193 research outputs found
Alien Species in the Flora of the Middle Volga Region
The article presents information on the diversity and structure of the alien flora of the Middle Volga region on the border between the steppe and forest-steppe zones of the European botanical and geographical province. In the studied area, we identified 440 alien species of plants (24.6% of the total floristic diversity), including 59 invasive and potentially invasive species, the dispersal of which has already caused environmental consequences or could become a threat in the future. According to the degree of naturalization, alien plant species among the regional flora are represented by 146 ephemerophytes (33.2%), 122 colonophytes (27.7%), 151 epecophytes (34.3%) and 21 agriophytes (4.8%). As verified via the main method of skidding, alien species are distributed almost equally â 228 xenophytes (51.8%) and 212 ergasiophygophytes (48.2%). It was revealed that of the 150 species of alien plants, there are only 84 of the most common European species in the Middle Volga region, most of which do not show high cenotic activity. The obtained results actualize the development of a system of ecological and economic assessment of the consequences of introducing alien plant species into regional flora.
Keywords: alien plants, invasive species, Middle Volga region, regional flor
Protection of Human Rights in the Context of Fight against Gene Doping
This article examines issues related to the protection of human rights in the context of the fight against the use of gene doping. The fact of using gene therapy in relation to a person already includes a significant range of potential ethical problems, including probable health risks, the degree of awareness of the patientâs consent to perform certain manipulations, as well as the long-term consequences for a personâs life, and, which is equally important, for future generations. At the same time, the problems of the use of gene doping in relation to athletes significantly aggravates and complicates the process of building regulatory approaches. The article notes the particular susceptibility of the athlete's right to health care in the context of the problem of gene doping. The paper studies the features of the implementation and protection of the human right to protect health and the right to privacy, including legislation aspect of biomedicine and bioethics, as well as taking into account the difficulties associated with the identification of the use of gene doping. Conclusions regarding possible areas for improving legal regulation in this area, among which, strengthening or detailing the legal regulation of the provision of high-tech medical care, properly informing athletes, coaches and other sports professionals about the possible risks of applying genetic engineering methods to humans, proper regulation of testing procedures, toughening criminal liability and expansion of the subject matter of such crimes are formulated
Polygonal Structures in the Gaseous Disk: Numerical Simulations
The results of numerical simulations of a gaseous disk in the potential of a
stellar spiral density wave are presented. The conditions under which
straightened spiral arm segments (rows) form in the gas component are studied.
These features of the spiral structure were identified in a series of works by
A.D. Chernin with coauthors. Gas-dynamic simulations have been performed for a
wide range of model parameters: the pitch angle of the spiral pattern, the
amplitude of the stellar spiral density wave, the disk rotation speed, and the
temperature of the gas component. The results of 2D- and 3D-disk simulations
are compared. The rows in the numerical simulations are shown to be an
essentially nonstationary phenomenon. A statistical analysis of the
distribution of geometric parameters for spiral patterns with rows in the
observed galaxies and the constructed hydrodynamic models shows good agreement.
In particular, the numerical simulations and observations of galaxies give
for the average angles between straight segments.Comment: 22 pages, 10 figure
Theory of Fulde-Ferrell-Larkin-Ovchinnikov state of superconductors with and without inversion symmetry: Hubbard model approach
We study Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state of superconductors
with and without inversion symmetry based on the Hubbard model on the square
lattice near half-filling, using the random phase approximation. We show that
center of mass momentum tends to be parallel to - or y-axis in the
presence of inversion symmetry, while vector is likely to be perpendicular
to the magnetic field in the absence of inversion symmetry. We also clarify
that -wave pairing is favored and the hetero spin triplet -wave state
is present in the FFLO state unlike state in the superconductors only with the
Rashba type spin-orbit coupling (RSOC) originating from the broken inversion
symmetry. The triplet -wave state is enhanced by magnetic field and the
RSOC. This stems from the reduction of the spin susceptibilities by the
magnetic field and the RSOC.Comment: 9 pages, 15 figures, 1 tabl
Determining global parameters of the oscillations of solar-like stars
Helioseismology has enabled us to better understand the solar interior, while
also allowing us to better constrain solar models. But now is a tremendous
epoch for asteroseismology as space missions dedicated to studying stellar
oscillations have been launched within the last years (MOST and CoRoT). CoRoT
has already proved valuable results for many types of stars, while Kepler,
which was launched in March 2009, will provide us with a huge number of seismic
data very soon. This is an opportunity to better constrain stellar models and
to finally understand stellar structure and evolution. The goal of this
research work is to estimate the global parameters of any solar-like
oscillating target in an automatic manner. We want to determine the global
parameters of the acoustic modes (large separation, range of excited pressure
modes, maximum amplitude, and its corresponding frequency), retrieve the
surface rotation period of the star and use these results to estimate the
global parameters of the star (radius and mass).To prepare the analysis of
hundreds of solar-like oscillating stars, we have developed a robust and
automatic pipeline. The pipeline consists of data analysis techniques, such as
Fast Fourier Transform, wavelets, autocorrelation, as well as the application
of minimisation algorithms for stellar-modelling. We apply our pipeline to some
simulated lightcurves from the asteroFLAG team and the Aarhus-asteroFLAG
simulator, and obtain results that are consistent with the input data to the
simulations. Our strategy gives correct results for stars with magnitudes below
11 with only a few 10% of bad determinations among the reliable results. We
then apply the pipeline to the Sun and three CoRoT targets.In particular we
determine the parameters of the Sun, HD49933, HD181906, and HD181420.Comment: 15 pages, 17 figures, accepted for publication in A&
2D Spectroscopy of Candidate Polar-Ring Galaxies: I. The Pair of Galaxies UGC 5600/09
Observations of the pair of galaxies VV 330 with the SCORPIO multimode
instrument on the 6-m Special Astrophysical Observatory telescope are
presented. Large-scale velocity fields of the ionized gas in H-alfa and
brightness distributions in continuum and H-alfa have been constructed for both
galaxies with the help of a scanning Fabry Perot interferometer. Long-slit
spectroscopy is used to study the stellar kinematics. Analysis of the data
obtained has revealed a complex structure in each of the pair components. Three
kinematic subsystems have been identified in UGC 5600: a stellar disk, an inner
gas ring turned with respect to the disk through ~80degrees, and an outer gas
disk. The stellar and outer gas disks are noncoplanar. Possible scenarios for
the formation of the observed multicomponent kinematic galactic structure are
considered, including the case where the large-scale velocity field of the gas
is represented by the kinematic model of a disk with a warp. The velocity field
in the second galaxy of the pair, UGC 5609, is more regular. A joint analysis
of the data on the photometric structure and the velocity field has shown that
this is probably a late-type spiral galaxy whose shape is distorted by the
gravitational interaction, possibly, with UGC 5600.Comment: 18 pages, 6 figure
Recent Developments in Helioseismic Analysis Methods and Solar Data Assimilation
MR and AS have received funding from the European Research Council under the European Unionâs Seventh Framework Program (FP/2007-2013)/ERC Grant Agreement no. 307117
Quenched bond randomness in marginal and non-marginal Ising spin models in 2D
We investigate and contrast, via entropic sampling based on the Wang-Landau
algorithm, the effects of quenched bond randomness on the critical behavior of
two Ising spin models in 2D. The random bond version of the
superantiferromagnetic (SAF) square model with nearest- and
next-nearest-neighbor competing interactions and the corresponding version of
the simple Ising model are studied and their general universality aspects are
inspected by a detailed finite-size scaling (FSS) analysis. We find that, the
random bond SAF model obeys weak universality, hyperscaling, and exhibits a
strong saturating behavior of the specific heat due to the competing nature of
interactions. On the other hand, for the random Ising model we encounter some
difficulties for a definite discrimination between the two well-known scenarios
of the logarithmic corrections versus the weak universality. Yet, a careful FSS
analysis of our data favors the field-theoretically predicted logarithmic
corrections.Comment: 19 pages, 5 figures, final versio
Propagating Star Formation in the Collisional Ring Galaxy Arp 10
Propagating star formation in a collisional ring galaxy Arp10 is investigated
by a complex approach, which includes the broad- and narrow-band photometry,
long- slit spectroscopy, and scanning Fabry-Perot spectroscopy. The ionized gas
velocity field obtained with best spatial resolution to date indicates a non-
isotropic expansion of the outer ring with a maximum velocity 110km/s. Strong
vertical and non-circular motions are also seen in the vicinity of the inner
ring. Our kinematic data suggest that Arp10 has a small inclination i=22\degr
and high total (luminous plus dark matter) mass of about
within a 50 kpc radius.The abundance of oxygen 12 + log(O/H) in both star-
forming rings is about 8.6.The analysis of spectral indices provides an
estimate on the propagation velocities of both rings and metallicity of the
pre-collision stellar population.A small "knot" near the nucleus of Arp10,which
was previously suspected as a possible candidate for collision, is now
unambiguously identified as the "intruder" of at least 1/4 of the total mass of
Arp~10.We use a simplified two-dimensional hydrodynamic modeling of galaxy
collisions to test a collisional origin of Arp10. We confirm that the sizes of
the inner and outer rings, maximum expansion velocity of the outer ring, and
radial profile of the gas circular velocity can be reproduced by a near-central
collision with the intruder galaxy, which occurred approximately 85Myr ago. We
acknowledge that an apparent crescent- shaped distribution of H
emission in the outer ring is caused by a star formation threshold in the gas
disk of Arp10.Comment: 17 pages, 17 figures, accepted by Ap
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