3,298 research outputs found

    Clover rot (Sclerotinia trifolium) and Fusarium fungi in organic red clover in Finland

    Get PDF
    Sclerotinia trifolium is economically one of the most important pathogens of red clover in Europe and North America, while many Fusarium species can cause root rot in red clover in certain environmental conditions. During the years 2003-2004 S. trifolium was found only in the Northern and Eastern part of Finland, although in 1960's it was common everywhere in Finland

    Electron-capture branch of 100Tc and tests of nuclear wave functions for double-beta decays

    Get PDF
    We present a measurement of the electron-capture branch of 100^{100}Tc. Our value, B(EC)=(2.6±0.4)×10−5B(\text{EC}) = (2.6 \pm 0.4) \times 10^{-5}, implies that the 100^{100}Mo neutrino absorption cross section to the ground state of 100^{100}Tc is roughly one third larger than previously thought. Compared to previous measurements, our value of B(EC)B(\text{EC}) prevents a smaller disagreement with QRPA calculations relevant to double-ÎČ\beta decay matrix elements

    INTEGRAL observations of the Large Magellanic Cloud region

    Full text link
    We present the preliminary results of the INTEGRAL survey of the Large Magellanic Cloud. The observations have been carried out in January 2003 (about 10^6 s) and January 2004 (about 4x10^5 s). Here we concentrate on the bright sources LMC X-1, LMC X-2, LMC X-3 located in our satellite galaxy, and on the serendipitous detections of the Galactic Low Mass X-ray Binary EXO 0748-676 and of the Seyfert 2 galaxy IRAS 04575-7537.Comment: 4 pages, 7 figures. To be published in the Proceedings of the 5th INTEGRAL Workshop: "The INTEGRAL Universe", February 16-20, 2004, Munic

    Reexamining the Lyman-Birge-Hopfield band of N2

    Get PDF
    Motivated by fundamental molecular physics and by atmospheric and planetary sciences, the valence excitations of N2 gas have seen several decades of intensive study, especially by electron-energy-loss spectroscopy (EELS). It was consequently surprising when a comparison of nonresonant inelastic x-ray scattering (NIXS) and nonresonant EELS found strong evidence for violations of the first Born approximation for EELS when leaving the dipole scattering limit. Here we reassess the relative strengths of the constituent resonances of the lowest-energy excitations of N2, encompassed by the so-called Lyman-Birge-Hopfield (LBH) band, expanding on the prior, qualitative interpretation of the NIXS results for N2 by both quantifying the generalized oscillator strength of the lowest-energy excitations and also presenting a time-dependent density functional theory (TDDFT) calculation of the q dependence of the entire low-energy electronic excitation spectrum. At high q, we find that the LBH band has an unexpectedly large contribution from the octupolar w 1Δu resonance exactly in the regime where theory and EELS experiment for the presumed-dominant a 1Πg resonance have previously had substantial disagreement, and also where the EELS results must now be expected to show violations of the Born approximation. After correcting for this contamination, the a 1Πg generalized oscillator strength from the NIXS results is in good agreement with prior theory. The NIXS spectra, over their entire q range, also find satisfactory agreement with the TDDFT calculations for both bound and continuum excitations.This work was supported by the US Department of Energy, the Natural Sciences and Engineering Research Council (NSERC) of Canada, the Australian Research Council, the Research Funds of the University of Helsinki, and the Academy of Finland (Contract No. 1127462, Centers of Excellence Program 2006-2011, and National Graduate School in Materials Physics). A.R. acknowledges support by MICINN (FIS2010-21282-C02-01),ACI-promociona (ACI2009-1036), Grupos Consolidados UPV/EHU del Gobierno Vasco (IT-319- 07), and the European Community through e-I3 ETSF project (Contract No. 211956).Peer Reviewe

    Drone Measurements of Solar-Induced Chlorophyll Fluorescence Acquired with a Low-Weight DFOV Spectrometer System

    Get PDF
    Solar induced chlorophyll fluorescence (SIF) emitted from plant canopies is now retrievable from space. In addition, SIF is now also routinely measured from fixed tower platforms. However there is a scale gap between temporally continuous tower measurements and spatially coarse satellite retrievals that is now being bridged by drone technology. Drone retrievals of SIF can be used to help unravel the structural and species component dependencies that occur across space on the scale of meters in heterogeneous vegetation types. Also when flown at sufficient altitude, drones can be used to simulate, and potentially validate satellite retrievals of SIF. We flew a dual field of view spectrometer system, the Piccolo doppio, above a boreal forest with the aim of retrieving SIF. Our flights were designed to assess both spatial heterogeneity of SIF driven by changes in vegetation cover type and to simulate satellite pixels by flying at a relatively high altitude.Peer reviewe

    Role of Pneumococcal NanA Neuraminidase Activity in Peripheral Blood

    Get PDF
    The most frequent form of hemolytic-uremic syndrome (HUS) is associated with infections caused by Shiga-like toxin-producing Enterohaemorrhagic Escherichia coli (STEC). In rarer cases HUS can be triggered by Streptococcus pneumoniae. While production of Shiga-like toxins explains STEC-HUS, the mechanisms of pneumococcal HUS are less well known. S. pneumoniae produces neuraminidases with activity against cell surface sialic acids that are critical for factor H-mediated complement regulation on cells and platelets. The aim of this study was to find out whether S. pneumoniae neuraminidase NanA could trigger complement activation and hemolysis in whole blood. We studied clinical S. pneumoniae isolates and two laboratory strains, a wild-type strain expressing NanA, and a NanA deletion mutant for their ability to remove sialic acids from various human cells and platelets. Red blood cell lysis and activation of complement was measured ex vivo by incubating whole blood with bacterial culture supernatants. We show here that NanA expressing S. pneumoniae strains and isolates are able to remove sialic acids from cells, and platelets. Removal of sialic acids by NanA increased complement activity in whole blood, while absence of NanA blocked complement triggering and hemolytic activity indicating that removal of sialic acids by NanA could potentially trigger pHUS.Peer reviewe

    Vacuum Rabi splitting and strong coupling dynamics for surface plasmon polaritons and Rhodamine 6G molecules

    Full text link
    We report on strong coupling between surface plasmon polaritons (SPP) and Rhodamine 6G (R6G) molecules, with double vacuum Rabi splitting energies up to 230 and 110 meV. In addition, we demonstrate the emission of all three energy branches of the strongly coupled SPP-exciton hybrid system, revealing features of system dynamics that are not visible in conventional reflectometry. Finally, in analogy to tunable-Q microcavities, we show that the Rabi splitting can be controlled by adjusting the interaction time between waveguided SPPs and R6G deposited on top of the waveguide. The interaction time can be controlled with sub-fs precision by adjusting the length of the R6G area with standard lithography methods.Comment: 4 pages, 4 figure

    X-ray Raman scattering study of aligned polyfluorene

    Full text link
    We present a non-resonant inelastic x-ray scattering study at the carbon K-edge on aligned poly[9,9-bis(2-ethylhexyl)-fluorene-2,7-diyl] and show that the x-ray Raman scattering technique can be used as a practical alternative to x-ray absorption measurements. We demonstrate that this novel method can be applied to studies on aligned π\pi-conjugated polymers complementing diffraction and optical studies. Combining the experimental data and a very recently proposed theoretical scheme we demonstrate a unique property of x-ray Raman scattering by performing the symmetry decomposition on the density of unoccupied electronic states into ss- and pp-type symmetry contributions.Comment: 19 pages, 8 figure
    • 

    corecore