[About the modeling of developing systems].

The purpose of the communication is to discuss the general properties of developing systems, the methods of their modeling, and the question of their complexity. The concept "complex system" is conditional, a more precise meaning has the complexity of the model describing the phenomenon. Two propositions are discussed: (1) The complexity of basic models is minimal. In other words, complex basic models are not necessary at all. (2) Alive systems are simpler than lifeless. Many processes in the inanimate nature, too, can also be assigned to developing systems. Nevertheless there is a distinction between alive and lifeless systems. The distinction consists in that alive beings can put a purpose before themselves and develop according to it. For this reason, they can be described by simpler basic models.

[The concept of intuitive and logical in neurocomputing].

A concept of the arrangement of the neural computer is proposed, which allows one to solve some problems of modern neural computing and to describe the effects of intuition, creation, as well as a number of effects that are not yet sufficiently understood. The concept is based on the idea that the activity of knowledge acquisition and of information store are complementary and should be performed by two different subsystems, and the subsystem able to learn has to involve the "noise", i.e., an occasional element. The problem is discussed to what extent the artificial intellect could simulate the living one. A set of possible methods are suggested in order to simulate the effects that traditionally were prescribed to the human organism only (the sense of humor, the sleep and dreams, etc.).

[Use of the standard theory of electronic transitions in the description of oscillations in the kinetics of electron transfer in reaction centers of purple bacteria].

The standard theory of the electron transfer between donor and acceptor molecules was used to describe oscillations in the reduction kinetics of the intermediate electron acceptor BA and the primary electron acceptor HA. The kinetics of the reduction of BA and HA were simulated on the basis of the model in which one and two accepting modes were used. A principal experiment is offered for the selection of the suitable theory for adequate description of oscillations in the kinetics of electron transfer in the reaction centers of purple bacteria.

[Origination of Pareto distribution in complex dynamic systems].

The Pareto distribution, whose probability density function can be approximated at sufficiently great chi as rho(chi) - chi(-alpha), where alpha > or = 2, is of crucial importance from both the theoretical and practical point of view. The main reason is its qualitative distinction from the normal (Gaussian) distribution. Namely, the probability of high deviations appears to be significantly higher. The conception of the universal applicability of the Gauss law remains to be widely distributed despite the lack of objective confirmation of this notion in a variety of application areas. The origin of the Pareto distribution in dynamic systems located in the gaussian noise field is considered. A simple one-dimensional model is discussed where the system response in a rather wide interval of the variable can be quite precisely approximated by this distribution.

[The temperature factor and magnetic noise under the conditions of stochastic resonance of magnetosomes].

The influence of magnetic noise on the dynamics of magnetic nanoparticles under the conditions of stochastic resonance is considered. The effect of the magnetic noise is shown to be equivalent to the growth of the effective thermostat temperature for the particles at the permanent actual temperature of the medium. This regularity may be used for testing the hypothesis on the involvement of magnetic nanoparticles in the formation of biological effects of weak magnetic fields.

[The paradox of magnetobiology: analysis and prospects for solution].

The wording, content, and corollaries of the so-called "kT problem" are considered. The problem points to the paradox of the biological effects of weak low-frequency magnetic fields. The conventional wording of the problem contains implicit assumptions the analysis of which shows their incomplete physical validity.

Kinetic model of bacteriorhodopsin photocycle: pathway from M state to bR.

A model of the last parts of the bacteriorhodopsin (bR) photocycle is proposed on the basis of experimental data for the kinetic behavior of the 'O' intermediate during a temperature pulse in distilled water suspension. The model includes the previously proposed (but not well characterized) intermediate 'N' between the 'M' and 'O' states of bR. This intermediate exists in fast temperature-dependent quasi-stationary equilibrium with the red-shifted intermediate 'O' and has a maximum of absorption close to the bR spectrum.

On the possibility of reduction of dissipative structure models to a simple form.

A multicomponent reaction-diffusion system containing two different space scales (contrasting system) is considered. It is shown that if the system answers several conditions enumerated, it can be reduced to a bicomponent system which describes a dissipative structure either of a peak or of a step type. While in the first case the original and the final systems are equivalent only in the neighbourhood of zero, in the second case the equivalence is more general as the solution of these systems does not leave the region for which the procedure of reduction was developed.

On the formation of unique dissipative structures.

We consider a simple model for the formation of dissipative structures. In general there exists a multitude of stable final states. We show, however, that when the diffusion constant increases during the development of the system, a stationary state is reached which does not depend on the choice of initial conditions. We also show that a uniquely defined final state builds up when the system is initially strongly excited on one side.

On kinetics of phase transitions in cell membranes.

Phase transitions in a bicomponent lipid membrane are considered. It is shown that in this case metastable states practically do not arise and phase transitions are smooth and hysteresisless. An elastic frame on the surface of the membrane changes the character of phase transitions: they become sharp and hysteretic. The role of membrane phase transitions for regulation of cell processes is considered.

A mathematical model of periodic processes in membranes (with application to cell cycle regulation).

A mathematical model of the regulation of the cell cycle by the plasma membrane is suggested. The model is based on the hypothesis that structural transitions of the cell membrane play an important role in the regulation of cell division. Conditions of transition from the proliferating state to the resting state and back are investigated. Possible qualitative differences between models of the cell cycle of a normal and a tumour cell are pointed out.

Catastrophic extinction, noise-stabilized turbulence and unpredictability of competition in a modified Volterra-Lotka model.

Spatial coexistence and competition among species is investigated through a modified Volterra-Lotka model which takes into account sexual breeding. This allows the population specific growth rate to depend on the population density. As a result of this modification the degeneracy inherent in the classical model is eliminated and qualitatively novel regimes are observed, as demonstrated by parametric analysis of the model. In the case where the corresponding parameters of competing species do not differ significantly the model can be reduced to a single Ginzburg-Landau type equation. The spatially distributed model is analyzed both in the absence and in the presence of noise mimicking inherent fluctuations in birth and death rates. It is shown that noise can qualitatively change the behavior of the system. Not only does it induce the formation of spatial patterns, but also switches on endless turbulent-like rearrangement of the system. When initially unpopulated habitat is occupied by competing species even a very low-intensity noise makes the final state of the system totally unpredictable and sensitive to any fluctuations. (c) 1996 American Institute of Physics.

[Bimodal changes in the germination of seeds subjected to heat treatment]. / Bimodal'noe izmenenie vskhozhesti semian pri teplovom vozdeistvii.

Novel explanation is proposed for the improvement of low quality seeds by pre-sowing treatment with factors of various nature (heat and sonic treatment, electrical field of corona discharge, laser irradiation). The increase in seed germination percentage is caused by slowing-down of seed water uptake as a result of closing the aquaporin water canals.

[Radiation entropy and its role in the process of photosynthesis]. / Ob éntropii izlucheniia i ee roli v protsesse fotosinteza.

The paper deals with the following problems: 1) radiation entropy and the value of maximum performance coefficient of photosynthesizing systems eta m; 2) problem of physical meaning of eta m and on its association with real processes in photosynthesis. It has been shown that for calculating entropy of nonequilibrium radiation its origin should be known and that the value eta m does not practically limit the processes which proceed in photosynthesis.

[Generation of valuable information and the problem of goal self-setting in living systems]. / Generatsiia tsennoi informatsii i problema samopolaganiia tseli v zhivykh sistemakh.

The problem of origination of capacity for goal self-setting is discussed. It was shown that the definition "goal" in living systems differs from the definition "target function" in physical problems concerned with nonliving systems. It was also shown that the main goal of the elements of a system is the storage of information. In biology, this goal is the extension of the principle of struggle for existence. Conditions were determined that the dynamic system describing the goal self-setting process must satisfy. It was shown that living systems meet these conditions. In inorganic nature, such systems may also arise but only as a result of long-term evolution, after which they become living.

[Biophysical concept of the human autodiagnostic system]. / Biofizicheskaia kontseptsiia autodiagnosticheskoi sistemy cheloveka.

A possible neurophysiological mechanism of the therapeutic effect of weak influences was proposed, which is based on the following assumptions: 1. In the organism, there is an autodiagnostic system, which serves for the accumulation and processing of information on the state of the organs to diagnose a desease. 2. The autodiagnostic disease is a recognizing system, i. e., a neuronet, which is constructed and functions according to the paradigms of neurocomputing. 3. Systemic (psychosomatic) diseases appear to result from erroneous diagnosis due to the defects of the autodiagnostic system. The influence of puncture on biologically active points corrects these defects, providing a positive therapeutic effect. A theoretical model for the structure and functioning of the autodiagnostic system is discussed. It is shown that the structure of the model autodiagnostic system coincides with that of Rexede plates forming the gray substance of the spinal cord. The experimental data on Rexede plates and their connections with organs and corresponding biologically active points are discussed. A relationship between the concept of the autodiagnostic system and the basic principles of alternative eastern medicine is discussed. It is shown that the Chinese model of puncture therapy represents a verbal description of the topological features of the phase space of the mathematical model for the recognizing neuroprocessor.

[Physical model of initial stages of energy transformation during oxidative phosphorylation]. / Fizicheskaia medel' nachal'nykh stadii transformatsii énergii pri okislitel'nom fosforilirovanii.

A model of non-dissipative energy transmission of activated electron into proton subsystem energy was considered. The model is based on the effect of resonance tunneling of the electrons, which provides for non-dissipative energy transmission. Within the scope of the model the energized proton formed in the protein membrane structure has enough energy to perform phosphorylation.

[The "protein-machine" concept and its consequences]. / Kontseptsiia "belok-mashina" i ee sledstviia.

Analysis is presented of the concept "protein-machine" and implying consequences, both of theoretical and experimental character. The approach "protein-machine" is compared with other approaches--"coherent excitation", "molecular dynamics" and "limited diffusion". In terms of the approach "protein-machine" valuable information inserted in the biological macromolecule and determining its functions is taken into account. It reflects the biological specificity and at the same time removes mystic shadow from this concept.

[Minimal mixture principle as a method of choosing the form of a dynamic model]. / Printsip minimal'nogo smesheniia kak metod vybora formy dinamicheskoi modeli

The extremality principle for molecular processes in biological systems is considered. The principle is based on an assumption that the main function of biological processes is the separation of the "product" from the "scheme". The form of the dynamical model of the process is determined from the requirement of the "minimum mixture". As an example Selkov's model of glycolysis is considered.

[Kinetics of primary photocycle stages of bacteriorhodopsin at low temperatures]. / Kinetika pervichnykh stadii fototsikla bakteriorodopsina pri nizkikh temperaturakh.

According to the changes of absorption spectra kinetics of two primary stages of bacteriorhodopsin photochemical cycle was studied in the temperature range 160 +/- 300 degrees K. It has been found that for K610-L550 transition in the range under study the rate-temperature relationship is described by Arrhenius law with the activation energy Ea = 0.68 eV. For L550-M412 transition Ea = 0.69 eV. The character of temperature relationship, of the rate and amplitude for this transition indicates that at T less than or equal to 270 degrees K a phase transition is possible.