211 research outputs found

    Growth Stimulating Products for Feedlot Heifers Fed High-Concentrate Diets of High-Moisture Corn

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    This experiment was one in a series to determine the response by fee dlot heifers to various growth promoting products . Products tested were diethylstilbestrol (DES), zeranol and melengestrol acetate (MGA) under conditions of high-concentrate diets with high-moisture grain and hay or haylage

    Adaptation of Feedlot Cattle to Urea and Antibacterial Compounds

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    A period of adaptation to urea during which feedlot performance is suppressed is frequently experienced when this product is added to rations of cattle not previously, or recently, fed it. This effect appears more evident with levels of urea used when it forms a major part of total protein in the ration. Urea and antibiotics in combination are common additions to protein supplements or mixed rations. At usual levels for continuous feeding of antibiotics and safe levels of urea for the dietary conditions, the combination appears satisfactory and to offer the beneficial effects from these compounds after a suitable period of urea adaptation. However, much less is known about the effects of high levels of antibacterial compounds and urea together during early stages in the feedlot with unadapted cattle. More research is needed to answer questions concerning levels of these compounds during early stages in the feedlot, especially with calves shipped at weaning or a few weeks thereafter. Other information needed includes the relative effects of adaptation to urea and antibacterial singularly and together after various times of arrival of the cattle at the feedlot. Effects of adding urea to furnish the major source of supplemental protein to a corn silage ration for calves at various times following arrival at the feedlot were investigated in this experiment. Urea additions were made to rations of calves fed with and without antibacterial compounds

    A unifying framework for seed sensitivity and its application to subset seeds

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    We propose a general approach to compute the seed sensitivity, that can be applied to different definitions of seeds. It treats separately three components of the seed sensitivity problem -- a set of target alignments, an associated probability distribution, and a seed model -- that are specified by distinct finite automata. The approach is then applied to a new concept of subset seeds for which we propose an efficient automaton construction. Experimental results confirm that sensitive subset seeds can be efficiently designed using our approach, and can then be used in similarity search producing better results than ordinary spaced seeds

    Burkhardt-Cottingham sum rule and forward spin polarizabilities in Heavy Baryon Chiral Perturbation Theory

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    We study spin-dependent sum rules for forward virtual Compton scattering(VVCS) off the nucleon in heavy baryon chiral perturbation theory at order O(p4)O(p^4). We show how these sum rules can be evaluated from low energy expansions (in the virtual photon energy) of the forward VVCS amplitudes. We study in particular the Burkhardt -Cottingham sum rule in HBChPT and higher terms in the low energy expansion, which can be related to the generalized forward spin polarizabilities of the nucleon. The dependence of these observables on the photon virtuality Q2Q^2 can be accessed, at small and intermediate Q2Q^2 values, from existing and forthcoming data at Jefferson Lab.Comment: 16 pages,4 fig

    Twist-2 Heavy Flavor Contributions to the Structure Function g2(x,Q2)g_2(x,Q^2)

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    The twist--2 heavy flavor contributions to the polarized structure function g2(x,Q2)g_2(x,Q^2) are calculated. We show that this part of g2(x,Q2)g_2(x,Q^2) is related to the heavy flavor contribution to g1(x,Q2)g_1(x,Q^2) by the Wandzura--Wilczek relation to all orders in the strong coupling constant. Numerical results are presented.Comment: 17 pages LATEX, 1 style files, 4 figure

    Statistical properties of the Burgers equation with Brownian initial velocity

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    We study the one-dimensional Burgers equation in the inviscid limit for Brownian initial velocity (i.e. the initial velocity is a two-sided Brownian motion that starts from the origin x=0). We obtain the one-point distribution of the velocity field in closed analytical form. In the limit where we are far from the origin, we also obtain the two-point and higher-order distributions. We show how they factorize and recover the statistical invariance through translations for the distributions of velocity increments and Lagrangian increments. We also derive the velocity structure functions and we recover the bifractality of the inverse Lagrangian map. Then, for the case where the initial density is uniform, we obtain the distribution of the density field and its nn-point correlations. In the same limit, we derive the nn-point distributions of the Lagrangian displacement field and the properties of shocks. We note that both the stable-clustering ansatz and the Press-Schechter mass function, that are widely used in the cosmological context, happen to be exact for this one-dimensional version of the adhesion model.Comment: 42 pages, published in J. Stat. Phy

    Wetting films on chemically heterogeneous substrates

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    Based on a microscopic density functional theory we investigate the morphology of thin liquidlike wetting films adsorbed on substrates endowed with well-defined chemical heterogeneities. As paradigmatic cases we focus on a single chemical step and on a single stripe. In view of applications in microfluidics the accuracy of guiding liquids by chemical microchannels is discussed. Finally we give a general prescription of how to investigate theoretically the wetting properties of substrates with arbitrary chemical structures.Comment: 56 pages, RevTeX, 20 Figure

    Physics Opportunities with the 12 GeV Upgrade at Jefferson Lab

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    This white paper summarizes the scientific opportunities for utilization of the upgraded 12 GeV Continuous Electron Beam Accelerator Facility (CEBAF) and associated experimental equipment at Jefferson Lab. It is based on the 52 proposals recommended for approval by the Jefferson Lab Program Advisory Committee.The upgraded facility will enable a new experimental program with substantial discovery potential to address important topics in nuclear, hadronic, and electroweak physics.Comment: 64 page

    Measurement of the Running of the Electromagnetic Coupling at Large Momentum-Transfer at LEP

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    The evolution of the electromagnetic coupling, alpha, in the momentum-transfer range 1800GeV^2 < -Q^2 < 21600GeV^2 is studied with about 40000 Bhabha-scattering events collected with the L3 detector at LEP at centre-of-mass energies 189-209GeV. The running of alpha is parametrised as: alpha(Q^2) = alpha_0/(1-C Delta alpha(Q^2)), where alpha_0=\alpha(Q^2=0) is the fine-structure constant and C=1 corresponds to the evolution expected in QED. A fit to the differential cross section of the e+e- ->e+e- process for scattering angles in the range |cos theta|<0.9 excludes the hypothesis of a constant value of alpha, C=0, and validates the QED prediction with the result: C = 1.05 +/- 0.07 +/- 0.14, where the first uncertainty is statistical and the second systematic
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