589 research outputs found

    Spin dependence of ferroelectric polarization in the double exchange model for manganites

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    The double exchange (DE) model is systematically applied for studying the coupling between ferroelectric (FE) and magnetic orders in several prototypical types of multiferroic manganites. The model was constructed for the magnetically active Mn 3d3d bands in the basis of Wannier functions and include the effect of screened on-site Coulomb interactions. The essence of our approach for the FE polarization is to use the Berry phase theory, formulated in terms of occupied Wannier functions, and to evaluate the asymmetric spin-dependent change of these functions in the framework of the DE model. This enables us to quantify the effect of the magnetic symmetry breaking and derive several useful expressions for the electronic polarization P{\bf P}, depending on the relative directions of spins. The proposed theory is applied to the solution of three major problems: (i) The magnetic-state dependence of P{\bf P} in hexagonal manganites; (ii) The microscopic relationship between canted ferromagnetism and P{\bf P} in monoclinic BiMnO3_3; (iii) The origin of FE activity in orthorhombic manganites. We show that for an arbitrary noncollinear magnetic structure, propagating along the orthorhombic b\boldsymbol{b} axis and antiferromagnetically coupled c\boldsymbol{c}, P{\bf P} can be obtained by scaling the one of the E-phase with the prefactor depending only on the relative directions of spins and being the measure of the spin inhomogeneity. This picture works equally well for the twofold (HoMnO3_3) and fourfold (TbMnO3_3) periodic manganites. The basic difference is that the twofold periodic magnetic structure is strongly inhomogeneous, that leads to large P{\bf P}. On the contrary, the fourfold periodic magnetic structure can be viewed as a moderately distorted homogeneous spin spiral, which corresponds to weaker P{\bf P}.Comment: 32 pages, 7 figure

    Confirmation of low genetic diversity and multiple breeding females in a social group of Eurasian badgers from microsatellite and field data

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    The Eurasian badger ( Meles meles ) is a facultatively social carnivore that shows only rudimentary co-operative behaviour and a poorly defined social hierarchy. Behavioural evidence and limited genetic data have suggested that more than one female may breed in a social group. We combine pregnancy detection by ultrasound and microsatellite locus scores from a well-studied badger population from Wytham Woods, Oxfordshire, UK, to demonstrate that multiple females reproduce within a social group. We found that at least three of seven potential mothers reproduced in a group that contained 11 reproductive age females and nine offspring. Twelve primers showed variability across the species range and only five of these were variable in Wytham. The microsatellites showed a reduced repeat number, a significantly higher number of nonperfect repeats, and moderate heterozygosity levels in Wytham. The high frequency of imperfect repeats and demographic phenomena might be responsible for the reduced levels of variability observed in the badger

    Three-point correlator of twist-2 light-ray operators in N=4 SYM in BFKL approximation

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    We present calculation of the correlation function of three twist-2 operators in the BFKL limit. The calculation is performed in N = 4 SYM but the result is valid in other gauge theories such as QCD. The obtained leading order structure constant is exact for any number of colors.Comment: 24 pages, 4 figures. arXiv admin note: text overlap with arXiv:1506.0203

    Anion permselective membrane

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    The efforts on the synthesis of polymer anion redox membranes were mainly concentrated in two areas, membrane development and membrane fabrication. Membrane development covered the preparation and evaluation of experimental membranes systems with improved resistance stability and/or lower permeability. Membrane fabrication covered the laboratory scale production of prime candidate membranes in quantities of up to two hundred and sizes up to 18 inches x 18 inches (46 cm x 46 cm). These small (10 in x 11 in) and medium sized membranes were mainly for assembly into multicell units. Improvements in processing procedures and techniques for preparing such membrane sets lifted yields to over 90 percent

    Narratology in Early Modern medical manuscripts: The Case of London, Wellcome Library, MS 213

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    It has been argued that narrative elements can be found throughout the history of English scientific writing. Narratives can be linked to specific genres; thus, learned texts for medical doctors were different from those directed to lay audiences (Taavitsainen, 2022). This article sets out to analyse a specific type of medical narrative, that of recipe collections, focusing for the purpose on the text housed in London, Wellcome Library, MS 213. The manuscript dates from the beginning of the seventeenth century (1606, more specifically) and gathers recipes “experienced and tryed by the speciall practize of Mrs Corlyon” (Moorat, 1962-1973).[1] The codex belonged to Alethea Howard (nĂ©e Talbot), Countess of Arundel. The main aim of the study is to identify and examine narrative forms and functions as well as particular features in the collection of recipes held in MS Wellcome 213, which can contribute to the knowledge of recipes written by and for women during the early modern period.Se ha afirmado que pueden encontrarse elementos narrativos a lo largo de la historia de la escritura cientĂ­fica inglesa. Las narrativas pueden estar vinculadas a gĂ©neros especĂ­ficos; asĂ­, los textos eruditos para mĂ©dicos eran diferentes de los dirigidos al gran pĂșblico (Taavitsainen, 2022). Este artĂ­culo se propone analizar un tipo especĂ­fico de narrativa mĂ©dica, el de las colecciones de recetas, centrĂĄndose para ello en el texto conservado en Londres, Wellcome Library, MS 213. El manuscrito data de principios del siglo XVII (1606, mĂĄs concretamente) y recoge recetas "experimentadas y probadas por la speciall practize de Mrs Corlyon" (Moorat, 1962-1973)[1]. El cĂłdice perteneciĂł a Alethea Howard (de soltera Talbot), condesa de Arundel. El objetivo principal del estudio es identificar y examinar las formas y funciones narrativas, asĂ­ como las caracterĂ­sticas particulares de la colecciĂłn de recetas conservadas en el MS Wellcome 213, que pueden contribuir al conocimiento de las recetas escritas por y para mujeres durante el perĂ­odo moderno temprano.S'ha afirmat que es poden trobar elements narratius al llarg de la histĂČria de l'escriptura cientĂ­fica anglesa. Les narratives poden estar vinculades a gĂšneres especĂ­fics; aixĂ­, els textos erudits per a metges eren diferents dels adreçats al pĂșblic general (Taavitsainen, 2022). Aquest article es proposa analitzar un tipus especĂ­fic de narrativa mĂšdica, el de les col·leccions de receptes, centrant-se en el text conservat a Londres, Wellcome Library, MS 213. El manuscrit data de principis del segle XVII (1606, mĂ©s concretament) i recull receptes “experimentades i provades per la speciall practize de Mrs Corlyon” (Moorat, 1962-1973)[1]. El cĂČdex va pertĂ nyer a Alethea Howard (de soltera Talbot), comtessa d'Arundel. L'objectiu principal de l'estudi Ă©s identificar i examinar les formes i funcions narratives, aixĂ­ com les caracterĂ­stiques particulars de la col·lecciĂł de receptes conservades al MS Wellcome 213, que poden contribuir al coneixement de les receptes escrites per i per a dones durant el perĂ­ode modern d'hora .The present research has been funded by the Spanish Ministry of Economy and Competitiveness (grant numbers FFI2014-57963-P and FFI2017-88060-P) and by the Andalusian Regional Government (grant number P11-HUM-7597).These grants are hereby gratefully acknowledged

    W213 Sencorℱ Tolerance Ratings for Selected Wheat Varieties

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    Bluegrass (aka Poa) and broadleaf winter annuals like henbit have caused serious yield loss in some wheat fields the last several years. In cases where these weeds were a problem, they became established before or with the wheat. If Poa or henbit becomes established with the wheat, it can deter tillering and readily compete for nitrogen. One way to manage these weeds is to apply Sencor at 3 to 4 oz/a postemergence over the wheat that is at 2 to 41f. This timing of a Sencor application has been a very inexpensive way to manage bluegrass and broadleaf weeds like henbit. Unfortunately, through the years, some wheat varieties have been prone to injury from a Sencor application. The Sencor label contains a list of sensitive wheat varieties. However, it is dated and not one variety on the current Sencor label is grown in Tennessee. More worrisome is that no wheat variety currently grown has been tested for sensitivity to Sencor by the seed companies. As a result, over the past two years we went to the county wheat trials and sprayed a 10-foot boom width of 4 and 16 oz/A Sencor across the back side. We then rated the varieties in the test for tolerance to Sencor. This work was conducted in Tennessee and Arkansas. The Sencor tolerance ratings are listed as T = tolerant, MT = moderately tolerant, MS = moderately susceptible and S = susceptible. The next column on the chart lists the number of observations. The more number of observations, the more confident a producer should be in the rating. Varieties that have less than four observations should be read with caution. In general, varieties listed with a T or MT have shown good tolerance to Sencor. Growers should be cautious about using Sencor on varieties rated with a MS grown on coarse soil types. Wheat growers should avoid using Sencor on varieties rated S for Sencor tolerance

    Results of the IGEC-2 search for gravitational wave bursts during 2005

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    The network of resonant bar detectors of gravitational waves resumed coordinated observations within the International Gravitational Event Collaboration (IGEC-2). Four detectors are taking part in this collaboration: ALLEGRO, AURIGA, EXPLORER and NAUTILUS. We present here the results of the search for gravitational wave bursts over 6 months during 2005, when IGEC-2 was the only gravitational wave observatory in operation. The network data analysis implemented is based on a time coincidence search among AURIGA, EXPLORER and NAUTILUS, keeping the data from ALLEGRO for follow-up studies. With respect to the previous IGEC 1997-2000 observations, the amplitude sensitivity of the detectors to bursts improved by a factor about 3 and the sensitivity bandwidths are wider, so that the data analysis was tuned considering a larger class of detectable waveforms. Thanks to the higher duty cycles of the single detectors, we decided to focus the analysis on three-fold observation, so to ensure the identification of any single candidate of gravitational waves (gw) with high statistical confidence. The achieved false detection rate is as low as 1 per century. No candidates were found.Comment: 10 pages, to be submitted to Phys. Rev.

    Cross-Protective Potential of a Novel Monoclonal Antibody Directed against Antigenic Site B of the Hemagglutinin of Influenza A Viruses

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    The hemagglutinin (HA) of influenza A viruses has been classified into sixteen distinct subtypes (H1–H16) to date. The HA subtypes of influenza A viruses are principally defined as serotypes determined by neutralization or hemagglutination inhibition tests using polyclonal antisera to the respective HA subtypes, which have little cross-reactivity to the other HA subtypes. Thus, it is generally believed that the neutralizing antibodies are not broadly cross-reactive among HA subtypes. In this study, we generated a novel monoclonal antibody (MAb) specific to HA, designated MAb S139/1, which showed heterosubtypic cross-reactive neutralization and hemagglutination inhibition of influenza A viruses. This MAb was found to have broad reactivity to many other viruses (H1, H2, H3, H5, H9, and H13 subtypes) in enzyme-linked immunosorbent assays. We further found that MAb S139/1 showed neutralization and hemagglutination-inhibition activities against particular strains of H1, H2, H3, and H13 subtypes of influenza A viruses. Mutant viruses that escaped neutralization by MAb S139/1 were selected from the A/Aichi/2/68 (H3N2), A/Adachi/2/57 (H2N2), and A/WSN/33 (H1N1) strains, and sequence analysis of the HA genes of these escape mutants revealed amino acid substitutions at positions 156, 158, and 193 (H3 numbering). A molecular modeling study showed that these amino acids were located on the globular head of the HA and formed a novel conformational epitope adjacent to the receptor-binding domain of HA. Furthermore, passive immunization of mice with MAb S139/1 provided heterosubtypic protection. These results demonstrate that MAb S139/1 binds to a common antigenic site shared among a variety of HA subtypes and neutralizes viral infectivity in vitro and in vivo by affecting viral attachment to cells. The present study supports the notion that cross-reactive antibodies play some roles in heterosubtypic immunity against influenza A virus infection, and underscores the potential therapeutic utility of cross-reactive antibodies against influenza