1,512 research outputs found
Centrality dependence of the multiplicity and transverse momentum distributions at RHIC and LHC and the percolation of strings
The dependence of the multiplicity and the transverse momentum distribution
on the number of collisions are studied for central and peripheral Au-Au
collisions at SPS, RHIC and LHC energies in the framework of percolation of
strings. A scaling law relating the multiplicity to the mean transverse
momentum is obtained. Our results are in overall agreement with the SPS and
RHIC data, obtaining a suppression on distribution even for larger
than 1 GeV/c.Comment: Contribution to QM2002, espcrc1.st
p53 overexpression is a predictor of local recurrence after treatment for both in situ and invasive ductal carcinoma of the breast
Background. Several biological markers have been related to prognosis in mammary ductal carcinoma. The aim of the study was to determine biological markers that could predict local recurrence following treatment for all stages of primary operable ductal carcinoma of the breast. Materials and methods. A consecutive series of patients treated for pure ductal carcinoma in situ (DCIS, n = 110) and invasive ductal carcinoma (IDC, n = 243) was studied. Twenty-three patients with DCIS were excluded because of lack of original paraffin embedded tissue. All patients had been treated between July 1996 and December 2001. Median follow-up was 49.8 mo. From the original paraffin embedded tumors, tissue microarrays (TMAs) were constructed. On these TMAs, immunohistochemistry was performed for estrogen-receptor (ER), progesterone-receptor (PR), Her2/neu, p53, and cyclin D1. Main outcome was the event of LR. All analyses were stratified for diagnosis (DCIS or IDC) and pathological grade. Results. In univariate analyses, Her2/neu overexpression (hazard ratio [HR] 3.1, 95% confidence interval [CI] 1.1-8.7, P = 0.032) and p53 overexpression (HR 3.5, 95% Cl 1.3-9.3, P = 0.014) were associated with LR in patients treated for both DCIS and IDC. In multivariate analysis, p53 overexpression (HR 3.0, 95% CI 1.1-8.2, P = 0.036 and HR 4.4,95% Cl 1.5-12.9, P = 0.008) and adjuvant radiotherapy (HR 0.2, 95% Cl 0.1-0.8, P = 0.026) were independent common predictors of LR in patients who had received treatment for both DCIS and IDC. Conclusions. p53 overexpression is a common predictor of LR following treatment for all stages of primary operable ductal carcinoma of the breast. This marker may help in planning optimal treatment and follow-up. (C) 2007 Elsevier Inc. All rights reserved
On the equivalence between 2D Yukawa and Gross-Neveu models
We study numerically on the lattice the 2D Yukawa model with the U(1) chiral
symmetry and = 16 at infinite scalar field self-coupling. The scaling
behaviour of the fermion mass, as the Yukawa coupling approaches zero, is
analysed using the mean field method. It is found to agree with that of the
Gross-Neveu model with the same symmetry and . The results suggest that
the 2D Yukawa models belong to the universality class of the Gross-Neveu models
not only at weak scalar field self-coupling but also for a broad range of the
bare parameters which is not accessible to the expansion. New
universality classes might arise at the crossover to the spin model
universality class, however.Comment: 18 pages, Juelich HLRZ 111/9
Nonrelativistic Factorizable Scattering Theory of Multicomponent Calogero-Sutherland Model
We relate two integrable models in (1+1) dimensions, namely, multicomponent
Calogero-Sutherland model with particles and antiparticles interacting via the
hyperbolic potential and the nonrelativistic factorizable -matrix theory
with -invariance. We find complete solutions of the Yang-Baxter
equations without implementing the crossing symmetry, and one of them is
identified with the scattering amplitudes derived from the Schr\"{o}dinger
equation of the Calogero-Sutherland model. This particular solution is of
interest in that it cannot be obtained as a nonrelativistic limit of any known
relativistic solutions of the -invariant Yang-Baxter equations.Comment: 4 pages, latex(uses Revtex), one figur
Anemia crônica normovolêmica (acn) reduzindo a lipoperoxidação de coração e estômago de ratos
Resultant pressure distribution pattern along the basilar membrane in the spiral shaped cochlea
Cochlea is an important auditory organ in the inner ear. In most mammals, it
is coiled as a spiral. Whether this specific shape influences hearing is still
an open problem. By employing a three dimensional fluid model of the cochlea
with an idealized geometry, the influence of the spiral geometry of the cochlea
is examined. We obtain solutions of the model through a conformal
transformation in a long-wave approximation. Our results show that the net
pressure acting on the basilar membrane is not uniform along its spanwise
direction. Also, it is shown that the location of the maximum of the spanwise
pressure difference in the axial direction has a mode dependence. In the
simplest pattern, the present result is consistent with the previous theory
based on the WKB-like approximation [D. Manoussaki, Phys. Rev. Lett. 96,
088701(2006)]. In this mode, the pressure difference in the spanwise direction
is a monotonic function of the distance from the apex and the normal velocity
across the channel width is zero. Thus in the lowest order approximation, we
can neglect the existance of the Reissner's membrane in the upper channel.
However, higher responsive modes show different behavior and, thus, the real
maximum is expected to be located not exactly at the apex, but at a position
determined by the spiral geometry of the cochlea and the width of the cochlear
duct. In these modes, the spanwise normal velocities are not zero. Thus, it
indicates that one should take into account of the detailed geometry of the
cochlear duct for a more quantitative result. The present result clearly
demonstrates that not only the spiral geometry, but also the geometry of the
cochlear duct play decisive roles in distributing the wave energy.Comment: 21 pages. (to appear in J. Biol. Phys.
SPIDER: Probing the Early Universe with a Suborbital Polarimeter
We evaluate the ability of SPIDER, a balloon-borne polarimeter, to detect a
divergence-free polarization pattern ("B-modes") in the Cosmic Microwave
Background (CMB). In the inflationary scenario, the amplitude of this signal is
proportional to that of the primordial scalar perturbations through the
tensor-to-scalar ratio r. We show that the expected level of systematic error
in the SPIDER instrument is significantly below the amplitude of an interesting
cosmological signal with r=0.03. We present a scanning strategy that enables us
to minimize uncertainty in the reconstruction of the Stokes parameters used to
characterize the CMB, while accessing a relatively wide range of angular
scales. Evaluating the amplitude of the polarized Galactic emission in the
SPIDER field, we conclude that the polarized emission from interstellar dust is
as bright or brighter than the cosmological signal at all SPIDER frequencies
(90 GHz, 150 GHz, and 280 GHz), a situation similar to that found in the
"Southern Hole." We show that two ~20-day flights of the SPIDER instrument can
constrain the amplitude of the B-mode signal to r<0.03 (99% CL) even when
foreground contamination is taken into account. In the absence of foregrounds,
the same limit can be reached after one 20-day flight.Comment: 29 pages, 8 figures, 4 tables; v2: matches published version, flight
schedule updated, two typos fixed in Table 2, references and minor
clarifications added, results unchange
PHP48 COST SENSITIVENESS AND PHYSICIAN TREATMENT CHOICES
Objectives To explore the relationship between nodule count and lung cancer probability in baseline low-dose CT lung cancer screening. Materials and Methods Included were participants from the NELSON trial with at least one baseline nodule (3392 participants [45% of screen-group], 7258 nodules). We determined nodule count per participant. Malignancy was confirmed by histology. Nodules not diagnosed as screen-detected or interval cancer until the end of the fourth screening round were regarded as benign. We compared lung cancer probability per nodule count category. Results 1746 (51.5%) participants had one nodule, 800 (23.6%) had two nodules, 354 (10.4%) had three nodules, 191 (5.6%) had four nodules, and 301 (8.9%) had > 4 nodules. Lung cancer in a baseline nodule was diagnosed in 134 participants (139 cancers; 4.0%). Median nodule count in participants with only benign nodules was 1 (Inter-quartile range [IQR]: 1–2), and 2 (IQR 1–3) in participants with lung cancer (p = NS). At baseline, malignancy was detected mostly in the largest nodule (64/66 cancers). Lung cancer probability was 62/1746 (3.6%) in case a participant had one nodule, 33/800 (4.1%) for two nodules, 17/354 (4.8%) for three nodules, 12/191 (6.3%) for four nodules and 10/301 (3.3%) for > 4 nodules (p = NS). Conclusion In baseline lung cancer CT screening, half of participants with lung nodules have more than one nodule. Lung cancer probability does not significantly change with the number of nodules. Baseline nodule count will not help to differentiate between benign and malignant nodules. Each nodule found in lung cancer screening should be assessed separately independent of the presence of other nodules
Search for DCC in 158A GeV Pb+Pb Collisions
A detailed analysis of the phase space distributions of charged particles and
photons have been carried out using two independent methods. The results
indicate the presence of nonstatistical fluctuations in localized regions of
phase space.Comment: Talk at the PANIC99 Conference, June 9-16, 199
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