Résultats de recherche

La crise de la biodiversité ne détruit pas seulement la nature : elle menace aussi nos sociétés, notre bien-être et notre survie. À partir des évaluations scientifiques et des constats de l’IPBES, cette Chaire Francqui explore notre relation toxique avec la nature, l’échec global de sa protection et les valeurs multiples du vivant. Nous examinerons les pistes pour reconnaître ces valeurs, réparer notre relation et réaliser le changement transformateur requis.Soucieuse de remettre la protection des écosystèmes au centre du débat public, l’UNamur organise cette année académique une seconde Chaire Francqui en droit avec la Professeure Delphine Misonne sur une thématique connexe "Besoin d'environnement, besoin de droit ?"Evènement gratuit sur inscription.La leçon sera suivie d’un drink local. Plus d'infos et programme complet Je m'inscris

Le mercure et l'Océan : leçons du passé et enjeux pour le futur Polluant hautement toxique, tristement connu depuis la catastrophe de Minamata au Japon dans les années 1950, le mercure s’accumule depuis la révolution industrielle dans les océans où il menace la faune marine et l'Homme. Sa surveillance et sa réduction constituent aujourd’hui un enjeu mondial, inscrit dans la Convention de Minamata signée par 147 pays.Cette leçon sera suivi d'un drink.Save the date!Plus d'infos ici bientôt... Je m'inscris

JuryProf. Eli THORÉ (UNamur), PrésidentProf. Patrick KESTEMONT (UNamur), SecrétaireProf. 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)RésuméThe 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), PrésidentProf. Sabine HENRY (UNamur), SecrétaireDr Sébastien DUJARDIN (UNamur)Prof. Pierre OZER (ULiège)Prof. Emmanuel TWARABAMENYE (Université du Rwanda)Prof. Caroline MICHELLIER (MRAC et 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), PrésidentProf. Jean-Yves MATROULE (UNamur), SecrétaireDr 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.

JuryDr Luca FUSARO (UNamur), PrésidentProf. Carmela APRILE (UNamur), SecrétaireProf. Francesco GIACALONE (Université de Palerme)Prof. Paolo PESCARMONA (Université de Groningen)Prof. Michelangelo GRUTTADAURIA (Université de Palerme)AbstractThis PhD research focused on the design, synthesis, and catalytic evaluation of novel materials based on metal phthalocyanines (MPCs) and imidazolium bromide salts. The initial materials were extensively characterized using a wide range of analytical, spectroscopic, and spectrometric techniques, including solid-state NMR, XPS, TEM, EDX, FT-IR, Raman, CHN analysis, ICP-OES, N₂ physisorption, and TGA. These systems showed remarkable performance in promoting the cycloaddition of CO₂ to epoxides to form cyclic carbonates. Building on these results, a new class of catalysts was developed by covalently anchoring metal phthalocyanines and imidazolium salts onto multi-walled carbon nanotubes (MWCNTs), yielding materials denoted as MPC@MWCNTs. This strategy enabled the creation of a versatile family of catalysts—prepared with different metal centers (Al, Mg, Fe, Ni, Co, Cu, Zn)—while maintaining a unified synthetic approach. The incorporation of MWCNTs was aimed at enhancing both catalytic activity and stability through synergistic support effects. The resulting MPC@MWCNTs were successfully applied in diverse catalytic contexts: CO₂ valorization into cyclic carbonates (Mg-, Fe-, Cu-, and Zn-based systems), nitro-reduction reactions to afford amines (Fe-based system), and electrocatalytic methanol oxidation for energy-related applications (Ni-based system). Overall, this work demonstrated the potential of MPC@MWCNT hybrid materials as robust, tunable, and multifunctional catalysts for sustainable chemical transformations. Assister à l'événement à distance (Teams)

Une conférence donnée en anglais par André Füzfa, Professeur au sein du Département de Mathématique de l'UNamur. Quand : Lundi 14 avril 2025 à 19hOù : Université de Namur - Faculté des sciences - Amphithéâtre S01GratuitEn anglaisPossibilité de rejoindre la conférence en ligne, le lien sera partagé quelques heures avant l'évènement. Retrouvez toutes les infos sur les comptes Facebook (Kapto.UNIVERSEH.) et Instagram (@kapto_universeh) du Kot-à-projet. Un drink sera organisé suite à la conférence.Cette conférence est proposée par "Kàp to UNIVERSEH", le projet sans kot de vulgarisation spatiale de l'Université de Namur, et Local Student Club d'UNIVERSEH. S'inscrire

2025 theme: Stress and emotions in animals The purpose of the symposium aligns with the missions of BCLAS to promote the replacement, reduction and refinement of laboratory animal use by driving reflection, sharing information, providing education and support to the scientific community, authorities and public, in order to lead to an ethical, responsible and qualitative research enabling further improvement in human & animal health.

Abstract Over the past two centuries, advances in healthcare have significantly extended life expectancy by reducing the impact of many diseases. As this progress continues, attention shifts toward more complex illnesses, with cancer emerging as the foremost challenge. Photodynamic therapy (PDT) is a light-activated cancer treatment approved in 1995 that offers a targeted approach by using photosensitizers (PSs) — compounds that, upon light activation, generate reactive singlet oxygen to selectively damage tumor tissue. However, current commercial PSs suffer from several drawbacks: ill-defined composition, poor accumulation in tumors and slow clearance, limited application depths, and insufficient fluorescence for diagnostic imaging. This thesis addresses these limitations by pursuing the development of efficient and partially fluorescent PSs that absorb strongly in the red to near-infrared (NIR) range. The first part of the work focuses on computational tools based on quantum chemistry, particularly density functional theory, to predict molecular properties relevant to PDT. These methods are benchmarked and refined to ensure accurate and efficient screening of candidate compounds. Additionally, a commonly used metric for quantifying charge transfer distance in excited states is reformulated to be independent of molecular symmetry, allowing broader and more robust applicability. In the second part, these tools guide the design of novel PSs. One strategy involves modifying pyrrolopyrrole aza-BODIPY dyes into donor–acceptor structures to enable singlet oxygen generation via spin–orbit charge transfer intersystem crossing (SOCT-ISC). Another approach focuses on a twisted BODIPY compound that achieves photosensitization by facilitating ISC through a distortion of the symmetry. This PS is tuned to absorb NIR light and, in some cases, leverage the SOCT-ISC mechanism. Overall, these efforts did not only yield promising PSs but also provided computational insights to accelerate future developments in the field. Le jury Prof. Guillaume BERIONNI (UNamur), PrésidentProf. Benoît CHAMPAGNE (UNamur), SecrétaireProf. Wouter MAES (UHasselt)Prof. Dirk VANDERZANDE (UHasselt)Prof. Anitha ETHIRAJAN (UHasselt)Prof. Yoann OLIVIER (UNamur)Prof. Wim DEHAEN (KULeuven)Prof. Anna PAINELLI (Universita di Parma)Prof. Mariangela DI DONATO (LENS)Prof. Jan COLPAERT (UHasselt)

Charting the DNA methylome landscape in cancer, chronic disease and phenotype Abstract: Our team has developed some of the first pipelines for genome-scale DNA methylation analysis. Our work has revealed aberrant methylation and expression patterns in several cancer types and revealed new mechanism of epigenetic regulation in cancer cells. We are now applying cutting-edge whole genome scale DNA methylation analysis in tissues as well as well as in cell free DNA (epigenetic liquid biopsy) and epigenetic editing platforms to investigate clinically relevant biomedical questions in cancer (for example, methylation map of colorectal, prostate, lung cancer and pancreatic cancer patients). Our work in epigenetic editing has implication in revealing causal function and new epigenetic regulation. In this talk, I will present the key findings from some of our works over the years and also elaborate on some recent and future directions in understanding the role of DNA methylation events in cancer metastasis, early detection, and treatment monitoring in solid cancers and also in chronic diseases and phenotype. More information on the ILEE website

High-Sensitivity Birefringence Mapping Using Near-Circularly Polarized Light I will describe several techniques for mapping a two-dimensional birefringence distribution, which can be classified according to the optical schemes and principles of work:Illumination geometry (transmitted light/reflected light)Image acquisition (sequential acquisition/simultaneous acquisition)Polarization control (electrically controlled variable retardance/mechanical rotation).This classification facilitates a comparative analysis of the capabilities and limitations in these methods for birefringence characterization. Polychromatic polarizing microscopy (PPM) provides unique capabilities to alternative methods. It leverages vector interference to generate vivid, full-spectrum colors at extremely low retardances, down to < 10 nm. PPM is a significant departure from conventional polarizing microscopes that rely on Newton interference, which requires retardances above 400 nm for color formation. Furthermore, PPM's color output directly reflects the orientation of the birefringent material, a feature absent in conventional microscopy where color is solely determined by retardance.Joint seminar of ILEE & NISM!Le séminaire est accessible à des personnes externes également, pas besoin de s'inscrire. Plus d'infos

Abstract Radiotherapy is a cornerstone of cancer treatment and is currently administered to approximately half of all cancer patients. However, the cytotoxic effects of ionizing radiation on normal tissues represent a major limitation, as they restrict the dose that can be safely delivered to patients and, consequently, reduce the likelihood of effective tumor control. In this context, delivering radiation at ultra-high dose rates (UHDR, > 40 Gy/s) is gaining increasing attention due to its potential to spare healthy tissues surrounding the tumor and to prevent radiation-induced side effects, as compared to conventional dose rates (CONV, on the order of Gy/min).The mechanism underlying this protective effect—termed the FLASH effect—remains elusive, driving intensive research to elucidate the biological processes triggered by this type of irradiation.In vitro models offer a valuable tool to support this research, allowing for the efficient screening of various beam parameters and biological responses in a time- and cost-effective manner. In this study, multicellular tumor spheroids and normal cells were exposed to proton irradiation at UHDR to evaluate its effectiveness in controlling tumor growth and its cytotoxic impact on healthy tissues, respectively.We report that UHDR and CONV irradiation induced a comparable growth delay in 3D tumor spheroids, suggesting similar efficacy in tumor control. In normal cells, both dose rates induced similar levels of senescence; however, UHDR irradiation led to lower apoptosis induction at clinically relevant doses and early time points post-irradiation.Taken together, these findings further highlight the potential of UHDR irradiation to modulate the response of normal tissues while maintaining comparable tumor control.JuryProf. Thomas BALLIGAND (UNamur), PrésidentProf. Stéphane LUCAS (UNamur), SecrétaireProf. Carine MICHIELS (UNamur)Dr Sébastien PENNINCKX (Hôpital Universitaire de Bruxelles)Prof. Cristian FERNANDEZ (Université de Bern)Dr Rudi LABARBE (IBA)