1,602 research outputs found
On a low energy bound in a class of chiral field theories with solitons
A low energy bound in a class of chiral solitonic field theories related the
infrared physics of the SU(N) Yang-Mills theory is established.Comment: Plain Latex, 8 pages, no figure
The value of extended amygdala structures in emotive effects of narcogenic with diverse chemical structure
To clarify the value of the extended amygdala structures (bed nucleus, central nucleus of the amygdala and nucleus accumbens shell) in the mechanisms of unconditioned and conditioned reinforcement activated by various narcogenic, this paper carried out a neuropharmacological analysis of these effects, using blockade of dopamine receptors, GABA, opioids and CRF receptors within these brain structures, as well as an analysis of behavioral responses by self-stimulation (unconditioned reinforcement) and conditioned place preference (CPP) (conditioned reinforcement
Mutual maintenance of di- and triploid Pelophylax esculentus hybrids in R-E systems: results fro
Background: Interspecies animal hybrids can employ clonal or hemiclonal reproduction modes where one or all
parental genomes are transmitted to the progeny without recombination. Nevertheless, some interspecies
hybrids retain strong connection with the parental species needed for successful reproduction. Appearance of
polyploid hybrid animals may play an important role in the substitution of parental species and in the
speciation process.
Results: To establish the mechanisms that enable parental species, diploid and polyploid hybrids coexist we
have performed artificial crossing experiments of water frogs of Pelophylax esculentus complex. We identified
tadpole karyotypes and oocyte genome composition in all females involved in the crossings. The majority of
diploid and triploid hybrid frogs produced oocytes with 13 bivalents leading to haploid gametes with the
same genome as parental species hybrids usually coexist with. After fertilization of such gametes only diploid
animals appeared. Oocytes with 26 bivalents produced by some diploid hybrid frogs lead to diploid gametes,
which give rise to triploid hybrids after fertilization. In gonads of all diploid and triploid hybrid tadpoles we
found DAPI-positive micronuclei (nucleus-like bodies) involved in selective genome elimination. Hybrid male
and female individuals produced tadpoles with variable karyotype and ploidy even in one crossing owing to
gametes with various genome composition.
Conclusions: We propose a model of diploid and triploid hybrid frog reproduction in R-E population systems.
Triploid Pelophylax esculentus hybrids can transmit genome of parental species they coexist with by producing
haploid gametes with the same genome composition. Triploid hybrids cannot produce triploid individuals
after crossings with each other and depend on diploid hybrid females producing diploid eggs. In contrast to
other population systems, the majority of diploid and triploid hybrid females unexpectedly produced gametes
with the same genome as parental species hybrids coexist with
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Physical interpretation of the correlation between multi-angle spectral data and canopy height
Recent empirical studies have shown that multi-angle spectral data can be useful for predicting canopy height, but the physical reason for this correlation was not understood. We follow the concept of canopy spectral invariants, specifically escape probability, to gain insight into the observed correlation. Airborne Multi-Angle Imaging Spectrometer (AirMISR) and airborne Laser Vegetation Imaging Sensor (LVIS) data acquired during a NASA Terrestrial Ecology Program aircraft campaign underlie our analysis. Two multivariate linear regression models were developed to estimate LVIS height measures from 28 AirMISR multi-angle spectral reflectances and from the spectrally invariant escape probability at 7 AirMISR view angles. Both models achieved nearly the same accuracy, suggesting that canopy spectral invariant theory can explain the observed correlation. We hypothesize that the escape probability is sensitive to the aspect ratio (crown diameter to crown height). The multi-angle spectral data alone therefore may not provide enough information to retrieve canopy height globally
Weyl group, CP and the kink-like field configurations in the effective SU(3) gauge theory
Effective Lagrangian for pure Yang-Mills gauge fields invariant under the
standard space-time and local gauge SU(3) transformations is considered. It is
demonstrated that a set of twelve degenerated minima exists as soon as a
nonzero gluon condensate is postulated. The minima are connected to each other
by the parity transformations and Weyl group transformations associated with
the color su(3) algebra. The presence of degenerated discrete minima in the
effective potential leads to the solutions of the effective Euclidean equations
of motion in the form of the kink-like gauge field configurations interpolating
between different minima. Spectrum of charged scalar field in the kink
background is discussed.Comment: 10 pages, 1 figure, added references for sections 1 and
Lagrangian and Hamiltonian Formalism on a Quantum Plane
We examine the problem of defining Lagrangian and Hamiltonian mechanics for a
particle moving on a quantum plane . For Lagrangian mechanics, we
first define a tangent quantum plane spanned by noncommuting
particle coordinates and velocities. Using techniques similar to those of Wess
and Zumino, we construct two different differential calculi on .
These two differential calculi can in principle give rise to two different
particle dynamics, starting from a single Lagrangian. For Hamiltonian
mechanics, we define a phase space spanned by noncommuting
particle coordinates and momenta. The commutation relations for the momenta can
be determined only after knowing their functional dependence on coordinates and
velocities.
Thus these commutation relations, as well as the differential calculus on
, depend on the initial choice of Lagrangian. We obtain the
deformed Hamilton's equations of motion and the deformed Poisson brackets, and
their definitions also depend on our initial choice of Lagrangian. We
illustrate these ideas for two sample Lagrangians. The first system we examine
corresponds to that of a nonrelativistic particle in a scalar potential. The
other Lagrangian we consider is first order in time derivative
Computer Simulation of Structural Defects of Concrete Samples
This article discusses the issue of the effectiveness of using computer simulation in the study of the deformation characteristics of concrete. An analytical review of the works, the authors of which were used computer simulation tools. The complex computer-aided modelling of the structure of concrete was considered using the programs VCCTL, MSC.NASTRAN, SolidWorks, ANSYS. Improving the methods of computer modelling of the behavior of structures made of composite materials will allow to optimize their resistance to destruction, strength, attrition resistance and other parameters
Оценка уникальности популяций Bufo Viridis (Amphibia: Anura) с точки зрения рациональной экологической этики
Substantive provisions of rational environmental ethics are stated. This concept presumes to compare a level of uniqueness of different objects, which forms the establishment for giving the ethical value. The developed approach is used for comparison of 26 populations of Bufo viridis Laurenti, 1768 from Left-bank forest-steppe of Ukraine. Узагальнено основні положення раціональної екологічної етики. Ця концепція може дозволити порівнювати рівень унікальності різних об’єктів, стати основою для визнання їх етичної цінності. Даний підхід застосований для порівняння 26 популяцій зеленої ропухи (Bufo viridis Laurenti, 1768) з Лівобережного Лісостепу України. Узагальнено основні положення раціональної екологічної етики. Ця концепція може дозволити порівнювати рівень унікальності різних об’єктів, стати основою для визнання їх етичної цінності. Даний підхід застосований для порівняння 26 популяцій зеленої ропухи (Bufo viridis Laurenti, 1768) з Лівобережного Лісостепу України.
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