1,602 research outputs found

    On a low energy bound in a class of chiral field theories with solitons

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    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

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    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

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    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

    Weyl group, CP and the kink-like field configurations in the effective SU(3) gauge theory

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    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

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    We examine the problem of defining Lagrangian and Hamiltonian mechanics for a particle moving on a quantum plane Qq,pQ_{q,p}. For Lagrangian mechanics, we first define a tangent quantum plane TQq,pTQ_{q,p} spanned by noncommuting particle coordinates and velocities. Using techniques similar to those of Wess and Zumino, we construct two different differential calculi on TQq,pTQ_{q,p}. 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 TQq,pT^*Q_{q,p} 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 TQq,pT^*Q_{q,p}, 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

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    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

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    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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