5,928 research outputs found

    The Use of Methanol-Grown Yeast LI-70 in Feeds for Broilers

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    Abstract In 60-day feeding trials, broilers were fed commercial diets in which different amounts of methanol-grown yeast LI-70 replaced fish and soybean meal. In the first trial, all-mash diets containing up to 15% yeast produced growth rates and efficiencies of feed conversion almost equal to those of the soybean meal control and slightly below those of the fish meal control. In the second trial, pelleted diets containing up to 25% yeast were used. For yeast levels up to 15%, growth rates were faster than for the soybean meal control and slightly slower than for the fish meal control. Diets with more than 15% yeast lacked selenium. Diets containing 25% yeast as the sole source of protein but supplemented with .3 ppm selenium produced growth rates and efficiencies of feed conversion equal to those of the controls

    Test with cosmic rays of the GEM chambers for the LHCb muon system produced in Cagliari

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    The inner region of the first LHCb muon station will be equipped with twelve Gas Electron Multiplier chambers. The seven chambers produced in Cagliari were studied for several days each using cosmic rays. We measured the efficiency, timing resolution, and uniformity, cluster-size and out-of-time multiplicity. We find all seven chambers perform well

    Are geometric morphometric analyses replicable? Evaluating landmark measurement error and its impact on extant and fossil Microtus classification.

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    Geometric morphometric analyses are frequently employed to quantify biological shape and shape variation. Despite the popularity of this technique, quantification of measurement error in geometric morphometric datasets and its impact on statistical results is seldom assessed in the literature. Here, we evaluate error on 2D landmark coordinate configurations of the lower first molar of five North American Microtus (vole) species. We acquired data from the same specimens several times to quantify error from four data acquisition sources: specimen presentation, imaging devices, interobserver variation, and intraobserver variation. We then evaluated the impact of those errors on linear discriminant analysis-based classifications of the five species using recent specimens of known species affinity and fossil specimens of unknown species affinity. Results indicate that data acquisition error can be substantial, sometimes explaining >30% of the total variation among datasets. Comparisons of datasets digitized by different individuals exhibit the greatest discrepancies in landmark precision, and comparison of datasets photographed from different presentation angles yields the greatest discrepancies in species classification results. All error sources impact statistical classification to some extent. For example, no two landmark dataset replicates exhibit the same predicted group memberships of recent or fossil specimens. Our findings emphasize the need to mitigate error as much as possible during geometric morphometric data collection. Though the impact of measurement error on statistical fidelity is likely analysis-specific, we recommend that all geometric morphometric studies standardize specimen imaging equipment, specimen presentations (if analyses are 2D), and landmark digitizers to reduce error and subsequent analytical misinterpretations

    Hadron detection with a dual-readout fiber calorimeter

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    In this paper, we describe measurements of the response functions of a fiber-based dual- readout calorimeter for pions, protons and multiparticle "jets" with energies in the range from 10 to 180 GeV. The calorimeter uses lead as absorber material and has a total mass of 1350 kg. It is complemented by leakage counters made of scintillating plastic, with a total mass of 500 kg. The effects of these leakage counters on the calorimeter performance are studied as well. In a separate section, we investigate and compare different methods to measure the energy resolution of a calorimeter. Using only the signals provided by the calorimeter, we demonstrate that our dual-readout calorimeter, calibrated with electrons, is able to reconstruct the energy of proton and pion beam particles to within a few percent at all energies. The fractional widths of the signal distributions for these particles (sigma/E) scale with the beam energy as 30%/sqrt(E), without any additional contributing terms

    Internal rotation of red giants by asteroseismology

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    We present an asteroseismic approach to study the dynamics of the stellar interior in red-giant stars by asteroseismic inversion of the splittings induced by the stellar rotation on the oscillation frequencies. We show preliminary results obtained for the red giant KIC4448777 observed by the space mission Kepler.Comment: 3 pages, 4 figures, the 40th Liege International Astrophysical Colloquium Liac40, 'Ageing low mass stars: from red giants to white dwarfs', to be published on EPJ Web of Conference

    Internal rotation of the red-giant star KIC 4448777 by means of asteroseismic inversion

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    In this paper we study the dynamics of the stellar interior of the early red-giant star KIC 4448777 by asteroseismic inversion of 14 splittings of the dipole mixed modes obtained from {\it Kepler} observations. In order to overcome the complexity of the oscillation pattern typical of red-giant stars, we present a procedure which involves a combination of different methods to extract the rotational splittings from the power spectrum. We find not only that the core rotates faster than the surface, confirming previous inversion results generated for other red giants (Deheuvels et al. 2012,2014), but we also estimate the variation of the angular velocity within the helium core with a spatial resolution of Δr=0.001R\Delta r=0.001R and verify the hypothesis of a sharp discontinuity in the inner stellar rotation (Deheuvels et al. 2014). The results show that the entire core rotates rigidly with an angular velocity of about ⟚Ωc/2π⟩=748±18\langle\Omega_c/2\pi\rangle=748\pm18~nHz and provide evidence for an angular velocity decrease through a region between the helium core and part of the hydrogen burning shell; however we do not succeed to characterize the rotational slope, due to the intrinsic limits of the applied techniques. The angular velocity, from the edge of the core and through the hydrogen burning shell, appears to decrease with increasing distance from the center, reaching an average value in the convective envelope of ⟚Ωs/2π⟩=68±22\langle\Omega_s/2\pi\rangle=68\pm22~nHz. Hence, the core in KIC~4448777 is rotating from a minimum of 8 to a maximum of 17 times faster than the envelope. We conclude that a set of data which includes only dipolar modes is sufficient to infer quite accurately the rotation of a red giant not only in the dense core but also, with a lower level of confidence, in part of the radiative region and in the convective envelope.Comment: accepted for publication on Ap

    Dual-readout Calorimetry

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    The RD52 Project at CERN is a pure instrumentation experiment whose goal is to understand the fundamental limitations to hadronic energy resolution, and other aspects of energy measurement, in high energy calorimeters. We have found that dual-readout calorimetry provides heretofore unprecedented information event-by-event for energy resolution, linearity of response, ease and robustness of calibration, fidelity of data, and particle identification, including energy lost to binding energy in nuclear break-up. We believe that hadronic energy resolutions of {\sigma}/E ≈\approx 1 - 2% are within reach for dual-readout calorimeters, enabling for the first time comparable measurement preci- sions on electrons, photons, muons, and quarks (jets). We briefly describe our current progress and near-term future plans. Complete information on all aspects of our work is available at the RD52 website http://highenergy.phys.ttu.edu/dream/.Comment: 10 pages, 10 figures, Snowmass White pape

    Nested interactions between chemosynthetic lucinid bivalves and seagrass promote ecosystem functioning in contaminated sediments

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    In seagrass sediments, lucinid bivalves and their chemoautotrophic bacterial symbionts consume H2S, relying indirectly on the plant productivity for the presence of the reduced chemical. Additionally, the role of lucinid bivalves in N provisioning to the plant (through N2 fixation by the symbionts) was hypothesized. Thus, lucinids may contribute to sediment detoxification and plant fitness. Seagrasses are subject to ever-increasing human pressure in coastal environments. Here, disentangling nested interactions between chemosynthetic lucinid bivalves and seagrass exposed to pollution may help to understand seagrass ecosystem dynamics and to develop successful seagrass restoration programs that consider the roles of animal-microbe symbioses. We evaluated the capacity of lucinid bivalves (Loripes orbiculatus) to promote nutrient cycling and seagrass (Cymodocea nodosa) growth during a 6-week mesocosm experiment. A fully crossed design was used to test for the effect of sediment contamination (metals, nutrients, and hydrocarbons) on plant and bivalve (alone or interacting) fitness, assessed by mortality, growth, and photosynthetic efficiency, and for the effect of their nested interaction on sediment biogeochemistry. Plants performed better in the contaminated sediment, where a larger pool of dissolved nitrogen combined with the presence of other trace elements allowed for an improved photosynthetic efficiency. In fact, pore water nitrogen accumulated during the experiment in the controls, while it was consumed in the contaminated sediment. This trend was accentuated when lucinids were present. Concurrently, the interaction between clams and plants benefitted both organisms and promoted plant growth irrespective of the sediment type. In particular, the interaction with lucinid clams resulted in higher aboveground biomass of C. nodosa in terms of leaf growth, leaf surface, and leaf biomass. Our results consolidate the notion that nested interactions involving animal-microbe associations promote ecosystem functioning, and potentially help designing unconventional seagrass restoration strategies that exploit chemosynthetic symbioses.VersiĂłn del edito

    Endoparasite infections of the european hedgehog (Erinaceus europaeus) in central Italy

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    The European hedgehog is a synanthropic mammal, widely distributed in Europe. This species usually inhabits the edges of deciduous or mixed woods, but it is also very common in private gardens and public parks. Despite its popularity and frequency of contacts both with humans and with wild and domestic animals, few studies have examined the endoparasitic fauna of the hedgehog in Italy. In the present study, endoparasites of naturally deceased hedgehogs (n = 40) from central Italy (Latium and Tuscany regions) were investigated, along with concurrent gross and histopathological lesions. The most prevalent identified endoparasites were Crenosoma striatum (45%), Capillaria erinacei (42.5%) and Brachylaemus erinacei (22.5%), in accordance with previous reports from hedgehogs in southern Italy. In few subjects, Physaloptera clausa, Acanthocephalans and Cystoisospora rastegaeivae coccidia were also identified. The infection by the lungworm C. striatum was found to be significantly associated (p < 0.01) with bronchial hyperplasia and peribronchiolitis upon histopathological examination. Awareness of the most common parasitic infections in the hedgehog and of their effects on the health of these animals is extremely important, especially in wildlife rescue centers, where European hedgehog represents the most frequently hospitalized mammal species

    Performance of the Muon Identification at LHCb

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    The performance of the muon identification in LHCb is extracted from data using muons and hadrons produced in J/\psi->\mu\mu, \Lambda->p\pi and D^{\star}->\pi D0(K\pi) decays. The muon identification procedure is based on the pattern of hits in the muon chambers. A momentum dependent binary requirement is used to reduce the probability of hadrons to be misidentified as muons to the level of 1%, keeping the muon efficiency in the range of 95-98%. As further refinement, a likelihood is built for the muon and non-muon hypotheses. Adding a requirement on this likelihood that provides a total muon efficiency at the level of 93%, the hadron misidentification rates are below 0.6%.Comment: 17 pages, 10 figure
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