3,688 research outputs found

    THE DISTRIBUTION OF BENEFITS RESULTING FROM BIOTECHNOLOGY ADOPTION

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    The purposes of this study are two-fold: (1) to estimate the size of total benefits arising from the adoption of agricultural biotechnology, and (2) to measure the distribution of total benefits among key stakeholders along the production and marketing chain, including U.S. farmers, gene developers, germplasm suppliers, U.S. consumers, and the producers and consumers in the rest of the world. This study focuses on the benefits that resulted from the adoption of herbicide-tolerant soybeans as well as insect-resistant (Bt) and herbicide-tolerant cotton in 1997. In this analysis, various data sources are examined for measuring the farm-level effects of adopting biotechnology and the resulting benefit estimates are compared. The size and distribution of the benefits arising from the adoption of biotech crops vary significantly, depending on the farm-level effects obtained from the various data sources and the supply and demand elasticity assumptions for the domestic and world markets. Estimates of the benefits derived from farm-level impacts that isolate the effects biotechnology appear to be the most plauible. This study does not lend support to the popular belief that U.S. farmers received at least one-half, or as much as two-thirds, of the total benefits realized from the adoption of biotechnology. In contrast, the results of this study indicate that in 1997, U.S. farmers realized considerably less than half of the total benefits. The bulk of the benefits appear to have gone to the gene supplier, seed companies, U.S. consumers, and the rest of the world.Research and Development/Tech Change/Emerging Technologies,

    William Arbuthnot Lane (1856-1943): Surgical Innovator and His Theory of Autointoxication.

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    William Arbuthnot Lane contributed to the advancement of many fields of orthopedics, otolaryngology, and general surgery. He is credited for his no-touch technique and the invention of long-handled instruments, some of which are still in use today, to minimize tissue handling. He is most well known for his hypothesis that slowing of gastric contents could cause a variety of ailments and this became known as Lane\u27s disease. Although his surgical treatment of Lane\u27s disease is now defunct, it advanced the surgical technique in colorectal surgery. It seems likely that some of Lane\u27s autointoxication patients would be classified today as patients with colonic inertia, diverticulitis, colonic volvulus, and megacolon or, which are all treated with colectomy. Lane was a pioneer in multiple fields and a true general surgeon. He advanced colorectal surgery immensely and propelled the field of surgery into a new era

    The periodic standing-wave approximation: eigenspectral computations for linear gravity and nonlinear toy models

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    The periodic standing wave approach to binary inspiral assumes rigid rotation of gravitational fields and hence helically symmetric solutions. To exploit the symmetry, numerical computations must solve for ``helical scalars,'' fields that are functions only of corotating coordinates, the labels on the helical Killing trajectories. Here we present the formalism for describing linearized general relativity in terms of helical scalars and we present solutions to the mixed partial differential equations of the linearized gravity problem (and to a toy nonlinear problem) using the adapted coordinates and numerical techniques previously developed for scalar periodic standing wave computations. We argue that the formalism developed may suffice for periodic standing wave computations for post-Minkowskian computations and for full general relativity.Comment: 21 pages, 10 figures, RevTe

    The periodic standing-wave approximation: post-Minkowski computation

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    The periodic standing wave method studies circular orbits of compact objects coupled to helically symmetric standing wave gravitational fields. From this solution an approximation is extracted for the strong field, slowly inspiralling motion of black holes and binary stars. Previous work on this model has dealt with nonlinear scalar models, and with linearized general relativity. Here we present the results of the method for the post-Minkowski (PM) approximation to general relativity, the first step beyond linearized gravity. We compute the PM approximation in two ways: first, via the standard approach of computing linearized gravitational fields and constructing from them quadratic driving sources for second-order fields, and second, by solving the second-order equations as an ``exact'' nonlinear system. The results of these computations have two distinct applications: (i) The computational infrastructure for the ``exact'' PM solution will be directly applicable to full general relativity. (ii) The results will allow us to begin supplying initial data to collaborators running general relativistic evolution codes.Comment: 19 pages, 3 figures, 1 table, RevTe

    The Periodic Standing-Wave Approximation: Overview and Three Dimensional Scalar Models

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    The periodic standing-wave method for binary inspiral computes the exact numerical solution for periodic binary motion with standing gravitational waves, and uses it as an approximation to slow binary inspiral with outgoing waves. Important features of this method presented here are: (i) the mathematical nature of the ``mixed'' partial differential equations to be solved, (ii) the meaning of standing waves in the method, (iii) computational difficulties, and (iv) the ``effective linearity'' that ultimately justifies the approximation. The method is applied to three dimensional nonlinear scalar model problems, and the numerical results are used to demonstrate extraction of the outgoing solution from the standing-wave solution, and the role of effective linearity.Comment: 13 pages RevTeX, 5 figures. New version. A revised form of the nonlinearity produces better result

    Supervoid Origin of the Cold Spot in the Cosmic Microwave Background

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    We use a WISE-2MASS-Pan-STARRS1 galaxy catalog to search for a supervoid in the direction of the Cosmic Microwave Background Cold Spot. We obtain photometric redshifts using our multicolor data set to create a tomographic map of the galaxy distribution. The radial density profile centred on the Cold Spot shows a large low density region, extending over 10's of degrees. Motivated by previous Cosmic Microwave Background results, we test for underdensities within two angular radii, 55^\circ, and 1515^\circ. Our data, combined with an earlier measurement by Granett et al 2010, are consistent with a large Rvoid=(192±15)h1MpcR_{\rm void}=(192 \pm 15)h^{-1} Mpc (2σ)(2\sigma) supervoid with δ0.13±0.03\delta \simeq -0.13 \pm 0.03 centered at z=0.22±0.01z=0.22\pm0.01. Such a supervoid, constituting a 3.5σ\sim3.5 \sigma fluctuation in the ΛCDM\Lambda CDM model, is a plausible cause for the Cold Spot.Comment: 4 pages, 2 figures, Proceedings of IAU 306 Symposium: Statistical Challenges in 21st Century Cosmolog

    Molecular Predictors of Anakinra Treatment Success in Heart Failure Patients with Reduced Ejection Fraction

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    Background. Kineret (Anakinra) is an interleukin-1 antagonist that is under investigation for its novel clinical application treating patients that have heart failure with reduced (\u3c50%) ejection fraction (HFrEF). A prior study from our group indicated that Anakinra may restore heart function by addressing dysregulations in HFrEF metabolic pathways. Herein, we attempt to elicit Anakinra’s effects on both metabolome and lipidome. Methods. Lipids and metabolites that had previously been quantified by mass spectrometry (MS) from patients (n=49) who had ≥2 mg/L of high-sensitivity C-reactive protein (hs-CRP) were mTIC normalized and transformed. We conducted a stepwise Linear Discriminant Analysis (r- LDA) to test Anakinra (2 and 12 weeks) vs placebo for separation from combined baseline. Metabolic pathway analysis was performed with Fisher’s exact test algorithm for detection of over-represented and enriched analytes. Univariate analysis (one tailed t-test p\u3c0.05) compared placebo and Anakinra after 12-weeks for effect(s). Metaboanalyst 4.0, JMP Pro 14.0, and a proprietary package in R (version 3.4.4) were the software for all analyses and data wrangling. Results. Analytes such as acylcarnitines C10:0 and C16:0 and hsCRP showed significant improvements after 12 weeks of Anakinra, leading to improved mitochondrial function, reduced inflammation, and overall better health outcomes. Statistically significant (p\u3c0.05) pathways including the citrate cycle, cysteine and methionine metabolism, galactose metabolism among others were associated with treatment. Conclusions. We were able to determine significant alterations to metabolomic and lipidomic concentrations after 12 weeks of Anakinra therapy. Our biochemical analyses verifies that Anakinra did improve heart function within our HFrEF pilot cohort.https://scholarscompass.vcu.edu/gradposters/1081/thumbnail.jp

    The Radio Sky at Meter Wavelengths: m-Mode Analysis Imaging with the Owens Valley Long Wavelength Array

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    A host of new low-frequency radio telescopes seek to measure the 21-cm transition of neutral hydrogen from the early universe. These telescopes have the potential to directly probe star and galaxy formation at redshifts 20z720 \gtrsim z \gtrsim 7, but are limited by the dynamic range they can achieve against foreground sources of low-frequency radio emission. Consequently, there is a growing demand for modern, high-fidelity maps of the sky at frequencies below 200 MHz for use in foreground modeling and removal. We describe a new widefield imaging technique for drift-scanning interferometers, Tikhonov-regularized mm-mode analysis imaging. This technique constructs images of the entire sky in a single synthesis imaging step with exact treatment of widefield effects. We describe how the CLEAN algorithm can be adapted to deconvolve maps generated by mm-mode analysis imaging. We demonstrate Tikhonov-regularized mm-mode analysis imaging using the Owens Valley Long Wavelength Array (OVRO-LWA) by generating 8 new maps of the sky north of δ=30\delta=-30^\circ with 15 arcmin angular resolution, at frequencies evenly spaced between 36.528 MHz and 73.152 MHz, and \sim800 mJy/beam thermal noise. These maps are a 10-fold improvement in angular resolution over existing full-sky maps at comparable frequencies, which have angular resolutions 2\ge 2^\circ. Each map is constructed exclusively from interferometric observations and does not represent the globally averaged sky brightness. Future improvements will incorporate total power radiometry, improved thermal noise, and improved angular resolution -- due to the planned expansion of the OVRO-LWA to 2.6 km baselines. These maps serve as a first step on the path to the use of more sophisticated foreground filters in 21-cm cosmology incorporating the measured angular and frequency structure of all foreground contaminants.Comment: 27 pages, 18 figure

    No Massive Companion to the Coherent Radio-Emitting M Dwarf GJ 1151

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    The recent detection of circularly polarized, long-duration (>8 hr) low-frequency (~150 MHz) radio emission from the M4.5 dwarf GJ 1151 has been interpreted as arising from a star-planet interaction via the electron cyclotron maser instability. The existence or parameters of the proposed planets have not been determined. Using 20 new HARPS-N observations, we put 99th-percentile upper limits on the mass of any close companion to GJ 1151 at Msini < 5.6 M earth. With no stellar, brown dwarf, or giant planet companion likely in a close orbit, our data are consistent with detected radio emission emerging from a magnetic interaction between a short-period terrestrial-mass planet and GJ 1151
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