1,111 research outputs found
Immunocytochemical localisation of follicle stimulating hormone (FSH) in normal, benign and malignant human prostates.
Immunocytochemical localisation of follicle stimulating hormone (FSH) was carried out in normal, benign and malignant human prostates by indirect immunoperoxidase technique. Positive staining was observed in the epithelial cells of all the three categories, while the stromal cells showed a weakly positive reaction in a few specimens. The brown reaction product was dispersed in the cytoplasm of the epithelial cells. These observations demonstrate the presence of immunoreactive FSH-like peptide in human prostate. The significance of FSH in the aetiopathology of prostatic disorders is discussed
Studies on immunocytochemical localization of inhibin-like material in human prostatic tissue: comparison of its distribution in normal, benign and malignant prostates.
A specific antiserum has been generated against inhibin-like material (ILM) of prostatic origin. Using the immunoperoxidase technique, localization of ILM has been examined in a total of 114 prostates including normal (4 specimens), malignant (46) and hyperplastic (55) tissues. ILM positive immunocytochemical reactions were confined to the cytoplasm and not the nucleus of the prostatic acinar cells in the three categories of prostate, whereas the stroma showed negative reactions. The intensity of positive reactions decreased in the following order: Hyperplasia, incidental and moderately differentiated carcinomas, poorly differentiated carcinomas, whereas metaplasia and granulomatous prostatitis gave negative reactions for ILM. Using this experimental protocol, 200 non-prostatic tissue were found to be completely negative, demonstrating the specificity of the test for prostatic epithelium. These findings indicate a potential use of ILM as a marker of prostatic tissue
An excursion set model of the cosmic web: The abundance of sheets, filaments and halos
We discuss an analytic approach for modeling structure formation in sheets,
filaments and knots. This is accomplished by combining models of triaxial
collapse with the excursion set approach: sheets are defined as objects which
have collapsed along only one axis, filaments have collapsed along two axes,
and halos are objects in which triaxial collapse is complete. In the simplest
version of this approach, which we develop here, large scale structure shows a
clear hierarchy of morphologies: the mass in large-scale sheets is partitioned
up among lower mass filaments, which themselves are made-up of still lower mass
halos. Our approach provides analytic estimates of the mass fraction in sheets,
filaments and halos, and its evolution, for any background cosmological model
and any initial fluctuation spectrum. In the currently popular CDM
model, our analysis suggests that more than 99% of the cosmic mass is in
sheets, and 72% in filaments, with mass larger than at the
present time. For halos, this number is only 46%. Our approach also provides
analytic estimates of how halo abundances at any given time correlate with the
morphology of the surrounding large-scale structure, and how halo evolution
correlates with the morphology of large scale structure.Comment: 22 pages, 7 figures, Accepted for publication in Ap
Power law correlations in galaxy distribution and finite volume effects from the Sloan Digital Sky Survey Data Release Four
We discuss the estimation of galaxy correlation properties in several volume
limited samples, in different sky regions, obtained from the Fourth Data
Release of the Sloan Digital Sky Survey. The small scale properties are
characterized through the determination of the nearest neighbor probability
distribution. By using a very conservative statistical analysis, in the range
of scales [0.5,~30] Mpc/h we detect power-law correlations in the conditional
density in redshift space, with an exponent \gamma=1.0 \pm 0.1. This behavior
is stable in all different samples we considered thus it does not depend on
galaxy luminosity. In the range of scales [~30,~100] Mpc/h we find evidences
for systematic unaveraged fluctuations and we discuss in detail the problems
induced by finite volume effects on the determination of the conditional
density. We conclude that in such range of scales there is an evidence for a
smaller power-law index of the conditional density. However we cannot
distinguish between two possibilities: (i) that a crossover to homogeneity
(corresponding to \gamma=0 in the conditional density) occurs before 100 Mpc/h,
(ii) that correlations extend to scales of order 100 Mpc/h (with a smaller
exponent 0 < \gamma <1). We emphasize that galaxy distributions in these
samples present large fluctuations at the largest scales probed, corresponding
to the presence of large scale structures extending up to the boundaries of the
present survey. Finally we discuss several differences between the behavior of
the conditional density in mock galaxy catalogs built from cosmological N-body
simulations and real data. We discuss some theoretical implications of such a
fact considering also the super-homogeneous features of primordial density
fields.Comment: 13 pages, 19 figures, to be publsihed in Astronomy and Astrophysic
On Local Approximations to the Nonlinear Evolution of Large-Scale Structure
We present a comparative analysis of several methods, known as local
Lagrangian approximations, which are aimed to the description of the nonlinear
evolution of large-scale structure. We have investigated various aspects of
these approximations, such as the evolution of a homogeneous ellipsoid,
collapse time as a function of initial conditions, and asymptotic behavior. As
one of the common features of the local approximations, we found that the
calculated collapse time decreases asymptotically with the inverse of the
initial shear. Using these approximations, we have computed the cosmological
mass function, finding reasonable agreement with N-body simulations and the
Press-Schechter formula.Comment: revised version with color figures, minor changes, accepted for
publication in the Astrophysical Journal, 30 pages, 13 figure
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