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A team of microbiology researchers from UNamur has just published in the journal Nature Communications. The work focuses on the Brucella bacterium that causes Brucellosis, a disease that infects livestock and can be transmitted to humans. This research aims to better understand the molecular mechanisms of the bacterium's growth in order to better combat it.

With its expertise in the field of geology and biodiversity conservation, the UNamur is one of the partners of the new Entre-Sambre-et-Meuse National Park designated by the Walloon Government. Alongside the other actors and promoters of the project, the UNamur will make its knowledge and experience available to enhance and preserve this exceptional natural heritage!

When a tumour develops in an organism, it is very common for the cancer cells to leave the tumour and move to another organ where they proliferate, creating what are known as metastases. This process is an important factor in mortality, as it means that the disease worsens. Hence the interest in better understanding what happens during this phenomenon. This is what the multidisciplinary team of Carine Michiels, researcher at the NARILIS Institute of UNamur, and Davide Bonifazi, researcher at the University of Vienna, did in the framework of the PACMAN research project financed by the FNRS. The results of this study are published in the journal Neoplasia.

EMBO Courses and Workshops are selected for their excellent scientific quality and timelines, provision of good networking activities for all participants and speaker gender diversity (at least 40% of speakers must be from the underrepresented gender). Organisers are encouraged to implement measures to make the meeting environmentally more sustainable.Upon registration - More info and registration on the EMBO website.

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 efficacy 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), PresidentProf. Stéphane LUCAS (UNamur), SecretaryProf. Carine MICHIELS (UNamur)Dr Sébastien PENNINCKX (Hôpital Universitaire de Bruxelles)Prof. Cristian FERNANDEZ (University of Bern)Dr Rudi LABARBE (IBA)

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)

At the end of January 2023, the Metropolitan Museum of Art (New York) returned a real treasure to Belgium: a medieval charter bearing the seal of the Count of Flanders Philippe d'Alsace, formerly kept in the abbey of Messines (West Flanders), which had disappeared at the beginning of the First World War. A look back at the tribulations of this archival document, the restitution of which is the result of a fruitful collaboration between the PraME Centre of UNamur, the General Archives of the Kingdom and the Ministry of Foreign Affairs.

The Department of Art History and Archaeology of UNamur is participating for the first time in an experimental archaeology project, within the framework of a doctoral thesis on the production of glass in the Roman period. Conducted in partnership with Malagne, the Rochefort archaeopark, the Specularia project aims to gain a better understanding of the reality of the gestures and techniques of Gallo-Roman craftsmen and to scientifically validate hypotheses that are still debated today. To carry out this experiment, the Department of Art History and Archaeology is launching its first participatory funding.

This is a first at the UNamur: a team of archaeologists will soon be testing an experimental protocol to reproduce the process of shaping glass in Roman times. Entitled Specularia (Latin for "glass"), this project has the support of several associations and companies, including AGC Glass Europe.

The documentary produced as part of the experimental archaeology research project, "Specularia", wins an award at an American festival, organized by the University of Pittsburgh and the University of South Carolina!

Angélique Aristondo, a C2W post-doctoral fellow at UNamur, has distinguished herself by winning the second 2023 Gender and Health Research Award from the ARES Women and Science Committee. Her research project focuses on violence against women in Senegal.