Physics of Biological Oscillators: New Insights into Non-Equilibrium and Non-Autonomous Systems
27–30 November 2018 Chicheley Hall, Buckinghamshire Workshop Chairs: Peter Vaughan Elsmere McClintock (Lancaster University, UK) Aneta Stefanovska (Lancaster University, UK) International Scientific Committee: Martin Bier (ECU Greenville, USA) Mark Dykman (MSU, East Lansing, USA) Peter McClintock (Lancaster, UK) Antonio Politi (Aberdeen, UK) Alberto Porta (Milan, Italy) Martin Rasmussen (Imperial College London (UK) Angela Shore (Exeter, UK) Tomislav Stankovski (Skopje, Macedonia) Aneta Stefanovska (Lancaster, UK)
Living systems are characterised by rhythms, so that almost all measurable quantities (e.g. blood flow, blood pressure, respiration, temperature, brain activity, metabolite concentrations within cells, or growth rates in plants) are oscillatory in character. Slightly less well-known is that the oscillations in question have some very special characteristics. Notably, their characteristic frequencies and amplitudes vary in time, often in an almost deterministic manner. Qualitatively, the origins of some of these time variations are easy to understand, because the oscillatory process that constitute life occur in close mutual proximity and often interact with each other. It has been known since the 18th century, for example, that the heart rate is modulated by respiration, and that this is the main source of so-called heart-rate-variability (HRV). The origins of some of the other oscillations and variations are more subtle, however, and still require elucidation. The same general picture holds true on all scales from the sub-cellular, through the cellular, organ, and whole-organism levels up to whole populations, and involves a very wide range of frequencies.
The importance of biological oscillations relates not only to their inherent interest, but also to their applications in e.g. physiology and medicine where a new range of compact, "smart", semi-automatic, instruments is now in view based on analyses of the oscillations and their mutual interactions. For these, the ability to analyse and understand time-variable signals from physiological sensors is of crucial importance. Comparable applications to plants and crop productivity are in view.
Reaching an understanding of time-variable oscillations and their interactions is challenging, both experimentally and theoretically. In part, this is because the origin of the time variability is, in general, unknown (unlike the simple HRV example above, or the diurnal rhythm). In mathematical terms, the oscillations are non-autonomous, reflecting the physics of open systems where the function of each oscillator is affected by environmental influences. The physicist's instinctive resort to Fourier analysis for coping with measured time series is no longer adequate, even when using windowed algorithms. Time-frequency analysis methods based e.g. on the wavelet transform are essential. New approaches developed recently include wavelet coherence analysis and nonlinear mode decomposition. These are not yet in widespread use, and the Workshop will help to promulgate them.
Although the most important manifestation of time-variable oscillations is arguably in biological systems, they also crop up elsewhere in science, e.g. in astrophysics, or for electrons on the surface of liquid helium, with the result that scientists in these diverse areas are sometimes attempting to solve what are actually very similar mathematical problems. Potentially, they have a lot to learn from each other. The aim of the Workshop is therefore to bring together the best international experts in several seemingly very different disciplinary areas.
Who should attend?
Topics for discussion will include:
What is the future for optical techniques in biology? Particularly in the development of our ability to measure and manipulate on the nanoscale.
How can we measure force or manipulate biological systems without using attachment to unnatural substrates?
Can we use spectroscopic techniques, beyond fluorescence, at the single molecule level?