368 research outputs found

    Effect of Clouds on Shuttle Imaging

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    This report describes the results of the AMU's task for determining the effect of clouds on optical imaging of the Space Shuttle launch vehicle during its ascent phase from lift-off to Solid Rocket Booster (SRB) Separation. This effort was motivated by Recommendation R3.4-1 from the Columbia Accident Investigation Board Report. The AMU developed a 3-dimensional (3D) model to forecast the probability that at any time from lift-off to SRB separation, at least three of the ascent imaging cameras would have a view of the Shuttle unobstructed by cloud. Because current observational and modeling capabilities do not permit accurate forecasts of cloud morphology and location, the AMU simulated obscuration of the lines-of-sight (LOS) from a network of cameras to the Shuttle by idealized cloud-fields placed randomly within the 3D domain. For each random realization of numerous cloud-field scenarios the number of simultaneous views of the Shuttle was computed from the LOS data between lift-off and SRB separation. The percent of time with 3 simultaneous views was averaged from 100 random realizations of each scenario. Analyses of the percent of time viewable were made to determine its sensitivity to cloud amount, cloud base height, cloud thickness, cloud horizontal dimensions, and an upgrade of the camera network

    Prospectus, May 2, 1984

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    SUPPORT YOUR COLLEGE! VOTE FOR STUDENT GOVERNMENT OFFICERS; News Digest; Students protest CIA campus recruitment; PC Happenings; Humanities Awards Program Summer Research; Student Government candidate platforms; Fearing suits, many colleges move to control students closely; Creative Corner...Especially for you!!; Energy from the Garden; Elf; Bums; Rites of Passage; Angie; To Those Who Have Loved and Lost...; Nuclear Weapons Freeze; Finney\u27s Famous Fanwich, on Rye; Settlement on the Sangamon; Freedom summer campaign seeks 5,000 students; Campaign for a Humane Center; Non-Event kick-off; Did you know...; Classifieds; Parkland\u27s Fine Art students\u27 work exhibited in Art Gallery; Philosophy discussion group--know yourself and your world; Top AHT students receive awards; March of Dimes plans events; Two artists exhibit work; Campus springtime; \u27The Hollywood Hall of Shame\u27 -- behind the scenes dirt; \u27Android\u27 high quality with low budget; WILL airs high drama; Sports Digest; Midwest Open successful; Parkland\u27s women\u27s basketball team finishes third offensively; Scholarships should help Parkland\u27s athletics; Cobras split with Vincennes with two from Olneyhttps://spark.parkland.edu/prospectus_1984/1022/thumbnail.jp

    Kentucky UST Field Manual

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    This study was undertaken to address the removal and closure of defective petroleum underground storage tanks in Kentucky. Goals for the study included: To address standards for levels of contamination requiring corrective action consistent with accepted scientific and technical principles. To recommend a matrix or scoring system to be used for (a) ranking sites as to actual or potential harm to human health and the environment caused by release of petroleum from a petroleum storage tank, and (2) establishing standards and procedures for corrective action that shall adequately protect human health and the environment. To address all compounds individually and collectively known as petroleum. To produce a report that shall be scientifically defensible

    Status Report: Identification of Appropriate Standards for Corrective Action for a Release from Petroleum Underground Storage Tanks, Volume 1

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    This study was undertaken to address the removal and closure of defective petroleum underground storage tanks in Kentucky: To address standards for levels of contamination requiring corrective action consistent with accepted scientific and technical principles. To recommend a matrix or scoring system to be used for (a) ranking sites as to actual or potential harm to human health and the environment caused by a release of petroleum from a petroleum storage tank, and (b) establishing standards and procedures for corrective action that shall adequately protect human health and the environment. To address all compounds individually and collectively known as petroleum. To produce a report that shall be scientifically defensible

    Kepler-16: A Transiting Circumbinary Planet

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    We report the detection of a planet whose orbit surrounds a pair of low-mass stars. Data from the Kepler spacecraft reveal transits of the planet across both stars, in addition to the mutual eclipses of the stars, giving precise constraints on the absolute dimensions of all three bodies. The planet is comparable to Saturn in mass and size, and is on a nearly circular 229-day orbit around its two parent stars. The eclipsing stars are 20% and 69% as massive as the sun, and have an eccentric 41-day orbit. The motions of all three bodies are confined to within 0.5 degree of a single plane, suggesting that the planet formed within a circumbinary disk.Comment: Science, in press; for supplemental material see http://www.sciencemag.org/content/suppl/2011/09/14/333.6049.1602.DC1/1210923.Doyle.SOM.pd

    Whole Genome Characterization of the Mechanisms of Daptomycin Resistance in Clinical and Laboratory Derived Isolates of Staphylococcus aureus

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    Background: Daptomycin remains one of our last-line anti-staphylococcal agents. This study aims to characterize the genetic evolution to daptomycin resistance in S. aureus. Methods: Whole genome sequencing was performed on a unique collection of isogenic, clinical (21 strains) and laboratory (12 strains) derived strains that had been exposed to daptomycin and developed daptomycin-nonsusceptibility. Electron microscopy (EM) and lipid membrane studies were performed on selected isolates. Results: On average, six coding region mutations were observed across the genome in the clinical daptomycin exposed strains, whereas only two mutations on average were seen in the laboratory exposed pairs. All daptomycin-nonsusceptible strains had a mutation in a phospholipid biosynthesis gene. This included mutations in the previously described mprF gene, but also in other phospholipid biosynthesis genes, including cardiolipin synthase (cls2) and CDP-diacylglycerol-glycerol-3-phosphate 3-phosphatidyltransferase (pgsA). EM and lipid membrane composition analyses on two clinical pairs showed that the daptomycin-nonsusceptible strains had a thicker cell wall and an increase in membrane lysyl-phosphatidylglycerol. Conclusion: Point mutations in genes coding for membrane phospholipids are associated with the development of reduced susceptibility to daptomycin in S. aureus. Mutations in cls2 and pgsA appear to be new genetic mechanisms affecting daptomycin susceptibility in S. aureus
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