On the unified laws of excitability,activity and interactivity of physiological systems

Summary Laws of excitability, activity and interactivity were established in their basic forms concerning not only the slope and time factors of an effective stimulus to a physiological system, but also concerning relative differences in the stimulus, moving stimulus, reciprocal inhibition, etc., and further the basis was established for the unification of these laws in the above various situations.     

On the interactivity and recovery function in physiological systems

Summary As an extention of the law of activity (Sato, 1968), the law of interactivity was established by which new physiological meanings are added to such well known basic concepts as facilitation and occlusion in the central nervous system, and super- and subnormal phases in the recovery function of physiological systems.     

Delays in physiological systems

Summary In comparison to most physical or chemical systems, biological systems are of extreme complexity. In addition the time needed for transport or processing of chemical components or signals may be of considerable length. Thus temporal delays have to be incorporated into models leading to differential-difference and functional differential equations rather than ordinary differential equations. A number of examples, on different levels of biological organization, demonstrate that delays can have an influence on the qualitative behavior of biological systems: The existence or non-existence of instabilities and periodic or even chaotic oscillations can entirely depend on the presence or absence of delays with appropriate duration.     

Control strategies in physiological systems

In this paper, written for a general audience, I review and contrast various strategies that the body uses to control homeostasis and movement. Messages, signals, communication channels, and control systems are dealt with from both a cellular and an integrative perspective. The major global control strategies are feedback, feedforward, and adaptive control, and examples of each are presented to highlight advantageous and disadvantageous features. Many physiological systems use these three strategies in combination.     

On the stock estimation for some fishery systems

In this work we address the stock estimation problem for two fishery models. We show that a tool from nonlinear control theory called “observer” can be helpful to deal with the resource stock estimation in the field of renewable resource management. It is often difficult or expensive to measure all the state variables characterising the evolution of a given population system, therefore the question arises whether from the observation of certain indicators of the considered system, the whole state of the population system can be recovered or at least estimated. The goal of this paper is to show how some techniques of control theory can be applied for the approximate estimation of the unmeasurable state variables using only the observed data together with the dynamical model describing the evolution of the system. More precisely we shall consider two fishery models and we shall show how to built for each model an auxiliary dynamical system (the observer) that uses the available data (the total of caught fish) and which produces a dynamical estimation of the unmeasurable stock state x(t). Moreover the convergence speed of towards x(t) can be chosen.     

Interpreting both short- and long-term power laws in physiological clearance curves

Clearance curves for radiocalcium can be separated into a part closely fitted by at^−α or by at^−αexp−βt,0.2<α<0.5; the latter changes into asecond power function At^−W, where W is usually between about 0.9 and 1.5. The previous model for explaining the first power without compartments is extended to allow for the second power; according to this, each injected radiocalcium atom undergoes bone—non-bone cycles with a probability p that such a cycle is broken by excretion in the non-bone phase. It is shown in particular how increasing p from zero to nearly 1 influences the observed clearance curves: for p = 0, W>1.5. while, as p approaches unity, W approaches the value for the short term power α.     

Coevolution of physiological systems

Coevolution is the interaction in the process of evolution of different species that are closely related biologically but do not exchange genetic information. In this paper, we address the problem of coevolution of the whole organism’s physiological systems as a process of the interrelated development of structure and function as well as their regulatory systems during the formation of living organisms. We consider the coevolution of osmoregulation and the nitrogen metabolism type, systemic and individual coevolutionary strategies of cell volume regulation in poikiloosmotic and homoiosmotic animals, coevolution of effectory organs and endocrine factors in the development of water–salt homeostasis, co-involvement of neurohypophyseal nonapeptides and glucagon-like peptide-1 in the regulation of the renal function aimed at stabilizing physico-chemical parameters of extracellular fluids which make up the internal environment of the organism.     

On some metric properties of the systems of compartments

Rules for the enumeration of the strong components of a graph and for the calculation of its variable adjacency matrix are presented. A new method is given to calculate the transfer function of a graphy by analyzing the strong components of the graph, the elementary paths between two nodes, and the linear subgraphs.     

On some topological properties of the systems of compartments

Compartment systems are often used as models for tracer and drug kinetics. The structure of a compartment system is here analyzed by means of theory of graphs methods. In particular the precursor-successor relationship between any two compartments is classified according to the structure of the graph of the system and to the values of the elements of the matrix associated with it. Supported jointly by NASA and AEC.     

On some metric properties of the systems of compartments

Rules for the enumeration of the strong components of a graph and for the calculation of its variable adjacency matrix are presented. A new method is given to calculate the transfer function of a graphy by analyzing the strong components of the graph, the elementary paths between two nodes, and the linear subgraphs. This work was supported in part by the United States Atomic Energy Commission and the National Aeronautics and Space Administration.     

Effect of detoxified Aflatoxin B1 contaminated products on some in vivo and in vitro plant physiological systems

Aflatoxin B₁ was detoxified (60 %) enzymatically by horseradish peroxidase. In another set of experiments the toxin was detoxified (97 %) by a combination of enzyme and microwave treatments. Chloroform extracts of these reaction products were used to study their effects on some important physiological processes of higher plants. Cell mass growth in suspension culture of Catharanthus roseus showed 34 % and 77 % respective increase in dry weight after 4 to 8 weeks of incubation at room temperature (22 EC) without toxin but in presence of toxin only 21 % and 43 % dry weight increase occurred in the same time interval. Aflatoxin B₁ showed a profound effect on pollen germination and pollen tube morphology leading to only 40 % germination and several morphological anomalies in Catharanthus roseus and Haemanthus Katherinae. Embryogenic callus of Santalum album could give rise to only 60 % somatic embryo in presence of 1mM toxin with several abnormalities which is much less compared to 94 % conversion to distinct bipolar embryos in case of control set without toxin. Only 49 % seeds of Arachis hypogaea germinated in presence of 1mM aflatoxin in the germinating medium compared to 71 % germination in control media.     

On the laws of psychophysics

Experiments by S. S. Stevens (Stevens, 1957, and Stevens and Galanter, 1957) and his collaborators indicate that the so-called logarithmic Weber-Fechner Law is not realized in most human perceptions. Instead, a power law seems to emerge over a large number of sensory continua. This is important because for a long time the logarithmic law was looked upon as almost the only possible psychophysical law. The logarithmic law appeared desirable intuitively because it made the sensation depend on the relative values of the stimuli and not on their absolute values. This is, of course, useful for evolutionary reasons. Some other reasons are also discussed by Stevens (1961).     

几种盐生植物抗盐生理指标的研究

研究对几种盐生植物进行了相关抗盐生理指标测定,抗盐生理指标测定结果表明：盐生植物组的功能叶中ＭＤＡ含量平均值高于非盐生植物对照组,而膜透性平均值低于对照组;盐生植物组Ｃ１＾－离子含量平均值高于对照组,可溶性糖含量平均值低于对照组,脯氨酸含量在所测３种渗透调节剂中所占比例最高,而且盐生植物组平均值高于对照组;无机渗透剂与有机渗透剂之间似有互补关系;Ｃ１＾－离子含量与肉质性存在一定正相关;盐生植物组和     

On the interpretation of binding isotherms in complex biological systems. Apparent homogeneity of some heterogeneous systems

A simple treatment of the effect of site heterogeneity upon binding isotherms is presented, which is applicable to the analysis of data obtained from measurements of hormone, drug, or lectin binding to membranes and cell surfaces. Using this treatment, isotherms corresponding to various distributions of binding constants have been fitted to examples of experimental binding data ordinarily interpreted in the context of a homogeneous binding site model. It is found that these data do not permit one to exclude the alternate possibility of a broad distribution of the binding constant K. If a homogeneous binding site model can be satisfactorily fitted to the data, it is probable that the value of K obtained by this procedure is equal or nearly equal to the number average value of K in the actual (unknown) distribution.