Phys Rev E Stat Nonlin Soft Matter Phys
November 2001
Spatio-temporal bifurcations and complex dynamics in globally coupled intrinsically bistable electrochemical systems with an S-shaped current-voltage characteristic under galvanostatic control are studied theoretically on a one-dimensional domain. The results are compared with the dynamics and the bifurcation scenarios occurring in a closely related model which describes pattern formation in semiconductors. Under galvanostatic control both systems are unstable with respect to the formation of stationary large amplitude current domains.
View Article and Find Full Text PDFPhys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics
August 2000
We study complex spatiotemporal dynamics in a globally coupled bistable reaction-diffusion model on a two-dimensional spatial domain. It is demonstrated that complex behavior appears near a codimension-two bifurcation point due to the competition of spatial and temporal instabilities. We derive sufficient conditions for the appearance of mixed spatiotemporal modes, and clarify the origin of a menagery of complex dynamics, such as periodic and chaotic oscillations of current filaments, low-dimensional spatiotemporal chaos including a Shil'nikov attractor, and periodic back-and-forth motion of current density fronts.
View Article and Find Full Text PDFJ Antimicrob Chemother
August 1985
Eighty-eight of 111 patients with frequently recurring genital herpes attending five centres completed a randomized, double-blind, cross over trial with 200 mg oral acyclovir four times daily for 84 days before or after a similar course of placebo tablets. During the course of placebo 77 (88%) patients reported the development of lesions, four (5%) the development of symptoms and/or erythema but no further signs of a recurrence and seven (8%) remained entirely free of symptoms and signs. In contrast during acyclovir therapy only 11 (13%) patients reported lesions, a further 37 (42%) the development of symptoms and/or erythema only, while 40 (45%) patients remained entirely free of symptoms and signs.
View Article and Find Full Text PDFBetween 1976 and 1984 204 infections by penicillinase-producing Neisseria gonorrhoeae (PPNG) were seen in the Whitechapel Clinic. In 1984 PPNG were isolated from 4.7% of all patients attending with gonorrhoea.
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