http://hdl.handle.net/1957/1309 http://ir.library.oregonstate.edu/dspace/retrieve/5801 http://hdl.handle.net/1957/1309 Search the Channel search http://ir.library.oregonstate.edu/dspace/simple-search http://hdl.handle.net/1957/9124 Title: An investigation into nitrogen uptake by Emilania huxleyi during continuous darkness <br/> <br/>Abstract: Experiments were conducted with two strains of the coccolithophorid Emiliania huxleyi. Previous experiments with CCMP1742 and 372 at a light intensity of 60 µEin/m²-s showed that during five-day periods of continuous darkness, strain 1742 was taking up nitrate from the media while strain 372 was not. The nitrate uptake in strain 1742 was concurrent with an increase in particulate nitrogen. This observation, combined with the fact that carbon-rich alkenones decreased during the same dark period, led to the hypothesis that amino acids were being synthesized during the continuous darkness period in E. huxleyi strain 1742. This thesis presents results from three separate continuous darkness experiments with E. huxleyi strains 1742 and 372, run at a light intensity of 165 µEin/m²-s. These experiments were conducted to determine whether 1) amino acids are synthesized in E. huxleyi strain 1742 during continuous darkness, 2) this strain is physiologically unique in this regard, and 3) any amino acid accumulation is compound-specific. Two separate and independent methods for amino acid determination were utilized: gas chromatography paired with a flame ionization detector (GC-FID) and the ninhydrin method. Alkenones, media nutrients, and particulate organic carbon and particulate nitrogen (PN) were also measured. Results showed that no dark-period nutrient uptake or PN accumulation occurred in strain 372, in agreement with previous findings. No accumulation of amino acids was displayed in this strain during the continuous darkness period. CCMP1742 displayed nitrogen uptake, PN accumulation, and amino acid synthesis during the first experiment, but not the second or third experiments. The argument is presented that the increased light intensity of 165 µEin/m²-s inhibited the above dark-period nitrogen dynamics. This inhibition may have been overcome in the first experiment due to a previous nutrient stress experienced by the cells used to inoculate the experiment culture. Future experiments should utilize ¹⁵NO₃ to track the media nitrogen into cells, and also investigate the effects of light intensity and nutrient stress on dark-period protein production. <br/> <br/>Description: Graduation date: 2009 http://hdl.handle.net/1957/9104 Title: Robert Hooke and the foundation of geology : a comparison of Steno and Hooke and the Hooke imprint on the Huttonian theory ; and, The tectonic evolution of the Oregon continental margin : rotation of segment boundaries and possible spacetime relationships in the Central High Cascades <br/> <br/>Abstract: Based on the principle that the history of a discipline is important to the discipline itself, this thesis devotes two chapters to ROBERT HOOKE AND THE FOUNDATION OF GEOLOGY and two chapters to modern geology, viz. THE TECTONIC EVOLUTION OF THE OREGON CONTINENTAL MARGIN. The first part of this abstract covers the historical section of the thesis and the second part the scientific section. Robert Hooke was much more than the originator of Hooke's Law or an inventor who invented or perfected meteorological instruments and who pioneered equipment design for sounding the depths of the ocean and collecting ocean water samples at various depths. He supplied Isaac Newton with the concept of centripetal force which allowed Newton to formulate his Laws of Gravitation; he was the first to demonstrate the pressure and volume relationships of gases which were called Boyle's Law. His geological contributions had a profound influence on the development of geology, but they have been largely ignored by modern historians and geologists. The 17th-century Dane Nicolaus Steno has been honored by geologists as a founder of geology and the 18th-century Scotsman James Hutton is widely recognized as the father of modern geology. In a comparison of Steno's geological contributions with those of Hooke, the latter emerges as having made a more extensive and profound contribution. Furthermore, Hooke's system of the earth as presented in his Cutlerian Lectures, published posthumously as Discourse of Earthquakes in 1705, is almost identical to the theory James Hutton announced to the Royal Society of Edinburgh in 1785. This similarity is not a coincidence. That Hutton was thoroughly aware of Hooke's writings is shown not only by the extent to which the intelligentsia of the 18th century cited, quoted and adopted Hooke's ideas, but also by Hutton's own text in both his Abstract of 1785 and his Theory of the Earth in 1788. In the few places where Hutton disagreed with Hooke, Hutton's style became polemical. He seemed to argue against specific points originated by Hooke, which then act as a Hookian signature on the Huttonian Theory. Hooke's influence in the development of geological thought and especially on the foundation of the pre-continental-drift paradigm was a significant one. Robert Hooke, therefore, like Steno, deserves recognition by geologists as a founder of their science. The tectonic evolution of the Oregon continental margin centers around the process of subduction of the Juan de Fuca plate. Models have been advanced to explain the complex tectonic history of this area. The imbricate thrust model seems to test well at the Oregon margin. This model, however, is complicated by the additional processes of segmentation and rotation. This synthesized scenario of the Cenozoic tectonic evolution of the Oregon margin considers the subduction process, including volcanism in the Cascades, as a near-extinction system. This area presently could be experiencing a period of transition from compressional underthrusting to strike-slip motions resulting from extensional forces as the Juan de Fuca plate is coupled with the North America plate. A model involving the rotation of segment boundaries is proposed which may shed some light on time-space and petrologic relationships in the Cascades. The positions of these segment boundaries are supported by bathymetric data on the continental shelf and by the deformation of marine terraces along the Oregon and Washington coasts. Plane vector triangle solutions calculated by Riddihough (1977) for point interactions between the Juan de Fuca plate and the America plate show that the direction of convergence has not been constant over the last 8.5 m.y. The data suggest that the subducted slab had rotated at least 9° in a clockwise direction during the last 1.5 m.y. The model suggests that the arrival of a segment boundary in coincidence with conditions favorable for eruptions may have built the high Central Cascade peaks during the Pleistocene. <br/> <br/>Description: Graduation date: 1981; Presentation date: 1981-03-04 http://hdl.handle.net/1957/9100 Title: An exploration of visitors’ conservation attitudes, expectations, and motivations at three informal education institutions in Newport, Oregon <br/> <br/>Abstract: Due to the overwhelming concern for the current state of our oceans, The Pew Ocean Commission (2003) and the U.S. Commission on Ocean policy (2004), have both strongly recommended an increase in our society’s ocean literacy. An increase in ocean literacy can be achieved through informal education institutions such as zoos, aquarium and science centers. Informal science education institutions are places where visitors engage in free-choice learning on their own terms; having varying amounts of choice over when, how, and with whom they learn. In order to understand whether or not aquarium, zoos, and science centers have an impact on visitors in terms of learning researchers need to be able to document the learning that occurs there. The goal of this study was to explore some newly published tools for understanding what visitors bring with them when visiting informal education institutions. This study looked at visitor motivations, conservation attitudes, and perceptions of a visit to three informal education institutions in Newport, Oregon. It also investigated the effectiveness of using these newly published tools outside of the realm from which they were created. Results of the three administered surveys at each institution revealed that the motivations of visitors to informal education institutions change seasonally. In addition visitor’s conservation attitudes significantly increased from pre to post visit. The findings also revealed that the motivations tool, which was created specifically to measure visitor motivations in zoo and aquariums, was able to successfully measure visitor motivations in such places as a science center and boat excursion company. <br/> <br/>Description: Graduation date: 2009 http://hdl.handle.net/1957/8980 Title: Conservation education in free-choice learning environments : the effects of animals and interpretation <br/> <br/>Abstract: With 150 million people visiting accredited zoos and aquariums annually, these institutions have the unique opportunity to present conservation-oriented messages to a large and receptive audience. The purpose of this study was to explore the role of interpretation and/or the viewing of live animals in the communication of these messages. Research took place at the Oregon Coast Aquarium and the Hatfield Marine Science Center, both located in Newport, Oregon. After viewing these institutions’ respective sea otter exhibits and interpretive programs, participants completed a questionnaire about their conservation attitudes and beliefs, as well as their knowledge of otter natural history. A follow-up survey was also conducted to determine if any long-term changes could be documented as a result of their visit. This study found that visitors who heard the interpretive talk are more familiar with sea otter natural history and could list more specific actions to help these animals than the study's other participants. This group also reported behavior changes as a result of their visit that were not necessarily preceded by a change in attitude. Also included in this thesis are recommendations for researchers and the Oregon Coast Aquarium, as well as implications for the field. <br/> <br/>Description: Graduation date: 2009