Seminars
Contact :
Hèléne Berthoumieux
Tel : +33 (0) 1 40 79 xx xx
Paddy Royall
Tel : +33 (0) 1 40 79 xx xx
Gulliver seminars take place on Mondays at 11:30 AM in the F304 room, and typically last one hour including questions. The seminars are in English, and the scientific topics are mainly those studied in the laboratory.
Gulliver Seminar : Maxime Deforet (LJP-Sorbonne)
Decoding crowding dynamics in monolayers of motile bacteria using DiSTnet2D, a novel method for segmentation and tracking
Bacterial populations provide a compelling experimental model for studying active matter. Most studies have focused on systems driven by cell divisions (growth of microcolonies and biofilms) and by cell motility and hydrodynamical interactions (emergence of flocking and "active turbulence"). Here, I will present a system of "dry" active matter with a motile bacterium : dense monolayers of Pseudomonas aeruginosa.
I will first present DiSTNet2D, a novel method for object segmentation and tracking that leverages temporal context. DiSTNet2D is based on a Deep Neural Network that takes multiple consecutive frames as input to simultaneously perform segmentation and tracking. DiSTNet2D is hosted within Bacmman, an ImageJ plugin, which allows for generating training datasets, training, running the computation, and exporting the results.
Using DiSTNet2D, we analyze extensive fields of bacterial monolayers, achieving 100% accuracy in our observations across three decades of time. Our findings reveal complex dynamics : the wide cell size distribution, resulting from ongoing division, forms an amorphous structure that hampers crystallization. Additionally, we observe the spontaneous emergence of dynamic spatial heterogeneities and, at higher densities, characteristics indicative of a glass transition (specifically, a kinetic slowdown and the divergence of correlation times), which occur independently of individual cell motility patterns.
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Recent seminars (6)
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Gulliver seminar : Matthew Turner (Warwick University, UK)
Lundi 13 mai de 11h30 à 12h30 - C162
Collective motion & environmental path entropy
We discuss a “bottom up” model for collective motion. This involves moving agents that re-orientate so as to maximise a measure of the entropy of their environment in the future. We discuss why such principles might confer fitness on rather general grounds. We then discuss the dynamics that arise from them that lead (...) -
Gulliver Seminar : Haim Diamant (Tel Aviv University)
Lundi 29 avril de 11h30 à 12h30 - C162
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Gulliver Seminar : Séverine Atis (CNRS, Poitiers)
Lundi 8 avril de 11h30 à 12h30 - C162
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Gulliver Seminar : Séverine Atis (CNRS, Poitiers)
Lundi 8 avril de 11h30 à 12h30 - C162
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Gulliver Seminar : Emilie Verneuil (ESPCI)
Lundi 25 mars de 11h30 à 12h30 - C162
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Gulliver Seminar : Emilie Verneuil (ESPCI)
Lundi 25 mars de 11h30 à 12h30 - C162
The audience is often heterogeneous - because of the wide range of scientific topics covered in the lab - so planning a talk for a broader audience would be preferred. The seminar is in English, and speakers are thus invited to prepare their slides in English.
The seminar starts at 11:30 AM. The speaker is asked to arrive in the lab at least 15 minutes in advance to set up their computer. The talks last typically 45 minutes, and are followed by a discussion time.