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This work deals with a general class of two-time scales discrete nonlinear dynamical systems which are susceptible of being studied by means of a reduced system that is obtained using the so-called aggregation of variables method. This reduction process is applied to several models of population dynamics driven by demographic and migratory processes which(More)
In this work we consider a structured population with groups and subgroups of individuals. The intra-group dynamics is assumed to be fast in comparison with the inter-group dynamics. We study linear discrete models where the slow dynamics is represented by a single matrix and the fast dynamics is described by means of the first k terms of a converging(More)
In this work we extend approximate aggregation methods to deal with a very general linear time discrete model. Approximate aggregation consists in describing some features of the dynamics of a general system in terms of the dynamics of a reduced system governed by a few global variables. We present a time discrete model for a structured population (i.e.,(More)
We propose a prescription to quantize classical monomials in terms of symmetric and ordered expansions of noncommuting operators of a bosonic theory. As a direct application of such quantization rules, we quantize a classically time evolved function O(q,p,t), and calculate its expectation value in coherent states. The result can be expressed in terms of the(More)
Zinc, cadmiun and mercury dihalide react with 4-acetylpyridinthiosemicarbazone (4-aptsc) to give complexes with 1:1 and 2:1 ligand/metal stoichiometric ratios. These metals are effec­ tive templates for the Schiff-base condensation o f 4-acetylpyridine with semicarbazide to give the complexes [M(4-apsc)XJ and [M(4-apsc)2X 2] where M = Zn, Cd or Hg and X =(More)
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