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We are interested in understanding fundamental physics and the use of light technologies. We stand at the crossroads of analytical developments in classical and quantum electrodynamics and an intensively developed toolbox in numerical simulation for photonic systems. Our aim is to stay as close as possible to experimental fabrication and characterization.

On the occasion of the International Day of Women and Girls in Science proclaimed on February 11 by the United Nations General Assembly, and as part of the European alliance European Space University for Earth and Humanity (UNIVERSEH) focusing on the theme of space, discover the testimonies of four women scientists from UNamur working on astronomical themes.

Jury Prof. Benoît MUYLKENS (URVI, Université de Namur), PresidentProf. Carine MICHIELS (URBC, Université de Namur), SecretaryProf. Xavier DE BOLLE (URBC, Université de Namur)Prof. René REZSOHAZY (LIBST, Université catholique de Louvain)Prof. Florian STEINER (Dept. of Molecular and Cellular Biology, Université de Genève)Prof. Germano CECERE (Department of developmental and Stem Cell Biology, Institut Pasteur) Summary In animals, germ cells are often distinguished from somatic lineages at the earliest stages of embryogenesis. In some organisms, germ blastomeres appear to enter a state of transcriptional quiescence. For example, in the worm Caenorhabditis elegans, transcription is activated in somatic blastomeres as early as the 4-cell stage, whereas it is not initiated in germline blastomeres until the 100-cell stage. This transcriptional repression in germ blastomeres has been attributed to the PIE-1 protein, specifically localized in these cells from the first embryonic division. PIE-1 is thought to inhibit the activity of CDK-9, a cyclin-dependent kinase previously considered essential for the phosphorylation of serine 2 (CTD-Ser2) of the C-terminal domain (CTD) of RNA polymerase II and for transcription elongation. However, recent studies, showing that embryogenesis proceeds normally in a mutant strain expressing a CTD in which serines 2 is replaced by an alanine (CTD-S2A) and identifying CDK-12 as the main kinase phosphorylating CTD-Ser2, call this model into question.To study the transcriptome of germline blastomeres in the worm C. elegans, an approach combining cell sorting and RNA sequencing (RNA-seq) was developed. Pilot analyses validated this method on a wild-type strain, enabling its use on a strain in which PIE-1 can be specifically degraded using the Auxin-Inducible Degron (AID) system. This made it possible to examine the effect of PIE-1 depletion on the transcriptome of germline blastomeres revealing that in its absence, germline blastomeres adopt a transcriptional profile close to that of somatic blastomeres, confirming the fundamental role of PIE-1 in preserving germline identity during embryogenesis. In parallel, the fission yeast Schizosaccharomyces pombe was used to analyze the consequences of PIE-1 expression in a heterologous organism. The results showed that PIE-1 by localizing near transcription termination sites induces further transcription by RNA polymerase II beyond the termination site, leading to transcription of intergenic regions. These observations led to the hypothesis that in C. elegans,within germinal blastomeres, PIE-1 might regulate alternative polyadenylation in 3' untranslated regions, producing longer RNA isoforms susceptible to degradation. In the absence of PIE-1, shorter isoforms could be generated, allowing accumulation of somatic transcripts and potentially degradation of maternal mRNAs via somatic protein translation. Although further investigations are required in C. elegans to validate this hypothesis, it provides an innovative conceptual framework for understanding the role of PIE-1, independent of CTD-Ser2 phosphorylation.

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.

As part of their training in archaeology, students at the University of Namur experience a unique immersion in their future profession thanks to workcamps. This program, developed by the Department of Archaeology and Art Sciences, closely combines field experience and academic learning.

Two researchers at the Institut du Langage, du Texte et de la Transmédialité (NaLTT) have just been awarded funding from the F.R.S - FNRS following calls whose results were published in December 2024.Composed of researchers in linguistics and literature, the NaLTT Institute constitutes an interdisciplinary space for diachronic and synchronic research into verbal and multimodal communicative practices that manifest themselves in, are shaped and/or regulated by culture and society.

Program 5-6pm: Student read-aloud6-7:30pm: Lecture by Julia Kerninon7:30pm-9pm: DrinkConference and performance aimed at students but open to all, interns and externs. Free but reservation required (aurelie.sinte@unamur.be)

Two researchers from the Institut Patrimoines, Transmissions, Héritages (PaTHs) have just been awarded funding from the F.R.S - FNRS following calls whose results were published in December 2024. The PaTHs institute is a federation of research centers and groups that have sprung up in and around the Faculty of Philosophy and Letters. The institute is distinguished by its emphasis on critical analysis of the "traces" of the past (written, material, monumental, landscape, visual, sound...), to the point of placing the "trace" itself at the heart of scientific questioning.

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

Research seminar co-organized by Louis Carré and Sabina Tortorella as part of the activities of the Esphin Institute, the Department of Philosophy, and the Arcadie Center as well as the Marie Skłodowska-Curie SOCIAL project This seminar sets out to explore contemporary uses of Hegel's practical thought as well as to question its relevance and legacy. Themes central to recent philosophical debates, such as globalization, race, feminism and the Anthropocene, as well as contemporary challenges facing philosophical reflection - such as social justice and ecological transition, state sovereignty in the face of international markets and the emergence of supranational subjects, or the crisis of democracy in the face of the rise of populism and the return of war - may call for a mobilization of Hegelian thought. The aim of this seminar is not necessarily to propose a strictly historical-philosophical reading of Hegelian thought, but rather to seek to take Hegel beyond Hegel himself, by engaging in a reflection on problematics that find their first formulation in him, but that have developed far beyond his conceptual framework, or by questioning his concepts from perspectives that do not necessarily lay claim to Hegelianism. The aim of this approach is to bring Hegel's thought into dialogue with other philosophical traditions and currents of political philosophy, in order to question its ability to shed light on some of the major issues of our time. By questioning its topicality and limitations, this seminar aims to examine what practical Hegelian philosophy can still offer us today, and how it enables us to question our own problems from a renewed angle. While it is unlikely to provide ready-made solutions, it can perhaps help us to ask the right questions and think differently about the tensions of our time.Chiara Magni (Università degli Studi Roma Tre) will speak on the theme: "What rights for the accused and the convicted? Criminal prosecution and human dignity in the light of Hegel's practical philosophy"Link to attend the online seminar Contact: sabina.tortorella@unamur.beThis project has received funding from the European Union's Horizon Europe research and innovation programme under the Marie Skłodowska-Curie grant agreement No 101150961.

Beautiful victory for Margaux Mignolet, a researcher at the Faculty of Medicine's Unité de Recherche en Physiologie Moléculaire (URPhyM), who wins 1st prize in the Belgian inter-university final of the Ma thèse en 180 secondes (MT180) competition. Her research? To better understand the mechanisms of antibodies active in cases of long COVID. The second prize in this national competition was also won by a candidate from Namur. It was Petra Manja, from the Unité de Recherche en biologie des micro-organismes (URBM), Department of Biology, Faculty of Science, and is pursuing a thesis aimed at understanding resistance mechanisms in the bacterium E. coli. Both are also researchers at the NARILIS Institute.