Global bifurcations of closed invariant curves in two-dimensional maps: a computer assisted study, Int. from an invariant circle for two-parameter families of maps of the plane: A computer-assisted study, Comm. The Bogdanov map: bifurcations, mode locking, and chaos in a dissipative system, Int.
In a previous cross-sectional study of 100 asymptomatic individuals aged 49-69, we reported age-related decline in immediate and delayed memory that was steeper in apolipoprotein E (apoE)-e4/4 homozygotes than in members of other genetic subgroups. These findings were preliminarily based upon the statistical problem of multiple comparisons. We therefore… (More)
The goal of this study was to evaluate a community-based psychoeducational-nursing intervention designed to teach home caregivers to manage behavioral problems of persons with Alzheimer's disease and related dementias (ADRD) using the Progressively Lowered Stress Threshold (PLST) model, and to compare this intervention with routine information and referrals… (More)
We examine existence and stability of relative equilibria of the n-vortex problem specialized to the case where N vortices have small and equal circulation and one vortex has large circulation. As the small circulation tends to zero, the weak vortices tend to a circle centered on the strong vortex. A special potential function of this limiting problem can… (More)
In this paper we examine the question of existence of a two-dimensional universally observable system, i.e., dynamics which are observable by every continuous nonconstant real-valued function on the state space. We are motivated by the work of D. McMahon, who proved that a class of three-dimensional manifolds with horocycle flow have this property. We… (More)
The aim of this work is to provide an insight of an idealized model of a planetary ring. The model is a limit case of the planar circular restricted 1+n body problem, where an infinitesimal particle moves under the gravitational influence of a large central body and n smaller bodies located on the vertices of a regular n-gon. When considering n tending to… (More)