On the identification of the source of emission on the plane

We consider the problem of identification of the position and the moment of the beginning of a radioactive source emission on the plane. The acts of emission constitute inhomogeneous Poisson processes and are registered by K detectors on the plane. We suppose that the moments of arriving of the signals at the detectors are measured with some small errors. Then, using these estimate, we construct the estimators of the position of source and the moment of the beginning of emission. We study the asymptotic properties of these estimators for large signals and prove their consistency

Globular clusters as indicators of Galactic evolution

We have studied the system of globular clusters (GCs) that formed in other galaxies and eventually accreted onto the Milky Way. Thus, the samples of GCs belonging to different tidal streams, obtained on the basis of the latest data from the Gaia observatory, were taken from the literature. We measured the anisotropy of the distribution of these GCs using the gyration tensor and found that the distribution of GCs in the streams is isotropic. Nevertheless, it can be seen that some of the accreted GCs included into existing samples actually belong to the disk of the Galaxy. To clarify the origin of GCs, we investigated the ``age--metallicity'' relation. This dependence demonstrates bimodality and its two different branches clearly show the difference between the clusters formed in the streams and in the disk of the Galaxy. Furthermore, we have studied the influence of the large--scale environment of the Galaxy (i.e., the Local Supercluster) on the distribution of satellite galaxies and Galactic GCs. The satellite galaxies of the Milky Way are known to form an anisotropic planar structure, so we included them in our analysis too. An inspection has shown that the plane of the satellite galaxies is perpendicular both to the disk of the Galaxy and the supergalactic plane. For GCs more distant than 100~Kpc, a similar picture is observed.Comment: 15 pages, 3 figure

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

Nonlinear interaction of light with Bose-Einstein condensate: new methods to generate subpoissonian light

We consider $\Lambda$-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

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

Pion Content of the Nucleon as seen in the NA51 Drell-Yan experiment

In a recent CERN Drell-Yan experiment the NA51 group found a strong asymmetry of $\bar u$ and $\bar d$ densities in the proton at $x\simeq0.18$. We interpret this result as a decisive confirmation of the pion-induced sea in the nucleon.Comment: 10 pages + 3 figures, Preprint KFA-IKP(TH)-1994-14 .tex file. After \enddocument a uu-encodeded Postscript file comprising the figures is appende

Lambda-Baryon Production in pi(+-)n Interactions

The process of Lambda-baryon production in pi-p collisions is considered. The contribution of the string-junction mechanism to the strange baryon production in meson-baryon scattering is anlysed. The results of numerical calculations in the framework of the Quark-Gluon String model are in reasonable agreement with the data.Comment: 10 pages and 5 figue

Выявление поражения коронарных артерий и тактика хирургического лечения у пациентов с хронической ишемией нижних конечностей

Introduction. Ischemic heart disease is undoubtedly the main factor that significantly aggravates the condition of patients with chronic lower limb ischemia in the perioperative period.Aim. To establish the expediency of mandatory performance of selective polypositional coronary angiography in patients with chronic ischemia of the lower extremities to determine the stages of surgical intervention and prevent cardiac complications.Materials and methods. The study included 285 patients, treated to the Department of arterial pathology surgery of the Bakulev National Medical Research Center of Cardiovascular Surgery with a diagnosis of chronic lower limb ischemia. The patients were divided into 2 groups. The main group included 139 patients admitted in 2016. The control group – 146 patients admitted in 1989. In the main group, all patients underwent coronary angiography. In the control group, coronary angiography was performed only in patients with a clinical picture of coronary artery disease or in asymptomatic patients after positive stress tests.Results and discussion. After analysis of coronary angiograms in patients of the main group, out of 139 patients included in the study, 124 (89.2%) had a lesion of at least 1 coronary artery &gt;50%; and in 101 (72.7%) patients, at least 1 coronary artery was affected &gt;70%. In the main group, cardiac complications were noted in 6 (4.32%) patients, while in the control group they were detected in 21 (14.4%) cases. These complications appeared due to the underestimation of the state of the coronary bed, based only on the results of stress tests.Conclusions. Selective polypositional coronary angiography is the main method for detecting asymptomatic significant coronary artery disease in patients with CLCI, which improves the immediate results of surgical treatment by reducing the incidence of cardiac complications.Введение. Ишемическая болезнь сердца (ИБС), несомненно, является главным фактором, существенно утяжеляющим состояние больных с хронической ишемией нижних конечностей (ХИНК) в периоперационном периоде.Цель исследования. Установить целесообразность обязательного выполнения селективной полипозиционной коронарографии пациентам с ХИНК для определения этапности оперативного вмешательства и предотвращения кардиальных осложнений.Материалы и методы. В исследование вошли 285 больных, проходивших лечение в отделении хирургии артериальной патологии НМИЦ сердечно-сосудистой хирургии имени А.Н. Бакулева с диагнозом ХИНК. Пациенты были разделены на 2 группы: в основную группу вошли 139 пациентов, поступивших в 2016 г., в контрольную – 146 пациентов, поступивших в 1989 г. В основной группе всем пациентам выполнялась коронарография. В контрольной группе коронарография выполнялась лишь больным с клинической картиной ИБС или асимптомным пациентам после положительных стресс-тестов.Результаты и обсуждение. После анализа коронарограмм у пациентов основной группы из 139 пациентов вошедших в исследование у 124 (89,2%) было выявлено поражение как минимум 1 коронарной артерии (&gt;50%), у 101 (72,7%) больного было выявлено поражение хотя бы 1 коронарной артерии (&gt;70%). В основной группе кардиальные осложнения были отмечены у 6 (4,32%) больных, тогда как в контрольной группе они были выявлены у 21 (14,4%) чел. Данного рода осложнения явились следствием недооцененности состояния коронарного русла, основанного лишь на результатах стресс-тестов.Заключение. Селективная полипозиционная коронарография является основным методом выявления асимптомной значимой ИБС у пациентов с ХИНК, что позволяет улучшить непосредственные результаты хирургического лечения за счет снижения частоты кардиальных осложнений

SDiff(2) Toda equation -- hierarchy, τ\tau function, and symmetries

A continuum limit of the Toda lattice field theory, called the SDiff(2) Toda equation, is shown to have a Lax formalism and an infinite hierarchy of higher flows. The Lax formalism is very similar to the case of the self-dual vacuum Einstein equation and its hyper-K\"ahler version, however now based upon a symplectic structure and the group SDiff(2) of area preserving diffeomorphisms on a cylinder $S^1 \times \R$. An analogue of the Toda lattice tau function is introduced. The existence of hidden SDiff(2) symmetries are derived from a Riemann-Hilbert problem in the SDiff(2) group. Symmetries of the tau function turn out to have commutator anomalies, hence give a representation of a central extension of the SDiff(2) algebra.Comment: 16 pages (``vanilla.sty" is attatched to the end of this file after ``\bye" command