540 research outputs found

    The Use Of Various Strains Of Rhizobium Tropici For Inoculation Of Snap Bean Cultivars With A Determinate Growth Pattern

    Get PDF
    The snap bean (Phaseolus vulgaris L.) is an economically important vegetable in Brazil. Bean plants can establish symbiotic associations with bacteria that fix atmospheric nitrogen. These associations show specificity of host plants to certain bacteria. Nitrogen fertilization constitutes a crop production cost, and the use of Rhizobium inoculation to supply nitrogen to crops may decrease the production costs. The aim of this study was to evaluate the effects of inoculation of three different snap bean cultivars with three Rhizobium tropici strains on agronomical performance of the plant. A completely randomized experimental design was used, with a 3 × 5 factorial scheme and four replicates per treatment. The factors tested were three snap bean cultivars (UEL 1, Alessa, and UEL 2), and five types of inoculation (uninoculated control, inoculation with SEMIA 4077, SEMIA 4080, SEMIA 4088, or with a mix of the three strains). The experiment was conducted in a greenhouse. Plant height, stem diameter, pod length, the number of pods per plant, and average weight and yield of commercial-grade pods, were determined. An analysis of variance was conducted using the F test, followed by Tukey's test (p < 0.05). Inoculation had a positive effect on all the parameters quantified. The beneficial effect was more pronounced in plants inoculated with the mix of Rhizobium strains.3763965397

    Caloric restriction is more efficient than physical exercise to protect from cisplatin nephrotoxicity via PPAR-alpha activation

    Get PDF
    The antineoplastic drug cisplatin promotes renal injury, which limits its use. Protocols that reduce renal cisplatin toxicity will allow higher doses to be used in cisplatin treatment. Here, we compare physical exercise and caloric restriction (CR) as protocols to reduce cisplatin renal injury in mice. Male C57BL/6 were divided into four groups: Control, cisplatin, exercise + cisplatin, and 30% CR + cisplatin. Animals were injected with a single dose of cisplatin (20 mg/kg i.p.) and sacrificed 96 h after injection. Quantitative real time PCR, histological analyses, immunohistochemistry, and biochemical measurements were performed to investigate renal injury, necrosis, apoptosis, and inflammatory mechanisms. Both protocols protected against cisplatin renal injury, but CR was more effective in reducing uraemia and renal necrosis. The CR + Cisplatin group exhibited reduced serum IL-1{beta} and TNF-{alpha} levels. No differences were noted in the renal mRNA expression of cytokines. Both interventions reduced apoptosis, but only the CR + Cisplatin group decreased TNFR2 protein expression. PPAR-{alpha} was activated in mice after CR. An antagonist of PPAR-{alpha} blocked the protective effect of CR. Both interventions attenuated the nephrotoxicity caused by cisplatin injection, but CR + Cisplatin showed a better response by modulating TNFR2. Moreover, part of the CR benefit depends on PPAR-{alpha} activation

    Reservoir cross-over in entanglement dynamics

    Full text link
    We study the effects of spontaneous emission on the entanglement dynamics of two qubits interacting with a common Lorentzian structured reservoir. We assume that the qubits are initially prepared in a Bell-like state. We focus on the strong coupling regime and study the entanglement dynamics for different regions of the spontaneous emission decay parameter. This investigation allows us to explore the cross-over between common and independent reservoirs in entanglement dynamics

    Anisotropy studies around the galactic centre at EeV energies with the Auger Observatory

    Get PDF
    Data from the Pierre Auger Observatory are analyzed to search for anisotropies near the direction of the Galactic Centre at EeV energies. The exposure of the surface array in this part of the sky is already significantly larger than that of the fore-runner experiments. Our results do not support previous findings of localized excesses in the AGASA and SUGAR data. We set an upper bound on a point-like flux of cosmic rays arriving from the Galactic Centre which excludes several scenarios predicting sources of EeV neutrons from Sagittarius AA. Also the events detected simultaneously by the surface and fluorescence detectors (the `hybrid' data set), which have better pointing accuracy but are less numerous than those of the surface array alone, do not show any significant localized excess from this direction.Comment: Matches published versio

    Multiwavelength studies of MHD waves in the solar chromosphere: An overview of recent results

    Get PDF
    The chromosphere is a thin layer of the solar atmosphere that bridges the relatively cool photosphere and the intensely heated transition region and corona. Compressible and incompressible waves propagating through the chromosphere can supply significant amounts of energy to the interface region and corona. In recent years an abundance of high-resolution observations from state-of-the-art facilities have provided new and exciting ways of disentangling the characteristics of oscillatory phenomena propagating through the dynamic chromosphere. Coupled with rapid advancements in magnetohydrodynamic wave theory, we are now in an ideal position to thoroughly investigate the role waves play in supplying energy to sustain chromospheric and coronal heating. Here, we review the recent progress made in characterising, categorising and interpreting oscillations manifesting in the solar chromosphere, with an impetus placed on their intrinsic energetics.Comment: 48 pages, 25 figures, accepted into Space Science Review

    Atmospheric effects on extensive air showers observed with the Surface Detector of the Pierre Auger Observatory

    Get PDF
    Atmospheric parameters, such as pressure (P), temperature (T) and density, affect the development of extensive air showers initiated by energetic cosmic rays. We have studied the impact of atmospheric variations on extensive air showers by means of the surface detector of the Pierre Auger Observatory. The rate of events shows a ~10% seasonal modulation and ~2% diurnal one. We find that the observed behaviour is explained by a model including the effects associated with the variations of pressure and density. The former affects the longitudinal development of air showers while the latter influences the Moliere radius and hence the lateral distribution of the shower particles. The model is validated with full simulations of extensive air showers using atmospheric profiles measured at the site of the Pierre Auger Observatory.Comment: 24 pages, 9 figures, accepted for publication in Astroparticle Physic

    Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter

    Get PDF
    Data collected by the Pierre Auger Observatory through 31 August 2007 showed evidence for anisotropy in the arrival directions of cosmic rays above the Greisen-Zatsepin-Kuz'min energy threshold, \nobreak{6×10196\times 10^{19}eV}. The anisotropy was measured by the fraction of arrival directions that are less than 3.13.1^\circ from the position of an active galactic nucleus within 75 Mpc (using the V\'eron-Cetty and V\'eron 12th12^{\rm th} catalog). An updated measurement of this fraction is reported here using the arrival directions of cosmic rays recorded above the same energy threshold through 31 December 2009. The number of arrival directions has increased from 27 to 69, allowing a more precise measurement. The correlating fraction is (386+7)(38^{+7}_{-6})%, compared with 2121% expected for isotropic cosmic rays. This is down from the early estimate of (6913+11)(69^{+11}_{-13})%. The enlarged set of arrival directions is examined also in relation to other populations of nearby extragalactic objects: galaxies in the 2 Microns All Sky Survey and active galactic nuclei detected in hard X-rays by the Swift Burst Alert Telescope. A celestial region around the position of the radiogalaxy Cen A has the largest excess of arrival directions relative to isotropic expectations. The 2-point autocorrelation function is shown for the enlarged set of arrival directions and compared to the isotropic expectation.Comment: Accepted for publication in Astroparticle Physics on 31 August 201
    corecore