Simple heuristics: From one infinite regress to another?

Gigerenzer, Todd, and the ABC Research Group argue that optimisation under constraints leads to an infinite regress due to decisions about how much information to consider when deciding. In certain cases, however, their fast and frugal heuristics lead instead to an endless series of decisions about how best to decide.

Jordan isomorphism of purely infinite C*-algebras

We prove that every unital bounded linear mapping from a unital purely infinite C*-algebra of real rank zero into a unital Banach algebra which preserves elements of square zero is a Jordan homomorphism. This entails a description of unital surjective spectral isometries as the Jordan isomorphisms in this setting.

Future novel threats and opportunities facing UK biodiversity identified by horizon scanning

1. Horizon scanning is an essential tool for environmental scientists if they are to contribute to the evidence base for Government, its agencies and other decision makers to devise and implement environmental policies. The implication of not foreseeing issues that are foreseeable is illustrated by the contentious responses to genetically modified herbicide-tolerant crops in the UK, and by challenges surrounding biofuels, foot and mouth disease, avian influenza and climate change.

Infinite Dimensional Banach spaces of functions with nonlinear properties

The aim of this paper is to show that there exist infinite dimensional Banach spaces of functions that, except for 0, satisfy properties that apparently should be destroyed by the linear combination of two of them. Three of these spaces are: a Banach space of differentiable functions on Rn failing the Denjoy-Clarkson property; a Banach space of non Riemann integrable bounded functions, but with antiderivative at each point of an interval; a Banach space of infinitely differentiable functions that vanish at infinity and are not the Fourier transform of any Lebesgue integrable function.

Electromagnetic wave diffraction from an infinite array of complex-shaped microstrip reflectors

A numerical-analytical method is developed for solving surface integral equations (IEs) describing electromagnetic wave diffraction from arrays of complex-shaped planar reflectors. Solutions to these equations are regularized via analytical transformation of the separated singular part of the matrix kernel. Basis functions satisfying the metal-edge condition are determined on the entire surface of the complex region. The amplitude and phase responses of arrays consisting of polygonal reflectors are numerically investigated.

Organometallic polymers: An infinite organoplatinum chain in the solid state formed by (C CH center dot center dot center dot ClPt)hydrogen bonds

The new platinum complex [PtCl[C6H2(CH(2)NMe(2))(2) -2,6-(C=CH)-4)] exhibits a polymeric linear -C=CH ... ClPt-hydrogen-bonded structure in the solid state.

Performance analysis of an infinite array linear clustered plug nozzle

The effects of module shape, module design, three dimensional flow field generated by modules, and partition of primary nozzle on the performance of an infinite array linear clustered plug nozzle are discussed. The module shape is a critical element for nozzle performance and the partition of the primary nozzle with round-to square modules causes a vacuum thrust reduction with respect to two-dimensional model. The performance analysis of different module configuration allows weighing separately the role of clustering and the role of module design. In operating conditions characterized by turned off modules the performance loss is larger, but the difference due to the module shape are smaller and mostly due to the module contribution. The performance of the plug nozzle can be improved by module design, which reduces the module exit flow nonuniformity.