Signal amplification by combining two advanced immunohistochemical techniques

The immunohistochemical techniques known as EnVision™+ System (EVS) and Mirror Image Complementary Antibody (MICA) were recently introduced into laboratory practice because of their high sensitivity. In this paper these techniques were compared and their sequences combined to obtain a new method possibly more sensitive than the original ones. The immunohistochemical staining employing the avidin-biotin complex (ABC), largely used as routine, was adopted as a term of comparison. Samples from the small and large intestine of pigs and sheep were fixed in Bouin and embedded in Paraplast. The primary antibodies utilized were directed against the neuronal nitric oxide synthase (nNOS), vasoactive intestinal polypeptide (VIP) and chromogranin A (Cr A). Targets of these antibodies were nerve structures of the intestinal wall, as well as endocrine cells scattered in the mucosa of the bowel, defined neuroendocrine cells or paraneurons. The EVS method appeared as slightly superior to the MICA method regarding sensitivity of detection. The EVS/MICA (combined) method resulted four/eight times more effective than the original techniques regarding sensitivity of detection and staining intensity, both at low and high dilutions of the primary antibodies. Of these latter, immunopositive structures were still clearly identifiable, at a dilution of 1:256,000. Such efficiency could be explained by the high number of revealing molecules of peroxidase contained in the new sequence. The application of the combined method is recommended when a small quantity of tissue antigens needs to be detected immunohistochemically

Condensation of vortices and disorder parameter in 3d Heisenberg model

The 3d Heisenberg model is studied from a dual point of view. It is shown that the disordered phase corresponds to condensation of vortices in the vacuum, and the critical indices are computed from the corresponding disorder parameter.Comment: LATTICE98(spin

A disorder analysis of the Ising model

Lattice studies of monopole condensation in QCD are based on the construction of a disorder parameter, a creation operator of monopoles which is written in terms of the gauge fields. This procedure is expected to work for any system which presents duality. We check it on the Ising model in 2d, which is exactly solvable. The output is an amusing exercise in statistical mechanics.Comment: 14 pages, 3 figure

Isoforms of Nitric Oxide Synthase in the Pig Testis

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Condensation of vortices in the X-Y model in 3d: a disorder parameter

A disorder parameter is constructed which signals the condensation of vortices. The construction is tested by numerical simulations.Comment: 9 pages, 5 postscript figures, typset using REVTE

A disorder parameter for dual superconductivity in gauge theories

Dual superconductivity in the confining phase of gauge theories is discussed in terms of a disorder parameter which vanishes in normal phase and is different from zero in the superconducting phase.Comment: 3 pages, 4 postscript figures, espcrc2, epsfig latex styles, Contribution to Lat 97 Conference, Edinburg

Confinement in QCD

The guiding lines of lattice investigations on colour confinement are reviewed, together with recent results.Comment: 7 pages,3 figures, Plenary talk at PANIC'99,10-16 June 1999,Uppsal

An Order Parameter Reconciling Abelian and Center Dominance in SU(2) Yang-Mills Theory

We analyze previously proposed order parameters for the confinement - deconfinement transition in lattice SU(2) Yang-Mills theory, defined as vacuum expectation value (v.e.v.) of monopole fields in abelian projection gauges. We show that they exhibit some inconsistency in the treatment of small scales, due to a violation of Dirac quantization condition for fluxes. We propose a new order parameter avoiding this inconsistency. It can be interpreted as v.e.v. of the field of a regular monopole in any abelian projection gauge, but it is independent of the choice of the abelian projection. Furthermore, being constructed in terms of surfaces of center vortices, it has also a natural interpretation in the approach of center dominance.Comment: TeX file, 31 page