ED Entreprise Economie Société
Migration, Signaling, and Trust : Three Essays in Labor and Behavioral Economics
by Mael ASTRUC--LE SOUDER (BSE - Bordeaux sciences économiques)
The defense will take place at 15h00 - Salle des thèses 16 Av. Léon Duguit, bâtiment C1, 33600, Pessac
in front of the jury composed of
- Olivier BARGAIN - Professeur des universités - Université de Bordeaux - Directeur de these
- Isabelle CHORT - Professeure des universités - Université de Pau et des Pays de l'Adour - CoDirecteur de these
- Astrid HOPFENSITZ - Professeure - EMLyon - Rapporteur
- Sylvie BLASCO - Professeure des universités - Université Caen Normandie - Rapporteur
- Jérôme VALETTE - Maître de conférences - Université Paris 1 Panthéon Sorbonne - Examinateur
This dissertation examines how individuals respond to economic and informational changes, and how these responses shape observed outcomes. Across three essays in labor and behavioral economics, it combines quasi-experimental and experimental methods to identify causal effects and study their underlying mechanisms. The first chapter studies migration in Spain, showing small positive effects on employment, no impact on earnings, and significant behavioral responses, particularly geographic mobility. The second chapter analyzes academic signaling using a fuzzy regression discontinuity design, finding that honors increase short-term employment and earnings, consistent with better matching and employer learning. The third chapter shows experimentally that exposure to threatening information reduces trust and hope, highlighting the role of emotions.
ED Sciences de la Vie et de la Santé
From inflammation to nutrition, impact of the environment in neurodevlopmental disorders
by Pauline MONGUILLON (Nutrition et Neurobiologie Intégrée)
The defense will take place at 14h30 - Broca Amphithéâtre Broca Centre Broca Nouvelle-Aquitaine 146 rue Léo-Saignat 33076 Bordeaux Cedex
in front of the jury composed of
- Jean-Christophe DELPECH - Chargé de recherche - NutriNeuro - Directeur de these
- Laetitia DAVIDOVIC - Directrice de recherche - Institut de pharmacologie moléculaire et cellulaire - Rapporteur
- Morgane THION - Chargée de recherche - Collège de France - Rapporteur
- Véronique PERRIER - Directrice de recherche - Institute for Neurosciences Montpellier - Examinateur
- Freddy JEANNETEAU - Directeur de recherche - Institut de Génomique Fonctionelle - Examinateur
- Andreas FRICK - Directeur de recherche - Neurocentre Magendie - Examinateur
Various environmental influences are known to increase the risk of neurodevelopmental disorders (NDDs), such as autism spectrum disorder (ASD), including perinatal inflammation and dietary factors. Perinatal inflammation induces long-lasting activation and modification of microglia, leading to alteration of the developing brain programming. Relevant models are the Maternal Immune Activation (MIA) and the postnatal Interleukin-1β (IL-1β) injection models, involving injections of inflammatory agents during either gestation or the first days after birth. Previous studies established that offspring from MIA and IL-1β models exhibit cellular NDD phenotypes, initially observed primarily in males. In addition, a microglia renewal approach using a CSF1R inhibitor (PLX5622) in the MIA model successfully restored social behaviour abilities at adulthood in males. Here, we aim to explore the potential shared benefits of microglia renewal strategy on NDD phenotypes at adulthood using two rodent models of NDD: MIA and IL-1β models, in both sexes. Our results indicate that the microglia renewal partially restores deficits induced by the models on social and cognitive dimensions, including a consistent restoration of sociability deficits in males and females from both models at adulthood. Given the invasive nature of microglia renewal, we further investigated the mechanisms underlying its beneficial effects. First, we managed to identify the interferon-γ pathway as a potential master regulator of microglia response to cellular renewal in MIA condition, giving us a target to causally link the beneficial effect of our PLX approach onto MIA-induced behavioural deficits at adulthood. Then, we demonstrated that, in our experimental condition, the effects of PLX may rely on different pathways depending on the sex: while interferon-γ receptor is necessary to observe the rescue of social deficits in females, a knockout of this receptor does not alter the effects of microglia renewal in males. In a second axis, we investigated a specific inflammatory risk factor for NDDs: food consumption during development. Regarding dietary risk factors, we focused on ultra-processed food, and more specifically what distinguishes them from other alimentary products: food additives. We studied the effect of titanium dioxide (TiO2 – E171) and silicon dioxide (SiO2 – E551) from gestational period on brain development, alone or in combination at doses relevant to human exposure, to reflect realistic human consumption. We revealed that exposure to TiO2 and SiO2 induces deficits in behaviour during the developmental period, associated with cognitive alterations later in life at juvenile and adult periods, recapitulating key NDD features. These behavioural alterations are associated with an altered inflammatory profile in several brain structures playing a key role in NDDs, prefrontal cortex and hippocampus, specific to toxicant. Overall, my PhD project aims to understand how environmental factors during development can induce NDD phenotype and provides novel knowledge on innovative interventional strategies notably targeting microglia to restore optimal brain functions at adulthood for individuals with NDDs.
ED Sciences Physiques et de l'Ingénieur
Development of a GHz burst mode pulsed laser based on an electro-optical frequency comb: applications to ultrasonics.
by Paolo PARIS (Laboratoire Photonique, Numérique & Nanosciences)
The defense will take place at 9h30 - Amphithéâtre INP Avenue des facultés INP Bordeaux 33405 Talence
in front of the jury composed of
- Giorgio SANTARELLI - Ingénieur de recherche - Université de Bordeaux - Directeur de these
- Eric CORMIER - Professeur des universités - Université de Bordeaux - CoDirecteur de these
- Christ GLORIEUX - Professor - Katholieke Universiteit Leuven - Rapporteur
- Hugues GUILLET DE CHATELLUS - Directeur de recherche - Université de Rennes - Institut FOTON - Rapporteur
- Thomas PEZERIL - Directeur de recherche - Université de Rennes - Institut de Physique de Rennes - Examinateur
- STEFAN DILHAIRE - Professor - Laboratoire Ondes et Matière d'Aquitaine - Examinateur
Using an electro-optical frequency comb fabricated in our laboratory, we have developed a pulsed laser source that delivers bursts of pulses with a repetition rate continuously adjustable between 11 GHz and 18 GHz. Each burst contains at least five pulses. This source is used to generate acoustic pulses and measure their propagation via time-domain Brillouin scattering (TDBS). The novelty lies in replacing the single-pulse excitation and detection commonly used in TDBS experiments with bursts of optical pulses to generate a narrow-band acoustic wave and make the detection frequency-sensitive. To conduct this study, a TDBS pump-probe setup was constructed in the laboratory with the feature of being able to switch between a single-pulse and multi-pulse source. Single-pulse Brillouin measurements performed on various materials validated the experimental setup. Multi-pulse experiments demonstrate that a Brillouin signal can be measured using multi-pulse excitation and detection. Measurements in silica glass and MgO (111) crystal revealed that varying the pulse rate changes the amplitude of the Brillouin oscillations, which reaches a maximum when the pulse rate equals the Brillouin frequency or one of its subharmonics. Increasing the number of pulses per burst enhances the sensitivity to the pulse rate. These results are corroborated by a theoretical study of multi-pulse excitation and detection. The experiments and the theoretical model show that replacing a single pump pulse with a burst of less intense pulses results in a similar Brillouin amplitude. Such a result could have interesting applications on sensitive samples, such as in biology. This work validates the operation of the multi-pulse pump-probe experiment in TDBS. It paves the way for acoustic measurements in the frequency domain. An alternative application of the experimental setup is the measurement of magnetic precession via the Magneto-Optical Kerr Effect (MOKE). Initial MOKE experiments show that precession measurements can be performed in the multi-pulse case.