12,052 research outputs found
Interferon-alpha 2b early phase chronic Lymphocytic Leukemia with high risk for progression-first results of a randomized multicenter AIO-Study
The reaction 13C(alpha,n)16O: a background for the observation of geo-neutrinos
The absolute cross section of the C(,n)O reaction has
been measured at E = 0.8 to 8.0 MeV with an overall accuracy of 4%.
The precision is needed to subtract reliably a background in the observation of
geo-neutrinos, e.g. in the KamLAND detector.Comment: LaTex file, 13 pages including 3 ps figures. Any request to
[email protected]. Phys. Rev . C, to appea
Polytopality and Cartesian products of graphs
We study the question of polytopality of graphs: when is a given graph the
graph of a polytope? We first review the known necessary conditions for a graph
to be polytopal, and we provide several families of graphs which satisfy all
these conditions, but which nonetheless are not graphs of polytopes. Our main
contribution concerns the polytopality of Cartesian products of non-polytopal
graphs. On the one hand, we show that products of simple polytopes are the only
simple polytopes whose graph is a product. On the other hand, we provide a
general method to construct (non-simple) polytopal products whose factors are
not polytopal.Comment: 21 pages, 10 figure
Origin of magnetic moments in defective TiO2 single crystals
In this paper we show that ferromagnetism can be induced in pure TiO2 single
crystals by oxygen ion irradiation. By combining x-ray diffraction,
Raman-scattering, and electron spin resonance spectroscopy, a defect complex,
\emph{i.e.} Ti ions on the substitutional sites accompanied by oxygen
vacancies, has been identified in irradiated TiO2. This kind of defect complex
results in a local (TiO) stretching Raman mode. We elucidate that
Ti ions with one unpaired 3d electron provide the local magnetic
moments.Comment: 4 pages, 4 figures, to be published at Phys. Rev.
Quantum Phase Diagram of Bosons in Optical Lattices
We work out two different analytical methods for calculating the boundary of
the Mott-insulator-superfluid (MI-SF) quantum phase transition for scalar
bosons in cubic optical lattices of arbitrary dimension at zero temperature
which improve upon the seminal mean-field result. The first one is a
variational method, which is inspired by variational perturbation theory,
whereas the second one is based on the field-theoretic concept of effective
potential. Within both analytical approaches we achieve a considerable
improvement of the location of the MI-SF quantum phase transition for the first
Mott lobe in excellent agreement with recent numerical results from Quantum
Monte-Carlo simulations in two and three dimensions. Thus, our analytical
results for the whole quantum phase diagram can be regarded as being
essentially exact for all practical purposes
The Star-Forming Dwarf Galaxy Populations of two z ~ 0.4 Clusters: MS1512.4+3647 and Abell 851
We present the results of a deep narrow-band [OII] 3727 \AA emission-line
search for faint ( 27), star-forming galaxies in the field of the
MS1512.4+3647 cluster. We find no evidence for an over-density of emission-line
sources relative to the field at 0.4 (Hogg et al. 1998), and therefore
conclude that the MS1512.4+3647 sample is dominated by field [OII]
emission-line galaxies which lie along the 180 Mpc line of sight
immediately in front and behind the cluster. This is surprising, given that the
previously surveyed cluster Abell 851 has 3-4 times the field
emission-line galaxy density (Martin et al. 2000). We find that the
MS1512.4+3647 sample is deficient in galaxies with intermediate colors (1.0 2.0) and implied star-formation exponential decay timescales
100 Myr - 1 Gyr that dominate the Abell 851 emission-line galaxy population.
Instead, the majority of [OII] emission-line galaxies surrounding the
MS1512.4+3647 cluster are blue () and forming stars in bursts
with 100 Myr. In both samples, galaxies with the shortest
star-formation timescales are preferentially among the faintest star-forming
objects. Their i luminosities are consistent with young stellar populations
\sim 10^8 - 10^9 \Msun, although an additional factor of ten in stellar mass
could be hiding in underlying old stellar populations. We discuss the
implications for the star-formation histories of dwarf galaxies in the field
and rich clusters.Comment: 26 pages, including 5 tables and 13 figures; accepted for publication
in the Astrophysical Journa
Breast cancer worry in higher-risk women offered preventive therapy: a UK multicentre prospective study
PURPOSE: Women's worry about developing breast cancer may influence their decision to use preventive therapy. However, the direction of this relationship has been questioned. We prospectively investigated the relationship between breast cancer worry and uptake of preventive therapy. The socio-demographic and clinical factors associated with high breast cancer worry were also investigated. METHODS: Women at increased risk of developing breast cancer were recruited from clinics across England (n = 408). Participants completed a survey on their breast cancer worry, socio-demographic and clinical factors. Uptake of tamoxifen was recorded at 3 months (n = 258 women, 63.2%). Both primary and sensitivity analyses were conducted using different classifications of low, medium and high worry. RESULTS: 39.5% of respondents reported medium breast cancer worry at baseline and 21.2% reported high worry. Ethnic minority women were more likely to report high worry than white women (OR = 3.02, 95%CI 1.02, 8.91, p = 0.046). Women educated below degree level were more likely to report high worry than those with higher education (OR = 2.29, 95%CI 1.28, 4.09, p = 0.005). No statistically significant association was observed between worry and uptake. In the primary analysis, fewer respondents with medium worry at baseline initiated tamoxifen (low worry = 15.5%, medium = 13.5%, high = 15.7%). In the sensitivity analysis, participants with medium worry reported the highest uptake of tamoxifen (19.7%). CONCLUSIONS: No association was observed between worry and uptake, although the relationship was affected by the categorisation of worry. Standardised reporting of the classification of worry is warranted to allow transparent comparisons across cohorts
Bose-Einstein Condensation in a Trap: the Case of a Dense Condensate
We consider the Bose-Einstein condensation of atoms in a trap where the
density of particles is so high that the low density approach of Gross and
Pitaevskii will not be applicable. For this purpose we use the slave boson
representation which is valid for hard-core bosons at any density. This
description leads to the same results as the Gross-Pitaevskii approach in the
low density limit, but for higher densities, it predicts the depletion of the
order parameter field condensate in the regions where the density of the atomic
cloud is high.Comment: 6 pages RevTeX, 3 eps-figure
Class II (DR) antigenexpression on CD8+ lymphocyte subsets in acquired immune deficiency syndrome (AIDS)
The Casimir Force in Randall Sundrum Models
We discuss and compare the effects of one extra dimension in the Randall
Sundrum models on the evaluation of the Casimir force between two parallel
plates. We impose the condition that the result reproduce the experimental
measurements within the known uncertainties in the force and the plate
separation, and get an upper bound kR < 20 if the curvature parameter k of
AdS_5 is equal to the Planck scale. Although the upper bound decreases as k
decreases, kR ~ 12, which is the required value for solving the hierarchy
problem, is consistent with the Casimir force measurements. For the case where
the 5th dimension is infinite, the correction to the Casimir force is very
small and negligible.Comment: 16 pages, 2 figures, references added, text improved, accepted for
publication in PR
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