31,708 research outputs found

    U.S. Farm Policy and the WTO: How Do They Match Up?

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    The debate over a new farm bill has focused on how to spend an additional $73.5 billion in funding for the agricultural budget over ten years. The House of Representatives, the Senate Agriculture Committee, and Senators Cochran and Roberts (supported by the Bush Administration) have each proposed a structure for the next farm bill. A critical question becomes whether these proposals conflict with U.S. commitments to limit subsidies under the World Trade Organization (WTO) agreement. This paper explores this issue and concludes with a discussion of the future direction of U.S. farm subsidies and new WTO agreements.agricultural policy, domestic support, trade commitments, WTO, Agricultural and Food Policy, International Relations/Trade,

    The locality of the square-root method for improved staggered quarks

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    We study the effects of improvement on the locality of square-rooted staggered Dirac operators in lattice QCD simulations. We find the localisation lengths of the improved operators (FAT7TAD and ASQTAD) to be very similar to that of the one-link operator studied by Bunk et al., being at least the Compton wavelength of the lightest particle in the theory, even in the continuum limit. We conclude that improvement has no effect. We discuss the implications of this result for the locality of the nth-rooted fermion determinant used to reduce the number of sea quark flavours, and for possible staggered valence quark formulations

    U.S. Farm Policy and the World Trade Organization: How Do They Match Up?

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    The debate over a new farm bill has focused on how to spend an additional $73.5 billion in funding for the agricultural budget over 10 years. The House of Representatives, the Senate agriculture committee, and Senators Cochran and Roberts (supported by the Bush administration) have each proposed a structure for the next farm bill. A critical question becomes whether these proposals conflict with U.S. commitments to limit subsidies under the World Trade Organization (WTO) agreement. This paper explores this issue and concludes with a discussion of the future direction of U.S. farm subsidies and new WTO agreements.

    Observations of Cavitation on a Three-Dimensional Oscillating Hydrofoil

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    A test apparatus was designed and constructed to observe the effect of sinusoidal pitching oscillations on the cavitation of three-dimensional hydrofoils. The apparatus is capable of oscillating hydrofoils at a rate up to 50 Hz and provides for adjustments in oscillation amplitude and mean angle of attack. Observations of the effect of pitching oscillation on cavitation have been made for a NACA 64-309 (modified) hydrofoil operating at its designed mean angle of attack of 7 degrees with an oscillation amplitude of 2 degrees. Photographs illustrating the interaction between natural cavity shedding frequencies and the foil reduced frequency are included

    Monopole clusters in Abelian projected gauge theories

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    We show that the monopole currents which one obtains in the maximally Abelian gauge of SU(2) fall into two quite distinct classes (when the volume is large enough). In each field configuration there is precisely one cluster that permeates the whole lattice volume. It has a current density and a magnetic screening mass that scale and it produces the whole of the string tension. The remaining clusters have a number density that follows an approximate power law proportional to the inverse cube of l where l is the length of the monopole world line in lattice units. These clusters are localised in space-time with radii which vary as the square root of l. In terms of the radius r these `lumps' have a scale-invariant distribution proportional to (dr/r . 1/{r^4}). Moreover they appear not to contribute at all to the string tension. The fact that they are scale-invariant at small distances would seem to rule out an instanton origin.Comment: LaTeX, 31 pages, 11 PostScript figures. Typo in Table 2 correcte

    Effect of moisture on cadmium sulfide solar cells

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    Moisture effect on thin-film cadmium-sulfide solar cell

    Loss of redundant gene expression after polyploidization in plants

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    Based on chromosomal location data of genes encoding 28 biochemical systems in allohexaploid wheat,Triticum aestivum L. (genomes AABBDD), it is concluded that the proportions of systems controlled by triplicate, duplicate, and single loci are 57%, 25%, and 18% respectively

    Parasites Recovered From Overwintering Mimosa Webworm, \u3ci\u3eHomadaula Anisocentra\u3c/i\u3e (Lepidoptera: Plutellidae)

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    The mimosa webworm, Homadaula anisocentra, overwinters in the pupal stage. Two parasites, Parania geniculata and Elasmus albizziae, are associated with overwintering pupae or the immediate prepupal larvae. Combined parasitism during the winters of 1981-82,1982-83, and 1983-84 was 2.1,3.9, and 2.9%, respectively

    The Low-Lying Dirac Spectrum of Staggered Quarks

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    We investigate and clarify the role of topology and the issues surrounding the epsilon regime for staggered quarks. We study unimproved and improved staggered quark Dirac operators on quenched lattice QCD gluon backgrounds generated using a Symanzik-improved gluon action. For the improved Dirac operators we find a clear separation of the spectrum into would-be zero modes and others. The number of would-be zero modes depends on the topological charge as predicted by the continuum Index Theorem, and the expectation values of their chirality are large for the most improved actions (approx 0.7). The remaining modes have low chirality and show clear signs of clustering into quartets that become degenerate in the continuum limit. We demonstrate that the lattice spacing and volume dependence of the eigenvalues follow expectations. Furthermore, the non-zero modes follow the random matrix theory predictions for all topological charge sectors. The values of the chiral condensate extracted from fits to the theoretical distributions are consistent with each other, and with the results obtained from the total density of eigenvalues using the Banks-Casher relation. We conclude that staggered quarks respond correctly to QCD topology when both fermion and gauge actions are improved.Comment: 17 pages, a few typos corrected, part of one figure change

    The monopole mass in the three-dimensional Georgi-Glashow model

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    We study the three-dimensional Georgi-Glashow model to demonstrate how magnetic monopoles can be studied fully non-perturbatively in lattice Monte Carlo simulations, without any assumptions about the smoothness of the field configurations. We examine the apparent contradiction between the conjectured analytic connection of the `broken' and `symmetric' phases, and the interpretation of the mass (i.e., the free energy) of the fully quantised 't Hooft-Polyakov monopole as an order parameter to distinguish the phases. We use Monte Carlo simulations to measure the monopole free energy and its first derivative with respect to the scalar mass. On small volumes we compare this to semi-classical predictions for the monopole. On large volumes we show that the free energy is screened to zero, signalling the formation of a confining monopole condensate. This screening does not allow the monopole mass to be interpreted as an order parameter, resolving the paradox.Comment: 12 pages, 7 figures, uses revtex. Minor changes made to the text to match with the published version at http://link.aps.org/abstract/PRD/v65/e12500
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