The research in exercise physiology is done in collaboration with Bengt Saltin at the Copenhagen Muscle Research Center , August Krogh Institute, Rigshospitalet, in Copenhagen and Maria Zakynthinaki. The aim of the research is to model the physiological responses to varying exercise intensities, using tools from dynamical systems and apply the findings to training methodology and testing. I presented a weekly seminar series on this at the Departament de Matemàtica Aplicada I, Universitat Politècnica de Catalunya, Barcelona. We have currently developed a new model of oxygen uptake kinetics in response to exercise which has also resulted in new methods for calculating the oxygen demand and hence deficit and dept. These new methods are particularly useful at maximal or near maximal exercise intensities. Other interests include modelling and analyzing the physiological response to different forms of interval training and the effect of altitude on performance. Regarding altitude we are also interested in the question of how to improve performance at altitude.
The work in biomechanics involves the use tools from dynamical systems to analyze and model a variety of problems involving nonlinear time series and apply the findings to training methodology and testing. Animation tools are also used as an aid to further understanding the biomechanical processes. We currently have work on modelling balance and stability following a perturbation from quiet stance. This can be used to track improvements in balance or to identify muscle imbalances producing nonsymmetric ranges in motion. We also have work on analyzing the tremor due to fatigue resulting from repeated exercise until failure, in which we are interested in looking at changes in tremor as we approach failure. This has important applications for determining the maximum number of repetitions possible before failure for exercises where failure at maximum load is undesirable for safety reasons. It also has applications for identifying wether a failure was at maximum load or wether it was premature and hence a greater load could have been achieved. Other interests include applications of different forms of flexibility and strength training.
My work in fluids is based on models of the large scale underlying circulations commonly found in many estuarine fluid flows. From an understanding of the transport across barriers formed from the unstable and stable manifolds of hyperbolic fixed and periodic orbits, cantori (and their periodic approximations) and KAM tori (for which the transport across is zero) found within the flow, we were able to understand the large scale underlying transport and pattern formation mechanisms in an estuarine flow. We then applied this knowledge to problem of pollution dynamics in the estuarine environment. In particular we applied it to the problems of patchiness (ie. regions of high concentration) in clouds of pollution and to the reduction of the environmental impact associated with discharge sites for pollution out falls. This was work done with Ron Smith and Cecil Scott while at the department of Mathematical Sciences, Loughborough.
Previously as a post doc I have worked at the California Institute of Technology in the department of Control and Dynamical Systems with Stephen Wiggins on chaos and transport in large (ocean) scale, geophysical flows. Following this I was a post Doc with Peter Leth Christiansen at the Institute of Mathematical Modelling, Technical University of Denmark where I worked with Ole Bang on chaos in nonlinear optics and in particular in what are known as chi(2) materials . I then worked as a visiting professor with Giorgos Tsironis at the Department of Physics, University of Crete and the Institute of Electronic Structure and Laser, FORTH, where I worked on breathers and in particular chaotic breathers found in a damped driven DNLS lattice. Following this I was a visiting professor with Amadeu Delshams at the Universitat Politecnica de Catalunya, Departament de Matematica Aplicada I and then at the Centre de Recerca Matematica, Barcelona. After this I was a researcher working in the Departament de Matematiques, Universitat Autonoma de Barcelona with Maria Zakynthinkai.
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