RESUMO
One of the spatiotemporal patterns exhibited by coupled map lattices with nearest-neighbor coupling is the appearance of chaotic defects, which are spatially localized regions of chaotic dynamics with a particlelike behavior. Chaotic defects display random behavior and diffuse along the lattice with a Gaussian signature. In this note, we investigate some dynamical properties of chaotic defects in a lattice of coupled chaotic quadratic maps. Using a recurrence-based diagnostic, we found that the motion of chaotic defects is well-represented by a stochastic time series with a power-law spectrum 1/fσ with 2.3≤σ≤2.4, i.e., a correlated Brownian motion. The correlation exponent corresponds to a memory effect in the Brownian motion and increases with a system parameter as the diffusion coefficient of chaotic defects.
RESUMO
Pesticides are used in large amounts in agriculture and the evaluation of their toxic effects is of major concern to public and environmental health. The aim of the present study was to investigate the genotoxic potential of a commercial formulation of the fungicide mancozeb by the micronucleus test in bone marrow and the comet assay in total blood of Wistar rats. Adult male Wistar rats were treated with a solution of mancozeb at a concentration of 40 mg/kg/day, administered intraperitoneally for 18 consecutive days, and compared to a control group. The results indicate that mancozeb induced significantly higher DNA damage as detected by the comet assay and increased the frequency of micronuclei. The results show that mancozeb is genotoxic and may adversely affect the DNA integrity of exposed organisms.
