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Essay topic Essays on the Empirical Analysis of Crypto-Assets: Market Efficiency, Peg Failures, and Financial Flights Composition of the Jury Promoter: Prof. Jean-Yves Gnabo (UNamur)Other jury members: Prof. Sophie Béreau (UNamur)Prof. Kris Boudt (UGent)Prof. Sarah Bouraga (EM Normandie)Prof. Jérôme Lahaye (Fordham University)Jury president: Prof. Corentin Burnay (UNamur)

Rubber boots, overalls, the bleating of ewes, the smell of straw... The scene is set. On the farm of the Centre de Recherche Ovine, located in the Namur countryside, veterinary students live, for the space of a few days, to the rhythm of lamb births. An intense, formative experience, filled with technical gestures and emotions, supervised by veterinarians from the University of Namur.

Abstract Primarily described as an alarmone, secondary messenger (p)ppGpp, when accumulated, binds to many targets involved in DNA replication, translation, and transcription. In the asymmetrically-dividing a-proteobacterium Caulobacter crescentus, (p)ppGpp has been shown to strongly impact cell cycle progression and differentiation, promoting the non-replicating G1/swarmer phase. Mutations in the major subunits of transcriptional complex, b or b' subunits, were able to display the (p)ppGpp-related phenotypes even in the absence of the alarmone. We identified that the transcriptional holo-enzyme, RNA polymerase (RNAP) is a primary target of (p)ppGpp in C. crescentus. Furthermore, mutations that inactivate (p)ppGpp binding to RNAP annihilated the (p)ppGpp-related phenotypes and phenocopied a (p)ppGpp0 strain. Our RNAseq analysis further elucidated the changes in the transcriptional landscape of C. crescentus cells displaying different (p)ppGpp levels and expressing RNAP mutants. Since the DNA replication initiation protein DnaA is required to exit the G1 phase, we observed that it was significantly less abundant in cells accumulating (p)ppGpp. We further explored its proteolysis under the influence of (p)ppGpp. Our work suggests that (p)ppGpp regulates cell cycle and differentiation in C. crescentus by reprogramming transcription and triggering proteolytic degradation of key cell cycle regulators by yet unknown mechanisms. In Part II, we identified two σ factors belonging to the ECF family that might be involved in this (p)ppGpp-accompanied phenotypes. In Part III, we propose an overlapping role of the ω subunit, RpoZ, and the heat shock subunit, RpoH, in carbon metabolism.JuryProf. Gipsi LIMA MENDEZ (UNamur), PresidentProf Régis HALLEZ (UNamur), SecretaryDr Emanuele BIONDI (CNRS-Université Paris-Saclay)Prof. Justine COLLIER (University of Lausanne)Dr Marie DELABY (Université de Montréal)

Abstract Estrogens originating from human and animal excretion, as well as from anthropogenic sources such as cosmetics, plastics, pesticides, detergents, and pharmaceuticals, are among the most concerning endocrine-disrupting compounds in aquatic environments due to their potent estrogenic activity. While their effects on fish reproduction are well documented, their impact on development, particularly metamorphosis, remains poorly studied. This hormonal transition, mainly controlled by the thyroid axis, is essential for the shift from the larval to the juvenile stage in teleosts.The effects of two contraceptive estrogens on zebrafish (Danio rerio) metamorphosis were evaluated: 17α-ethinylestradiol (EE2), a synthetic reference estrogen, and estetrol (E4), a natural estrogen recently introduced in a new combined oral contraceptive formulation. Continuous exposure from fertilization to the end of metamorphosis allowed the assessment of morphological changes, disruptions of the thyroid axis, and modifications of additional molecular pathways potentially involved in metamorphic regulation.EE2 induced significant delays and disturbances in metamorphosis, affecting both internal and external morphological traits, confirming its role as an endocrine disruptor of concern. In contrast, E4 did not cause any detectable morphological alterations even at concentrations far exceeding those expected in the environment, indicating a limited ecotoxicological risk. Molecular analyses showed that EE2 strongly affected thyroid signaling and energy metabolism during metamorphosis, whereas E4 induced only minor transcriptional and proteomic changes.This study provides the first evidence that EE2 can disrupt zebrafish metamorphosis and highlights the importance of including this developmental stage in ecotoxicological assessments. The results also suggest a larger environmental safety margin for E4, although further research is needed to clarify the mechanisms linking estrogen exposure to metamorphic regulation.JuryProf. Frederik DE LAENDER (UNamur), PresidentProf. Patrick KESTEMONT (UNamur), SecretaryDr. Sébastien BAEKELANDT (UNamur)Dr. Valérie CORNET (UNamur)Prof. Jean-Baptiste FINI (Muséum National d'Histoire Naturelle, Paris)Dr. Marc MULLER (ULiège)Prof. Veerle DARRAS (KULeuven)

In early September, the University of Namur hosted the first Main-Group Elements Reactivity Conference (MG-ERC). Over 100 researchers from 12 countries and 32 institutions gathered around Professor Guillaume Berionni. An event hailed as "one of the best chemistry conferences" by its prestigious guests.

SummaryAt a time when a stream of research was striving to reformulate quantum mechanics by abolishing operators and substituting functions, Wigner and Szilard proposed in 1932 a quasi-probability distribution defined on phase space thanks to wave functions. They did not explain its genesis.The first part of our thesis proposes a genesis of this quasi-distribution, based on the natural conditions it must fulfill. It briefly examines a pathology it suffers from: exhibiting negative values in certain subdomains of the phase space (hence the "quasi"), a pathology that does no harm to the calculation of mean values. She then shows how, if we take spin into account, with wave functions giving way to spinners, we are led, thanks to the calculation of mean values of observables, to a generalization of this quasi-distribution in the form of a Hermitian matrix. This approach is extended to the Wigner cross transform, i.e. to weak values.An important theorem, which has been the subject of a publication, is proved in the second part of our thesis. Using harmonic analysis, this result expresses weak values in terms of an integral over a Lie group acting on the Hilbert space under consideration. We give two particular examples: SU(2) and SO(3). The case of a quotient group is briefly discussed.In a third section, we recall the well-known link between Clifford algebras and two important equations of quantum physics: the Klein-Gordon and Dirac equations, and its generalization to Riemannian spacetimes.Finally, in a fourth section we introduce spin groups, and use the spin group Spin(3,2) in the context of the Wigner cross transform discussed in the first section.JuryProf. André FÜZFA (UNamur), PresidentProf. Yves CAUDANO (UNamur), SecretaryDr. Thomas DURT (Institut Fresnel and Ecole Centrale Marseille, Marseille, France)Prof. Romain MURENZI (Worcester Polytecnic Institute)Prof. Dominique LAMBERT (UNamur)Prof. Bertrand HESPEL (UNamur)Prof. André HARDY (UNamur)

A team of American researchers, with the help of Frédérik De Laender, professor in the Department of Biology at UNamur, has just published in the prestigious journal Nature. Their study describes how changing stream temperatures and human introductions of fish can alter river biodiversity in the USA.