Immunocytochemical localization of the main intrinsic polypeptide (MIP) in ultrathin frozen sections of rat lens.

The in situ distribution of the 26-kdalton Main Intrinsic Polypeptide (MIP or MP 26), a putative gap junction protein in ocular lens fibers, was defined at the electron microscope level using indirect immunoferritin labeling of ultrathin frozen sections of rat lens. MIP was found distributed throughout the plasma membrane of the lens fiber cell, with no apparent distinction between junctional and nonjunctional membrane. MIP was not detectable in the basal or lateral plasma membrane of the lens epithelial cell, including the interepithelial cell gap junctions; nor was MIP detectable in the plasma membrane or gap junctions of the hepatocyte. Previous reports have indicated that the protein composition of the lens fiber cell junction differs from that of the hepatocyte gap junction. The evidence presented here suggests that the composition of the fiber cell junction and plasma membrane is also immunocytochemically distinct from that of its progenitor, the lens epithelial cell

Hall effect in the normal state of high Tc cuprates

We propose a model for explaining the dependence in temperature of the Hall effect of high Tc cuprates in the normal state in various materials. They all show common features: a decrease of the Hall coefficient RH with temperature and a universal law, when plotting RH(T)/RH(T0) versus T/T0, where T0 is defined from experimental results. This behaviour is explained by using the well known electronic band structure of the CuO2 plane, showing saddle points at the energies ES in the directions (0,+/-pi) and (+/-pi,0). We remark that in a magnetic field, for energies E>ES the carrier orbits are hole-like and for E<ES they are electron-like, giving opposite contributions to RH. We are abble to fit the experimental results for a wide range of hole doping, and to fit the universal curve. For us kb*T0 is simply EF-ES, where EF is the Fermi level varying with the doping.Comment: 7 pages, 11 figure

Phase transition between d-wave and anisotropic s-wave gaps in high temperature oxides superconductors

We study models for superconductivity with two interactions: $V^>$ due to antiferromagnetic(AF) fluctuations and $V^<$ due to phonons, in a weak coupling approach to the high temperature superconductivity. The nature of the two interactions are considerably different; $V^>$ is positive and sharply peaked at ($\pm\pi$,$\pm\pi$) while $V^<$ is negative and peaked at ($0,0$) due to weak phonon screening. We numerically find (a) weak BCS attraction is enough to have high critical temperature if a van Hove anomaly is at work, (b) $V^>$ (AF) is important to give d-wave superconductivity, (c) the gap order parameter $\Delta({\bf k})$ is constant(s-wave) at extremely overdope region and it changes to anisotropic s-wave as doping is reduced, (d) there exists a first order phase transition between d-wave and anisotropic s-wave gaps. These results are qualitatively in agreement with preceding works; they should be modified in the strongly underdope region by the presence of antiferromagnetic fluctuations and ensuing AF pseudogap.Comment: 4 pages in RevTex (double column), 4 figure

The Painting Industries of Antwerp and Amsterdam, 1500−1700: A Data Perspective

This study presents a data driven comparative analysis of the painting industries in sixteenth and seventeenth century Antwerp and Amsterdam. The popular view of the development of these two artistic centers still holds that Antwerp flourished in the sixteenth century and was succeeded by Amsterdam after the former&rsquo;s recapturing by the Spanish in 1585. However, a demographic analysis of the number of painters active in Antwerp and Amsterdam shows that Antwerp recovered relatively quickly after 1585 and that it remained the leading artistic center in the Low Countries, only to be surpassed by Amsterdam in the 1650&rsquo;s. An analysis of migration patterns and social networks shows that painters in Antwerp formed a more cohesive group than painters in Amsterdam. As a result, the two cities responded quite differently to internal and external market shocks. Data for this study are taken from ECARTICO, a database and a linked data web resource containing structured biographical data on over 9100 painters working in the Low Countries until circa 1725