Résultats de recherche

SynopsisOver recent years, the development of agent-based models has allowed researchers to advance their understanding of naturally occurring collective behaviours. Swarm robotics, a field studying the design of decentralised robot swarms, has emerged following the replication of some collective behaviours in artificial groups of robots. The first part of this thesis provides novel techniques for the aggregation of heterogeneous swarms. First, we enhance an existing controller for an aggregation problem on two sites through the use of informed robots. We show that our simplified approach offers a wider range of operating conditions and a greater flexibility. Second, we provide a new method for the aggregation of robot swarms with adaptive random walks. We separately study cue-based aggregation with a swarm of robots only sensing private information and neighbour-based aggregation with a swarm of robots sensing social information. We show that a trade-off can be obtained with a heterogeneous swarm composed of the two robot types, forming a dense cluster near the minimum of an environmental cue. Private and social information also play a key role in the evolution of biological processes inside animal groups. Dispersal, the movement of an animal from site of birth to site of reproduction, is strongly affected by the acquisition and the use of information. Since experimental research is often difficult to conduct while accounting for multiple information sources and environmental variability, the use of agent-based models offer an opportunity to study the evolution of dispersal and its associated costs linked to private and social information in a controlled setting. The second part of this thesis provides an agent-based model of dispersal including the acquisition of information and its associated costs. Throughout three case studies, we observe the evolution of genes linked to the acquisition of information and the obtained dispersal strategies in different scenarios. Jury members Prof. Wim Vanhoof, Président, Université de Namur, BelgiqueProf. Elio Tuci, Secrétaire, Université de Namur, BelgiqueProf. Timoteo Carletti, Membre interne, Université de Namur, Belgique Prof. Eliseo Ferrante, Membre externe, Vrije Universiteit Amsterdam, Pays-BasProf. Mauro Birattari, Membre externe, ULB, Belgique Prof. Andreagiovanni Reina, Membre externe, Universität Konstanz, Allemagne  La défense sera suivie d'un drink. Je m'inscris

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)

La deadline d'inscription et de soumission pour les abstracts : 20 août 2025.  Plus d'infos sur le site internet de l'Institut NARILIS