1,027 research outputs found

    Method for acquiring, storing and analyzing crystal images

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    A system utilizing a digital computer for acquiring, storing and evaluating crystal images. The system includes a video camera (12) which produces a digital output signal representative of a crystal specimen positioned within its focal window (16). The digitized output from the camera (12) is then stored on data storage media (32) together with other parameters inputted by a technician and relevant to the crystal specimen. Preferably, the digitized images are stored on removable media (32) while the parameters for different crystal specimens are maintained in a database (40) with indices to the digitized optical images on the other data storage media (32). Computer software is then utilized to identify not only the presence and number of crystals and the edges of the crystal specimens from the optical image, but to also rate the crystal specimens by various parameters, such as edge straightness, polygon formation, aspect ratio, surface clarity, crystal cracks and other defects or lack thereof, and other parameters relevant to the quality of the crystals

    Genetic Polymorphism in Evolving Population

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    We present a model for evolving population which maintains genetic polymorphism. By introducing random mutation in the model population at a constant rate, we observe that the population does not become extinct but survives, keeping diversity in the gene pool under abrupt environmental changes. The model provides reasonable estimates for the proportions of polymorphic and heterozygous loci and for the mutation rate, as observed in nature

    Modeling, Simulation, and Experiments of Coating Growth on Nanofibers

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    This work is a comparison of modeling and simulation results with experiments for an integrated experimental/modeling investigation of a procedure to coat nanofibers and core-clad nanostructures with thin film materials using plasma enhanced physical vapor deposition. In the experimental effort, electrospun polymer nanofibers are coated with metallic materials under different operating conditions to observe changes in the coating morphology. The modeling effort focuses on linking simple models at the reactor level, nanofiber level and atomic level to form a comprehensive model. The comprehensive model leads to the definition of an evolution equation for the coating free surface around an isolated nanofiber. This evolution equation was previously derived and solved under conditions of a nearly circular coating, with a concentration field that was only radially dependent and that was independent of the location of the coating free surface. These assumptions permitted the development of analytical expressions for the concentration field. The present work does not impose the above-mentioned conditions and considers numerical simulations of the concentration field that couple with level set simulations of the evolution equation for the coating free surface. Further, the cases of coating an isolated fiber as well as a multiple fiber mat are considered. Simulation results are compared with experimental results as the reactor pressure and power, as well as the nanofiber mat porosity, are varied. (C) 2008 American Institute of Physics

    Porphyromonas gingivalis and Treponema denticola Mixed Microbial Infection in a Rat Model of Periodontal Disease

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    Porphyromonas gingivalis and Treponema denticola are periodontal pathogens that express virulence factors associated with the pathogenesis of periodontitis. In this paper we tested the hypothesis that P. gingivalis and T. denticola are synergistic in terms of virulence; using a model of mixed microbial infection in rats. Groups of rats were orally infected with either P. gingivalis or T. denticola or mixed microbial infections for 7 and 12 weeks. P. gingivalis genomic DNA was detected more frequently by PCR than T. denticola. Both bacteria induced significantly high IgG, IgG2b, IgG1, IgG2a antibody levels indicating a stimulation of Th1 and Th2 immune response. Radiographic and morphometric measurements demonstrated that rats infected with the mixed infection exhibited significantly more alveolar bone loss than shaminfected control rats. Histology revealed apical migration of junctional epithelium, rete ridge elongation, and crestal alveolar bone resorption; resembling periodontal disease lesion. These results showed that P. gingivalis and T. denticola exhibit no synergistic virulence in a rat model of periodontal disease

    Cirsium species show disparity in patterns of genetic variation at their range-edge, despite similar patterns of reproduction and isolation

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    Genetic variation was assessed across the UK geographical range of Cirsium acaule and Cirsium heterophyllum. A decline in genetic diversity and increase in population divergence approaching the range edge of these species was predicted based on parallel declines in population density and seed production reported seperately. Patterns were compared with UK populations of the widespread Cirsium arvense.Populations were sampled along a latitudinal transect in the UK and genetic variation assessed using microsatellite markers. Cirsium acaule shows strong isolation by distance, a significant decline in diversity and an increase in divergence among range-edge populations. Geographical structure is also evident in C. arvense, whereas no such patterns are seen in C.heterophyllum. There is a major disparity between patterns of genetic variation in C. acaule and C. heterophyllum despite very similar patterns in seed production and population isolation in these species. This suggests it may be misleading to make assumptions about the geographical structure of genetic variation within species based solely on the present-day reproduction and distribution of populations

    The Grizzly, October 28, 1996

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    Alice Parker Conducts College Choir • A Question on Diversity • Security Flash • New Curriculum for Comm. Arts • Opinions: More on the Gun Control Debate; The Debates of Nothingness; How Open Are You? Voting for Dole in \u2796; I\u27m Voting for Dennis Miller • Letters from Ireland • University of Pennsylvania Anthropologist to Speak on Maya and Aztecs • Spotlight: Karl Yergey • Plugging-In to the Benefits of E-mail • Looking for a few Good Dangerous Minds: Education Club Re-activates • Field Hockey Drops One To American • Women\u27s Soccer Nets First Conference Win • Volleyball Loses Two • Men\u27s Soccer Defeats Dickinson 2-0 • Kings Point Trips Up Ursinushttps://digitalcommons.ursinus.edu/grizzlynews/1389/thumbnail.jp

    Research Progress Reports: Fruit and Vegetable Processing and Technology Division, Department of Horticulture [1967]

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    Evaluation of snap bean varieties for processing / Wilbur A. Gould and William Hildebolt -- Evaluation of various grape cultivars for processing. I. Table wines ; Recommended fruit varieties for canning and freezing / J. F. Gallander -- Evaluation of tomato varieties for processing / W. A. Gould, J. R. Geisman, C. S. Parrott, J. H. McClelland and W. N. Brown -- The effect of different levels of sugar and acid on the quality of apple fruit juice blends / James Gallander and Harold Stammer -- Epidermal sloughing of snap beans as influenced by processing variables / William Hildebolt and W. A. Gould -- Effect of stannous chloride on the color of glass packed kraut / J. R. Geisman -- Proteins and enzymes in the apple fruit in relation to variety and maturation ; Proteins and enzymes in tomato fruits / Robert L. Clements -- Effect of food additives on quality of canned tomatoes / Wilbur A. Gould -- Effects of selective herbicides on the composition and quality of tomatoes / W. A. Gould, J. R. Geisman, E. K. Alban and John Deppen -- Trace levels of pesticide residues in agricultural commodities in marketing channels / W. A. Gould, J. R. Geisman, E. K. Alban, John Deppen, and P. van Pottlesberghe -- Removal of DDT residues by unit operations in preparing and processing spinach / J. R. Geisman, John Deppen and Benita Yao -- The use of chlorine dioxide in handling and holding mechanically harvested tomatoes / J. R. Geisman, Winston D. Bash, Edwin Schmidt, Jr., Linda Hamrick and W. A. Gould -- Effect of mechanical harvesting and handling of tomatoes on quality of canned tomatoes / Wilbur A. Gould, J. R. Geisman, Edwin Schmidt, Jr., John McClelland and W. N. Brow

    The Grizzly, February 17, 1997

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    Window Shopping Without the Glass • Ursinus Celebrates Diversity Week • Students Benefit from Internships • Study Abroad: They Don\u27t Call \u27Em Deadlines For Nothing • Campus Apathy on the Issue of Diversity • And the Spirit Moved Them • Caplan Addresses Ethical Issues • Dr. Scott Landis\u27 Resignation Announced • So This is What Security Does: Ursinus\u27 Security Log Returns • Opinion: Greek Speaks Out; Read This if you Think Pledging is Dumb; Come Catch a Square; Perspective from Scotland; Faces of Silence • Defend Yourself! • Keep the Tutorial Program Alive! • Wrestling Bears Win Conference Championship • Women\u27s Basketball Nets Three More Wins • Men\u27s Basketball Drops Two • Gymnasts Leap to Two More Winshttps://digitalcommons.ursinus.edu/grizzlynews/1397/thumbnail.jp
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