215 research outputs found
The Updated Zwicky Catalog (UZC)
The Zwicky Catalog of galaxies (ZC), with m_Zw<=15.5mag, has been the basis
for the Center for Astrophysics (CfA) redshift surveys. To date, analyses of
the ZC and redshift surveys based on it have relied on heterogeneous sets of
galaxy coordinates and redshifts. Here we correct some of the inadequacies of
previous catalogs by providing: (1) coordinates with <~2 arcsec errors for all
of the Nuzc catalog galaxies, (2) homogeneously estimated redshifts for the
majority (98%) of the data taken at the CfA (14,632 spectra), and (3) an
estimate of the remaining "blunder" rate for both the CfA redshifts and for
those compiled from the literature. For the reanalyzed CfA data we include a
calibrated, uniformly determined error and an indication of the presence of
emission lines in each spectrum. We provide redshifts for 7,257 galaxies in the
CfA2 redshift survey not previously published; for another 5,625 CfA redshifts
we list the remeasured or uniformly re-reduced value. Among our new
measurements, Nmul are members of UZC "multiplets" associated with the original
Zwicky catalog position in the coordinate range where the catalog is 98%
complete. These multiplets provide new candidates for examination of tidal
interactions among galaxies. All of the new redshifts correspond to UZC
galaxies with properties recorded in the CfA redshift compilation known as
ZCAT. About 1,000 of our new measurements were motivated either by inadequate
signal-to-noise in the original spectrum or by an ambiguous identification of
the galaxy associated with a ZCAT redshift. The redshift catalog we include
here is ~96% complete to m_Zw<=15.5, and ~98% complete (12,925 galaxies out of
a total of 13,150) for the RA(1950) ranges [20h--4h] and [8h--17h] and
DEC(1950) range [-2.5d--50d]. (abridged)Comment: 34 pp, 7 figs, PASP 1999, 111, 43
Feynman scaling violation on baryon spectra in pp collisions at LHC and cosmic ray energies
A significant asymmetry in baryon/antibaryon yields in the central region of
high energy collisions is observed when the initial state has non-zero baryon
charge. This asymmetry is connected with the possibility of baryon charge
diffusion in rapidity space. Such a diffusion should decrease the baryon charge
in the fragmentation region and translate into the corresponding decrease of
the multiplicity of leading baryons. As a result, a new mechanism for Feynman
scaling violation in the fragmentation region is obtained. Another numerically
more significant reason for the Feynman scaling violation comes from the fact
that the average number of cutted Pomerons increases with initial energy. We
present the quantitative predictions of the Quark-Gluon String Model (QGSM) for
the Feynman scaling violation at LHC energies and at even higher energies that
can be important for cosmic ray physics.Comment: 21 pages, 11 figures, and 1 table. arXiv admin note: substantial text
overlap with arXiv:1107.1615, arXiv:1007.320
Production of Secondaries in High Energy d+Au Collisions
In the framework of Quark-Gluon String Model we calculate the inclusive
spectra of secondaries produced in d+Au collisions at intermediate (CERN SPS)
and at much higher (RHIC) energies. The results of numerical calculations at
intermediate energies are in reasonable agreement with the data. At RHIC
energies numerically large inelastic screening corrections (percolation
effects) should be accounted for in calculations. We extract these effects from
the existing RHIC experimental data on minimum bias and central d+Au
collisions. The predictions for p+Au interactions at LHC energy are also given.Comment: 18 pages and 10 figure
Quark-Gluon String Model Description of Baryon Production in K^{\pm}N Interactions
The process of baryon production in K p collisions at high energies is
considered in the framework of the Quark-Gluon String Model. The contribution
of the string-junction mechanism to the strange baryon production is analysed.
The results of numerical calculations are in reasonable agreement with the data
on inclusive spectra of p, Lambda, bar{Lambda}, and on the bar{Lambda}/Lambda
asymmetry. The predictions for Xi and Omega baryons are presented.Comment: 19 pages, 7 figure
Options for Scaling up Community-Based Health Insurance for Rural Communities in Armenia
This paper summarises the results of a study which examined international experience with regard to community-based health financing (CBHF) schemes, scaling up CBHF schemes, and the feasibility of scaling up community-based health insurance (CBHI) in Armenia. It was based on a literature review of international experience and qualitative research in Armenia. The recommendations derived from this study have relevance both for Armenia and for the use of CBHI schemes as a tool for promoting pro-poor health system reform in low-resource settings more generally
Tetraquarks and Pentaquarks in String Models
We consider the production and decay of multiquark systems in the framework
of string models where the hadron structure is determined by valence quarks
together with string junctions. We show that the low mass multiquark resonances
can be very narrow.Comment: 7 pages, 2 figure
Baryon charge transfer and production asymmetry between Lambda^0 and antiLambda^0 in hadron interactions
The predictions were done for asymmetry between production spectra of
Lambda^0 and antiLambda^0 at the energy of LHC experiments. The value of A(s)
should be situated in the band between two curves that are calculated in
Quark-Gluon String Model with two possible values of intercept
alpha_{SJ}(0)=0,5 and 0,9. Both curves describe the asymmetries measured at
lower energies up to RHIC experiments. The data of H1 experiment can be fitted
only with alpha_{SJ}(0)=0,9.Comment: LateX, 7 pages and 2 figures, poster presentation at PANIC'05, Santa
Fe, October 200
Detailing renal hemodynamics and oxygenation in rats by a combined near-infrared spectroscopy and invasive probe approach
We hypothesize that combining quantitative near-infrared spectroscopy (NIRS) with established invasive techniques will enable advanced insights into renal hemodynamics and oxygenation in small animal models. We developed a NIRS technique to monitor absolute values of oxygenated and deoxygenated hemoglobin and of oxygen saturation of hemoglobin within the renal cortex of rats. This NIRS technique was combined with invasive methods to simultaneously record renal tissue oxygen tension and perfusion. The results of test procedures including occlusions of the aorta or the renal vein, hyperoxia, hypoxia, and hypercapnia demonstrated that the combined approach, by providing different but complementary information, enables a more comprehensive characterization of renal hemodynamics and oxygenation
Nonlinear interaction of light with Bose-Einstein condensate: new methods to generate subpoissonian light
We consider -type model of the Bose-Einstein condensate of sodium
atoms interacting with the light. Coefficients of the Kerr-nonlinearity in the
condensate can achieve large and negative values providing the possibility for
effective control of group velocity and dispersion of the probe pulse. We find
a regime when the observation of the "slow" and "fast" light propagating
without absorption becomes achievable due to strong nonlinearity. An effective
two-level quantum model of the system is derived and studied based on the su(2)
polynomial deformation approach. We propose an efficient way for generation of
subpoissonian fields in the Bose-Einstein condensate at time-scales much
shorter than the characteristic decay time in the system. We show that the
quantum properties of the probe pulse can be controlled in BEC by the classical
coupling field.Comment: 13 pages, 6 figures, 1 tabl
Performance of models for predicting one to three year mortality in older adults: a systematic review of externally validated models
Mortality prediction models support identifying older adults with short life expectancy for whom clinical care may need modifications. We systematically reviewed validations of mortality prediction models in older adults with up to three years of follow-up. We included 36 studies reporting 74 validations of 64 unique models. Model applicability was fair but validation risk of bias was mostly high, with 67·7% not reporting calibration. Morbidities were used as predictors by 70·0% of models, most commonly cardiovascular diseases. For 1-year prediction, 31/46 models had acceptable discrimination, but only one had excellent performance. Models with >20 predictors were more likely to have acceptable discrimination (risk ratio (RR) versus <10 predictors 1·68, 95%CI 1·06–2·66), as were models including sex (RR 1·75, 95%CI 1·12–2·73) or predicting risk during comprehensive geriatric assessment (RR 1·86, 95%CI 1·12–3·07). There is a need for derivation and validation of better-performing mortality prediction models in older people.Keywords: Aged; Mortality; Risk; Validation Study; Systematic Review<br/
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