1,371 research outputs found
A Schematic Model For Density-Dependent Vector Meson Masses
A schematic two-level model consisting of a "collective" bosonic state and an
"elementary" meson is constructed that provides interpolation from a hadronic
description (a la Rapp/Wambach) to B/R scaling for the description of
properties of vector mesons in dense medium. The development is based on a
close analogy to the degenerate schematic model of Brown for giant resonances
in nuclei.Comment: 20 pages, latex with 8 figures: Talk given by GEB at AIP Klaus
Kinder-Geiger Memorial Meeting, 3 October 199
Palliative Urinary Diversion in Adenocarcinoma of the Prostate
Ten patients with inoperable prostatic carcinoma, producing ureteral obstruction and azotemia, underwent palliative urinary diversion. Good quality survivals of two months to three years were obtained. These results compare favorably with the good results seer) In gynecologic neoplasm of the bladder, colon and breast. In selected cases of carcinoma of the prostate, palliative urinary diversion is indicated when the prospects exist for further benefit from chemotherapy or radiotherapy
A cross-cultural re-evaluation of the Exercise Addiction Inventory (EAI) in five countries
Research into the detrimental effects of excessive exercise has been conceptualized in a number of similar ways, including ‘exercise addiction’ , ‘exercise dependence’ , ‘obligatory exercising’, ‘exercise abuse’, and ‘compulsive exercise’. Among the most currently used (and psychometrically valid and reliable) instruments is the Exercise Addiction Inventory (EAI). The present study aimed to further explore the psychometric properties of the EAI by combining the datasets of a number of surveys carried out in five different countries (Denmark, Hungary, Spain, UK, and US) that have used the EAI with a total sample size of 6,031 participants. A series of multigroup confirmatory factor analyses (CFAs) were carried out examining configural invariance, metric invariance, and scalar invariance. The CFAs using the combined dataset supported the configural invariance and metric invariance but not scalar invariance. Therefore, EAI factor scores from five countries are not comparable because the use or interpretation of the scale was different in the five nations. However, the covariates of exercise addiction can be studied from a cross-cultural perspective because of the metric invariance of the scale. Gender differences among exercisers in the interpretation of the scale also emerged. The implications of the results are discussed, and it is concluded that the study’s findings will facilitate a more robust and reliable use of the EAI in future research
Crystallization of the regulatory and effector domains of the key sporulation response regulator Spo0A
The key response-regulator gene of sporulation, spo0A, has been cloned from Bacillus stearothermophilus and the encoded protein purified. The DNA-binding and phospho-acceptor domains of Spo0A have been prepared by tryptic digestion of the intact protein and subsequently crystallized in forms suitable for X-ray crystallographic studies. The DNA-binding domain has been crystallized in two forms, one of which diffracts X-rays to beyond 2.5 Angstrom spacing. The crystals of the phospho-acceptor domain diffract X-rays beyond 2.0 Angstrom spacing using synchrotron radiation
Mesons and nucleons from holographic QCD in a unified approach
We investigate masses and coupling constants of mesons and nucleons within a
hard wall model of holographic QCD in a unified approach. We first examine an
appropriate form of fermionic solutions by restricting the mass coupling for
the five dimensional bulk fermions and bosons. We then derive approximated
analytic solutions for the nucleons and the corresponding masses in a small
mass coupling region. In order to treat meson and nucleon properties on the
same footing, we introduce the same infrared (IR) cut in such a way that the
meson-nucleon coupling constants, i.e., g_{pi NN} and g_{rho NN} are uniquely
determined. The first order approximation with respect to a dimensionless
expansion parameter, which is valid in the small mass coupling region,
explicitly shows difficulties to avoid the IR scale problem of the hard wall
model. We discuss possible ways of circumventing these problems.Comment: 15 pages, No figure. Several typos have been remove
Renormalization Group Analysis of \rho-Meson Properties at Finite Density
We calculate the density dependence of the -meson mass and coupling
constant() for -nucleon-nucleon vertex at one loop using the
lagrangian where the -meson is included as a dynamical gauge boson of a
hidden local symmetry. From the condition that thermodynamic potential should
not depend on the arbitrary energy scale, renormalization scale, one can
construct a renormalization group equation for the thermodynamic potential and
argue that the various renormalization group coefficients are functions of the
density or temperature. We calculate the -function for
-nucleon-nucleon coupling constant () and -function
for -meson mass (). We found that the -meson mass
and the coupling constant for drop as density increases in the
low energy limit.Comment: 24 pages, 10 figures, revised versio
Finite-Temperature Corrections in the Dilated Chiral Quark Model
We calculate the finite-temperature corrections in the dilated chiral quark
model using the effective potential formalism. Assuming that the dilaton limit
is applicable at some short length scale, we interpret the results to represent
the behavior of hadrons in dense {\it and} hot matter. We obtain the scaling
law, while we argue, using PCAC, that
pion mass does not scale within the temperature range involved in our
Lagrangian. It is found that the hadron masses and the pion decay constant drop
faster with temperature in the dilated chiral quark model than in the
conventional linear sigma model that does not take into account the QCD scale
anomaly. We attribute the difference in scaling in heat bath to the effect of
baryonic medium on thermal properties of the hadrons. Our finding would imply
that the AGS experiments (dense {\it and} hot matter) and the RHIC experiments
(hot and dilute matter) will ``see" different hadron properties in the
hadronization phase.Comment: 13 pages , LaTe
- …