3,209 research outputs found

    Operational alignment and calibration of the ISU for phase 2 of the V/STOL program. Volume 2 - Alignment

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    Strapdown inertia system for V/STOL program with theoretical error analysis using Kalman filter estimation theory and computer simulatio

    Arkansas Cotton Variety Test 1999

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    The primary aim of the Arkansas Cotton Variety Test is to provide unbiased data regarding the agronomic performance of cotton varieties in the major cotton growing areas in Arkansas. This information helps seed dealers establish marketing strategies and assists producers in choosing varieties to plant. In this way the annual test facilitates the inclusion of new, improved genetic material into Arkansas cotton production. The 1999 test had 67 entries (including 25 transgenic genotypes and 35 first-year entries), which were evaluated at sixsites in eastern Arkansas. The presence of four transgenic and five first-year entries among the top 10 yielding entries suggests that improvement is being accomplished in varietal development. This report also includes the Mississippi County Variety Test (an on-farm evaluation of selected varieties) and on-farm variety trials conducted by the Cooperative Extension Service

    Associations between gastro-oesophageal reflux, its management and exacerbations of chronic obstructive pulmonary disease

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    To determine factors, overall and by sex, associated with self-reported gastro-oesophageal reflux disease (GORD) in chronic obstructive pulmonary disease (COPD) patients, and to evaluate relationships between GORD, its modification by acid suppression medications (Proton Pump Inhibitors [PPI]/histamine-2 receptor antagonists [H2RA]) and exacerbations of COPD and mortality

    Atlas of Wetlands in the Principal Coal Surface Mining Region of Western Kentucky

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    This atlas contains maps of wetlands and surface mining activity in the Western Kentucky Coal Field, and focuses on a 3960 km2 (1530 mi2) region where approximately 90 percent of surface mining in the Coal field occures. Some present and potential competition exists between surface coal mining and wetland protection. A wetland classification, based on the recent FWS classification, includes six types of palustrine systems and one each of riverine and laucstrine systems. Wetlands and surface mines are located on twenty-seven 7.5 minute USGS quadrangles that define the study region. A total of 460 km2 (177 mi2) of wetlands are identified. Approximately 84 percent are broad-leaved deciduous forested wetlands, mostly as periodically-flooded riparian hardwood forests along broad alluvial bottom-lands. Also, several significant persistent emergent wetlands, shrub-scrub wetlands, and needle-leaved deciduous forested wetlands (bald cypress swamps) are identified in the study region. Summaries of geology and coal mining, hydrology, water quality, wetland vegetation and unique fish and wildlife species are presented for each quadrangle. Effects of existing and potential future surface mining of coal on wetland structure, function, and value are discussed. Species lists for vegetation and fish and wildlife and recent water quality data for the study region are given in the Appendices

    Last days in the old radiation laboratory (ORL), Berkeley, California, 1954

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    Govindjee, the founding editor of the Historical Corner of Photosynthesis Research, invited me 3 years ago to tell the story of why I left Melvin Calvin’s laboratory in the mid 1950s long before the 1961 Nobel Prize in Chemistry was awarded to Calvin for the path of carbon in photosynthesis. I have already written my scientific perspective on this topic (see Benson (Photosynth Res 73:29–49, 2002); also see Bassham (Photosynth Res 76:35–52, 2003) as he was also a major player in this research). Here, I present my recollections of my last days in the old radiation laboratory (ORL) at Berkeley, California. References have been added by Govindjee for the benefit of the readers

    Skyrmion Multi-Walls

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    Skyrmion walls are topologically-nontrivial solutions of the Skyrme system which are periodic in two spatial directions. We report numerical investigations which show that solutions representing parallel multi-walls exist. The most stable configuration is that of the square NN-wall, which in the N→∞N\to\infty limit becomes the cubically-symmetric Skyrme crystal. There is also a solution resembling parallel hexagonal walls, but this is less stable.Comment: 7 pages, 1 figur

    First Results from the CHARA Array. II. A Description of the Instrument

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    The CHARA Array is a six 1-m telescope optical/IR interferometric array located on Mount Wilson California, designed and built by the Center for High Angular Resolution Astronomy of Georgia State University. In this paper we describe the main elements of the Array hardware and software control systems as well as the data reduction methods currently being used. Our plans for upgrades in the near future are also described

    Microbiome profiling by Illumina sequencing of combinatorial sequence-tagged PCR products

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    We developed a low-cost, high-throughput microbiome profiling method that uses combinatorial sequence tags attached to PCR primers that amplify the rRNA V6 region. Amplified PCR products are sequenced using an Illumina paired-end protocol to generate millions of overlapping reads. Combinatorial sequence tagging can be used to examine hundreds of samples with far fewer primers than is required when sequence tags are incorporated at only a single end. The number of reads generated permitted saturating or near-saturating analysis of samples of the vaginal microbiome. The large number of reads al- lowed an in-depth analysis of errors, and we found that PCR-induced errors composed the vast majority of non-organism derived species variants, an ob- servation that has significant implications for sequence clustering of similar high-throughput data. We show that the short reads are sufficient to assign organisms to the genus or species level in most cases. We suggest that this method will be useful for the deep sequencing of any short nucleotide region that is taxonomically informative; these include the V3, V5 regions of the bac- terial 16S rRNA genes and the eukaryotic V9 region that is gaining popularity for sampling protist diversity.Comment: 28 pages, 13 figure

    Helioseismic Holography of an Artificial Submerged Sound Speed Perturbation and Implications for the Detection of Pre-Emergence Signatures of Active Regions

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    We use a publicly available numerical wave-propagation simulation of Hartlep et al. 2011 to test the ability of helioseismic holography to detect signatures of a compact, fully submerged, 5% sound-speed perturbation placed at a depth of 50 Mm within a solar model. We find that helioseismic holography as employed in a nominal "lateral-vantage" or "deep-focus" geometry employing quadrants of an annular pupil is capable of detecting and characterizing the perturbation. A number of tests of the methodology, including the use of a plane-parallel approximation, the definition of travel-time shifts, the use of different phase-speed filters, and changes to the pupils, are also performed. It is found that travel-time shifts made using Gabor-wavelet fitting are essentially identical to those derived from the phase of the Fourier transform of the cross-covariance functions. The errors in travel-time shifts caused by the plane-parallel approximation can be minimized to less than a second for the depths and fields of view considered here. Based on the measured strength of the mean travel-time signal of the perturbation, no substantial improvement in sensitivity is produced by varying the analysis procedure from the nominal methodology in conformance with expectations. The measured travel-time shifts are essentially unchanged by varying the profile of the phase-speed filter or omitting the filter entirely. The method remains maximally sensitive when applied with pupils that are wide quadrants, as opposed to narrower quadrants or with pupils composed of smaller arcs. We discuss the significance of these results for the recent controversy regarding suspected pre-emergence signatures of active regions
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