64 research outputs found

    New Orthopteroid Records in Michigan Derived from Sampling a Small Field

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    (excerpt) A 1.8 acre sandy field in Isabella County, Michigan was sampled in 1971 and 1972 to obtain data on ecological and chronological distribution of orthopteroid species (Bland and Swayze 1973a,b). The upland field vegetation was a mosaic of numerous non- contiguous floral associations (e.g. moss-grass, grass-milkweed, goldenrod-bergamot-fern) made up of 58 plant species. The land, bordered by shrubs, trees and a road, was relatively isolated. Sampling was done both day and night once a week by using sweep nets and 7 to 21 pit traps (some containing molasses as bait)

    New Distribution Records for Mosquitoes in Michigan (Diptera: Culicidae)

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    (excerpt) Since the late 1940\u27s very little information has appeared in the literature dealing with the geographical distribution of mosquitoes in Michigan. The earliest attempt at establish- ing a comprehensive list of species was made by Irwin (1941) who catalogued 43 species by county. A survey by Pederson (1947) resulted in the collection of 48 species and provided the most extensive distribution list of mosquitoes in Michigan. Recent studies by Newson et al. (1975), McGroarty et al. (1976) and Grimstad (1977) have contributed several new distribution and state records. Prompted by the 1975 St. Louis encephalitis outbreak in Michigan, and a lack of current information on the species of mosquitoes in Isabella County, a survey of mosquitoes was conducted in the Mount Pleasant area

    GNOSIS: the first instrument to use fibre Bragg gratings for OH suppression

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    GNOSIS is a prototype astrophotonic instrument that utilizes OH suppression fibres consisting of fibre Bragg gratings and photonic lanterns to suppress the 103 brightest atmospheric emission doublets between 1.47-1.7 microns. GNOSIS was commissioned at the 3.9-meter Anglo-Australian Telescope with the IRIS2 spectrograph to demonstrate the potential of OH suppression fibres, but may be potentially used with any telescope and spectrograph combination. Unlike previous atmospheric suppression techniques GNOSIS suppresses the lines before dispersion and in a manner that depends purely on wavelength. We present the instrument design and report the results of laboratory and on-sky tests from commissioning. While these tests demonstrated high throughput and excellent suppression of the skylines by the OH suppression fibres, surprisingly GNOSIS produced no significant reduction in the interline background and the sensitivity of GNOSIS and IRIS2 is about the same as IRIS2. It is unclear whether the lack of reduction in the interline background is due to physical sources or systematic errors as the observations are detector noise-dominated. OH suppression fibres could potentially impact ground-based astronomy at the level of adaptive optics or greater. However, until a clear reduction in the interline background and the corresponding increasing in sensitivity is demonstrated optimized OH suppression fibres paired with a fibre-fed spectrograph will at least provide a real benefits at low resolving powers.Comment: 15 pages, 13 figures, accepted to A

    The SAMI Galaxy Survey: Global stellar populations on the size-mass plane

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    We present an analysis of the global stellar populations of galaxies in the SAMI Galaxy Survey. Our sample consists of 1319 galaxies spanning four orders of magnitude in stellar mass and includes all morphologies and environments. We derive luminosity-weighted, single stellar population equivalent stellar ages, metallicities and alpha enhancements from spectra integrated within one effective radius apertures. Variations in galaxy size explain the majority of the scatter in the age--mass and metallicity--mass relations. Stellar populations vary systematically in the plane of galaxy size and stellar mass, such that galaxies with high stellar surface mass density are older, more metal-rich and alpha-enhanced than less dense galaxies. Galaxies with high surface mass densities have a very narrow range of metallicities, however, at fixed mass, the spread in metallicity increases substantially with increasing galaxy size (decreasing density). We identify residual correlations with morphology and environment. At fixed mass and size, galaxies with late-type morphologies, small bulges and low Sersic n are younger than early-type, high n, high bulge-to-total galaxies. Age and metallicity both show small residual correlations with environment; at fixed mass and size, galaxies in denser environments or more massive halos are older and somewhat more metal rich than those in less dense environments. We connect these trends to evolutionary tracks within the size--mass plane.Comment: 25 pages, 18 figures, MNRAS in press Corrected typo in author lis

    Search for Fractional Charges Produced in Heavy-Ion Collisions at 1.9 GeV/nucleon

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    An experiment was performed to capture fractionally charged particles produced in heavy-ion collisions and to concentrate them in samples suitable for analysis by various techniques. Two of the samples so produced have been searched, with use of an automated version of Millikan\u27s oil-drop apparatus. The beam was 56Fe at 1.9 GeV/nucleon, incident on a lead target. Less than one fractional charge per 1.0× 104 Fe-Pb collisions was found to be produced, and, with further assumptions, less than one per 2.0× 106 collisions

    GNOSIS: The first instrument to use fiber bragg gratings for OH suppression

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    The near-infrared is an important part of the spectrum in astronomy, especially in cosmology because the light from objects in the early universe is redshifted to these wavelengths. However, deep near-infrared observations are extremely difficult to makeThe GNOSIS team acknowledges funding by ARC LIEF grant LE100100164. C.Q.T. gratefully acknowledges support by the National Science Foundation Graduate Research Fellowship under grant No. DGE-1035963

    Continued Use of Exogenic Materials found on Mars as Planetary Research Tools

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    Exogenic materials (meteorites, micrometeorites and chemical tracers) are encountered both serendipitously and as campaign targets during Mars rover terrain traverse and reconnaissance. We advocate the continued study of these materials in-situ when encountered and permitted by extended and new Mars surface missions in the 2023–2032 decade.Whitepaper submitted to the Planetary Science and Astrobiology Decadal Survey 2023-2032. Additional co-authors: Sara Motaghian, Brandi L. Carrier, William H. Farrand, Marc D. Fries, Peter Grindrod, Andrew Langedam, Jérémie Lasue

    Improved Detection of Bifidobacteria with Optimised 16S rRNA-Gene Based Pyrosequencing

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    The 16S rRNA gene is conserved across all bacteria and as such is routinely targeted in PCR surveys of bacterial diversity. PCR primer design aims to amplify as many different 16S rRNA gene sequences from as wide a range of organisms as possible, though there are no suitable 100% conserved regions of the gene, leading to bias. In the gastrointestinal tract, bifidobacteria are a key genus, but are often under-represented in 16S rRNA surveys of diversity. We have designed modified, ‘bifidobacteria-optimised’ universal primers, which we have demonstrated detection of bifidobacterial sequence present in DNA mixtures at 2% abundance, the lowest proportion tested. Optimisation did not compromise the detection of other organisms in infant faecal samples. Separate validation using fluorescence in situ hybridisation (FISH) shows that the proportions of bifidobacteria detected in faecal samples were in agreement with those obtained using 16S rRNA based pyrosequencing. For future studies looking at faecal microbiota, careful selection of primers will be key in order to ensure effective detection of bifidobacteria
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