From food chains to airline route maps, complex networks are ubiquitous. Complex networks are a particularly powerful way to study biological systems, for which the quantity of data available has exploded recently, for example through genome projects, the human connectome project and protein data banks. These systems’ intricate structures and dynamics routinely span multiple temporal and structural scales, defying ‘bottom-up’ attempts to describe them. The potency of networks to traverse these scales is one of the most exciting aspects of complex network research.
In July 2016, I began a postdoctoral position in Prof. Ed Bullmore’s group in Cambridge, working on network approaches to study structural and functional MRI brain images. I am working primarily on the PSYSCAN project, which is an international EU project and aims to develop and validate imaging biomarkers for psychosis. My role is to assemble network analysis methods to diagnose and predict the psychosis trajectories of individual patients. Outside of the PSYSCAN project, I am also interested in network motif analysis and the relationship between the spatial embedding of networks and their topology.
My interest in complex networks stems from my PhD work on the ultrafast photophysics of biological and organic systems. A new technique called 2D electronic spectroscopy (2DES) has provided evidence that quantum effects might be important during photosynthesis. However, 2DES experiments are hard to interpret. Therefore during my PhD I worked closely with experimentalists to develop advanced methods to analyse and simulate 2DES experiments. A particular highlight was working with experimentalists from the Cambridge Optoelectronics group on the organic semiconductor pentacene, resulting in a publication in which we underlined the role of molecular vibrations in these systems. Vibrations are also important in biological light harvesting systems and towards the end of my PhD I used a model known as the ‘nonlinear network model’ to study the low frequency vibrations in the archetypal Fenna-Matthews-Olson light harvesting pigment protein complex. I showed that nonlinear vibrations could be biologically relevant for energy transfer in this complex.
“Low dimensional morphospace of topological motifs in human fMRI brain networks”, Morgan, Achard, Termenon, Bullmore and Vértes, bioRxiv, June 2017
“Quantum-coherent dynamics in photosynthetic charge separation revealed by wavelet analysis“, Romero, Javier, Chin, Morgan, Novoderezkhin, Plenio and van Grondelle, Scientific Reports, 7: 2890, 2017
“Nonlinear network model analysis of vibrational energy transfer and localisation in the Fenna-Matthews-Olson complex”, Morgan, Cole and Chin, Scientific Reports, 6: 36703, 2016
“Real-time observation of multiexcitonic states in ultrafast singlet fission using coherent 2D electronic spectroscopy”, Bakulin, Morgan, Kehoe, Wilson, Chin, Zigmantas, Egorova and Rao, Nature Chemistry, 8, 16-23, 2016