727 research outputs found

    Homogeneous singularities inside collapsing wormholes

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    We analyze analytically and numerically the origin of the singularity in the course of the collapse of a wormhole with the exotic scalar field Psi with negative energy density, and with this field Psi together with the ordered magnetic field H. We do this under the simplifying assumptions of the spherical symmetry and that in the vicinity of the singularity the solution of the Einstein equations depends only on one coordinate (the homogeneous approximation). In the framework of these assumptions we found the principal difference between the case of the collapse of the ordinary scalar field Phi with the positive energy density together with an ordered magnetic field H and the collapse of the exotic scalar field Psi together with the magnetic field H. The later case is important for the possible astrophysical manifestation of the wormholes.Comment: 10 pages, 5 figures each of which has a),b),c),and d) sub-figures. To be published in "Physical review. D, Particles, fields, gravitation, and cosmology

    Vacuum Squeezing in Atomic Media via Self-Rotation

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    When linearly polarized light propagates through a medium in which elliptically polarized light would undergo self-rotation, squeezed vacuum can appear in the orthogonal polarization. A simple relationship between self-rotation and the degree of vacuum squeezing is developed. Taking into account absorption, we find the optimum conditions for squeezing in any medium that can produce self-rotation. We then find analytic expressions for the amount of vacuum squeezing produced by an atomic vapor when light is near-resonant with a transition between various low-angular-momentum states. Finally, we consider a gas of multi-level Rb atoms, and analyze squeezing for light tuned near the D-lines under realistic conditions.Comment: 10 pages, 6 figures; Submitted to PR

    THE METHOD FOR DETERMINING THE ABSOLUTE CONFIGURATION USING NSUBSTITUTED CYCLIC AMINO ACIDS

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    Determining the absolute configuration of biologically active chiral substances is a current issue in drug development since biological properties of enantiomers may greatly vary. The absolute configuration of enantiomers can be determined using crystallography, circular dichroism, or by the method that involves chiral derivatizing agents and analysis of NMR spectra.This work was supported by the Russian Science Foundation, project no. 16-13-10358

    Inverse Spectral-Scattering Problem with Two Sets of Discrete Spectra for the Radial Schroedinger Equation

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    The Schroedinger equation on the half line is considered with a real-valued, integrable potential having a finite first moment. It is shown that the potential and the boundary conditions are uniquely determined by the data containing the discrete eigenvalues for a boundary condition at the origin, the continuous part of the spectral measure for that boundary condition, and a subset of the discrete eigenvalues for a different boundary condition. This result extends the celebrated two-spectrum uniqueness theorem of Borg and Marchenko to the case where there is also a continuous spectru

    Buffer-gas induced absorption resonances in Rb vapor

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    We observe transformation of the electromagnetically induced transparency (EIT) resonance into the absorption resonance in a Λ\Lambda interaction configuration in a cell filled with 87^{87}Rb and a buffer gas. This transformation occurs as a one-photon detuning of the coupling fields is varied from the atomic transition. No such absorption resonance is found in the absence of a buffer gas. The width of the absorption resonance is several times smaller than the width of the EIT resonance, and the changes of absorption near these resonances are about the same. Similar absorption resonances are detected in the Hanle configuration in a buffered cell.Comment: 11 pages, 15 figures; 13 pages, 17 figures, added numerical simulatio

    Constitutional and legal regulation of state authority interaction on citizen appeals: foreign experience

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    The purpose of this article is to identify the foreign experience of constitutional legalization of the basic foundations of interaction between government bodies regarding citizens' appeals. The study was built based on a dialectical approach to the disclosure of legal phenomena and processes using general scientific (systemic, logical, analysis and synthesis) and private scientific method

    Heart myxoma under the mask of interstitial lung lesion: a difficult case from practice

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    The aim of the investigation was to describe a clinical case of the development of interstitial lung lesions in a 57-year-old man with a large left atrial myxoma, which had a reverse development after myxomectomy.Materials and methods. Patient V., 57 years old, was hospitalized in the therapeutic department of the City Clinical Hospital No. 1 named after N. I. Pirogov in connection with bilateral polysegmental pneumonia. A month before hospitalization, he underwent an outpatient examination for progressive dyspnea. Myxoma of the heart was diagnosed. Due to the progression of respiratory failure and the appearance of fever, he was hospitalized. Amidst the multistage antibiotic therapy, there was a torpid course of lung pathology with syndromes of bilateral dissemination and “ground glass”, bilateral lymphadenopathy of the mediastinum, high pulmonary hypertension, and systemic inflammatory reaction syndrome. Thromboembolism of the branches of the pulmonary artery, tuberculosis, sepsis, infective endocarditis, neoplastic processes of pulmonary and other localization were excluded.Results. The clinical picture corresponded to interstitial lung lesions within the framework of paraneoplastic syndrome in heart myxoma. It was decided to urgently carry out myxomectomy.Conclusion. The clinical case demonstrates the development of a rare variant of paraneoplastic syndrome in left atrial myxoma, which was suspected during the patient’s treatment for bilateral polysegmental pneumonia. The progression of the pulmonary lesion was explained by active interstitial inflammation and was supported by the immunological activity of the heart tumor.The performed myxomectomy, despite the persisting syndrome of systemic inflammatory reaction and infiltration of the lung tissue, led in 2 weeks to complete resolution of interstitial lung lesions and pulmonary hypertension, which confirmed the causal relationship between myxoma of the heart and involvement in the pathological process of the lungs

    Commitment of Parents and Doctors of Irkutsk City to Vaccination against Tick-Borne Encephalitis

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    Today in Irkutsk region, we face a noticeable increase in the number of cases of ixodid tick sucking to urban residents. Ticks, found in the territory of Irkutsk city, were detected to have all currently known pathogens causing such serious diseases as tick-borne encephalitis, tick-borne borreliosis, monocytic ehrlichiosis, granulocytic anaplasmosis, rickettsiosis and tick-borne recurrent fever. These diseases may develop to severe  forms, and lead to disability or even death.  The aim of the study was to evaluate the opinion of parents and doctors on vaccination against tick-borne viral encephalitis in Irkutsk based on the data of an anonymous questionnaire survey.Material and methods. The descriptive retrospective epidemiological study was conducted between November 2018 and January 2019. It included 1620 parents and 193 doctors of various specialties in Irkutsk. Statistical processing of the material was carried out using Excel tables (Windows 2010) and the Statistica 6.0 program.Results and discussion. In general, the attitude towards vaccination looks positive – 98 % of the parents vaccinate their children. 11.3 % of parents vaccinate their children from tick-borne encephalitis, 23.3 % of doctors vaccinate themselves. Every fourth doctor vaccinates his child against this infection.Conclusion. Insufficient vaccination coverage against tick-borne encephalitis is noted both among the population and among doctors of Irkutsk. It is important to introduce health education for the population and to adopt new ways for improving the qualifications of doctors in immunization issues

    Comparative analysis of the legal status of testamentary foundations in Russia and foreign countries

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    Legal rules on a testamentary foundation are a novelty for Russian legislation. Since there were no analogues of this legal institution in Russia before, many law enforcement problems arise. Russian testamentary foundations have largely adopted the provisions on the foundations of the continental legal system. For a better understanding of the legal nature of this subject of law and solving law enforcement problems, it is necessary to analyze the legal status of testamentary foundations in the states where they have existed for a long time, and take into account the positive foreign experienc
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