3,639 research outputs found

    Higher bundle gerbes and cohomology classes in gauge theories

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    The notion of a higher bundle gerbe is introduced to give a geometric realization of the higher degree integral cohomology of certain manifolds. We consider examples using the infinite dimensional spaces arising in gauge theories.Comment: 16 pages, LaTe

    Parametric pumping at finite frequency

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    We report on a first principles theory for analyzing the parametric electron pump at a finite frequency. The pump is controlled by two pumping parameters with phase difference ϕ\phi. In the zero frequency limit, our theory predicts the well known result that the pumped current is proportional to sinâĄÏ•\sin\phi. For the more general situation of a finite frequency, our theory predicts a non-vanishing pumped current even when the two driving forces are in phase, in agreement with the recent experimental results. We present the physical mechanism behind the nonzero pumped current at ϕ=0\phi=0, which we found to be due to photon-assisted processes

    We-Intention to Use Instant Messaging for Collaboration: A Social Influence Model

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    The purpose of this study is to introduce the concept of “we-intention” into group technology adoption and diffusion research. In this study, we examined the “we-intention” of using instant messaging for team collaboration. Building upon the social influence framework, a we-intention model is developed and tested with 163 respondents. The research model explained 41.3% of the variance in we-intention. Attitude, group norm and social identity were found to be statistically significant in determining we-intention to use instant messaging for collaboration, and value perception had significant effects on attitude and social influence factors. We believe that the implications of this study are important for both researchers and practitioners

    Quantization of adiabatic pumped charge in the presence of superconducting lead

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    We investigate the parametric electron pumping of a double barrier structure in the presence of a superconducting lead. The parametric pumping is facilitated by cyclic variation of the barrier heights x1x_1 and x2x_2 of the barriers. In the weak coupling regime, there exists a resonance line in the parameter space (x1,x2)(x_1,x_2) so that the energy of the quasi-bound state is in line with the incoming Fermi energy. Levinson et al found recently that the pumped charge for each pumping cycle is quantized with Q=2eQ=2e for normal structure when the pumping contour encircles the resonance line. In the presence of a superconducting lead, we find that the pumped charge is quantized with the value 2e2e

    Identification of compounds with anti-human cytomegalovirus activity that inhibit production of IE2 proteins

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    Using a high throughput screening methodology we surveyed a collection of largely uncharacterized validated or suspected kinase inhibitors for anti-human cytomegalovirus (HCMV) activity. From this screen we identified three structurally related 5-aminopyrazine compounds (XMD7-1, -2 and -27) that inhibited HCMV replication in virus yield reduction assays at low micromolar concentrations. Kinase selectivity assays indicated that each compound was a kinase inhibitor capable of inhibiting a range of cellular protein kinases. Western blotting and RNA sequencing demonstrated that treatment of infected cells with XMD7 compounds resulted in a defect in the production of the major HCMV transcriptional transactivator IE2 proteins (IE2-86, IE2-60 and IE2-40) and an overall reduction in transcription from the viral genome. However, production of certain viral proteins was not compromised by treatment with XMD7 compounds. Thus, these novel anti-HCMV compounds likely inhibited transcription from the viral genome and suppressed production of a subset of viral proteins by inhibiting IE2 protein production

    Semiconductor-metal core-shell plasmonic nanolasers with a bowtie antenna cross section

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    A new plasmonic bowtie nanolaser structure is fabricated where a semiconductor gain core is enclosed by a metal shell with bowtie cross section built-in. Light emission characteristics under electrical injection will be reported

    Cylindrically Symmetric Inhomogeneous Universes with a Cloud of Strings

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    Cylindrically symmetric inhomogeneous string cosmological models are investigated in presence of string fluid as a source of matter. To get the three types of exact solutions of Einstein's field equations we assume A=f(x)k(t)A = f(x)k(t), B=g(x)ℓ(t)B = g(x)\ell(t) and C=h(x)ℓ(t)C = h(x)\ell(t). Some physical and geometric aspects of the models are discussed.Comment: 9 page

    Molecular markers and genomic resources for disease resistance in peanut-A review

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    Recent polyploidation of peanut genome and geographical isolation has rendered peanut to be a highly monomorphic species. Due to its narrow genetic base, cultivated peanut has been susceptible to various diseases, causing economic loss to farmers. Availability of only a few disease resistance sources in cultivated peanut has resulted in limited success using the conventional breeding practices. Also, scarcity of markers has been the major limiting factor to precisely identify the disease resistance genomic regions. Recent identification of large number of molecular markers using advanced genomic resources and high throughput sequencing technologies has and will continue to assist in improvement of peanut diversity and breeding. This review gives an update on recent discovery of molecular markers associated with major diseases and the available genomic resources in peanut
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