Smooth Random Surfaces from Tight Immersions?

We investigate actions for dynamically triangulated random surfaces that consist of a gaussian or area term plus the {\it modulus} of the gaussian curvature and compare their behavior with both gaussian plus extrinsic curvature and ``Steiner'' actions.Comment: 7 page

An Effective Model for Crumpling in Two Dimensions?

We investigate the crumpling transition for a dynamically triangulated random surface embedded in two dimensions using an effective model in which the disordering effect of the $X$ variables on the correlations of the normals is replaced by a long-range ``antiferromagnetic'' term. We compare the results from a Monte Carlo simulation with those obtained for the standard action which retains the $X$'s and discuss the nature of the phase transition.Comment: 5 page

Observations on the mammalian tests

This thesis deals with some aspects of the histology, histochemistry, and ultrastructure of the mammalian testis during development and under experimental conditions. In the interstitium of the foetal sheep testis three types of Leydig cells are discernible. The commonest contains PAS positive granules, probably glycoprotein, and Sudanophilic lipids. Schiff positive lipids are absent from these cells. Two rarer, atypical forms of interstitial cell exist. The first has groups of eosinophil granules in its cytoplasm; and second is shrunken and possesses a pycnotio nucleus. The fate of the cells containing eosinophil granules is not clear, and the cells possessing pycnotic nuclei are clearly in the process of degeneration. The Leydig cell of the growing mouse, in common with those of other homiothermal vertebrates contains glycoprotein. In contrast to the Leydig cell of poikilotherms it has no glycogen. The mouse Leydig cell has Sudanophilic lipids. Lipids stainable with 2-4 dinitrophenyl hydrazine and Schiff's reagent are absent from the neonatal Leydig cell, present in large quantities in the prepubertal Leydig cell, and present in reduced amounts in the adult cell. Cytomorphosis of the Leydig cell from its mesenchymal precursor includes the acquisition of Sudanophilic lipids, and mitochondria. Graphic representation of the growth rates of the Leydig tissue in seminal vesicles shows that both tissues grow at a similar rate, and that the growth of the Leydig tissue antedates the growth of the seminal vesicles. Mitotic figures have been demonstrated in typical Leydig cells. The actual volume of the Leydig tissue during the prepubertal phase increases at a compound rate of about fifteen per cent per day. The Leydig mitotic rate is 63% per day. The increment in Leydig tissue volume is thus due to cell division, plus recruitment from mesenchyma. Leydig cells in the adult testis do not appear to undergo mitosis in normal circumstances. From those facts it is plain that the concept of separate foetal and pubertal generations of Leydig cells is based on inadequate histological methods for demonstrating' the relatively slowly growing Leydig tissue in a rapidly expanding prepubertal testis. (Abstract shortened by ProQuest.)

Monte Carlo Renormalization of the 3-D Ising model: Analyticity and Convergence

We review the assumptions on which the Monte Carlo renormalization technique is based, in particular the analyticity of the block spin transformations. On this basis, we select an optimized Kadanoff blocking rule in combination with the simulation of a d=3 Ising model with reduced corrections to scaling. This is achieved by including interactions with second and third neighbors. As a consequence of the improved analyticity properties, this Monte Carlo renormalization method yields a fast convergence and a high accuracy. The results for the critical exponents are y_H=2.481(1) and y_T=1.585(3).Comment: RevTeX, 4 PostScript file

Comments on Sweeny and Gliozzi dynamics for simulations of Potts models in the Fortuin-Kasteleyn representation

We compare the correlation times of the Sweeny and Gliozzi dynamics for two-dimensional Ising and three-state Potts models, and the three-dimensional Ising model for the simulations in the percolation prepresentation. The results are also compared with Swendsen-Wang and Wolff cluster dynamics. It is found that Sweeny and Gliozzi dynamics have essentially the same dynamical critical behavior. Contrary to Gliozzi's claim (cond-mat/0201285), the Gliozzi dynamics has critical slowing down comparable to that of other cluster methods. For the two-dimensional Ising model, both Sweeny and Gliozzi dynamics give good fits to logarithmic size dependences; for two-dimensional three-state Potts model, their dynamical critical exponent z is 0.49(1); the three-dimensional Ising model has z = 0.37(2).Comment: RevTeX, 4 pages, 5 figure

Beam spin asymmetries in deeply virtual Compton scattering (DVCS) with CLAS at 4.8 GeV

We report measurements of the beam spin asymmetry in deeply virtual Compton scattering (DVCS) at an electron beam energy of 4.8 GeV using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The DVCS beam spin asymmetry has been measured in a wide range of kinematics, 1.0 \u3c Q(2) \u3c 2.8 (GeV/c)(2), 0.12 \u3c x(B) \u3c 0.48, and 0.1 \u3c -t \u3c 0.8 (GeV/c)(2), using the reaction (e) over right arrow - \u3e e\u27pX. The number of H(e, e\u27gamma p) and H(e, e\u27pi(0)p) events are separated in each (Q(2), x(B), t) bin by a fit to the line shape of the H(e, e\u27p) X M(x)(2) distribution. The validity of the method was studied in detail using experimental and simulated data. It was shown that with the achieved missing mass squared resolution and the available statistics, the separation of DVCS-Bethe-Heitler and pi(0) events can reliably be done with less than 5% uncertainty. Also, the Q(2) and t dependences of the sin phi moments of the asymmetry are extracted and compared with theoretical calculations

Cluster variation - Pade` approximants method for the simple cubic Ising model

The cluster variation - Pade` approximant method is a recently proposed tool, based on the extrapolation of low/high temperature results obtained with the cluster variation method, for the determination of critical parameters in Ising-like models. Here the method is applied to the three-dimensional simple cubic Ising model, and new results, obtained with an 18-site basic cluster, are reported. Other techniques for extracting non-classical critical exponents are also applied and their results compared with those by the cluster variation - Pade` approximant method.Comment: 8 RevTeX pages, 3 PostScript figure

On the Stability of the Mean-Field Glass Broken Phase under Non-Hamiltonian Perturbations

We study the dynamics of the SK model modified by a small non-hamiltonian perturbation. We study aging, and we find that on the time scales investigated by our numerical simulations it survives a small perturbation (and is destroyed by a large one). If we assume we are observing a transient behavior the scaling of correlation times versus the asymmetry strength is not compatible with the one expected for the spherical model. We discuss the slow power law decay of observable quantities to equilibrium, and we show that for small perturbations power like decay is preserved. We also discuss the asymptotically large time region on small lattices.Comment: 34 page