The electrodynamics of biological processes

The relations between field-physics and biology are systematically and continuously being inspected. In this paper, the electromagnetic field is taken into consideration, too. An objective point for a biological system of equations corresponding with MAXWELL-equations is given. Therefore processes of the growth and procreation are to be regarded as a unit. A new natural constant called b can be predetermined from field-biology. A triplet of natural constants--c, h, and b--enables a solid connection between physics and biology.     

Anharmonic analysis of arterial blood pressure and flow pulses

Fourier analysis is usually employed for the computation of blood flow in arteries. Although the orthogonality of Fourier eigenfunctions guarantees the accurate mathematical modeling of the blood pressure and flow waveforms, the physics behind this objective function is frequently missing. We propose a new method to account for the blood pressure and flow, single-cycle (systole-diastole) waveforms. It is based on the one dimensional hydrodynamic mass and momentum conservation equations for viscous flow. The similarity of the linear problem, under discussion, with related transmission line theory in electromagnetic wave propagation, permits expansion in anharmonic, non-separable eigenfunctions. In some cases one term in the expansion is adequate to fit the main peak of the observed waveforms. Analytical formulas are derived for the dependence of the pressure and flow main peaks on whole blood viscosity and distance from the heart, which interpret observations related to hypertension.     

Analysis of protein association by partitioning in aqueous two-phase polymer systems: Applications to the tetramer-dimer dissociation of hemoglobin

A new simple and rapid method for the determination of protein-protein association constants is described. By maximizing experimental conditions in which size becomes the controlling variable, analysis of the effect of protein concentration on the partitioning behavior of proteins in aqueous two-phase polymer systems permits an accurate estimate of protein association constants. When employed to investigate the tetramer-dimer dissociation of human oxy- and methemoglobin in the presence and absence of high salt concentration, values for the dissociation constant are obtained that are consistent with those obtained by other methods.     

The Temperature-gradient Tunnel: a Versatile Controlled Environment

A novel controlled-environment is described which permits simultaneousstudy in a single chamber of plant growth responses to a selectedrange of constant temperatures, under controlled conditionsof light intensity and relative humidity.     

Phase determination of x-ray reflections for membrane-type systems with constant fluid density.

A new technique for phase determination of X-ray reflections from symmetric structures is presented. This method, involving comparison of intensity data from structures with variable fluid layer thickness and constant fluid electron density, permits computation of phase angles, scaling factors, and origin reflection values independently. Possible sources of error inherent in other methods of phase determination are thereby eliminated. Results of the application of this method to model structures and to myelin data are reported. Advantages of the technique, which tests all possible phase angle combinations in a rapid fashion, are discussed.     

A new method of evaluation of the masticatory function in humans

A method is proposed to estimate mastication by three indices: chewing effect, chewing performance, chewing efficiency. Definitions are given for these terms. A new chewing test is described, permits studying the influence of the number of chewing strokes, chewing force and volume of test portion on the mastication using a group of 25 dentate persons aged 17-25 years with class I occlusion. A new approach to the estimation of chewing efficiency changes traditional views. A strong positive correlation is first found between chewing effect (A) and integrated bioelectrical activity (J) of chewing muscles with the constant number of chewing strokes. A relation between A and J is established when the number of chewing strokes increases.     

Construction of a reaction vessel for short term kinetic experiments at high or low temperatures

Construction of a constant temperature reaction vessel is described. Employment of the apparatus permits experiments that require sampling every 10 to 12 sec, under conditions of rigorous temperature control, to be done.     

A New Procedure for Quantitative Measurements of Virus Particles in Crude Preparations

A new method is described for the quantitative measurement of virus concentration in crude preparations by density gradient centrifugation and electron microscopy. The centrifugation is carried out in a specially designed centrifuge tube which permits separation and sedimentation of virus particles at different levels according to their sedimentation velocity. The gradient of a mixture of heavy and normal water (D(2)O-H(2)O) is designed to sediment the virus particles with constant velocity so that the optimal time of centrifugation can easily be calculated. The virus particles are collected on carbon-coated nickel grids floating on mercury at the bottom of the centrifuge tube and are counted by means of electron microscopy. The efficiency of the method is demonstrated with a crude plant extract of tobacco mosaic virus.     

Granulocytic Leukemoid Reactions Associated with Malignant Disease

Large upper abdominal incisional hernias have always been a vexing problem to surgeons because of the rigidity of the costal arches.With the increasing longevity of our population and the constant improvement in ways to sustain older patients during operative procedures, incisional hernias, especially of the upper abdominal area, will undoubtedly become more prevalent.A new anatomical procedure for repair, which was used in 16 cases, eliminates the necessity of the use of various prosthetic materials: extrapleural sectioning of the costal cartilages from approximately the seventh to the tenth rib permits the directional pull of the attached musculature to narrow the defect, thus allowing repair of the hernia without tension.The procedure is technically a simple one and postoperative complications are minimal.     

Effect of a constant magnetic field on biological systems]

The effect of magnetic field on biological systems is discussed. A number of existing theories are evaluated, and a conclusion is made that it is difficult to explain from the standpoint of physics, neglecting the specifies of the living cell, the effect of the constant magnetic field on biological systems at the microscopic level.     

Velocity-dependent actomyosin ATPase cycle revealed by in vitro motility assay with kinetic analysis

The actomyosin interaction plays a key role in a number of cellular functions. Single-molecule measurement techniques have been developed to study the mechanism of the actomyosin contractile system. However, the behavior of isolated single molecules does not always reflect that of molecules in a complex system such as a muscle fiber. Here, we developed a simple method for studying the kinetic parameters of the actomyosin interaction using small numbers of molecules. This approach does not require the specialized equipment needed for single-molecule measurements, and permits us to observe behavior that is more similar to that of a complex system. Using an in vitro motility assay, we examined the duration of continuous sliding of actin filaments on a sparsely distributed heavy meromyosin-coated surface. To estimate the association rate constant of the actomyosin motile system, we compared the distribution of experimentally obtained duration times with a computationally simulated distribution. We found that the association rate constant depends on the sliding velocity of the actin filaments. This technique may be used to reveal new aspects of the kinetics of various motor proteins in complex systems.     

An apparatus to measure the rate of oxygen evolution while maintaining pO2 constant during photosynthetic growth in closed culture vessels capable of operation at increased hydrostatic pressures

A double polarographic device is described which permits regulation of dissolved oxygen concentration at any preset pO₂ in suspensions or cultures of photosynthetic algae. It also simultaneously permits measurements of the rate of oxygen evolution during photosynthesis. The apparatus is designed to operate in closed vessels in the absence of a gas phase, and may be used at increased pressures tested up to 500 atmospheres. Regulation of oxygen levels was maintained constant at various preset concentrations equivalent to atmospheric pO₂ values ranging between 0.02 and 0.21 at 25°C.     

Motion of proton in double-well potential. Its possible role in the process of vision

A quantum-mechanical model that allows direct calculation of the rate of proton transfer with possible application to the early events in vision is presented. The rate is obtained in closed form in the linear-response approximation in terms of four parameters. The model permits a simple calculation of these parameters and shows modest agreement with the experimentally determined rate constant.     

Analysis of ligand-receptor binding by the difference method

A new method has been proposed for analysis of experimental data on ligand-receptor binding at equilibrium. This method makes it possible to detect heterogeneity of a receptor system in cases where the contribution of the high-affinity site to total binding is rather small and the problem of graphic discrimination of a model cannot be solved unambiguously by other methods. The difference method permits us to exclude experiments on measuring nonspecific binding. A computer program for analysis of ligand-receptor binding has been worked out in which the difference method and traditional methods of binding isotherm analysis are realized. Numerical modeling has shown that the best strategy in experimental data processing is the treatment of total binding isotherms by both the difference method and regression analysis, including the nonspecific binding constant as one of the regression parameters.     

An Apparatus for the Measurement of Leaf Dielectric Properties in the High Frequency Region

An instrument is described which permits measurements of a combinationof the dielectric constant and dielectric loss of leaves tobe made over a relatively small area of a leaf. The instrumentreadings have been shown to correlate with the water contentof filter paper, and reasonably well with the water contentof leaf tissue. Results obtained from leaves when their transpirationrate was increased are given.     

An alternative approach to generalized complementarity

An interaction viewpoint is defined for looking at natural systems. This viewpoint is seen to be connected with quantum mechanical uncertainty and measurement theory. A connection is then shown between quantum mechanical uncertainty and the workability of Grunbaüm's “infinity machines”. Finally the workability of infinity machines is related to Elsasser's “generalized complementarity”. The net result is to show that generalized complementarity is not distinct from complementarity in atomic physics but has its roots in the same place, i.e. quantum mechanical measurement theory. A model system which permits some quantification of these notions is presented.     

IMpRH server: an RH mapping server available on the Web

SUMMARY: The INRA-Minnesota Porcine Radiation Hybrid (IMpRH) Server provides both a mapping tool (IMpRH mapping tool) and a database (IMpRH database) of officially submitted results. The mapping tool permits the mapping of a new marker relatively to markers previously mapped on the IMpRH panel. The IMpRH database is the official database for submission of new results and queries. The database not only permits the sharing of public data but also semi-private and private data.     

Mise en évidence d'une relation entre la longueur el la constante de sédimentation des molécules de DNA en solution

A comparative study on sonicated calf thymus DNA was made by using electron microscopy and sedimentation methods. The length distribution, established by electron microscopy by using Kleinschmidt's technique, is related to the sedimentation curve obtained with the same solution. The relation permits a determination of the sedimentation constant corresponding to a given length up to 8000 Å and vice versa.     

Effects of zinc deficiency on the chick embryo blastoderm

A technique which permits the in vitro study of zinc deficiency in early embryos of Gallus domesticus is described using dithizone as a chelating agent. Zinc deficiency produces specific and constant lesions which are more severe as the embryo is cultivated in more early stages. The most serious alterations affect growth in general and the differentiation of the nervous system and mesoderm.     

Isoelectric focusing of interacting systems. V. Determination of ligand-binding constants

A theory is formulated for an isoelectric focusing procedure which permits determination of intrinsic ligand-binding constants. The protein is first focused in the absence of ligand, after which ligand is added to the appropriate electrode compartment and then driven by the electric field into the focusing column where it complexes with the protein. The band of protein and its complexes moves to the constituent isoelectric point. An equation linearly relates the reciprocal of the overall distance moved to the reciprocal of the local concentration of ligand. The quotient of the intercept and slope gives the intrinsic binding constant. If the concentration of ligand in the electrode compartment is used in lieu of the local concentration, an apparent constant is obtained. Extrapolation of the apparent constant to infinite dilution of protein gives the intrinsic constant. For certain systems, conditions may be realized which give an apparent constant within 4% of the intrinsic constant.