221 research outputs found

    Diel Vertical Movements of a Scalloped Hammerhead, \u3ci\u3eSphyrna lewini\u3c/i\u3e, in the Northern Gulf of Mexico

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    Despite the circumglobal distribution of scalloped hammerheads, Sphyrna lewini (Griffith and Smith, 1834), little information is available regarding fine-scale movement and habitat use patterns for this species. Over a 27-d period, data were collected on diel habitat use and environmental preferences of a 240 cm (total length) female S. lewini. The shark exhibited a consistent and repeated diel vertical movement pattern, making more than 76 deep nighttime dives; the maximum depth reached was 964 m, where the temperature was 5.8 degrees C. The purpose of the nightly oscillatory deep diving pattern is unknown but could possibly represent feeding behavior. These findings represent the first detailed account of S. lewini diel vertical behavior and habitat utilization in the western North Atlantic Ocean

    Wave energy converter arrays: Motion response of inter-connected array

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    Compact wave energy converter (WEC) arrays are a promising option in terms of opti-mizing energy output per unit area of marine space, realizing synergies in O&M tasks and auxiliary installations (substations, export cables, etc.), and achieving economies of scale. Four different levels of connectivity between five OWC spar buoys in a compact array—corresponding to as many mooring configurations—were tested in the Ocean Basin at the University of Plymouth. We find considerable implications of the inter-connectivity on the frequency of heave motion response, with interconnected cases yielding a higher natural frequency and an increase in magnitude compared to the baseline (non-connected) arrangement. This indicates the importance of a holistic inter-connected system design approach required in the early design stages with respect to the wave climate at the deployment site. For instance, for a site off Leixões (Portugal), the frequency upshift obtained through inter-connectivity may be beneficial

    Olsen, Howey, and Owen 1 DEVELOPMENT OF A REGIONAL GIS PORTAL WITH TRANSIT DATA Corresponding Author

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    ABSTRACT The New River Valley (NRV) Metropolitan Planning Organization (MPO) recently launched a project creating a regional GIS portal in support of transit planning initiatives. The purpose of the project is to improve connections between transit providers and other modes of transportation, and to assist on-going and future transportation planning efforts at the local and regional scale. The project was conducted in two phases. Phase I included meetings with stakeholders to assess regional needs and to discuss transit-planning processes, GIS technologies, and existing data sources. Several stakeholder agencies collaborated to share transit-related data, which was cataloged and edited for public consumption. Phase II made transit data available to the public. The MPO partnered with the NRV Planning District Commission (PDC) to host the transit data on a FTP site. Using ArcGIS Online, an interactive web map was created featuring route and stop layers for the four fixed-route providers in the region. The project provided an outlet for important discussions between regional transit stakeholders and led to increased communication and collaboration between agencies. A regional transit GIS portal was created to share transit data featuring links to the FTP site, web map and additional resources regarding the MPO project

    Modelling the Innate Immune Response against Avian Influenza Virus in Chicken

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    At present there is limited understanding of the host immune response to (low pathogenic) avian influenza virus infections in poultry. Here we develop a mathematical model for the innate immune response to avian influenza virus in chicken lung, describing the dynamics of viral load, interferon-α, -β and -γ, lung (i.e. pulmonary) cells and Natural Killer cells. We use recent results from experimentally infected chickens to validate some of the model predictions. The model includes an initial exponential increase of the viral load, which we show to be consistent with experimental data. Using this exponential growth model we show that the duration until a given viral load is reached in experiments with different inoculation doses is consistent with a model assuming a linear relationship between initial viral load and inoculation dose. Subsequent to the exponential-growth phase, the model results show a decline in viral load caused by both target-cell limitation as well as the innate immune response. The model results suggest that the temporal viral load pattern in the lungs displayed in experimental data cannot be explained by target-cell limitation alone. For biologically plausible parameter values the model is able to qualitatively match to data on viral load in chicken lungs up until approximately 4 days post infection. Comparison of model predictions with data on CD107-mediated degranulation of Natural Killer cells yields some discrepancy also for earlier days post infection
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