Biomedical subjects

H A Cerdeira

Publications and source records attributed to H A Cerdeira.

4 recordsLinked to original sources

PubMed2001

How does a periodic rotating wave emerge from high-dimensional chaos in a ring of coupled chaotic oscillators?

A route to typical rotating waves from high-dimensional chaos is investigated in diffusively coupled chaotic Rössler oscillators. By increasing the coupling from zero, a high-dimensional spatiotemporal chaos changes into a coherent state, which is periodic in time and well ordered in space, through consecutive transitions. A crossover transition from spatially random chaos to spatially ordered chaos with phase locking and orientational equality (for two directions) breaking is a crucial step for establishing the typical spatial order of the rotating wave.

Journal Article↗

PubMed2001

Partial synchronization and spontaneous spatial ordering in coupled chaotic systems.

A model of many symmetrically and locally coupled chaotic oscillators is studied. Partial chaotic synchronizations associated with spontaneous spatial ordering are demonstrated. Very rich patterns of the system are revealed, based on partial synchronization analysis. The stabilities of different partially synchronous spatiotemporal structures and some dynamical behaviors of these states are discussed both numerically and analytically.

Journal Article↗

PubMed1999

Fractal properties of DNA walks.

We describe two dimensional DNA walks, and analyze their fractal properties. We show results for the complete genome of S. cerevisiae. We find that the mean square deviation of the walks is superdifussive, corresponding to a fractal structure of dimension lower than two. Furthermore, the coding part of the genome seems to have smaller fractal dimension, and longer correlations, than noncoding parts.

DNA, Fungal↗

PubMed1999

Growth kinetics and morphology of a ballistic deposition model that incorporates surface diffusion for two species.

We introduce a ballistic deposition model for two kinds of particles (active and inactive) in (2+1) dimensions upon introducing surface diffusion for the inactive particles. A morphological structural transition is found as the probability of being the inactive particle increases. This transition is well defined by the change in the behavior of the surface width when it is plotted as a function of time and probability. The exponents alpha and beta calculated for different values of probability show the same behavior. The presence of both types of particles gives rise to three different processes that control the growing surface: overhanging, nonlocal growth, and diffusion. It finally leads to a morphological structural transition where the universality changes away from that of Kardar, Parisi, and Zhang, in (2+1) dimensions, but not into that of Edwards and Wilkinson.

Journal Article↗