Mixed-Gen Session 2 : Active matter
Online meeting - hosted by CECAM-HQ
This is the second of a series of on line events aimed mainly at PhD students and researchers in their first post-doc. Our goal is to provide a new venue for these young scientists to share their work, get expert feedback and have an opportunity to strengthen scientific relations within the CECAM community.
The event is fully on line and will have two parts. In the first, broadcasted as a Zoom webinar, Prof. Julia Yeomans, University of Oxford, will present a general talk in the area of activated events (title and abstract below). This will be followed by seminars given by two young members of the community to describe their work in the same area. In the second part of the event, we shall move to a virtual poster session hosted in a Gather room where more PhD students and researchers in their first post-doc will present pertinent projects. The session’s speaker and other (surprise) expert guests will join us for this poster session to discuss exciting new science.
If you are a PhD student or a post-doc:
Please use the Participate Tab on this page to start the application. You will have to login using your CECAM account to access the application form. If you don't have a CECAM account yet, use the register option on the top right corner of the login page...and welcome to CECAM!
If you are a more senior scientist:
Please contact the organisers and we shall process your registration.
Submission of posters
(Please note that - at least for the time being - we shall accept posters only from PhD students or researchers in their first post-doc)
After your application is accepted, you will be able to submit a poster. In the CECAM page for this event, go to “my participation” tab and click on “Add a poster”, providing in particular title and abstract following the recommended format. Then, please upload the poster file in png or jpg by clicking on “Add a file”. These formats are strict to enable showing of the poster in the Gather session. Please upload your poster as soon as possible to enable a decision from the selection committee - see below.
Please note that posters will be visible on the Gather room associated with this session until the end of the series (July 2021) unless otherwise requested.
DEADLINE FOR SUBMISSION: TEN DAYS BEFORE THE EVENT
Selection of posters
Posters will be selected by the event organisers with the support of our main speaker and experts who will take place in the poster session.
Selection of the two talks by PhD or first year postdocs
These contributions, to be broadcasted in the Zoom webinar in the first part of the event, will be selected, after a preliminary screening by the organisers, the main speaker and guest experts, via a lottery from the posters selected for the Gather session. Please indicate in your application if you DO NOT WANT your poster to be considered for this lottery.
THE DECISION ON THE POSTER AND THE OUTCOME OF THE LOTTERY SELECTION WILL BE COMMUNICATED ONE WEEK BEFORE THE EVENT
POSTER SUBMISSIONS BEYOND THIS DEADLINE WILL BE ACCEPTED BUT NOT CONSIDERED FOR UPGRADE TO TALK. SUBMISSION WILL BE DEFINITELY CLOSED FOUR DAYS BEFORE THE EVENT.
SESSION 2. Title and abstract of talks
Phase field models for mechanobiology
Julia Yeomans, University of Oxford
A lot is known about the ways in which single cells move over a surface, but there are still many questions about the motion of confluent layers where cells coupled through intercellular junctions show a range of behaviours. In vivo cells move through the extracellular matrix, a viscoelastic polymer network. Here even single cell motility is not well understood and the mechanobiology of the collections of cells that form tissues and tumours is little explored.
Several ways to model cell motility have been described in the literature. One of the most successful has been active nematic (a.k.a. active gel) continuum models. However these do not resolve individual cells and it is hard to distinguish the roles of intercellular and intracellular forces. Models which do resolve individual cells and the interactions between them include Potts, vertex and phase field models.
This talk will concentrate on phase field models where each cell is represented by a field variable. I shall discuss possible choices of forces acting on the cells, in particular polar driving forces and intercellular activity, show how these affect the movement of confluent cell layers and compare the model results to experiments. There are many open questions. Can coarse-grained physical models give useful insight into complex biological processes? What is the most physical way to model the forces acting between cells? What exactly is contact inhibition of locomotion and what initiates the flocking of a layer of cells?
Chirality disorder in the Vicsek model
Bruno Ventejou, CEA Saclay, France
We study how chirality disorder affects the collective motion ordered phases of the Vicsek model. We present results on two cases, a Gaussian and a bimodal distribution of chirality. In both cases, we observe that the long-range ordered Toner-Tu liquid phase does not resist chirality disorder, whereas the coexistence phase made of traveling bands persists under finite disorder. Two new micro-phase separated regimes emerge, where spontaneous sorting of negative and positive chirality leads to clockwise and counter clockwise vortices or rotating polar packets.
Cell motility and polarity controls notch signaling pathway patterns in active tissues
Supriya Bajpai, IITB-Monash Research Academy, India
Cell motility and polarity dynamics in active tissues plays a very important role during the development of multicellular organisms. Intercellular signaling interactions regulate collective cell motion by allowing cells to communicate with each other by transmitting signals . A key question is how collective cell movement itself influences the spatiotemporal intercellular signaling patterns in tissues. On the one hand, the motility of cells coupled with their polarity can lead to collective motion patterns. On the other hand, intercellular signaling is responsible for generating spatial patterns of the signaling molecules. Although modeling efforts have, thus far, these two processes separately, experiments in recent years suggest that these processes influence each other. Hence, we present a model to study how the dynamics of cell motility coupled with cell polarity and intercellular signaling influence the spatiotemporal patterning of signaling molecules.
We observe a rich variety of spatiotemporal patterns of signaling molecules that is influenced by the cell motility polarity and signaling dynamics of the cells. We also observe that the collective motion of signaling patterns is due to the combined effect of the individual cell motion and spatiotemporal shift in signaling molecules that leads to an emergent time-scale of spatial rearrangement of the patterns.
Sara Bonella ( CECAM HQ ) - Organiser
Ignacio Pagonabarraga ( CECAM HQ ) - Organiser