219 research outputs found
Investigation of the New Local Group Galaxy VV 124
We present the results of our stellar photometry and spectroscopy for the new
Local Group galaxy VV 124 (UGC 4879) obtained with the 6-m BTA telescope. The
presence of a few bright supergiants in the galaxy indicates that the current
star formation process is weak. The apparent distribution of stars with
different ages in VV 124 does not differ from the analogous distributions of
stars in irregular galaxies, but the ratio of the numbers of young and old
stars indicates that VV 124 belongs to the rare Irr/Sph type of galaxies. The
old stars (red giants) form the most extended structure, a thick disk with an
exponential decrease in the star number density to the edge. Definitely, the
young population unresolvable in images makes a great contribution to the
background emission from the central galactic regions. The presence of young
stars is also confirmed by the [O III] emission line visible in the spectra
that belongs to extensive diffuse galactic regions. The mean radial velocity of
several components (two bright supergiants, the unresolvable stellar
population, and the diffuse gas) is v_h = -70+/-15 km/s and the velocity with
which VV 124 falls into the Local Group is v_LG = -12+/-15 km/s. We confirm the
distance to the galaxy D = 1.1+/-0.1 Mpc and the metallicity of red giants
([Fe/H] = -1.37) found by Kopylov et al. (2008).VV 124 is located on the
periphery of the Local Group approximately at the same distance from M 31 and
our Galaxy and is isolated from other galaxies. The galaxy LeoA nearest to it
is 0.5 Mpc away.Comment: 10 pages, 8 figures. Accepted for publication in Astronomy Letters
(2010, Vol. 36, No. 5, pp. 309-318
Some aspects of examination of children with combined spine and pelvis pathology living in an industrial city
The aim of the study was to analyze the peculiarities of combined spinal and pelvic pathology in children living on the industrial area of the Irkutsk Region. To perform the analysis we carried out the clinical-roentgenological research, and when making orthopedic examination we took into consideration ecological factors and used the chart of multivariative analysis. It was found that in the structure of combined pathology, pelvis asymmetry ranks first, scoliosis ranks second, Legg - Calve - Perthes disease ranks third. According to the assessment of age structure of combined pathology we can conclude that at the equal manifestations of scoliosis, Spina bifida, retrospondylolisthesis, pelvis asymmetry, children of 11-15 y.o. more often have Legg - Calve - Perthes disease, children of 16-21 y.o. - coxarthrosis. In its turn relative share of Legg - Calve - Perthes disease cases in children living within a radius of 5 km from the industrial center is the largest (21 из 28 cases). It's important to mention that Legg - Calve - Perthes disease was registered in all examined boys and only in 35.5 % of girls. I and II degrees of manifestation of clinicoroentgenologic disorders of combined spine and pelvis pathology prevail (77 and 43 cases correspondingly) over the disorders of the III degree (15 cases)
Correlation search for coherent pion emission in heavy ion collisions
The methods allowing to extract the coherent component of pion emission
conditioned by the formation of a quasi-classical pion source in heavy ion
collisions are suggested. They exploit a nontrivial modification of the quantum
statistical and final state interaction effects on the correlation functions of
like and unlike pions in the presence of the coherent radiation. The extraction
of the coherent pion spectrum from pi+pi-, pi+pi+ and pi-pi- correlation
functions and single--pion spectra is discussed in detail for large expanding
systems produced in ultra-relativistic heavy ion collisions.Comment: 21 pages, 3 eps figures, ReVTeX, corrected submission abstract.
Version published in PRC 65 (2002) 064904. Added is a detailed explanation of
the differences between pure coherent states and charge constrained coherent
states in the case of a simple example model. The expressions for
two-particle spectra taking into account both the final state interaction and
the coherent component of pion emission are derived in a more general and
transparent wa
Panenteric capsule endoscopy identifies proximal small bowel disease guiding upstaging and treatment intensification in Crohn’s disease: A European multicentre observational cohort study
Background: Endoscopically defined mucosal healing in Crohn\u2019s disease is associated with improved outcomes. Panenteric capsule endoscopy enables a single non-invasive assessment of small and large bowel mucosal inflammation. Aims and methods: This multicentre observational study of patients with suspected and established Crohn\u2019s disease examined the feasibility, safety and impact on patient outcomes of panenteric capsule endoscopy in routine clinical practice. The potential role in assessment of disease severity and extent by a comparison with existing clinical and biochemical markers is examined. Results: Panenteric capsule endoscopy was performed on 93 patients (71 with established and 22 with suspected Crohn\u2019s disease). A complete examination occurred in 85% (79/93). Two cases (2.8%) of capsule retention occurred in patients with established Crohn\u2019s disease. Panenteric capsule resulted in management change in 38.7% (36/93) patients, including 64.6% (32/48) of those with an established diagnosis whose disease was active, and all three patients with newly diagnosed Crohn\u2019s disease. Montreal classification was upstaged in 33.8% of patients with established Crohn\u2019s disease and mucosal healing was demonstrated in 15.5%. Proximal small bowel disease upstaged disease in 12.7% and predicted escalation of therapy (odds ratio 40.3, 95% confidence interval 3.6\u2013450.2). Raised C-reactive protein and faecal calprotectin were poorly sensitive in detecting active disease (0.48 and 0.59 respectively). Conclusions: Panenteric capsule endoscopy was feasible in routine practice and the ability to detect proximal small bowel disease may allow better estimation of prognosis and guide treatment intensification. Panenteric capsule endoscopy may be a suitable non-invasive endoscopic investigation in determining disease activity and supporting management decisions
Multi-boson effects and the normalization of the two-pion correlation function
The two-pion correlation function can be defined as a ratio of either the
measured momentum distributions or the normalized momentum space probabilities.
We show that the first alternative avoids certain ambiguities since then the
normalization of the two-pion correlator contains important information on the
multiplicity distribution of the event ensemble which is lost in the second
alternative. We illustrate this explicitly for specific classes of event
ensembles.Comment: 6 pages, three figures,submit to PR
The Structure of Clusters with Bimodal Distributions of Galaxy Radial Velocities. I. A1035
The structure of the A1035 cluster of galaxies (10h32m +40d13', cz ~ 22000
km/s), which exhibits a bimodal distribution of galaxy radial velocities
(\Delta V\approx 3000 km/s), is analyzed using three methods of determining the
relative distances to clusters from early-type galaxies: the Kormendy relation
corrected for the dependence of residuals on galaxy magnitude, the photometric
plane, and the fundamental plane. We use the data obtained with the 1-m
telescope of the Special Astrophysical Observatory of the Russian Academy of
Sciences and SDSS (DR5) data to show that A1035 consists of two gravitationally
unbound independent clusters. These clusters with the velocity dispersions of
566 km/s and 610 km/s and masses within R_200 equal to 2.7 10^14 and 3.5 10^14
M_sun, respectively, obey the Hubble law.Comment: 13 pages, 3 tables, 6 figure
Nomenclature and semantic description of vascular lesions in small bowel capsule endoscopy: an international Delphi consensus statement
Background and study aims \u2002Nomenclature and descriptions of small bowel (SB) vascular lesions in capsule endoscopy (CE) are scarce in the medical literature. They are mostly based on the reader's opinion and thus differ between experts, with a potential negative impact on clinical care, teaching and research regarding SBCE. Our aim was to better define a nomenclature and to give a description of the most frequent vascular lesions in SBCE. Methods \u2002A panel of 18 European expert SBCE readers was formed during the UEGW 2016 meeting. Three experts constructed an Internet-based four-round Delphi consensus, but did not participate in the voting process. They built questionnaires that included various still frames of vascular lesions obtained with a third-generation SBCE system. The 15 remaining participants were asked to rate different proposals and description of the most common SB vascular lesions. A 6-point rating scale (varying from 'strongly disagree' to 'strongly agree') was used successive rounds. The consensus was reached when at least 80\u200a% voting members scored the statement within the 'agree' or 'strongly agree'. Results \u2002Consensual terms and descriptions were reached for angiectasia/angiodysplasia, erythematous patch, red spot/dot, and phlebectasia. A consensual description was reached for more subtle vascular lesions tentatively named "diminutive angiectasia" but no consensus was reached for this term. Conclusion \u2002An international group has reached a consensus on the nomenclature and descriptions of the most frequent and relevant SB vascular lesions in CE. These terms and descriptions are useful in daily practice, for teaching and for medical research purposes
Microscopic study of freeze-out in relativistic heavy ion collisions at SPS energies
The freeze-out conditions in the light (S+S) and heavy (Pb+Pb) colliding
systems of heavy nuclei at 160 AGeV/ are analyzed within the microscopic
Quark Gluon String Model (QGSM). We found that even for the most heavy systems
particle emission takes place from the whole space-time domain available for
the system evolution, but not from the thin ''freeze-out hypersurface", adopted
in fluid dynamical models. Pions are continuously emitted from the whole volume
of the reaction and reflect the main trends of the system evolution. Nucleons
in Pb+Pb collisions initially come from the surface region. For both systems
there is a separation of the elastic and inelastic freeze-out. The mesons with
large transverse momenta, , are predominantly produced at the early stages
of the reaction. The low -component is populated by mesons coming mainly
from the decay of resonances. This explains naturally the decreasing source
sizes with increasing , observed in HBT interferometry. Comparison with
S+S and Au+Au systems at 11.6 AGeV/ is also presented.Comment: REVTEX, 26 pages incl. 9 figures and 2 tables, to be published in the
Physical Review
Model-independent source imaging using two-pion correlations in 2 to 8A GeV Au + Au collisions
We report a particle source imaging analysis based on two-pion correlations
in high multiplicity Au + Au collisions at beam energies between 2 and 8A GeV.
We apply the imaging technique introduced by Brown and Danielewicz, which
allows a model-independent extraction of source functions with useful accuracy
out to relative pion separations of about 20 fm. The extracted source functions
have Gaussian shapes. Values of source functions at zero separation are almost
constant across the energy range under study. Imaging results are found to be
consistent with conventional source parameters obtained from a multidimensional
HBT analysis.Comment: 4 pages, 3 figure
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