137 research outputs found
Diagnostics and correction of vestibular, autonomic and vascular dysfunctions on the background of degenerative changes in the cervical spin
Studies in 82 patients were aimed at optimizing the diagnosis and treatment of vestibular dysfunctions with vegetative-vascular disorders during degenerative changes in the cervical spine.The main symptoms of vestibulopathy were dizziness as well as their provoking and related causes. Obtained objective state data of the vestibular analyzer using the integrative index of ataxia, the state of autonomic characteristics, data of the psychoemotional and cognitive sphere. The author's method of treating such conditions using a complex of vegetotropic, vascular, nootropic drugs, as well as intranasal electrophoresis, was used. Positive results were obtained for this type of therapy for vestibulopathy and autonomic vascular disorders
The Universality of Initial Conditions for Globular Cluster Formation
We investigate a simple model for globular cluster (GC) formation. We
simulate the violent relaxation of initially homogeneous isothermal stellar
spheres and show that it leads to the formation of clusters with radial density
profiles that match the observed profiles of GCs. The best match is achieved
for dynamically unevolved clusters. In this model, all the observed
correlations between global GC parameters are accurately reproduced if one
assumes that all the clusters initially had the same value of the stellar
density and the velocity dispersion. This suggests that the gas which formed
GCs had the same values of density and temperature throughout the universe.Comment: 12 pages, 4 figures, 1 table. Accepted for publication in ApJ Letter
Possibility of therapy of acute ischemic stroke by polyphenols of flavonoid group
Objective - to study neuroprotective effect of Quercetin in ischemia-reperfusion injury in acute ischemic stroke.
Materials and methods. The study included 98 patients with acute ischemic stroke. All patients: main and control group, received standard treatment in accordance with the clinical protocol order Ministry of Health of Ukraine from 03.08.2012, â„– 602. Patients of the main group (n=68) on the back of the base further treatment was administered quercetin (Corvitin lyophilisate injection solution) course of 10 days according to the scheme: 500 mg of the drug diluted in 100 ml of 0.9% of the physiological solution intravenously twice a day for the first five days and once a day for the next five days. Patients in the control group (n=30) - quercetin is not appointed. Assessment by GCS, NIHSS, Barthel served in the 1st, 3rd, 5th, 10th day of the disease.
Results. Simultaneously with the standard treatment, intravenous administration of quercetin, positively influenced the regression of focal neurological symptoms on the NIHSS and Barthel scales in patients with acute ischemic stroke, increased the proportion of patients in the consciousness or with its minor impairments in the GCS, ie contributed to an earlier “awakening” in acute ischemic stroke.
Conclusions. Neuroprotective effect of quercetin (Corvitin lyophilisate injection solution) can be explained by its polytropic, antioxidant, anti-inflammatory, membrane-stabilizing effect in ischemia-reperfusion
Constraining global properties of the Draco dwarf spheroidal galaxy
By fitting a flexible stellar anisotropy model to the observed surface
brightness and line-of-sight velocity dispersion profiles of Draco we derive a
sequence of cosmologically plausible two-component (stars + dark matter) models
for this galaxy. The models are consistent with all the available observations
and can have either cuspy Navarro-Frenk-White or flat-cored dark matter density
profiles. The dark matter halos either formed relatively recently (at z~2...7)
and are massive (up to ~5x10^9 M_Sun), or formed before the end of the
reionization of the universe (z~7...11) and are less massive (down to ~7x10^7
M_Sun). Our results thus support either of the two popular solutions of the
"missing satellites" problem of Lambda cold dark matter cosmology - that dwarf
spheroidals are either very massive, or very old. We carry out high-resolution
simulations of the tidal evolution of our two-component Draco models in the
potential of the Milky Way. The results of our simulations suggest that the
observable properties of Draco have not been appreciably affected by the
Galactic tides after 10 Gyr of evolution. We rule out Draco being a "tidal
dwarf" - a tidally disrupted dwarf galaxy. Almost radial Draco orbits (with the
pericentric distance <15 kpc) are also ruled out by our analysis. The case of a
harmonic dark matter core can be consistent with observations only for a very
limited choice of Draco orbits (with the apocentric-to-pericentric distances
ratio of <2.5).Comment: 18 pages, 14 figures; accepted by Ap
Globular Clusters with Dark Matter Halos. II. Evolution in Tidal Field
In this second paper in our series, we continue to test primordial scenarios
of globular cluster formation which predict that globular clusters formed in
the early universe in the potential of dark matter minihalos. In this paper we
use high-resolution N-body simulations to model tidal stripping experienced by
primordial dark-matter dominated globular clusters in the static gravitational
potential of the host dwarf galaxy. We test both cuspy Navarro-Frenk-White
(NFW) and flat-core Burkert models of dark matter halos. Our primordial
globular cluster with an NFW dark matter halo survives severe tidal stripping,
and after 10 orbits is still dominated by dark matter in its outskirts. Our
cluster with Burkert dark matter halo loses almost all its dark matter to tidal
stripping, and starts losing stars at the end of our simulations. The results
of this paper reinforce our conclusion in Paper I that current observations of
globular clusters are consistent with the primordial picture of globular
cluster formation.Comment: 12 pages, 9 figures. Astrophysical Journal, in pres
On the origin of the neutral hydrogen supershells: the ionized progenitors and the limitations of the multiple supernovae hypothesis
Here we address the question whether the ionized shells associated with giant
HII regions can be progenitors of the larger HI shell-like objects found in the
Milky Way and other spiral and dwarf irregular galaxies. We use for our
analysis a sample of 12 HII shells presented recently by Rela\~no et al. (2005,
2007). We calculate the evolutionary tracks that these shells would have if
their expansion is driven by multiple supernovae explosions from the parental
stellar clusters. We find, contrary to Rela\~no et al. (2007), that the
evolutionary tracks of their sample HII shells are inconsistent with the
observed parameters of the largest and most massive neutral hydrogen
supershells. We conclude that HII shells found inside giant HII regions may
represent the progenitors of small or intermediate HI shells, however they
cannot evolve into the largest HI objects unless, aside from the multiple
supernovae explosions, an additional energy source contributes to their
expansion.Comment: Accepted for publication in ApJ, tentatively scheduled for the ApJ
July 1, 2008, v681n1 issue. 19 pages, 4 figure
Automatic Detection of Expanding HI Shells Using Artificial Neural Networks
The identification of expanding HI shells is difficult because of their
variable morphological characteristics. The detection of HI bubbles on a global
scale therefore never has been attempted. In this paper, an automatic detector
for expanding HI shells is presented. The detection is based on the more stable
dynamical characteristics of expanding shells and is performed in two stages.
The first one is the recognition of the dynamical signature of an expanding
bubble in the velocity spectra, based on the classification of an artificial
neural network. The pixels associated with these recognized spectra are
identified on each velocity channel. The second stage consists in looking for
concentrations of those pixels that were firstly pointed out, and to decide if
they are potential detections by morphological and 21-cm emission variation
considerations. Two test bubbles are correctly detected and a potentially new
case of shell that is visually very convincing is discovered. About 0.6% of the
surveyed pixels are identified as part of a bubble. These may be false
detections, but still constitute regions of space with high probability of
finding an expanding shell. The subsequent search field is thus significantly
reduced. We intend to conduct in the near future a large scale HI shells
detection over the Perseus Arm using our detector.Comment: 39 pages, 11 figures, accepted by PAS
To the problems of modeling the brain ischemia in small animals
In the review article the problems of modeling cerebral ischemia in small mammals are consecrated. The advantages of experimental studies that are based on the similarity of the blood circulation of the brain in humans and animals are indicated. Classification of experimental models for the study of acute and chronic disorders of cerebral circulation, mechanisms of their development and preclinical approbation of new drugs is given. The authors indicate that all experimental models of brain ischemia can be divided into two groups: to study risk factors and pathophysiological studies of brain ischemia. And in the second case, the models of focal and global ischemia are described. In conclusion, the authors point out the difficulties and shortcomings of certain methods of ischemia reproduction, which await researchers to solve the above problems
HIIphot: Automated Photometry of HII Regions Applied to M51
We have developed a robust, automated method, hereafter designated HIIphot,
which enables accurate photometric characterization of HII regions while
permitting genuine adaptivity to irregular source morphology. HIIphot utilizes
object-recognition techniques to make a first guess at the shapes of all
sources then allows for departure from such idealized ``seeds'' through an
iterative growing procedure. Photometric corrections for spatially coincident
diffuse emission are derived from a low-order surface fit to the background
after exclusion of all detected sources. We present results for the
well-studied, nearby spiral M51 in which 1229 HII regions are detected above
the 5-sigma level. A simple, weighted power-law fit to the measured H-alpha
luminosity function (HII LF) above log L_H-alpha = 37.6 gives alpha =
-1.75+/-0.06, despite a conspicuous break in the HII LF observed near L_H-alpha
= 10^38.9. Our best- fit slope is marginally steeper than measured by Rand
(1992), perhaps reflecting our increased sensitivity at low luminosities and to
notably diffuse objects. HII regions located in interarm gaps are
preferentially less luminous than counterparts which constitute M51's
grand-design spiral arms and are best fit with a power-law slope of alpha =
-1.96+/-0.15. We assign arm/interarm status for HII regions based upon the
varying surface brightness of diffuse emission as a function of position
throughout the image. Using our measurement of the integrated flux contributed
by resolved HII regions in M51, we estimate the diffuse fraction to be
approximately 0.45 -- in agreement with the determination of Greenawalt et al.
(1998). Automated processing of degraded datasets is undertaken to gauge
systematic effects associated with limiting spatial resolution and sensitivity.Comment: 41 pages, 14 figures, Postscript version with high-resolution figures
at ftp://ftp.aoc.nrao.edu/staff/dthilker/preprint
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