ED Mathématiques et Informatique
Aggregation techniques for solving large-scale dynamic programming formulations
by Luis LOPES MARQUES (IMB - Institut de Mathématiques de Bordeaux)
The defense will take place at 14h00 - Salle de conférences Institut de Mathématique de Bordeaux, Bâtiment A33 351 Cr de la Libération, 33400 Talence
in front of the jury composed of
- Francois CLAUTIAUX - Professeur des universités - Université de Bordeaux - Directeur de these
- Olivier BEAUMONT - Directeur de recherche - Centre Inria de l'Université de Bordeaux - Examinateur
- Gaël GUILLOT - Maître de conférences - Centre Inria de l'Université de Lille - Examinateur
- Fabien LEHUéDé - Professeur des universités - Laboratoire des Sciences du Numérique de Nantes - Rapporteur
- Sandra U. NGUEVEU - Maîtresse de conférences - Laboratoire de recherche spécialisé dans l'analyse et l'architecture des systèmes - Rapporteur
In this thesis, we are interested in problems that can be formulated as a sequence of decisions, where dynamic programming is a suitable modeling paradigm. To solve large-scale problems, we study aggregation and disaggregation methods that allow us to construct relaxations of the problem, which are solved to obtain optimistic solutions to these problems. Iterative algorithms are then designed from these relaxations, where the relaxations provide less optimistic solutions as the number of iterations increases. In this thesis, we first provide a literature review of the aggregation and disaggregation methods in the context of dynamic programming formulations. Then, we propose a problem modeling the aggregation of vertices in decision graphs of dynamic programs to construct relaxations and show that many aggregation methods in the literature are special cases of this problem. We then study an application of network flow formulations in a decision hypergraph, and extend some aggregation methods to this case. To validate our approaches, we present computational results on a set of different problems and compare them to similar approaches in the literature. We conclude this thesis with a discussion on the results obtained and propose some perspectives for future work.
ED Sciences Chimiques
Synthesis of advanced functional materials via bipolar electrochemistry for catalytic applications
by Ruchao GAO (Institut des Sciences Moléculaires)
The defense will take place at 14h00 - Amphithéâtre 3 ENSMAC, 16 avenue Pey Berland, 33607 Pessac
in front of the jury composed of
- Alexander KUHN - Professeur - Bordeaux INP - Directeur de these
- Hubert GIRAULT - Professeur - Ecole Polytechnique Fédérale de Lausanne - Rapporteur
- Mathieu ETIENNE - Directeur de recherche - CNRS Nancy - Rapporteur
- Nicolas MANO - Directeur de recherche - CNRS Bordeaux - Examinateur
- Lin ZHANG - Professeur - Henan University - CoDirecteur de these
- Dodzi ZIGAH - Professeur - Université de Poitiers - Examinateur
Bipolar electrochemistry enables wireless asymmetric modification of both conducting and semiconducting objects, thereby allowing the fabrication of Janus particles. When an object is placed in an electric field generated by two driving electrodes, a potential difference is established at its two ends. Redox reactions will be triggered simultaneously at opposite ends once the potential difference is sufficiently high. By adjusting the direction and intensity of the electric field, this modification can be precisely controlled. The aim of this thesis is to synthesize advanced functional materials using bipolar electrochemistry and exploring their catalytic applications. First, graphene monolayers were introduced as a model 2D material to investigate the feasibility of bipolar electrodeposition. Metals, metal coordination compounds, and polymers can be deposited at desired positions of a graphene monolayer, resulting in multifunctional hybrid objects with self-propulsion and chemiluminescence properties. The modified graphene monolayer can also be used to fabricate enzymatic swimmers with controlled dynamic behavior by applying an external magnetic field. Furthermore, by coupling bipolar electrochemiluminescence with a magnetic field, a graphene-based 2D rotor is designed in order to combine bipolar electrochemistry with rotational dynamics. Then, the scope of bipolar electrochemistry was also extended to MXene microsheets to evaluate the applicability of this approach to other 2D materials. In the last part of this thesis, light-assisted bipolar electrochemistry was introduced for the modification of semiconducting materials. This synergy of light and electric field enables selective modification of one side of semiconductor particles. By adjusting the electric field intensity and the duration of application, the size of the deposited area could be precisely tuned. Finally, the site-selective modified semiconductor particles show enhanced photocatalytic performance for environmental remediation.
FABRICATION OF SILICON-BASED NANOSTRUCTURES: ALTERING OPTICAL PROPERTIES THROUGH MORPHOLOGY AND COMPOSITION.
by Emmanuel IDOWU (ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux)
The defense will take place at 14h00 - Auditorium de l'ICMCB 87 Av du Dr Albert Schweitzer 33607 Pessac
in front of the jury composed of
- Glenna DRISKO - Directrice de recherche - Université de Bordeaux - Directeur de these
- Stephane PAROLA - Professeur - Laboratoire de Chimie ENS de Lyon - Rapporteur
- Cyrille HAMON - Chargé de recherche - Laboratoire de physique des Solides - Rapporteur
- Gilles BOURRET - Associate Professor - Paris-Lodron University of Salzburg - Examinateur
- Laurence CROGUENNEC - Directeur de recherche - Institut de Chimie de la Matière Condensée in Bordeaux - Examinateur
- Virginie PONSINET - Directeur de recherche - Paul Pascal Research Center (CRPP) - CoDirecteur de these
Nanophotonics research has sought to create nanostructures with strong directional optical scattering to control light propagation at the nanoscale. This directional scattered light has a range of potential technological applications, such as perfectly transmitting (or reflecting) broadband optical coatings, enhanced Raman scattering, nanoantennas, nonlinear optics, etc. Subwavelength-sized Si particles (100 – 200 nm) interact with visible and near-infrared light offering low optical losses and present strong electric and magnetic resonances. These resonances can combine to produce pure forward scattering. However, there is only partial spectral overlap of the electric and magnetic responses resulting in relatively weak total scattering efficiencies. The different strategies to improve the spectral overlap of these two modes in Si particles include creating non-spherical morphologies (e.g., nanoellipse, nanowires, etc), core-shell architectures, or assembling Si particles into arrays (such as metasurfaces). Hence, this thesis aims to develop these silicon-based nanostructures via different bottom-up synthesis approaches and study their optical properties. First, we present a two-step solution approach to prepare Si@Au core-shell particles with controllable shell thickness below 10 nm. The Au nanoparticle density around the Si particles can be increased by performing a second functionalization/deposition step. We study the electromagnetic response of the particles using single-particle scattering spectroscopy and electron energy loss spectroscopy (EELS). Our results were compared with reference Si spheres and SiO2@Au core-shell particles, this allows us to establish the contribution from the Au decoration to the optical response of the hybrid particles. To further elucidate the nature of the electromagnetic response of the particles, we performed T-matrix simulations which replicated our experimental findings and showed the importance of controlling the shell/core dimensions and the need for a continuous shell to maximize forward scattering. Furthermore, a synthesis pathway was established to make Si@Ag core-shell particles. These particles were also characterized using the different optical techniques adopted for the Si@Au particles. It remains a future study to extend this library of core-shell nanostructures to dielectric shells such as Si@ - SiO2, ZrO2, TiO2, etc. Second, we synthesized silicon nanowires via the thermal disproportionation reaction of a silicon-rich oxide in the presence of different metallic nanoparticles, which we assume catalyzes the wire growth. We used different metal catalysts such as Au, Ag, Fe2O3, and TiO2 nanoparticles to grow the silicon nanowires. The silicon nanowires have a core of elemental silicon with a shell of 10–20 nm of silicon oxide. The length of the nanowires is between 1–6 µm, rendering them highly anisotropic. The optical properties of these nanowires were studied. To achieve a higher degree of control over the morphology and to compare to other nanowire growth techniques, we performed in situ environmental studies to follow in real time the formation of these nanowires. Such knowledge can help us improve silicon nanowire yield and scalability. Lastly, we present the sol-gel synthesis of mesoporous ellipsoidal silica particles. In terms of optical applications, we tried to reduce these particles to elemental silicon via magnesiothermic reduction as they would show asymmetric and improved light scattering properties. However, the major challenges encountered in this attempt include the control over particle morphology, aggregation, and porosity.
Colloidal self-assembly guided by the formation of DNA triplexes
by Matthieu SOULA (Centre de Recherche Paul Pascal)
The defense will take place at 10h00 - Amphithéâtre du CRPP CRPP, 115 Avenue du Dr Albert Schweitzer, 33600 Pessac
in front of the jury composed of
- David PEYRADE - Directeur de recherche - Université Grenoble Alpes - Rapporteur
- Loic JIERRY - Professeur - Université de Strasbourg - Rapporteur
- Cécile ZAKRI - Professeure - Université de Bordeaux - Examinateur
- Didier GASPARUTTO - Directeur de recherche - Université Grenoble Alpes - Examinateur
The self-assembly of micro- or nanoscale components offers promising perspectives for the design of complex architectures, enabling the bottom-up fabrication of functional materials. Grafting DNA fragments onto the surface of colloidal building blocks provides them with specific interaction potentials and guides their assembly into predefined structures. While most studies have focused on the assembly of colloidal entities through DNA duplex formation, alternative secondary DNA structures have received relatively little attention. In this work, we explore the potential and limitations of DNA triplex formation for programming the assembly of colloidal building blocks. For this purpose, particles grafted with surface-bound DNA strands and an additional third strand in solution are required. We investigated the influence of temperature, third-strand concentration, and buffer composition on particle interactions and their self-assembly capability. Furthermore, we examined the influence of pH on parallel triplex formation, offering the possibility of modulating particle assembly through the addition of an acid or a base.
ED Droit
Electronic money in European, African regional and OHADA banking spaces
by Pierre FOUGOU (INSTITUT DE RECHERCHE EN DROIT DES AFFAIRES ET DU PATRIMOINE)
The defense will take place at 14h00 - Salle des Thèses Université de Bordeaux, Campus Montesquieu, 16 avenue Léon Duguit
in front of the jury composed of
- Marianne LECENE-VILLEMONTEIX - Maîtresse de conférences - Université de Bordeaux - Directeur de these
- Myriam ROUSSILLE - Professeur - Université du Mans - Rapporteur
- Jérôme LASSERRE CAPDEVILLE - Maître de conférences - Université de Strasbourg - Rapporteur
- Bernard SAINTOURENS - Professeur émérite - Université de Bordeaux - Examinateur
As a major innovation, electronic money has established itself in the financial ecosystem by enabling economic agents to meet distinct yet complementary needs in both Europe and Africa. To this end, the analysis of electronic money through the lens of these two geographical areas, and specifically of three banking zones — the EU, WAMU, and CEMAC — has notably highlighted the various dynamics generated by this modern instrument. In Europe, electronic money represents a pragmatic response to micropayments in a largely banked economy. In Africa, it constitutes far more than a simple solution for micropayments; it serves as an essential lever for financial inclusion among predominantly unbanked populations. This thesis offers a comparative legal analysis of electronic money in these two geographical areas, revealing contrasting socio-economic contexts as well as radically different perspectives despite a common legal understanding. In order to conduct an analysis that integrates both the legal and technological evolution of electronic money and digital payment methods, the first part of the analysis will be devoted to examining the qualification criteria for electronic money. This will underscore that the banking zones covered by the study share a common legal understanding of the matter, while having different technological appropriations that are illustrated by distinct forms of electronic money depending on whether one is in Europe or in the WAEMU and CEMAC banking zones. Subsequently, the analysis will continue with the study of technological innovations and legal transformations that have occurred with the emergence of electronic money. This analysis will also serve as the cornerstone of the forward-looking approach that underpins this thesis, as it will not only ground reflections on the necessary evolution of monetary criteria in the face of emerging digital payment methods, but will also advocate for a paradigm shift consisting primarily of reducing the scope of the traditional monetary monopoly and establishing more dynamic competition among payment methods. Within this forward-looking approach aimed at improving the efficiency of payment methods and ensuring more optimal financial inclusion, it will also be proposed that electronic money be granted legal tender status in Africa, and that a central bank electronic money token be established based on distributed ledger technology, in order to promote African economic integration. In sum, electronic money represents far more than a mere technical innovation. It is and can become a genuine vector for profound transformation of financial systems and monetary law. Its legal framework must therefore continue to evolve to support its exponential development. In Africa particularly, regulators would benefit from making it a privileged instrument for financial inclusion and regional economic integration, by opting for ambitious legal and institutional reforms. This research thus proposes to rethink the foundations of banking and monetary law not only to adapt electronic money to the realities of an increasingly digitized and less centralized economy, but especially to make this modern instrument a tool conducive to the needs of economic integration in Africa.
ED Sciences de la Vie et de la Santé
The Role of the Histone Methyltransferase Prdm2 in the Prelimbic Cortex: Behavioral and Molecular Implications in Cocaine-Related Behaviors in Rats
by Giulia DE MAIO (Neurocentre Magendie)
The defense will take place at 14h00 - Salle de conférence 146 rue Léo Saignat 33077 Bordeaux cedex - France Neurocentre Magendie - Inserm U1215
in front of the jury composed of
- Marcello SOLINAS - Directeur de recherche - Laboratoire de Neurosciences Expérimentales et Cliniques, Inserm / Université de Poitiers (Poitiers) - Rapporteur
- Emmanuel VALJENT - Directeur de recherche - Institut de génomique fonctionnelle - CNRS / Inserm / Université de Montpellier - Rapporteur
- Christelle BAUNEZ - Directrice de recherche - Institut de Neurosciences de la Timone, CNRS / Aix Marseille Université - Examinateur
- Mickael NAASSILA - Professeur des universités - Groupe de Recherche sur l'Alcool & les Pharmacodépendances, Inserm / Université de Picardie Jules Verne - Examinateur
Cocaine use is rising worldwide, particularly in Europe, with prevalence among 15–64-year-olds increasing. About 20% of users develop addiction, a chronic disorder marked by loss of control over drug seeking and drug taking. No approved pharmacotherapies exist, and behavioral treatments remain limited. Epigenetic mechanisms, i.e. heritable regulation of gene expression without altering DNA sequence, are increasingly recognized in addiction-related neuroplasticity. While cocaine alters histone modifications and DNA methylation in the mesocorticolimbic system, most studies rely on non-compulsive models, making it difficult to distinguish drug exposure-driven from addiction-specific molecular changes. Building on studies in alcohol addiction, where the histone methyltransferase Prdm2 emerged as a key player, this thesis investigates Prdm2 as an epigenetic marker and modulator of compulsive cocaine use. Prdm2 methylates lysine 9 on histone H3, regulating chromatin accessibility and transcription. In alcohol post-dependent rats, Prdm2 expression is reduced in the dorsomedial prefrontal cortex (dmPFC), and local knockdown (KD) via AAV-shRNA promotes compulsive drinking and stress-induced relapse. Using the DSM-based ‘3crit' rat model of cocaine addiction, which identifies ~20% of animals as “addicted-like” after prolonged cocaine self-administration, we measured Prdm2 mRNA levels in the dmPFC via qPCR. Similar to alcohol models, Prdm2 expression was reduced in addicted-like rats as compared to non-addicted rats, whose levels were similar to cocaine naïve rats. Moreover, Prdm2 levels negatively correlated with individual addiction scores: the lower the expression the more pronounced the maladaptive self-administration behavior. To probe causality, we knocked down Prdm2 expression before cocaine exposure at a high dose (0.8 mg/kg/infusion). While KD did not induce addiction-like behavior directly, it altered cocaine self-administration: KD rats stabilized intake at lower levels and maintained stable responding at reduced doses, suggesting enhanced cocaine effects without compulsive use at this stage. However, when KD was induced after cocaine self-administration training, KD rats escalated intake over time, whereas controls remained stable, indicating increased vulnerability to cocaine-induced seeking in Prdm2-deficient rats. To assess whether these effects extended beyond drug rewards, we evaluated sucrose self-administration using a comparable protocol alternating reward/no-reward access periods. KD rats showed increased overall sucrose intake. However, motivation and palatability indices (e.g., licks per delivery, performance in progressive ratio) were similar between groups. Interestingly, KD rats adapted more rapidly to reward availability changes, suggesting a broader role for Prdm2 in regulating reward-related behaviors. To uncover molecular mechanisms underlying these effects, we performed RNA-seq on dmPFC tissue from KD and control rats, both cocaine-naïve and cocaine-exposed. Prdm2 appeared to maintain synaptic integrity by repressing genes involved in vesicle trafficking, extracellular matrix remodeling, and astrocytic regulation. KD led to upregulation of these pathways, possibly lowering the threshold for cocaine-induced plasticity and promoting maladaptive drug-seeking. In summary, Prdm2 downregulation in the dmPFC is a specific molecular signature of cocaine addiction-like behavior, correlating with symptom severity. The behavioral and transcriptomic consequences of Prdm2 KD support its physiological role in adaptability to experimental contingencies, ultimately contributing to the regulation of control over cocaine-induced drug-seeking behavior. A key perspective of this work is to investigate the respective contributions of innately reduced Prdm2 expression and the long-term, cocaine-induced downregulation of Prdm2 in the transition from heightened to diminished control over maladaptive cocaine-seeking behavior.
Electrophysiologic, transcriptomic and morphologic plasticity of spinal GABAergic interneurons to decipher atypical mechanosensory perception in Autism
by Anna SAINT-JEAN (Neurocentre Magendie)
The defense will take place at 15h00 - Auditorium Centre Broca Nouvelle Aquitaine Centre Broca Nouvelle Aquitaine 146 Rue Leo Saignat 33077 Bordeaux Cedex
in front of the jury composed of
- Yves LE FEUVRE - Chargé de recherche - Université de Bordeaux - Directeur de these
- Ingrid BUREAU - Chargée de recherche - Université Aix-Marseille - Rapporteur
- Eric LINGUEGLIA - Directeur de recherche - Université Côte d'Azur - Rapporteur
- Matilde CORDERO-ERAUSQUIN - Directrice de recherche - Université de Strasbourg - Examinateur
- Graziella DI CRISTO - Full professor - Université de Montréal - Examinateur
- Amaury FRANCOIS - Chargé de recherche - Université de Montpellier - Examinateur
- Alexandre FAVEREAUX - Professeur des universités - Université de Bordeaux - Examinateur
Autism is characterized by impairments in social communication and interactions, as well as repetitive behaviours. Most people with autism also exhibit aberrant reactivity to sensory stimuli including tactile stimuli. In addition to being a major source of discomfort for autistic people, recent research suggests that tactile dysfunction may actually contribute to the development of the others core symptoms. This is why understanding the neural mechanisms behind tactile dysfunction is so important. Tactile information is perceived in the periphery and processed in the spinal cord under the control of inhibitory interneurons before being sent to higher brain structures. However, whether these inhibitory neurons undergo functional alterations in autistic models remains poorly understood. To explore the functional plasticity of spinal GABAergic interneurons (SGI) in autism, we used Fmr1-/y mice crossed with Gad1-GFP reporter lines. These mice exhibit haploinsufficiency for the Gad1 gene, which may interfere with the development of characteristic autistic phenotypes. We show that Fmr1-/y-Gad1-GFP mice display tactile deficits (longer latencies in tape removal test, decreased reactivity to brush stimulation), decreased anxiety in elevated plus maze, and social deficits, as typically observed in autistic models. Then, to characterize electrophysiologic, transcriptomic and morphologic properties of SGI in acute spinal slices we used the patch-seq technique. We observed that SGI exhibit altered excitability, characterized by an increased firing frequency of action potentials (AP) at low current injections, but a reduced frequency at high intensities compared to WT mice. This results in a narrower functional dynamic range, shifted toward lower-intensity stimulations. Importantly, transcriptomic analysis of recorded neurons reveals that these changes are restricted to a subpopulation of SGI expressing the parvalbumin (pvalb) and the neuropeptide Y (NPY) marker. Altogether, we suggest that functional alterations of SGI, particularly pvalb and NPY neurons in autism models disrupt tactile information processing upstream of the brain and may play a critical role in the development of sensory and social deficits characteristic of autism, underscoring their potential as therapeutic targets.
ED Sciences Physiques et de l'Ingénieur
Numerical modeling of mass transfer at fluids interfaces
by Cédric PALKA (I2M - Institut de Mécanique et d'Ingénierie de Bordeaux)
The defense will take place at 14h00 - Amphithéâtre C 351 Cours de la libération, 33400 Talence Campus Peixotto Bâtiment A29 RDC, Amphithéâtre C
in front of the jury composed of
- Arnaud ERRIGUIBLE - Professeur des universités - Université de Bordeaux - Directeur de these
- Dominique LEGENDRE - Professeur des universités - Toulouse INP - Rapporteur
- Cyprien SOULAINE - Chargé de recherche - Université d'Orléans - Rapporteur
- Sylvie BORDERE - Chargée de recherche - Université de Bordeaux - CoDirecteur de these
- Joelle AUBIN - Directrice de recherche - Toulouse INP - Examinateur
Mass transport and its transfer across interfaces in multiphase systems are crucial to many natural phenomena and industrial processes, ranging from geochemical reactions to various applications in chemical engineering. The development of numerical models is therefore essential for analyzing and optimizing these processes. In this work, we investigate flows coupled with phase transitions limited by species diffusion in a two-phase system composed of a liquid solution and a gaseous phase. Depending on the initial composition of the solution, undersaturated or supersaturated with respect to the solute, the volume of the gaseous phase decreases or increases. These variations lead to dissolution or precipitation phenomena. Since diffusion is the limiting mechanism, the interface remains at thermodynamic equilibrium and exhibits a concentration discontinuity. Few studies have focused on the numerical modeling of dissolution and precipitation phenomena, and research focused specifically to precipitation is even scarcer. This challenge arises from two major difficulties. The first is accounting for phase volume variations induced by mass transfer, while preserving the concentration discontinuity at the interfaces. The second is incorporating the variations in partial molar volumes of the species involved in the transfer between liquid and gaseous phases. In this study, we implemented in the computational fluid dynamics code Notus a single-field CST (Continuous Species Transfer) formulation, which requires solving a single advection–diffusion equation for the species. In addition, we adopted an algebraic Volume of Fluid (VOF) approach based on the Compressive Interface Capturing Scheme for Arbitrary Meshes (CICSAM). Simulations performed in one-, two-, and three-dimensional configurations successfully reproduced dissolution phenomena. However, in order to remove interfacial instabilities during precipitation simulations, it was necessary to introduce a two-field-based discretization of source terms associated with phase volume variations in both the mass conservation equations and the transport equation of the volume fraction. This original approach enabled, for the first time, the simulation of gas-phase precipitation in a supersaturated solution using a single-field method. The validation of this numerical scheme for precipitation was carried out in one, two, and three spatial dimensions, by comparing gas-phase growth kinetics and concentration profiles with the exact solutions derived in this work. Furthermore, three-dimensional dynamic simulations of a rising bubble confirmed the relevance of this single-field discretization for precipitation modeling. Finally, in the last part of this study, we propose an original extension of the single-field model to compressible two-phase systems. The model is successfully applied to several benchmark cases involving two compressible phases.
ED Sciences et environnements
Toward a forest bocage: broadleaved hedgerows as a Nature-Based Solution to enhance the resistance of plantation forest landscapes
by Nattan PLAT (BIOGECO - BIOdiversité, Gènes & Communautés)
The defense will take place at 14h00 - Salle des chênaies INRAE BIOGECO 69 route d'Arcachon 33610 Cestas-Pierroton
in front of the jury composed of
- Hervé JACTEL - Directeur de recherche émérite - Université de Bordeaux - Directeur de these
- Andrea BATTISTI - Professeur - University of Padova - Rapporteur
- Annie OUIN - Professeure des universités - ENSAT Toulouse - INRAE Dynafor - Rapporteur
- Audrey ALIGNIER - Chargée de recherche - INRAE BAGAP - Examinateur
- Marc DUFRENE - Professeur - Université de Liège - Examinateur
In the context of global change, forest ecosystems are increasingly exposed to disturbances, particularly insect pest outbreaks. Monospecific plantation forests are particularly vulnerable and also support lower biodiversity compared to semi-natural forests. Forest diversification, whether implemented at the stand or landscape scale, is a promising approach to enhancing their resistance, but this raises management and governance challenges that often slow down or hinder its implementation. In this thesis, we applied the concept of Nature-Based Solutions to explore the potential benefits of establishing a network of broadleaved hedgerows within a pine plantation landscape, referred to as a “forest bocage”. Inspired by the traditional “bocage” (i.e., agricultural landscape with hedgerows), this forest landscape diversification strategy is based on two main hypotheses: (1) hedgerows can host natural enemies that help control pests (i.e., conservation biological control), and (2) they promote biodiversity conservation. These hypotheses were tested in the Landes de Gascogne Forest in southwestern France, a large forested area of over one million hectares, dominated by monospecific stands of maritime pine (Pinus pinaster). Using existing broadleaved hedgerows and remnants (considered as source habitats for forest biodiversity), we assessed their effects on infestation by the pine processionary moth (Thaumetopoea pityocampa) and on the activity of its avian and bat predators. In parallel, we compared multi-taxonomic biodiversity (i.e., understorey vegetation, butterflies, carabids, spiders, birds and reptiles) between broadleaved hedgerows and pine stand borders, and characterized hedgerow structure using an innovative airborne LiDAR approach. Our results show that broadleaved hedgerows reduce pine processionary moth infestations through a barrier effect that limits host tree detection by adult moths. The great tit (Parus major), particularly active in hedgerows during spring, contributes to the winter regulation of processionary caterpillars. Moreover, multi-taxonomic biodiversity was significantly higher in hedgerows than in pine edges, with hedgerows harbouring more forest specialist and rare species. LiDAR data analyses also revealed that hedgerows with dense canopy harbour more forest specialist species, while high structural heterogeneity in canopy and understory promotes a greater multi-taxonomic biodiversity. By demonstrating that broadleaved hedgerows can simultaneously mitigate pest damage and restore biodiversity, this thesis highlights that the “forest bocage” represents a relevant Nature-Based Solution to enhance the resistance of pine plantation landscapes against pest insects. Further research is nonetheless needed to assess their potential role in mitigating abiotic disturbances, particularly storms and wildfires.
ED Sociétés, Politique, Santé Publique
Study of teaching and learning conditions for dividing a rational number by a rational number in secondary school Choosing an entry: the act of measuring by commensuration
by Aurélien OVIDE (Laboratoire d'épistémologie et didactiques disciplinaires, professionnelle et comparée de Bordeaux)
The defense will take place at 14h00 - Amphi B 351 Cours de la Libération Bâtiment A29 33405 Talence
in front of the jury composed of
- Lalina COULANGE - Professeure des universités - UNIVERSITÉ DE BORDEAUX - Directeur de these
- Anne-Cécile MATHÉ - Maîtresse de conférences - UNIVERSITÉ CLERMONT AUVERGNE - Rapporteur
- Christine CHAMBRIS - Professeure des universités - CY CERGY PARIS UNIVERSITÉ - Rapporteur
- Martine JAUBERT - Professeure émérite - UNIVERSITÉ DE BORDEAUX - Examinateur
- Jean-Luc DORIER - Professeur - UNIVERSITÉ DE GENÈVE - Examinateur
- Éric RODITI - Professeur des universités - UNIVERSITÉ PARIS CITÉ - Examinateur
- Jérôme PROULX - Professeur - UNIVERSITÉ DU QUÉBEC À MONTRÉAL - Examinateur
Based on the results of didactic engineering for research on rational numbers, the situation of the thickness of sheets of paper, we explore new directions of research able to produce a process for developing the division of a rational-measure by a rational-measure using commensuration as a defining model of the fraction. Our research is rooted in the study of rational numbers in relation to measurement. This context leads us to explore the potential of the commensuration meaning of the fraction in situations organised around a variety of multiplicative relationships and (relative) units. These possibilities are put into perspective with recommendations documented in educational literature, published by educational institutions and drawn from school textbooks. The theoretical framework of the Theory of Didactic Situations leads us to develop a phenomenotechnical didactic engineering approach based on rational-measurement and multiplicative relationships. A posteriori analyses of materials collected during an experiment with 8th grade students on the engineering process of dividing a rational measure by a rational measure are supported by a second theoretical contribution, the hypothesis of the "scholarly disciplinary discursive community".