ED Mathématiques et Informatique
Exploring concrete and immersive visualizations to communicate environmental impacts of daily actions
by Aymeric FERRON (LaBRI - Laboratoire Bordelais de Recherche en Informatique)
The defense will take place at 9h30 - Salle Ada Lovelace Centre Inria de l'université de Bordeaux 200 avenue de la Vieille Tour 33405 TALENCE
in front of the jury composed of
- Yvonne JANSEN - Chargée de recherche - CNRS - Directeur de these
- Tim DWYER - Professeur - Monash University - Rapporteur
- Laurence NIGAY - Professeure des universités - Université Grenoble Alpes - Rapporteur
- Raimund DACHSELT - Full professor - Dresden University of Technology - Examinateur
- Anastasia BEZERIANOS - Professeure des universités - Université Paris Saclay - Examinateur
- Martin HACHET - Directeur de recherche - Inria - CoDirecteur de these
Understanding the environmental impacts of daily actions is challenging: the data is complex and rarely communicated in a comprehensible way. Yet, improving public knowledge and awareness of unsustainable behaviours is essential to make more sustainable choices, both individually and collectively. To do so, it is important to communicate about environmental impacts with tools sparking interest and fostering engagement. In this thesis, we explore concrete and immersive visualization to communicate impacts of daily actions. First, we introduce a concrete visualization communicating about three planetary boundaries represented thanks to a mini-world mimicking biophysical processes of the Earth. Next, we report on a controlled study investigating the effects of augmented reality (AR) and concrete visualizations on message credibility of environmental impacts, as well as on user engagement—finding that concrete AR visualizations can substantially increase engagement without threatening credibility. Then, we report on a second controlled study investigating the impact of enactment and quiz-based gamification on the memorability of greenhouse gas emissions in virtual reality—suggesting that gamification supports memory retention while enactment increases intrinsic motivation and flow state. Finally, we introduce AR visualizations spanning dozens of meters to convey datasets containing large order of magnitude data, and propose a design space exploring the use of motion to support progressive data exploration. Taken together, our contributions suggest that concrete and immersive visualizations are a promising direction for environmental communication, opening an engaging and credible alternative to conventional chart-based representations.
ED Sciences Chimiques
Role of emerging contaminants in promoting horizontal transfer of antimicrobial resistance genes: a multiscale approach in environmental context
by Ana REY SOGO (Environnements et Paléoenvironnements Océaniques et Continentaux)
The defense will take place at 11h00 - Aula A1 Salón de Grados de la Facultad de Ciencia y Tecnología University of the Basque Country (UPV/EHU) Faculty of Science and Technology, Sarriena Auzoa, 48940 Santsoena, Biscay
in front of the jury composed of
- Eric FOUQUET - Professeur des universités - Institut des Sciences Moléculaires (ISM), Université de Bordeaux - Examinateur
- Elisabeth GROHMANN - Professeure - Berlin University of Applied Sciences, Faculty of Life Sciences and Technology, Department of Microbiology, Berlin, Germany - Rapporteur
- Manel CAMPS - Full professor - UC Santa Cruz - Examinateur
- Nestor ETXEBARRIA LOIZATE - Full professor - Department of Analytical Chemistry Faculty of Science and Technology – Plentzia Marine Station (PIE) University of the Basque Country / Euskal Herriko Unibertsitatea - Examinateur
- Matxalen LLOSA BLAS - Professeure des universités - Facultad de Medicina, University of Cantabria (UC) - Rapporteur
The global dissemination of antimicrobial resistance (AMR) through horizontal gene transfer (HGT), and specifically through conjugative transfer, represents one of the most urgent challenges in environmental microbiology and public health. While antibiotics have long been recognized as drivers of AMR selection and spread, the role of contaminants of emerging concern (e.g., industrial chemicals, disinfectants, personal care products) as promoters of bacterial conjugation at environmentally relevant concentrations remains insufficiently understood. This thesis addresses that gap through a multiscale, integrative approach combining machine learning (ML)-based predictive modelling, in vitro experimentation across three conjugation systems, and in situ field assessment in a wastewater-influenced estuary. In the first chapter, a suite of ML models (Linear Regression, Random Forest, and XGBoost) was developed and evaluated using a curated dataset of published effects of chemical stressors on conjugation experiments. The best-performing model, XGBoost, achieved an internal validation R² of 0.719, demonstrating meaningful predictive capacity. Feature importance analysis revealed that chemical concentration, bacterial species and structural fingerprints were the dominant predictors. These findings establish a framework for HGT risk assessment and identify the boundaries of current predictive capacity, underscoring the need for larger, more homogeneous experimental datasets to extend model applicability. In the second chapter, the effects of twelve CECs from six functional groups on conjugative transfer were characterized using two intraspecies Escherichia coli mating systems sharing the same recipient HMS174 but differing in donor background and plasmid incompatibility (Inc) group (IncF/K12 and IncP/UB1637). Both systems responded to CEC exposure at 0.001–0.01 µg/mL, but the IncP system consistently showed stronger and more reproducible induction. This differential sensitivity was attributed to plasmid type and mechanistically explained by three factors: the higher basal transfer frequency of IncF, leaving less apparent fold-change induction; cell population heterogeneity; and the plasmid intrinsic regulatory system. Molecular mechanisms were further elucidated for individual CECs, demonstrating compound-specific pathways. In the third chapter, the investigation was extended to an in situ environmental context, characterizing the mobilizable plasmidome at four sampling points spanning wastewater treatment plant (WWTP) effluents and pristine receiving waters. Integration of captured plasmids, qPCR of AMR-related genes and site chemical context demonstrated that WWTP effluent discharge locations harbored high plasmid capture rates and diversity. Furthermore, exposure of the in vitro IncF/HMS174 conjugation system to WWTP effluent modulated conjugative transfer, providing a mechanistic link between complex chemical stressor mixtures and in situ HGT dynamics. Collectively, this thesis establishes that CECs at environmentally relevant concentrations constitute a modest but real risk factor for conjugation-driven AMR dissemination, whose magnitude is determined by the interplay of chemical identity, plasmid regulatory architecture, and population-level heterogeneity. The compound-specific mechanistic diversity uncovered highlights the importance of studying individual chemicals, while exposure to effluent mixtures and the in situ mobilizable plasmidome underscore that real-world risk is shaped by chemical complexity and ecological context in ways that single-compound laboratory-based experiments cannot fully capture. These findings argue for the integration of HGT-promoting potential into environmental risk frameworks, and for the development of standardized, multi-plasmid conjugation assays as regulatory tools for assessing chemical threats to the environmental resistome.
ED Droit
Corporate Environmental Responsibility: Between the Pursuit of Profit and Greenwashing
by Hanif OUBROU (CENTRE DE RECHERCHES ET DE DOCUMENTATION EUROPÉENNES ET INTERNATIONALES)
The defense will take place at 14h00 - Salle des thèses, Bâtiment C, 16 Avenue Léon Duguit, 33600 Pessac
in front of the jury composed of
- Hubert DELZANGLES - Professeur - Sciences Po Bordeaux - Directeur de these
- Julien BéTAILLE - Professeur - Université de Pau Pays de l'Adour - Rapporteur
- Grégoire LERAY - Professeur - Université Côte d'Azur - Rapporteur
- Frédéric MARTY - Directeur de recherche - Université Côte d'Azur - Examinateur
- Alexandre ZABALZA - Professeur - Université de Bordeaux - Examinateur
Environmental degradation is fundamentally linked to economic activity. In this context, the company, in particular the large multinational company, is now called upon to integrate environmental protection into the conduct of its activities. This study seeks to apprehend this paradox in legal terms by analysing the two major criticisms directed at the modern company: the exclusive and relentless pursuit of profit, and greenwashing. The first part explores the logic of profit through a reflection on the human being himself. The company is not an abstract entity: it extends the anthropological drivers of man, torn between self-interest and altruism. The major doctrines of corporate social responsibility, whether profit maximisation or stakeholder theory, replay at the level of the company the fundamental tension between self-interest and altruism that runs through the human being, and thus his responsibility in climate disruption. In this respect, new legal instruments, such as the "raison d'être", the "entreprise à mission", the corporate duty of vigilance, environmental litigation, Say on Climate, and so forth, testify to the attempt to channel this tension between environment and profit. The second part focuses on the phenomenon of greenwashing, in which the company is no longer defined solely by its practices and by what it truly is, but also by the environmental image it claims. By regulating the gap between the company's acts and discourse, the law constitutes a tool intended to establish a requirement of truthfulness. This requirement is first expressed through mechanisms of advertising self-regulation, both flexible and pedagogical, which allow for an in-depth analysis of what greenwashing entails. It is also expressed through recourse to litigation before the courts, as well as through the adoption of texts strengthening the legal liability attached to environmental claims. Ultimately, this thesis shows that the criticism of an exclusive and relentless pursuit of profit and that of greenwashing converge in the same interrogation concerning the truth and responsibility of the company. Between the pursuit of profit and the consideration of environmental issues, communicational appearance and environmental reality, the law appears as an instrument of change. Its role is not to suppress the tension between economy and environment, but to make possible an alignment between what the company is, what it does, and what it says.
ED Sciences de la Vie et de la Santé
Hematopoietic stem cell self-renewal mecanisms
by Arthur POULET (BoRdeaux Institute of onCology)
The defense will take place at 13h30 - Amphi BBS Bât BBS, 2 Rue Hoffmann-Martinot, 33000, Bordeaux
in front of the jury composed of
- Marie-Laure ARCANGELI - Chargée de recherche - Institut Gustave Roussy - Rapporteur
- Christine DIDIER - Chargée de recherche - Centre de Recherches en Cancérologie de Toulouse - Rapporteur
- Eirini TROMPOUKI - Directrice de recherche - Institute for Research on Cancer and Aging, Nice (IRCAN) - Examinateur
- Philippe DE DEURWAERDERE - Professeur des universités - Université de Bordeaux - Examinateur
The production of mature blood cells is ensured throughout life by a rare cell population: hematopoietic stem cells (HSCs). Through their self-renewal and multipotency, they ensure the long-term maintenance of the hematopoietic system and hold critical therapeutic importance, particularly in the treatment of hematological disorders. The balance between quiescence, self-renewal, and differentiation is tightly regulated, and recent studies have highlighted the pivotal role of metabolism in this regulation. A comparative metabolomic analysis previously conducted in our laboratory identified N-acetyl-L-aspartate (NAA) as one of the metabolites up to ten times more abundant in proliferative fetal liver HSCs compared to quiescent adult bone marrow HSCs, suggesting a role in expansion. While this metabolite is well known for its abundance in the brain, its involvement in hematopoiesis remains poorly described, and the initial characterization of the Nat8l-KO model showed that it is not essential for murine hematopoiesis under steady-state conditions, suggesting that its role might be specifically linked to expansion contexts, such as hematopoietic stress. The aim of this thesis was to test this hypothesis by assessing the role of NAA in HSC adaptation to various hematopoietic stresses. The first part of this work focused on developing tools for the precise identification of the stem cell compartment under stress conditions. The Pdzk1ip1-EGFP reporter model, specifically enriched in HSCs, was characterized under both basal and stress conditions. This model enabled HSC identification independent of variations in classic surface markers, such as c-Kit, whose expression can be modulated under stress. The second part assessed the impact of NAA loss in the Nat8l-KO model. The HSC compartment appears preserved at steady state and is not significantly altered after acute or chronic LPS-induced inflammatory stress. In contrast, under repeated myeloablative stress with 5-FU, Nat8l-KO mice display reduced survival and a smaller HSC pool, accompanied by increased transcriptomic signatures of oxidative and inflammatory stress. During physiological aging, NAA loss leads to an overall reduction of the HSC compartment, as well as impaired long-term reconstitution capacity in transplantation assays. Taken together, these results indicate that NAA is not required for steady-state maintenance of the stem cell compartment but becomes critical when HSCs are subjected to sustained or repeated regenerative demand. The convergence of data obtained under chronic myeloablative stress and during aging positions NAA as a metabolic player in hematopoietic plasticity. By characterizing the metabolic regulation of HSC expansion and self-renewal under stress, this work provides valuable insights into the challenge of ex vivo HSC expansion and the optimization of their use in transplantation and regenerative medicine.
Characterization of the immune microenvironment in high risk non-muscle-invasive bladder cancer
by Clément KLEIN (Immunologie Conceptuelle, Expérimentale et Translationnelle)
The defense will take place at 14h00 - Salle de Conférences Centre d'Appui à la Recherche et Formation Université de Bordeaux - Campus Carreire 146 Rue Léo Saignat, 33000 Bordeaux
in front of the jury composed of
- Grégoire ROBERT - Professeur des universités - praticien hospitalier - CHU de Bordeaux - Directeur de these
- François AUDENET - Professeur des universités - praticien hospitalier - Hôpital européen Georges-Pompidou - Rapporteur
- Céline COLACIOS - Professeure des universités - Centre de Recherche en Cancérologie de Toulouse (CRCT) INSERM UMR-1037 - Rapporteur
- Alexandra MASSON-LECOMTE - Professeure des universités - praticienne hospitalière - Hôpital Saint Louis - Examinateur
Bladder cancer is one of the most common urological malignancies, with approximately 75% of cases diagnosed at the stage of non–muscle-invasive bladder cancer (NMIBC). Among these, high-risk tumors are characterized by a significant risk of recurrence and progression to muscle-invasive disease, which is associated with a poorer prognosis. Despite the effectiveness of intravesical Bacillus Calmette–Guérin (BCG) therapy, a substantial proportion of patients experience treatment resistance or tumor progression, highlighting the critical role of the tumor microenvironment and immune escape mechanisms in disease progression. The aim of this thesis was to better characterize the immune microenvironment of urothelial bladder cancer, particularly in high-risk NMIBC, in order to identify the immunological mechanisms involved in tumor progression and therapeutic resistance. In the first study, a targeted transcriptomic analysis of the tumor immune microenvironment was performed using tumor samples from patients with bladder cancer. By integrating immune signatures (including gene signatures associated with adaptive immunity, myeloid cell infiltration, and immune checkpoint expression) and transcriptional modules, this approach revealed a marked heterogeneity in the tumor immune landscape. Early-stage tumors generally exhibited stronger adaptive and cytotoxic immune signatures, whereas more advanced stages were associated with increased myeloid, immunoregulatory, and proliferative programs. Furthermore, the coordinated expression of several immune checkpoint molecules, including PD-L1, TIGIT, and LAG-3, increased with tumor stage, suggesting the concomitant activation of both immune effector and inhibitory mechanisms during tumor progression. In the second study, we investigated the functional role of immunosuppressive myeloid cells in tumor plasticity. Using in vitro co-culture models, we demonstrated that suppressive cells derived from human monocytes promote the acquisition of cancer stem cell–like properties in bladder tumor cells. This effect relies on direct cell-to-cell contact and involves the coordinated activation of inflammatory pathways and epithelial–mesenchymal transition programs, notably through TNF-α and TGF-β signaling. These findings provide mechanistic evidence linking immune suppression to the acquisition of more aggressive tumor phenotypes. Overall, these studies highlight the central role of interactions between tumor cells and myeloid immune cells in bladder cancer progression. They suggest that these immune populations not only contribute to immune evasion but also actively promote tumor plasticity and the emergence of cancer stem cells. These findings suggest new therapeutic strategies aimed at simultaneously targeting immunosuppressive mechanisms and tumor plasticity programs to improve the management of high-risk NMIBC.