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  • Fish movement and assemblage dynamics in a Pacific Northwest riverscape

    Creator:
    Baxter, Colden V.
    Abstract:
    This study examined fish movements and assemblage dynamics in the Wenaha, Grande Ronde, Snake river system of northeast Oregon and southeast Washington. I investigated the role of fish movement in the dynamics of stream fish assemblages and evaluated relationships between species movement, assemblage structure, and the heterogeneity of habitat at...
    Resource Type:
    Dissertation

  • Sex determination in Nile tilapia, Oreochromis niloticus: gene expression, masculinization methods, and environmental effects

    Creator:
    Sánchez, Wilfrido M. Contreras
    Abstract:
    Sex differentiation in fish is a labile process that allows sex inversion in several species. The inherent capacity of fish germ cells to differentiate into oocytes or spermatocytes constitutes a key factor allowing for functional sex inversion. This thesis set out to determine the mechanism involved in steroid-induced sex differentiation...
    Resource Type:
    Dissertation
    Full Text:
    unconditional support and continuous advice during the course of this research. Bob Mason, Barbara Shields and

  • Seasonal floodplain wetlands as fish habitat in Oregon and Washington

    Creator:
    Baker, Cynthia F.
    Abstract:
    To begin to understand freshwater seasonal floodplain fish communities in the context of human alteration of the physical system, species introductions and wetland restoration efforts, I studied fish assemblages in fifteen seasonal floodplain wetlands within four geographic regions (coastal, upper Columbia River estuary, Puget Sound and eastern Oregon/Washington) in the...
    Resource Type:
    Dissertation
    Full Text:
    Logan Scherrer, Paul Turenne, Dr. Barbara Shields and Michael Woffendin. I thank my advisors Drs

  • Integrative risk analysis of vector-borne disease

    Creator:
    Orme Zavaleta, Jennifer
    Abstract:
    In this dissertation I explore the application of two novel modeling techniques for improving risk analysis of vector-borne disease and discuss their potential use in integrating environmental risk assessment that guides environmental and public health decisions. Techniques for analyzing risk have been considered inadequate due to a lack of understanding...
    Resource Type:
    Dissertation
    Full Text:
    , Thomas Savage and Barbara Shields for their guidance and support as members of my graduate committee. I

  • The Oregon Coastal Subprovince, a new biogeographic subprovince for primary freshwater fishes in Oregon

    Creator:
    Kettratad, Jes
    Abstract:
    The Pacific Northwest has a relatively low diversity of primary freshwater fishes with most of the endemism and diversity in the Columbia River and Klamath River. However, the Oregon Coastal Subprovince defined as the coastal rivers from Miami River in the north to Sixes River in the south, has a...
    Resource Type:
    Dissertation
    Full Text:
    manuscript and serving on my committee. I thank Dr. Barbara Shields for all the moral support and

  • Chronobiology of garter snakes : environmental and hormonal mechanisms mediating hibernation and reproduction

    Creator:
    Lutterschmidt, Deborah I.
    Abstract:
    Most vertebrates exhibit seasonality in many life history traits. Such seasonal rhythms are temporally organized via the transduction of environmental cues (e.g., photoperiod, temperature) into appropriate endocrine signals. However, among ectothermic vertebrates that undergo continuous winter dormancy, temperature is the only environmental cue available for synchronizing seasonal rhythms. Most intriguing...
    Resource Type:
    Dissertation
    Full Text:
    , Carl B. Schreck, and Barbara A. Shields – for their academic support and contributions to my