1,035 research outputs found
Resolubility of Image-Potential Resonances
A theory of image-potential states is presented for the general case where
these surface electronic states are resonant with a bulk continuum. The theory
extends the multiple scattering approach of Echenique and Pendry into the
strong coupling regime while retaining independence from specific forms of
surface and bulk potentials. The theory predicts the existence of a
well-resolved series of resonances for arbitrary coupling strengths.
Surprisingly, distinct image-potential resonances are thus expected to exist on
almost any metal surface, even in the limiting case of jellium
Convergence of the method of reflections for particle suspensions in Stokes flows
We study the convergence of the method of reflections for the Stokes
equations in domains perforated by countably many spherical particles with
boundary conditions typical for the suspension of rigid particles. We prove
that a relaxed version of the method is always convergent in under a
mild separation condition on the particles. Moreover, we prove optimal
convergence rates of the method in , and in
in terms of the particle volume fraction under a stronger separation
condition of the particles.Comment: 25 pages; relaxed assumptions for Corollary 2.
Isolated photon and photon+jet production at NNLO QCD accuracy and the ratio
We discuss different approaches to photon isolation in fixed-order
calculations and present a new next-to-next-to-leading order (NNLO) QCD
calculation of , the ratio of the inclusive isolated photon
cross section at 8 TeV and 13 TeV, differential in the photon transverse
momentum, which was recently measured by the ATLAS collaboration.Comment: 4 pages, 1 figure. Contribution to the 2019 QCD session of the 54th
Rencontres de Morion
Breeding of resistant strawberry cultivars for organic fruit production – Diallel crossing strategies and resistance tests for Botrytis cinerea and Xanthomonas fragariae
Organic strawberry production suffers from high yield losses caused by numerous fungal and bacterial diseases. Two of the most important diseases are the grey mould disease caused by Botrytis cinerea Pers. (teleomorph Botryotinia fuckeliana), and the bacterial angular leaf spot disease caused by Xanthomonas fragariae (Kennedy & King). Beside cultivation methods and organic plant protection measures, the development of resistant cultivars seems to be the most promising strategy in order to improve the productivity in organic strawberry cultivation. Therefore, we established resistance tests to determine resistant and susceptible strawberry cultivars and breeding selections. In a first run, 40 different cultivars and selections were tested for their susceptibility towards B. cinerea by artificial inoculation of fruits and leaves and evaluation of the disease symptoms. Plants of 40 cultivars were tested for susceptibility to X. fragariae by artificial inoculation in the greenhouse. In a diallel crossing approach, 12 commonly cultivated strawberry cultivars have been crossed reciprocally and propagated in a field trial. Important characteristics of the progeny such as ripening time, yield, morphological traits and occurrence of diseases have been evaluated for a period of two consecutive years and lead to the determination of general (GCA) and specific (SCA) combining abilities. Together with the results of the resistance tests we identified a set of genotypes that show resistant characteristics towards B. cinerea and might be suitable for use in organic cultivation systems. Furthermore, they can be used for targeted breeding experiments in the future
Pair production and correlated decay of heavy Majorana neutrinos in e+e- collisions
We consider the process e^+e^-\to N_1N_2, where N_1 and N_2 are heavy Majorana particles, with relative CP given by \eta_{CP}=+1 or -1 decaying subsequently via N_1,N_2\to W^{\pm}e^{\mp}. We derive the energy and angle correlation of the dilepton final state, both for like-sign (e^{\mp}e^{\mp}) and unlike-sign (e^-e^+) configurations. Interesting differences are found between the cases \eta_{CP}=+1 and -1. The characteristics of unlike-sign e^+e^- dileptons originating from a Majorana pair N_1N_2 are contrasted with those arising from the reaction e^+e^-\to N\bar{N}\to W^+e^-W^-e^+, where N\bar{N} is a Dirac particle-antiparticle pair
Tpr1, a Schizosaccharomyces pombe protein involved in potassium transport
AbstractThe Schizosaccharomyces pombe Tpr1 was isolated as suppressor of the Saccharomyces cerevisiae Δ trk1,2 potassium uptake deficient phenotype. Tpr1, for tetratrico peptide repeat, encodes a 1039 amino acid residues protein with several reiterated TPR units displaying significant homology to p150TSP, a recently identified phosphoprotein of mouse, to S. cerevisiae CTR9 and to related sequences of human, Caenorhabditis elegans, Methanoccocus jannaschii and Arabidopsis thaliana. Expression of Tpr1 restored growth on 0.2 mM K+ media, induced K+ transport with a KT of 4.6 mM and resumed inward currents of −90 pÅ at −250 mV (pH 7.2) conducting K+ and other alkali-metal ions. The tetratrico peptide repeat is a degenerate motif of 34 amino acids that is repeated several times within TPR-containing proteins and has been suggested to mediate protein-protein interactions. The sequence and putative binding properties of Tpr1 suggest the protein unlikely as transporter but involved in the enhancement of K+ uptake via conventional carriers
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