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Characterization of trehalase from Acyrthosiphon pisum for the design of new insecticides SummaryAphids are major pests in agriculture, causing direct damage to plants and acting as vectors for phytopathogenic viruses. Conventional insecticides are widely used to control them, but their toxicity and efficacy pose problems in terms of the environment, human health and the emergence of resistance to these compounds. New alternatives are therefore needed, such as biological control using predators or parasitoids. However, these methods are not always economically viable on a large scale. As part of this thesis, another approach is being explored which involves developing new insecticides targeting the biochemical functions of aphids.The project aims to discover new inhibitors of trehalase, an enzyme essential for insect energy metabolism. Inhibition of this enzyme could disrupt vital insect functions without affecting mammals. This research involved several stages: the purification and complete characterization of trehalase from Acyrthosiphon pisum (the model for this study), the in vivo, in vitro and in silico analysis of commercial inhibitors on this enzyme, before moving on to the search for new inhibitors. Two points of integrated insect management were explored, biological and chemical control.The biological side saw the study of a strain of Streptomyces naturally producing trehalase-inhibiting metabolites, notably validamycin A, a molecule recognized in the literature as one of the best inhibitors, but not applicable as an insecticide. Other molecules appear to have interesting features, but we have not been able to isolate and characterize them.The chemical side has enabled us to create a pharmacophore hypothesis based on experimental results on molecules obtained by virtual screening. Although these molecules are not usable as insecticides as they stand, this hypothesis provides a better understanding of trehalase inhibitors in general and can be used to refine future analyses. JuryProf. Jean-Yves MATROULE (UNamur), presidentDr Catherine MICHAUX (UNamur), promoter and secretaryProf. Frédéric FRANCIS (ULiège), co-promoterProf. André MATAGNE (ULiège)Dr Rudy CAPARROS (ULiège)Dr Morgan HANS (Biocidal)

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.

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. 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.

With oral and poster presentations by ILEE affiliates. Students and young researchers are particularly invited to present their research and practice their presentation skills in English. The day is also important for ILEE members as it enables them to keep abreast of ongoing projects in different disciplines and to foster collaboration.At the end of the day, the annual general meeting of all members will take place with a summary of the past year's activities and achievements.We are honored to announce that Arnaud Péters, PhD in history and founder of sites_H, will be the keynote speaker!

His long-term collaboration with Dr. Aniruddha Chatterjee recently resulted in the first collaborative framework agreement between the University of Otago and UNamur, as well as an international Erasmus+ (EU) credit mobility funding this scientific mission. Frédéric Silvestre deepened his understanding of the advanced DNA methylation techniques employed by Dr. Chatterjee's team, including their bioinformatics workflows and innovative approach to epigenetic editing. He has given several seminars presenting LEAP's research on mangrove rivulus and turquoise molefish. He also presented at the Australasian Epigenetic Alliance conference and had the opportunity to explore potential new collaborations with other departments, including zoology, sustainable development, chemistry and marine sciences.

Quentin Willot (Biology) has just joined URBE for a two-year post-doctoral position (Marie Sklodowska-Curie Action, supervisor: Alice Dennis) on a project called ChillAnts. This project focuses on the study of adaptation to extreme temperatures in holarctic (trans-Beringian) ant species, from a physiological, ecological and evolutionary point of view. Quentin will present a more technical aspect of his work (Thermal Death Time Curve Modelling).

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!The seminar is open to external people too, no need to register. More info

Deadlines Opening of abstract submissions and registrations: September 15, 2025Deadline to submit indicative title and summary: November 30, 2025Deadline for final abstract submissions: May 1, 2026Early bird registration deadline: March 1, 2026 More information on the website

Presentations Romain Deleu (Geology): Hydrodynamics of solute transport in karst conduits: assessment by multi-point dye tracing and numerical modellingJustine Bélik (Biology): Can DNA methylation predict the age of a self-fertilizing vertebrate species?

JuryProf. Nicolas DENDONCKER (UNamur), ChairProf. Sabine HENRY (UNamur), SecretaryProf. Frédéric SILVESTRE (UNamur)Dr. Sébastien DUJARDIN (UNamur)Prof. Kara PELLOWE (Stockholm University)Prof. Romain GLELE KAKAI (University of Abomey Calavi)Prof. Patrick KESTEMONT (UNamur)Prof. Eli THORE (UNamur)AbstractMangroves play an important role in environmental conservation and livelihood provision yet remain one of the most threatened ecosystems on earth. This doctoral study assesses pathways to enhance coastal sustainability in the Anthropocene, by promoting the sustainable use of mangroves and strengthening their social-ecological resilience through an interdisciplinary approach. The thesis is structured into four specific objectives: assessing the role of traditional beliefs and local deities in promoting the sustainable use of mangroves, analyzing the synergies between legal frameworks and traditional beliefs in enhancing the social-ecological resilience of mangroves, developing a novel interdisciplinary framework to evaluate the social-ecological resilience of mangroves, and operationalizing the proposed framework in Benin's mangroves, West Africa.  We collected field data using ethnobiological surveys, drone image analysis and document review, in-depth interviews, focus group discussions, plant and fish inventories across three coastal communities in Benin. The study draws insights from the seven principles of resilience to analyze mangrove sustainability. The interdisciplinary methodology of this study links plant biology, fisheries sciences, and human geography to analyze mangroves as complex social-ecological systems. Findings of the thesis show that traditional beliefs and local deities play a significant role in regulating the use of mangrove resources, while the overlapping of formal and informal institutions offer opportunities to enhance their social-ecological resilience. The novel proposed framework called Mangrove Social Ecological Resilience Appraisal (MaSERA) outlines variables and indicators tailored to mangroves to assess their social-ecological resilience. Its application in Benin highlights its potential in identifying factors that enable or erode mangrove resilience, for informed decision making. The study argues that promoting the sustainable use of mangroves and enhancing their social-ecological resilience represent dual imperatives for achieving coastal sustainability in the Anthropocene. It contributes to the growing body of knowledge on mangrove conservation and provides actionable insights for integrated coastal zone management.