Philippe-Emmanuel Renault( Book )

2 editions published in 2010 in French and held by 2 WorldCat member libraries worldwide

La caractérisation phénotypique de l'espèce Torulaspora delbrueckii en conditions œnologiques, à partir de l'étude d'un grand nombre de souches, a permis de mettre en évidence une grande variabilité au sein de cette espèce. En effet, les souches de T.delbrueckii présentent des différences au niveau des durées de phase de latence et de fermentation, des capacités biotiques mais aussi des productions d'éthanol (maximum 12% vol.). Cette variabilité se retrouve également pour la production d'acidité volatile, de glycérol et de certains arômes. Ce travail confirme les faibles productions d'acidité volatile et de glycérol de cette espèce et met en évidence une réponse au stress osmotique différente de celle de l'espèce Saccharomyces cerevisiae. Au final, l'espèce T. delbrueckii présente une grande « pureté » de fermentation et produit peu de composés indésirables comme le sulfure d'hydrogène, les phénols volatils, l'acetoïne, l'acétaldéhyde et le diacétyle. La réalisation de co-inoculations T. delbrueckii / S. cerevisiae sur moûts liquoreux, permet une réduction systématique de l'acidité volatile des vins, en comparaison à une fermentation pure de l'espèce S. cerevisiae, quelque soit la souche de T. delbrueckii utilisée. De plus, la souche T. delbrueckii OXT1 1//2 a permis de complexifier la composition aromatique d'un moût sec issu du cépage Sauvignon blanc (esters fermentaires +25%, phényl-2-éthanol +51% et thiols volatils +31%). Enfin, la mise au point d'un fermenteur à double compartiment, avec une séparation physique des levures tout en conservant l'homogénéité du milieu de culture, a permis d'aborder l'étude des interactions entre ces 2 espèces. Des inhibitions de type « cell-cell contact » ont ainsi été mises en évidence
Communautés microbiennes de la baie de raisin : Incidence des facteurs biotiques et abiotiques by Guilherme Marques Martins( Book )

2 editions published in 2012 in French and held by 2 WorldCat member libraries worldwide

The study of microbial communities associated with wine grapes under field conditions revealed changes in the size and structure during the berry ripening process, with levels rising gradually and reaching their highest value when the berries were over ripe. During this work several bacteria and fungi species, including fermentative yeast, have been isolated and identified. From cultured bacteria, over 44 species were identified from 21 genera. Concerning fungi population, among eight genera identified, the genus Aureobasidium was the most abundant. Our study reveals the impact of different abiotic and biotic factors over microbial community structure, density and metabolic activity. Comparing different vineyards in the same region, we observed that areas presenting more humid and colder climate favor the growth of microorganisms. Our results also show that the farming system has a clear impact on the microbial community, especially in the bacterial fraction. One of the reasons is the inhibiting effect of copper-based fungicides, frequently used in both organic and conventional farming systems. The presence of Botrytis cinerea in grape berries without visual symptoms of infection can change the microbial community of the grapes, increasing bacterial population density and diversity
Évaluation de ligands pour l'imagerie moléculaire de la néoangiogenèse tumorale by Frédéric Debordeaux( )

1 edition published in 2015 in French and held by 1 WorldCat member library worldwide

Tumor neoangiogenesis is a predictive element of the evolution of numerous cancers. AlphaVbeta3 integrin and matrix metalloprotease 9 (MMP-9) are markers of tumor neoangiogenesis. Their targeting appears of great interest either for early detection, aggressiveness staging of the disease or for selection of responders to new-targeted therapies. In this context, our objective is to develop methodologies needed for radiotracers characterization. Tracers have been investigated in different tumor models for which vascularization is very important: melanoma and glioma. First of all 99mTc-DTPA-bis-c(RGDfK) has been assessed in our laboratory and helped us to develop analytical methods. These methodologies were used in different partnership, the evaluation of 18F-ribofuranose-RGD targeting alphaVbeta3 with INSERM UMR 1037 and CNRS UMR 5255, and 111In-DOTA-F3B for molecular imaging of MMP-9 with INSERM UMR 869 and CNRS UMR 5306.The technetium peptide has demonstrated good affinity and specificity for alphaVbeta3. In vivo analysis in mice showed that both tracers were able to identify some alphaVbeta3-positive tumors. 111In-DOTA-F3B allowed us to detect hMMP-9 positive tumors in mice and in tumor tissue sections. In conclusion, these tracers still require to be investigated but represent promising tracers for tumor neoangiogenesis
The role of intrinsic neuronal excitability for Prelimbic network function by Rafael De Sa( )

1 edition published in 2019 in English and held by 1 WorldCat member library worldwide

The goal of this work was a characterization of the cellular identity of Layer 5 neurons of the prelimbic (PL) subarea of the medial prefrontal cortex (mPFC) in mice. In performing this analysis, we considered the intrinsic properties of these neurons, their morphology, connectivity and finally their transcriptional profile. In the first part of this study, we considered the question of how the expression of the receptors a of important neuromodulatory molecule (dopamine) can be used, in addition to other criteria, for the characterization of cell-type identity. In the PL, two major receptor types, Dopamine 1 (D1R) and 2 (D2R) receptor have been described. We characterized the cellular identity of these neurons in wild-type (WT) mice and then used these findings as a reference for the characterization of molecular and cellular defects in the PL of Fmr1KO, a model for fragile X syndrome (FXS) and autism spectrum disorder (ASD). To do this, we analyzed the intrinsic electrical properties of these neurons and performed a clustering of neurons based on these intrinsic properties. We analyzed the morphology of these neurons, as well as their principal projections to other brain areas. In addition, RNA sequencing analysis revealed more than 500 genes differently expressed between D1R and D2R neurons. Further analysis of the transcriptional profile of these neurons revealed differences based on a number of different categories such as the expression of ion channels, transcription factors and cell adhesion molecules. This data then served as a reference for the characterization of molecular and physiological changes in the PL in FXS/ASD. FXS is the most common inherited cause of intellectual disability and the most frequent genetic cause of autism. FXS is characterized by learning and memory deficits, repetitive behavior, seizures and hypersensitivity to sensory (e.g. visual) stimuli. Dopamine modulation is altered in this model and it was thus pertinent to determine how changes to this important modulatory system might impact on cell identity in FXS. We observed differences in intrinsic properties between D1R and D2R neurons. However, these changes showed important differences from those observed in WT mice. These differences might be explained by alterations in mRNA expression in these two neuronal populations in Fmr1KO mice. In particular, our findings point to an overexpression of genes particularly in D1R population of Fmr1KO mice. In the second part of this study, we turned our attention to changes in the intrinsic electrophysiological properties of amygdala-projecting PL during early encoding of contextual fear memories. We used contextual fear conditioning together with retrograde tracing and whole-cell electrophysiological recordings of labeled pyramidal neurons in adult 2-3 month old male C56BL/6J mice. We show that neurons projecting to the amygdala display learning-dependent changes in neuronal excitability during early encoding of contextual fear conditioning, but not at a remote time-point. In addition, we demonstrated that manipulation of the intrinsic properties of this specific population during the early phases or memory encoding (but not during remote phases) lead to alterations in fear memory recall at a remote time-point
 
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Alternative Names
École doctorale 154

École doctorale des sciences de la vie et de la santé (Bordeaux)

École doctorale des sciences de la vie et de la santé (Talence, Gironde)

École doctorale SVS (Bordeaux)

ED 154

ED Sciences de la vie et de la santé (Bordeaux)

ED SVS. Bordeaux

ED154

EDSVS (Bordeaux)

Sciences de la vie et de la santé (Bordeaux)

Sciences de la vie et de la santé (Talence, Gironde)

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French (35)

English (3)