81 research outputs found
Propagation failure of traveling waves in a discrete bistable medium
Propagation failure (pinning) of traveling waves is studied in a discrete
scalar reaction-diffusion equation with a piecewise linear, bistable reaction
function. The critical points of the pinning transition, and the wavefront
profile at the onset of propagation are calculated exactly. The scaling of the
wave speed near the transition, and the leading corrections to the front shape
are also determined. We find that the speed vanishes logarithmically close to
the critical point, thus the model belongs to a different universality class
than the standard Nagumo model, defined with a smooth, polynomial reaction
function.Comment: 8 pages, 6 eps figures, to appear in Physica
Asymptotic integral kernel for ensembles of random normal matrices with radial potentials
We use the steepest descents method to study the integral kernel of a family of normal random matrix ensembles with eigenvalue distribution P_{N}(z_{1},...,z_{N}) = Z_{N}^{-1} e^{-NSigma_{i=1}^{N}V_{alpha}(z_{i})} Pi_{1leqi<jleqN}|z_{i}-z_{j}|^{2} where V_{alpha}(z)=|z|^{alpha}, z in C and alpha in ]0,infty[. Asymptotic analysis with error estimates are obtained. A corollary of this expansion is a scaling limit for the n-point function in terms of the integral kernel for the classical Segal--Bargmann space
Social Class
Discussion of class structure in fifth-century Athens, historical constitution of theater audiences, and the changes in the comic representation of class antagonism from Aristophanes to Menander
Technical Change and Industrial Dynamics as Evolutionary Processes
Technical Change and Industrial Dynamics as Evolutionary Processes
Functional screening for G protein-coupled receptor targets of 14,15-epoxyeicosatrienoic acid
Ex vivo relaxations of pulmonary arteries induced by prostacyclin mimetics are highly dependent of the precontractile agents
9α,11β-PGF2 and its stereoisomer PGF 2α are novel agonists of the chemoattractant receptor, CRTH2
AbstractCRTH2 is a recently described chemoattractant receptor for the prostaglandin, PGD2, expressed by Th2 cells, eosinophils and basophils, and believed to play a role in allergic inflammation. Here we describe the potency of several PGD2 metabolites at the receptor to induce cell migration and activation. We report for the first time that the PGD2 metabolite, 9α,11β-PGF2, and its stereoisomer, PGF2α, are CRTH2 agonists. 9α,11β-PGF2 is a major metabolite produced in vivo following allergen challenge, whilst PGF2α is generated independently of PGD synthetase, with implications for CRTH2 signalling in the presence or absence of PGD2 production
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