Biomedical subjects

M N Lorenzo

Publications and source records attributed to M N Lorenzo.

3 recordsLinked to original sources

PubMed2002

Spiral wave meandering induced by fluid convection in an excitable medium.

An isothermal reaction-diffusion system is considered in a two-dimensional fluid medium within a gravitational field. Inhomogeneities in the concentration field of the species give rise to a fluid flow due to buoyancy forces. A two-dimensional reaction-diffusion-convection model of an excitable medium is presented. The influence of hydrodynamics on spiral wave dynamics is systematically studied. A kinematic model is also introduced to better understand the mechanisms involved here.

Journal Article↗

PubMed2001

Human endothelin converting enzyme-2 (ECE2): characterization of mRNA species and chromosomal localization.

Generation of the functionally pleiotropic members of the endothelin vasoactive peptide family is critically catalyzed by unique type II metalloproteases, termed endothelin converting enzymes (ECE). Isolation of human ECE-2 (EC 3.4.24.71) cDNAs revealed deduced open reading frames of 787 and 765 amino acids with approximately 60% identity with human ECE-1. Characterization of mRNA variants revealed mRNA structural diversity at the 5'-terminus. Two mRNA species exist containing distinct first and second exons. Furthermore, in one of these species, an in-frame deletion of the intracytoplasmic domain removed 29 amino acids. Because of the previously reported human genetic diseases ascribed to germline mutations of member genes of the endothelin family, ECE2 was localized in human chromosomes with fluorescence in situ hybridization and radiation hybrid mapping to 3q28-q29 and SHGC-20171/D3S1571, respectively.

Adrenal Glands↗

PubMed1999

Colored-noise-induced chaotic array synchronization.

The effect of a time-correlated Gaussian noise on one-dimensional arrays consisting of diffusively coupled chaotic cells is analyzed. A resonance effect between the time scale of the chaotic attractor and the colored Gaussian noise has been found. As well, depending on the number of cells, coupling, and noise strength, an improvement of the synchronization or a poor synchronization between cells within the array can occur for some values of the time correlation. These nonlinear cooperative effects are studied in terms of a linear stability analysis around the uniform synchronized behavior.

Journal Article↗