742 research outputs found

    Research and management implications of the pursuit of black bears with trained bear dogs

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    Survival, Nest Success and Productivity of Female Common Eiders (Somateria mollissima dresseri) on Flag Island, Harspwell, Casco Bay, Maine

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    In 2008, we concluded the 6th and final year of what was originally designed as a 5-year study to examine survival, recruitment and recovery rates of nesting common eiders (Somateria mollissima dresseri) on Flag Island, Harpswell, Maine. The total breeding population of common eiders on Flag Island was estimated to be about 500 nesting pairs in 2008, which is at the long term estimate of approximately 500-600 nesting pairs for this island. Both the 2007 and 2008 nesting estimates were, however, a marked improvement from the 2006 estimate when only 200 hens actually nested. This low point coincided with the beginning of significant non-nesting events by hen eiders in east Casco Bay at and leading up to two significant mortality events on the wintering grounds in Massachusetts. One cause contributing to these die-offs was determined to by an RNA virus. Nest success over the duration of this study was high at 75% in 2005, 74% in 2006 to 89% in 2007. Although the percentage of nesting great black-backed gulls increased during this investigation, the overall size of the nesting gull population remained fairly constant

    An exploration of the effectiveness of artificial mini-magnetospheres as a potential solar storm shelter for long term human space missions

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    If mankind is to explore the solar system beyond the confines of our Earth and Moon the problem of radiation protection must be addressed. Galactic cosmic rays and highly variable energetic solar particles are an ever-present hazard in interplanetary space. Electric and/or magnetic fields have been suggested as deflection shields in the past, but these treated space as an empty vacuum. In fact it is not empty. Space contains a plasma known as the solar wind; a constant flow of protons and electrons coming from the Sun. In this paper we explore the effectiveness of a “mini-magnetosphere” acting as a radiation protection shield. We explicitly include the plasma physics necessary to account for the solar wind and its induced effects. We show that, by capturing/containing this plasma, we enhance the effectiveness of the shield. Further evidence to support our conclusions can be obtained from studying naturally occurring “mini-magnetospheres” on the Moon. These magnetic anomalies (related to “lunar swirls”) exhibit many of the effects seen in laboratory experiments and computer simulations. If shown to be feasible, this technology could become the gateway to manned exploration of interplanetary space

    Excitation of EMIC waves detected by the Van Allen Probes on 28 April 2013

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    Abstract We report the wave observations, associated plasma measurements, and linear theory testing of electromagnetic ion cyclotron (EMIC) wave events observed by the Van Allen Probes on 28 April 2013. The wave events are detected in their generation regions as three individual events in two consecutive orbits of Van Allen Probe-A, while the other spacecraft, B, does not detect any significant EMIC wave activity during this period. Three overlapping H+ populations are observed around the plasmapause when the waves are excited. The difference between the observational EMIC wave growth parameter (Eh) and the theoretical EMIC instability parameter (Sh) is significantly raised, on average, to 0.10 ± 0.01, 0.15 ± 0.02, and 0.07 ± 0.02 during the three wave events, respectively. On Van Allen Probe-B, this difference never exceeds 0. Compared to linear theory (Eh\u3eSh), the waves are only excited for elevated thresholds

    The Grand Tour of the Ruby-East Humboldt Metamorphic Core Complex, Northeastern Nevada: Part 1-Introduction & Road Log

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    The purpose of this geological excursion is to provide an overview of the multiphase developmental history of the Ruby Mountains and East Humboldt Range, northeastern Nevada. Although these mountain ranges are commonly cited as a classic example of a Cordilleran metamorphic core complex developed through large-magnitude, mid-Tertiary crustal extension, a preceding polyphase Mesozoic contractional history is also well preserved in the ranges. An early phase of this history involved Late Jurassic two-mica granitic magmatism, high-temperature but relatively low-pressure metamorphism, and polyphase deformation in the central Ruby Mountains. In the northern Ruby Mountains and East Humboldt Range, a Late Cretaceous history of crustal shortening, metamorphism, and magmatism is manifested by fold-nappes (involving Archean basement rocks in the northern East Humboldt Range), widespread migmatization, injection of monzogranitic and leucogranitic magmas, all coupled with sillimanite-grade metamorphism. Following Late Cretaceous contraction, a protracted extensional deformation partially overprinted these areas during the Cenozoic. This extensional history may have begun as early as the Late Cretaceous or as late as the mid-Eocene. Late Eocene and Oligocene magmatism occurred at various levels in the crust yielding mafic to felsic orthogneisses in the deep crust, a composite granitic pluton in the upper crust, and volcanic rocks at the surface. Movement along a west-rooted, extensional shear zone in the Oligocene and early Miocene led to core-complex exhumation. The shear zone produced mylonitic rocks about 1 km thick at deep crustal levels, and an overprint of brittle detachment faulting at shallower levels as unroofing proceeded. Megabreccias and other synextensional sedimentary deposits are locally preserved in a tilted, upper Eocene through Miocene stratigraphic sequence. Neogene magmatism included the emplacement of basalt dikes and eruption of rhyolitic rocks. Subsequent Basin and Range normal faulting, as young as Holocene, records continued tectonic extension

    Analyzing the Large-Scale Bulk Flow using CosmicFlows4: Increasing Tension with the Standard Cosmological Model

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    We present an estimate of the bulk flow in a volume of radii 150200h1150-200h^{-1}Mpc using the minimum variance (MV) method with data from the CosmicFlows-4 (CF4) catalog. The addition of new data in the CF4 has resulted in an increase in the estimate of the bulk flow in a sphere of radius 150h1150h^{-1}Mpc relative to the CosmicFlows-3 (CF3). This bulk flow has less than a 0.03%0.03\% chance of occurring in the Standard Cosmological Model (Λ\LambdaCDM) with cosmic microwave background derived parameters. Given that the CF4 is deeper than the CF3, we were able to use the CF4 to accurately estimate the bulk flow on scales of 200h1200h^{-1}Mpc (equivalent to 266 Mpc for Hubble constant Ho=75H_o=75 km/s/Mpc) for the first time. This bulk flow is in even greater tension with the Standard Model, having less than 0.003%0.003\% probability of occurring. To estimate the bulk flow accurately, we introduce a novel method to calculate distances and velocities from distance moduli that is unbiased and accurate at all distances. Our results are completely independent of the value of HoH_o.Comment: 9 pages, 8 figures, 1 tabl

    Evaluation of glycoproteins purified from adult and larval camel ticks (Hyalomma dromedarii) as a candidate vaccine

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    In order to identify antigens that can help prevent camel tick infestations, three major glycoproteins (GLPs) about 97, 66 and 40 kDa in size were purified from adult and larval Egyptian ticks, Hyalomma (H.) dromedarii, using a single-step purification method with Con-A sepharose. The purified GLPs were evaluated as vaccines against camel tick infestation in rabbits. The rabbits received three intramuscular inoculations of GLPs (20 µg/animal) on days 0, 14, and 28. In the immunoblot analysis, Sera from the immunized rabbits recognized the native GLPs and other proteins from larval and adult H. dromedarii ticks along with those from other tick species such as Rhipicephalus sanguineus but not Ornithodoros moubata. The effects of immunity induced by these GLPs were determined by exposing rabbits to adult H. dromedarii ticks. These results demonstrated that GLP immunization led to a slightly decreased reproductive index and significantly reduced rates of egg hatchability. These results demonstrated that immunization with the purified GLPs can provide protection against infestation by H. dromedarii and some other tick species. Further studies are needed to confirm the effectiveness of immunization with GLPs against other tick species
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