2,715 research outputs found

    Effects of various uterine treatments on calving-to-conception interval

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    Cows were given intrauterine infusions of enzymes, antibacterials, bacteria, or a combination of enzymes and antibacterials after calving to study basic changes in the post-partum uterus and effect on rebreeding. The group given nitrofurazone, an antibacterial compound, had the highest conception rate; however, calving-to-conception interval was lengthened. Combining proteolytic enzymes with the nitrofurazone gave an intercal to conception similar to that of control cows. Nitrofurazone caused this uterine lining to erode. Combining enzymes with nitrofurazone prevented some of the erosion. Innoculating the uterus with bacteria (Lactobacillus acidophilus) after calving did not affect the calving-to-conception interval

    Matrix Elements without Quark Masses on the Lattice

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    We introduce a new parameterization of four-fermion matrix elements which does not involve quark masses and thus allows a reduction of systematic uncertainties in physical amplitudes. As a result the apparent quadratic dependence of e'/e on m_s is removed. To simplify the matching between lattice and continuum renormalization schemes, we express our results in terms of Renormalization Group Invariant B-parameters which are renormalization-scheme and scale independent. As an application of our proposal, matrix elements of DeltaI=3/2 and SUSY DeltaF=2 (F=S,C,BF=S,C,B) four-fermion operators have been computed.Comment: LATTICE99(Matrix Elements), 3 pages, 1 figure, BUHEP-99-2

    Effective Field Theories

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    Effective field theories encode the predictions of a quantum field theory at low energy. The effective theory has a fairly low ultraviolet cutoff. As a result, loop corrections are small, at least if the effective action contains a term which is quadratic in the fields, and physical predictions can be read straight from the effective Lagrangean. Methods will be discussed how to compute an effective low energy action from a given fundamental action, either analytically or numerically, or by a combination of both methods. Basically,the idea is to integrate out the high frequency components of fields. This requires the choice of a "blockspin",i.e. the specification of a low frequency field as a function of the fundamental fields. These blockspins will be the fields of the effective field theory. The blockspin need not be a field of the same type as one of the fundamental fields, and it may be composite. Special features of blockspins in nonabelian gauge theories will be discussed in some detail. In analytical work and in multigrid updating schemes one needs interpolation kernels \A from coarse to fine grid in addition to the averaging kernels CC which determines the blockspin. A neural net strategy for finding optimal kernels is presented. Numerical methods are applicable to obtain actions of effective theories on lattices of finite volume. The constraint effective potential) is of particular interest. In a Higgs model it yields the free energy, considered as a function of a gauge covariant magnetization. Its shape determines the phase structure of the theory. Its loop expansion with and without gauge fields can be used to determine finite size corrections to numerical data.Comment: 45 pages, 9 figs., preprint DESY 92-070 (figs. 3-9 added in ps format

    Product Choice and the Importance of Aesthetic Design Given the Emotion‐laden Trade‐off between Sustainability and Functional Performance

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    This paper investigates the trade‐off decision that consumers face when choosing between a product that is perceived to be more sustainable (i.e., more socially and environmentally responsible) and another product that instead is perceived to offer superior functional performance. Prior research has demonstrated that consumers often believe that there is a trade‐off between sustainability and performance, and in some cases, this trade‐off may be real and not just perceived. The objectives of the current research are to understand the mediators and moderators of this trade‐off choice and to illustrate one specific way in which to use this understanding to promote the consumption of relatively more sustainable products despite a perceived performance trade‐off. Two separate studies were conducted. The first employed a student‐based sample, whereas the second employed a nationally representative online sample. In both studies, participants were presented with a choice between two consumer products. One product was depicted as having superior sustainability characteristics (and average functional performance), and the other product was depicted as having superior functional performance (and average sustainability characteristics). Participants were asked to imagine that they were leaning toward choosing one product over the other, and then rated the degree to which they were feeling a set of possible emotions. Following these ratings, participants chose one of the products. The results suggest that consumers presented with such a trade‐off will tend to choose the product with superior functional performance over the product with superior sustainability characteristics, due to feelings of distress, until a minimum threshold of functional performance is achieved. The current research also shows that choice given this trade‐off depends upon the degree to which consumers value sustainability that, in turn, is mediated by consumers’ feelings of confidence and guilt. Further, based on an understanding of the emotions mediating choice in this context, the authors demonstrate how the effective use of product aesthetic design can improve the relative choice likelihood of sustainable products. Specifically, the authors demonstrate that superior aesthetic design has a disproportionately positive effect on the choice likelihood of sustainability‐advantaged (versus performance‐advantaged) products due to the effect that superior aesthetic design has on overcoming the potential lack of confidence in sustainable products. These findings highlight the specific value of aesthetic product design in the context of marketing sustainable products and suggest that it is especially important for firms interested in marketing sustainable products to also develop market‐leading product aesthetic design capabilities

    Diffractive Higgs Production by AdS Pomeron Fusion

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    The double diffractive Higgs production at central rapidity is formulated in terms of the fusion of two AdS gravitons/Pomerons first introduced by Brower, Polchinski, Strassler and Tan in elastic scattering. Here we propose a simple self-consistent holographic framework capable of providing phenomenologically compelling estimates of diffractive cross sections at the LHC. As in the traditional weak coupling approach, we anticipate that several phenomenological parameters must be tested and calibrated through factorization for a self-consistent description of other diffractive process such as total cross sections, deep inelastic scattering and heavy quark production in the central region.Comment: 53 pages, 8 figure

    Measuring the Decorrelation Times of Fourier Modes in Simulations

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    We describe a method to study the rate at which modes decorrelate in numerical simulations. We study the XY model updated with the Metropolis and Wolff dynamics respectively and compute the rate at which each eigenvector of the dynamics decorrelates. Our method allows us to identify the decorrelation time for each mode separately. We find that the autocorrelation function of the various modes is markedly different for the `local' Metropolis compared to the `non-local' Wolff dynamics. Equipped with this new insight, it may be possible to devise highly efficient algorithms.Comment: 16 pp (LaTeX), PUPT-1378 , IASSNS-HEP-93/

    Halting indigenous biodiversity decline: ambiguity, equity, and outcomes in RMA assessment of significance

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    In New Zealand, assessment of ‘significance’ is undertaken to give effect to a legal requirement for local authorities to provide for protection of significant sites under the Resource Management Act (1991). The ambiguity of the statute enables different interests to define significance according to their goals: vested interests (developers), local authorities, and non-vested interests in pursuit of protection of environmental public goods may advance different definitions. We examine two sets of criteria used for assessment of significance for biological diversity under the Act. Criteria adapted from the 1980s Protected Natural Areas Programme are inadequate to achieve the maintenance of biological diversity if ranking is used to identify only highest priority sites. Norton and Roper-Lindsay (2004) propose a narrow definition of significance and criteria that identify only a few high-quality sites as significant. Both sets are likely to serve the interests of developers and local authorities, but place the penalty of uncertainty on non-vested interests seeking to maintain biological diversity, and are likely to exacerbate the decline of biological diversity and the loss of landscape-scale processes required for its persistence. When adopting criteria for assessment of significance, we suggest local authorities should consider whose interests are served by different criteria sets, and who will bear the penalty of uncertainty regarding biological diversity outcomes. They should also ask whether significance criteria are adequate, and sufficiently robust to the uncertainty inherent in the assessment of natural values, to halt the decline of indigenous biological diversity

    Chiral Condensate and Short-Time Evolution of QCD(1+1) on the Light-Cone

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    Chiral condensates in the trivial light-cone vacuum emerge if defined as short-time limits of fermion propagators. In gauge theories, the necessary inclusion of a gauge string in combination with the characteristic light-cone infrared singularities contain the relevant non-perturbative ingredients responsible for formation of the condensate, as demonstrated for the 't Hooft model.Comment: 4 pages, Revtex

    Universal correlators for multi-arc complex matrix models

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    The correlation functions of the multi-arc complex matrix model are shown to be universal for any finite number of arcs. The universality classes are characterized by the support of the eigenvalue density and are conjectured to fall into the same classes as the ones recently found for the Hermitian model. This is explicitly shown to be true for the case of two arcs, apart from the known result for one arc. The basic tool is the iterative solution of the loop equation for the complex matrix model with multiple arcs, which provides all multi-loop correlators up to an arbitrary genus. Explicit results for genus one are given for any number of arcs. The two-arc solution is investigated in detail, including the double-scaling limit. In addition universal expressions for the string susceptibility are given for both the complex and Hermitian model

    Regge behavior saves string theory from causality violations

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    Higher-derivative corrections to the Einstein-Hilbert action are present in bosonic string theory leading to the potential causality violations recently pointed out by Camanho et al. [1]. We analyze in detail this question by considering high-energy string-brane collisions at impact parameters b ≤ l s (the string-length parameter) with l s ≫ R p (the characteristic scale of the D p -brane geometry). If we keep only the contribution of the massless states causality is violated for a set of initial states whose polarization is suitably chosen with respect to the impact parameter vector. Such violations are instead neatly avoided when the full structure of string theory — and in particular its Regge behavior — is taken into account
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