Dependence of "macroscopic fluctuations" from cosmophysical factors. Spatial anisotropy

It was shown in experiments with collimators that the changes with time in the shape of histograms constructed from the measurements of the alpha-activity of 239Pu microsamples depend on the direction of the flow alpha-particles. If the flow of alpha-particles was directed to the Polar Star, the dependence of the probability of the realization of histograms of similar shape on time disappeared. The measurements of alpha-particle flows directed to the East and West revealed a high probability of the repeated realization of histograms of similar shape in 1436 min, i.e., in a sederal day. A comparison of "west" and "east" histograms showed a high probability of the realization of similar "west" histograms 718 min (half a sideral day) later than "east" histograms. The results suggest that the shape of histograms depends on the pattern of the starry sky and the space-time inhomogeneity corresponding to this pattern.     

Dependence of 'macroscopic fluctuations" on geographic coordinates (from materials of Arctic (2000) and Antarctic (2001) expeditions

The detailed structure of histograms constructed from the results of synchronous measurements of the alpha-activity of 239Pu microsamples, conducted in Pushchino (Moscow Region, Russia) and on board the ship "Academician Fedorov" during the Arctic and Antarctic expeditions (2000 and 2001) was analyzed. It was shown that, if the histograms were constructed over a total period of 15 min and more, the "local zone effect" and the circadian periodicity in the similarity of histogram structure, observed during measurements in Pushchino, are not found in measurements on board the ship near the North Pole (latitude 82 degrees). If the histograms were constructed over a total time of 1 min, a strict periodicity ("stellar day" 23 h 56 min) in the appearance of similar histograms in Pushchino and the Arctic and a strict synchronicity of the appearance of similar histograms of measurements in Pushchino and on board the ship at the same local geographical time were observed. During the Antarctic expedition, the effect of synchronicity of the appearance of similar histograms in Pushchino and on board the ship decreased as the ship moved towards the South Pole and the difference in latitude between the points of measurements increased.     

A theoretical approach to "macroscopic fluctuations" effect

At present there is no generally accepted theory of the effect of macroscopic fluctuations. It the article, an attempt is made to relate this effect to some basic properties of quantum systems, in particular, to the formal absence of dynamic chaos in these systems. Based on this approach, it was shown why the level of the effect must be of the same order of magnitude as the level of noise and cannot exceed this level as the number of experiments increases. It was shown qualitatively what is the cause of the similarity of histograms observed in different experiments.     

"Runaway" social evolution: reinforcing selection for inbreeding and altruism.

Kin selection theory predicts that altruistic behaviors, those that decrease the fitness of the individual performing the behavior but increase the fitness of the recipient, can increase in frequency if the individuals interacting are closely related. Several studies have shown that inbreeding therefore generally increases the effectiveness of kin selection when fitnesses are linear, additive functions of the number of altruists in the family, although with extreme forms of altruism, inbreeding can actually retard the evolution of altruism. These models assume that a constant proportion of the population mates at random and a constant proportion practices some form of inbreeding. In order to investigate the effect of inbreeding on the evolution of altruistic behavior when the mating structure is allowed to evolve, we examined a two-locus model by computer simulation of a diploid case and illustrated the important qualitative features by mathematical analysis of a haploid case. One locus determines an individual's propensity to perform altruistic social behavior and the second locus determines the probability that an individual will mate within its sibship. We assumed positive selection for altruism and no direct selection at the inbreeding locus. We observed that the altruistic allele and the inbreeding allele become positively associated, even when the initial conditions of the model assume independence between these loci. This linkage disequilibrium becomes established, because the altruistic allele increases more rapidly in the inbreeding segment of the population. This association subsequently results in indirect selection on the inbreeding locus. However, the dynamics of this model go beyond a simple "hitch-hiking" effect, because high levels of altruism lead to increased inbreeding, and high degrees of inbreeding accelerate the rate of change of the altruistic allele in the entire population. Thus, the dynamics of this model are similar to those of "runaway" sexual selection, with gene frequency change at the two loci interactively causing rapid evolutionary change.     

Optical methods for exploring dynamics of single copies of green fluorescent protein.

Single copies of four different phenolate ion mutants of the green fluorescent protein (GFP) exhibit a complex blinking and fluctuating behavior, a phenomenon that is hidden in measurements on large ensembles. Both total internal reflection microscopy and scanning confocal microscopy can be used to study the blinking dynamics, and autocorrelation analysis yields histograms of the correlation times for many individual molecules. While the total internal reflection method can follow several single molecules simultaneously, the confocal method offers higher time resolution at the expense of parallelism. We compare and contrast the two methods in terms of the ability to follow the complex dynamics of this system.     

The effect of newly synthesized psychotropic preparations on the "open field" behavior of rats]

The results of effect of some new synthesized psychotropic drugs of nootropic series on rats' behavior in "open field" are given. The increase of locomotive activity and decrease of emotional tension correlated with the rise of rats' ability to learning during working-out of avoidance reaction in shuttle-box, e.i. conditionally reflectory memory. It has been concluded that the study of dynamics of behavioral reactions in "open field" may be used for testing of new synthesized psychotropic drugs of nootropic series.     

Estimation of the abundance of <Emphasis Type="Italic">Nucella heyseana</Emphasis> (Mollusca: Gastropoda) by the mark and recapture technique

The abundance of the predatory gastropod, the Far East dogwhelk Nucella heyseana in the Vostok Bay of the Sea of Japan was assessed by applying the mark and recapture technique with reverse sampling. It was shown that assessment of mollusk abundance using this approach did not differ significantly from that resulting from the frame technique. It was determined that the number of the dogwhelks decreased in recent years in the surveyed area. In implementing long-term research, including the seasonal dynamics of the number of N. heyseana and other mollusk species similar to it in their biology and behavior, we suggest applying, concurrently with the mark and recapture technique, other methods, enabling one to obtain more adequate figures of their numbers in the cold season.     

Linear Discrete Population Models with Two Time Scales in Fast Changing Environments I: Autonomous Case

In this work we consider a structured population with groups and subgroups of individuals. The intra-group dynamics is assumed to be fast in comparison with the inter-group dynamics. We study linear discrete models where the slow dynamics is represented by a single matrix and the fast dynamics is described by means of the first k terms of a converging sequence of different matrices. The number k can be interpreted as the ratio between the two time scales.The aim of this work is to extend aggregation techniques to the case of fast changing environments. The main idea of aggregation is to build up a new system, with lower dimension, that summarizes the information concerning the fast process. This "aggregated" system provides essential information on the original one. It is shown that the asymptotic behavior of the original system can be approximated by the asymptotic behavior of the aggregated system when the ratio between the two time scales is large enough.We present an example of an age structured population in a patchy environment. The migration process is assumed to be fast in comparison with the demographic process. Numerical simulations illustrate that the asymptotic growth rate and the stable age distribution of the population in the original and the aggregated systems are getting closer as the ratio k increases.     

Dynamics of the noisy neural network

The dynamic features of interspike interval sequences and structures of spatiotemporal patterns of firing in a coupled noisy neural network are investigated. The system displays complex dynamics under periodic external stimuli. The dynamics is modulated by a periodic impulse-like synaptic current which relates to a global coupling interaction between neurons. The firings of the stimulated neurons are phase-locked to this current. In addition, the interspike interval histograms are studied for the case of frozen noise which does not change its value within a time interval once it has been distributed onto the network. It is found that the peaks in these histograms are located at integer multiples of the period of the external stimulus, and the heights of these peaks decay exponentially, which corresponds to the experimental results. Received: 12 April 1997 / Accepted in revised form: 7 May 1997     

Evolution of recombination in "host-parasite" systems. Multilocus models

Evolution of the recombination system caused by antagonistic species interactions (host and parasite, for example) was studied. The genetic structure of host population as well as that of parasite is explicitly present in our models. The selection intensity depends on host's resistance and parasite's virulence, both controlled by polygenic systems. The rec-system dynamics was numerically studied using the genetic operators method. It is shown that high-recombination alleles of the rec-modificator can have a short-term selective advantage in both interacting populations simultaneously.     

Comparison of forms of "unfit histograms" by a wavelet transform method

Two methods checking changes in time of histogram patterns were investigated. These methods are relied on discrete wavelet transform. The result is that in the some cases these methods can more effectively to examine latency in the behavior of histograms form constructed by on overlapping short segments of experimental data.     

Creative dynamics approach to neural intelligence

The thrust of this paper is to introduce and discuss a substantially new type of dynamical system for modelling biological behavior. The approach was motivated by an attempt to remove one of the most fundamental limitations of artificial neural networks — their rigid behavior compared with even simplest biological systems. This approach exploits a novel paradigm in nonlinear dynamics based upon the concept of terminal attractors and repellers. It was demonstrated that non-Lipschitzian dynamics based upon the failure of Lipschitz condition exhibits a new qualitative effect — a multi-choice response to periodic external excitations. Based upon this property, a substantially new class of dynamical systems — the unpredictable systems — was introduced and analyzed. These systems are represented in the form of coupled activation and learning dynamical equations whose ability to be spontaneously activated is based upon two pathological characteristics. Firstly, such systems have zero Jacobian. As a result of that, they have an infinite number of equilibrium points which occupy curves, surfaces or hypersurfaces. Secondly, at all these equilibrium points, the Lipschitz conditions fails, so the equilibrium points become terminal attractors or repellers depending upon the sign of the periodic excitation. Both of these pathological characteristics result in multi-choice response of unpredictable dynamical systems. It has been shown that the unpredictable systems can be controlled by sign strings which uniquely define the system behaviors by specifying the direction of the motions in the critical points. By changing the combinations of signs in the code strings the system can reproduce any prescribed behavior to a prescribed accuracy. That is why the unpredictable systems driven by sign strings are extremely flexible and are highly adaptable to environmental changes. It was also shown that such systems can serve as a powerful tool for temporal pattern memories and complex pattern recognition. It has been demonstrated that new architecture of neural networks based upon non-Lipschitzian dynamics can be utilized for modelling more complex patterns of behavior which can be associated with phenomenological models of creativity and neural intelligence.     

Characteristics of motor and cardiac activity in men during the performance of test "shooter"

Subject's behavior and electrocardiogram were investigated during execution of the test "Shooter". Three kinds of strategies were used by subjects during the task performance. Three types of the motor activity of subjects were also found in the "interresulting" periods during the system activity. The spatial and temporal characteristics of these types of activity were similar to those during the actual achieving the result. Differences in the dynamics of the R-R-interval changes were found in the periods before achieving the positive or negative result.     

Global bifurcation structure of a Bonhoeffer-van der Pol oscillator driven by periodic pulse trains

The Bonhoeffer-van der Pol (BVP) oscillator is a valuable dynamical system model of pacemaker neurons. Isochrons, phase transition curves (PTC), and two dimensional bifurcation diagrams served to analyze the neuron's response to periodic pulse stimuli. Responses are described and explained in terms of the nonlinear dynamical system theory. An important issue in the generation of spikes by pacemaker neurons is the existence of both slow and fast dynamics in the state point's trajectory in the phase plane. It is this feature in particular that makes the BVP oscillator a faithful model of living pacemaker neurons. Comparison of the model's responses with those of a living pacemaker was based also on return maps of interspike intervals. Analyzed in detail were the complex discharges called stammering which involve interspike intervals that arise unpredictably and exhibit histograms with several modes separated by the equal intervals.Supported by Trent H. Wells Jr. Inc.     

Motor polarization dominance and "animal hypnosis"

Two kinds of dominanta were simultaneously formed under conditions of chronic experiments in rabbits. The motor polarization dominanta was formed under exposure of the right sensorimotor cortex of an animal to direct anodic current, and the state of "animal hypnosis" (the second dominanta) was induced. Animal behavior and electrophysiological characteristics were recorded. It was shown that the "animal hypnosis" induced at the optimum of the right motor polarization dominanta inhibited the motor reaction of the "dominant" extremity to testing stimuli. After the "animal hypnosis session, exposure of the right sensorimotor cortex to anodic current produced the latent excitation focus, which did not reach the level of summation. Two days later, exposure to testing stimuli developed the latent foci at first in the right cortex and then in subcortical structures. In the course of recovery of the motor polarization dominanta and its further change for the state characteristic of the "animal hypnosis", the patterns of cortical EEG coherence in the delta range typical of each kind of dominanta alternated in parallel with the time course of state changes.     

Radially softening diffusive motions in a globular protein

Molecular dynamics simulation, quasielastic neutron scattering and analytical theory are combined to characterize diffusive motions in a hydrated protein, C-phycocyanin. The simulation-derived scattering function is in approximate agreement with experiment and is decomposed to determine the essential contributions. It is found that the geometry of the atomic motions can be modeled as diffusion in spheres with a distribution of radii. The time dependence of the dynamics follows stretched exponential behavior, reflecting a distribution of relaxation times. The average side chain and backbone dynamics are quantified and compared. The dynamical parameters are shown to present a smooth variation with distance from the core of the protein. Moving outward from the center of the protein there is a progressive increase of the mean sphere size, accompanied by a narrowing and shifting to shorter times of the relaxation time distribution. This smooth, "radially softening" dynamics may have important consequences for protein function. It also raises the possibility that the dynamical or "glass" transition with temperature observed experimentally in proteins might be depth dependent, involving, as the temperature decreases, progressive freezing out of the anharmonic dynamics with increasing distance from the center of the protein.     

An experimental study and a mathematical model of interactions in mixed culture of invertebrates and algae in the "producer-consumer" aquatic biotic cycle

An experimental investigation was carried out, and a mathematical model of interaction between invertebrates (infusoria Paramecium caudatum and rotifera Brachionus plicatilis) and algae (Chlorella vulgaris and Scenedesmus quadricauda) in the "producer-consumer" aquatic biotic cycle with spatially divided links was constructed. The model describes the dynamics of a mixed culture of infusoria and rotifera in the "consumer" link, when they consume a mixed culture of algae coming from the "producer" link. A negative influence of products of algae Scenedesmus metabolism upon the reproduction of infusoria P. caudatum was revealed. Taking this into account, a qualitative coincidence of the results of mathematical modeling with experimental data was obtained. It was shown that the co-existence of mixed algae culture in the "producer" link with invertebrates in the "consumer" link in the "producer-consumer" aquatic biotic cycle is impossible because of the displacement of infusoria P. caudatum by rotifera Brachionus plicatilis.     

Searching for Food or Hosts: The Influence of Parasitoids Behavior on Host–Parasitoid Dynamics

A host–parasitoid system with overlapping generations is considered. The dynamics of the system is described by differential equations with a control parameter describing the behavior of the parasitoids. The control parameter models how the parasitoids split their time between searching for hosts and searching for non-host food. The choice of the control parameter is based on the assumption that each parasitoid maximizes the instantaneous growth rate of the number of copies of its genotype. It is shown that optimal individual behavior of parasitoids, with respect to time sharing between hosts and food searching, may have a stabilizing effect on the host–parasitoid dynamics.     

Co-operative dynamics in organelles

Some organelles produce elementary life phenomena which are characterized by the spontaneous formation and/or maintenance of ordered macroscopic dynamics like e.g. the shortening of sarcomeres in striated muscle and the transmission of electrical impulses in an axon. It has been widely accepted that such organelles are organized molecular systems where molecular elements work independently under constraint of a more or less rigid and regular structure of the system. On the other hand, such organelles should be regarded as self-organizing systems if the ordered macroscopic dynamics are self-organized. As the macroscopic dynamics gradually emerge, the microscopic dynamics of its elements become linked to each other through a feedback loop. It is crucial for the feedback loop to operate that the macroscopic dynamics are "free" in their behavior. In the present paper, it is pointed out that the traditional view of independent molecular elements has been obtained from experiments in which, by means of external constraint, the macroscopic dynamics is "clamped". Under such conditions, the self-organizing system may behave as an organized one. Based on synergetics we propose criterions for proving self-organizing systems, and, by applying the criterions, we conclude that skeletal muscle actomysin is a co-operative element in the sense of self-organization.     

Cross-correlation as a method for discriminating impulses on multineuronal recordings

Impulses series, singled out from multineuronal activity by means of amplitude discriminator, were analyzed by creating crosscorrelation histograms. The authors consider that in studying of net brain activity with crosscorrelation method of analysis "window" discrimination of impulses series in multineuronal record is a quite correct method and may be used along with discrimination of spikes by form. It is shown that the size of the "window", used for singling out of separate impulses series, is not a determining parameter in search of temporal dependence in the activity of the investigated cells, as final discrimination of the impulses of dependently acting neuronal pairs occurs at the level of the crosscorrelation method itself. The step of the analysis under the use of crosscorrelation method is of decisive significance for revealing of direct interconnections between neurones in the cases when these connections are masked on histograms with wide peaks reflecting the influences of common sources, on the recorded cells.