Thursday, 28 April 2016

BioMaths Colloquium - 29/04/2016

BioMaths Colloquium Series - 2015/16

29 April 2016 - 3pm Maths Seminar Room 

(room 224 Talbot Building 2nd floor)

Spatio-temporal modelling of gene regulatory networks: The role of molecular movement

Prof Mark Chaplain

Gene regulatory networks (GRN), i.e. DNA segments in a cell which interact with each other indirectly through their RNA and protein products, lie at the heart of many important intracellular signal transduction processes. In this talk, we will present and analyse mathematical models of various GRNs using partial differential equations (PDE) and stochastic PDEs. We will then analyze a mathematical model of a canonical gene regulatory network consisting of a single negative feedback loop between a protein and its mRNA (e.g. the Hes1 transcription factor system). 

The model consists of two partial differential equations describing the spatio-temporal interactions between the protein and its mRNA in a one-dimensional domain. Such intracellular negative feedback systems are known to exhibit oscillatory behavior and this is the case for our model, shown initially via computational simulations. In order to investigate this behavior more deeply, we undertake a linearized stability analysis of the steady states of the model. 

Our results show that the diffusion coefficient of the protein/mRNA acts as a bifurcation parameter and gives rise to a Hopf bifurcation. This shows that the spatial movement of the mRNA and protein molecules alone is sufficient to cause the oscillations. Our result has implications for transcription factors such as p53, NF-kappaB and heat shock proteins which are involved in regulating important cellular processes such as inflammation, meiosis, apoptosis and the heat shock response, and are linked to diseases such as arthritis and cancer.

The discussions will continue over biscuits and tea/coffee after the seminar. 
Hope to see many of you!

Friday, 22 April 2016

Biosciences Seminar Speaker 26 April 2016

Biosciences Seminar Series - Spring 2016
26 April 2016 - 1pm - Zoology Museum

Measuring the rate and nature of evolution 

using comparative methods

Prof Robert Freckleton

The comparative method is one of the most important methods for studying evolution and adaptation with applications in ecology, behaviour and conservation. Modern comparative approaches recognize that phylogenetic relationships create structure in data that can be used to improve statistical inference as well as uncover the signal of different evolutionary processes. 

In this talk I present recent work on applying comparative methods to problems in the analysis of data and modelling evolution. In the first part of the talk I discuss problems with heterogeneous data quality and the analysis of experimental data on multiple species. In the second part of the talk I look at non-Brownian evolution resulting from interactions between species during their evolution. 

I highlight the use of new statistical methods that can  be used to model complex evolution of traits in adaptive radiations and present examples of where these have been applied.

Hope to see many of you - everyone most welcome to attend!