4,633 research outputs found
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)
Angular Distribution of Decay Leptons from e^+e^- \to W^+W^- at Threshold
The reaction produces a -boson pair with a
non-trivial spin correlation at threshold. This correlation leads to a
characteristic angular correlation between the leptons produced in (angles relative to the beam direction): . If only the is observed, its angular
distribution is , implying a forward-backward asymmetry of 3/8. An analytic result
is also given for the azimuthal correlation. These results are reproduced by a
Monte Carlo program, that also enables us to study the effects of the decay
width. The threshold behaviour, which stems from the dominance of
-exchange, is contrasted with that due to - and -exchange,
which is relevant for annihilation in the helicity state .Comment: 10 pages, 6 figures, LaTeX, simpler derivation of main results, also
added a comparison with Monte Carlo expectation
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
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.
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
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