Seminars
Mathematical Biology and Ecology seminars take place in room L3 of the Mathematical Institute from 2-3pm on Fridays of full term. You can also join us afterwards for tea in the Mathematical Institute Common Room.
Upcoming seminars:
Please note that the list below only shows forthcoming events, which may not include regular events that have not yet been entered for the forthcoming term. Please see the past events page for a list of all seminar series that the department has on offer.
Polynomial dynamical systems and reaction networks: persistence and global attractors
Abstract
Epidemiological modelling with behavioural considerations and to inform policy making
Abstract
(Associated paper: Modelling the epidemiological implications for SARS-CoV-2 of Christmas household bubbles in England in December 2020. https://doi.org/10.1016/j.jtbi.2022.111331)
In the second part, I will present a methodological pipeline developed to generate novel quantitative data on farmer beliefs with respect to disease management, process the data into a form amenable for use in mathematical models of livestock disease transmission and then refine said mathematical models according to the findings of the data. Such an approach is motivated by livestock disease models traditionally omitting variation in farmer disease management behaviours. I will discuss our application of this methodology for a fast, spatially spreading disease outbreak scenario amongst cattle herds in Great Britain, for which we elicited when farmers would use an available vaccine and then used the attained behavioural groups within a livestock disease model to make epidemiological and health economic assessments.
(Associated paper: Incorporating heterogeneity in farmer disease control behaviour into a livestock disease transmission model. https://doi.org/10.1016/j.prevetmed.2023.106019)
The determining role of cell adhesions for force transmission, mechanical activity and stiffness sensing in cells and tissues
Abstract
The role of tissue stiffness in controlling cell behaviours ranging from proliferation to signalling and activation is by now well accepted. A key focus of experimental studies into mechanotransduction are focal adhesions, localised patches of strong adhesion, where cell signalling has been established to occur. However, these adhesion sites themselves alter the mechanical equilibrium of the system determining the force balance and work done. To explore this I have developed an active matter continuum description of cellular contractility and will discuss recent results on the specific role of spatial positioning of adhesions in mechanotransduction. I show using energy arguments why the experimentally observed arrangements of focal adhesions develop and the implications this has for stiffness sensing and cellular contractility control. I will also show how adhesions play distinct roles in single cells and tissue layers respectively drawing on recent experimental work with Dr JR Davis (Manchester University) and Dr Nic Tapon (Crick Institute) with applications to epithelial layers and organoids.
Some consequences of phenotypic heterogeneity in living active matter
Abstract
In this talk I will discuss how phenotypic heterogeneity affects emergent pattern formation in living active matter with chemical communication between cells. In doing so, I will explore how the emergent dynamics of multicellular communities are qualitatively different in comparison to the dynamics of isolated or non-interacting cells. I will focus on two specific projects. First, I will show how genetic regulation of chemical communication affects motility-induced phase separation in cell populations. Second, I will demonstrate how chemotaxis along self-generated signal gradients affects cell populations undergoing 3D morphogenesis.
Cytoneme-mediated morphogenesis
Abstract
Morphogen protein gradients play an essential role in the spatial regulation of patterning during embryonic development. The most commonly accepted mechanism of protein gradient formation involves the diffusion and degradation of morphogens from a localized source. Recently, an alternative mechanism has been proposed, which is based on cell-to-cell transport via thin, actin-rich cellular extensions known as cytonemes. It has been hypothesized that cytonemes find their targets via a random search process based on alternating periods of retraction and growth, perhaps mediated by some chemoattractant. This is an actin-based analog of the search-and-capture model of microtubules of the mitotic spindle searching for cytochrome binding sites (kinetochores) prior to separation of cytochrome pairs. In this talk, we introduce a search-and-capture model of cytoneme-based morphogenesis, in which nucleating cytonemes from a source cell dynamically grow and shrink until making contact with a target cell and delivering a burst of morphogen. We model the latter as a one-dimensional search process with stochastic resetting, finite returns times and refractory periods. We use a renewal method to calculate the splitting probabilities and conditional mean first passage times (MFPTs) for the cytoneme to be captured by a given target cell. We show how multiple rounds of search-and-capture, morphogen delivery, cytoneme retraction and nucleation events lead to the formation of a morphogen gradient. We proceed by formulating the morphogen bursting model as a queuing process, analogous to the study of translational bursting in gene networks. We end by briefly discussing current work on a model of cytoneme-mediated within-host viral spread.
Modeling the electromechanics of aerial electroreception
Abstract