179 research outputs found

    Lacustrine evidence for moisture changes in the Nebraska Sand Hills during Marine Isotope Stage 3

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    In the central Great Plains of North America, loess stratigraphy suggests that climate during the late Pleistocene was cold and dry. However, this record is discontinuous, and there are few other records of late-Pleistocene conditions. Cobb Basin, located on the northern edge of the Nebraska Sand Hills, contains lacustrine sediments deposited during Marine Isotope Stage 3, beginning approximately 45,000 cal yr BP and continuing for at least 10,000 yr. The lake was formed by a dune dam blockage on the ancient Niobrara River, and its deposits contain a diatom record that indicates changes through time in lake depth driven by changes in effective moisture. During the earliest stages of lake formation, the climate was arid enough to mobilize dunes and emplace dune sand into a blocking position within the Niobrara stream bed. Diatom assemblages suggest that lake-level was shallow at formation, increased substantially during a wet interval, and then became shallow again, as arid conditions resumed. By about 27,000 cal yr BP the lake was filled, and a shallow ephemeral river occupied the basin

    Lacustrine evidence for moisture changes in the Nebraska Sand Hills during Marine Isotope Stage 3

    Get PDF
    In the central Great Plains of North America, loess stratigraphy suggests that climate during the late Pleistocene was cold and dry. However, this record is discontinuous, and there are few other records of late-Pleistocene conditions. Cobb Basin, located on the northern edge of the Nebraska Sand Hills, contains lacustrine sediments deposited during Marine Isotope Stage 3, beginning approximately 45,000 cal yr BP and continuing for at least 10,000 yr. The lake was formed by a dune dam blockage on the ancient Niobrara River, and its deposits contain a diatom record that indicates changes through time in lake depth driven by changes in effective moisture. During the earliest stages of lake formation, the climate was arid enough to mobilize dunes and emplace dune sand into a blocking position within the Niobrara stream bed. Diatom assemblages suggest that lake-level was shallow at formation, increased substantially during a wet interval, and then became shallow again, as arid conditions resumed. By about 27,000 cal yr BP the lake was filled, and a shallow ephemeral river occupied the basin

    Distributed high-temperature pressure sensing using air-hole microstructural fibers

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    We present spatially resolved Rayleigh scattering measurements in different polarization-maintaining (PM) fibers for high-temperature pressure sensing. The pressure-induced birefringence in the fiber cores is interrogated using polarization-resolved frequency-swept interferometry. The pressure responses of a PM photonic crystal fiber and a twin-air-hole PM fiber are investigated for a pressure range of 0 to 13.8 MPa (0-2000 psi) at room temperature and at temperatures as high as 800 °C. The proposed sensing system provides, for the first time to our knowledge, a truly distributed pressure-sensing solution for high-temperature applications. © 2012 Optical Society of America

    Macrophage phenotype in response to ECM bioscaffolds

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    Macrophage presence and phenotype are critical determinants of the healing response following injury. Downregulation of the pro-inflammatory macrophage phenotype has been associated with the therapeutic use of bioscaffolds composed of extracellular matrix (ECM), but phenotypic characterization of macrophages has typically been limited to small number of non-specific cell surface markers or expressed proteins. The present study determined the response of both primary murine bone marrow derived macrophages (BMDM) and a transformed human mononuclear cell line (THP-1 cells) to degradation products of two different, commonly used ECM bioscaffolds; urinary bladder matrix (UBM-ECM) and small intestinal submucosa (SIS-ECM). Quantified cell responses included gene expression, protein expression, commonly used cell surface markers, and functional assays. Results showed that the phenotype elicited by ECM exposure (MECM) is distinct from both the classically activated IFNÎł + LPS phenotype and the alternatively activated IL-4 phenotype. Furthermore, the BMDM and THP-1 macrophages responded differently to identical stimuli, and UBM-ECM and SIS-ECM bioscaffolds induced similar, yet distinct phenotypic profiles. The results of this study not only characterized an MECM phenotype that has anti-inflammatory traits but also showed the risks and challenges of making conclusions about the role of macrophage mediated events without consideration of the source of macrophages and the limitations of individual cell markers

    1972 Research Progress Reports, Fruit and Vegetable Processing and Food Technology

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    Evaluation of tomato cultivars / W. A. Gould, James Black, Louise Howiler, Shirley Perryman, and Stanley Z. Berry -- Effects of food additives on the quality of canned tomatoes / Wilbur A. Gould, John Mount, Jacquelyn Gould, Louise Howiler, and James Black -- Effect of storage temperature on shelf life of ascorbic acid fortified tomato juice / Gerald A. Pope and Wilbur A. Gould -- Survey of waste disposal practices of Ohio tomato processors / J. R. Geisman -- Evaluation of snap bean varieties for processing / Wilbur A. Gould, Jacquelyn Gould and Roberta Topits -- The effect of variety, size, and fermentation temperature on the quality attributes of cucumber pickles / Gary Flinn and Wilbur A. Gould -- Progress report on frozen corn-on-the-cob / James W. Swinehart and Wilbur A. Gould -- Progress report on cabbage lipids / Andrew C. Peng -- Effect of soybean flour on quality and protein content in the manufacture of doughnuts / Mohamed I. Mahmoud and Wilbur A. Goul

    Production of (Uranium) Tetrafluoride

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    Production of tetrafluoride for the month of April was 49,400. New equipment installed late in March operated smoothly and the production was slightly over the rated capacity of the plant. Nickel ends were welded on to the steel reactor tubes to prevent corrosion at the cover joint and possible contamination of the product with iron. The nickel ends will also save considerable repair work on the tube ends. The magnesium trays for some of the reactors are beginning to crack at the sides from frequent straightening. The trays are bent out of shape by the expansion of the product and are reshaped by hammering over a die. Some of the cracks have been repaired by welding but this is not very satisfactory because the welded trays are harder to straighten and often crack again
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