329 research outputs found

    A Detection Method for Tropical Race 4 of the Banana Pathogen Fusarium oxysporum f. sp. cubense

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    Fusarium oxysporum f. sp. cubense (Foc) is the causal agent of Fusarium wilt, the devastating disease that ruined the ‘Gros Michel’ (AAA)-based banana production in the first half of the 20th century. The occurrence of a new variant in Southeast Asia that overcomes the resistance in Cavendish clones such as ‘Grand Naine’ (AAA) is a major concern to current banana production worldwide. The threat posed by this new variant, called tropical race 4 (TR4), may be overcome by the introduction of resistant cultivars. However, the identification of new resistant sources or breeding for resistance is a long-term effort. Currently, the only option to control the disease is to avoid or reduce the spread of the pathogen by eradication of infected plants and isolation of infested plantations. This requires sensitive and highly specific diagnostics that enable early detection of the pathogen. A two-locus database of DNA sequences, from over 800 different isolates from multiple formae speciales of F. oxysporum, was used to develop a molecular diagnostic tool that specifically detects isolates from the vegetative compatibility group (VCG) 01213, which encompasses the Foc TR4 genotype. This diagnostic tool was able to detect all Foc TR4 isolates tested, while none of the Foc isolates from 19 VCGs other than 01213 showed any reaction. In addition, the developed diagnostic tool was able to detect Foc TR4 when using DNA samples from different tissues of ‘Grand Naine’ plants inoculated with TR4 isolate

    High-temperature oxygen non-stoichiometry, conductivity and structure in strontium-rich nickelates La2-xSrxNiO4-\delta (x = 1 and 1.4)

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    Oxygen nonstoichiometry, electrical conductivity and thermal expansion of La2 xSrxNiO4-\delta phases with high levels of strontium substitution (1 =< x =< 1.4) have been investigated in air and oxygen atmosphere in the temperature range 20-1050 degrees C. These phases retain the K2NiF4-type structure of La2NiO4 (tetragonal, space group I4/mmm). The oxygen vacancy fraction was determined independently from thermogravimetric and neutron diffraction experiments, and is found to increase considerably on heating. The electrical resistivity, thermal expansion and cell parameters with temperature show peculiar variations with temperature, and differ notably from La2NiO4±\pm\delta in this respect. These variations are tentatively correlated with the evolution of nickel oxidation state, which crosses from a Ni3+/Ni4+ to a Ni2+/Ni3+ equilibrium on heating

    Surgical treatment of theintersex condition in the dog

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    Intersexuality is a rare congenital condition that leads to the development of an ambiguous urogenital tract. Removal of the reproductive tract is recommended to avoid genital diseases; however there is scant information about the procedure. The objective of this report is to describe the surgical procedure used to treat the canine intersex condition. Surgical corrections were performed on four intersex dogs: three 78 XX SRY-negative (one bilateral ovotestis, two sertolicell-only syndrome) and one 78 XX SRY-positive (sertolicell-only syndrome). Despite the different genetic and histological features, the anatomical characteristics were similar. The patients presented a vulva that lacked of dorsal fold placed ventrocranially to its anatomically normal position, a hypertrophied os clitoris protruding from the vulva and a urinary opening near to its normal position in the bitch..

    Fenugreek proteins and their hydrolysates prevent hypercholesterolemia and enhance the HDL antioxidant properties in rats

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    Purpose This paper aims to investigate the in vivo hypocholesterolemic property of fenugreek proteins (FP), Purafect-fenugreek protein hydrolysate (PFPH) and Esperase-fenugreek protein hydrolysate (EFPH) on high cholesterol (HC)-fed rats. Design/methodology/approach Rats were randomized into five groups: four were fed for four weeks a hypercholesterolemic diet and the tested products were given by gavage. The fifth group was taken as control (C) receiving the same diet without cholesterol. Findings Results showed that the elevated aspartate aminotransferase activity in HC group plasma was significantly corrected by FP and EFPH administration (-33 per cent; p = 0.0003). HC liver lipids and total cholesterol (TC) contents were not markedly affected by FP and EFPH. However, liver triglycerides (TG) contents trended to decrease in FP rats vs HC (p = 0.07), while, the TG decrease was significant in groups fed the proteins hydrolysates (p = 0.02). On the other hand, serum TC and TG decreased by 53 per cent (p = 0.0003) and 20 per cent (p = 0.04), respectively, in FP treated rats compared to HC group. This decrease was associated with a high fecal cholesterol excretion (2.5-fold higher in FP vs HC; p = 0.0001). Likewise, EFPH-treated rats exhibited lower TC compared to HC rats (p = 0.004). The very low density lipoprotins was the main affected fraction in these two groups, while there were no significant difference in apolipoproteins (Apo) B, A-I and A-IV contents between the different groups, except in FP group, where Apo A-I and A-IV decreased by 26 and 17 per cent, respectively, compared to C rats (p = 0.02). The high density lipoproteins (HDL) of rats treated with proteins hydrolysates showed a better antioxidant property compared to those of HC rats, which was accompanied with an increase in paraoxonase activity when compared to HC group. Originality/value Unlike PFPH which had almost no effect, FPs and EFPH could constitute a nutraceutical ingredient in cardiovascular disease management

    Metagenomic Analysis Indicates that Stressors Induce Production of Herpes-Like Viruses in Coral \u3cem\u3ePorites compressa\u3c/em\u3e

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    During the last several decades corals have been in decline and at least one-third of all coral species are now threatened by extinction. Coral disease has been a major contributor to this threat, but little is known about the responsible pathogens. To date most research has focused on bacterial and fungal diseases; however, viruses may also be important for coral health. Using a combination of empirical viral metagenomics and real-time PCR, we show that Porites compressa corals contain a suite of eukaryotic viruses, many related to the Herpesviridae. This coral-associated viral consortium was found to shift in response to abiotic stressors. In particular, when exposed to reduced pH, elevated nutrients, and thermal stress, the abundance of herpes-like viral sequences rapidly increased in 2 separate experiments. Herpes-like viral sequences were rarely detected in apparently healthy corals, but were abundant in a majority of stressed samples. In addition, surveys of the Nematostella and Hydra genomic projects demonstrate that even distantly related Cnidarians contain numerous herpes-like viral genes, likely as a result of latent or endogenous viral infection. These data support the hypotheses that corals experience viral infections, which are exacerbated by stress, and that herpes-like viruses are common in Cnidarians

    Direct and sequential radiative three-body reaction rates at low temperatures

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    We investigate the low-temperature reaction rates for radiative capture processes of three particles. We compare direct and sequential capture mechanisms and rates using realistic phenomenological parametrizations of the corresponding photodissociation cross sections.Energy conservation prohibits sequential capture for energies smaller than that of the intermediate two-body structure. A finite width or a finite temperature allows this capture mechanism. We study generic effects of positions and widths of two- and three-body resonances for very low temperatures. We focus on nuclear reactions relevant for astrophysics, and we illustrate with realistic estimates for the α\alpha-α\alpha-α\alpha and α\alpha-α\alpha-nn radiative capture processes. The direct capture mechanism leads to reaction rates which for temperatures smaller than 0.1 GK can be several orders of magnitude larger than those of the NACRE compilation.Comment: To be published in European Physical Journal

    Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

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    This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio

    Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

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    The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter

    Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

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    We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters

    Measurement of the inclusive isolated prompt photon cross-section in pp collisions at sqrt(s)= 7 TeV using 35 pb-1 of ATLAS data

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    A measurement of the differential cross-section for the inclusive production of isolated prompt photons in pp collisions at a center-of-mass energy sqrt(s) = 7 TeV is presented. The measurement covers the pseudorapidity ranges |eta|<1.37 and 1.52<=|eta|<2.37 in the transverse energy range 45<=E_T<400GeV. The results are based on an integrated luminosity of 35 pb-1, collected with the ATLAS detector at the LHC. The yields of the signal photons are measured using a data-driven technique, based on the observed distribution of the hadronic energy in a narrow cone around the photon candidate and the photon selection criteria. The results are compared with next-to-leading order perturbative QCD calculations and found to be in good agreement over four orders of magnitude in cross-section.Comment: 7 pages plus author list (18 pages total), 2 figures, 4 tables, final version published in Physics Letters
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