ABSTRACT The detection of weak signals of nonlinear dynamical systems in noisy environments may improve with increasing noise, reaching an optimal level before the signal is overwhelmed by the noise. This phenomenon, known as stochastic... more
ABSTRACT The detection of weak signals of nonlinear dynamical systems in noisy environments may improve with increasing noise, reaching an optimal level before the signal is overwhelmed by the noise. This phenomenon, known as stochastic resonance,, has been characterized in electronic, laser, magnetoelastic, physical and chemical systems. Studies of stochastic resonance and noise effects in biological, and excitable dynamical systems have attracted particular interest, because of the possibility of noise-supported signal transmission in neuronal tissue and other excitable biological media. Here we report the positive influence of noise on wave propagation in a photosensitive Belousov-Zhabotinsky reaction. The chemical medium, which is sub-excitable and unable to support sustained wave propagation, is illuminated with light that is spatially partitioned into an array of cells in which the intensity is randomly varied. Wave propagation is enhanced with increasing noise amplitude, and sustained propagation is achieved at an optimal level. Above this level, only fragmented waves are observed.
Research Interests:
Research Interests:
Calcium is an important second messenger for cellular communication. Theoretical models help scientists understand its signalling mechanism. A comprehensive model was developed in order to minimize any limitations in the models currently... more
Calcium is an important second messenger for cellular communication. Theoretical models help scientists understand its signalling mechanism. A comprehensive model was developed in order to minimize any limitations in the models currently presented in the literature. Experimental results support the model and therefore the theoretical model provides a plausible explanation of the dynamics of the calcium-signaling mechanism. In the future,
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
In experiments on quasi-two-dimensional Turing structures, patterns form perpendicular to a concentration gradient imposed by the boundary conditions. Using linear stability analysis, with the ClO2-I2-MA (malonic acid) reaction as an... more
In experiments on quasi-two-dimensional Turing structures, patterns form perpendicular to a concentration gradient imposed by the boundary conditions. Using linear stability analysis, with the ClO2-I2-MA (malonic acid) reaction as an example, we obtain conditions on the position along the gradient direction and possible three dimensionality of the structures. Experiments on the effects of MA and starch concentrations on the position