Showing papers by "David A. Kessler published in 1996"
TL;DR: A mean-field theory for the evolution of RNA virus populations, which operates with a distribution of the population in a one-dimensional fitness space, and is valid for sufficiently smooth fitness landscapes.
Abstract: We present a mean-field theory for the evolution of RNA virus populations. The theory operates with a distribution of the population in a one-dimensional fitness space, and is valid for sufficiently smooth fitness landscapes. Our approach explains naturally the recent experimental observation [I. S. Novella et al., Proc. Natl. Acad. Sci. U.S.A. 92, 5841--5844 (1995)] of two distinct stages in the growth of virus fitness.
274 citations
TL;DR: The investigation that led the FDA to assert its jurisdiction over cigarettes and smokeless tobacco and the policy considerations that shaped the final rule are described.
Abstract: On August 23, the Food and Drug Administration (FDA) issued a regulation restricting the sale and distribution of cigarettes and smokeless tobacco to children and adolescents.1 This regulation, known as a rule, is the most far-reaching measure ever instituted to reduce the use of tobacco by young people. This article describes the investigation that led the FDA to assert its jurisdiction over cigarettes and smokeless tobacco and the policy considerations that shaped the final rule. The FDA announced on February 25, 1994, that it was considering regulating tobacco products under the authority of the Federal Food, Drug, and Cosmetic Act. . . .
107 citations
TL;DR: In this paper, a new topological theory for the limiting form of the autocorrelation function for small displacements is developed and shown to be in substantial agreement with the measurements.
19 citations
TL;DR: In this article, the steady-state spiral in the thin-interface limit, including the effects of diffusion of the slow field, is solved numerically using a generalization of the hybrid scheme of Keener.
10 citations
TL;DR: It is found that the spiral interface is stable for a sufficiently high diffusion constant of the slow field to result in the onset of hypermeandering and spiral breakup.
Abstract: The two-component reaction-diffusion excitable medium is treated numerically in the free boundary limit for the fast field. We find that the spiral interface is stable for a sufficiently high diffusion constant of the slow field. The spiral wave (interface) undergoes a core-meander instability via a forward Hopf bifurcation as the diffusion constant decreases. A further decrease of the diffusion constant is found to result in the onset of hypermeandering and spiral breakup. We demonstrate quantitative convergence of the dynamics of reaction-diffusion system to its free boundary limit.
9 citations