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UID:0-768@lptms.universite-paris-saclay.fr
DTSTART;TZID=Europe/Paris:20210511T110000
DTEND;TZID=Europe/Paris:20210511T120000
DTSTAMP:20210428T190406Z
URL:http://www.lptms.universite-paris-saclay.fr/seminars/seminaire-du-lptm
 s-antoine-fruleux/
SUMMARY:Séminaire du LPTMS : Antoine Fruleux (Ecole Polytechnique) - LPTMS
  (100% online seminar) - 11 Mai 21 11:00
DESCRIPTION:Fluctuations in biological tissues\nAntoine Fruleux (École Pol
 ytechnique\, LadHyX)\nBiophysics — Modeling &amp\; Data analysis — Mor
 phogenesis\n\nOnline seminar --- Zoom Meeting ID: 991 9867 1888 -- Passcod
 e: ask L. Mazza and D. Petrov --\n\n[caption id="" align="aligncenter" wid
 th="640"] Figure 1: Cell growth is heterogeneous in space and time. Exampl
 e of a sepal (green organ that protects a flower before it opens) from the
  model plant Arabidopsis thaliana. The colour scale corresponds to growth 
 rates (high in red\, low in blue).[/caption]\n\nThe two hands of most huma
 ns almost superimpose. Similarly\, flowers of an individual plant have\nsi
 milar shapes and sizes. This is in striking contrast with growth and defor
 mation of cells during\norgan morphogenesis\, which feature considerable v
 ariations in space and in time\, raising the question\nof how organs and o
 rganisms reach well-defined size and shape. In order to link cell and orga
 n scales\,\nI built a stochastic hydrodynamic model of growing tissue with
  fibre-like structural elements that may\naccount for the plant cell wall 
 or animal cytoskeleton or extracellular matrix [1]. The model gave two\nim
 portant predictions. First\, fluctuations occurring at cellular scale exhi
 bit long-range correlations.\nSecond\, the response of fibres to growth-in
 duced mechanical stress may enhance or buffer cellular\nvariability of gro
 wth\, making it possible to modulate the robustness of morphogenesis.\nI w
 ill present in more details these results as well as a mathematical tool I
  defined to analyze signal\nin tissues: the Cellular Fourier Transform (CF
 T) [2]. It is suited to those signals which can only be\ndefined at a cell
 ular scale\, or which are smoothed out of their sub-cellular variations\, 
 and it allows\nto overcome the constrains met when studying biological tis
 sue\, foams\, granular materials or other\ngeometrically disordered materi
 als. I will introduce the method and explain how it reveals the physical\n
 mechanisms setting spatial heterogeneity in growing tissues.\nReferences\n
 [1] Antoine Fruleux and Arezki Boudaoud. Modulation of tissue growth heter
 ogeneity by responses\nto mechanical stress. Proceedings of the National A
 cademy of Sciences\, 116(6):1940–1945\, 2019.\n[2] Antoine Fruleux and A
 rezki Boudaoud. Cellular fourier analysis for geometrically disordered\nma
 terials. Physical Review Research\, 3(2):023036\, 2021.
CATEGORIES:seminars
LOCATION:LPTMS (100% online seminar)\, LPTMS - Bâtiment Pascal n° 530 rue
  André Rivière - Université Paris-Saclay\, Orsay\, 91405\, France
X-APPLE-STRUCTURED-LOCATION;VALUE=URI;X-ADDRESS=LPTMS - Bâtiment Pascal n
 ° 530 rue André Rivière - Université Paris-Saclay\, Orsay\, 91405\, Fr
 ance;X-APPLE-RADIUS=100;X-TITLE=LPTMS (100% online seminar):geo:0,0
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