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Jury Prof. Marielle BOONEN (UNamur), presidentProf. Henri-François RENARD (UNamur), secretaryProf. Claire HIVROZ (PSL University)Prof. Michel GHISLAIN (UCLouvain)Prof. Pierre VAN DER BRUGGEN (UCLouvain)Prof. Ludger JOHANNES (PSL University)Prof. Pierre MORSOMME (UCLouvain) Summary Clathrin-independent endocytosis (CIE) mediates the cellular uptake of endogenous and exogenous cargoes, including bacterial toxins and viruses. Endophilin A3-mediated endocytosis is a specific CIE mechanism that differs from fast endophilin-mediated endocytosis (FEME), with ALCAM and L1CAM being the first confirmed Endophilin A3-specific cargoes. Here, we report ICAM1 as a new Endophilin A3-dependent endocytic cargo. ALCAM and ICAM1 are important components of immune synapses (IS), which are polarized structures formed between immune cells and target cells, such as cancer cells. These molecules transduce essential co-stimulatory signals to T cells to help their effective activation and proliferation. We find that both ALCAM and ICAM1 serve as cargoes for retromer-dependent retrograde transport to the trans-Golgi network (TGN) in cancer cells. Interestingly, disrupting Endophilin A3-mediated endocytosis or retromer-dependent retrograde transport machinery impairs activation of autologous cytotoxic CD8 T cells, possibly by affecting the polarized redistribution of immune synapse components at the plasma membrane. Altogether, our findings demonstrate that CIE and retrograde transport are key pathways in cancer cells that promote the activation of cytotoxic CD8 T cells.

Jury Prof. Yves CAUDANO (UNamur), chairmanProf. André FÜZFA (UNamur), secretaryProf. Dominique LAMBERT (UNamur)Dr. Jérémy REKIER (Observatoire royal de Belgique et UCLouvain)Prof. Dr. Félix FINSTER (Regensburg University) Summary Sounding the Universe with a relativistic solar sailboat or Einstein-Dirac fermionsThe Universe exerts a curiosity on man that is both undeniable and fundamental. To unravel the mysteries of the Cosmos, man is driven to develop two major investigative strategies: direct exploration by sending space probes, and indirect exploration by observing cosmic electromagnetic fields, gravitational waves or particles such as fermions.Following these two strategies, in this thesis we develop, in the first approach (consisting of sending a space probe), a relativistic kinematic and dynamical model of photonic sails (light sails) with arbitrary reflectivity and absorbance, moving in a non-rectilinear manner with the aim of exploring interstellar space. The problem is to determine the sail's trajectory in a Minkowski spacetime, a four-dimensional variety. From detailed calculations, we obtain the sail's universe line in the laser reference frame as a function of the sail's proper time.The second approach applies the Two-State Vector Formalism and weak measurements to a homogeneous, isotropic cosmological framework. By coupling Dirac spinners to classical gravity, we calculate weak values of the energy-impulse tensor, the Z component of spin and pure states. Extending the work of Finster and Hainzl on Einstein-Dirac cosmology, we show that the accelerated expansion of the Universe can be interpreted as a consequence of post-selection. We also demonstrate that weak measurements can amplify signals using simpler equipment, thanks to judicious selection of the initial and final state vectors. In addition, this procedure highlights certain geometric properties of the Cosmos' three-dimensional space, offering a new way of exploring the structure of the Universe.We also examine the mathematical structure on which the Dirac equation rests beyond the usual dimension and signature. This reveals a rich internal symmetry and gives rise to a particularly aesthetic diagrammatic representation. Abstract Probing the Universe with a Relativistic Light Sail or Einstein-Dirac FermionsHumanity's profound curiosity about the cosmos is both undeniable and fundamental. To demystify the Universe, humankind is compelled to develop both direct and indirect probing strategies: direct exploration through physical visits using probes, and indirect exploration by observing cosmic electromagnetic field, gravitational waves and particles such as fermions.Building on these two strategies, this thesis proposes two distinct approaches to probing the Universe. In the first approach, we present a relativistic kinematic and dynamic model of light sails with arbitrary reflectivity and absorptance, undergoing non-rectilinear motion as a method of interstellar exploration. The problem involves solving for the trajectory of the sail in a 4-dimensional Minkowski spacetime manifold. By detailed computation, we derive the worldline of the sail in the laser's frame in the sail's proper time.The second approach applies the Two-State Vector Formalism and weak measurements to a spatially homogeneous and isotropic cosmological framework. Coupling Dirac spinors with classical gravity, we compute weak values of the energy-momentum tensor, the Z-component of spin, and pure states. Extending the work of Finster and Hainzl on Einstein-Dirac cosmology, we demonstrate that the Universe's accelerated expansion can be interpreted as a consequence of post-selection. We also show that weak measurements can amplify signals with simpler equipment by carefully selecting initial and final state vectors. This process also reveals geometric properties of the spacelike three-manifold of the Cosmos, opening new way on probing the structure of the Universe.We explore also the mathematical framework underlying the Dirac equation beyond the standard dimension and signature. This enterprise reveals its symmetrically rich properties and aesthetic diagrammatic representation.

A drink will be organized following the lecture.This lecture is proposed by "Kàp to UNIVERSEH", the kot-free space popularization project of the University of Namur, and Local Student Club of UNIVERSEH.When: Wednesday, February 26, 2025 at 7pmWhere: Faculty of Sciences - Auditorium S01Free I want to register

Practical info Date: Wednesday, March 12, 2025Location: PA01, entrance will be via the Faculty of Science lobby6:45pm: Doors open7:15pm: Show startsPrice and ticket sales: €5 pre-sale / €7 on the daySales: At lunchtime throughout the week of March 3 in the college hall!Payment: We prefer cash, but also accept payment by QR code or bank transfer. Read more

The IPCC warns of the growing impact of global warming on water, with more frequent droughts and floods threatening global supplies. By 2050, 42% of river basins will be severely affected, and flood damage could quadruple in the event of 4°C warming. Although they bear little responsibility, the most vulnerable populations suffer the worst consequences. In Wallonia, recent climatic disasters and water pollution illustrate the stakes. To raise public awareness, an event is being organized in Charleroi with debates and screenings.Program17:00 | Introductory session Head of UNESCO Belgium Mr Aurélien Dumont, Secretariat of UNESCO's Intergovernmental Hydrological Programme, World Water Situation17:40 | Screening of the film "H2O, water, life and us: the Emergency"18:30 | Break18:45 | Lectures and debate Prof. Dr. Marnik Vanclooster (U.K.). Marnik Vanclooster (UCLouvain), "Situation en Wallonnie" Prof. Alfred Bernard (UCLouvain), "Normes et toxicologie" Debate Moderated by Prof. Karim ZouaouiBouin (UCLouvain). Karim ZouaouiBoudjeltia (ULB), with the participation of Aurélien Dumont, Marnik Vanclooster, Alfred Bernard.20:30 | Cocktail dinnerGRATULAR : Registration required: f.amer@wbi.beThe members of the "exact and natural sciences" Sub-CommissionBernard Feltz (UCLouvain, Chairman), Bertrand Hespel (UNamur), Marie-Geneviève Pinsart (ULB, CIGB), René Rezsohazy (UCLouvain), Frédéric Rychter (Secrétaire général), Olivier Sartenaer (UNamur), Didier Serteyn (ULiège), Anne Staquet (UMons), Marnik Vanclooster (UCLouvain), Karim Zouaoui Boudjeltia (ULB)

The biodiversity crisis is not only destroying nature: it also threatens our societies, our well-being, and our survival. Based on scientific assessments and findings from IPBES, this Francqui Chair explores our toxic relationship with nature, the global failure to protect it, and the multiple values of living organisms. We will examine ways to recognize these values, repair our relationship, and bring about the transformative change that is needed.Keen to put the protection of ecosystems back at the center of public debate, UNamur is organizing a second Francqui Chair in Law this academic year with Professor Delphine Misonne on a related theme: "Need for the environment, need for law?"Free event upon registration.  More information and full program I'm signing up

The biodiversity crisis is not only destroying nature: it also threatens our societies, our well-being, and our survival. Based on scientific assessments and findings from IPBES, this Francqui Chair explores our toxic relationship with nature, the global failure to protect it, and the multiple values of living organisms. We will examine ways to recognize these values, repair our relationship, and bring about the transformative change that is needed.Keen to put the protection of ecosystems back at the center of public debate, UNamur is organizing a second Francqui Chair in Law this academic year with Professor Delphine Misonne on a related theme: "Need for the environment, need for law?"Free event upon registration.  More information and full program I'm signing up

The biodiversity crisis is not only destroying nature: it also threatens our societies, our well-being, and our survival. Based on scientific assessments and findings from IPBES, this Francqui Chair explores our toxic relationship with nature, the global failure to protect it, and the multiple values of living organisms. We will examine ways to recognize these values, repair our relationship, and bring about the transformative change that is needed.Keen to put the protection of ecosystems back at the center of public debate, UNamur is organizing a second Francqui Chair in Law this academic year with Professor Delphine Misonne on a related theme: "Need for the environment, need for law?"Free event upon registration.  More information and full program I'm signing up

The biodiversity crisis is not only destroying nature: it also threatens our societies, our well-being, and our survival. Based on scientific assessments and findings from IPBES, this Francqui Chair explores our toxic relationship with nature, the global failure to protect it, and the multiple values of living organisms. We will examine ways to recognize these values, repair our relationship, and bring about the transformative change that is needed.Keen to put the protection of ecosystems back at the center of public debate, UNamur is organizing a second Francqui Chair in Law this academic year with Professor Delphine Misonne on a related theme: "Need for the environment, need for law?"Free event upon registration.  More information and full program I'm signing up

JuryProf. Eli THORÉ (UNamur), PresidentProf. Patrick KESTEMONT (UNamur), SecretaryProf. Ranjàna RANDRIANARIVO (Université d'Antananarivo)Dr. Valérie CORNET (UNamur)Dr. Omayma MISSAWI (UNamur)Prof. Catherine MOUNEYRAC (Université Catholique de l'Ouest)Prof. Gauthier EPPE (ULiège)SummaryThe widespread production and use of plastics have led to their continuous release into the environment. Microplastics (MPs) are now ubiquitous in aquatic ecosystems, where their bioavailability to organisms and potential entry into the food web raise serious environmental and public health concerns. Substantial progress has been made in understanding MP toxicity, and their hazardous potential is now widely acknowledged. However, MP toxicity studies remain complex, as multiple particle characteristics, such as size, shape, polymer type, and sorbed contaminants might influence both bioavailabilityTo bridge this gap, the present thesis adopted a dual, complementary approach: (i) characterizing the environmental occurrence and bioavailability of MPs, and (ii) assessing the ecological relevance of using environmentally derived MPs in in vivo toxicity experiments.Overall, this thesis provides insights into the reproductive and transgenerational effects of environmentally relevant MPs while underscoring the importance of considering particle-pollutant interactions. By combining in situ field data with in vivo laboratory experiments, it demonstrates that the use of environmentally derived MPs represents a more realistic and ecologically meaningful approach to hazard characterization. Further studies should be carried out in this same perspective to generate robust, exploitable data and contribute to establishing a comprehensive MP risk characterization.

JuryProf. Nicolas DENDONCKER (UNamur), PresidentProf. Sabine HENRY (UNamur), SecretaryDr. Sébastien DUJARDIN (UNamur)Prof. Pierre OZER (ULiège)Prof. Emmanuel TWARABAMENYE (University of Rwanda)Prof. Caroline MICHELLIER (MRAC and UCLouvain)AbstractThis research investigates community vulnerability to landslides and floods in Northwestern Rwanda, hazards that frequently interact to produce compound disasters. The research focused on understanding the institutional, social, and structural factors that shape vulnerability and adaptive capacity in this disaster-prone region. Using a mixed-methods approach at local-scale, including institutional analysis, household surveys (n = 904), and field observations, the research highlights how vulnerability is shaped by socio-economic conditions, weak institutional coordination, and limited adaptive capacity. A Contextualized Vulnerability Index (CoVI) was developed to map vulnerability patterns, revealing particularly high vulnerability in landslide-prone and dual-hazard zones. The analysis of adaptive capacity showed that while awareness of hazards is high due to lived experiences, financial constraints, and limited technical knowledge hinder communities' ability to adapt effectively. The study contributes to the literature on social vulnerability and disaster risk reduction by emphasizing the importance of locally grounded, evidence-based strategies to strengthen community resilience in hazard-prone regions.

JuryProf. Régis HALLEZ (UNamur), PresidentProf. Jean-Yves MATROULE (UNamur), SecretaryDr. Rob VAN HOUDT (SCK CEN)Dr. Kristel MIJNENDONCKX (SCK CEN)Prof. Liselot DEWACHTER (UCLouvain)AbstractThe viable-but-nonculturable (VBNC) state is a type of bacterial dormancy triggered by sublethal stress, where cells remain intact but lose the ability to grow on standard media. This poses challenges for microbial monitoring and public health, as VBNC cells can evade detection and might regain virulence upon resuscitation. Copper compounds are explored as antimicrobial agents, however sublethal Cu concentrations were shown to induce the VBNC state in certain bacteria. This thesis investigates the Cu-induced VBNC state in Cupriavidus metallidurans, a metal-resistant betaproteobacterium, and examines the involvement of its Cu resistance determinants (CRDs). While resuscitation is usually mediated by external factors, we aimed to uncover intrinsic processes that enable spontaneous resuscitation, a rare phenotype lacking mechanistic understanding. Proteomic analysis revealed that expression of CRDs, among others, correlated with mitigated dormancy. Time-resolved profiling showed that VBNC cells exhibit highly dynamic proteomes: VBNC entry involved oxidative stress response, and resuscitation correlated with metabolic reconstitution and the strong induction of periplasmic CRDs. Temporal clustering corroborated the explored proteomic modifications. Through mutational studies we identified the plasmid-encoded copAB system as the minimal resuscitation factor, where integrity of the CopA methionine-rich domain proved critical. ICP-MS analysis indicated that detoxification relies on Cu sequestration rather than export. Altogether, this work uncovers key intrinsic factors and proposes a mechanistic basis for spontaneous resuscitation from the Cu-induced VBNC state in C. metallidurans. These insights refine our understanding of the VBNC state as a dynamic survival strategy and of bacterial Cu resistance.