2,445 research outputs found

    Research Notes: Evaluation of some soybean isolines in irrigation culture

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    About 9% of the total soybean acreage and about 50% of the total corn acreage in Nebraska was irrigated at least once during the growing season in 1975. The 1975 state averages for irrigated soybeans and irrigated corn were 2220 and 7605 kg/ha respectively. Obviously, this yield differential (in relation to the price and production cost differentials) accounts for the reason most farmers utilize their irrigated acreage for corn rather than soybeans

    Photon-Photon Entanglement with a Single Trapped Atom

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    An experiment is performed where a single rubidium atom trapped within a high-finesse optical cavity emits two independently triggered entangled photons. The entanglement is mediated by the atom and is characterized both by a Bell inequality violation of S=2.5, as well as full quantum-state tomography, resulting in a fidelity exceeding F=90%. The combination of cavity-QED and trapped atom techniques makes our protocol inherently deterministic - an essential step for the generation of scalable entanglement between the nodes of a distributed quantum network.Comment: 5 pages, 4 figure

    Detecting structural variances of Co_3O_4 catalysts by controlling beam-induced sample alterations in the vacuum of a transmission electron microscope

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    This article summarizes core aspects of beam-sample interactions in research that aims at exploiting the ability to detect single atoms at atomic resolution by mid-voltage transmission electron microscopy. Investigating the atomic structure of catalytic Co_3O_4 nanocrystals underscores how indispensable it is to rigorously control electron dose rates and total doses to understand native material properties on this scale. We apply in-line holography with variable dose rates to achieve this goal. Genuine object structures can be maintained if dose rates below ~100 e/Å^2s are used and the contrast required for detection of single atoms is generated by capturing large image series. Threshold doses for the detection of single atoms are estimated. An increase of electron dose rates and total doses to common values for high resolution imaging of solids stimulates object excitations that restructure surfaces, interfaces, and defects and cause grain reorientation or growth. We observe a variety of previously unknown atom configurations in surface proximity of the Co_3O_4 spinel structure. These are hidden behind broadened diffraction patterns in reciprocal space but become visible in real space by solving the phase problem. An exposure of the Co_3O_4 spinel structure to water vapor or other gases induces drastic structure alterations that can be captured in this manner

    Gut microbiota alteration in adolescent anorexia nervosa does not normalize with short-term weight restoration

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    Objective: Gut microbiota are linked to metabolic function, body weight regulation, and brain and behavioral changes. Alteration of gut microbiota is repeatedly demon- strated in adults with anorexia nervosa (AN) and transplantation of stool from adult patients with AN reduces weight gain, food consumption and food efficiency in germ-free mice. No similar data are available for adolescents, who might differ from adults due to their shorter duration of illness. Method: Nineteen female adolescent patients with AN at admission and after short-term weight recovery were included in a longitudinal study and compared to 20 healthy controls (HC). DNA was extracted from stool samples and subjected to 16S rRNA gene sequencing and analysis. Group comparisons, indicator genera and simper analysis were applied. Taxon abundances at admission was used to predict inpatient treatment duration. Results: Alpha diversity is increased in patients with AN after short-term weight recov- ery, while beta diversity shows clear group differences with HC before and after weight gain. A reduction in Romboutsia and taxa belonging to Enterobacteriaceae at both timepoints and an increase in taxa belonging to Lachnospiraceae at discharge are most indicative of patients. Lachnospiraceae abundance at admission helped to predict shorter inpatient treatment duration. Discussion: This pilot study provides first evidence of gut microbiota alterations in adolescent patients with AN that do not normalize with weight gain. If verified in larger studies, the predictive power of taxa belonging to Lachnospiraceae for clinical outcome could complement known predictors at admission, inform clinicians and serve as a target for nutritional interventions

    Semi-Hard Scattering Unraveled from Collective Dynamics by Two-Pion Azimuthal Correlations in 158 A GeV/c Pb + Au Collisions

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    Elliptic flow and two-particle azimuthal correlations of charged hadrons and high-pTp_T pions (pT>p_T> 1 GeV/cc) have been measured close to mid-rapidity in 158A GeV/cc Pb+Au collisions by the CERES experiment. Elliptic flow (v2v_2) rises linearly with pTp_T to a value of about 10% at 2 GeV/cc. Beyond pTp_T\approx 1.5 GeV/cc, the slope decreases considerably, possibly indicating a saturation of v2v_2 at high pTp_T. Two-pion azimuthal anisotropies for pT>p_T> 1.2 GeV/cc exceed the elliptic flow values by about 60% in mid-central collisions. These non-flow contributions are attributed to near-side and back-to-back jet-like correlations, the latter exhibiting centrality dependent broadening.Comment: Submitted to Phys. Rev. Letters, 4 pages, 5 figure

    Study of dimuon production in Indium-Indium collisions with the NA60 experiment

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    The NA60 experiment at the CERN-SPS is devoted to the study of dimuon production in heavy-ion and proton-nucleus collisions. We present preliminary results from the analysis of Indium-Indium collisions at 158 GeV per nucleon. The topics covered are low mass vector meson production, J/psi production and suppression, and the feasibility of the open charm measurement from the dimuon continuum in the mass range below the J/psi peak.Comment: Contribution at XXXXth Rencontres de Moriond, "QCD and High Energy Hadronic Interactions

    Fast Excitation and Photon Emission of a Single-Atom-Cavity System

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    We report on the fast excitation of a single atom coupled to an optical cavity using laser pulses that are much shorter than all other relevant processes. The cavity frequency constitutes a control parameter that allows the creation of single photons in a superposition of two tunable frequencies. Each photon emitted from the cavity thus exhibits a pronounced amplitude modulation determined by the oscillatory energy exchange between the atom and the cavity. Our technique constitutes a versatile tool for future quantum networking experiments.Comment: 4 pages, 5 figure

    NA60 results on thermal dimuons

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    The NA60 experiment at the CERN SPS has measured muon pairs with unprecedented precision in 158A GeV In-In collisions. A strong excess of pairs above the known sources is observed in the whole mass region 0.2<M<2.6 GeV. The mass spectrum for M<1 GeV is consistent with a dominant contribution from pi+pi- -> rho -> mu+mu- annihilation. The associated rho spectral function shows a strong broadening, but essentially no shift in mass. For M>1 GeV, the excess is found to be prompt, not due to enhanced charm production, with pronounced differences to Drell-Yan pairs. The slope parameter Teff associated with the transverse momentum spectra rises with mass up to the rho, followed by a sudden decline above. The rise for M<1 GeV is consistent with radial flow of a hadronic emission source. The seeming absence of significant flow for M>1 GeV and its relation to parton-hadron duality is discussed in detail, suggesting a dominantly partonic emission source in this region. A comparison of the data to the present status of theoretical modeling is also contained. The accumulated empirical evidence, including also a Planck-like shape of the mass spectra at low pT and the lack of polarization, is consistent with a global interpretation of the excess dimuons as thermal radiation. We conclude with first results on omega in-medium effects.Comment: 10 pages, 12 figures, submitted to Eur. Phys. J.
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