1,652 research outputs found

    The Costs of Biosecurity at the Farm Level: the Case of Finnish Broiler

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    In the European Union, the animal health and food safety strategy includes managing biosecurity along the entire production chain. Farm-level biosecurity provides the foundation for this. However, the farm-level costs of preventive biosecurity have rarely been assessed. Yet many risk management practices are in place constantly regardless of whether there is a disease outbreak or not. We contribute towards filling this information gap by studying the costs incurred in preventive biosecurity by the Finnish poultry farms. In a preliminary analysis, we find that the cost of biosecurity is some 3.55 cents per bird for broiler producers and 75.7 cents per bird for hatching egg producers. The results indicate that work-time devoted to biosecurity represents some 8% of total work time on broiler farms and about 5% on breeder farms.Biosecurity, on-farm costs, poultry, Livestock Production/Industries,

    Isotope effect on superconductivity in Josephson coupled stripes in underdoped cuprates

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    Inelastic neutron scattering data for YBaCuO as well as for LaSrCuO indicate incommensurate neutron scattering peaks with incommensuration δ(x)\delta(x) away from the (π,π)(\pi,\pi) point. Tc(x)T_c(x) can be replotted as a linear function of the incommensuration for these materials. This linear relation implies that the constant that relates these two quantities, one being the incommensuration (momentum) and another being Tc(x)T_c(x) (energy), has the dimension of velocity we denote vv^*: kBTc(x)=vδ(x)k_B T_c(x) = \hbar v^* \delta(x). We argue that this experimentally derived relation can be obtained in a simple model of Josephson coupled stripes. Within this framework we address the role of the O16O18O^{16} \to O^{18} isotope effect on the Tc(x)T_c(x). We assume that the incommensuration is set by the {\em doping} of the sample and is not sensitive to the oxygen isotope given the fixed doping. We find therefore that the only parameter that can change with O isotope substitution in the relation Tc(x)δ(x)T_c(x) \sim \delta(x) is the velocity vv^*. We predict an oxygen isotope effect on vv^* and expect it to be 5\simeq 5%.Comment: 4 pages latex file, 2 eps fig

    Universal Amplitude Ratios in the Ising Model in Three Dimensions

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    We use a high-precision Monte Carlo simulation to determine the universal specific-heat amplitude ratio A+/A- in the three-dimensional Ising model via the impact angle \phi of complex temperature zeros. We also measure the correlation-length critical exponent \nu from finite-size scaling, and the specific-heat exponent \alpha through hyperscaling. Extrapolations to the thermodynamic limit yield \phi = 59.2(1.0) degrees, A+/A- = 0.56(3), \nu = 0.63048(32) and \alpha = 0.1086(10). These results are compatible with some previous estimates from a variety of sources and rule out recently conjectured exact values.Comment: 17 pages, 5 figure

    Multivariable Christoffel-Darboux kernels and characteristic polynomials of random hermitian matrices

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    We study multivariable Christoffel-Darboux kernels, which may be viewed as reproducing kernels for antisymmetric orthogonal polynomials, and also as correlation functions for products of characteristic polynomials of random Hermitian matrices. Using their interpretation as reproducing kernels, we obtain simple proofs of Pfaffian and determinant formulas, as well as Schur polynomial expansions, for such kernels. In subsequent work, these results are applied in combinatorics (enumeration of marked shifted tableaux) and number theory (representation of integers as sums of squares)

    Identifying leverage points for strengthening adaptive capacity to climate change

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    Leverage points from systems research are increasingly important to understand how to support transformations towards sustainability, but few studies have considered leverage points in strengthening adaptive capacity to climate change. The existing literature mainly considers strengthening adaptive capacity as a steady and linear process. This article explores possibilities to fast track positive adaptive capacity trajectories of small-scale farmers in the Northern Region of Ghana. Leverage points were identified by triangulating data from semi-structured interviews with farmers (n=72), key informant interviews (n=7) and focus group discussions (FG1 n=17; FG2 n=20). The results present two ways to approach adaptation planning: 1) using four generic leverage points (gender equality, social learning, information and knowledge, and access to finance) or 2) combining the adaptive capacity and leverage point frameworks, thereby creating 15 associations. The generic points provide a set of topics as a starting point for policy and intervention planning activities, while the 15 associations support the identification of place-specific leverage points. Four benefits of using leverage points for adaptive capacity in adaptation planning were identified: guidance on where to intervene in a system, ability to deal with complex systems, inclusion of both causal and teleological decision-making, and a possibility to target deep, transformative change. © 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.Peer reviewe

    The Vertex-Face Correspondence and the Elliptic 6j-symbols

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    A new formula connecting the elliptic 6j6j-symbols and the fusion of the vertex-face intertwining vectors is given. This is based on the identification of the kk fusion intertwining vectors with the change of base matrix elements from Sklyanin's standard base to Rosengren's natural base in the space of even theta functions of order 2k2k. The new formula allows us to derive various properties of the elliptic 6j6j-symbols, such as the addition formula, the biorthogonality property, the fusion formula and the Yang-Baxter relation. We also discuss a connection with the Sklyanin algebra based on the factorised formula for the LL-operator.Comment: 23 page

    An (inverse) Pieri formula for Macdonald polynomials of type C

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    We give an explicit Pieri formula for Macdonald polynomials attached to the root system C_n (with equal multiplicities). By inversion we obtain an explicit expansion for two-row Macdonald polynomials of type C.Comment: 31 pages, LaTeX, to appear in Transformation Group

    Evaluation of shared genetic susceptibility loci between autoimmune diseases and schizophrenia based on genome-wide association studies.

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    BACKGROUND: Epidemiological studies have documented higher than expected comorbidity (or, in some cases, inverse comorbidity) between schizophrenia and several autoimmune disorders. It remains unknown whether this comorbidity reflects shared genetic susceptibility loci. AIMS: The present study aimed to investigate whether verified genome wide significant variants of autoimmune disorders confer risk of schizophrenia, which could suggest a common genetic basis. METHODS: Seven hundred and fourteen genome wide significant risk variants of 25 autoimmune disorders were extracted from the NHGRI GWAS catalogue and examined for association to schizophrenia in the Psychiatric Genomics Consortium schizophrenia GWAS samples (36,989 cases and 113,075 controls). RESULTS: Two independent loci at 4q24 and 6p21.32-33 originally identified from GWAS of autoimmune diseases were found genome wide associated with schizophrenia (1.7 × 10(-8 )≥( )p ≥ 4.0 × 10(-21)). While these observations confirm the existence of shared genetic susceptibility loci between schizophrenia and autoimmune diseases, the findings did not show a significant enrichment. CONCLUSION: The findings do not support a genetic overlap in common SNPs between autoimmune diseases and schizophrenia that in part could explain the observed comorbidity from epidemiological studies

    SOS model partition function and the elliptic weight functions

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    We generalize a recent observation [arXiv:math/0610433] that the partition function of the 6-vertex model with domain-wall boundary conditions can be obtained by computing the projections of the product of the total currents in the quantum affine algebra Uq(sl^2)U_{q}(\hat{\mathfrak{sl}}_{2}) in its current realization. A generalization is proved for the the elliptic current algebra [arXiv:q-alg/9703018,arXiv:q-alg/9601022]. The projections of the product of total currents are calculated explicitly and are represented as integral transforms of the product of the total currents. We prove that the kernel of this transform is proportional to the partition function of the SOS model with domain-wall boundary conditions.Comment: 21 pages, 5 figures, requires iopart packag
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