Non-cooperative Systems Research Articles

Displacement analysis of binding inhomogeneities in crude extracts of receptors.

Guidelines are given to distinguish different kinds of binding inhomogeneities of non-radiolabeled ligands in crude extracts of receptors if an appropriate 'binding analogue' of the displacers is available in radiolabeled form. Three minimal models for the simplest types of binding inhomogeneities are analysed theoretically. These models include a cooperative system (with two interacting sites on the same receptor molecule) and two non-cooperative systems (one of them with a single-site receptor having two conformational states in equilibrium and the other with two single-site receptors independent of each other). In certain cases one can distinguish these systems experimentally. Furthermore, if a group of displacers is already classified according to the above models, then dissociation constants can be determined. The quantitative comparison of these displacers on the basis of their dissociation constants is more appropriate (e.g. in Quantitative Structure Activity Relationship studies) than on the basis of their ID50 and Ki values or Hill coefficients, which is often done.

Properties of a system of currency baskets

This paper interprets the resulting regime when a number of countries tie their currencies to unilaterally designed baskets of other currencies, as a noncooperative exchange rate system. Consistency and stability of such a system of currency baskets are investigated through an application of the Frobenius-Perron Theorem on semipositive square matrices. It is established that devaluations preserve (while sufficiently large revaluations undermine) these properties. This asymmetry is caused by the use of arithmetic baskets which do not preserve effective weights when exchange rates differ from their base settings.

Study of hydrogen exchange in hemoglobin as a function of fractional ligand saturation.

We have studied the hydrogen-exchange kinetics of hemoglobin A0 as a function of ligand, CO, saturation. In the noncooperative system, azide binding to methemoglobin, the alterations in exchange kinetics are proportional to the average degree of ligation. However, in the case of CO binding to deoxyhemoglobin the changes in hydrogen-exchange pattern run ahead of the degree of ligation. The data can be best fitted assuming that all the liganded species, regardless of the number of ligands, show the same exchange properties. This two-state behavior must be the consequence of the fact that all the conformational changes leading to increased solvent accessibility take place when the first ligand is bound. Studies of the effect of pH changes and carbamoylation on the relationship between ligand binding and hydrogen exchange show that the observed differences of hydrogen exchange between deoxy and the liganded state are linked to the alkaline Bohr effect and to the state of the alpha-N-termini. As a consequence, at pH 9 despite a highly cooperative ligand binding isotherm the differences in hydrogen exchange between the deoxy and fully liganded species have vanished. We have to conclude that the hydrogen exchange is mirroring only the first part of the overall R to T transition. In all the experiments with pH changes and carbamoylation it is the liganded form that shows changes becoming more like the deoxy state. This is not consistent with a model where ligand binding removes a structural restriction in the less accessible deoxy state.

AN INFORMATION THEORY OF GAME SYSTEMS

We define non-cooperative game systems and cooperative game systems from a viewpoint of information theory. Concerning the both systems we show some sufficient conditions under which players can obtain the total information on the other players' strategies from a sequence of observations. In a cooperative case we give a numerical model and calculate the amounts of information obtained from the sequential observations by the players in a cooperative group.

A boundary sedimentation velocity method for determining nonspecific nucleic acid-protein interaction binding parameters

An absolute method for measuring affinity constants and binding site sizes for the non-sequence-specific binding of protein to single- or double-stranded polynucleotide chains is described, based on the difference in the rate of sedimentation of free protein and the protein-nucleic acid complexes. In the form outlined, the technique can measure binding constants ranging from 10 3 to 10 6 m −1; methods for extending the range of measurable binding constants are also described. Data obtained for the noncooperative binding of ribonuclease to DNA are presented as fully worked-out examples of the method, and the extension of this approach to other noncooperative and cooperative protein-nucleic acid binding systems is discussed.

Collision Avoidance: The State of the Art and Some Recent Developments and Analyses

There has been a long history of development of collision avoidance systems (CASs) starting in about 1945; but there has been little progress in terms of operational use. At first, most development concentrated on noncooperative radar systems but by about 1960 it was realized that radar, while feasible, could not offer an economically practicable solution. Efforts since then have been concentrated on cooperative systems, cooperative in the sense that any two aircraft involved in a threatening encounter must both be equipped with mutually compatible devices and there must be intercommunications of necessary data.

Fluorescence correlation spectroscopy. I. Conceptual basis and theory

AbstractWe describe a method for determining chemical kinetic constants and diffusion coefficients by measuring the rates of decay of spontaneous concentration fluctuations. The equilibrium of the system is not disturbed during the measurement. We measure the number of molecules of a specified type in a defined open volume as a function of time and compute the time course of the deviations from the thermodynamic mean concentration. The method is based on the principle that the rates of decay of spontaneous microscopic fluctuations are determined by the same phenomenological rate coefficients as those of macroscopic departures from equilibrium which result from external perturbations. Hence, an analysis of fluctuations yields the same chemical rate constants and diffusion coefficients as are measured by conventional procedures. In practice the number of the specified molecules is measured by a property such as absorbance or fluorescence which is specific and sensitive to chemical change. The sample volume is defined by a light beam which traverses the cell. As the molecules appear in or disappear from the light beam, either due to diffusion or chemical reaction, their concentration fluctuations give rise to corresponding fluctuations of the intensity of absorbed or emitted light. This paper presents the theory needed to derive chemical rate constants and diffusion coefficients from these fluctuations in light intensity. The theory is applied to three examples of general interest: pure diffusion in the absence of chemical reaction; the binding of a small rapidly diffusing ligand to a larger slowly diffusing macromolecule; and a unimolecular isomerization. The method should be especially useful in studying highly cooperative systems, relatively noncooperative systems with intermediate states closely spaced in free energy, small systems, and systems not readily subject to perturbations of state.

Future vehicle detection concepts

This paper presents some of the economic and technical considerations for development of future noncooperative vehicle-detector systems. Vehicle-detector accuracy requirements, installation cost, location, and the roadway environment are used to develop a set of preferred vehicle detector characteristics. In addition, a description of vehicle detectors, considered for development by the Bureau of Public Roads, and some of the current vehicle-detector concepts under development, are presented.