51,603 research outputs found

    Testing of Great Bay Oysters for Two Protozoan Pathogens

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    Two protozoan pathogens, Haplosporidium nelsoni (MSX) and Perkinsus marinus (Dermo) are known to be present in Great Bay oysters. With funds provided by the New Hampshire Estuaries Project (NHEP), the Marine Fisheries Division of New Hampshire Fish and Game Department, (NHF&G) continues to assess the presence and intensity of both disease conditions in oysters from the major beds, some open for harvest, within the Great Bay estuarine system. Histological examination of Great Bay oysters has also revealed other endoparasites

    Testing of Great Bay Oysters for Two Protozoan Pathogens

    Get PDF
    Two protozoan pathogens, Haplosporidium nelsoni (MSX) and Perkinsus marinus(Dermo) are known to be present in Great Bay oysters. With funds provided by the New Hampshire Estuaries Project (NHEP), the Marine Fisheries Division of New Hampshire Fish and Game Department, (NHF&G) continues to assess the presence and intensity of both disease conditions in oysters from the major beds, some open for harvest, within the Great Bay estuarine system. Histological examination of Great Bay oysters has also revealed other endoparasites

    Non-Hermitian Luttinger Liquids and Vortex Physics

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    As a model of two thermally excited flux liquids connected by a weak link, we study the effect of a single line defect on vortex filaments oriented parallel to the surface of a thin planar superconductor. When the applied field is tilted relative to the line defect, the physics is described by a nonhermitian Luttinger liquid of interacting quantum bosons in one spatial dimension with a point defect. We analyze this problem using a combination of analytic and numerical density matrix renormalization group methods, uncovering a delicate interplay between enhancement of pinning due to Luttinger liquid effects and depinning due to the tilted magnetic field. Interactions dramatically improve the ability of a single columnar pin to suppress vortex tilt when the Luttinger liquid parameter g is less than or equal to one.Comment: 4 pages, 5 eps figures, minor changes made, one reference adde

    High field transport in strained Si/GeSi double heterostructure: a Fokker-Planck approach

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    We report calculations of high electric field transport for the case of a strained Si/GeSi double heterostructure (DHS) considering transport along the Si channel and by applying the analytical Fokker-Planck approach (FPA), where the process is modeled as drift-diffusion in energy space. We limit ourselves to electronic transport in the conduction band of the strained Si, where an energy shift between the otherwise degenerate six energy valleys characterizes the band alingment in the DHS. Intervalley phonon scatterings are considered while intravalley acoustic phonon scattering is ignored, leading to results valid for high enough temperatures. Our results are compared to previous theoretical works where Monte Carlo simulations were applied. A reasonable agreement between the two approaches is obtained in the high electric field regime.Comment: 8 pages, 3 figure

    Crumpling transition of the triangular lattice without open edges: effect of a modified folding rule

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    Folding of the triangular lattice in a discrete three-dimensional space is investigated by means of the transfer-matrix method. This model was introduced by Bowick and co-workers as a discretized version of the polymerized membrane in thermal equilibrium. The folding rule (constraint) is incompatible with the periodic-boundary condition, and the simulation has been made under the open-boundary condition. In this paper, we propose a modified constraint, which is compatible with the periodic-boundary condition; technically, the restoration of translational invariance leads to a substantial reduction of the transfer-matrix size. Treating the cluster sizes L \le 7, we analyze the singularities of the crumpling transitions for a wide range of the bending rigidity K. We observe a series of the crumpling transitions at K=0.206(2), -0.32(1), and -0.76(10). At each transition point, we estimate the latent heat as Q=0.356(30), 0.08(3), and 0.05(5), respectively

    Testing of Great Bay Oysters for Two Protazoan Pathogens

    Get PDF
    Two protozoan pathogens, Haplosporidium nelsoni (MSX) and Perkinsus marinus (Dermo) are known to be present in Great Bay oysters. With funds provided by the New Hampshire Estuaries Project (NHEP), the Marine Fisheries Division of New Hampshire Fish and Game Department, (NHF&G) continues to assess the presence and intensity of both disease conditions in oysters from the major beds, some open for harvest, within the Great Bay estuarine system. Histological examination of Great Bay oysters has also revealed other endoparasites

    Folding of the triangular lattice in a discrete three-dimensional space: Crumpling transitions in the negative-bending-rigidity regime

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    Folding of the triangular lattice in a discrete three-dimensional space is studied numerically. Such ``discrete folding'' was introduced by Bowick and co-workers as a simplified version of the polymerized membrane in thermal equilibrium. According to their cluster-variation method (CVM) analysis, there appear various types of phases as the bending rigidity K changes in the range -infty < K < infty. In this paper, we investigate the K<0 regime, for which the CVM analysis with the single-hexagon-cluster approximation predicts two types of (crumpling) transitions of both continuous and discontinuous characters. We diagonalized the transfer matrix for the strip widths up to L=26 with the aid of the density-matrix renormalization group. Thereby, we found that discontinuous transitions occur successively at K=-0.76(1) and -0.32(1). Actually, these transitions are accompanied with distinct hysteresis effects. On the contrary, the latent-heat releases are suppressed considerably as Q=0.03(2) and 0.04(2) for respective transitions. These results indicate that the singularity of crumpling transition can turn into a weak-first-order type by appreciating the fluctuations beyond a meanfield level

    How effective is harassment on infalling late-type dwarfs?

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    A new harassment model is presented that models the complex, and dynamical tidal field of a Virgo like galaxy cluster. The model is applied to small, late-type dwarf disc galaxies (of substantially lower mass than in previous harassment simulations) as they infall into the cluster from the outskirts. These dwarf galaxies are only mildly affected by high speed tidal encounters with little or no observable consequences; typical stellar losses are <10%<10\%, producing very low surface brightness streams (μB>31\mu_B > 31 mag arcsec2^{-2}), and a factor of two drop in dynamical mass-to-light ratio. Final stellar discs remain disc-like, and dominated by rotation although often with tidally induced spiral structure. By means of Monte-Carlo simulations, the statistically likely influences of harassment on infalling dwarf galaxies are determined. The effects of harassment are found to be highly dependent on the orbit of the galaxy within the cluster, such that newly accreted dwarf galaxies typically suffer only mild harassment. Strong tidal encounters, that can morphologically transform discs into spheroidals, are rare occurring in <15%<15 \% of dwarf galaxy infalls for typical orbits of sub-structure within Λ\LambdaCDM cluster mass halos. For orbits with small apocentric distances (<<250 kpc), harassment is significantly stronger resulting in complete disruption or heavy mass loss (>90%>90 \% dark matter and >50%> 50 \% stellar), however, such orbits are expected to be highly improbable for newly infalling galaxies due to the deep potential well of the cluster.Comment: 15 pages, 11 figures, 4 table
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