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  • Natural enemies of native bumble bees (Hymenoptera: Apidae) in western Oregon

    Creator:
    Maxfield-Taylor, Sarah A.
    Abstract:
    Bumble bees (Hymenoptera: Apidae) are important native pollinators in wild and agricultural systems, and are one of the few groups of native bees commercially bred for use in the pollination of a range of crops. In recent years, declines in bumble bees have been reported globally. One factor implicated in...
    Resource Type:
    Masters Thesis
    Full Text:
    other graduate committee members, Dr. Bill Stephen and Dr. Ramesh Sagili, for your time and

  • Native bees, honeybees and pollination in Oregon cranberries

    Creator:
    McKenney, Melissa A.
    Abstract:
    Farmers rely almost exclusively on the imported European honeybee (Apis mellifera L.) for fruit and vegetable crop pollination services. The recent decline in honeybee health has underscored the danger of relying on a single species to provide vital services. Increasing pollinator biodiversity with native bees may provide biological insurance against...
    Resource Type:
    Honors College Thesis

  • Foraging in disturbed areas : a study of sweat bees (Hymenoptera: Halictidae) in Oregon

    Creator:
    Broussard, Melissa
    Abstract:
    Bees provide vital ecosystem services for cropping systems as well as natural landscapes. Declines in both both native bee and managed honey bee (Apis mellifera L.) populations has brought attention to the significance of their role as pollinators in managed and native ecosystems. As a result, conservation efforts have been...
    Resource Type:
    Masters Thesis

  • A systematic study of the genus Phytocoris Fallén (Heteroptera:Miridae) in western North America

    Creator:
    Stonedahl, Gary Michael
    Abstract:
    The western Nearctic species of the genus Phytocoris Fallen were taxonomically revised. Over 15,000 specimens were examined. Information concerning host plant associations and distributions was compiled and summarized for use by future researchers. External morphological features and characters of the male genitalia were used to distinguish species. The genital tubercles...
    Resource Type:
    Dissertation
    Full Text:
    . Kenton L. Chambers, Robert E. Frenkel, James D. Hall, and William P. Stephen, for their comments on the

  • Environmental impacts on native bumble bee pollinators in an agricultural landscape of western Oregon

    Creator:
    Skyrm, Kimberly M.
    Abstract:
    Bumble bees provide vital pollination services in both native and agricultural landscapes. However, in recent years, bumble bee populations have experienced global population declines. The primary causes of these declines have been attributed to the environmental impacts of pathogens, pesticide use and habitat fragmentation. While research has examined the impacts...
    Resource Type:
    Dissertation
    Full Text:
    , and writing of research in Chapter II-V. Dr. William P. Stephen assisted with study design, data

  • Current mode analog and digital circuit design

    Creator:
    Liang, Guojin
    Abstract:
    In this dissertation, two important current mode circuit design subjects have been explored. In the first part, the switched-current circuit technique has been investigated. The fundamental performance and limitations of this technique are explored. One of the major limitations, the signal distortion caused by clock feedthrough has been substantially reduced...
    Resource Type:
    Dissertation
    Full Text:
    graduate committee members, Prof. Donald Amort, Prof. James Herzog, Prof. Stephen Goodnick, and Prof

  • The ecology of the olive ridley turtle (Lepidochelys olivacea) in the eastern tropical Pacific Ocean during the breeding/nesting season

    Creator:
    Beavers, Sallie Christian
    Resource Type:
    Masters Thesis
    Full Text:
    . I thank the members of my committee, Drs. William G. Pearcy, W. Daniel Edge, Stephen B. Reilly, and

  • Monte Carlo simulations of magnetic semiconducting Superlattices

    Creator:
    Scott, Silas Menlo
    Abstract:
    Computer simulations invoking the Metropolis Algorithm and Monte Carlo techniques were constructed to model the behavior ofvarious systems of magnetic semiconductors. Among the systems modeled were bulk type II FCC antiferromagnets and simple cubic thin films and superlattices. Studies of bulk antiferromagnets revealed dependence of Neel Temperature on nearest neighbor...
    Resource Type:
    Dissertation
    Full Text:
    , Janet Tate, William Hetherington, and Stephen Giovannani for their time and assistance. Special thanks

  • Studies to improve lactic acid bacterial starter cultures

    Creator:
    Khosravi, Lewa
    Abstract:
    Three commercial sausage starter cultures were grown in an internal-pH-controlled medium (PHASE 4) and in a soluble phosphate-buffered medium. The cultures were tested by comparing viable counts before and after freezing at -40 C or freeze-drying and subsequent storage for 3 months in the frozen or dried state. Strains varied...
    Resource Type:
    Dissertation
    Full Text:
    . Stephen Kaattari, Prof. Floyd W. Bodyfelt, Dr. Donald E. Mattson , Dr. William C. Denison and Dr

  • Design, fabrication, and testing of inhomogeneous dielectrics

    Creator:
    Lim, Sungkyoo
    Abstract:
    In this thesis the concept of inhomogeneous dielectrics is demonstrated for various optical coating applications. Compositionally-varying silicon oxynitride (SiON) dielectric layers, with the refractive index varying as a function of position, are grown by computer-controlled plasma-enhanced chemical vapor deposition (PECVD) using silane, nitrogen, and nitrous oxide reactant gases. Compositionally graded...
    Resource Type:
    Dissertation
    Full Text:
    Professors Curtis R. Cook, Vijai K. Tripathi, Stephen M. Goodnick, and William Hetherington for serving on