Index Catalog // ScholarsArchive@OSU

Photosynthetic Energy Allocation Strategies of Thalassiosira pseudonana During Light Limited Growth

Creator:: Fisher, Nerissa L.
Abstract:: Photosynthetic energy allocation strategies were investigated in the marine diatom, Thalassiosira pseudonana, grown under a wide range of light limitation. Steady-state, continuous cultures were established at three light-limited growth rates. Simultaneous measurements of photosynthetic activity were made that targeted different points in photosynthetic energy flow from gross to net photosynthesis....
Resource Type:: Masters Thesis
Full Text:: Nerissa L. Fisher for the degree of Master of Science in Microbiology presented on June 10, 2015

Impacts of microbial chemical interactions on marine plankton physiology

Creator:: Moore, Eric R.
Abstract:: The bioavailability of chemical compounds in the marine environment fundamentally influences the growth and physiology of microorganisms. Organic and inorganic chemicals that are produced by some marine plankton can be consumed by other plankton for energy production, growth, or to initiate essential physiological processes. Cultures of the diatom Thalassiosira pseudonana,...
Resource Type:: Dissertation
Full Text:: Abstract approved: ______________________________________________________ Kimberly H. Halsey The

Strategies for Altering Energy Flux in Thalassiosira pseudonana Elucidated by Transcriptomics

Creator:: Pombrol, Michelle
Abstract:: Diatoms play a major role in ocean biogeochemical cycles and are important tools in bioengineering for natural products and nanotechnology. Diatoms and other algae growing at varying resource-limited growth rates allocate carbon to different metabolic pathways to optimize growth; however, the molecular mechanisms controlling these pathway gating strategies are not...
Resource Type:: Masters Thesis
Full Text:: : ______________________________________________________ Kimberly Halsey Diatoms play a major role in ocean biogeochemical cycles and are

Quantifying Carbon Production in Marine Ecosystems Using Expressions of Phytoplankton Physiology

Creator:: Penta, William Bryce
Abstract:: Phytoplankton initiate the marine carbon cycle by fixing carbon dioxide into biologically available compounds. These abundant single celled organisms mediate carbon flux from the atmosphere to the deep ocean and are the base of the marine food web, supplying new carbon to higher trophic levels. Phytoplankton are highly diverse and...
Resource Type:: Dissertation
Full Text:: Kimberly H. Halsey Phytoplankton initiate the marine carbon cycle by fixing carbon dioxide into

Physiological characterization of the mixotrophic dinoflagellate Amphidinium carterae

Creator:: Tornberg, Emma C.
Abstract:: Marine primary production can be modeled and estimated using remotely-observable physiological signatures such as chlorophyll and carbon. Current models are based on strict physiological relationships based on photoautotrophic phytoplankton, and discrepancies between modeled and in situ data may stem from unaccounted-for physiological deviations from photoautotrophy. Mixotrophic phytoplankton can obtain energy...
Resource Type:: Honors College Thesis
Full Text:: :_____________________________________________________ Kimberly Halsey Marine primary production can be modeled and estimated using remotely

Chemical and Genetic Investigations of Toxic Freshwater Cyanobacterial Blooms for Improved Monitoring and Understanding of Lake Ecology

Creator:: Collart, Lindsay P.
Abstract:: Toxin production by cyanobacterial harmful algal blooms (cyanoHABs) in freshwater systems has lasting ecological and human impacts. Nutrients, light availability, hydrology, and microbial community composition impact the frequency and intensity of toxic cyanoHABs. Climate change will exacerbate toxic cyanoHABs, making real time and predictive monitoring a vital tool for managing...
Resource Type:: Dissertation
Full Text:: Kimberly H. Halsey Toxin production by cyanobacterial harmful algal blooms (cyanoHABs) in freshwater

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:: : ______________________________________________________ Kimberly H. Halsey Phytoplankton and microzooplankton comprise the base and the first link

Arsenic methylation by marine cyanobacteria Prochlorococcus and Synechococcus

Creator:: Lee, Mikaela
Abstract:: Our experiments aimed to investigate responses of the marine cyanobacteria Prochlorococcus and Synechococcus to toxic arsenic species, such as arsenate, and to understand cellular mechanisms that contribute to arsenic tolerance. We used two strains of Prochlorococcus, a high-light adapted MED4 and low-light adapted MIT9313, both axenic, for cultivation experiments. For...
Resource Type:: Honors College Thesis
Full Text:: _____________________________________________________________________ Kimberly Halsey, Committee Member, representing Microbiology

Controlling Important Pathogens in Zebrafish (Danio rerio) : Assessing Cryopreservation Survival of Bacteria and Parasites and Clinical Sensitivity of Mycobacterial qPCR Assays

Creator:: Norris, Lauren J.
Abstract:: Zebrafish (Danio rerio) are one of the most commonly used animal models in biomedical research. Zebrafish resource facilities, like the Zebrafish International Resource Center (ZIRC) in Eugene, Oregon, are the main providers and keepers of numerous zebrafish wild-type, mutant, and transgenic lines. Although ZIRC maintains live zebrafish at various life...
Resource Type:: Masters Thesis
Full Text:: Michael L. Kent Zebrafish (Danio rerio) are one of the most commonly used animal models in

Characterizing the Accuracy of Phylogenetic Analyses that Leverage 16S rRNA Sequencing Data

Creator:: Humphreys, Ian R.
Abstract:: Investigations of 16S rRNA gene sequences hallmark modern microbiology. These sequences provide culture-independent insight into the abundance and distribution of microbiota and serve as a principle resource through which microbial community diversity is measured. Consequently, researchers rely on 16S gene sequences to test hypotheses rooted in ecology, evolution, and disease....
Resource Type:: Masters Thesis
Full Text:: like to thank Dr. Jeff Chang, Dr. Kimberly Halsey, and Dr. Rebecca Vega Thurber for their time

Species- and Temporal-Specific Coral Microbiome Fluctuations in Response to a Natural Bleaching Event

Creator:: Ewton, Erica M.
Abstract:: Corals provide a diversity of ecosystem services, are among the most biologically diverse ecosystems on Earth, and directly support ~500 million people globally; however, corals are increasingly experiencing significant threats and are undergoing severe bleaching events as the result of the warming climate. Using a two-year data set surrounding a...
Resource Type:: Masters Thesis

Transcriptome Responses of the Nitrifying Bacteria Nitrosomonas europaea and Nitrobacter hamburgensis to Low Oxygen

Creator:: Dobie, Michael
Abstract:: Nitrification is the process within the global Nitrogen Cycle where ammonia (NH3) is oxidized to nitrate (NO₃⁻) and can be carried out by two distinct groups of bacteria. The ammonia-oxidizing bacteria (AOB) first oxidize NH₃ to nitrite (NO₂⁻), and second, the nitrite-oxidizing bacteria (NOB) oxidize NO₂⁻ to NO₃⁻. In aerobic...
Resource Type:: Masters Thesis
Full Text:: . Additionally, their support in the laboratory was critical to my success. Thank you to Dr. Kimberly Halsey

Gadusol Production in Saccharomyces cerevisiae

Creator:: Holzwarth, Garrett
Abstract:: Gadusol is a UV-B-absorbent compound found in fish and other marine organisms where it is presumed to play a role as a sunscreen and antioxidant. In light of commercial potential as a replacement for problematic synthetic sunscreens, a process to produce recombinant gadusol in the yeast Saccharomcyces cerevisiae was investigated....
Resource Type:: Masters Thesis
Full Text:: . cerevisiae to generate strain G0 that produced about 12 mg/L. A number of genetic and cultural

Biogeochemical Processing of Freshwater Carbon in the Anthropocene

Creator:: Buser, Jessica Z.
Abstract:: Freshwater systems cycle carbon along a spatial and temporal biogeochemical continuum, across which ecosystem processes contribute to transformations of organic matter (OM). Various ecological constraints impact rates OM transformation and production and consumption of the energetic end of respiration, methane. Microbiological processing and complete reduction of carbon substrates to methane...
Resource Type:: Dissertation

The frequency of Ceratonova shasta genotypes in Manayunkia speciosa host genotypes

Creator:: Messmer, Madison M.
Abstract:: Ceratonova shasta is a myxozoan parasite that affects populations of salmonid species in the Pacific Northwest and is the cause of enteronecrosis. It has a complex life cycle involving two hosts; a definitive annelid host, Manayunkia speciosa (polychaete), and an intermediate salmonid host. Klamath River M. speciosa are genetically variable...
Resource Type:: Honors College Thesis
Full Text:: , Committee Member, representing Microbiology Kimberly Halsey, Committee Member, representing

Distribution of Ceratomyxa shasta (Myxozoa) and habitat preference of the polychaete host, Manayunkia speciosa in the Klamath River

Creator:: Stocking, Richard W.
Abstract:: Ceratomyxa shasta is a myxozoan parasite of salmonids and requires the freshwater polychaete, Manayunkia speciosa to complete its life cycle. The parasite’s distribution is currently limited to the Pacific Northwest region of North America and has been reported to cause substantial losses of both wild and hatchery salmonids. The spatial...
Resource Type:: Masters Thesis
Full Text:: : __________________________________________________ Jerri L. Bartholomew Ceratomyxa shasta is a myxozoan parasite of salmonids and requires

A study of corynebacterial kidney disease of salmonid fishes

Creator:: Rowse-Eagle, Debra H.
Abstract:: This study was undertaken to compile a comprehensive review of the literature and to gain a better understanding of the host-parasite relationship in corynebacterial kidney disease of salmonid fishes. An indirect fluorescent antibody technique was developed which allowed differentiation of intra- and extracellular bacteria. This technique was used in combination...
Resource Type:: Masters Thesis
Full Text:: Abstract approved: Redacted for privacy L. Fryy* This study was undertaken to compile a comprehensive

The Influence of Microbial Communities on Spatiotemporal Elemental Cycling in Coastal Margins Revealed by Community- and Population-level Genomics and Proteomics

Creator:: Kieft, Brandon P.
Abstract:: Biotic and abiotic processes at continent-ocean interfaces cycle a disproportionate mass of carbon and nutrients relative to their global surface area, and microbial activity is a principal determinant of organic and inorganic matter flux in these transition zones. Most studies using modern high-throughput ‘omics techniques to link microorganisms with costal...
Resource Type:: Dissertation

The effects of X-ray CT scanning on microbial communities in sediment cores

Creator:: Ewton, Erica
Abstract:: Using X-ray computed tomography (CT) scanning to characterize the physical characteristics of soil and sediment cores allows scientists to observe and analyze stratigraphy without destroying the integrity of different layers. Microbiologists often work with geologists to characterize the microbial communities in such cores; however, X-rays are known to be destructive...
Resource Type:: Honors College Thesis
Full Text:: _____________________________________________________________________ Kimberly Halsey, Committee Member, representing Microbiology

Control of alkane monooxygenase activity and expression in Pseudomonas butanovora

Creator:: Doughty, David M.
Abstract:: The regulation of monooxygenase enzymes has been demonstrated in bacteria that grow on methane and long chain-length alkanes (>C10). Less is known about monooxygenase regulation in short chain alkane oxidizing bacteria that grow on intermediate chain-length alkanes C2-C10. This dissertation focuses on the regulation of butane monooxygenase (BMO) expression and...
Resource Type:: Dissertation
Full Text:: Sayavedra-Soto, Kimberly H. Halsey and Elizabeth Kurth who selflessly provided time and assistance

Influence of interplanted and pure stands of red alder (Alnus rubra Bong.) on microbial and chemical characteristics of a coastal forest soil in the Douglas-fir region

Creator:: Chen, Chi-sin
Abstract:: Chemical and microbial analyses were made at four seasonal intervals on soil horizons under red alder, conifers, and mixed alder-conifers at the Cascade Head Experimental Forest, established in 1937 by the U. S. Forest Service near Otis, Oregon. Microbial analyses showed that although plate counts of molds and bacteria fluctuated...
Resource Type:: Dissertation
Full Text:: , John L. Neal, Jr.., and Fred Au, who contributed support and many valuable discussions, thanks are

A Comparative Study between Mental Health of Homeless Populations in the United States and Spain

Creator:: Helman, Talia
Abstract:: Many people around the world suffer from a mental illness, and too few receive the help they need. Mental illness is especially prevalent among the homeless. Homelessness is represented in all ages, ethnicities, and genders, and is especially represented among first world countries such as the United States and Spain....
Resource Type:: Honors College Thesis

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