Matière molle et biophysique - Jean-François Joanny

Jean-François JoannyMatière molle et biophysiqueCollège de FranceAnnée 2024-2025Conférence - Mark Bowick - Nonabelian Topological DefectsMark BowickDeputy Director, Kavli Institute for Theoretical Physics, University of California Santa BarbaraMark Bowick est invité par l'assemblée du Collège de France sur proposition du professeur Jean-François Joanny, chaire Matière molle et biophysique.The line defects of three dimensional uniaxial nematics have a simple abelian algebra governing their interactions and so simply pass through one another. I will discuss, instead, biaxial nematics for which the fundamental group is non-abelian. As a result they exhibit topological entanglement/rigidity, trivalent junctions and associated networks, and stable bound states of pairs of disclinations. They can be experimentally realized in chiral nematics or in hybrid molecular-colloidal systems, realizing the notion of topological rigidity envisaged 50 years ago by Poenaru and Toulouse.Mark BowickMark Bowick was born in New Zealand, obtained his B.Sc.(Hons) from the University of Canterbury (New Zealand) and a Ph.D. in theoretical particle physics from Caltech in 1983. This was followed by a Research Associate position in the Particle Theory Group at Yale, winning the First prize award in the 1986 Gravity Research Foundation Essay Competition. This was followed by a postdoctoral position in the Center for Theoretical Physics at MIT. He joined the faculty of the Physics Department at Syracuse University in 1987, holding an Outstanding Junior Investigator award from the Department of Energy from 1987-1993 and becoming Full Professor of Physics in 1998. His research career has been split between theoretical high-energy physics and condensed matter (principally soft matter). He was elected a Fellow of the American Physical Society (Division of Condensed Matter Physics) in 2004 and Fellow of the American Association for the Advancement of Science in 2022. He received the Chancellor's Citation for Exceptional Academic Achievement in 2006 (Syracuse University) and the William Wasserstrom Prize for Excellence in Graduate Teaching and Advising in 2009 (Syracuse University). From 2011-2016 he was Director of the Soft Matter Program at Syracuse University.Since 2016 Bowick has been Deputy Director of the Kavli Institute for Theoretical Physics (Santa Barbara) and Distinguished Visiting Professor of Physics at the University of California Santa Barbara.

Jean-François JoannyMatière molle et biophysiqueCollège de FranceAnnée 2024-2025Conférence - Mark Bowick - Order in Biological DevelopmentMark BowickDeputy Director, Kavli Institute for Theoretical Physics, University of California Santa BarbaraMark Bowick est invité par l'assemblée du Collège de France sur proposition du professeur Jean-François Joanny, chaire Matière molle et biophysique.RésuméHow does a biological system set up a body plan to produce a final organism with everything in the right place and orientation? I will discuss a developmental system (parhyale) that exploits activity and cell division to establish four-fold orientational order with the flexibility of a liquid but the structural rigidity arising from orientational order. Such ideas can be tested in active (self-propelled) Voronoi models of tissue that include cell division.Mark BowickMark Bowick was born in New Zealand, obtained his B.Sc.(Hons) from the University of Canterbury (New Zealand) and a Ph.D. in theoretical particle physics from Caltech in 1983. This was followed by a Research Associate position in the Particle Theory Group at Yale, winning the First prize award in the 1986 Gravity Research Foundation Essay Competition. This was followed by a postdoctoral position in the Center for Theoretical Physics at MIT. He joined the faculty of the Physics Department at Syracuse University in 1987, holding an Outstanding Junior Investigator award from the Department of Energy from 1987-1993 and becoming Full Professor of Physics in 1998. His research career has been split between theoretical high-energy physics and condensed matter (principally soft matter). He was elected a Fellow of the American Physical Society (Division of Condensed Matter Physics) in 2004 and Fellow of the American Association for the Advancement of Science in 2022. He received the Chancellor's Citation for Exceptional Academic Achievement in 2006 (Syracuse University) and the William Wasserstrom Prize for Excellence in Graduate Teaching and Advising in 2009 (Syracuse University). From 2011-2016 he was Director of the Soft Matter Program at Syracuse University.Since 2016 Bowick has been Deputy Director of the Kavli Institute for Theoretical Physics (Santa Barbara) and Distinguished Visiting Professor of Physics at the University of California Santa Barbara.

Jean-François JoannyMatière molle et biophysiqueCollège de FranceAnnée 2024-2025Conférence - Mark Bowick - Membranes – Control by Geometry in Graphene Statistical MechanicsMark BowickDeputy Director, Kavli Institute for Theoretical Physics, University of California Santa BarbaraMark Bowick est invité par l'assemblée du Collège de France sur proposition du professeur Jean-François Joanny, chaire Matière molle et biophysique.RésuméThermalized elastic membranes show strong scale-dependence of their elastic moduli. A beautiful realization is in the physics of thermalized 2D metamaterials, such as graphene, where thermal effects already set in at microscopic length scales. This opens the way to generating materials of any required modulus from one source material in different geometrical regimes and to the manipulation of nano and micromechanical systems by geometry, rather than external fields.Mark BowickMark Bowick was born in New Zealand, obtained his B.Sc.(Hons) from the University of Canterbury (New Zealand) and a Ph.D. in theoretical particle physics from Caltech in 1983. This was followed by a Research Associate position in the Particle Theory Group at Yale, winning the First prize award in the 1986 Gravity Research Foundation Essay Competition. This was followed by a postdoctoral position in the Center for Theoretical Physics at MIT. He joined the faculty of the Physics Department at Syracuse University in 1987, holding an Outstanding Junior Investigator award from the Department of Energy from 1987-1993 and becoming Full Professor of Physics in 1998. His research career has been split between theoretical high-energy physics and condensed matter (principally soft matter). He was elected a Fellow of the American Physical Society (Division of Condensed Matter Physics) in 2004 and Fellow of the American Association for the Advancement of Science in 2022. He received the Chancellor's Citation for Exceptional Academic Achievement in 2006 (Syracuse University) and the William Wasserstrom Prize for Excellence in Graduate Teaching and Advising in 2009 (Syracuse University). From 2011-2016 he was Director of the Soft Matter Program at Syracuse University.Since 2016 Bowick has been Deputy Director of the Kavli Institute for Theoretical Physics (Santa Barbara) and Distinguished Visiting Professor of Physics at the University of California Santa Barbara.

Jean-François JoannyMatière molle et biophysiqueCollège de FranceAnnée 2024-2025Conférence - Mark Bowick - Order, Geometry and Defects: Facets of OrderMark BowickDeputy Director, Kavli Institute for Theoretical Physics, University of California Santa BarbaraMark Bowick est invité par l'assemblée du Collège de France sur proposition du professeur Jean-François Joanny, chaire Matière molle et biophysique.RésuméSharp structures can occur as minimizers of very regular problems. This means symmetry can lead us badly astray and the resultant symmetry breaking may lead to highly counter-intuitive structures. I will illustrate in a discrete example and then some continuous examples. The main soft matter example will be the emergence of faceted shapes as the ground states of liquid-crystalline vesicles and the novel ground states of crystalline order on a 2-sphere.Mark BowickMark Bowick was born in New Zealand, obtained his B.Sc.(Hons) from the University of Canterbury (New Zealand) and a Ph.D. in theoretical particle physics from Caltech in 1983. This was followed by a Research Associate position in the Particle Theory Group at Yale, winning the First prize award in the 1986 Gravity Research Foundation Essay Competition. This was followed by a postdoctoral position in the Center for Theoretical Physics at MIT. He joined the faculty of the Physics Department at Syracuse University in 1987, holding an Outstanding Junior Investigator award from the Department of Energy from 1987-1993 and becoming Full Professor of Physics in 1998. His research career has been split between theoretical high-energy physics and condensed matter (principally soft matter). He was elected a Fellow of the American Physical Society (Division of Condensed Matter Physics) in 2004 and Fellow of the American Association for the Advancement of Science in 2022. He received the Chancellor's Citation for Exceptional Academic Achievement in 2006 (Syracuse University) and the William Wasserstrom Prize for Excellence in Graduate Teaching and Advising in 2009 (Syracuse University). From 2011-2016 he was Director of the Soft Matter Program at Syracuse University.Since 2016 Bowick has been Deputy Director of the Kavli Institute for Theoretical Physics (Santa Barbara) and Distinguished Visiting Professor of Physics at the University of California Santa Barbara.

Jean-François JoannyMatière molle et biophysiqueCollège de FranceAnnée 2023-2024Polymer Physics in Cell NucleusConférence - Alexander Grosberg : Chromatin HydrodynamicsAlexander GrosbergProfesseur de physique et de mathématiques, université de New York

Jean-François JoannyMatière molle et biophysiqueCollège de FranceAnnée 2023-2024Polymer Physics in Cell NucleusConférence - Alexander Grosberg : Activity Driven Folding and SegregationAlexander GrosbergProfesseur de physique et de mathématiques, université de New York

Jean-François JoannyMatière molle et biophysiqueCollège de FranceAnnée 2023-2024Polymer Physics in Cell NucleusConférence - Alexander Grosberg : Equilibrium Polymer ModelsAlexander GrosbergProfesseur de physique et de mathématiques, université de New York

Jean-François JoannyMatière molle et biophysiqueCollège de FranceAnnée 2023-2024Polymer Physics in Cell NucleusConférence - Alexander Grosberg : Phenomenology: Chromatin is a Functional Form of DNA in the CellAlexander GrosbergProfesseur de physique et de mathématiques, université de New York

Jean-François JoannyMatière molle et biophysiqueCollège de FranceAnnée 2023-2024Séminaire - Ariel Amir : Correlations and Causation in the Bacterial Cell CycleAriel AmirInstitut WeizmannRésuméHow do cells control their size and couple the various ongoing cellular processes? Over the last decade, techniques were developed for extracting information pertinent to this question from correlations between key cell cycle variables, such as size and generation time. I will review this, as well as recent progress showing how conditional correlations (involving more than two variables) help prove the coupling between DNA replication and cell division in bacteria.

Jean-François JoannyMatière molle et biophysiqueCollège de FranceAnnée 2023-202406 - Régulation du volume des cellules : Métabolisme et croissance cellulaire

Jean-François JoannyMatière molle et biophysiqueCollège de FranceAnnée 2023-2024Séminaire - Gabriel Neurohr : Regulation and Relevance of Cytoplasm DensityGabriel NeurohrProfesseur Docteur, ETH-Zurich, SuisseRésuméThe overall concentration of macromolecules tightly regulated but can change between cell types and environmental conditions. I will talk about, or efforts to elucidate, how cytoplasm density is controlled and alterations in overall macromolecule concentration affect cell physiology.

Jean-François JoannyMatière molle et biophysiqueCollège de FranceAnnée 2023-202405 - Régulation du volume des cellules : Fluctuations et régulation du volume (2)

Jean-François JoannyMatière molle et biophysiqueCollège de FranceAnnée 2023-2024Séminaire - Samuel Safran : Nuclear Organization and Volume RegulationSamuel SafranProfesseur, Weizmann Institute of Science, Rehovot, Israël

Jean-François JoannyMatière molle et biophysiqueCollège de FranceAnnée 2023-202404 - Régulation du volume des cellules : Fluctuations et régulation du volume (1)

Jean-François JoannyMatière molle et biophysiqueCollège de FranceAnnée 2023-202403 - Régulation du volume des cellules : Volume de la cellule et volume du noyau

Jean-François JoannyMatière molle et biophysiqueCollège de FranceAnnée 2023-2024Séminaire - Marco Cosentino-Lagomarsino : Using Mathematical Models and Model-Guided Data Analysis to Understand Cellular Decisions to Grow and Progress the Cell CycleMarco Cosentino-LagomarsinoProfesseur, IFOM, Milan, ItalieRésuméThis seminar investigates the mechanisms guiding cell growth and cell cycle progression decisions, using insights from single-cell dynamics. By utilizing advanced modeling and data-analysis techniques, I will address the stochasticity, homeostatic controls, and decisional logic of these fundamental biological processes, using data from E. coli to mammalian cells, which are reshaping our current knowledge.

Jean-François JoannyMatière molle et biophysiqueCollège de FranceAnnée 2023-2024Séminaire - Matthieu Piel : Quelques couplages qui définissent la distribution de taille et de densité des cellulesMatthieu PielDirecteur de Recherche CNRS, Institut Curie, ParisRésuméLors de leurs cycles de croissance et de division, les cellules qui prolifèrent doivent coupler leur croissance en volume et leur production de macromolécules pour préserver leur densité, en particulier la concentration de leurs protéines. Elles doivent aussi coupler la durée et la vitesse de leur croissance pour assurer une distribution stable de leur taille. Je décrirai certains des mécanismes de couplage.

Jean-François JoannyMatière molle et biophysiqueCollège de FranceAnnée 2023-202402 - Régulation du volume des cellules : Modèle osmotique « pompes et fuites »

Jean-François JoannyMatière molle et biophysiqueCollège de FranceAnnée 2023-2024Séminaire - Morgan Delarue : Cell Growth under Mechanical Pressure: Effect of Macromolecular CrowdingMorgan DelarueChargé de Recherche CNRS, LAAS-CNRS, ToulouseWe will discuss the biophysical regulation of cell proliferation under spatial confinement, and the key role macromolecular crowding plays in modulating biogenesis under mechanical pressure.

Jean-François JoannyMatière molle et biophysiqueCollège de FranceAnnée 2023-202401 - Régulation du volume des cellules : Volume masse et densité d'une cellule