924 research outputs found

    Relativistic ideal Fermi gas at zero temperature and preferred frame

    Full text link
    We discuss the limit T->0 of the relativistic ideal Fermi gas of luxons (particles moving with the speed of light) and tachyons (hypothetical particles faster than light) based on observations of our recent paper: K. Kowalski, J. Rembielinski and K.A. Smolinski, Phys. Rev. D, 76, 045018 (2007). For bradyons this limit is in fact the nonrelativistic one and therefore it is not studied herein

    Effect of Milk on Fibronectin and Collagen Type I Binding to \u3ci\u3eStaphylococcus aureus\u3c/i\u3e and Coagulase-Negative Staphylococci Isolated from Bovine Mastitis

    Get PDF
    Tryptic soy broth (TSB)-grown cells of Staphylococcus aureus isolated from acute and chronic bovine mastitis bound mainly 125I-fibronectin (125I-Fn), whereas strains of nine species of coagulase-negative staphylococci showed a predominant interaction with 125I-collagen (125I-Cn) type I. A particle agglutination assay (PAA) was used to examine the interaction of coagulase-negative staphylococci with 1251-Fn and 125I-Cn immobilized on latex. All 368 coagulase-negative staphylococci demonstrated high 125I-Cn and moderate to low 125I-Fn interactions in the PAA. Cn-PAA reactivity was high among strains of Staphylococcus xylosus (84.2%), Staphylococcus simulans (77.8%), Staphylococcus epidermidis (76.7%), and Staphylococcus hyicus (74.3%), whereas all six Staphylococcus capitis strains clumped Cn-PAA reagent. Incubating TSB-grown cells in 10% skim milk for 1 h decreased the 125I-Fn- and 125I-Cn-binding affinity in most of the S. aureus and coagulase-negative staphylococci, while growth in 10% skim milk for 18 h resulted in more than 90% decrease or complete loss of interaction with these proteins. Decreased 1251-Fn binding in the presence of milk was correlated with protease production but not with 125I-Cn binding

    Effect of Milk on Fibronectin and Collagen Type I Binding to \u3ci\u3eStaphylococcus aureus\u3c/i\u3e and Coagulase-Negative Staphylococci Isolated from Bovine Mastitis

    Get PDF
    Tryptic soy broth (TSB)-grown cells of Staphylococcus aureus isolated from acute and chronic bovine mastitis bound mainly 125I-fibronectin (125I-Fn), whereas strains of nine species of coagulase-negative staphylococci showed a predominant interaction with 125I-collagen (125I-Cn) type I. A particle agglutination assay (PAA) was used to examine the interaction of coagulase-negative staphylococci with 1251-Fn and 125I-Cn immobilized on latex. All 368 coagulase-negative staphylococci demonstrated high 125I-Cn and moderate to low 125I-Fn interactions in the PAA. Cn-PAA reactivity was high among strains of Staphylococcus xylosus (84.2%), Staphylococcus simulans (77.8%), Staphylococcus epidermidis (76.7%), and Staphylococcus hyicus (74.3%), whereas all six Staphylococcus capitis strains clumped Cn-PAA reagent. Incubating TSB-grown cells in 10% skim milk for 1 h decreased the 125I-Fn- and 125I-Cn-binding affinity in most of the S. aureus and coagulase-negative staphylococci, while growth in 10% skim milk for 18 h resulted in more than 90% decrease or complete loss of interaction with these proteins. Decreased 1251-Fn binding in the presence of milk was correlated with protease production but not with 125I-Cn binding

    Phylogenies of Microcystin-Producing Cyanobacteria in the Lower Laurentian Great Lakes Suggest Extensive Genetic Connectivity

    Get PDF
    Lake St. Clair is the smallest lake in the Laurentian Great Lakes system. MODIS satellite imagery suggests that high algal biomass events have occurred annually along the southern shore during late summer. In this study, we evaluated these events and tested the hypothesis that summer bloom material derived from Lake St. Clair may enter Lake Erie via the Detroit River and represent an overlooked source of potentially toxic Microcystis biomass to the western basin of Lake Erie. We conducted a seasonally and spatially resolved study carried out in the summer of 2013. Our goals were to: 1) track the development of the 2013 summer south-east shore bloom 2) conduct a spatial survey to characterize the extent of toxicity, taxonomic diversity of the total phytoplankton population and the phylogenetic diversity of potential MC-producing cyanobacteria (Microcystis, Planktothrix and Anabaena) during a high biomass event, and 3) compare the strains of potential MC-producers in Lake St. Clair with strains from Lake Erie and Lake Ontario. Our results demonstrated a clear predominance of cyanobacteria during a late August bloom event, primarily dominated by Microcystis, which we traced along the Lake St. Clair coastline downstream to the Detroit River's outflow at Lake Erie. Microcystin levels exceeded the Province of Ontario Drinking Water Quality Standard (1.5 µg L(-1)) for safe drinking water at most sites, reaching up to five times this level in some areas. Microcystis was the predominant microcystin producer, and all toxic Microcystis strains found in Lake St. Clair were genetically similar to toxic Microcystis strains found in lakes Erie and Ontario. These findings suggest extensive genetic connectivity among the three systems

    A lattice calculation of vector meson couplings to the vector and tensor currents using chirally improved fermions

    Full text link
    We present a quenched lattice calculation of fV/fVf_V^\perp/f_V, the coupling of vector mesons to the tensor current normalized by the vector meson decay constant. The chirally improved lattice Dirac operator, which allows us to reach small quark masses, is used. We put emphasis on analyzing the quark mass dependence of fV/fVf_V^\perp/f_V and find only a rather weak dependence. Our results at the ρ\rho and ϕ\phi masses agree well with QCD sum rule calculations and those from previous lattice studies.Comment: 6 pages, 3 figures, one sentence remove

    Joint analysis of stressors and ecosystem services to enhance restoration effectiveness

    Get PDF
    With increasing pressure placed on natural systems by growing human populations, both scientists and resource managers need a better understanding of the relationships between cumulative stress from human activities and valued ecosystem services. Societies often seek to mitigate threats to these services through large-scale, costly restoration projects, such as the over one billion dollar Great Lakes Restoration Initiative currently underway. To help inform these efforts, we merged high-resolution spatial analyses of environmental stressors with mapping of ecosystem services for all five Great Lakes. Cumulative ecosystem stress is highest in near-shore habitats, but also extends offshore in Lakes Erie, Ontario, and Michigan. Variation in cumulative stress is driven largely by spatial concordance among multiple stressors, indicating the importance of considering all stressors when planning restoration activities. In addition, highly stressed areas reflect numerous different combinations of stressors rather than a single suite of problems, suggesting that a detailed understanding of the stressors needing alleviation could improve restoration planning. We also find that many important areas for fisheries and recreation are subject to high stress, indicating that ecosystem degradation could be threatening key services. Current restoration efforts have targeted high-stress sites almost exclusively, but generally without knowledge of the full range of stressors affecting these locations or differences among sites in service provisioning. Our results demonstrate that joint spatial analysis of stressors and ecosystem services can provide a critical foundation for maximizing social and ecological benefits from restoration investments. www.pnas.org/lookup/suppl/doi:10.1073/pnas.1213841110/-/DCSupplementa

    Four Flats Poster

    Get PDF
    Poster for a Four Flats reunion concerts at Porland Civic Auditorium, Oregon. 1 page, black and white.https://digitalcommons.georgefox.edu/fourflats_papers/1014/thumbnail.jp

    Flavor SU(3) breaking effects in the chiral unitary model for meson-baryon scatterings

    Full text link
    We examine flavor SU(3) breaking effects on meson-baryon scattering amplitudes in the chiral unitary model. It turns out that the SU(3) breaking, which appears in the leading quark mass term in the chiral expansion, can not explain the channel dependence of the subtraction parameters of the model, which are crucial to reproduce the observed scattering amplitudes and resonance properties.Comment: RevTeX4, 4 pages, 3 figures, 2 table
    corecore