1,113 research outputs found

    Geomorphic processes active in the Southwestern Louisiana Canal, Lafourche Parish, Louisiana

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    The geomorphological changes causing the destruction of the banks of the Southwestern Louisiana Canal are studied by means of field work, laboratory analyses, and infrared color imagery interpretation. Turbulence and flow patterns are mapped, and related to erosion and sediment deposition processes. The accelerated erosion rate of the last decade is discussed, with two causative factors cited: (1) development of faster boats, increasing bank and bottom erosion, and (2) a subsequently larger tidal influx, with greater erosive ability. The physical properties of the canal bank materials are also analyzed. It is concluded that channel erosion progressively increases, with no indications of stabilization, until they merge with other waterways and become indistinguishable from natural water bodies

    A Fourier transform spectrometer for visible and near ultra-violet measurements of atmospheric absorption

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    The development of a prototype, ground-based, Sun-pointed Michelson interferometric spectrometer is described. Its intended use is to measure the atmospheric amount of various gases which absorb in the near-infrared, visible, and near-ultraviolet portions of the electromagnetic spectrum. Preliminary spectra which contain the alpha, 0.8 micrometer, and rho sigma tau water vapor absorption bands in the near-infrared are presented to indicate the present capability of the system. Ultimately, the spectrometer can be used to explore the feasible applications of Fourier transform spectroscopy in the ultraviolet where grating spectrometers were used exclusively

    Remote sensing as an aid to route evaluation for relocated Louisiana Highway 1

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    NASA aerial photography in the form of color infrared and color positive transparencies is used as an aid for evaluation of the route proposed for relocated Louisiana Highway 1, between LaRose and Golden Meadow, in South Louisiana

    The use of color infrared imagery for the study of marsh buggy tracks

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    Color infrared imagery is used to determine the location of buggy routes and to quantify the extent of tracks in a selected area where the marsh is seriously dissected. The imagery is used to show successive stages of destruction. It is recommended that alternate routes be identified in the operating area to eliminate continuous use of the same route and facilitate faster revegetation

    Caffeine enhances upper body strength in resistance-trained women

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    BACKGROUND: Research has indicated that low-to-moderate dosages of caffeine supplementation are ergogenic for sustained endurance efforts as well as high-intensity exercise. The effects of caffeine supplementation on strength-power performance are equivocal, with some studies indicating a benefit and others demonstrating no change in performance. The majority of research that has examined the effects of caffeine supplementation on strength-power performance has been carried out in both trained and untrained men. Therefore, the purpose of this study was to determine the acute effects of caffeine supplementation on strength and muscular endurance in resistance-trained women. METHODS: In a randomized manner, 15 women consumed caffeine (6 mg/kg) or placebo (PL) seven days apart. Sixty min following supplementation, participants performed a one-repetition maximum (1RM) barbell bench press test and repetitions to failure at 60% of 1RM. Heart rate (HR) and blood pressure (BP) were assessed at rest, 60 minutes post-consumption, and immediately following completion of repetitions to failure. RESULTS: Repeated measures ANOVA indicated a significantly greater bench press maximum with caffeine (p CONCLUSIONS: These findings indicate a moderate dose of caffeine may be sufficient for enhancing strength performance in resistance-trained women

    Optical and Infrared Light Curves of the Eclipsing X-ray Binary V395 Car = 2S 0921-630

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    We present results of optical and infrared photometric monitoring of the eclipsing low-mass X-ray binary V395 Car (2S 0921-630). Our observations reveal a clear, repeating orbital modulation with an amplitude of about one magnitude in B, and V and a little less in J. Combining our data with archival observations spanning about 20 years, we derive an updated ephemeris with orbital period 9.0026+/-0.0001d. We attribute the modulation to a combination of the changing aspect of the irradiated face of the companion star and eclipses of the accretion disk around the neutron star. Both appear to be necessary as a secondary eclipse of the companion star is clearly seen. We model the B, V, and J lightcurves using a simple model of an accretion disk and companion star and find a good fit is possible for binary inclinations of 82.2+/-1.0 degrees. We estimate the irradiating luminosity to be about 8x10^35 erg/s, in good agreement with X-ray constraints.Comment: 6 pages, accepted for publication in MNRA

    Using binary stars to bound the mass of the graviton

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    Interacting white dwarf binary star systems, including helium cataclysmic variable (HeCV) systems, are expected to be strong sources of gravitational radiation, and should be detectable by proposed space-based laser interferometer gravitational wave observatories such as LISA. Several HeCV star systems are presently known and can be studied optically, which will allow electromagnetic and gravitational wave observations to be correlated. Comparisons of the phases of a gravitational wave signal and the orbital light curve from an interacting binary white dwarf star system can be used to bound the mass of the graviton. Observations of typical HeCV systems by LISA could potentially yield an upper bound on the inverse mass of the graviton as strong as h/mg=λg>1×1015h/m_{g} = \lambda_{g} > 1 \times 10^{15} km (mg<1×1024m_{g} < 1 \times 10^{-24} eV), more than two orders of magnitude better than present solar system derived bounds.Comment: 21 pages plus 4 figures; ReVTe

    The coming North American rail mergers, 2004 July

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    Characteristics of ambulatory anticoagulant adverse drug events: a descriptive study

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    <p>Abstract</p> <p>Background</p> <p>Despite the high frequency with which adverse drug events (ADEs) occur in outpatient settings, detailed information regarding these events remains limited. Anticoagulant drugs are associated with increased safety concerns and are commonly involved in outpatient ADEs. We therefore sought to evaluate ambulatory anticoagulation ADEs and the patient population in which they occurred within the Duke University Health System (Durham, NC, USA).</p> <p>Methods</p> <p>A retrospective chart review of ambulatory warfarin-related ADEs was conducted. An automated trigger surveillance system identified eligible events in ambulatory patients admitted with an International Normalized Ratio (INR) >3 and administration of vitamin K. Event and patient characteristics were evaluated, and quality/process improvement strategies for ambulatory anticoagulation management are described.</p> <p>Results</p> <p>A total of 169 events in 167 patients were identified from December 1, 2006-June 30, 2008 and included in the study. A median supratherapeutic INR of 6.1 was noted, and roughly half of all events (52.1%) were associated with a bleed. Nearly 74% of events resulted in a need for fresh frozen plasma; 64.8% of bleeds were classified as major. A total of 59.2% of events were at least partially responsible for hospital admission. Median patient age was 68 y (range 36-95 y) with 24.9% initiating therapy within 3 months prior to the event. Of events with a prior documented patient visit (n = 157), 73.2% were seen at a Duke clinic or hospital within the previous month. Almost 80% of these patients had anticoagulation therapy addressed, but only 60.0% had a follow-up plan documented in the electronic note.</p> <p>Conclusions</p> <p>Ambulatory warfarin-related ADEs have significant patient and healthcare utilization consequences in the form of bleeding events and associated hospital admissions. Recommendations for improvement in anticoagulation management include use of information technology to assist monitoring and follow-up documentation, avoid drug interactions, and engage patients in their care.</p
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