Coherent control of the cooperative branching ratio for nuclear x-ray pumping

Coherent control of nuclear pumping in a three level system driven by x-ray light is investigated. In single nuclei, the pumping performance is determined by the branching ratio of the excited state populated by the x-ray pulse. Our results are based on the observation that in ensembles of nuclei, cooperative excitation and decay leads to a greatly modified nuclear dynamics, which we characterize by a time-dependent cooperative branching ratio. We discuss prospects of steering the x-ray pumping by coherently controlling the cooperative decay. First, we study an ideal case with purely superradiant decay and perfect control of the cooperative emission. A numerical analysis of x-ray pumping in nuclear forward scattering with coherent control of the cooperative decay via externally applied magnetic fields is presented. Next, we provide an extended survey of nuclei suitable for our scheme, and propose proof-of-principle implementations already possible with typical M\"ossbauer nuclear systems such as $^{57}\mathrm{Fe}$. Finally, we discuss the application of such control techniques to the population or depletion of long-lived nuclear states.Comment: 11 pages, 8 figures; updated to the published versio

Observations of Stellar Objects at a Shell Boundary in the Star-Forming Complex in the Galaxy IC1613

The single region of ongoing star formation in the galaxy IC 1613 has been observed in order to reveal the nature of compact emission-line objects at the edges of two shells in the complex, identified earlier in H-alpha line images. The continuum images show these compact objects to be stars. Detailed spectroscopic observations of these stars and the surrounding nebulae were carried out with an integral field spectrograph MPFS mounted on the 6m telescope of the Special Astrophysical Observatory. The resulting stellar spectra were used to determine the spectral types and luminosity classes of the objects. An Of star we identified is the only object of this spectral type in IC 1613. The results of optical observations of the multi-shell complex are compared to 21cm radio observations. The shells harboring the stars at their boundaries constitute the most active part of the star-forming region. There is evidence that shocks have played an important role in the formation of the shells.Comment: 10 pages, 5 PS and 1 color JPEG figur

Detection of an intergalactic meteor particle with the 6-m telescope

On July 28, 2006 the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences recorded the spectrum of a faint meteor. We confidently identify the lines of FeI and MgI, OI, NI and molecular-nitrogen N_2 bands. The entry velocity of the meteor body into the Earth's atmosphere estimated from radial velocity is equal to 300 km/s. The body was several tens of a millimeter in size, like chondrules in carbon chondrites. The radiant of the meteor trajectory coincides with the sky position of the apex of the motion of the Solar system toward the centroid of the Local Group of galaxies. Observations of faint sporadic meteors with FAVOR TV CCD camera confirmed the radiant at a higher than 96% confidence level. We conclude that this meteor particle is likely to be of extragalactic origin. The following important questions remain open: (1) How metal-rich dust particles came to be in the extragalactic space? (2) Why are the sizes of extragalactic particles larger by two orders of magnitude (and their masses greater by six orders of magnitude) than common interstellar dust grains in our Galaxy? (3) If extragalactic dust surrounds galaxies in the form of dust (or gas-and-dust) aureoles, can such formations now be observed using other observational techniques (IR observations aboard Spitzer satellite, etc.)? (4) If inhomogeneous extragalactic dust medium with the parameters mentioned above actually exists, does it show up in the form of irregularities on the cosmic microwave background (WMAP etc.)?Comment: 9 pages, 6 EPS figure

Modulational instability of bright solitary waves in incoherently coupled nonlinear Schr\"odinger equations

We present a detailed analysis of the modulational instability (MI) of ground-state bright solitary solutions of two incoherently coupled nonlinear Schr\"odinger equations. Varying the relative strength of cross-phase and self-phase effects we show existence and origin of four branches of MI of the two-wave solitary solutions. We give a physical interpretation of our results in terms of the group velocity dispersion (GVD) induced polarization dynamics of spatial solitary waves. In particular, we show that in media with normal GVD spatial symmetry breaking changes to polarization symmetry breaking when the relative strength of the cross-phase modulation exceeds a certain threshold value. The analytical and numerical stability analyses are fully supported by an extensive series of numerical simulations of the full model.Comment: Physical Review E, July, 199

Triplet p-wave superconductivity in low-density extended Hubbard model with Coulomb repulsion

We analyze superconducting instabilities in 3D and 2D extended Hubbard model with Coulomb repulsion between electrons on neighboring sites in the limit of low electron density ($n_{el} \rightarrow 0$) on simple cubic (square) lattice. We show that in a realistic strong-coupling case $U\gg V\gg W$ ($U$ and $V$ are the onsite and the intersite Coulomb repulsions, $W$ the bandwidth) the main SC instability corresponds to the p-wave pairing and in the leading order is correctly described by the equations obtained earlier in the absence of the intersite Coulomb interaction V=0.Comment: 6 pages, 4 figures, accepted for JETP Letter

The First Case of <I>Yersinia Pestis</I> Subsp. <I>Pestis</I> Isolation in the Territory of Altai Mountain Natural Plague Focus. Communication 1. Microbiological Characteristics, Molecular-Genetic and Mass-Spectrometric Identification of the Isolate

Performed is a complex microbiological, molecular-genetic and mass-spectrometric identification of Yersinia pestis main ssp. strain, which was isolated for the first time in the history of surveillance over the Altai mountain natural plague focus in June, 2012. Determined is its high universal virulence. Plasmid screening, multi-locus VNTR- and mass-spectrometric analyses have revealed the strain to be more closely related to the plague agent variant, circulating in the territory of the natural focus Khuukh-Serkh-Munkh-Khairkhan, Bayan-Ul’giisk aimak, Mongolia

Выявление Bordetella holmesii среди больных, госпитализированных в стационар с подозрением на коклюш или коклюшеподобные заболевания

Purpose. To reveal and estimate prevalence of B. holmesii among the patients hospitalized with suspicion pertussis and pertussis-like illnesses.Materials and methods. 424 clinical samples received from patients with of pertussis and pertussis-like illnesses in GBUZ IKB № 1 DZM in 2017–2018 are investigated. Identification of fragments of a genome of Bordetella was carried out in PCR-RT with “Amplisens® Bordetella multi-FL”. For identification of fragments of a genome of B. holmesii used PCR-RT with primers of IS481, IS1001 and hIS1001.Results. The research included 424 patients, from them 56,1% of children aged till 1 year, 41,3% of children – are more senior than 1 year and 2,6% of adults. When using test system 60,4% of the samples containing DNA of B. pertussis are revealed; 1,9% of samples – DNA of B. parapertussis; in 34,9% of samples it is received negative and in 2,8% – doubtful results. The research of 424 samples in PCR-RT by means of IS481, IS1001 and hIS1001 primers showed that 61,1% of samples contained DNA of B. pertussis; 0,7% of samples – DNA of B. parapertussis and 3,8% of samples – DNA of B. holmesii. In 143 samples the result was negative. From 16 DNA of B. holmesii – positive samples, 9 samples were negative in test system earlier, in 2 samples – the doubtful result, 1 sample was earlier identified as DNA of B. parapertussis and in 4 samples DNA of B. pertussis and B. holmesii are found.Conclusion. The research demonstrates circulation of B. holmesii in the territory of Russia that is confirmed by identification of positive samples in 3,8% of cases among the sick children and adults hospitalized in a hospital with suspicion of pertussis and pertussis-like illnesses. For increase in efficiency of laboratory confirmation of the clinical diagnosis of pertussis and pertussis-like illnesses the genodiagnostic of a pertussis is recommended to improve taking into account identification DNA of B. holmesii.Цель: выявить и оценить распространенность B. holmesii среди больных, госпитализированных в стационар с подозрением на коклюш и коклюшеподобные заболевания.Материалы и методы. Исследовано 424 пробы клинического материала от больных с подозрением на коклюш и коклюшеподобные заболевания, госпитализированных в Инфекционную клиническую больницу № 1 в 2017– 2018 гг. Выявление фрагментов генома бордетелл осуществляли в ПЦР-РВ с «АмплиСенс® Bordetella multi-FL». Для идентификации фрагментов генома B. holmesii использовали ПЦР-РВ с праймерами IS481, IS1001 и hIS1001. Результаты. В исследование включено 424 пациента, из них 57,6% детей до 1 года, 42,3% детей старше 1 года и 2,6% взрослых. При использовании тестсистемы обнаружено 60,4% образцов, содержащих ДНК B. pertussis; 1,9% образцов – ДНК B. parapertussis; в 34,9% образцов получен отрицательный и в 2,8% – сомнительный результаты. Исследование 424 образцов в ПЦР-РВ с помощью IS481, IS1001 и hIS1001 праймеров показало, что 61,1% образцов содержали ДНК B. pertussis; 0,7% образцов – ДНК В. parapertussis и 3,8% образцов – ДНК B. holmesii. В 143 образцах результат был отрицательным. Из 16 ДНК B. holmesii, 9 образцов ранее были отрицательными, в 2 образцах – сомнительный результат и 1 образец был ранее идентифицирован как ДНК B. parapertussis, в 4 образцах обнаружена ДНК B. pertussis и B. holmesii.Заключение. Исследование свидетельствует о циркуляции B. holmesii на территории России, что под тверждается выявлением положительных образцов в 3,8% случаев среди больных детей и взрослых, госпитализированных в стационар с подозрением на коклюш и коклюшеподобные заболевания. Для повышения эффективности лабораторного подтверждения клинического диагноза коклюша и коклюшеподобных заболеваний рекомендуется совершенствовать генодиагностику коклюшной инфекции с учетом идентификации ДНК B. holmesii