485 research outputs found

    A Simple Method for Estimating Alfalfa Fiber Content in the Field

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    Predictive equations for alfalfa (Medicago sativa L.) quality (PEAQ) based on length of the longest stem and maturity stage of the most mature stem in a sample were developed and validated for estimating neutral detergent fiber (NDF) and acid detergent fiber (ADF) concentrations in alfalfa. The objective of this research was to validate PEAQ with a simplified maturity scale when estimating fiber content. Alfalfa samples varying in height and maturity were collected throughout the growing season from fields across six states in USA. Observed NDF and ADF values (determined via wet chemistry) were regressed on estimated values. The estimated values were calculated with PEAQ using the Kalu and Fick maturity scale (stages 2 to 6) and using a modified 3-stage scale consisting of vegetative stage (Kalu and Fick stage 2.0), bud stage (stage 3.5, i.e. averaged Kalu and Fick bud stages 3 and 4), and flower stage (stage 5.5, i.e. averaged Kalu and Fick flower stages 5 and 6). Regression equations for NDF and ADF were slightly biased (b 1.0 and/or y-intercept 0) for two of the three datasets regardless of the staging scale used. Prediction errors were similar regardless of the staging scale, ranging from 16.8 to 25.4 g kg-1 for NDF and 14.3 to 19.3 g kg-1 for ADF. We conclude that the 3-stage maturity scale can be used effectively in these equations for estimating alfalfa fiber content based on a combination of stem length and maturity

    Impact of Management on Endophyte Free and Endophyte Infected Tall Fescue Cultivars in Ohio

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    Ten cultivars of tall fescue (Festuca arundinacea, Schreb.) and one cultivar of orchardgrass (Dactylis glomerata L.) were part of a study to determine changes in endophyte levels of fescue under two different styles of forage management: intensive and extensive. Included in the study were two endophyte infected-cultivars of tall fescue to compare interactions with endophyte free and infected cultivars. After three years, the results demonstrate that under high levels of management and non-endophyte infected crops prior to seeding, introduction of the endophyte can be reduced or delayed. Under lower levels of management and a smother crop into endophyte infected fescue prior to seeding, high yielding endophyte free cultivars maintain the lowest percent of re-infection (25.0- 32.1% infected)

    Forage Nutritive Value Changes in a Stratified Canopy of a Mixed Cool-Season Grass Sward Affected by Season

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    The seasonal pattern of herbage growth rate is an important determinant on forage system productivity. Pasture stocking rates and supplemental feed requirements are influenced by the dynamic balance between forage growth and the amount of herbage available. There is limited in-formation regarding vertical distribution patterns (layers within the sward) in nutritive value in cool-season grasses, especially for vegetative herbage (Burner and Belesky 2004). More complete information could support decisions regarding cutting schedules, residual mass and heights to meet nutritional value targets, and timing of pasture allocation. The objective of this study was to characterize the vertical distribution of nutritive value components within a grass sward and the relationship between days past clipping over time on NDF and NDFD. This information was then used to determine the effect that forage canopy removal will have on the nutritive value of the remained forage

    Species Richness Affects Grassland Yield and Yield Stability Across Seasons, Sites and Years

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    The benefits of biodiversity (specifically species richness) are proposed to include both greater yield and greater stability of yield in a variable environment (Sanderson et al., 2004). Experimental evidence showing yield benefits is inconsistent (White et al., 2004). There is relatively little experimental data showing the effects of species richness on yield stability. The objective of this study was to measure the yield from mixtures with up to 12 species, and to measure the variability of yield between 2 sites, between spring and summer, and in 2 successive years

    Qudits of composite dimension, mutually unbiased bases and projective ring geometry

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    The d2d^2 Pauli operators attached to a composite qudit in dimension dd may be mapped to the vectors of the symplectic module Zd2\mathcal{Z}_d^{2} (Zd\mathcal{Z}_d the modular ring). As a result, perpendicular vectors correspond to commuting operators, a free cyclic submodule to a maximal commuting set, and disjoint such sets to mutually unbiased bases. For dimensions d=6, 10, 15, 12d=6,~10,~15,~12, and 18, the fine structure and the incidence between maximal commuting sets is found to reproduce the projective line over the rings Z6\mathcal{Z}_{6}, Z10\mathcal{Z}_{10}, Z15\mathcal{Z}_{15}, Z6×F4\mathcal{Z}_6 \times \mathbf{F}_4 and Z6×Z3\mathcal{Z}_6 \times \mathcal{Z}_3, respectively.Comment: 10 pages (Fast Track communication). Journal of Physics A Mathematical and Theoretical (2008) accepte

    New Exclusion Limits for the Search of Scalar and Pseudoscalar Axion-Like Particles from "Light Shining Through a Wall"

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    Physics beyond the Standard Model predicts the possible existence of new particles that can be searched at the low energy frontier in the sub-eV range. The OSQAR photon regeneration experiment looks for "Light Shining through a Wall" from the quantum oscillation of optical photons into "Weakly Interacting Sub-eV Particles", such as axion or Axion-Like Particles (ALPs), in a 9 T transverse magnetic field over the unprecedented length of 2×14.32 \times 14.3 m. In 2014, this experiment has been run with an outstanding sensitivity, using an 18.5 W continuous wave laser emitting in the green at the single wavelength of 532 nm. No regenerated photons have been detected after the wall, pushing the limits for the existence of axions and ALPs down to an unprecedented level for such a type of laboratory experiment. The di-photon couplings of possible pseudo-scalar and scalar ALPs can be constrained in the nearly massless limit to be less than 3.51083.5\cdot 10^{-8} GeV1^{-1} and 3.21083.2\cdot 10^{-8} GeV1^{-1}, respectively, at 95% Confidence Level.Comment: 6 pages, 6 figure

    Scedosporium and Pseudallescheria low molecular weight metabolites revealed by database search

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    The potential of mMass software search tool with new compound libraries was demonstrated on metabolomics of Scedosporium prolificans, S. apiospermum and Pseudallescheria boydii sensu stricto. Cyclic peptides pseudacyclins, small molecular weight tyroscherin analogues and various lipids were annotated by open source mass spectometry tool utilising accurate matrix-assisted laser desorption/ionisation mass spectral data of intact fungal spores. Electrospray ionisation combined with tandem mass spectrometry was used for monohexosylceramide characterisation in fungal extracts

    Search for weakly interacting sub-eV particles with the OSQAR laser-based experiment: results and perspectives

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    Recent theoretical and experimental studies highlight the possibility of new fundamental particle physics beyond the Standard Model that can be probed by sub-eV energy experiments. The OSQAR photon regeneration experiment looks for "Light Shining through a Wall" (LSW) from the quantum oscillation of optical photons into "Weakly Interacting Sub-eV Particles" (WISPs), like axion or axion-like particles (ALPs), in a 9 T transverse magnetic field over the unprecedented length of 2×14.32 \times 14.3 m. No excess of events has been detected over the background. The di-photon couplings of possible new light scalar and pseudo-scalar particles can be constrained in the massless limit to be less than 8.0×1088.0\times10^{-8} GeV1^{-1}. These results are very close to the most stringent laboratory constraints obtained for the coupling of ALPs to two photons. Plans for further improving the sensitivity of the OSQAR experiment are presented.Comment: 7 pages, 7 figure
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