The point of maximum curvature as a marker for physiological time series

We present a geometric analysis of the model of Stirling. In particular we analyze the curvature of a heart rate time series in response to a step like increment in the exercise intensity. We present solutions for the point of maximum curvature which can be used as a marker of physiological interest. This marker defines the point after which the heart rate no longer continues to rapidly rise and instead follows either a steady state or slow rise. These methods are then applied to find analytic solutions for a mono exponential model which is commonly used in the literature to model the response to a moderate exercise intensity. Numerical solutions are then found for the full model and parameter values presented in Stirling

Risk, precaution and science: towards a more constructive policy debate. Talking point on the precautionary principle

Few issues in contemporary risk policy are as momentous or contentious as the precautionary principle. Since it first emerged in German environmental policy, it has been championed by environmentalists and consumer protection groups, and resisted by the industries they oppose (Raffensperger & Tickner, 1999). Various versions of the principle now proliferate across different national and international jurisdictions and policy areas (Fisher, 2002). From a guiding theme in European Commission (EC) environmental policy, it has become a general principle of EC law (CEC, 2000; Vos & Wendler, 2006). Its influence has extended from the regulation of environmental, technological and health risks to the wider governance of science, innovation and trade (O'Riordan & Cameron, 1994)

Sudakov Logarithm Resummation for Vector Boson Production at Hadron Colliders

A complete description of W and Z boson production at high-energy colliders requires the resummation of large Sudakov logarithms which dominate the production at small transverse momentum. Currently there are two techniques for performing this resummation: impact parameter space and transverse momentum space. We argue that the latter can be formulated in a way which retains the advantages of the former, while at the same time allowing a smooth transition to finite order dominance at high transverse momentum.Comment: 5 pages, LaTeX, 2 figures, epsfig, contribution to the proceedings of the UK Phenomenology Workshop on Collider Physics, 19-24 September 1999, Durham, to be published in J. Phys.

Power correlations in cosmology: limits on primordial non-Gaussian density fields

We probe the statistical nature of the primordial density field by measuring correlations between the power in adjacent Fourier modes. For certain types of non-Gaussian field, these k-space correlations would be expected to be more extended than for a Gaussian field, providing a useful discriminatory test for Gaussian fields. We apply this test to the combined QDOT and 1.2-Jy IRAS galaxy survey and find the observed density field to be in good agreement with having Gaussian density fluctuations for modes with k < 0.1 h/Mpc. From this result we are able to set quantitative limits on a class of possible non-Gaussian distributions -- the product of a Gaussian field with an independent stochastic field. The maximum sensitivity is to modulations of a Gaussian field with coherence scales of 30 Mpc/h and the rms modulation on this scale cannot greatly exceed unity. We discuss the improvements to this limit likely to be set by future surveys.Comment: MNRAS in press. 6 pages TeX including Postscript figures. Uses mn.sty and epsf.st

Opening Up the Politics of Knowledge and Power in Bioscience

Public engagement is not in tension with science, but actually a way to be more rigorous - as well as more democratic - about social choice of biotechnology