317 research outputs found

    A Study of the Microstructural Evolution and Static Recrystallization of Magnesium Alloy AZ-31

    Get PDF
    The present study focuses on the evolving microstructure of Mg alloy AZ31. The material is subjected to channel die compression at room temperature to simulate a reduction stage in the rolling process. Samples are annealed to provoke recovery, static recrystallization, and grain growth. Annealing is carried out at three temperatures for times ranging from 10s to 10,000s. The material’s response is exhibited through the use of data collection methods such as microhardness, optical microscopy, and electron backscatter diffraction (EBSD). Methodology behind experimentation and data collection techniques are documented in detail. Conclusions are made about the effects of the compression and annealing processes on the material’s microstructure. The Johnson-Mehl-Avrami-Kolmogorov (JMAK) model is introduced, and a simple recrystallization kinetics plot is attempted

    SONiCS: PCR stutter noise correction in genome-scale microsatellites

    Full text link
    Motivation Massively parallel capture of short tandem repeats (STRs, or microsatellites) provides a strategy for population genomic and demographic analyses at high resolution with or without a reference genome. However, the high Polymerase Chain Reaction (PCR) cycle numbers needed for target capture experiments create genotyping noise through polymerase slippage known as PCR stutter. Results We developed SONiCS—Stutter mONte Carlo Simulation—a solution for stutter correction based on dense forward simulations of PCR and capture experimental conditions. To test SONiCS, we genotyped a 2499-marker STR panel in 22 humpback dolphins (Sousa sahulensis) using target capture, and generated capillary-based genotypes to validate five of these markers. In these 110 comparisons, SONiCS showed a 99.1% accuracy rate and a 98.2% genotyping success rate, miscalling a single allele in a marker with low sequence coverage and rejecting another as un-callable. Availability and implementation Source code and documentation for SONiCS is freely available at https://github.com/kzkedzierska/sonics. Raw read data used in experimental validation of SONiCS have been deposited in the Sequence Read Archive under accession number SRP135756

    Ancient Plant Genomics in Archaeology, Herbaria, and the Environment : Annual Review of Plant Biology

    Get PDF
    The ancient DNA revolution of the past 35 years has driven an explosion in the breadth, nuance, and diversity of questions that are approachable using ancient biomolecules, and plant research has been a constant, indispensable facet of these developments. Using archaeological, paleontological, and herbarium plant tissues, researchers have probed plant domestication and dispersal, plant evolution and ecology, paleoenvironmental composition and dynamics, and other topics across related disciplines. Here, we review the development of the ancient DNA discipline and the role of plant research in its progress and refinement. We summarize our understanding of long-term plant DNA preservation and the characteristics of degraded DNA. In addition, we discuss challenges in ancient DNA recovery and analysis and the laboratory and bioinformatic strategies used to mitigate them. Finally, we review recent applications of ancient plant genomic research

    Growing Up in Civil Rights Richmond: A Community Remembers

    Get PDF
    Published on the occasion of the exhibition Growing Up in Civil Rights Richmond: A Community Remembers, Joel and Lila Harnett Museum of Art, University of Richmond Museums, January 17 to May 10, 2019. Organized by the University of Richmond Museums, the exhibition was developed by Ashley Kistler, independent curator, and Laura Browder, Tyler and Alice Haynes Professor of American Studies, University of Richmond. The exhibition, related programs, and publication are made possible in part with funds from the Louis S. Booth Arts Fund and with support from the University’s Cultural Affairs Committee. The printed exhibition catalogue was made possible in part with support from the Elizabeth Firestone Graham Foundation. Published by University of Richmond Museums, Richmond, Virginia. Edited by N. Elizabeth Schlatter, University of Richmond Museums, and Ashley Kistler, independent curator. Designed by DELANO Creative, Richmond, Virginia Printed by Worth Higgins & Associates Inc., Richmond, Virginia. Cover: Brian Palmer (American, born 1964), Deborah Taylor, Franklin Military Academy (formerly East End High School), 2017, archival inkjet print on paper, 30 x 40 inches, lent courtesy of the artist.https://scholarship.richmond.edu/exhibition-catalogs/1006/thumbnail.jp

    A MEMS Photoacoustic Detector of Terahertz Radiation for Chemical Sensing

    Get PDF
    A piezoelectric Microelectromechanical system (MEMS) cantilever pressure sensor was designed, modeled, fabricated, and tested for sensing the photoacoustic response of gases to terahertz (THz) radiation. The sensing layers were comprised of three thin films; a lead zirconate titanate (PZT) piezoelectric layer sandwiched between two metal contact layers. The sensor materials were deposited on the silicon device layer of a silicon-on-insulator (SOI) wafer, which formed the physical structure of the cantilever. To release the cantilever, a hole was etched through the backside of the wafer and the buried oxide was removed with hydrofluoric acid. Devices were then tested in a custom made THz vacuum test chamber. Cantilever deflection was observed with a laser interferometer in the test chamber and preliminary data indicates the signals were caused by the photoacoustic effect. Future device data will also include the piezoelectric voltage signal analysis

    The Contribution of Fermi Gamma-Ray Pulsars to the local Flux of Cosmic-Ray Electrons and Positrons

    Full text link
    We analyze the contribution of gamma-ray pulsars from the first Fermi-Large Area Telescope (LAT) catalogue to the local flux of cosmic-ray electrons and positrons (e+e-). We present new distance estimates for all Fermi gamma-ray pulsars, based on the measured gamma-ray flux and pulse shape. We then estimate the contribution of gamma-ray pulsars to the local e+e- flux, in the context of a simple model for the pulsar e+e- emission. We find that 10 of the Fermi pulsars potentially contribute significantly to the measured e+e- flux in the energy range between 100 GeV and 1 TeV. Of the 10 pulsars, 2 are old EGRET gamma-ray pulsars, 2 pulsars were discovered with radio ephemerides, and 6 were discovered with the Fermi pulsar blind-search campaign. We argue that known radio pulsars fall in regions of parameter space where the e+e- contribution is predicted to be typically much smaller than from those regions where Fermi-LAT pulsars exist. However, comparing the Fermi gamma-ray flux sensitivity to the regions of pulsar parameter space where a significant e+e- contribution is predicted, we find that a few known radio pulsars that have not yet been detected by Fermi can also significantly contribute to the local e+e- flux if (i) they are closer than 2 kpc, and if (ii) they have a characteristic age on the order of one mega-year.Comment: 21 pages, 6 figures, accepted for publication in JCA

    The Grizzly, February 15, 1985

    Get PDF
    USGA Reschedules Election • Japanese Studies Prof. Returns to U.C. • UC Retention Rate Above National Average • Without Reform, Second Election Doomed to Failure • U.C. Contributes to Local Secondary Education: Need for Tutors May Grow • College Students Have Trouble Managing Money, Survey Shows • Campus Life Surveys Possible Displacements • Grapplers Keep Winning: Wiehler Notches 14-second Fall • Senior Matmen Get Last Shot at MAC Title • Ververeli Operates on the Mats for Now • Mers Dunk Dips • Mermaids Win Three, Lose One • UC Grad Writes Book • B-ball Drops Two • Lady Hoopsters\u27 Losing Ways Continuehttps://digitalcommons.ursinus.edu/grizzlynews/1133/thumbnail.jp

    Influenza A Virus H5–specific Antibodies in Mute Swans (\u3ci\u3eCygnus olor\u3c/i\u3e) in the USA

    Get PDF
    The use of serologic assays for influenza A virus (IAV) surveillance in wild birds has increased because of the availability of commercial enzyme-linked immunosorbent assays (ELISAs). Recently, an H5-specific blocking ELISA (bELISA) was shown to reliably detect H5-specific antibodies to low- and highpathogenic H5 viruses in experimentally infected waterfowl. Mute Swans (Cygnus olor) were frequently associated with highly pathogenic H5N1 outbreaks in Europe and may have a similar role if highly pathogenic H5N1 is introduced into North America. We measured the prevalence of antibodies to the nucleoprotein and H5 protein in Mute Swans using three serologic assays. We collected 340 serum samples from Mute Swans in Michigan, New Jersey, New York, and Rhode Island, US. We detected antibodies to the IAV nucleoprotein in 66.2% (225/340) of the samples. We detected H5-specific antibodies in 62.9% (214/340) and 18.8% (64/340) using a modified H5 bELISA protocol and hemagglutination inhibition (HI) assay, respectively. The modified H5 bELISA protocol detected significantly more positive samples than did the manufacturer’s protocol. We also tested 46 samples using virus neutralization. Neutralization results had high agreement with the modified H5 bELISA protocol and detected a higher prevalence than did the HI assay. These results indicate that North American Mute Swans have high nucleoprotein and H5 antibody prevalences
    • …
    corecore