503 research outputs found

    Soybean emergence, growth, and development following corn stover removal

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    Title from PDF of title page (University of Missouri--Columbia, viewed on May 30, 2013).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Thesis advisor: Dr. William J. WieboldIncludes bibliographical references.M.S. University of Missouri--Columbia 2012."May 2012"The Energy Independence and Security Act of 2007 mandates the use of 21 billion gallons of biofuel from cellulose or other advanced forms by the year 2022. Corn stover is an attractive choice for cellulosic ethanol production because it is readily available and easily obtainable. Understanding how corn stover removal affects soybean emergence and development is essential to developing appropriate management recommendations for both partners in a corn-soybean rotation. The objectives of this study were to (1) determine the effects of corn stover removal on soybean emergence and development and (2) to determine if cover crops ameliorate any of the possible negative effects to soybean from corn stover removal. Field experiments were conducted near Columbia, Missouri in 2010 and 2011. The effects of two residue removal treatments (Baled and Not Baled), three cover crop treatments (rye, radish, and no cover crop) and two emergence class treatments (Early emergence and Late emergence) were analyzed. Corn stover removal increased the mean daily average soil temperature, but the absence or presence of residue on the soil surface did not affect emergence. Emergence class had a significant effect on the number of days from planting to emergence at nearly every growth stage in both years. Removing residue increased stand density in both years. Residue removal affected seed number and seed weight per plant in both years. Grain weight per plant was significantly higher in the Early emergence class than in the Late emergence class. The results of this study suggest that corn stover can be removed and used for biofuel if residue removal does not exceed recommended rates, and if cover crops are used to replace removed residue

    Dust emission at 8-mic and 24-mic as Diagnostics of HII Region Radiative Transfer

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    We use the Spitzer SAGE survey of the Magellanic Clouds to evaluate the relationship between the 8-mic PAH emission, 24-mic hot dust emission, and HII region radiative transfer. We confirm that in the higher-metallicity Large Magellanic Cloud, PAH destruction is sensitive to optically thin conditions in the nebular Lyman continuum: objects identified as optically thin candidates based on nebular ionization structure show 6 times lower median 8-mic surface brightness (0.18 mJy arcsec^-2) than their optically thick counterparts (1.2 mJy arcsec^-2). The 24-mic surface brightness also shows a factor of 3 offset between the two classes of objects (0.13 vs 0.44 mJy arcsec^-2, respectively), which is driven by the association between the very small dust grains and higher density gas found at higher nebular optical depths. In contrast, PAH and dust formation in the low-metallicity Small Magellanic Cloud is strongly inhibited such that we find no variation in either 8-mic or 24-mic emission between our optically thick and thin samples. This is attributable to extremely low PAH and dust production together with high, corrosive UV photon fluxes in this low-metallicity environment. The dust mass surface densities and gas-to-dust ratios determined from dust maps using Herschel HERITAGE survey data support this interpretation.Comment: Accepted to ApJ, May 15, 2017. 10 pages, 9 figure

    Effectiveness of interventions to support the early detection of skin cancer through skin self-examination: a systematic review and meta-analysis.

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    BACKGROUND: As skin cancer incidence rises, there is a need to evaluate early detection interventions by the public using skin self-examination (SSE); however, the literature focuses on primary prevention. No systematic reviews have evaluated the effectiveness of such SSE interventions. OBJECTIVES: To systematically examine, map, appraise and synthesize, qualitatively and quantitatively, studies evaluating the early detection of skin cancer, using SSE interventions. METHODS: This is a systematic review (narrative synthesis and meta-analysis) examining randomized controlled trials (RCTs) and quasiexperimental, observational and qualitative studies, published in English, using PRISMA and National Institute for Health and Care Excellence guidance. The MEDLINE, Embase and PsycINFO databases were searched through to April 2015 (updated in April 2018 using MEDLINE). Risk-of-bias assessment was conducted. RESULTS: Included studies (n = 18), totalling 6836 participants, were derived from 22 papers; these included 12 RCTs and five quasiexperiments and one complex-intervention development. More studies (n = 10) focused on targeting high-risk groups (surveillance) than those at no higher risk (screening) (n = 8). Ten (45%) study interventions were theoretically underpinned. All of the study outcomes were self-reported, behaviour related and nonclinical in nature. Meta-analysis demonstrated the impact of the intervention on the degree of SSE activity from five studies, especially in the short term (up to 4 months) (odds ratio 2·31, 95% confidence interval 1·90-2·82), but with small effect sizes. Risk-of-bias assessment indicated that 61% of the studies (n = 11) were of weak quality. CONCLUSIONS: Four RCTs and a quasiexperimental study indicate that some interventions can enhance SSE activity and so are more likely to aid early detection of skin cancer. However, the actual clinical impact remains unclear, and this is based on overall weak study (evidence) quality

    Electron-Like Fermi Surface and Remnant (pi,0) Feature in Overdoped La1.78Sr0.22CuO4

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    We have performed an angle-resolved photoemission study of overdoped La1.78Sr0.22CuO4, and have observed sharp nodal quasiparticle peaks in the second Brillouin zone that are comparable to data from Bi2Sr2CaCu2O8+d. The data analysis using energy distribution curves, momentum distribution curves and intensity maps all show evidence of an electron-like Fermi surface, which is well explained by band structure calculations. Evidence for many-body effects are also found in the substantial spectral weight remaining below the Fermi level around (pi,0), where the band is predicted to lie above EF.Comment: 4 pages, 4 figure

    Methods for biological, chemical, and physical analyses in reservoirs

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    This manual contains detailed descriptions of biological, chemical and physical sampling and analytical procedures used at the Lake Mead Limnological Research Center. The manual was prepared in response to requests made by numerous individuals involved in the Las Vegas Valley Water Quality Program. This manual represents what we consider to be a reasonably complete compilation of methods useful in studying both general and specific limnological questions. While each section is sufficiently detailed to be of use to investigators with little experience in limnological methodology, the methods can be used on a wide variety of lakes and reservoirs, with relatively little modification

    Stick or grip? Co-evolution of adhesive toepads and claws in Anolis lizards

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    Exploring the relationship between phenotype and performance in an ecological and evolutionary context is crucial to understand the adaptive nature of phenotypic traits. Despite their ubiquity in vertebrates, few studies have examined the functional and ecological significance of claw morphologies. Here we examine the adhesive toepad and claw system of Anolis lizards. Claw characters are significantly different between lizards classified as arboreal (perch height > 1 m)and non-­‐arboreal (perch height < 1 m). Arboreal species possess significantly higher and longer claws, and show trends toward decreased claw curvature and wider claw tip angles. Toepad size and claw length and height are tightly correlated with each other and with perch height, suggesting that the adhesive toepad and gripping claw have co-­‐evolved to accommodate different habitats. The functional morphology and evolution of claws are ripe areas for future investigation.Organismic and Evolutionary Biolog

    3-\u3ci\u3eO\u3c/i\u3e sulfation of heparin leads to hepatotropism and longer circulatory half-life

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    Introduction: Heparins are common blood anticoagulants that are critical for many surgical and biomedical procedures used in modern medicine. In contrast to natural heparin derived from porcine gut mucosa, synthetic heparins are homogenous by mass, polymer length, and chemistry. Materials & methods: Stable cell lines expressing the human and mouse Stabilin receptors were used to evaluate endocytosis of natural and synthetic heparin. We chemoenzymatically produced synthetic heparin consisting of 12 sugars (dodecamers) containing 14 sulfate groups resulting in a non-3-O sulfated structure (n12mer). Half of the n12mer was modified with a 3-O sulfate on a single GlcNS sugar producing the 3-O sulfated heparin (12mer). Wildtype (WT), Stabilin-1 knock-out (KO), and Stabilin-2 KO C57BL/6 mice were developed and used for metabolic studies and provided as a source for primary liver sinusoidal endothelial cells. Results & conclusions: Human and mouse Stabilin-2 receptors had very similar endocytosis rates of both the 12mer and n12mer, suggesting that they are functionally similar in primary cells. Subcutaneous injections of the n12mer and 12mer revealed that the 12mer had a much longer half-life in circulation and a higher accumulation in liver. The n12mer never accumulated in circulation and was readily excreted by the kidneys before liver accumulation could occur. Liver sinusoidal endothelial cells from the Stabilin-2 KO mice had lower uptake rates for both dodecamers, whereas, the Stabilin-1 KO mice had lower endocytosis rates for the 12mer than the n12mer. 3-O sulfation of heparin is correlated to both a longer circulatory half-life and hepatotropism which is largely performed by the Stabilin receptors

    Prototypicality norms for 28 semantic categories

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