ED Mathématiques et Informatique
Towards secure cluster architectures for HPC workflows
by Lise JOLICOEUR (LaBRI - Laboratoire Bordelais de Recherche en Informatique)
The defense will take place at 16h00 - Salle Ada Lovelace INRIA de Bordeaux, 200 avenue de la Vieille Tour, 33405 Talence
in front of the jury composed of
- Raymond NAMYST - Professeur - Université de Bordeaux - Directeur de these
- Adrien LEBRE - Professeur - IMT Atlantique - Rapporteur
- Christian PEREZ - Directeur de recherche - INRIA - Rapporteur
- Christophe CÉRIN - Professeur - Université Sorbonne Paris Nord - Examinateur
- Pierre RAMET - Professeur - Université de Bordeaux - Examinateur
- Edgar A. LEON - Computer scientist - Lawrence Livermore National Laboratory - Examinateur
The diversification of high performance computing (HPC) workloads and the development of heterogeneous workflows involving HPC, artificial intelligence and machine learning (AI/ML), as well as in-situ analysis, have challenged the typical architecture of HPC clusters. Modern HPC workflows increasingly rely on services and cloud-native applications that are not typically sup- ported on HPC environments. Cloud computing has historically been the platform of choice for running services, leading to the development of a rich ecosystem of cloud-native software. At the same time, it is increasingly supporting HPC applications by offering HPC-grade hardware and batch scheduling through either standard HPC or cloud-native tools. Driven by the converging needs of both communities, there is a growing interest in a "best of both worlds" architecture that supports both HPC and cloud-native applications within the same environment, without compromising on performance, security, and usability. Those efforts are commonly referred to as converged computing. This thesis explores multiple approaches to converged computing for enabling the deployment of cloud-native workloads on HPC clusters. We study two approaches based on deploying on-demand Kubernetes clusters on HPC resources offering different trade- offs in terms of resource management flexibility and supported Kubernetes capabilities. For our Towards secure cluster architectures for HPC workflows imain contribution, we create a container network to provide isolation between users, as well as flexibility and security for deploying service-oriented applications while being transparent for end-users. We implemented this network in the pcocc container engine and found no signifi- cant impact on the performance of MPI applications due to the container network. This novel approach demonstrates that network virtualization can increase flexibility on HPC clusters and enable cloud-native workloads without impacting the performance of standard HPC workloads.
ED Sciences Chimiques
Innovative methods for the efficient and economical introduction of oxygen isotopes
by Alexandra DOUSSOT (Institut des Sciences Moléculaires)
The defense will take place at 9h30 - Salle de conférence, troisième étage ISM UMR 5255, Bât A12, 351 Cours de la Libération 33405 - Talence
in front of the jury composed of
- Philippe HERMANGE - Maître de conférences - Université de Bordeaux - Directeur de these
- Brigitte BIBAL - Professeure - Université de Bordeaux - Examinateur
- Danielle LAURENCIN - Directrice de recherche - Université de Montpellier - Examinateur
- Davide AUDISIO - Directeur de recherche - CEA Institut des Sciences du Vivant Frédéric Joliot - Rapporteur
- Zacharias AMARA - Maître de conférences - Conservatoire national des arts et métiers - Rapporteur
Oxygen is a ubiquitous element in organic chemistry, present in a wide variety of functional groups. Its isotopic labeling plays a crucial role in gaining a detailed understanding of chemical and biological mechanisms. The most common sources, [*O]H₂O and [*O]O₂, remain expensive and often require harsh experimental conditions, restricting their use to simple substrates. In addition, the reversible isotopic exchange processes involved frequently lead to a loss of enrichment. In this context, this PhD work focuses on developing new organic synthesis approaches to efficiently and economically produce complex *O-labeled molecules of high added value, suitable for mechanistic investigations. Building on this strategy, attention was given to the controlled generation of isotopically labeled singlet oxygen, a highly reactive species of major importance in biology and medicine, particularly in photodynamic therapy. The release of singlet oxygen was envisioned through the chemically or thermally induced cycloreversion of endoperoxides. Several molecular architectures were explored, based on 1,4-dimethylnaphthalene or on constrained systems derived from 2-pyridone and metacyclophane frameworks. Despite significant synthetic challenges, a tricyclic compound could be obtained via an intramolecular Diels–Alder reaction, which opened the way for further investigations.
ED Sciences de la Vie et de la Santé
Design of protein-protein interaction stabilizers by directed evolution: application to synaptic interactions
by Manon DARRIBERE (Institut Interdisciplinaire de Neurosciences)
The defense will take place at 14h30 - Amphithéâtre Broca Bâtiment Broca, 146 rue Léo Saignat, 33000 Bordeaux
in front of the jury composed of
- Matthieu SAINLOS - Directeur de recherche - Université de Bordeaux - Directeur de these
- Agathe URVOAS - Professeure des universités - Université Paris-Saclay - I2BC Institute - Rapporteur
- Luc BRUNSVELD - Professeur - Eindhoven University of Technology - Rapporteur
- Françoise OCHSENBEIN - Directrice de recherche - Institut de Biologie Intégrative de la Cellule (I2BC) - Examinateur
- Arnaud GAUTHIER - Professeur - UMR 7203 Laboratoire des Biomolécules (LBM) - Examinateur
- Gilles GUICHARD - Directeur de recherche - Chimie et Biologie des Membranes et Nanoobjets (CBMN), UMR 5248/ Univ. Bordeaux / CNRS/ France - Examinateur
Protein–protein interactions (PPIs) are fundamental to cellular organization and molecular communication across virtually all biological systems. While extensive research has focused on inhibiting PPIs, comparatively few strategies exist for their stabilization. Yet, PPI stabilization represents a powerful approach, particularly valuable for targeting transient interactions and selectively modulating those mediated by hub domains. Despite promising examples involving small molecules, often derived from natural products, no systematic methodology currently exists for generating PPI stabilizers. To address this gap, we developed a strategy combining protein engineering and directed evolution to generate protein–protein interaction stabilizers. This approach consists of two phases: a first phase specifically aimed at identifying orthosteric candidates, followed by a second phase focused on improving their affinity. In the first phase, synthetic libraries derived from the tenth human fibronectin type III domain (10Fn3) are screened by phage display against an artificial fusion of the targeted PPI partners. Conducted under tailored experimental conditions, these selections allow isolation of orthosteric binders capable of recognizing the neo-surface formed by the interaction of the two partners. In the second phase, these candidates serve as templates for the creation of focused libraries via random mutagenesis. The resulting libraries are screened under adapted conditions to enrich variants with increased affinity and enhanced potential to stabilize the native complex. Selected candidates are subsequently characterized using biophysical, structural, and cellular fluorescence imaging methods to confirm their binding and stabilizing activity toward the target complex. We applied this strategy to PDZ domain interactions, particularly those of the scaffold protein PSD-95, which play a central role in synaptic signaling and organization. Using our directed evolution approach, we generated multiple selective stabilizers targeting PPIs mediated by PDZ domains of PSD-95. The successful development of these stabilizers demonstrates the robustness and versatility of our approach, providing valuable tools for fundamental research and a potential foundation for the future development of therapies targeting specific PPIs.
STUDY OF CUTANEOUS TELOCYTES IN INFANTILE HEMANGIOMA : CHARACTERIZATION, ANGIOGENIC PROPERTIES, AND THERAPEUTIC APPROACHES
by Léa PECHTIMALDJIAN (BoRdeaux Institute of onCology)
The defense will take place at 14h00 - Amphithéâtre BBS Bâtiment Bordeaux Biologie Santé 2 rue du Docteur Hoffmann Martinot 33000 Bordeaux
in front of the jury composed of
- Ulrich VALCOURT - Professeur des universités - Université Claude Bernard Lyon 1 (UCBL1) - Rapporteur
- Sabine BAILLY - Directrice de recherche - CEA - Rapporteur
- Olivia BOCCARA - Praticienne hospitalière - Hôpital Necker Paris - Examinateur
- Candice CHAPOULY - Chargée de recherche - Unité INSERM U1034 (Biologie des maladies cardiovasculaires) - Examinateur
- Bernhard WEHRLE-HALLER - Professeur - Department of Cell Physiology and Metabolism - Examinateur
Infantile hemangioma (IH) is the most common tumor in newborns. This benign vascular tumor, mainly affecting the skin, can quickly grow to a large size and cause functional or aesthetic complications. It is characterized by a proliferative phase followed by spontaneous involution, making it a unique model for studying the mechanisms of vascular regression. The standard treatment, propranolol, accelerates this regression, in particular by targeting a recently identified stromal population: telocytes (TC). These interstitial cells, which have been little studied until now, are characterized by long cytoplasmic extensions called telopodes and form a perivascular network. TC are present in many organs and are involved in tissue homeostasis and angiogenesis. The objective of this thesis was to characterize the evolution of the vascular network during IH regression and to evaluate the contribution of TC to this process. We first developed an innovative protocol for the tissue-clearing of human skin biopsies, enabling for the first time large-volume 3D imaging of their vascular architecture and cellular environment. Morphometric analysis showed that proliferative IH have long, tortuous, and voluminous vessels. During regression, we observed a process of vascular normalization involving the probable maturation of persistent vessels and the progressive pruning of immature structures, without massive apoptosis. At the same time, proliferative IH TC evolve from a spindle-shaped morphology, similar to that observed in healthy skin, to a unique dendritic morphology specific to the regression phase. This transition suggests a profound functional change. To evaluate their angiogenic role, we adapted the fibrin bead assay to incorporate TC derived from patients. Our results show that spindle-shaped TC have no significant effect on endothelial cell biology. In contrast, dendritic TC, derived from regressing IH, exert a paracrine anti-angiogenic effect by specifically blocking endothelial proliferation and sprouting. Screening analyses showed the secretion of growth factor traps, including pentraxin-3 (PTX3) that emerged as the main mediator. PTX3 binds FGF-2 and prevents the interaction with endothelial receptors, inhibiting proliferation, destabilizing VE-cadherin, and increasing endothelial motility, thereby facilitating vascular remodeling. TC also promote endothelial migration through mechanisms independent of PTX3, suggesting involvement in cell recycling in persistent vessels. These results stage TC as central regulators of vascular regression in IH via a paracrine anti-angiogenic program. Furthermore, our preliminary data suggest that propranolol promotes the acquisition of this protective phenotype by activating the TNFα/NF-κB pathway. Ongoing single-cell transcriptomic approaches aim to characterize the heterogeneity and plasticity of TC during this transition. Understanding how to induce this “normalizing” state of TC could open new therapeutic perspectives in oncology. Unlike current anti-angiogenic agents, which are often limited by adaptive resistance, we suggest that the cellular action of TC offers unprecedented potential for restoring angiogenic balance in solid tumors.
Potential of Chemically Modified Oligonucleotides to Overcome β-Lactam Resistance in Escherichia coli
by Lisa SCILLIA (Microbiologie fondamentale et Pathogénicité)
The defense will take place at 14h00 - Salle de conférence du CARF Centre d'Appui à la Recherche et à la Formation (CARF) site Carreire de l'Université de Bordeaux 146, rue Léo Saignat 33076 Bordeaux cedex
in front of the jury composed of
- Corinne ARPIN - Professeure des universités - Université de Bordeaux - Directeur de these
- Thierry NAAS - Maître de conférences - praticien hospitalier - Université Paris-Saclay Laboratoire IMVA-HB UMR1184 Hôpital Kremlin-Bicêtre, Le Kremlin-Bicêtre, France - Rapporteur
- Sophie SABLé - Maîtresse de conférences - Université de la Rochelle - Rapporteur
- Julien BUYCK - Maître de conférences - Université de Poitiers - Examinateur
- Olivier LAMBERT - Professeur des universités - Université de Bordeaux - Examinateur
- Tina KAUSS - Professeure des universités - Université de Bordeaux - CoDirecteur de these
Bacterial resistance to antibiotics is a major public health concern. The World Health Organization has established a list of priority pathogens for Research & Development of new antibiotics. This list classified extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae such as Escherichia coli resistant to third-generation cephalosporins (3GC) as critical priority targets. To combat antimicrobial resistance, one promising approach is to restore the efficacy of existing antibiotics. In this context, the use of antisense oligonucleotides (ASOs) represents an innovative strategy. The ARNA Laboratory has developed chemically modified ASOs targeting blaCTX-M-15 the most prevalent ESBL in E. coli. These chemical modifications aim to enhance ASO stability against nucleases and improve binding affinity to their target mRNA. To overcome the major obstacle of bacterial uptake, the ASOs were conjugated to a nucleolipid, generating LASOs (lipid–antisense oligonucleotides), a technology patented by the ARNA Laboratory. The goal of this interdisciplinary project, in collaboration with the MFP Laboratory, was to evaluate the effect of LASOs on reducing ceftriaxone (3GC) resistance in E. coli producing CTX-M-15. The objective of this PhD work was to elucidate the mode of action of LASOs. First, we confirmed that the phosphorothioate (PTO)-modified LASOα (5 µM) targeting blaCTX-M-15 mRNA was able to decrease the minimal inhibitory concentration (MIC) of ceftriaxone (MIC CFX) in several resistant E. coli strains, without affecting bacterial viability. The MIC CFX was reduced by up to 26-fold, although some variability was inherent to the experimental methodology. Transcriptional analyses by RT-qPCR showed no decrease in target mRNA levels, suggesting that LASOα PTO acts through steric hindrance rather than RNAse H-mediated cleavage. Translational analysis by Western blot revealed a 2-fold reduction in CTX-M-15 production in the presence of LASO. However, LASO handling posed significant technical challenges due to their amphiphilic properties, requiring extensive optimization of experimental conditions to obtain interpretable data. Further experiments and complementary techniques are needed to confirm these findings. Flow cytometry analyses indicated that nearly 1/3 bacterial cells interacted with LASOα PTO. Despite the use of several imaging approaches (confocal and high-resolution microscopy), it remains difficult to determine the precise intracellular localization of LASOs. Beyond their sequence-specific antisense activity, additional effects were explored. Preliminary experiments suggest that LASO may reduce the activity of purified β-lactamase on a chromogenic cephalosporin substrate. Finally, in vitro translation inhibition assays using alternative chemistries demonstrated that while LASOα PTO reduced translation by only 35%, other modifications achieved complete inhibition. These chemistries also produced significant reductions in MIC CFX (up to 32-fold with MOE gapmer PTO) in E. coli. These promising results pave the way for future therapeutic applications of LASOs in the fight against antimicrobial resistance.
beyond stomatal closure: mechanisms of water loss in leaves during severe drought and implication for plant survival
by Guillaume FORGET (Laboratoire de Biogenese Membranaire)
The defense will take place at 10h00 - Salle IBVM Centre INRAE 71 Avenue Edouard Bourlaux 33140 Villenave d'Ornon
in front of the jury composed of
- Jérôme JOUBES - Professeur des universités - Université de Bordeaux - Directeur de these
- Christine SCOFFONI - Associate Professor - California State University Los Angeles - Rapporteur
- Didier LE THIEC - Directeur de recherche - Université de Lorraine - Rapporteur
- Aude TIXIER - Chargée de recherche - Université Bourgogne Europe - Examinateur
- Sylvain DELZON - Directeur de recherche - Université de Bordeaux - CoDirecteur de these
Climate change is increasing the frequency and intensity of extreme weather events, exerting increasing pressure on vegetation. Among these, drought disrupts hydrological cycles and the plant hydraulic system, thereby compromising growth, productivity and even survival. Recent advances in plant hydraulics have revealed a close relationship between drought-induced mortality and xylem resistance to embolism. However, it remains difficult to predict the survival time of a plant subjected to prolonged drought that could lead to fatal hydraulic failure. Indeed, most studies have focused on the role of stomata in regulating water loss during drought, neglecting the residual water losses that persist after stomatal closure during prolonged and/or severe droughts. Yet, these water losses appear crucial for predicting survival, as they define the residual leaf conductance and the associated trait, the minimal leaf conductance. In this context, this thesis explores the mechanisms of residual water loss in leaves under severe drought in a crop, sunflower (Helianthus annuus), and a tree species, tulip poplar (Liriodendron tulipifera). Conducted along a gradient of water stress, this work is structured around three main axes and aimed at better understanding the determinants of minimal leaf conductance and their impact on plant survival : (i) analysis of stomatal leakiness, (ii) the significance of spatial stomatal coordination and its role in balancing transpiration and carbon assimilation, and (iii) the response of different cuticular layers. Using complementary and independent techniques, we demonstrated the occurrence of stomatal leakage from the onset of stomatal closure (corresponding to turgor loss) to high levels of water stress (ΨP50), which strongly influences residual leaf conductance and thus survival. Our results also highlight that the heterogeneous closure of stomata, referred to as stomatal patchiness, represents a drought response. In particular, between turgor loss (Ψtlp) and the onset of drought-induced photosynthetic decline (ΨP12), this spatial heterogeneity acts as a buffering mechanism that extends leaf physiological activity under water stress. Furthermore, by analysing this phenomenon across two temporal scales, we reveal a spatial hierarchy in patchiness, with small patches aggregating into larger ones revealing a spatial hierarchy that improves the leaf's response to environmental cues. In parallel with stomatal regulation, the cuticle also plays a key role in limiting water loss. Analysis of its different layers under water stress reveals that they do not have the same influence on limiting water loss during drought. While the amounts of cutin and waxes both increase with drought intensity, only cutin effectively contributes to reducing water loss, delaying the onset of hydraulic failure and, consequently, mortality. In conclusion, these results highlight the importance of both stomatal and cuticular mechanisms in regulating water loss during severe drought and their impact on plant survival. The combination of spatially heterogeneous stomatal responses and the differentiated contributions of cuticular layers illustrates how leaves attempt to conserve water. This coupling between stomatal and cuticular flexibility reflects an efficient adaptive strategy aimed at maintaining physiological functions while minimising water loss.
ED Sciences Physiques et de l'Ingénieur
Optimized and applied design of a tunable proton focusing and acceleration device for the PETAL laser
by Clément LACOSTE (Centre Lasers Intenses et Applications)
The defense will take place at 14h00 - A29 amphi B 351 Cr de la Libération, 33400 Talence Collège Sciences et Technologies - Université de Bordeaux
in front of the jury composed of
- Emmanuel D'HUMIERES - Professeur - Université de Bordeaux - Directeur de these
- Michèle RAYNAUD - Directrice de recherche - Laboratoire des Solides Irradiés (LSI), Rte de Saclay, 91120 Palaiseau - Rapporteur
- Brigitte CROS - Directrice de recherche - Laboratoire de physique des gaz et des plasmas - Rapporteur
- François LEGARE - Professeur - Institut National de la Recherche Scientifique, Centre Energie, Matériaux et Télécommunications - Examinateur
- Xavier DAVOINE - Ingénieur de recherche - Commissariat à l'Energie Atomique - Examinateur
- Patrizio ANTICI - Professeur - Institut National de la Recherche Scientifique, Centre Energie, Matériaux et Télécommunications - Directeur de these
The first Travelling Wave Tube (TWT) was conceived in 1947. The concept of TWT involves utilizing an incident electron beam to amplify the amplitude of an input electromagnetic field through coupling between the beam and a current propagating in a helix. The growing interest of this system takes source with the domain of high power and high frequency microwave devices such as the gyrotrons, the relativistic travelling wave tubes or the free-electron lasers. Applications of TWT include satellite communication systems, an electronic countermeasures or radar systems permitted by a wide instantaneous bandwidth, high gain and light weight. On the other hand, laser-driven ion acceleration is currently one of the most dynamic research domains due to its conpactness and numerous applications such as isochoric heating, isotope or neutron production, plasma radiography, and nuclear fusion in a fast ignition scheme. Among all laser ion acceleration mechanisms, Target Normal Sheath Acceleration (TNSA) is one of the most robust. It relies on the interaction of a high-intensity laser pulse with a solid target of micrometric thickness. The laser's pre-pulse creates a plasma on the target surface, and the main pulse accelerates electrons, generating a charge separation and a static electric field of several TV/m. This field accelerates protons—present on the target surface as hydrogenated impurities—to energies ranging from a few MeV to several tens of MeV. However, the angular divergence of TNSA acceleration, which remains relatively high (around $pm 20^circ$), and the exponential energy distribution of the protons with energy, limit its potential for applications. In this context, the idea of implementing a device coupled with TNSA has been proposed to post-accelerate and focus the proton beam. This concept, known as the helical coil, consists of guiding a discharge current, generated during the laser-plasma interaction, along a helical coil. The physics of current propagation in this coil is analogous to that of coupled transmission systems, such as traveling-wave tubes (TWTs). However, due to the broadband nature of the current pulse (with a spectral width corresponding to a duration of approximately 10~ps), dispersion along the coil becomes significant, which prevents efficient post-acceleration and focusing over the entire length of the helix, thereby limiting the range of potential applications. It is within this framework that the present manuscript is situated. The first part presents the analytical model developed during this thesis, aimed to understand the underlying physics and optimizing the geometry of the helical targets. The second part describes an experiment carried out on the ALLS laser facility, highlighting the impact of the helical targets on the spectra of protons and carbon ions. Finally, the third part is devoted to a numerical study of the application of helical targets to $alpha$-particles for the production of scandium radioisotopes intended for medical use.
mmW Full-Duplex transceiver with self-interference management and antenna
by Nicolas ROBIN (Laboratoire de l'Intégration du Matériau au Système)
The defense will take place at 9h00 - Amphithéâtre Jean-Paul DOM du laboratoire de l'IMS Bâtiment A31, 351 Cours de la Libération, 33405 Talence
in front of the jury composed of
- Anthony GHIOTTO - Maître de conférences - Bordeaux INP - Directeur de these
- Eric KERHERVé - Professeur des universités - Bordeaux INP - CoDirecteur de these
- Christian PERSON - Professeur des universités - IMT Atlantique - Rapporteur
- José Luis GONZALEZ JIMENEZ - Directeur de recherche - CEA-Leti - Rapporteur
- Dimitri LEDERER - Professeur des universités - Université Catholique de Louvain - Examinateur
- Jean-Baptiste BEGUERET - Professeur des universités - Université de Bordeaux - Examinateur
Unlicensed bands offer great opportunities for wireless communications, especially in the 60 GHz band which has stayed relatively free from mass-market applications. Low-power short-range point-to-point links, in particular, are a very attractive application because of the large available bandwidths and considerable atmospheric losses in this band. A system implementing in-band full-duplex in such context could yield data rates close to 10 Gbit/s, offering a great solution for contactless testing and connector-free board-to-board communications. In an in-band full-duplex communication, both terminals emit and receive signals simultaneously and operate in the same frequency band, which creates self-interferences between the transmitter and the receiver of a same terminal. Suppressing these self-interferences to allow proper demodulation of the signal of interest is a major challenge of such systems. The goal of this study is to build a solution with small footprint providing enough self-interference suppression to enable a low-power short-range in-band full-duplex link at 60 GHz. This work addresses various solutions to this problem, and especially the use of dual-polarized antenna architectures with high isolation between transmitter and receiver. Benefits and drawbacks of the antenna-on-chip and antenna-in-package technologies are assessed to determine which one is better suited for this challenge. The design of antennas-on-chip and antennas-in-package for in-band full-duplex communications is also discussed in this thesis. The layout of a PCB test board enabling measurements of a novel antenna-in-package concept is presented as well.
THz spectroscopy by photo-mixing of optical chirped pulses on photo-conductive antennas
by Gabriel TATON (Laboratoire de l'Intégration du Matériau au Système)
The defense will take place at 14h00 - Amphithéatre Jean-Paul DOM IMS - Laboratoire de l'Intégration du Matériau au Système, 351 Cours de la Libération, 33405 Talence Cedex, France
in front of the jury composed of
- Damien BIGOURD - Chargé de recherche - Université de Bordeaux - Directeur de these
- Jean-François ROUX - Professeur des universités - Université Savoie Mont-Blanc - Rapporteur
- Gaël MOURET - Professeur des universités - Université du Littoral Côte d'Opale - Rapporteur
- Emilien PEYTAVIT - Directeur de recherche - Université de Lille - Examinateur
- Patrick MOUNAIX - Directeur de recherche - Université de Bordeaux - CoDirecteur de these
Terahertz (THz) waves have been a major scientific interest over the past decades, opening new possibilities across many application fields for spectroscopy and non-destructive imaging. Nowadays, THz sources still provide limited emitted power. In particular, photoconductors exhibit good optical – THz conversion efficiency but saturate at low optical power. Moreover, their integration into array systems combining multiple THz sources is constrained because of the ultra-short nature of the optical pulses used for excitation, which implies high optical peak powers. The research presented here proposes a new method for the optical excitation of photo-conductors to address these limitations. The optical excitation process by photo-mixing, typically used in a continuous regime, is applied here with optical chirped pulses. This chirp enables control over the temporal distribution of instantaneous frequencies, and thus can adapt the optical beating that drives the photo-conductor. This beating determines the generated THz frequency and can therefore be shaped to target specific THz waveforms. The first configuration yields a quasi-continuous and quasi-monochromatic THz pulse, resembling the product of a continuous wave and a long temporal envelope. The second configuration also produces a long-duration THz pulse but with a broad spectrum. The latter is characterized by an instantaneous frequency distribution that can be compared to a THz chirp. The use of this excitation process should ultimately push the integration limits of photo-conductors towards higher THz emission powers.
ED Sociétés, Politique, Santé Publique
AUGMENTED REALITY AND MENTAL HEALTH EDUCATION: AN IMMERSIVE APPROACH TO REDUCING THE STIGMA OF SCHIZOPHRENIC DISORDERS AMONG STUDENTS
by Emma TISON (Laboratoire de Psychologie)
The defense will take place at 14h00 - Amphi E 3 ter Place de la Victoire, Bâtiment E, 33000 Bordeaux
in front of the jury composed of
- Antoinette PROUTEAU - Professeure - Université de Bordeaux - Directeur de these
- Frank LARøI - Professeur - University of Oslo, Department of Psychology - Rapporteur
- Marc MACé - Chargé de recherche - INRIA - Université Rennes 1 - Rapporteur
- Martin HACHET - Directeur de recherche - Centre Inria de l'Université de Bordeaux - CoDirecteur de these
- Camille SANREY - Maîtresse de conférences - Université de Strasbourg (UdS) Laboratoire de Psychologie des Cognitions (LPC) - Examinateur
- Bernard N'KAOUA - Professeur - Université de Bordeaux - Examinateur
Stigmatisation is one of the main determinants of schizophrenia, a mental disability (Yvon & Prouteau, 2017), and represents a global public health issue (WHO, 2013; Laforcade report, 2016). Mental health professionals are at the heart of this issue, particularly because they are the main source of stigmatisation reported by people with schizophrenia and their families (Schulze, 2007; for review, see Valéry and Prouteau, 2020). A recent study also shows that stigmatisation of psychiatric illnesses is already present among students (Caiada et al., 2024; Sideli et al., 2021). Improving the training of future professionals is therefore central to the issue of destigmatising mental health practices. It is in this context that the Live-It research project was developed, with the main objectives of i) enriching and complementing the training of health students and ii) destigmatising their representations of schizophrenia. To meet these objectives, four studies were conducted. A study of student needs was conducted to examine (i) health students' satisfaction with their current mental health training, (ii) the teaching methods they find most useful, and (iii) their interest in augmented reality as an additional method in this context and its conditions of application. The results reveal the application methods deemed relevant for an augmented reality tool in student training and their level of satisfaction with their current training. Subsequently, two other studies were conducted in parallel with the development of a schizophrenia simulation. The objectives of these studies were to pre-test the accuracy of the representation of schizophrenia symptoms in the simulation, the user experience, and the usefulness of the tool in terms of its training and destigmatisation objectives. Based on participant feedback, the simulation was finalised and an efficacy study was conducted. The aim of this study was to test the simulation's potential to destigmatise and its contribution to training. The results are discussed in this manuscript and highlight potential levers for reducing stigma in training. In conclusion, this doctoral thesis offers promising prospects for improving the training of health students on schizophrenia and destigmatising their perceptions. This work advocates for a scientific approach that is multidisciplinary, evidence-based and participatory.
Teaching on the Margins. Identity Construction and Professional Experiences in Rural Contemporary China
by Meng GAO (Laboratoire Cultures, Education, Sociétés)
The defense will take place at 9h00 - salle du conseil 3ter Pl. de la Victoire, 33000 Bordeaux
in front of the jury composed of
- Régis MALET - Professeur - laboratoire en sciences humaines et sociales, Université de Bordeaux - Directeur de these
- Sylvie CONDETTE - Professeure des universités - Université de Lille - Rapporteur
- Angela BARTHES - Professeure des universités - Laboratoire Population-Environnement-Développement, Université d'Aix-Marseille - Rapporteur
- Filippo PIRONE - Maître de conférences - Laboratoire Interdisciplinaire d'études du Politique Hannah Arendt, Université de Paris-Est Créteil - Examinateur
- Min LIU - Associate Professor - Institut de l'Éducation Internationale et Comparée, Université Normale de Beijing - Examinateur
- Mengqi ZHANG - Associate Professor - Institut de l'Éducation Comparée, l'Université Normale de la Capitale - Examinateur
This research is grounded in a social-constructivist perspective and seeks to understand how novice teachers in rural settings construct their professional identity during their first years of practice. The study is set in Linyi County, Shanxi Province, a context representative of China's rural educational realities. Its aim is to examine how these teachers interact with the territory—understood here as a social, cultural, and symbolic space—and how this interaction shapes both their professional adjustment and their understanding of the teaching profession. The research adopts a qualitative, autobiographical methodology, based on experience narratives collected from twenty teachers across eight rural schools. Through analysis of these narratives, the study highlights the processes of identity negotiation between the professional self and territoriality in teachers' identity construction. The territory functions as a structuring framework that carries specific values, norms, and constraints: the local economy, social relations, educational traditions, dialects, resource scarcity, and certain community attitudes (such as closedness or conservatism). These factors exert a tangible influence on how teachers conceive and live their work. However, the findings also show that identity construction is not merely a by-product of context. It depends strongly on each teacher's personal dispositions: their training trajectory, motivations, view of the profession, capacity for reflexivity, and willingness to adapt. The study thus brings to light the mutual and dynamic nature of the relationship between teachers and territory. While the rural environment shapes practices and representations, teachers in turn contribute to transforming territoriality through their choices, values, and actions. Professional identity therefore appears as the product of an ongoing dialogue between self and place, in which personal reflexivity plays a crucial role in the search for meaning and professional equilibrium.