The world is a complex and dynamic place. Earth takes part in an intricate dance with the moon, surrounding planets, our sun, other stars and entire galaxies. All interact with one another determining our position in the universe. On a much smaller scale, humans consist of trillions of cells that work together to let us walk, run, and think. Each such single living cell is driven by the interaction of about a trillion non-living molecules. Life at all scales is complex, dynamic, and difficult to understand. All these examples, however, have in common that they obey the basic laws of physics. Although we can apply those laws to understand a small part of each system, many interacting parts can behave wildly different and unpredictable. By combining theory and experiment, our lab aims at understanding such system dynamics, studying living (Dynamics in Biology) and non-living (Dynamics in Physics) systems.

## News

#### Felix successfully defended his PhD

November 2021

Felix convincingly presented his PhD work entitled “Mathematical modeling of nuclei as pacemakers of cell cycle oscillations”. It was a wonderful day and evening, celebrating Felix's achievements of the last few years. We wish Felix all the best in his new position teaching at the university in Antwerp. As he won't be far away, we hope to still see you regularly here. Congratulations Dr. Nolet!

#### Jolan successfully defended his PhD

September 2021

In the context of a joint PhD with Prof. Verfaillie of the Stem Cell institute, Jolan presented his PhD work entitled “On the study of cellular proliferation and differentiation: From experiment to theory”. Many thanks to everyone in the jury, being Georg Halder, Hans Van Oosterwyck, Leo van Grunsven, and Julia Kamenz. Everyone agreed that Jolan did an excellent job and were particularly impressed with his to-the-point and in-depth knowledge of both experimental and theoretical work. Similarly impressed here Jolan!

#### A modular approach for modeling the cell cycle based on functional response curves

August 2021

Bistability plays an important role in many biochemical processes and typically emerges from complex interaction patterns such as positive and double negative feedback loops. Jolan and Jan explicitly incorporated a functional expression describing an S-shaped input-output curve in the model equations, without the need for considering the underlying biochemical events. Using such approach, we then constructed a cell cycle model consisting of multiple bistable switches, accounting for a number of known properties of the cell cycle. Nice work Jolan and Jan! Read more here in our PLoS Comp. Biol. paper.

#### Analytical approximations for the speed of pacemaker-generated waves

July 2021

In oscillatory media, waves can be generated by pacemaker regions which oscillate faster than their surroundings. Jan applied analytical tools (i.e. singular perturbation and phase reduction methods) to investigate the factors that determine the speed of these waves. These analytical estimates are compared to numerical simulations described in our previous work. Check out the paper in Phys. Rev. E. Good stuff Jan!

#### How do nuclei control mitotic waves in an import-diffusion model?

July 2021

In this work, Felix extended the modeling work he did for our 2020 eLife paper in which we showed that nuclei control the spatial origin of mitotic waves. He analyzed a model where nuclei periodically import and export cell cycle regulators, leading to a redistribution of such regulator in the cytoplasm. We show that when the cell cycle period depends on the local concentration of regulators, the model exhibits mitotic waves. Congratulations Felix! Read more here.