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Filtering by: Creator Sherr, Evelyn Remove constraint Creator: Sherr, Evelyn Resource Type Masters Thesis Remove constraint Resource Type: Masters Thesis

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  • Investigating the ecological role of cell signaling in free-living marine heterotrophic protists

    Creator:
    Hartz, Aaron J.
    Abstract:
    Phagotrophic protists are major consumers of microbial biomass in aquatic ecosystems. However, biochemical mechanisms underlying prey recognition and phagocytosis by protists are not well understood. We investigated the potential roles of cell signaling mechanisms in chemosensory response to prey, and in capture of prey cells, by a marine ciliate (Uronema...
    Resource Type:
    Masters Thesis
    Full Text:
    ,
Barry
Sherr,
Evelyn
Sherr,
Rick
Colwell,
Theresa
 Filtz,
and
Mario
Magaña.


I
would
also
like
to
thank

  • Distribution and abundance of coastal fish and macro-invertebrates in the Galapagos Islands

    Creator:
    Figueroa, Diego
    Abstract:
    The Galapagos Islands, located off the coast of Ecuador, have a spatially diverse marine environment suitable for a variety of species with different climatic requirements. A year-long inventory program was carried out in 2000-2001 to provide baseline data on the abundances and distribution of coastal fish and macro-invertebrates. The purposes...
    Resource Type:
    Masters Thesis
    Full Text:
    , Evelyn Sherr and Mary Santelmann for their advice and encouragement throughout my graduate studies. I

  • Phosphorus control of nitrogen fixation

    Creator:
    Watkins-Brandt, Katie S.
    Abstract:
    Under conditions of fixed N-limitation, as with most oligotrophic systems, the process of biological N₂ fixation (diazotrophy) is favored, provided the necessary trace elements and vitamins are sufficient. Despite the well understood contributions of N₂ fixation in oligotrophic regions, the nutritional and ecological controls of marine diazotrophs have not been...
    Resource Type:
    Masters Thesis
    Full Text:
    supporting my research and providing the means necessary for an excellent experience. Dr. Evelyn Sherr

  • Production and partitioning of organic matter during simulated phytoplankton blooms

    Creator:
    Wetz, Michael S.
    Abstract:
    Few studies have examined the partitioning of organic matter in upwelling systems, despite the fact that these systems play a key role in carbon and nitrogen budgets in the ocean. We examined the production and partitioning of phytoplankton-derived organic matter in deck incubations off Oregon during the upwelling season. During...
    Resource Type:
    Masters Thesis
    Full Text:
    also thank my committee members, Ricardo Letelier, Evelyn Sherr, and Fred Prahl, for their willingness

  • The biology of a shallow-water methane vent

    Creator:
    Juhl, Andrew R.
    Abstract:
    In September of 1989, the site of an active seafloor methane vent was confirmed approximately 20 km off the coast of Oregon in shelf waters 135 m deep. The location of the vent had been described to Oregon State University oceanographers by a local commercial fisherman. Preliminary observations in 1989...
    Resource Type:
    Masters Thesis
    Full Text:
    advisor as I've had. I'd also like to thank the other members of my committee, Evelyn Sherr, Bruce Menge

  • Design, assessment, and future implications of the Multiple Enzyme Analyzer (MEA), a tool for in-situ monitoring of marine microbial activity

    Creator:
    Jaeger, Stephanie A.
    Abstract:
    The microbial loop plays a crucial role in remineralization of organic matter and fuels recycled production in the aquatic environment. The capability of microbes to utilize particular compounds can be examined through their ectoenzyme (found outside the cell) activities using fluorogenic substrate analogs. These catalysts hydrolyze polymers otherwise too large...
    Resource Type:
    Masters Thesis
    Full Text:
    would also like to thank my committee members, Dr. Evelyn Sherr and Dr. Fredrick Prahl, for their

  • Effects of fire on seedling establishment in upland prairies in the Willamette Valley, Oregon

    Creator:
    Maret, Mary P.
    Abstract:
    Prior to European settlement, native prairie dominated the landscape of the Willamette Valley. Today, due to urbanization, agriculture, and the cessation of burning, only isolated remnants of these grasslands still exist. In response to conservation concerns, there has been a move to restore the remaining prairies in the Willamette Valley,...
    Resource Type:
    Masters Thesis
    Full Text:
    the members of my committee, Michael Borman, Robert Meinke, and Evelyn Sherr, for their helpful

  • The Effects of Phytoplankton Prey Species and Nutrient Limitation on Microzooplankton

    Creator:
    McBeain, Kelsey Ann
    Abstract:
    Phytoplankton and microzooplankton comprise the base and the first link of the marine food web, respectively. These microbes are key drivers of marine carbon and nutrient cycles. Phytoplankton convert atmospheric CO₂ into organic carbon, and microzooplankton consume phytoplankton, packaging phytoplankton carbon into particulate forms that have a variety of fates:...
    Resource Type:
    Masters Thesis
    Full Text:
    funneled to higher 17 trophic levels [Sherr & Sherr, 2002]. The fecal matter or dissolved

  • Remineralization of marine particulate organic matter

    Creator:
    Burkhardt, Brian Gary
    Abstract:
    Marine microorganisms play a significant role in the cycling of nutrients in the open ocean through production, consumption, and degradation of organic matter (OM). Carbon (C), nitrogen (N), and phosphorus (P) are essential ingredients in every known recipe for life. However, the cycling of each of these elements proceeds at...
    Resource Type:
    Masters Thesis
    Full Text:
    development in this work and as an individual. I would also like to thank Dr. Ricardo Letelier, Dr. Evelyn

  • A study on the effects of enhanced pCO2 on open ocean diazotrophic assemblages

    Creator:
    Gradoville, Mary Rose
    Abstract:
    Biological di-nitrogen (N₂) fixation is a key process in open-ocean ecosystems, where the new nitrogen (N) provided by marine diazotrophs can support a large fraction of primary productivity and carbon (C) drawdown. Recent laboratory studies have shown that elevated pCO₂ enhances the rate of N₂ fixation by select laboratory isolates...
    Resource Type:
    Masters Thesis