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École doctorale SIReNa - Science et ingénierie des ressources naturelles (Lorraine)

Overview
Works: 97 works in 97 publications in 2 languages and 97 library holdings
Roles: Other
Publication Timeline
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Most widely held works by École doctorale SIReNa - Science et ingénierie des ressources naturelles (Lorraine)
Implication des récepteurs de la dopamine dans la régulation de l'axe gonadotrope lors de la période pré-ovulatoire chez le sandre, Sander lucioperca by Jennifer Roche( )

1 edition published in 2018 in French and held by 1 WorldCat member library worldwide

Prédiction de propriétés agroécologiques de prairies permanentes et de leurs compromis : l'exemple du massif vosgien by Geoffrey Mesbahi( )

1 edition published in 2020 in French and held by 1 WorldCat member library worldwide

Les prairies permanentes ont un intérêt majeur en France : elles assurent la moitié de la production fourragère, accueillent une riche biodiversité, et séquestrent le carbone. Mieux comprendre les déterminants des propriétés agroécologiques, mais aussi leurs compromis, peut aider les agriculteurs, leurs conseillers agricoles et les écologues à valoriser des prairies diversifiées, et une diversité de prairies. Les objectifs de cette thèse sont 1) d'identifier les critères du milieu, des pratiques agricoles et de la végétation qui prédisent les propriétés prairiales, 2) de prédire les propriétés agroécologiques à l'aide de typologies de prairies, sans connaissance précise des critères environnementaux ni des pratiques agricoles, 3) d'étudier et prédire les compromis entre propriétés d'une même prairie, 4) de se questionner sur la transmission des connaissances entre scientifiques, agriculteurs et conseillers. Pour atteindre ces objectifs, j'ai valorisé une base de données de près de 800 prairies permanentes d'études précédentes. J'en ai extrait 59 prairies représentatives du massif vosgien, sur lesquelles j'ai réalisé des relevés botaniques, des mesures de rendement, et des prélèvements de fourrage et de sol, et collecté des informations sur les pratiques agricoles, le climat et la topographie. Les résultats montrent que les compositions botaniques sont difficilement prédictibles et principalement influencées par des gradients d'intensité des pratiques, de sol et d'altitude. La prédiction des propriétés agroécologiques montre de grandes variabilités de qualité : des propriétés écologiques et agronomiques sont correctement prédites par des critères du sol, du climat, du paysage et de la composition botanique. Les propriétés écologiques sont difficilement prédictibles avec les typologies prairiales seules, mais la combinaison de typologies améliore la qualité des prédictions. Les résultats montrent aussi qu'une même prairie ne peut pas répondre à toutes les attentes des agriculteurs et conseillers, mais il est possible d'associer rendement et diversité botanique ; qualités nutritives ; ou encore espèces patrimoniales et souplesse d'exploitation. Enfin, la réflexion sur la transmission des connaissances entre scientifiques et acteurs de terrain montre qu'il est nécessaire de trouver un équilibre entre précision des outils et facilité d'utilisation afin de s'adapter aux attentes de tous. Cette thèse apporte donc de nouvelles connaissances sur la prédiction des propriétés agroécologiques des prairies permanentes et de leurs compromis à grande échelle, notamment grâce à la prise en compte de nombreux critères prédictifs liés aux milieux, aux pratiques agricoles et à la végétation, mais aussi grâce à la prédiction de propriétés encore méconnues. Enfin, cette thèse soulève le problème de la création d'outils polyvalents permettant de prédire les propriétés agroécologiques des prairies permanentes
Nanofunctionalization and biofabrication of natural hydrogels for tissue engineering applications by Kamil Elkhoury( )

1 edition published in 2021 in English and held by 1 WorldCat member library worldwide

The main objective of this thesis is to develop a new natural material based on methacrylated gelatin (GelMA) nanofunctionalized by the incorporation of nanoliposomes or soft hybrid exosome-liposome nanoparticles. The physicochemical and biological properties of these hydrogel matrices were characterized in order to evaluate their potential use for tissue engineering applications. GelMA is prepared by the chemical modification of gelatin when methacrylate groups are attached to side groups containing amine functions. In a first part of this work, the influence of the gelatin source (pork or fish) and the degree of methacrylation on the physicochemical and biological properties of hydrogels was studied. In a second part of this work, the GelMA matrix was nanofunctionalized by the incorporation of nanoliposomes, which are soft and natural nanoparticles with remarkable self-assembly properties. These well-established drug delivery systems‎ are formed of lipid bilayers and can transport and release hydrophobic, hydrophilic, and amphiphilic molecules. In this study, naringin, an active molecule that can guide the differentiation process of stem cells to the osteoblastic lineage, was encapsulated in nanoliposomes before their incorporation into the GelMA polymeric matrix in order to develop a system of interest for bone regeneration applications. This nanocomposite material was physicochemically and biologically characterized and the release profile of naringin was investigated. In a third and final part of this work, the GelMA matrix was nanofunctionalized by the incorporation of exosome-liposome soft hybrid nanoparticles. Exosomes, natural nanovesicles secreted by cells, are of increasing interest for targeted drug delivery applications due to the presence of cell specific receptors on their surface. The hybrid GelMA hydrogels were physicochemically and biologically characterized for applications in cardiac reprogramming and was successfully bioprinted and microfabricated. Biofabricated GelMA hydrogels nanofunctionalized with nanoliposomes or hybrid exosome-liposome nanoparticles are promising platforms for the controlled release of bioactive molecules and for tissue engineering applications
Évolution de l'Himalaya de la fin du Miocène à nos jours à partir de l'histoire de son érosion by Sébastien Lénard( )

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

La communauté des sciences de la Terre est animée d'un intense débat sur l'impact des Glaciations sur les chaînes de montagnes. Les montagnes forment leur relief à partir des interactions entre la tectonique, le climat et l'érosion. L'érosion détruit les roches en altitude et les rivières et les écoulements gravitaires sous-marins (turbidites) en transfèrent les débris vers les bassins sédimentaires. L'érosion résulte de l'action des précipitations, des rivières ou des glaciers. Des études suggèrent que les changements dans l'amplitude ou la saisonnalité des précipitations et les changements dans l'étendue des glaciers ont provoqué une augmentation mondiale et considérable des taux d'érosion sur les derniers millions d'années. Cependant, cette hypothèse est débattue car les taux d'érosion passés sont estimés avec des approches indirectes. Ici, je me concentre sur l'Himalaya, la chaîne de montagne par excellence située à la convergence des plaques indiennes et eurasiennes. C'est là que se développent les plus hauts sommets et les vallées les plus profondes de la Terre. Les glissements de terrain et l'érosion glaciaire fournissent l'un des flux sédimentaires les plus élevés aux océans. Pour déterminer les taux d'érosion passés, j'ai mesuré la quantité d'isotope cosmogénique 10Be accumulée dans le sédiment de quartz. Ces isotopes sont produits à la surface de la Terre par l'interaction des rayons cosmiques avec la matière. Les isotopes s'accumulent progressivement dans les roches proches de la surface, en fonction de l'altitude et des taux d'érosion. La concentration isotopique du sédiment donne accès au taux d'érosion moyen du bassin versant à la source de celui-ci. Pour déterminer la source des sédiments et le paléoenvironnement de dépôt, j'ai effectué des mesures complémentaires sur les isotopes Sr-Nd et C-O. J'ai réalisé mes mesures sur deux sites. Le site A est constitué de turbidites sableuses sédimentées dans les fonds marins de la baie du Bengale et recueillies par les expéditions 353 et 354 du programme scientifique IODP. Le site B est constitué de molasses déposées au front de l'Himalaya, dans les collines des Siwaliks, au sein du sanctuaire animalier de Valmiki en Inde. Le site A intègre l'érosion des bassins versants du Gange et du Brahmapoutre, couvrant l'Himalaya central et oriental. Le site B intègre l'érosion du bassin Narayani-Gandak, qui couvre le centre du Népal. Mes résultats donnent un aperçu sans précédent de la variation de l'érosion dans une chaîne de montagnes au cours des sept derniers millions d'années. Ils impliquent que les taux d'érosion moyens sont stables depuis au moins trois millions d'années dans l'Himalaya, malgré les variations dans le transfert sédimentaire ou sur le lieu de l'érosion, et malgré les glaciations intenses de la fin du Cénozoïque
Transport of polymer solutions in controlled low permeability porous media of various mineralogies by Imane Guetni( )

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

La récupération assistée du pétrole est considérée comme une option intéressante pour les réservoirs à faible perméabilité. Cependant, son application peut s'avérer difficile pour des perméabilités inférieures à 100mD, en raison des problèmes d'injectivité et de rétention élevée des additifs chimiques fréquemment observés dans ces cas. Ce travail de thèse vise à étudier l'impact des paramètres physico-chimiques et minéralogiques sur le transport des solutions de polymère dans des milieux poreux modèles de faibles perméabilités. Pour cela, des expériences d'injection de polymère ont été menées en utilisant des solutions d'HPAM de différentes forces ioniques et duretés et quatre milieux granulaires à base de quartz et trois types d'argiles: kaolinite, illite et smectite. Les résultats confirment le rôle majeur joué par la composition de l'eau d'injection (salinité et dureté) sur la conformation des polymères et sur les interactions polymères-minéraux. De fortes interactions entre le polymère et l'argile sont mises en évidence avec des différences significatives selon le type d'argile : bonne propagation et rétention élevée du polymère dans une argile non chargée et non gonflante (kaolinite) et faible propagation avec une rétention plus faible que prévu dans les argiles chargées ou gonflantes (illite, smectite). Ces résultats constituent de nouveaux éléments pour la compréhension du transport des solutions de polymères dans les réservoirs de grès à faible perméabilité
Effets de nanomatériaux chez deux espèces de bivalves le long d'un gradient de salinité : approches intégrées physiologiques et moléculaires by Vanessa Koehle-Divo( )

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

Nanotechnology is constantly evolving and leads to the incorporation of engineered nanomaterials (ENM) into daily commercial products. The synthesis of ENM and the use of products containing those ENM leads to their release in the environment but the risk of ENM is not yet known. The particular physico-chemical properties of ENM makes the evaluation of their toxicity particularly difficult and still not completely solved now. This thesis is integrated to the ANR NanoSALT (2013-2017) and aims to evaluate the fate and the effects of cerium dioxide and copper oxide ENM in two bivalve species representative of freshwaters (Corbicula fluminea) and of seawaters (Scrobicularia plana). The organisms were exposed to realistic concentrations of these ENM at different stage of their life-cycle, and through the setting up of exposure increasingly closed to environmental conditions (micro- and mesocosms). Nowadays, few nanotoxicology studies have adopted an approach of molecular biology for the evaluation and the comprehension of ENM effects in invertebrates, and more particularly in non-sequenced species. One of the objective of the thesis was to use the qPCR approach for the evaluation of the gene expression perturbation by ENM. This work allowed to determine the fate and the behavior of ENM in the different exposure conditions. The evaluation of ENM effects has been done at different biological scales (molecular, cellular, individual). The use of multivariate statistical tools has been particularly useful for the analysis of the expression variations of the targeted genes. The multi-marker approach at different biological scales allowed the integration of a lot of data, which generally allowed us to differentiate the effects of the different forms of ENM
Étude fonctionnelle de facteurs de maturation tardifs des protéines fer-soufre chloroplastiques chez A. thaliana by Mélanie Roland( )

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

De nombreux processus cellulaires tels que la respiration, la photosynthèse, l'assimilation du soufre et de l'azote ou encore la synthèse de vitamines ou de métabolites secondaires, dépendent de protéines à centre fer-soufre (Fe-S). Chez les plantes, la maturation de protéines Fe-S chloroplastiques, mitochondriales et cytosoliques ou nucléaires repose sur les machineries SUF, ISC et CIA respectivement. Dans le chloroplaste, un centre Fe-S, assemblé sur un complexe d'échafaudage SUFBC2D, est transféré via un ensemble de protéines de transfert vers les protéines cibles. L'objectif était de comprendre le rôle des protéines de transfert SUFA1, IBA57.2 et NFU1 en analysant leur capacité à lier des centres Fe-S et en isolant leurs partenaires au sein de la machinerie SUF et parmi les cibles chloroplastiques connues afin d'élucider les mécanismes moléculaires de ces interactions. Les expériences de reconstitution de centres Fe-S in vitro à partir des protéines recombinantes ont montré que SUFA1, NFU1 et le complexe SUFA1-IBA57.2 lient différents types de centres Fe-S. De plus, NFU1 incorpore un centre [4Fe-4S] au sein d'un dimère qui peut être transféré vers SUFA1, mais aussi vers les protéines cibles ISPG et THIC, deux enzymes impliquées dans la synthèse des isoprénoïdes et de la thiamine. L'ensemble des interactions identifiées par double hybride en levure et/ou BiFC pour ces protéines, mais aussi pour NFU2, NFU3 et HCF101, ont permis d'affiner leurs rôles respectifs dans la maturation des quelques 50 protéines Fe-S chloroplastiques
État sanitaire et croissance radiale des arbres : Analyse spatiale et temporelle des données du réseau systématique de suivi des dommages forestiers by Clara Tallieu( )

1 edition published in 2020 in French and held by 1 WorldCat member library worldwide

For the past 30 years, annual visual assessments of crown condition, on the French part of the transnational monitoring network (ICP Forests, level 1), was essential for monitoring forest health. However, the use of crown condition as an indicator of tree health is regularly questioned for methodological reasons but also because of the lack of knowledge on the determinism of crown condition and its functional impact on the tree. In this context, and through the records of 9 tree species' crown condition (deciduous and coniferous) spread over more than 300 plots in France, we have 1) described and interpreted the spatial and inter-annual variations of leaf loss, in addition to 2) discussing the use of crown condition as an indicator of tree health status based on the joint analysis of inter-annual variations of leaf loss and radial growth. The analysis of spatial variations in crown condition between plots showed multiple relationships with edaphic and climatic factors, but with relatively moderate explanatory power. The study of inter-annual variations in crown condition confirmed that the climatic factors of the previous year control crown condition of the current year. However, compared to radial growth, crown condition presents a less dynamic and inconsistent response to climate between trees in the same plot. The joint analysis of the two signals showed the existence of a weak link between growth and crown condition. We only observed a decrease in tree growth in the case of important leaf loss during years of extreme climatic hazards (dry or cold). However, the introduction of leaf loss as a predictor of radial growth had little or no significant effect for beech and fir. Finally, the evidence of the major influence of age on leaf loss precludes the interpretation of raw crown condition as an indicator of tree health
Étude des facteurs biotiques et abiotiques influant sur la structuration et la composition du microbiote racinaire du Peuplier by Lauralie Mangeot-Peter( )

1 edition published in 2020 in French and held by 1 WorldCat member library worldwide

Microorganisms play an essential role in the functioning of forest ecosystems. The pool of the root- associated microorganisms is called “root microbiome” and is known to promote tree growth, improve tree resistance to biotic and abiotic stresses and participate in nutrient cycling. Studying the factors that structure and regulate the root microbiome is essential to better understand the mechanisms involved in tree-microorganism interactions and the role of the tree root microbiome in response to current and future environmental constraints. During my thesis, I studied the colonization dynamic of grey poplar roots by bacterial and fungal communities in the soil by combining metagenomic and microscopic approaches. In parallel, a mesocosm study was carried out to determine the impact of the host genotype and environmental factors such as climate and soil type on the root microbiome of black poplar, a species that colonizes riparian ecosystems and is particularly affected by climate change. Finally, through metagenomic and metabolomic approaches, I studied, on the one hand, the impact of soil microbiome variations and, on the other hand, the signalling pathway of jasmonic acid, a phytohormone involved in defence, on the metabolome and communities of the root microbiome of grey poplar. The results of my thesis highlight the significant impact of the tree and environmental factors on the composition and taxonomic and functional structure of the root microbiome as well as the need to consider the tree and its microbiota as a "meta-organism" in its own right
Caractérisation des bactéries du sol forestier isolées au niveau des microhabitats et de leurs interactions avec le peuplier by Milena Gonzalo( )

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

Soil borne microbes are vital contributors to forest ecosystems through soil services such as organic matter decomposition, nutrient cycling and sustaining plant growth. Bacteria and fungi form complex networks of interactions belowground interconnected with roots and assisting plants with water, nutrients, and some can help overcome pathogenic damages. During these biotic interactions, there is an exchange of signal molecules and metabolites that modify the local environment and can affect the presence and growth of surrounding microbial neighbours. These alterations are key processes in the structuration of soil microbial communities and plant development. In soil, abiotic and biotic factors such as pH, organic matter and vegetation have been extensively studied to govern microbial communities' structure. However, some important biotic interactions are still poorly described. Especially molecules produced during bacterial interactions that affect microbial communities' structure and plant health and growth are still underexplored. To obtain insights of the impact of these interactions, we focused on bacteria that share a habitat with the same abiotic and biotic conditions and that are likely interacting. In order to reach this goal, we isolated bacteria from different grains of soil, described their functional abilities, evaluated the behaviours against each other and their impact on the growth of Populus. In this study, bacteria from a grain of soil had a high functional diversity where few bacteria were interacting. Most interactions were antagonistic and few were strong inhibitions. Moreover, most bacteria altered the root architecture of Populus, and interestingly one Streptomyces strain was able to cause necrosis in the root system
Les minéralisations aurifères de Yaou et Couriège (Bouclier Guyanais) : des modalités de l'enrichissement primaire aux processus secondaires by Vincent Combes( )

1 edition published in 2020 in French and held by 1 WorldCat member library worldwide

Gold deposits located in French Guiana (France, South America) within Rhyacian terranes (2.3-2.05 Ga), are the witnesses of the Trans-Amazonian orogeny. These deposits, in the Guiana Shield, are covered by a dense rainforest where well-developed lateritic profiles leave little outcrop of unaltered bedrock. Considering this specific context, this thesis is interested in defining (i) what are the primary gold mineralisation processes and (ii) what is their preservation and enrichment (or not) during secondary supergene processes and is based on two case studies: the Yaou deposit and the Couriège prospect. At Yaou, intrusive bodies (quartz monzodiorite), mainly hosting gold mineralisation, are aligned along a sinistral shear zone affecting a volcano-sedimentary sequence. A polyphase tectono-magmatic evolution, of 5 deformation phases, is proposed at the scale of the mineralized camp. Associated with this deformation framework are two gold events which control the overall gold budget of the deposit. The intrusion hosting the mineralisation is dated at 2130.6 ± 5.8 Ma (U-Pb on zircon). The modalities of supergene processes are studied at the Couriège prospect, which includes several gold occurrences associated either with pyrite-rich quartz veins within in situ lateritic profiles, or with colluvial and alluvial horizons. Two profiles were studied to assess the role of supergene processes in the modification of primary (hypogene) mineralisation. The Achman Giraud site is characterised by an authigenic alteration profile with gold-bearing quartz veins. The weak vertical and lateral dispersion of gold, the predominantly primary character of the gold grains, and the limited evidence of supergene gold reprecipitation, argue for minor supergene remobilisation without clear evidence for gold enrichment during lateritisation. The Lupe site exposes a gold-bearing detrital horizon truncating a barren lateritic profile. Gold is present as electrum inclusions in partially goethitised detrital pyrite crystals and as free gold grains exhibiting a sub-rounded shape, mechanical transport marks and Ag-depleted rim, suggesting transport and exposure to weathering over significant distance and time
Comportement des ouvrages soumis à des tassements différentiels : Prise en compte des incertitudes by Elio El Kahi( )

1 edition published in 2020 in English and held by 1 WorldCat member library worldwide

The objective of this thesis is to study the behavior of structures subjected to differential settlement, taking into consideration different sources of uncertainties. Ground movements may have different “sources” (origins), such as the influence of nearby excavations (tunnels), and the presence of underground voids (mining subsidence, sinkhole, etc.). These sources will induce the settlement of soil and its displacement. The soil settlement produced by the ground movements will affect the nearby structure, which will cause the structure movement and its possible damage. This thesis, presented in “papers' form” has the intention of evaluating the influence of uncertainties based on analytical, numerical and experimental approaches. At first, this study starts by developing an analytical model to study the effect of some important variabilities/uncertainties (soil profile deformation form, soil behavior (elastic/elastoplastic), variability of building stiffness, etc.). Then, a numerical model is developed in order to confirm some particular results given by the analytical model. Finally, an experimental model is dedicated to characterize one important uncertainty in particular, the variability of the structure stiffness, and to study its influence on the transmission of the ground movement. The main results are the evaluation of confidence intervals that consider the effect of these uncertainties on the structure response affecting the soil-structure interaction (SSI) phenomenon, and the development of a methodology to quantify the impact of uncertainties on the estimation of the deflection transmission rate
Fractionnement anthropique et naturel des isotopes stables du néodyme (Nd) dans l'environnement by Nina Bothamy( )

1 edition published in 2020 in French and held by 1 WorldCat member library worldwide

Distribution et élimination de la chlordécone chez les animaux d'élevage - modélisation des processus by Aurore Fourcot( )

1 edition published in 2020 in French and held by 1 WorldCat member library worldwide

The use of chlordecone (CLD), an organochlorine pesticide used in the French West Indies banana fields between 1972 and 1993, resulted in a long-term pollution of agricultural areas. Animals may be exposed to CLD by ingesting contaminated food or environmental matrices (soil, water or plants). This PhD project is integrated in the objective of securing animal sectors against CLD risk.The aims of this thesis are (1) to provide knowledge on distribution and elimination mechanisms of CLD in farm animals and (2) to develop decision support tools to assist local animal sectors. To this end, in vivo experiments were performed in adult ewes and growing pigs. In pigs, two experiments consisting of monitoring serum and fecal elimination kinetics following a single intravenous administration of CLD or CLDOH (chlordecol) were performed. Non-compartmental and compartmental approaches were used to estimate toxicokinetic parameters of CLD and its metabolites from serum kinetics. Faecal kinetics were used to characterize metabolism of CLD and to quantify its faecal excretion. In ewes, these toxicokinetic data were already available in literature, so the objective was to complete them by characterizing CLD distribution. An experiment involving sequentially slaughters during contamination and decontamination phases allowed to characterize the distribution dynamics of CLD. Correlations between concentrations in tissues were established and CLD half-lives in tissues were calculated. The monitoring of fecal kinetics provided additional knowledge on CLD excretion. All toxicokinetic results obtained in ewes were used to develop a physiologically based pharmacokinetic (PBPK) model to predict CLD concentrations in various tissues. This model will be used to develop decision support tools to assist animal sectors in CLD contaminated areas. An in vivo study is being considered in pigs to characterize the dynamics of CLD tissue distribution and thus be able to develop similar tools to those developed in ewes
Stochastic seismic interpretation of salt bodies : detection, sampling and impact on seismic imaging by Nicolas Clausolles( )

1 edition published in 2020 in English and held by 1 WorldCat member library worldwide

Building a numerical 3D model of the subsurface requires to integrate sparse and ambiguous data. Due to salt tectonics specificities, salt bodies have complex shapes and may present topological singularities. Modeling their geometries is, therefore, difficult, but important as they introduce large physical property contrasts in the subsurface. Seismic imaging is commonly used to map salt and get information about its geometry. Nevertheless, building a seismic image is a long and iterative process, which requires numerous interpretation phases. These interpretations are prone to uncertainties, stemming from the limits of data acquisition and resolution and the assumptions underlying their processing. These uncertainties propagate through the imaging process and impact our understanding and models of the subsurface. Taking them into account is, therefore, crucial during seismic interpretation and requires to be done automatically given the iterative nature of seismic imaging. In this thesis, I am interested in the assessment of structural uncertainties related to the interpretation of ambiguous seismic images of salt tectonics environments. The main contribution of this thesis is a numerical method for stochastically modeling variable shapes of salt bodies and their connectivity. The modeling is based on an a priori definition of the uncertainties, represented as a buffer zone encompassing the salt boundary. The boundary is defined as the combination of a reference scalar field, computed from the buffer zone, and a spatially correlated random field that is used as a perturbation. This implicit formulation allows for the simulation of both varying salt geometries and topologies while ensuring the validity of the simulated boundaries. When the simulated diapir is a bulb detached from its pedestal, a weld is simulated to connect them. The position of the weld is determined from the scalar field representing the salt boundary, to ensure its consistency with the simulated salt bodies. The method is automatic and proposes to integrate punctual information (e.g., well data or manual seismic picks) and, to some extent, prior geological knowledge. The second contribution of this thesis is an application of this method to the characterization of structural uncertainties underlying seismic imaging on a 2D synthetic data set. Starting from a rough buffer zone, I simulate a set of possible interpretations of the salt boundary. I use these interpretations to define a set of equiprobable migration velocity models, that are used in turn to generate as many seismic images. The statistical analysis of this image set, both directly and from derived seismic attributes, permits to highlight the image parts which are most sensitive to migration velocity variations, and provides insights on the nature of the imaged salt bodies. These contributions open new perspectives for uncertainty quantification in an automatic velocity model updating framework in seismic imaging
Development and characterization of chia (Salvia hispanica L.) plant-derived products as natural bioactive compounds by Daria Kuznetcova( )

1 edition published in 2020 in English and held by 1 WorldCat member library worldwide

Omega-3 polyunsaturated fatty acids (PUFA) are important for nutrition and health, by virtue of their importance in lipid homeostasis, and the fact that PUFA deficiencies can increase risk of metabolic syndrome, cardiovascular and neurodegenerative diseases. Chia (Salvia hispanica L.) seeds are rich in PUFA (80%) and contain the highest known levels in plants of the essential omega-3 fatty acid, alpha-linolenic acid (ALA). High degree of unsaturation in edible oils can reduce oxidative stability causing a loss of nutritional value. Nanotechnology can be used to improve chia seed oil quality and safety, increase bioavailability, and expand the scope of applications. Towards this goal, our objective was to prepare and characterize chia seed lipids in the form of nanoliposomes (NL) and nanoemulsions (NE), and to evaluate their potential use as bioactive products. The first step was to characterize lipid fractions. Lipids were extracted from the French ORURO variety of chia seeds using modified Folch method. Ten fatty acid species and six phospholipid (PL) classes were identified in chia seed lipid extract by gas chromatography and LC-MS, respectively, with the highest level of fatty acids being ALA (62%). The presence of a solid residue was detected following evaporation of the solvent to obtain chia seed oil. Analyses by thin layer chromatography and LC-MS demonstrated that this residue contained the polar lipids including PL that were no longer in the chia oil after removal of solvent by evaporation. NE were prepared from chia seed oil and the chia PL-rich solid residue, and NL from the PL-rich solid residue. Physicochemical characterization including analysis of the polydispersity index (PDI), size, and zeta-potential indicated that both NE and NL were monodispersed solutions of stable (low negative zeta potential) particles with a size between 104-118 nm. These preparations were spherical and multilayered (transmission electron microscopy) and remained stable even 5 days after preparation. In addition, enzymatic assay confirmed PL content in both NE and NL. MTT cell viability assay showed little to no cell toxicity (up to 150 µg/mL NE or NL) following 24 h incubation with cultured hepatocytes, neurons, and astrocytes. In conclusion, these results demonstrate the feasibility of using chia lipids for the preparation of stable non-toxic omega-3 PUFA rich NL and NE, which represent potential bioactive vectors for both preventive and therapeutic applications in human health
Étude des interactions entre les particules fines dans les suspensions concentrées pour améliorer la valorisation de minerais complexes durable by Olga Chernoburova( )

1 edition published in 2018 in English and held by 1 WorldCat member library worldwide

Les suspensions minérales de particules fines sont connues pour leur comportement non-Newtonien pendant l'écoulement. Les interactions particule-particule dans de tels systèmes (c'est-à-dire, suspensions minérales) ne sont pas limitées au contact physique, e.g. collision et frottement. La capacité des minéraux de développer une charge dans l'environnement aqueux justifie des comportements différents des systèmes similaires de première vue. C'est à dire qu'étant caractérisées avec la même fraction volumétrique, composition chimique et granulométrie des solides et densité de dispersant, deux suspensions peuvent montrer un comportement rhéologique différent en raison de la chimie de la solution. Dans ce cas, la composition ionique du dispersant définira la charge des particules, et donc le degré d'agglomération/dispersion dans la suspension. Les argiles phyllosilicates sont connues pour être particulièrement problématiques dans les processus de valorisation des minéraux. L'origine de ces minéraux phyllosilicates implique leur inhomogénéité chimique spatiale, ce qui signifie que le bord et la face de la particule montrent des propriétés chimiques et physiques différentes. La présence de tels minéraux dans les dispositifs d'agitation (réservoirs d'agitation, cellules de flottation) est souvent caractérisée par la coexistence de volumes de suspension stagnants et agités, ce qui a un impact négatif sur l'efficacité de l'agitation. Dans ce travail, les suspensions aqueuses diluées de Na-bentonite ont été examinées par vélocimétrie par imagerie par résonance magnétique afin d'étudier l'influence du pH et du type d'électrolyte monovalent sur leur comportement rhéologique local. Les résultats ont montré que les suspensions contenant 0,1% de solide en volume peuvent présenter une bande de cisaillement, une localisation de cisaillement ou aucun phénomène local en fonction de la chimie du milieu de suspension. Il a été suggéré que l'existence d'une «master curve» (ou courbe d'écoulement globale) pour les suspensions diluées dépendait de l'organisation des particules de bentonite dans la suspension, cette organisation est influencée par la chimie de solution et l'historique des contraintes précédentes. Dans l'étape suivante, une seconde et troisieme phases minérales (hématite et quartz) ont été ajoutées dans la matrice de bentonite. L'intérêt dans tels systèmes est lié au comportement sous écoulement des matrices formées avec des types de contacts différents entre particules. Les types de contacts établis dans les suspensions avec une chimie différente du milieu ont été discutés, ainsi que leurs propriétés d'écoulement
Generation of analogues of the anti-tumor polyketide stambomycins by genetic engineering and allied approaches by Li Su( )

1 edition published in 2021 in English and held by 1 WorldCat member library worldwide

The polyketide secondary metabolites of bacteria are a rich source of bioactive agents, with notable applications in anti-infective and anti-cancer therapy. However, their structures often need to be optimized in order to tailor their therapeutic and biophysical properties. The 51-membered macrolide stambomycins, among the largest of known polyketides, were recently discovered by genome mining in Streptomyces ambofaciens ATCC23877, and notably exhibit promising anti-cancer activity. The family encompasses six members which differ from each other in the alkyl functionality at C-26, due to the alternative choice of extender units by an exceptional acyl transferase domain (AT12) of the modular polyketide synthase (PKS) responsible for synthesizing the stambomycin core. Given their enormous size of the stambomycins and the intrinsic promiscuity of AT12, there is substantial interest in accessing ring-contracted and C-26 substituted derivatives of this compounds which might retain the bioactivity of the parental structures, or exhibit improved or even new properties. In this work, we have leveraged our current understanding of modular PKS systems to internally contract the stambomycin assembly line, leading to the successful generation, albeit at low yield, of target smaller derivatives (37-membered 'mini-stambomycins'). By careful analysis, we could identify multiple factors contributing to the low titers, information which should inform future engineering strategies. Furthermore, using a mutasynthesis strategy, we were able to exploit the broad specificity of the AT12 domain to create 6 novel C-26 substituted stambomycin analogues. Finally, we unexpectedly identified three series of novel desferrioxamine siderophores produced by S. ambofaciens. As a number of key metabolites generated in this work have potential interest for therapeutic applications, they will be targeted for purification, structural characterization and biological evaluation
Rock mass mechanical behavior in deep mines : in situ monitoring and numerical modelling for improving seismic hazard assessment by Francesca De Santis( )

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

With the aim of better understanding interactions between stress modifications induced by mining and the generation of seismic activity, a deep area of Garpenberg mine (Sweden) was instrumented by Ineris with microseismic probes and geotechnical cells. Spatiotemporal analysis of recorded seismicity between 2015 and 2016, as well as seismic source parameters, have highlighted two types of seismic rock mass responses: one local and temporally short directly induced by production blasts, the other long-lasting over time and remote from excavations being mainly controlled by geological heterogeneities. Geotechnical data analysis showed the occurrence of aseismic deformations, as well as creep phenomena induced by mining exploitation. In addition, seismic activity decays proportional to the decaying rate of measured strains. This latter observation implies that creep may be another mechanism driving seismicity, in addition to the immediate stress change induced by blasting. In the last part of this thesis, a 3D elasto-plastic geomechanical model has been realized and its results have been compared with geophysical data. This comparison showed that mine-wide numerical models can be suitable for the analysis of mining induced seismicity at large-scale. However, there are some aspects of the induced seismicity that the model cannot fully explain. This is particularly true for remote seismicity occurring at a distance from excavations, while better correlations are found when considering seismicity close to production areas. Results of this thesis demonstrated that a combined approach which associates seismic and geotechnical data with numerical modelling can significantly improve our understanding of the rock mass response to mining. The combination of these methodologies in an integrated approach can significantly reduce their straightforward limitations, which appears evident when these instruments are considered separately
Toxicocinétique de la chlordécone chez la brebis by Maïlie Saint-Hilaire( )

1 edition published in 2018 in French and held by 1 WorldCat member library worldwide

Aux Antilles Françaises, les animaux d'élevage sont susceptibles d'être exposés à la chlordécone (CLD), Polluant Organique Persistant (POP) présent dans leur environnement. Afin de sécuriser les Denrées Alimentaires d'Origine Animale (DAOA) destinées à la consommation humaine, nos travaux ont porté sur l'étude du devenir de la CLD chez la brebis. Les objectifs de ces travaux étaient de comprendre comment s'effectue l'élimination de la molécule depuis l'organisme animal c'est-à-dire de déterminer par quelle(s) voie(s), sous quelle(s) forme (s), en combien de temps, en quelle quantité et par quels mécanismes s'élimine la CLD. Pour cette étude, deux volets ont été considérés : un volet analytique et un volet toxicocinétique. En effet, les méthodes de dosage connues des métabolites de la CLD ne permettaient pas d'obtenir la sensibilité et la fiabilité attendues pour nos travaux. Ainsi, un développement analytique de méthodes de dosage de la CLD et de ses métabolites dans les matrices d'intérêt a été mené. Ces travaux analytiques se sont appuyés sur une méthodologie d'extraction de type Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS), une analyse par chromatographie en phase liquide couplée à la spectrométrie de masse en tandem (LC-MS/MS) et l'utilisation d'étalons internes isotopiques. Ce développement permet de disposer de méthodes de dosage sensibles, rapides et fiables de la CLD et de ses métabolites dans différentes matrices animales. A l'issue de l'étape de développement analytique, les méthodes dans le foie, les fèces et les urines ont été validées à l'aide de profils d'exactitude établis selon la norme V03-110 et le guide SANTE de référence pour les pesticides. Pour exemple, dans la matrice foie, des limites de quantification de 1,36 µg kg-1 PF et de 2,50 µg kg-1 PF respectivement de chlordécone et de chlordécol (métabolite de la CLD) ont été retrouvées. Le deuxième volet de cette thèse s'est appuyé sur deux protocoles toxicocinétiques réalisés chez la brebis. A l'aide de ces expérimentations, il a été possible de combler une partie des lacunes sur la toxicocinétique de la CLD chez la brebis. Nos travaux ont démontré que la CLD est partiellement métabolisée en chlordécol (CLDOH) par la chlordécone réductase dans le foie des brebis. Par la suite, la CLD et le CLDOH peuvent être métabolisés à l'aide d'UDP-glucuronosyl-transferases et de sulfo-transferases en métabolites conjugués de la CLD et du CLDOH (CLD-C et CLDOH-C). Le CLDOH est un métabolite intermédiaire qui n'est quasiment jamais quantifié dans l'organisme animal hormis dans le tissu gras. L'élimination de la CLD se fait majoritairement via les fèces : 1/3 de la molécule parent CLD est éliminé sous forme de CLD et 1/6 est éliminé sous forme de CLDOH. La voie urinaire est une voie mineure d'élimination de la CLD. A l'aide de ces travaux, un modèle compartimental a été proposé. Sur la base de ce modèle, des travaux de modélisation seront possibles et permettront la proposition et la mise en place de stratégies de décontamination des ovins aux Antilles Françaises
 
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Alternative Names
École doctorale 607

École doctorale Science et ingénierie des ressources naturelles

École doctorale SIReNa

ED 607

ED607

SIRENa

Languages
French (11)

English (9)