ED Mathématiques et Informatique
Bioinformatics methods for the study of metabolism in glioblastoma
by Deisy Johanna GALVIS RODRIGUEZ (Institut de Biochimie et Génétique Cellulaires)
The defense will take place at 9h30 - Salle de conférence de l'IBGC 146 rue Léo Saignat, 33000 Bordeaux
in front of the jury composed of
- Macha NIKOLSKI - Directrice de recherche - Université de Bordeaux - Directeur de these
- Thomas DAUBON - Directeur de recherche - CNRS - CoDirecteur de these
- Fabien JOURDAN - Directeur de recherche - INRAE - Rapporteur
- Mohamed ELATI - Professeur des universités - Université de Lille - Rapporteur
- Florence CAVALLI - Chargée de recherche - Institut Curie - Examinateur
- Nicolas PAPADAKIS - Directeur de recherche - CNRS - Examinateur
Glioblastoma, the most aggressive form of brain cancer, remains incurable to date. Malignant cells thrive in a hypoxic and highly acidic tumor microenvironment, adapting through metabolic plasticity—leveraging alternative substrates, engaging in metabolic crosstalk among specialized subpopulations. Stable isotope-resolved metabolomics (SIRM), applied to glioblastoma spheroids, was complemented by transcriptomic profiling. However, bioinformatic tools tailored to SIRM datasets—especially those with complex, multifactorial designs—remain underdeveloped. Addressing this gap, the first part of this thesis introduced DIMet, a computational framework for differential analysis of isotopologue enrichment data. DIMet accounts for replicate-level variability, facilitating rigorous comparisons of metabolite labeling across experimental conditions. Its multi-omics extension further integrates transcriptomic and metabolomic data to elucidate the metabolic adaptations of glioblastoma cells. Spatial lipidome profiles, of xenografted glioblastoma brain tissues, revealed significant analytical challenges: high signal noise and isomerism. A critical need in spatial metabolomics was to expand mapping coverage. By leveraging cheminformatics resources and incorporating spatial/ion quality metrics, we successfully developed SpacePath, a novel method for pathway-level interpretation of spatial metabolomics data. Capable of handling ambiguous annotations, SpacePath uncovers both known and previously uncharacterized metabolic programs in situ. In conclusion, the bioinformatic methods developed in this thesis aim to uncover new mechanisms underlying this devastating disease.
Modeling and solving combinatorial optimization problems for reverse ecology
by Chabname GHASSEMI NEDJAD (LaBRI - Laboratoire Bordelais de Recherche en Informatique)
The defense will take place at 14h30 - Amphi LaBRI, Bâtiment A30 351 cours de la Libération 33400 Talence
in front of the jury composed of
- Cédric LHOUSSAINE - Professeur des universités - Université de Lille - Rapporteur
- Clémence FRIOUX - Chargée de recherche - Inria Bordeaux - CoDirecteur de these
- Jérémie BOURDON - Professeur des universités - Nantes Université - Rapporteur
- Meghyn BIENVENU - Directrice de recherche - CNRS - Examinateur
- Sophie COLOMBIE - Directrice de recherche - INRAE - Examinateur
- Clément FRAINAY - Chargé de recherche - INRAE - Examinateur
Determining the conditions for culturing microorganisms is a difficult and recurring problem in microbiology, as it requires identifying nutritional requirements and characterising metabolism. Genome-scale metabolic networks (GSMNs) obtained from genomic data enable simulations of the metabolic potential from a predefined environment. We developed methods that solve the inverse problem: predicting nutrient sources, or seeds, from a GSMN and a metabolic objective. The methods propose hybrid models, combining a discrete and iterative Boolean approximation of metabolic activity with numerical flux balance analysis (FBA). Applied at the scale of an individual population on GSMNs, the logic modelling method is a good approximation of flux balance constraints. The problem was then extended to communities of microorganisms. At this scale, it is necessary to consider possible transfers between networks, which increases the combinatorial complexity of the problem. We hypothesise that it is relevant to identify in priority minimal sets of nutrients that ensure the functionality of the metabolic network, which led us to consider prioritising optimisations on sets, first seeking to minimise seeds, then transfers. Three algorithms were developed, two of which ensure subset minimality. The application of methods to small communities of network reveals the combinatorial complexity, but also the complementarity of the algorithms.
ED Sciences Chimiques
Modelling Photoluminescence in Organic Systems: Exploring the impact of aggregation and mechanical effects on the molecular, electronic and optical properties
by Josianne OWONA (Institut des Sciences Moléculaires)
The defense will take place at 11h30 - Salon de Actos Universidad del Pais Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Facultad de Química, Paseo Manuel Lardizabal Pasealekua 3, 20018 Donostia - San Sebastián, Espagne
in front of the jury composed of
- Maria del Carmen RUIZ DELGADO - Professeure des universités - Université de Málaga - Rapporteur
- Luca GRISANTI - Chargé de recherche - CNR-IOM Trieste-SISSA - Rapporteur
- Martial BOGGIO-PASQUA - Directeur de recherche - Université de Toulouse III - Examinateur
- Elixabete REZABAL ASTIGARRAGA - Professeure des universités - Université du Pays Basque - Examinateur
- Lionel TRUFLANDIER - Maître de conférences - Université de Bordeaux - Examinateur
This thesis investigates the influence of molecular aggregation and mechanic effects on the photoluminescence of organic materials. Photoluminescence is initiated by photoexcitation that promotes an electron to an excited state followed by radiative relaxation. Its efficiency can be tuned by supramolecular arrangement or external stimuli. Aggregation can lead to electronic interaction between chromophores which affects orbital overlap and energy level splitting, enhancing or quenching emission depending on molecular disposition. Mechanical stress may perturb conformation, molecular packing, or charge distribution to induce radiative transitions. However, the structural and electronic origins of these effects remain only partially understood. Here, quantum chemical modeling is used to provide mechanistic insight, often experimentally inaccessible, into photophysical pathways, offering better prediction of optical behaviour. Density functional theory (DFT) and time-dependent (TD) DFT were applied throughout this thesis. First, we investigated aggregation effects on the phosphorescence properties in a carbazole dimer model. By systematically translating one molecule relative to the other along the molecular axes, we calculated the key parameters governing triplet state population and emission, ultimately identifying favourable molecular arrangements that promote phosphorescence efficiency. The established structure-property relationships provide design guidelines for improved organic phosphorescent materials. Second, we examined mechanoluminescence (ML) in pyridylvinylanthracene crystals under pressure. Using periodic DFT and TD-DFT within a hybrid QM/MM scheme to account for crystal environment effects, we characterized the structural changes and optical response associated with pressure of distinct polymorphs. The results reveal how intermolecular interactions and packing constraints influence ML and how pressure modifies the excited state character, notably imparting charge transfer (CT) character and increasing the excimer-like nature of the emissive state which cause a gradual redshift of the fluorescence. This leads to a new mechanistic picture behind the ML behaviour of organic crystals. Third, the effects of external pressure on the structural, linear, and nonlinear optical (NLO) properties of a push-pull molecular crystal were investigated. Upon exertion of isotropic pressure, we observed discontinuous changes in unit cell parameters, particularly along the stacking and CT directions, key torsion angles and packing geometries, which translate into abrupt shifts in excitation energies, exciton localization and CT character. Assuming the non-centrosymmetric co-facial arrangement adopted by the molecules are similar to that in thin films, the second harmonic response were also computed and proved highly sensitive to pressure, suggesting strategies to tune NLO properties in 2D materials. Finally, two joint experimental-theoretical studies explored photochromic systems with tailored emission properties. In diarylethene (DAE) derivatives, we confirmed aggregation-induced and anti-Kasha emission and demonstrated how the emission wavelength can be tuned by careful selection of substituents, leading to DAEs with potential for super-resolution imaging. In BODIPY derivatives, we analysed the combined effects of alkylation and boron substitution across different solvent polarities. We show that structural modifications enhance fluorescence, intersystem crossing, and singlet oxygen generation, thereby improving the performance as dual fluorescent photosensitizer. Overall, this thesis main objective is to establish structure-property relationships relating aggregation and mechanical stimuli to photoluminescence mechanisms in organic systems. By exploiting quantum mechanical methods as valuable tool, it provides insight into complex photophysical processes, while guiding the rational design for organic optoelectronic materials.
Inorganic-polymer composite materials at the positive electrode of Li-ion and all solid state batteries
by Ivone NUGRAHA (ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux)
The defense will take place at 13h30 - Amphithéâtre ICMCB – UMR5026 87, Avenue du Docteur Schweitzer 33608 PESSAC cedex (France)
in front of the jury composed of
- Laurence CROGUENNEC - Directrice de recherche - ICMCB Institut de Chimie de la Matière Condensée de Bordeaux – UMR5026 - Directeur de these
- Fannie ALLOIN - Directrice de recherche - LEPMI Laboratoire d'électrochimie et de physicochimie des matériaux et des interfaces - UMR 5279 - Rapporteur
- Didier GIGMES - Directeur de recherche - ICR Institut de Chimie Radicalaire – UMR 7273 - Rapporteur
- Eric CLOUTET - Directeur de recherche - LCPO Laboratoire de Chimie des Polymères Organiques - UMR 5629 - CoDirecteur de these
- Cyril AYMONIER - Directeur de recherche - ICMCB Institut de Chimie de la Matière Condensée de Bordeaux – UMR5026 - Examinateur
- Delphine FLAHAUT - Maîtresse de conférences - IPREM Institute of Analytical Sciences and Physico-Chemistry for Environment and Materials - UMR 5254 - Examinateur
- Marc DESCHAMPS - Docteur - Directeir pôle électrochimie - Blue Solutions - Examinateur
- Anthony BONNET - Docteur - Directeur scientifique matériaux pour l'énergie - Arkema - Examinateur
As the demand for high-power and high-energy-density batteries grows, all-solid-state batteries (ASSBs) have emerged as a promising concept. By replacing flammable liquid electrolytes with solid-state electrolytes and enabling lithium metal negative electrodes, ASSBs can achieve energy densities up to 400 Wh/kg. However, key challenges remain in the positive electrode, including interface stability, structural integrity, and the need for sufficient ionic and electronic conductivity. Thus, developing soft/polymeric materials that exhibit both electronic and ionic conductivity is a promising approach to addressing these issues. This thesis focuses on designing a mixed-conductive polymer that simultaneously acts as a conductive additive (electron conductor), a Li⁺ ion conductor, and a binder in the positive electrode. By integrating these functions into a single material, this approach aims to enhance the overall performance and durability of ASSBs. Preliminary investigations were conducted in conventional Li-ion batteries (LIBs) with liquid electrolytes to validate the material concept. Herein, a mixed-conductive polymer complex, Poly(3,4-ethylenedioxythiophene):poly [(4-styrenesulfonyl) (trifluoromethylsulfonyl) imide] (PEDOT:PSSTFSI), was proposed to replace conventional insulating poly(vinylidene fluoride) (PVDF) binders and carbon black (CB) in positive electrode formulations. PEDOT:PSSTFSI exhibits quite high electronic conductivity (30.8 ± 3.93 S/cm), surpassing the 7.3 ± 0.73 S/cm of PVDF:CB (1:1 wt.%), and significant ionic conductivity (3.4×10⁻⁵ S/cm at room temperature), promoting enhanced lithium-ion diffusion. In conventional LIBs with olivine-type active materials (LiFePO4 and LiFe0.4Mn0.6PO4), PEDOT:PSSTFSI electrodes demonstrated comparable specific capacities to PVDF:CB (1:1 wt.%) electrodes while substantially improving high-rate performance, particularly in formulations with high active material content (up to 94 wt.%). Cyclic voltammetry confirmed a one-order-of-magnitude higher Li⁺ diffusion coefficient of PEDOT:PSSTFSI electrodes, highlighting enhanced electrochemical kinetics. Additionally, XPS analysis further revealed thinner and more stable cathode–electrolyte interphase layers, indicating improved long-term cycling stability. In ASSBs configuration, PEDOT:PSSTFSI was successfully incorporated into Li3InCl6 solid electrolytes via a one-pot water-mediated synthesis. Its flexibility improved positive electrode pellet compactness and enhanced ionic-electronic conductivity, while enabling higher active material loading (up to 80 wt.%) with stable cyclability. PEDOT:PSSTFSI was shown not only to replace PVDF and CB in LIBs but also to enhance performance in ASSBs enabling higher active material content, faster charge/discharge capability, and superior cycling stability. These results establish PEDOT:PSSTFSI as a multifunctional electrode component that advances the development of next-generation high-performance ASSBs.
Biodegradable and dual-targeting polymersomes for site-specific drug delivery against Parkinson's Disease
by Sarah NIETO (Laboratoire de Chimie des Polymères Organiques)
The defense will take place at 9h30 - Amphithéâtre du CRPP 115 Avenue du Dr Albert Schweitzer, 33600 Pessac
in front of the jury composed of
- Sébastien LECOMMANDOUX - Full professor - Bordeaux INP - Directeur de these
- Hélène VAN DEN BERGUE - Associate Professor - Université de Montpellier, Institut des Biomolécules Max Mousseron - Rapporteur
- Nicolas TAPIS - Directeur de recherche - Université Paris-Saclay, Institut Galien - Rapporteur
- Jan VAN HEST - Full professor - Eindhoven University of Technology - Examinateur
- Sylvestre GRIZOT - Ingénieur de recherche - Medincell - Examinateur
- Guillaume FLEURY - Full professor - Université de Bordeaux, LCPO - Examinateur
- Angela MUTSCHLER - Assistant professor - Université de Bordeaux, LCPO - Examinateur
Brain disorders represent one of the most critical challenges in drug delivery, primarily because the blood-brain barrier (BBB) severely limits the transport of therapeutic agents into the central nervous system. Major advances in nanomedicine rely on the design of nanocarrier capable of encapsulating therapeutic payloads, crossing complex biological barriers and selectively delivering drugs to their target sites. Biodegradable polymersomes are promising innovative drug delivery systems owing to their loading capacity, surface functionalization potential and controlled delivery through membrane engineering. However, their formulation is frequently constrained by the inherent complexity of self-assembly, where the competition between thermodynamically favored structures and kinetically trapped states poses a major challenge to achieving homogeneous vesicle populations. This PhD thesis provides a framework for the rational experimental design and fabrication of nano-sized polymersomes composed of poly(ethylene glycol)-block-poly(D,L-lactide) (PEG-b-PDLLA) and poly(ethylene glycol)-block-poly(D,L-lactide-co-glycolide) (PEG-b-PLGA) block copolymers via a solvent-switch method. The degradation of PDLLA and PLGA, along with the acidification they generate, was assessed in relation to the loading of various hydrophilic cargoes during polymersome self-assembly and their subsequent degradation-induced cargo release. This nanoplatform offers a dual-therapeutic action aimed at restoring lysosomal function impaired in dopaminergic neurons in Parkinson's disease, by combining the controlled release of a neuroprotectant loaded within nano-sized polymersomes together with the acidification resulting from the block copolymers degradation. The polymersome design was further improved by implementing a dual-targeting strategy, functionalizing its surface with active ligands to promote BBB penetration and uptake in dopaminergic neurons for in vivo evaluation. In vitro studies demonstrated the therapeutic potential of this approach, highlighting a promising cutting-edge strategy for the treatment of Parkinson's disease.
ED Droit
Women from the perspective of fundamental rights
by Jeanne BARSALI (INSTITUT DE SCIENCES CRIMINELLES ET DE LA JUSTICE)
The defense will take place at 14h00 - 1K Université de Bordeaux, Pôle Juridique et Judiciaire, 35 place Pey Berland - CS 61751 - 33076 Bordeaux Cedex
in front of the jury composed of
- Charlotte CLAVERIE-ROUSSET - Professeur des universités - Université de Bordeaux - Directeur de these
- Ingrid MARIA - Professeur des universités - Université Grenoble Alpes - Rapporteur
- Paul CAZALBOU - Professeur des universités - Université Toulouse 1 Capitole - Rapporteur
- Jérôme PORTA - Professeur des universités - Université de Bordeaux - Examinateur
By their universality, fundamental rights aim to protect the most essential values of any individual. However, their efficiency presupposes respect of the principle of equality, which is not only limited to an uniform treatment : it implies different situations call for different treatments, in order to ensure real equality. Fundamental rights, by their universality, aim to protect the most essential values of every individual. Their effectiveness presupposes, however, respect for the principle of equality, which is not limited to uniform treatment: it implies that different situations call for differential treatment, in order to ensure real equality. However, women, because of their own biological and social specificities, often find themselves in special situations that justify increased protection. Yet women often end up, because of their own biological and social specificities, in special situations that justify an increased protection. This specificity leads to a distinction between two forms of protection. The first one, which is explicit, consists in providing devices designed directly for women in situations that only concern them, such as pregnancy or motherhood. The second one is implicit and acts through general rules applicable to all, but of which women end up being the main beneficiaries because of their particular exposure to certain social phenomena such as domestic violence, where women represent the vast majority of victims. Nevertheless the articulation of these two forms of protection reveals structural insufficiencies. Although numerous, the texts come up against an incomplete application and this leaves a significant gap between the proclamation of rights and their concrete effectiveness. On top of that, certain issues specific to women remain insufficiently supervised or ignored by the legislator, which maintains persistent discrimination in essential areas such as the economy or health. The analysis thus highlights the need for a two-fold approach : on one hand, strengthening the application and effectiveness of existing schemes in order to ensure their full effectiveness, and on the other hand, considering new ways for improvement to fill the current gaps and ensure a more complete and equitable protection of women's fundamental rights.
The transformations of labour through the lens of platformization
by Kieran VAN DEN BERGH (COMPTRASEC - Centre de Droit Comparé de Travail et de la Sécurité Sociale)
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
- Isabelle DAUGAREILH - Directeur de recherche émérite - Université de Bordeaux - Directeur de these
- Alexandre FABRE - Professeur agrégé - Paris 1 Panthéon Sorbonne - Rapporteur
- Stéphane VERNAC - Professeur agrégé - Université de Picardie - Jules Verne - Rapporteur
- Simon DEAKIN - Professeur - Université de Cambridge - Examinateur
- Gilles AUZERO - Professeur agrégé - Université de Bordeaux - Examinateur
- Emmanuelle MAZUYER - Directrice de recherche - Université Lyon 2 - Examinateur
The platformization of labour is one of the major transformations in the contemporary world of work. Platform operators, relying on connected digital systems, have developed organizational models that fundamentally reshape the way power is expressed. The thesis examines the changes that platformization imposes on work and workers, and the way in which French law has answered to those changes. The French legislature has created a set of rules that proclaim the independence of platform workers while granting them certain social guarantees. However, the thesis shows that most lack the material and legal means for genuine independence. A distinction separating true entrepreneurs, who possess these means, from fictitious entrepreneurs, formally independent but materially subordinated, becomes necessary. By inserting a third status into the Labor Code to accommodate "false independents," the legislature enables a new form of sub-employment, excluded from common labour law protections, which threatens the integrity of labour law. The thesis builds two central concepts. "Digital subordination" first identifies the ways in which power is expressed and how it is intensified. Operators express their authority through the technical structure of their digital systems, which channel, monitor, and sanction behaviors. This subordination operates over a mass of anonymous and interchangeable workers, creating a form of collective constraint that dissolves the individual within a system of algorithmic management. "Professional neutrality" then constitutes a central classification criterion. It distinguishes between two categories of operators: those who provide a matching service and allow workers to develop both an independent activity and their own clientele, on the one hand. And, on the other hand, those who use their platforms to integrate a workforce into their business by imposing rates and standards, evaluating workers, and sanctioning deviant behaviors. Both use "electronic matching platforms", but the former remains professionally neutral by serving the worker, while the latter integrates the worker into its service. The thesis defends an orthodox approach to labour law: only genuinely independent workers may be excluded from the scope of its protections. The set of rules created for independent platform workers should apply only to this category. Workers subject to digital subordination should, on the other hand, fall under employment status. This is why the thesis advocates for a special employment contract, adapted to the specificities of platform labour. Examining the phenomenon of work platformization through a legal lens ultimately reveals an even more fundamental challenge: the digitization of work enables the extraction of dual surplus value. To the classical exploitation of labour power is added an entirely unprecedented form of digital exploitation. By capturing the digital representation of each service performed, operators accumulate data that can feed artificial intelligence systems that learn from human work in order to replace it. Workers thus unknowingly train the systems that will render them obsolete. This digital absorption confronts labour law with its limits and justifies the thesis's opening of new perspectives. The thesis concludes that human labour is not a commodity and that the market cannot obtain the benefit of subordinated labour without offering the protections that this condition demands. Faced with platformization, which reduces work to a liquid and consumable good, labour law must adapt its tools without abandoning its principles if it hopes to preserve the human condition at work.
ED Sciences de la Vie et de la Santé
Effects of fifth generation (5G) environmental radio frequency signals on oxidative stress and DNA repair in skin cells.
by Jana HAIDAR (Laboratoire de l'Intégration du Matériau au Système)
The defense will take place at 9h00 - Amphi J.P.DOM A0.85 IMS laboratory / UMR 5218 Bordeaux University - Batiment A31 351 av de la libération 33400 Talence
in front of the jury composed of
- Yann PERCHERANCIER - Directeur de recherche - Université de Bordeaux - Directeur de these
- Yvan CANITROT - Directeur de recherche - Université de Toulouse , UMR 5077 - MCD - Molecular, Cellular and Developmental Biology Unit Equipe : Chromatin and Cell Proliferation - Examinateur
- Oceane MARTIN - Associate Professor - Université de Bordeaux - Institut de Biochimie et Génétique Cellulaires - Examinateur
- Nicolas FORAY - Directeur de recherche - Unité INSERM UMR 1296 - Rapporteur
- Marie-Pierre ROLS - Directrice de recherche - Université de Toulouse - Rapporteur
Bioelectromagnetics investigates how electromagnetic fields (EMFs) interact with biological systems and affect their function. While the thermal effects of radiofrequency (RF) fields—such as tissue heating—are well established and form the basis of current safety standards, non-thermal effects at low exposure levels remain poorly understood, with inconsistent findings in the literature. With the widespread deployment of wireless technologies, human exposure to RF-EMFs has increased significantly, raising concerns about possible impacts on cellular stress responses, particularly oxidative stress and DNA damage. This doctoral research investigated whether 5G-modulated RF-EMFs at 3.5 GHz, applied at environmentally relevant specific absorption rates (SARs) of 0.08 and 4 W/kg, could induce oxidative stress or interfere with DNA repair in human skin cells in vitro. Bioluminescence Resonance Energy Transfer (BRET) probes were specifically developed to characterize the KEAP1–NRF2 (Kelch-like ECH-associated protein 1–nuclear factor (erythroid-derived 2)-like 2) antioxidant pathway and the DDB1 (damage-specific DNA-binding protein 1) / DDB2 (damage-specific DNA-binding protein 2) DNA damage recognition complex, with the aim of providing reference readouts for oxidative stress and DNA repair, respectively. However, despite successful design and initial validation, the developed probes did not perform with sufficient reproducibility, and therefore they were not employed in the subsequent experiments involving RF-EMF exposure. As an alternative strategy, we employed the established ROBINy BRET redox biosensors, targeted to either the cytosol or the mitochondria, to enable real-time monitoring of reactive oxygen species (ROS) dynamics over a 24-hour period. These assays were conducted both under RF exposure alone and in combination with well-characterized ROS inducers (H₂O₂, KP372-1, and antimycin A). We also quantified cyclobutane pyrimidine dimers (CPDs)—a hallmark of UVB-induced DNA damage—up to 48 hours after combined exposure to 5G RF-EMFs and UVB irradiation (20 mJ/cm²), in order to assess a potential impact on the nucleotide excision repair (NER) pathway. Under rigorously controlled conditions, with validated dosimetry and constant temperature, 5G-modulated RF-EMFs at 3.5 GHz did not induce oxidative stress in XP6BE immortalized fibroblasts. They also failed to increase ROS production in the presence of established ROS inducers, whether through direct effects or adaptive responses. Similarly, no interaction was observed between 5G exposure and UVB irradiation on DNA damage repair via the nucleotide excision repair (NER) pathway in HaCaT keratinocytes. Altogether, these results provide strong evidence that, within the tested framework, 5G RF-EMF exposure does not alter oxidative balance or DNA repair, and they contribute valuable data to the evidence-based evaluation of potential health risks associated with 5G technologies
BIODYNAMIC PREPARATIONS IN VITICULTURE: Professional perceptions and analysis of their effects on vine and grape berry development.
by Manuela BRANDO PRADILLA (Oenologie)
The defense will take place at 14h00 - Amphithéâtre Institut des sciences de la vigne et du vin 210 Chemin de Leysotte, 33140 Villenave-d'Ornon
in front of the jury composed of
- Laurence GENY - Professeure des universités - Université de Bordeaux - Directeur de these
- Markus RIENTH - Professeur des universités - Université de Changins - Rapporteur
- Chantal MAURY - Professeure des universités - Ecole Supérieure des Agricultures (ESA) Angers - Rapporteur
- Jordi BALLESTER - Maître de conférences - Université de Bourgogne - Examinateur
- Gilles DE REVEL - Professeur des universités - Université de Bordeaux - Examinateur
Biodynamic agriculture, founded by Rudolf Steiner in 1924, originated from a series of lectures addressing the challenges of crop yield and health issues on farms due to the increasing use of chemical inputs. Steiner conceptualised the farm as a living organism, where every element — including soils, plants, and the surrounding environment — interacts in a synergistic manner. He advocated for organic and mineral preparations, such as preparation P500 (horn manure) and preparation P501 (horn silica) to support soil and plant health. This approach has notably influenced organic agriculture and aligns with agroecology principles aimed at promoting sustainable farming systems. Although biodynamics is viewed by some as esoteric or pseudoscientific, it is gradually gaining recognition in the agricultural landscape: a growing number of farms are adopting these practices, and vintners are questioning the integration of these methods into their production. This study aims (i)to deepen the understanding of the wine industry's perspective on biodynamics through a textual analysis of its representations, (ii) to identify the metabolic processes influenced by biodynamic preparations using various methods, including field measurements, biochemical analyses, and microscopic techniques, and (iii) to gather factual elements to improve practices, particularly in the Bordeaux vineyard. The textual analysis of representations reveals four perceptions within the sector, ranging from curiosity to scepticism, and highlights the importance of respecting individual perspectives and fostering exchanges between winemakers to establish constructive dialogue. The application of biodynamic preparations demonstrates variable effects depending on the parameters studied. While there is no significant influence on phenology, vigor, or vegetative expression, growth appears to be slowed, likely due to differences in water regulation. Vines cultivated biodynamically also show increased resistance to pathogens, attributed to the stimulation of specific defense metabolites. Potential fertility is enhanced, evidenced by an increase in inflorescence primordia and flowers. However, after bud break, both floral induction and initiation are tightly regulated. Although berries and clusters tend to be smaller and lighter, which may reduce yield, this reduction does not exceed 10%. For the first time, this study examines the impact of biodynamic preparations on the maturation of grape skins. Modified hormonal regulation and inhibition of skin degradation enzymes result in less degradable cell walls and thicker skins, slowing down mesocarp growth and reducing berry sensitivity to pathogens. These effects lead to reduced extractability of phenolic compounds in the biodynamic wine.
ED Sciences Physiques et de l'Ingénieur
Origin and properties of free-floating planets
by Tommy RODRIGUES (Laboratoire d'Astrophysique de Bordeaux)
The defense will take place at 14h00 - Salle Univers Laboratoire d'Astrophysique de Bordeaux Université de Bordeaux - Bât B18N, allée Geoffroy Saint-Hilaire CS 50023, 33615 Pessac Cedex, France
in front of the jury composed of
- Hervé BOUY - Professeur des universités - Université de Bordeaux - Directeur de these
- Estelle MORAUX - Professeure - Université Grenoble Alpes - Rapporteur
- Jean-Louis MONIN - Professeur émérite - Université Grenoble Alpes - Rapporteur
- Sylvain BONTEMPS - Directeur de recherche - Université de Bordeaux - Examinateur
- Timea CSENGERI - Chargée de recherche - Université de Bordeaux - Examinateur
- Gaspard DUCHENE - Astronome adjoint - Université Grenoble Alpes - Examinateur
Free-floating planets (FFPs) are planetary-mass objects that do not orbit a star, but roam the galaxy isolated. With masses below the deuterium-fusion limit (<13 Jupiter masses, MJup), FFPs cannot sustain any nuclear fusion and thus continuously cool and fade over time, becoming intrinsically faint and challenging to detect. However, during their first few million years, they remain sufficiently hot and bright in the infrared to be directly detectable in nearby, young star forming regions. FFPs may form either as massive planets ejected from protoplanetary disks through dynamical interactions, or as the lowest-mass products of star-like formation processes, from the collapse of tiny molecular clumps or from halted gas accretion onto a protostellar core. However, the relative contribution of each mechanism remains unknown. A major key observational diagnostic to test FFP formation theories is through the occurrence and properties of circumstellar disks, as different formation mechanisms predict distinct disk fractions and properties. This thesis presents a statistical study of the presence of disks surrounding low-mass members of the nearby (145 pc), young (5–10 Myr) Upper Scorpius association, which hosts a recently identified rich population of dozens of FFPs. To identify the presence of disks through the excess emission they produce at infrared (IR) wavelengths, a first model-based approach involving spectral energy distribution fitting was employed, which revealed the limitations of current models for the purpose of identifying IR excesses in planetary-mass objects, likely due to incomplete treatment of cloud formation at low temperatures. This motivated the development of an empirical, color-based method combined with Bayesian outlier detection, leveraging unWISE mid-IR photometry to robustly model the diskless photospheric sequence and identify sources exhibiting IR excesses in the (W1–W2) color. This approach enabled the derivation of robust disk fractions down to 6–8 MJup, depending on the assumed age, substantially extending previous studies into the planetary-mass regime and including 17–40 FFPs, representing the most comprehensive sample to date. The results revealed a continuous increase in disk fraction toward lower masses, exceeding 30%, with a possible flattening below 25–45 MJup that may indicate a transition in dominant formation processes. This change of trend, however, should be considered with caution and requires confirmation. In parallel, 1.3 mm continuum observations were conducted with the NOEMA interferometer, targeting six FFPs exhibiting IR excesses in the young, nearby Taurus star-forming region. One source was detected, with a flux translated into a dust mass of 0.169–0.657 Earth masses, ranking among the least massive disks ever observed and doubling the number of confirmed millimeter detections of disks around FFPs. The inferred disk mass follows the extrapolated Mdust-Mstar relation down to planetary masses, suggesting a continuity with stellar and substellar populations and favoring formation via core collapse rather than ejection from a planetary system, which would have stripped the disk of material. In conclusion, this work places new constraints on the disk fraction down to the planetary-mass regime through a fully reproducible IR excess detection procedure, and sets the stage for extending the analysis to other populations. It also reports only the second millimeter detection of a FFP disk, highlighting the urgent need to increase the number of detection and populate the lower end of the disk mass distribution.
Hydrodynamic instabilities in binary fluids with miscibility gap.
by Anubhav DUBEY (I2M - Institut de Mécanique et d'Ingénierie de Bordeaux)
The defense will take place at 10h00 - Amphi 1 Amphi 1 Batiment A9
in front of the jury composed of
- Sakir AMIROUDINE - Professeur - I2M, Université de Bordeaux - Directeur de these
- Omar MATAR - Professor - Department of Chemical Engineering, Imperial College London - Rapporteur
- Christian RUYER-QUIL - Professeur - LOCIE, Université Savoie Mont Blanc - Rapporteur
- Rama GOVINDARAJAN - Professeure - ICTS-TIFR - Examinateur
- Marie-Charlotte RENOULT - Associate Professor - CORIA, INSA Rouen Normandie - Examinateur
- Patrice LE GAL - Directeur de recherche - IRPHE, Aix Marseille Université - Examinateur
- Jean-Pierre DELVILLE - Directeur de recherche - LOMA, University of Bordeaux - Examinateur
Two fluids can form an immiscible pair, a miscible pair, or a pair that exhibits partial miscibility depending on an external stimulus. A critical value of this stimulus governs the process of mixing or phase-segregation. The external stimulus can be in the form of the temperature, concentration or the pH of the system. A thorough investigation of the response of the fluid pair to such stimulus is necessary to understand the fundamental flow behavior and efficient utilization in various applications such as targeted-drug delivery, liquid-liquid mass transfer, flow pattern tuning to name a few. Among the different kinds of stimuli, the current thesis specifically focuses on binary fluids exhibiting temperature sensitive miscibility gap. In line with a broader perspective of elucidating fundamental flow features, three different hydrodynamic instabilities namely - Rayleigh-Taylor (RT) instability, Kelvin-Helmholtz (KH) instability and Rayleigh-Bénard-Marangoni (RBM) instability have been investigated. To this end, a novel phase-field approach that incorporates a tunable miscibility framework is proposed. In context of binary fluids with miscibility gap, a change in degree of miscibility affects the thermophysical properties in the bulk regions as well as the surface tension associated with the interface which underpins the two-phase hydrodynamic instabilities. The RT instability is the evolution of a perturbed interface between two superposed fluids subjected to an external acceleration directed from the heavier fluid to the lighter fluid. The spatio-temporal evolution of the perturbation is governed by competition between the buoyancy forces and the surface tension force. In the current work, we first employ linear stability analysis to derive a miscibility dependent dispersion relation. A parametric analysis of the dispersion relation reveals three qualitatively distinct growth pattern for the temporal evolution of the perturbation. Subsequently, non-linear numerical simulations are performed to corroborate the findings from the linear analysis. Further, the late-time analysis reveals that the emanation of secondary instability in form of Kelvin-Helmholtz rolls is a function of the degree of partial miscibility. The KH instability arises due to shearing at the interface between the two fluids. The numerical analysis entails two different configurations based on the thermodynamic state of the system. In first configuration, the fluid pair is assumed to be at thermodynamic equilibrium at a temperature lower than the consolute temperature to investigate the effect of the effective surface tension, the degree of stratification and the shear flow profile. In the second configuration, the fluid pair is initialized at an initially immiscible/partially miscible state and is driven towards a completely miscible state. The results reveal the competition between the advection induced sharpening of the interface and the diffusion induced broadening of the interface as a function of the initial surface tension of the fluid pair. The RBM instability is the onset of free convection in a fluid, placed in an external acceleration field, due to the inhomogeneities ascribed to the presence of temperature or concentration gradient. In this work, we consider the thermally induced convection in a specific binary fluid pair - FC72-1cSt silicone oil. A linear stability analysis is performed employing the Chebyshev pseudo-spectral method to reveal the critical Rayleigh number as a function of the height ratios of the fluid layers and the degree of partial miscibility. The effect of the strength of the Marangoni flow is analyzed parametrically. The results reveal a monotonic decrease in the propensity of the system to exhibit oscillatory convection as the fluid pair approaches the consolute temperature. Subsequently, the eigen values are obtained to find the maximum oscillation frequency and therefore the minimum time period of oscillation.
ED Sciences et environnements
Modelling past and future evolution of sandy coasts
by Mohammad TRABOULSI (Environnements et Paléoenvironnements Océaniques et Continentaux)
The defense will take place at 14h00 - Amphithéâtre PABA, Bâtiment B5 Allée Geoffroy Saint-Hilaire, CS 50023, 33615 Pessac
in front of the jury composed of
- Bruno CASTELLE - Directeur de recherche - Université de Bordeaux - Directeur de these
- Déborah IDIER - Directrice de recherche - BRGM - CoDirecteur de these
- Angélique MELET - Chargée de recherche - LEGOS – CNES/CNRS/IRD/Université de Toulouse - Examinateur
- Alexandra TOIMIL - Ingénieure de recherche - Universidad de Cantabria - Examinateur
- Nadia SÉNÉCHAL - Professeure des universités - EPOC – UMR5805, CNRS–Université de Bordeaux - Examinateur
- Albert FALQUÉS - Professeur des universités - Universitat Politècnica de Catalunya (UPC) - Rapporteur
- Julien CHAUCHAT - Directeur de recherche - Laboratoire des Écoulements Géophysiques et Industriels (LEGI – UMR5519), Univ.GrenobleAlpes / CNRS / GrenobleINP. - Rapporteur
This thesis develops LX-ST, a reduced-complexity framework for simulating medium- to long-term shoreline evolution under sea-level rise (SLR). LX-ST couples ShoreTrans, which computes cross-shore profile translation under SLR, with LX-Shore, which resolves alongshore sediment transport and shoreline planform change. By linking cross-shore adjustment with alongshore gradients, the framework enables efficient 3D morphodynamic simulations while preserving the key feedbacks that govern sandy coast evolution at decadal to centennial scales. Short-term storm effects are treated as high-frequency variability superimposed on slower trends.The approach is first benchmarked with synthetic cases spanning free coasts and coasts influenced by structures, showing consistent rollover, encroachment, and trajectory-shift behaviors across coupling strategies. It is then applied to a 5-km beach–dune system at Lacanau, southwest France, fronted by a long seawall. Using site topobathymetry and regional wave forcing, LX-ST reproduces observed decadal retreat patterns and spatial contrasts updrift and downdrift of the structure, indicating skill at the intended scale of application.Building on this setup, the thesis conducts a global sensitivity analysis for Lacanau under three sea-level scenarios (SSP2-4.5, SSP5-8.5, High-End). First-order Sobol indices quantify how uncertainties in inputs propagate to shoreline projections. The analysis shows that the SLR trajectory and the background erosion rate are the dominant contributors to variance. Interactions mediated by shoreline orientation, evolving depth of closure, and structure-induced transport gradients produce non-linear responses and spatially heterogeneous envelopes of change. Across scenarios, retreat magnitudes are of order O(10² m) by 2100, with local amplification where accommodation space is limited and sediment supply is constrained. LX-ST is not positioned as an operational forecasting tool. Its value is to provide a transparent, computationally tractable platform for exploring scenario space, identifying the drivers that matter most, and revealing when and where morphodynamic feedbacks can shift coastal trajectories. The framework supports risk-informed adaptation by clarifying uncertainty structure and spatial patterns of change while remaining compatible with site data and management constraints.
Evolution of plasticity in life-history traits of Hymenoscyphus fraxineus, an expanding forest pathogen
by Clémence BECANS (BIOGECO - BIOdiversité, Gènes & Communautés)
The defense will take place at h00 - Airial 69 route d'Arcachon, bâtiment Airial, 33610 Cestas
in front of the jury composed of
- Jean-Paul SOULARUE - Ingénieur - INRAE - Directeur de these
- Anne-Sophie WALKER - Ingénieure de recherche - INRAE - Rapporteur
- Pascal FREY - Directeur de recherche - INRAE - Rapporteur
- Cécile ROBIN - Directrice de recherche - INRAE - CoDirecteur de these
- Chloé DELMAS - Directrice de recherche - INRAE - Examinateur
- Mathieu LAPARIE - Chargé de recherche - INRAE - Examinateur
Thirty years after its emergence in Northern Europe, ash dieback continues to spread across the continent, destabilizing ecosystems dominated by common ash (Fraxinus excelsior). This disease is caused by Hymenoscyphus fraxineus, a sexually reproducing ascomycete fungal pathogen. Despite undergoing a strong genetic bottleneck during its introduction from Manchuria, the fungus has successfully established itself in highly diverse environments. Phenotypic plasticity refers to the variation in the expression of a given trait under changing environmental conditions. We tested the hypothesis that the spread of ash dieback is associated with the evolution of plasticity in adaptive traits of H. fraxineus. Using a synchronic approach, we sampled infected ash rachises from five sites along a north–south latitudinal gradient (Lithuania, Denmark, Switzerland, France, and Italy), thereby establishing five populations of H. fraxineus isolates. These populations have contrasting epidemiological histories and are exposed to different climatic conditions and ash species. A first series of in vitro experiments was conducted to assess the plasticity of mycelial growth and survival under varying humidity and temperature. No difference in the plasticity of mycelial growth in response to humidity was observed among the studied populations, nor any difference in growth or survival at low (3 °C, 6 °C) or moderate (22 °C) temperatures. However, isolates from the Italian population, the southernmost of our sampling sites, showed markedly higher growth at elevated temperature (26 °C) than isolates from other populations. Conversely, the mycelial viability of Lithuanian isolates decreased more rapidly at high temperatures (> 30 °C) than that of isolates from the other populations. Isolates from the Lithuanian and Italian populations were inoculated onto ash petioles of young Fraxinus seedlings. No difference in aggressiveness was observed on F. excelsior at 22 °C between the two populations. However, aggressiveness, assessed using three different criteria, was overall less plastic in Italian isolates in response to temperature (22 °C vs. 26 °C) and host species (F. excelsior vs. F. ornus, the latter occurring only in southern Europe and showing greater resistance to ash dieback) than in Lithuanian isolates. No difference in stem aggressiveness was detected between the two populations at 22 °C on F. excelsior. The third part of this thesis focuses on the relationship between the fruiting phenology of H. fraxineus and temperature conditions. In this context, infected ash rachises were collected from northern France, southern France, and Italy. After 12 weeks of incubation at 22 °C and 26 °C, the Italian population of H. fraxineus exhibited an earlier fruiting phenology than the French populations at both temperatures. Overall, our results suggest an adaptation of H. fraxineus to the biotic and abiotic conditions of southern Europe and highlight the potential threat that the pathogen represents in this region, even though its spread and the severity of ash dieback were previously considered limited there. More broadly, our findings emphasize the need to integrate the evolution of phenotypic plasticity in pathogens into predictive models of epidemic risk in forest ecosystems.
ED Sociétés, Politique, Santé Publique
Educational Policies and Islamic Education in Senegal: An Analysis of the Modernization of Daara and the Institutionalization of Franco-Arab Schools.
by Mouhamed GUEYE (Laboratoire Cultures, Education, Sociétés)
The defense will take place at 14h00 - Salle des thèses 3ter Place de la Victoire, 33000 Bordeaux
in front of the jury composed of
- Jean-François BRUNEAUD - Professeur - Université de Bordeaux - Directeur de these
- Sarah CROCHE - Professeure - Université de Picardie - Rapporteur
- Mahamet TIMERA - Professeur - Université Paris Diderot Paris 7 (UFR Sciences sociales) - Rapporteur
- Mamadou bouna TIMERA - Professeur - Université Cheikh Anta Diop Dakar (UCAD) - Examinateur
This research, entitled Educational Policies and Islamic Education in Senegal: An Analysis of the Modernization of Daara and the Institutionalization of Franco-Arab Schools, examines the dynamics shaping Islamic education in a context of educational reforms. Since the 2000s, the Senegalese state, supported by its technical and financial partners, has implemented policies aimed at modernizing the daara (Qur'anic schools) notably through the Basic Education Quality and Equity Improvement Program (PAQEEB) and integrating Franco-Arab schools into the public education system. These reforms have produced mixed results and revealed deep structural and political tensions. The central research question explores how the political, economic, educational, religious, and international stakes tied to these reforms affect state autonomy and reshape Islamic education. Two decades after their launch, these policies remain incomplete, while significantly transforming the Islamic educational landscape. The study pursues two main objectives: to analyze the political and economic autonomy of the state in the face of local and international pressures; and to examine the internal recompositions of Islamic education, particularly the trajectories of daara and Franco-Arab schools. The theoretical framework draws on three key concepts: modernization, institutionalization, and stakes to understand these reforms as multidimensional processes in which state logics, international influences, and local resistances converge. Methodologically, the research relies on triangulation: semi-structured interviews with institutional, educational, and religious actors; field observations; and documentary analysis of official texts and educational projects. The findings first highlight the limits of the state in implementing reforms. While PAQEEB introduced a degree of flexibility, its effectiveness remains undermined by financial dependence, insufficient infrastructure, and the persistent mistrust of Qur'anic teachers. Furthermore, the state tends to favor Franco-Arab schools more easily integrated into the national systemat the expense of traditional daara. This implicit choice paradoxically reinforces the autonomy of religious actors, in a context strongly marked by the influence of Sufi brotherhoods, particularly the Mouride community. The research also brings to light a process of “bottom-up” modernization, driven by Qur'anic masters and private initiatives responding to growing social demand for hybrid education. These modernized daara, increasingly attended by middle-class families and the diaspora, offer more attractive conditions but simultaneously accentuate socio-economic divides and reinforce the partial privatization of Islamic education, beyond the state's control. Ultimately, the reforms emerge not as purely technical programs but as political processes traversed by competing logics of power and legitimacy. Caught between international pressures and local resistances, the state struggles to reconcile modernization with cultural rootedness. By focusing on PAQEEBa program still little explored in the literature this study provides an original contribution to the understanding of ongoing transformations and sheds light on the tensions between educational sovereignty, international influences, and the reconfiguration of religious and educational actors in West Africa.
Study of the professional gestures of teachers with pupils with difficulties in mathematics in priority education
by Anaïs HATU (Laboratoire d'épistémologie et didactiques disciplinaires, professionnelle et comparée de Bordeaux)
The defense will take place at 14h30 - E302 INSPE de l'Académie de Bordeaux 160 avenue de Verdun Bâtiment E 33700 MERIGNAC
in front of the jury composed of
- Caroline BULF - Maîtresse de conférences - Université de Bordeaux - Directeur de these
- Fabien EMPRIN - Professeur des universités - Université de Reims Champagne-Ardennes - Examinateur
- Lalina COULANGE - Professeure des universités - Université de Bordeaux - Examinateur
- Eric MOUNIER - Maître de conférences - Université Paris-Est Créteil - Examinateur
- Eric RODITI - Professeur des universités - Université Paris Cité - Rapporteur
- Julie HOROKS - Professeure des universités - Université Paris-Est Créteil - Rapporteur
This research investigates the professional gestures of first-grade teachers working in French priority education areas, focusing on the teaching of the decimal and positional number system, especially numbers from 60 to 79. Its main goal is to understand how scaffolding practices support or hinder learning among struggling pupils, through the analysis of classroom sessions, teaching materials, and comparative case studies. The theoretical framework combines mathematics education theories on number sense, semiotic registers (Duval, 1993), learning obstacles (Bachelard, Brousseau), and professional gestures (Bucheton & Soulé, 2009). Three first-grade classes were observed, each using a different resource (Maths au CP, Haut les Maths, and the Heuristic Mathematics Method). The methodology integrates qualitative analysis (a priori and a posteriori studies of teaching sessions, detailed coding of teacher talk and scaffolding gestures) with quantitative processing (frequency and typology of interventions), and introduces an original tool—the “tree of possibilities” (Blanchouin et al., 2022) —to visualize and compare teaching choices and their learning effects. The results highlight three key levers in the acquisition of place-value understanding: - the explicit coordination of semiotic registers (verbal, symbolic, iconic), - the richness and function of teachers' language gestures, - the didactic use of errors and obstacles as learning opportunities. Findings reveal notable contrasts between teachers: while some successfully turn pupils' mistakes into shared conceptualization moments, others maintain a strong guidance that limits students' cognitive autonomy. Language appears as a decisive mediation tool for conceptual understanding and regulation. The study also sheds light on the specific conceptual challenges faced by pupils regarding the decimal and positional system. Methodologically, the research offers an innovative combination of didactic and interactional analysis supported by visual modeling. Practically, it contributes to teacher education by identifying key components of effective scaffolding and by proposing training directions: anticipating obstacles, coordinating registers, developing explicit language-based mediation, and transforming student errors into teaching resources.
Cultural heritage as a strategic issue. The case of the Islamic State in Iraq and Syria (2014-2019)
by Eva PORTEL (Centre Emile Durkheim)
The defense will take place at 14h00 - IEP Sciences Po Bordeaux, 11 allée Ausone, 33600 Pessac
in front of the jury composed of
- Mathilde LELOUP - Maîtresse de conférences - Université Paris 8 - Examinateur
- Anthony AMICELLE - Maître de conférences - Sciences Po Bordeaux - Examinateur
- Jean-Vincent HOLEINDRE - Professeur des universités - Paris 2 Panthéon-Assas - Examinateur
- Chiara RUFFA - Professeure des universités - Sciences Po - Rapporteur
- Koen VLASSENROOT - Full professor - Université de Gand - Rapporteur
This dissertation investigates the strategic gains that attacks against cultural heritage bring to belligerents in the course of an armed conflict based on the case of the Islamic State in Iraq and Syria (IS). The core argument is that attacks can be analysed as a resource in three different ways: financial, military and propagandistic. Those three dimensions are exploited by IS to reinforce its position in the war. Hence, the research aims at answering the following question: what are the strategic gains offered by attacks against cultural property in times of armed conflict. The research begins by noting the lacuna in theoretical studies about the role of cultural heritage in armed conflict. Heritage is more often considered an instrument of peace or a collateral damage of violence. In contrast, this study seeks to theorize heritage as a resource for belligerents, that is, as something strategically used during wartime. After outlining the methodological challenges posed by such a subject, the dissertation identifies three dimensions that illustrate the link between heritage and warfare: 1) Cultural heritage is a financial resource. The establishment of a monopoly over looting and trafficking in cultural goods provides IS with financial income. This control supports the creation of a quasi-administrative structure, which serves as a political foundation for IS's legitimacy. Rivalries over the control of trafficking networks fuel local conflict. At the international level, the trafficking of cultural property becomes part of the broader definition of international security and a tool in the fight against terrorism. 2) Cultural heritage is a military resource. The dissertation presents a typology of how heritage is used during armed confrontations: for logistical or defensive purposes; to initiate or conduct warfare against an enemy (to start a war, to attack, or to confront the adversary); as part of a retaliatory response; and as a tool of coercion. 3) Cultural heritage is a propagandistic resource. The large-scale dissemination of images showing cultural destruction through IS propaganda channels plays a key psychological role in the conflict and engages a wide variety of actors involved in the war.