354 research outputs found

    Bifurcation in Rotational Spectra of Nonlinear AB2_2 Molecules

    Full text link
    A classical microscopic theory of rovibrational motion at high angular momenta in symmetrical non-linear molecules AB2_2 is derived within the framework of small oscillations near the stationary states of a rotating molecule. The full-dimensional analysis including stretching vibrations has confirmed the existence of the bifurcation predicted previously by means of the rigid-bender model. The formation of fourfold energy clusters has already been experimentally verified for H2_2Se and it has been demonstrated in fully-dimensional quantum mechanical calculations using the MORBID computer program. We show in the present work that apart from the level clustering, the bifurcation produces physically important effects including molecular symmetry-breaking and a transition from the normal mode to the local mode limit for the stretching vibrations due to rovibrational interaction. The application of the present theory with realistic molecular potentials to the H2_2Te, H2_2Se and H2_2S hydrides results in predictions of the bifurcation points very close to those calculated previously. However for the lighter H2_2O molecule we find that the bifurcation occurs at higher values of the total angular momentum than obtained in previous estimations. The present work shows it to be very unlikely that the bifurcation in H2_2O will lead to clustering of energy levels. This result is in agreement with recent variational calculations.Comment: latex, 19 pages including 2 figures provided as *.uu fil

    Automated matching of high- and low-resolution structural models

    Full text link

    ASSA

    Full text link

    Mycobacterium avium-intracellulare cellulitis occurring with septic arthritis after joint injection: a case report

    Get PDF
    BACKGROUND: Cellulitis caused by Mycobacterium avium-intracellulare has rarely been described. Mycobacterium avium-intracellulare is a rare cause of septic arthritis after intra-articular injection, though the causative role of injection is difficult to ascertain in such cases. CASE PRESENTATION: A 57-year-old with rheumatoid arthritis treated with prednisone and azathioprine developed bilateral painful degenerative shoulder arthritis. After corticosteroid injections into both acromioclavicular joints, he developed bilateral cellulitis centered over the injection sites. Skin biopsy showed non-caseating granulomas, and culture grew Mycobacterium avium-intracellulare. Joint aspiration also revealed Mycobacterium avium-intracellulare infection. CONCLUSION: Although rare, skin and joint infections caused by Mycobacterium avium-intracellulare should be considered in any immunocompromised host, particularly after intra-articular injection. Stains for acid-fast bacilli may be negative in pathologic samples even in the presence of infection; cultures of tissue specimens should always be obtained

    Dynamics of spin polarization in tilted polariton rings

    Get PDF
    This is an accepted manuscript of an article published by the American Physical Society in Physical Review B on 22/04/2021, available online: https://doi.org/10.1103/PhysRevB.103.165306 The accepted version of the publication may differ from the final published version.We have observed the effect of pseudomagnetic field originating from the polaritonic analog of spin-orbit coupling [transverse electric and transverse magnetic (TE-TM) splitting] on a polariton condensate in a ring-shaped microcavity. The effect gives rise to a stable four-leaf pattern around the ring as seen from the linear polarization measurements of the condensate photoluminescence. This pattern is found to originate from the interplay of the cavity potential, energy relaxation, and TE-TM splitting in the ring. Our observations are compared to the dissipative one-dimensional spinor Gross-Pitaevskii equation with the TE-TM splitting energy, which shows good qualitative agreement.Published versio

    Modern technology and the international copyright protection system: keeping a barrier between the freedom od knowledge and the freedom of privacy

    Get PDF
    Kozin A. B. Modern technology and the international copyright protection system: keeping a barrier between the freedom od knowledge and the freedom of privacy / A. B. Kozin, A. V. Zadereiko, F. M. Behmatova // Альманах міжнародного права. Вип. 6. - Одеса, 2014. - С. 127-132.This article focuses on the international copyright protection system and how it interacts with intellectual property. The unresolved problems of modern jurisprudence, the question of a fair balance between the right to freedom of information and protection of intellectual property rights is one of the most pressing issues in international policy. This is why it is such a big issue in the scientific community. It talks about keeping a steady balance between freedom of privacy and freedom of information. Internet, allowing to create and share information from anywhere in the world. It has radically changed relations, making material the product of its creator, publisher, and distributor. An effective system of intellectual property protection helps to create a civilized environment where entrepreneurs, and consumers would be protected from unauthorized use of intellectual property. Balancing the interests of rights holders and the rest of society is recognized as a fundamental aspect in the field of intellectual property. This meeting was set up to formally introduce Ukrainian judges to copyright information and to produce recommendations for future cases. Modern jurisprudence's unresolved problems are also discussed in relation to Ukraine and the changes that are being made to make these copyright laws to be more effective.Эта статья посвящена взаимодействию международной системы защиты авторских прав с интеллектуальной собственностью. Проблема сохранения устойчивого баланса между информационной свободой и её должной защитой. Вопросы мировой и, в частности, украинской юриспруденции в контексте современности.Ця стаття присвячена взаємодії міжнародної системи захисту авторських прав з інтелектуальною власністю. Проблема збереження стійкого балансу між інформаційною свободою і її належним захистом. Питання світової і, зокрема, української юриспруденції в контексті сучасності

    The HiSCORE Project

    Get PDF
    A central question of Astroparticle Physics, the origin of cosmic rays, still remains unsolved. HiSCORE (Hundred*i Square-km Cosmic ORigin Explorer) is a concept for a large-area wide-angle non-imaging air shower detector, addressing this question by searching for cosmic ray pevatrons in the energy range from 10TeV to few PeV and cosmic rays in the energy range above 100TeV. In the framework of the Tunka-HiSCORE project, first prototypes have been deployed on the site of the Tunka-133 experiment, where we plan to install an engineering array covering an area of the order of 1km2. On the same site, also imaging and particle detectors are planned, potentially allowing a future hybrid detector system. Here we present the HiSCORE detector principle, its potential for cosmic ray origin search and the status of ongoing activities in the framework of the Tunka-HiSCORE experiment

    Structures of the Signal Recognition Particle Receptor from the Archaeon Pyrococcus furiosus: Implications for the Targeting Step at the Membrane

    Get PDF
    In all organisms, a ribonucleoprotein called the signal recognition particle (SRP) and its receptor (SR) target nascent proteins from the ribosome to the translocon for secretion or membrane insertion. We present the first X-ray structures of an archeal FtsY, the receptor from the hyper-thermophile Pyrococcus furiosus (Pfu), in its free and GDP•magnesium-bound forms. The highly charged N-terminal domain of Pfu-FtsY is distinguished by a long N-terminal helix. The basic charges on the surface of this helix are likely to regulate interactions at the membrane. A peripheral GDP bound near a regulatory motif could indicate a site of interaction between the receptor and ribosomal or SRP RNAs. Small angle X-ray scattering and analytical ultracentrifugation indicate that the crystal structure of Pfu-FtsY correlates well with the average conformation in solution. Based on previous structures of two sub-complexes, we propose a model of the core of archeal and eukaryotic SRP•SR targeting complexes
    corecore