ED Sciences Chimiques
Study of the surface, interface, and rheological behavior of an ionically conductive slurry for next-generation all-solid-state batteries
by Nizar GHAZOUANI (Laboratoire du Futur)
The defense will take place at 14h00 - Amphithéâtre CRPP Centre de Recherche Paul Pascal UMR5031 CNRS / Université de Bordeaux 115 avenue Dr Schweitzer 33600 PESSAC
in front of the jury composed of
- Yaocihuatl MEDINA-GONZALEZ - Directrice de recherche - CNRS - Directeur de these
- Annie COLIN - Professeure - École supérieure de physique et de chimie industrielles de la ville de Paris (ESPCI Paris) - Rapporteur
- Jean-François LAHITTE - Maître de conférences - Université Toulouse 3 : Paul Sabatier - Rapporteur
- Mona TREGUER-DELAPIERRE - Professeure - Université de Bordeaux - Examinateur
All-solid-state batteries (ASSBs) offer enhanced safety and energy density, with sulfide solid electrolytes like Li₆PS₅Cl emerging as promising candidates due to their high ionic conductivity and compatibility with low-temperature processing. However, challenges in formulating thin, mechanically robust solid electrolyte films persist due to the brittleness and solvent sensitivity of Li₆PS₅Cl. This sensitivity is usually studied from a performance or degradation point of view. This work investigates the physicochemical interactions between Li₆PS₅Cl, polymeric binder SEBS, and various organic solvents to understand and optimize slurry formulation to establish clear design principles. A comprehensive study of solvent reactivity, dispersion behavior, and binder solubility was conducted using solubility modeling, spectroscopic analysis, and rheological characterization. It was found that Li₆PS₅Cl reactivity is governed not only by solvent polarity but by a combination of dielectric constant, donor number, and acceptor number, enabling a new solvent classification model that predicts stability, dispersion, or reactivity. Moreover, the dispersion of argyrodite particles in different inert solvents resulted in either a deagglomerated compact slurry or a loose agglomerated suspension. The resulting materials exhibited two distinct rheological behaviors, due to frictional properties for well-dispersed slurries and cohesive interactions in agglomerated suspensions. Rheological tests also confirmed that SEBS enhances flow homogeneity and increases maximum packing, though its effectiveness is solvent-dependent. Finally, a comparative analysis of different Li₆PS₅Cl grades revealed that synthesis-dependent differences in particle size, surface chemistry, and carbon content strongly affect rheological behavior and can be optimized for a better processability. Altogether, this study delivers a robust physico-chemical framework for solvent and binder selection, leading to optimized slurry processability and improved electrolyte performance. These insights advance the fundamental understanding of particle-binder-solvent interactions, directly informing scalable manufacturing strategies for high-performance ASSBs.
ED Sciences de la Vie et de la Santé
Study of the cellular signaling pathways modulated by bacterial genotoxins
by Ruxue JIA (BoRdeaux Institute of onCology)
The defense will take place at 13h30 - Amphithéâtre 7 Bâtiment Biologie Bordeaux Santé, Université de Bordeaux, Campus Carreire, 2 rue du Docteur Hoffman Martinot, 33000 Bordeaux
in front of the jury composed of
- Armelle MENARD - Ingénieure de recherche - BRIC, Université de Bordeaux - Directeur de these
- Gladys MIREY - Directrice de recherche - TOXALIM, Université de Toulouse - Rapporteur
- Hang NGUYEN - Chargée de recherche - M2iSH, Université Clermont Auvergne - Rapporteur
- Jean-Philippe NOUGAYREDE - Directeur de recherche - institut de Recherche en Santé Digestive (Inserm, INRAE, ENVT, UT3 Paul Sabatier) - Examinateur
- Fabien DARFEUILLE - Directeur de recherche - ARNA, Université de Bordeaux - Examinateur
Certain bacteria producing Cytolethal Distending Toxin (CDT) and colibactin are linked to cancers, particularly colorectal cancer. These toxins directly damage host cell DNA and impair the DNA damage response, leading to genomic instability and mutation accumulation that can be transmitted to daughter cells, potentially promoting carcinogenesis. These genotoxins are increasingly recognized for their critical roles in manipulating host cellular signaling pathways. The aim of the thesis was to evaluate the modulation of two major signaling pathways in the host cellular response to genotoxin exposure: the Hippo-YAP/TAZ-TEAD pathway and the Wnt/β-catenin pathway. The Hippo signaling pathway, which plays a crucial role in regulating cell proliferation, survival, and genomic stability. Some phenotypes induced by these genotoxins (actin cytoskeleton remodeling, stress fibers accumulation, disturbance of focal adhesion, cell-cell junctions' disassembly, increased ploidy and genome instability, endoreplication) are known to involve the Hippo signaling pathway. This suggests a link between some of the effects induced by these toxins and Hippo signaling pathway. We investigated the Hippo pathway in normal and cancer-derived epithelial intestinal and hepatic cell lines following exposure to CDT/CdtB and colibactin. We demonstrated that active CdtB subunit of CDT modulates the expression of transcripts and proteins related to the Hippo pathway's central downstream transcriptional coactivators YAP/TAZ. Exposure to CDT/CdtB led to increased TEAD-mediated transcription , as confirmed by the upregulation of direct TEAD target genes. Inhibition of YAP/TAZ binding to TEADs using verteporfin and K-975 dampened the effects of CdtB, particularly regarding DNA damage and repair, and increased ploidy. These findings suggest that YAP/TAZ-TEAD signaling is involved in increased ploidy in cells that survive DNA damage induced by CDT/CdtB. Furthermore, exposure to colibactin, a genotoxic metabolite produced by Escherichia coli, induced similar effects. Overall, our data indicate that infection with genotoxin-producing bacteria involves the YAP/TAZ-TEAD signaling pathway to regulate ploidy following DNA damage in epithelial cells. The second part of our study focused on how bacterial genotoxins affect the Wnt/β-catenin signaling pathway, another key regulator of cell fate, proliferation, and differentiation. Following CDT/CdtB exposure, we observed increased phosphorylation of β-catenin at serine 552, accompanied by its loss from adherens junctions, leading to destabilization of cell-cell junction. This resulted in the release of β-catenin into the cytoplasm and nucleus translocation. Ultimately, this led to the activation of TCF/LEF-dependent transcription, a crucial downstream event of Wnt/β catenin signaling, as well as the upregulation of some direct β catenin target genes. Importantly, inhibition of AKT signaling, either directly with MK 2206 or indirectly through AMPK activation by metformin, reduced many of these CDT/CdtB-induced effects. These effects include β-catenin Ser552 phosphorylation and its nuclear accumulation, which in turn decreased TCF/LEF transcriptional activity. Additionally, both MK 2206 and metformin protected from CdtB-induced disruption of cell-cell junctions, increased nuclear accumulation of SNAIL, enhanced matrix degradation, and the augmented cellular motility. The use of these inhibitors revealed that phosphorylation of β-catenin at serine 552 following CdtB exposure involves AKT activation. Overall, these data show that infection with genotoxin-producing bacteria regulates some epithelial to mesenchymal transition features through β catenin-dependent signaling. Together, these findings demonstrate that bacterial genotoxins modulate host cell signaling through both the Hippo-YAP/TAZ-TEAD and Wnt/β-catenin pathways.
ED Sciences Physiques et de l'Ingénieur
Origin and search for complex molecules in protostars - Statistical and AI approaches to extract information
by Nina KESSLER (Laboratoire d'Astrophysique de Bordeaux)
The defense will take place at 14h00 - Salle Univers Laboratoire d'Astrophysique de Bordeaux Allée Geoffroy Saint-Hilaire - Bât. B18N CS 50023 33615 PESSAC CEDEX
in front of the jury composed of
- Timea CSENGERI - Chargée de recherche - Université de Bordeaux - Directeur de these
- Charlotte VASTEL - Astronome - Université Paul Sabatier Toulouse - Rapporteur
- Marc HUERTAS-COMPANY - Maître de conférences - Université Paris Diderot - Rapporteur
- Ana LOPEZ-SEPULCRE - Astronome adjointe - Université Grenoble Alpes - Examinateur
- Hervé BOUY - Professeur des universités - Université de Bordeaux - Examinateur
- Sylvain BONTEMPS - Directeur de recherche - Université de Bordeaux - CoDirecteur de these
A substantial fraction of complex organic molecules (COMs) found in the gaseous envelope around massive protostars (hot core) are thought to be synthesized on the surface of dust grains and in their ice mantle, and then desorbed near protostars. Then, through chemical reactions that can also take place in the gas phase, the medium is enriched by other complex molecules. As a result, the millimeter spectra of hot cores are chemically rich and provide us with information about the physics and chemistry of the medium. In addition, some COMs are considered prebiotic because their functional group plays an important role in the functioning of life as we know it. We are therefore seeking to understand the origin of the chemical diversity that can develop in hot cores, the role of interactions between physics and chemistry, and the way in which this molecular content evolves in an environment affected by feedback from the protostar. The detection of chemical species and the determination of their underlying physical parameters are based on iterative methods of fitting synthetic spectra assuming local thermodynamic equilibrium (LTE). However, this procedure can be time-consuming and restrictive for chemically rich sources, especially in the context of broad band spectroscopic data from state-of-the-art telescopes. This makes it difficult to carry out statistical and systematic studies of the chemistry of star-forming regions. To address this problem, we have developed a machine learning-based method to automate the detection and identification of the spectroscopic signature of 20 molecules, including several COMs, from their transitions observed in the millimeter range. To do this, a training dataset representative of rich sources was constructed using LTE models, and the architecture of a convolutional artificial neural network (CNN) was developed using the CIANNA framework. The resulting CNN-model is capable of extracting useful information and analyzing rotational emission spectra to provide a detection probability on molecular content in a robust manner for synthetic data. The predictions for rich hot core spectra confirm that the application of the CNN-model can be generalized to observational spectra. To go one step further, we investigate the interpretability of such models with the aim to understand how molecules are detected. For this purpose we perform an occlusion analysis of the CNN-model in order to reveal which transitions it favors and what impact they have on the predictions. This thesis also includes an analysis of the CygX-N53 source using pilot data from the NASCENT-Stars observational program obtained with the NOEMA millimeter interferometer. We are interested in the two most massive protostars of CygX-N53, which originate from the same gas reservoir, but whose physical properties suggest that they have different evolutionary stages. To advance our understanding of this region, we have carried out an inventory of the COMs whose emission has been detected in order to study the chemical differentiation around these protostars, while exploring the extent to which the CNN-model can facilitate the analysis of the molecular content in this context. This work paves the way for the use of CNNs to study the spectra of hot cores. We intend to generalize this method to apply it to other frequencies, and also to estimate the physical parameters associated to molecules, with the aim of extending our knowledge on the chemistry of hot cores.
Assisting humans through adaptive haptic guidance, application to remote-controlled vertical farming
by Alexis BOULAY (Institut national de recherche en informatique et en automatique - Bordeaux - Sud-Ouest)
The defense will take place at 10h00 - 0 108 École Nationale Supérieure de Cognitique, 109 avenue Roul, 33405, Talence CEDEX
in front of the jury composed of
- David DANEY - Directeur de recherche - Centre Inria de l'Université de Bordeaux - Directeur de these
- Claudio PACCHIEROTTI - Chargé de recherche - IRISA - CNRS - Rapporteur
- Margot VULLIEZ - Chargée de recherche - Centre Inria de l'Université de Bordeaux - CoDirecteur de these
- Arnaud LELEVé - Professeur des universités - Ampère - Insa Lyon - Rapporteur
- Marie-Aude VITRANI - Professeure des universités - ISIR - Sorbonne Université - Examinateur
- Franck GEFFARD - Ingénieur de recherche - CEA - LIST - Examinateur
In vertical farming, teleoperation enables human skills to be leveraged for plant manipulation while maintaining a pest and disease free growing environment. A key component of teleoperation is the exchange of information between the operator and the robotic system such as visual feedback (video streams) and haptic feedback (physical interaction cues with the environment). This thesis focuses on the use of haptic feedback through haptic guidance. Haptic guidance is designed to assist the operator in controlling the robot by encouraging movement in a specific direction, along a predefined path, or by restricting access to certain areas through guiding forces. It relies on two main components: a guidance model and a virtual object. The model determines a force profile based on the distance to the virtual object. For haptic guidance to be effective, both elements must be carefully defined; otherwise, the guidance may negatively impact task performance. Since these components are usually pre-defined, adapting them in dynamic environments like vertical farming can be challenging. Our goal is to develop a generic and online-adaptable haptic guidance approach that adjusts in real time based on the complexity of both the task and the environment by evaluating the human-guidance interaction. Existing literature identifies three commonly used guidance models: the spring damper, the guiding tube, and the potential field. Each has distinct characteristics, making it advantageous to use different models on the same complex task. To unify these approaches, we developed a generic model ruling guidance that replicates the behavior of all three and allows for continuous transitions between them. A user study validated the relevance of this model, showing that the choice of guidance depends on environmental clutter. The study also introduced objective metrics for assessing human-guidance interaction across four criteria: performance, safety, comfort, and trust. Using these metrics particularly variations in guiding force we propose several strategies to dynamically adapt the ruling guidance model. Additionally, we introduce a new haptic guidance framework called dual adaptable. Formulated as an optimization problem, this model generates guiding forces that enhance operator comfort while accounting for environmental complexity by simultaneously considering multiple types of virtual objects. However, dynamic adaptation of the guidance model alone is not sufficient. Poorly defined virtual objects can still negatively impact task performance. To support real-time adaptation in response to environmental or task changes, we propose two new types of adaptable virtual objects. The elastic guide is a deformable path that responds to operator movements, while the predictive guide continuously replans itself based on the robot's current position and task requirements. Finally, this thesis introduces a generic, online-adaptable haptic guidance framework, covering both the guidance model and the definition of virtual objects.
ED Sociétés, Politique, Santé Publique
Comparative Analysis of Global Sports Brands
by Ricardo RUBEIZ (Laboratoire Cultures, Education, Sociétés)
The defense will take place at 14h00 - Salle A Universite de Bordeaux - STAPS
in front of the jury composed of
- Jean-François LOUDCHER - Directeur de recherche - Université de Bordeaux - Directeur de these
- Elie MOUSSA - Associate Professor - Universite de Balamand - CoDirecteur de these
- Christian VIVIER - Professeur des universités - Universite Marie & Louis Pasteur - Rapporteur
- Sorina CERNAIANU - Professeur des universités - Université de Craiova - Rapporteur
- André SUCHET - Chargé de recherche - Université de Bordeaux - Examinateur
- Kilian MOUSSET - Maître de conférences - UFR STAPS - Laboratoire L-VIS. Universite de Claude Bernard - Lyon 1 - Examinateur
The main and key objective of this Doctoral research is to establish costumers' purchase behavior towards leading International sportswear brands (Adidas and Nike). The aim is to study and understand from a marketing, social representation, behavior as well as strategic point of view, the perception and how consumers (Sportive subjects who are physical education students vs. Non-Sportive subjects who are students of different majors, both from various different universities in Lebanon) act or react towards those well-known international sports brands. We want to analyze both the supply - by examining the strategic positioning of companies on different markets - as well as the demand by identifying the psychological dimensions on which they are based. The research will cover a great scope of knowledge to illuminate behavior taking place within a society characterized by the combination of western and eastern influences, a multi-religious society and an extensiveness of political and economic instabilities, thus defining consumers' behavior into the Lebanese market context and from a perspective of a country that researches have not studied or explored before. This will aid companies in gathering information and acquiring insights in order to understand and to plan gaining popularity in Lebanon. We used the methodology of the social representations and the quantitative approach in addition to considering other main elements pertaining to our study like Brand Behavior, Brand Equity, Consumer Brand Identity and Brand Awareness in relation to both Personal Identity and Social Identity. Results revealed that the differentiation of the brands positioning depends on legitimate factors of the market like Cost and Pricing, Image and Association and Sponsorship to name some that affects either positively or negatively the purchasing behavior, attitude and decisions. Results have also revealed the importance of other factors like Choice of products / Specificity which also plays a role. Finding any type of product wanted at a specific brand proves to have a great impact in future choices. Even if any of the two brands is associated with more specificity towards the technical part, yet wide choices still influence in the decision making. Some factors like the availability of data, sample, number of subjects and others had limitations on the study. The fact that those limitations had an impact on the results attained made it an exploratory study that may be further developed and covered in future studies. As a perspective, future studies should further cover and emphasize on the purchasing aspect of behavior and its product of changes or beliefs across different factors like gender differences, social orientations, culture, socio-economic situations and religion.