13,250 research outputs found

    Windtunnel and field observations of western spruce budworm responses to pheromone-baited traps

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    Five trap designs, the Pherocon 1CP, a triangular trap, dome trap, double cone trap and Kendall trap were evaluated for capturing the western spruce budworm, <i>Choristoneura occidentalis</i> Freeman, both in a laboratory-based windtunnel and in an infested stand. Neutral density smoke tests showed the effects of orientation to wind on plume formation as well as highlighting plume structure around larger traps. Moth capture rates in the windtunnel did not always correlate with capture rates under field conditions

    Infrared images of merging galaxies

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    Infrared imaging of interacting galaxies is especially interesting because their optical appearance is often so chaotic due to extinction by dust and emission from star formation regions, that it is impossible to locate the nuclei or determine the true stellar distribution. However, at near-infrared wavelengths extinction is considerably reduced, and most of the flux from galaxies originates from red giant stars that comprise the dominant stellar component by mass. Thus near infrared images offer the opportunity to study directly components of galactic structure which are otherwise inaccessible. Such images may ultimately provide the framework in which to understand the activity taking place in many of the mergers with high Infrared Astronomy Satellite (IRAS) luminosities. Infrared images have been useful in identifying double structures in the nuclei of interacting galaxies which have not even been hinted at by optical observations. A striking example of this is given by the K images of Arp 220. Graham et al. (1990) have used high resolution imaging to show that it has a double nucleus coincident with the radio sources in the middle of the dust lane. The results suggest that caution should be applied in the identification of optical bright spots as multiple nuclei in the absence of other evidence. They also illustrate the advantages of using infrared imaging to study the underlying structure in merging galaxies. The authors have begun a program to take near infrared images of galaxies which are believed to be mergers of disk galaxies because they have tidal tails and filaments. In many of these the merger is thought to have induced exceptionally luminous infrared emission (cf. Joseph and Wright 1985, Sanders et al. 1988). Although the optical images of the galaxies show spectacular dust lanes and filaments, the K images all have a very smooth distribution of light with an apparently single nucleus

    Plant viruses.

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    Clover viruses, 82ES38, 82AL47, 82MA19, 82BR19, 82BY29; 82BU5, 82HA9. Lupin virus, diseases. Barley yellow dwarf virus, 82AL46, 82AL51, 82B10, 82BA33, 82BR16, 82BR18, 82C29, 82E27, 82ES37, 82ES40, 82JE19, 82JE20, 82KA33, 82KA34, 82ABI3, 82MA18, 82MN22, 82MT34, 82NA32, 82WH28,82B8, 82MN17, 82E24, 82MT30, 82E25, 82MN18, 82MT31, 82B9, 82ABI2, 82BA31, 82C26, 82JE17, 82WH27, 82AL45, 82BR17, 82ES39, 82MA1, 82MA117, 82MT33

    1981 Plant viruses

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    1, Clover viruses - 81HA6, 81MA9, 81BR14, 81BY12, 81BH5, 81AL38, 81ES39 OBJECTIVES: To determine the extent of the \u27Dinninup virus\u27 problem (sub. clover mottle). To further assess the incidence of red leaf virus to determine the incidence of bean yellow mosaic virus. To note the incidence of sub. clover stunt virus. A. BYDV: Survey of incidence - 81BU1, 81BU2, 81BR11, 81BR12, 81MA6, 81MA7, 81AL31, 81AL32, 81JE14, 81JE15, 81KA21, 81KA22, 81NA28, 81N031, 81ES38, 81E26. 2. Barley yellow dwarf virus. BYDV: Genotype x insecticide studies - 81MN14, 81MT29, 81E28, 81MN14. BYDV: differences amongst barley genotypes - 81C19, 81WH31, 81BA30. BYDV: Resistance and yield in CV.Shannon and CV. Proctor - 871BR13, 81MA8, 81AL36, 81JE17 Yield per plot and 100 seed weight - Albany 81AL36 Infection of BYDV in cereal genotypes at Manjimup ( 81MN13)

    Interpolation of Hilbert and Sobolev Spaces: Quantitative Estimates and Counterexamples

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    This paper provides an overview of interpolation of Banach and Hilbert spaces, with a focus on establishing when equivalence of norms is in fact equality of norms in the key results of the theory. (In brief, our conclusion for the Hilbert space case is that, with the right normalisations, all the key results hold with equality of norms.) In the final section we apply the Hilbert space results to the Sobolev spaces Hs(Ω)H^s(\Omega) and H~s(Ω)\widetilde{H}^s(\Omega), for sRs\in \mathbb{R} and an open ΩRn\Omega\subset \mathbb{R}^n. We exhibit examples in one and two dimensions of sets Ω\Omega for which these scales of Sobolev spaces are not interpolation scales. In the cases when they are interpolation scales (in particular, if Ω\Omega is Lipschitz) we exhibit examples that show that, in general, the interpolation norm does not coincide with the intrinsic Sobolev norm and, in fact, the ratio of these two norms can be arbitrarily large

    Symplectic cohomology and q-intersection numbers

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    Given a symplectic cohomology class of degree 1, we define the notion of an equivariant Lagrangian submanifold. The Floer cohomology of equivariant Lagrangian submanifolds has a natural endomorphism, which induces a grading by generalized eigenspaces. Taking Euler characteristics with respect to the induced grading yields a deformation of the intersection number. Dehn twists act naturally on equivariant Lagrangians. Cotangent bundles and Lefschetz fibrations give fully computable examples. A key step in computations is to impose the "dilation" condition stipulating that the BV operator applied to the symplectic cohomology class gives the identity. Equivariant Lagrangians mirror equivariant objects of the derived category of coherent sheaves.Comment: 32 pages, 9 figures, expanded introduction, added details of example 7.5, added discussion of sign

    Two-finger selection theory in the Saffman-Taylor problem

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    We find that solvability theory selects a set of stationary solutions of the Saffman-Taylor problem with coexistence of two \it unequal \rm fingers advancing with the same velocity but with different relative widths λ1\lambda_1 and λ2\lambda_2 and different tip positions. For vanishingly small dimensionless surface tension d0d_0, an infinite discrete set of values of the total filling fraction λ=λ1+λ2\lambda = \lambda_1 + \lambda_2 and of the relative individual finger width p=λ1/λ2p=\lambda_1/\lambda_2 are selected out of a two-parameter continuous degeneracy. They scale as λ1/2d02/3\lambda-1/2 \sim d_0^{2/3} and p1/2d01/3|p-1/2| \sim d_0^{1/3}. The selected values of λ\lambda differ from those of the single finger case. Explicit approximate expressions for both spectra are given.Comment: 4 pages, 3 figure

    Spin-2 Amplitudes in Black-Hole Evaporation

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    Quantum amplitudes for s=2s=2 gravitational-wave perturbations of Einstein/scalar collapse to a black hole are treated by analogy with s=1s=1 Maxwell perturbations. The spin-2 perturbations split into parts with odd and even parity. We use the Regge-Wheeler gauge; at a certain point we make a gauge transformation to an asymptotically-flat gauge, such that the metric perturbations have the expected falloff behaviour at large radii. By analogy with s=1s=1, for s=2s=2 natural 'coordinate' variables are given by the magnetic part Hij(i,j=1,2,3)H_{ij} (i,j=1,2,3) of the Weyl tensor, which can be taken as boundary data on a final space-like hypersurface ΣF\Sigma_F. For simplicity, we take the data on the initial surface ΣI\Sigma_I to be exactly spherically-symmetric. The (large) Lorentzian proper-time interval between ΣI\Sigma_I and ΣF\Sigma_F, measured at spatial infinity, is denoted by TT. We follow Feynman's +iϵ+i\epsilon prescription and rotate TT into the complex: TTexp(iθ)T\to{\mid}T{\mid} \exp(-i\theta), for 0<θπ/20<\theta\leq\pi/2. The corresponding complexified {\it classical} boundary-value problem is expected to be well-posed. The Lorentzian quantum amplitude is recovered by taking the limit as θ0+\theta\to 0_+. For boundary data well below the Planck scale, and for a locally supersymmetric theory, this involves only the semi-classical amplitude exp(iSclass(2)\exp(iS^{(2)}_{\rm class}, where Sclass(2)S^{(2)}_{\rm class} denotes the second-variation classical action. The relations between the s=1s=1 and s=2s=2 natural boundary data, involving supersymmetry, are investigated using 2-component spinor language in terms of the Maxwell field strength ϕAB=ϕ(AB)\phi_{AB}=\phi_{(AB)} and the Weyl spinor ΨABCD=Ψ(ABCD)\Psi_{ABCD}=\Psi_{(ABCD)}

    Scaling Relations of Viscous Fingers in Anisotropic Hele-Shaw Cells

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    Viscous fingers in a channel with surface tension anisotropy are numerically studied. Scaling relations between the tip velocity v, the tip radius and the pressure gradient are investigated for two kinds of boundary conditions of pressure, when v is sufficiently large. The power-law relations for the anisotropic viscous fingers are compared with two-dimensional dendritic growth. The exponents of the power-law relations are theoretically evaluated.Comment: 5 pages, 4 figure

    Failure of interpolation in the intuitionistic logic of constant domains

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    This paper shows that the interpolation theorem fails in the intuitionistic logic of constant domains. This result refutes two previously published claims that the interpolation property holds.Comment: 13 pages, 0 figures. Overlaps with arXiv 1202.1195 removed, the text thouroughly reworked in terms of notation and style, historical notes as well as some other minor details adde
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