naXys Newsletter – September 2022


  • Observer and control design for cell population models of yeast fermentation processes, Pascal Jerono (UNamur), September 22, 13:00 – 14:00, Room S08
  • Partial tail correlation for extremes, Jeongjin Lee (UNamur), October 13, 13:00 – 14:00, Room S08
  • Recent topics in complexity for nonconvex optimization problems, Philippe Toint (UNamur), October 27, 13:00 – 14:00, Room S08

Abstracts can be found on our website:



Last May, naXys researchers gathered for the annual Research Day. Many PhD students and post-docs presented their work in 3 minute flash talks, the new AI Research Pole was described by naXys researcher Elio Tuci, and Jérôme Mallargé, ADRE ICT scientific advisor, gave an overview of the funding opportunities for researchers and students. naXys members also discussed the future directions of the Institute and looked for new keywords accurately describing the interdisciplinary nature of the naXys research poles. The naXys Research Day 2022 will be organized at the end of this year. More information will follow.


A recent work on ecology involving naXys researcher Frederik de Laender was published in the prestigious journal  Nature Communications.

Abstract: Species diversity is typically thought to promote functional diversity. More species of plants would provide more varied crops, more species of predator cats would provide more varied camouflage patterns, etc. While this positive relationship intuitive and supported by empirical data, we show that it vanishes when we take into account the evolution of the functional characteristics of populations (their ’traits’). We use theoretical models and data from Galápagos land snail communities to show how eco-evolutionary processes can force species to evolve narrower trait breadths in more species-rich communities to avoid competition. Specifically, individuals within populations become more ‘alike’ in order to avoid too much interaction with individuals from other species. This ’narrowing down’ effect is so strong that functionally diversity can turn out to be lower when more species are present, thus creating a negative relationship between species and functional diversity.

Reference: Barbás G., Parent C., Kraemer A., Van de Perre F., De Laender F., The evolution of trait variance creates a tension between species diversity and functional diversity, Nat Comm. 13, 2521 (2022). Link to the paper.


Pascal Jerono joined naXys in July 2022 for a short stay of a few months, after a PhD at Christian-Albrechts-Universität in Kiel (Germany). His main scientific field of expertise is the observer and tracking control design for cell population models of yeast fermentation processes, which are described by mathematical equations that model the cell population dynamics. This project at naXys is focused on the observability property of cell population balance models with biomass measurements within the framework of indistinguishable trajectories, with the perspective of designing efficient observers for such processes. This research is a joint work with the University of Kiel and UMons. This is another example of the interdisciplinary nature of the research conducted in naXys, as it brings nicely together the naXys ROBUST & BIO research poles.

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