The metabolism of homogenates of the mouse epididymis

This study has attempted an evaluation of the in vitro metabolic characteristics of the epididymis of the mouse and a definition of areas for further research pursuant to the elucidation of the role of this organ in the process of sperm maturation and storage. Optimal conditions were ascertained for the manometric measurement of total respiration and for the estimation of glycolytic activity by assay of lactate accumulation and phosphate esterification in fluoride poisoned homogenates. Homogenates of mouse kidney were utilized in all experiments for comparative purposes. The in vitro data presented indicate the epididymis to be predominantly oriented to a glycolytic metabolism. It is suggested that this metabolic orientation when considered with the results of other investigators is compatible with a hypothesis for the secretion of lactic acid by the epididymal epithelium into the lumen of the epididymal canal for spermatozoan utilization.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50125/1/1030660305_ftp.pd

On the relation between the Hartree-Fock and Kohn-Sham approaches

We show that the Hartree-Fock (HF) results cannot be reproduced within the framework of Kohn-Sham (KS) theory because the single-particle densities of finite systems obtained within the HF calculations are not $v$-representable, i.e., do not correspond to any ground state of a $N$ non-interacting electron systems in a local external potential. For this reason, the KS theory, which finds a minimum on a different subset of all densities, can overestimate the ground state energy, as compared to the HF result. The discrepancy between the two approaches provides no grounds to assume that either the KS theory or the density functional theory suffers from internal contradictions.Comment: 7 pages, ReVtex, revised and accepted by Physics Letters

Pairing correlations beyond the mean field

We discuss dynamical pairing correlations in the context of configuration mixing of projected self-consistent mean-field states, and the origin of a divergence that might appear when such calculations are done using an energy functional in the spirit of a naive generalized density functional theory.Comment: Proceedings of the XIII Nuclear Physics Workshop ``Maria and Pierre Curie'' on ``Pairing and beyond - 50 years of the BCS model'', held at Kazimierz Dolny, Poland, September 27 - October 1, 2006. Int. J. Mod. Phys. E, in prin

A simple parameter-free one-center model potential for an effective one-electron description of molecular hydrogen

For the description of an H2 molecule an effective one-electron model potential is proposed which is fully determined by the exact ionization potential of the H2 molecule. In order to test the model potential and examine its properties it is employed to determine excitation energies, transition moments, and oscillator strengths in a range of the internuclear distances, 0.8 < R < 2.5 a.u. In addition, it is used as a description of an H2 target in calculations of the cross sections for photoionization and for partial excitation in collisions with singly-charged ions. The comparison of the results obtained with the model potential with literature data for H2 molecules yields a good agreement and encourages therefore an extended usage of the potential in various other applications or in order to consider the importance of two-electron and anisotropy effects.Comment: 8 pages, 6 figure

Big consequences of small changes (Non-locality and non-linearity of Hartree-Fock equations)

It is demonstrated that non-locality and non-linearity of Hartree-Fock equations dramatically affect the properties of their solutions that essentially differ from solutions of Schr?dinger equation with a local potential. Namely, it acquires extra zeroes, has different coordinate asymptotic, violates so-called gauge-invariance, has different scattering phases at zero energy, has in some cases several solutions with the same set of quantum numbers, usually equivalent expressions of current and Green's functions became non-equivalent. These features result in a number of consequences for probabilities of some physical processes, leading e. g. to extra width of atomic Giant resonances and enhance considerably the ionization probability of inner atomic electrons by a strong field.Comment: 16 pages, 3 figure

Gradient Symplectic Algorithms for Solving the Radial Schrodinger Equation

The radial Schrodinger equation for a spherically symmetric potential can be regarded as a one dimensional classical harmonic oscillator with a time-dependent spring constant. For solving classical dynamics problems, symplectic integrators are well known for their excellent conservation properties. The class of {\it gradient} symplectic algorithms is particularly suited for solving harmonic oscillator dynamics. By use of Suzuki's rule for decomposing time-ordered operators, these algorithms can be easily applied to the Schrodinger equation. We demonstrate the power of this class of gradient algorithms by solving the spectrum of highly singular radial potentials using Killingbeck's method of backward Newton-Ralphson iterations.Comment: 19 pages, 10 figure

The Significance of Micas in Ancient Cross-bedded Sandstones

In our study of thin sections of the cross-bedded Coconino Sandstone we encountered muscovite as a trace mineral in almost every thin section of the hundreds that we cut. As we began to study other similar cross-bedded sandstones like the Tensleep, Lyons and Hopeman the same pattern began to emerge. All of these sandstones have been conventionally interpreted as desert wind-blown deposits. A novel set of experiments were performed and recently published by some Cedarville University geology students and the lead author of this paper (Anderson et al., 2017). They found when muscovite-rich quartz sand was experimentally placed into a simulated eolian setting, muscovite only survived for a matter of days. When muscovite-rich quartz sand was experimentally placed into a simulated subaqueous setting it was still present after a year of constant agitation before the experiment was finally terminated. Even though this was a simple experiment and only a limited number of trials were performed it confirms field observations by the authors that mica is rare in modern eolian deposits (unless they are very near a granitic source) and its relative abundance in beach and marine sands. The implications are significant. Although more experiments could be performed, the experiments and observations suggest that mica is rapidly degraded in wind-blown environments and survives when transported by water. Evidently water cushions the grain-to-grain collisions and prevents rapid deterioration of the muscovite in subaqueous settings. This proposed paper will catalog and illustrate the large number of cross-bedded sandstones we have found that contain mica (mostly muscovite) as an accessory mineral. The dominant conventional view is that these sandstones are eolian, but the presence of muscovite based on experimental data and field observations suggests otherwise. The presence of muscovite in cross-bedded sandstones can be used as one of many criteria to argue for subaqueous deposition

Symmetry of the Atomic Electron Density in Hartree, Hartree-Fock, and Density Functional Theory

The density of an atom in a state of well-defined angular momentum has a specific finite spherical harmonic content, without and with interactions. Approximate single-particle schemes, such as the Hartree, Hartree-Fock, and Local Density Approximations, generally violate this feature. We analyze, by means of perturbation theory, the degree of this violation and show that it is small. The correct symmetry of the density can be assured by a constrained-search formulation without significantly altering the calculated energies. We compare our procedure to the (different) common practice of spherically averaging the self-consistent potential. Kohn-Sham density functional theory with the exact exchange-correlation potential has the correct finite spherical harmonic content in its density; but the corresponding exact single particle potential and wavefunctions contain an infinite number of spherical harmonics.Comment: 11 pages, 6 figures. Expanded discussion of spherical harmonic expansion of Hartree density. Some typos corrected, references adde