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15a,wi119,to144,, Edyta,Jó,ź,wiak, Michał,Minta, Zenon,15a,mietanka, Krzysztof Springer US 2018 Virus genes Vol.54 No.1
<P>The study presents molecular characterization of H9N2 avian influenza (AI) isolates from field outbreaks in turkeys that occurred in Poland in 2013–2014. Sequences of all gene segments of one isolate from 2013 (A/turkey/Poland/14/2013(H9N2)) and two isolates from 2014 (A/turkey/Poland/08/2014(H9N2), A/turkey/Poland/09/2014(H9N2)) were obtained and analyzed in search of the phylogenetic relationship and molecular markers of zoonotic potential or increased pathogenicity. All gene segments were shown to originate from the wild bird reservoir and the close relationship of the analyzed isolates proved the link between the outbreaks in 2013 and 2014. However, remarkable molecular differences between isolates from 2013 to 2014 were identified, including mutation in the HA cleavage site (CS) leading to conversion from the PAAS<U>N</U>R*GLF to the PAAS<U>K</U>R*GLF motif and truncation of the PB1-F2 protein. Additionally, T97I substitution in the PA protein in A/turkey/Poland/08/2014 was detected which can be responsible for enhanced activity of viral polymerase in mammalian cells. However, experimental infection of mice with both isolates from 2014 showed their low pathogenicity, and no statistically significant differences in virus replication were observed between the viruses. Nevertheless, these findings indicate the dynamic evolution of H9N2 in the field emphasizing the need for monitoring of the situation in terms of H9N2 AI in Europe.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1007/s11262-017-1513-4) contains supplementary material, which is available to authorized users.</P>
New light‐travel time models and orbital stability study of the proposed planetary system HU Aquarii
Hinse, T. C.,Lee, J. W.,Goź,dziewski, K.,Haghighipour, N.,Lee, C.2010,U.,Scullion, E. M. Blackwell Publishing Ltd 2012 Monthly notices of the Royal Astronomical Society Vol.420 No.4
<P><B>ABSTRACT</B></P><P>In this work we propose a new orbital architecture for the two proposed circumbinary planets around the polar eclipsing binary HU Aquarii. We base the new two‐planet, light‐travel time model on the result of a Monte Carlo simulation driving a least‐squares Levenberg–Marquardt minimization algorithm on the observed eclipse egress times. Our best‐fitting model with <IMG src='/wiley-blackwell_img/equation/MNR_20283_mu1.gif' alt ='inline image'/> resulted in high final eccentricities for the two companions leading to an unstable orbital configuration. From a large ensemble of initial guesses, we examined the distribution of final eccentricities and semimajor axes for different <IMG src='/wiley-blackwell_img/equation/MNR_20283_mu2.gif' alt ='inline image'/> parameter intervals and encountered qualitatively a second population of best‐fitting parameters. The main characteristic of this population is described by low‐eccentric orbits favouring long‐term orbital stability of the system. We present our best‐fitting model candidate for the proposed two‐planet system and demonstrate orbital stability over one million years using numerical integrations.</P>
Omrani, A. A.,White, J. S.,Pr161,a, K.,d,ivkovi107,, I.,Berger, H.,Magrez, A.,Liu, Ye-Hua,Han, J. H.,Rønnow, H. M. American Physical Society 2014 Physical review. B, Condensed matter and materials Vol.89 No.6
Using superconducting quantum interference device magnetometry techniques, we have studied the change in magnetization versus applied ac electric field, i.e. the magnetoelectric (ME) susceptibility dM/dE, in the chiral-lattice ME insulator Cu2OSeO3. Measurements of the dM/dE response provide a sensitive and efficient probe of the magnetic phase diagram, and we observe clearly distinct responses for the different magnetic phases, including the skyrmion lattice phase. By combining our results with theoretical calculation, we estimate quantitatively the ME coupling strength as lambda = 0.0146 meV/(V/nm) in the conical phase. Our study demonstrates the ME susceptibility to be a powerful, sensitive, and efficient technique for both characterizing and discovering new multiferroic materials and phases.
Nonlinear localized flat-band modes with spin-orbit coupling
Gligori107,, G.,Maluckov, A.,Hade,ievski, Lj.,Flach, Sergej,Malomed, Boris A. American Physical Society 2016 Physical Review B Vol.94 No.14
<P>We report the coexistence and properties of stable compact localized states (CLSs) and discrete solitons (DSs) for nonlinear spinor waves on a flat-band network with spin-orbit coupling (SOC). The system can be implemented by means of a binary Bose-Einstein condensate loaded in the corresponding optical lattice. In the linear limit, the SOC opens a minigap between flat and dispersive bands in the system's band-gap structure, and preserves the existence of CLSs at the flat-band frequency, simultaneously lowering their symmetry. Adding on-site cubic nonlinearity, the CLSs persist and remain available in an exact analytical form, with frequencies that are smoothly tuned into the minigap. Inside of the minigap, the CLS and DS families are stable in narrow areas adjacent to the FB. Deep inside the semi-infinite gap, both the CLSs and DSs are stable too.</P>
THE STELLAR METALLICITY DISTRIBUTION FUNCTION OF THE GALACTIC HALO FROM SDSS PHOTOMETRY
An, Deokkeun,Beers, Timothy C.,Johnson, Jennifer A.,Pinsonneault, Marc H.,Lee, Young Sun,Bovy, Jo,Ivezi107,, d,eljko,Carollo, Daniela,Newby, Matthew IOP Publishing 2013 The Astrophysical journal Vol.763 No.1
<P>We explore the stellar metallicity distribution function of the Galactic halo based on SDSS ugriz photometry. A set of stellar isochrones is calibrated using observations of several star clusters and validated by comparisons with medium-resolution spectroscopic values over a wide range of metal abundance. We estimate distances and metallicities for individual main-sequence stars in the multiply scanned SDSS Stripe 82, at heliocentric distances in the range 5-8 kpc and |b| > 35 degrees, and find that the in situ photometric metallicity distribution has a shape that matches that of the kinematically selected local halo stars from Ryan & Norris. We also examine independent kinematic information from proper-motion measurements for high Galactic latitude stars in our sample. We find that stars with retrograde rotation in the rest frame of the Galaxy are generally more metal poor than those exhibiting prograde rotation, which is consistent with earlier arguments by Carollo et al. that the halo system comprises at least two spatially overlapping components with differing metallicity, kinematics, and spatial distributions. The observed photometric metallicity distribution and that of Ryan & Norris can be described by a simple chemical evolution model by Hartwick (or by a single Gaussian distribution); however, the suggestive metallicity-kinematic correlation contradicts the basic assumption in this model that the Milky Way halo consists primarily of a single stellar population. When the observed metallicity distribution is deconvolved using two Gaussian components with peaks at [Fe/H] approximate to -1.7 and -2.3, the metal-poor component accounts for approximate to 20%-35% of the entire halo population in this distance range.</P>
THE PROPOSED QUADRUPLE SYSTEM SZ HERCULIS: REVISED LITE MODEL AND ORBITAL STABILITY STUDY
Hinse, Tobias Cornelius,Goź,dziewski, Krzysztof,Lee, Jae Woo,Haghighipour, Nader,Lee, Chung-Uk American Institute of Physics 2012 The Astronomical journal Vol.144 No.2
<P>In a recent study, Lee et al. presented new photometric follow-up timing observations of the semidetached binary system SZ Herculis and proposed the existence of two hierarchical cirumbinary companions. Based on the light-travel time effect, the two low-mass M-dwarf companions are found to orbit the binary pair on moderate to high eccentric orbits. The derived periods of these two companions are close to a 2:1 mean-motion orbital resonance. We have studied the stability of the system using the osculating orbital elements as presented by Lee et al. Results indicate an orbit-crossing architecture exhibiting short-term dynamical instabilities leading to the escape of one of the proposed companions. We have examined the system's underlying model parameter space by following a Monte Carlo approach and found an improved fit to the timing data. A study of the stability of our best-fitting orbits also indicates that the proposed system is generally unstable. If the observed anomalous timing variations of the binary period is due to additional circumbinary companions, then the resulting system should exhibit a long-term stable orbital configuration much different from the orbits suggested by Lee et al. We, therefore, suggest that based on Newtonian-dynamical considerations, the proposed quadruple system cannot exist. To uncover the true nature of the observed period variations of this system, we recommend future photometric follow-up observations that could further constrain eclipse-timing variations and/or refine light-travel time models.</P>
St119,pniowski, Wojciech J.,Yoo, Hyeonseok,Choi, Jinsub,Norek, Małgorzata,Jó,ź,wik, Paweł,Misiolek, Wojciech Z. Elsevier 2019 THIN SOLID FILMS - Vol.671 No.-
<P><B>Abstract</B></P> <P>Electropolished copper foil was passivated in aqueous solution of 1.0 M NaOH at negative potential range vs. silver chloride electrode at room temperature. The passivations were performed at −50, −100, −150, and −200 mV for 1, 5 or 15 h. The resulting nano-needle layers were characterized by X-ray photoelectron spectroscopy and band gaps derived from UV–Vis spectroscopy evidencing coincidence of Cu(OH)<SUB>2</SUB>, CuO and Cu<SUB>2</SUB>O phases. Scanning Electron Microscopy revealed that the diameter of nanoneedles was not influenced by the passivation potential, however, the nanoneedles diameter was decreasing with extension of the passivation time (the smallest diameter obtained was 60 ± 17 nm). Additionally, the as-prepared oxide nano-needles were found to be polycrystalline, without any post treatments. All together, chemical compositionand physical properties (band gap) show that the inner part of the grown nano-needles is rather made of Cu<SUB>2</SUB>O, while outer part, there where the passivation reaction takes place, is made of CuO and Cu(OH)<SUB>2</SUB>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Copper was passivated in NaOH. </LI> <LI> Formed oxide was crystalline and made of nanoneedles. </LI> <LI> X-ray Photoelectron Spectroscopy shows presence of Cu<SUB>2</SUB>O, CuO and Cu(OH)<SUB>2.</SUB> </LI> <LI> Optical bandgap was found to be ca. 2.2 (Cu<SUB>2</SUB>O) and 1.4 eV (CuO). </LI> </UL> </P>