Information Technology Reference
In-Depth Information
At the level of body tissues, an obvious example is the function of the cerebral
cortex. At the same time, reaction-diffusion phenomena are characteristic for other
organs. For example, cardiac arrhythmias and the phenomenon of sudden death
occur as a result of pathological wave modes in the myocardium.
Widely known are the modes of concentration fluctuations in chemical and
biochemical systems, in biological membranes and cells, i.e., on the supramolecular
level.
Finally, nonlinear dynamics can lead to collective excitations, the so-called
solitons which are waves propagating over long distances along the molecular
core, i.e., at the molecular level.
A remarkable feature of these environments is that regardless of the physical
implementation, they all show the same macroscopic behavior:
Local or global (throughout the entire volume of the medium) fluctuations in the
concentrations of medium components
Local areas of high concentration (concentration pulses) propagating in the bulk
of the medium
Trigger modes propagating in the medium switching from one state to another
one
Formation of stable and persistent over time dissipative structures with a
nonuniform distribution of concentrations of medium components
Chemical reaction-diffusion systems and, above all, those media in which
Belousov-Zhabotinsky reactions take place apparently show the best promise for
creating neuro-like information processing tools. Trigger mode and the “leading
center” mode of these media are shown in Fig.
4.6
.
Fig. 4.6 Trigger mode (a) and the “leading center” mode (b) in the Belousov-Zhabotinsky
medium
