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• 311. [Article] Trends of tax levies in Oregon with emphasis upon rural and city real properties

  Published November 1929. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/cata...

  Citation × Citation Citation Abstract Copy Title: Trends of tax levies in Oregon with emphasis upon rural and city real properties Author: Dreesen, W. H. (William Henry), 1880-, Oregon State Agricultural College. Agricultural Experiment Station Published November 1929. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Title: Trends of tax levies in Oregon with emphasis upon rural and city real properties Author: Dreesen, W. H. (William Henry), 1880-, Oregon State Agricultural College. Agricultural Experiment Station Published November 1929. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Close

• 312. [Article] Photoluminescence Detection of 2,4,6-Trinitrotoulene (TNT) Binding on Single Cell Diatom Biosilica

  T. pseudonana biosilica and live cells was explored as a biosensor for detection of the explosive compound 2,4,6-trinitrotoluene (TNT) in aqueous solution. The diatom frustule is an intricately nanostructured, ...

  Citation × Citation Citation Abstract Copy Title: Photoluminescence Detection of 2,4,6-Trinitrotoulene (TNT) Binding on Single Cell Diatom Biosilica Author: Harms, Nathan D. T. pseudonana biosilica and live cells was explored as a biosensor for detection of the explosive compound 2,4,6-trinitrotoluene (TNT) in aqueous solution. The diatom frustule is an intricately nanostructured, highly porous biogenic silica material derived from the shells of microscopic algae called diatoms. This material emits strong visible blue photoluminescence (PL) upon UV excitation. PL-active frustule biosilica was isolated from cultured cells of the marine diatom T. pseudonana, exposed to varying concentrations of TNT, and the PL response was observed using PL spectroscopy. This process was repeated for live T. pseudonana cells. Both experiments showed distinct trends and an attempt at explanation was made. Title: Photoluminescence Detection of 2,4,6-Trinitrotoulene (TNT) Binding on Single Cell Diatom Biosilica Author: Harms, Nathan D. T. pseudonana biosilica and live cells was explored as a biosensor for detection of the explosive compound 2,4,6-trinitrotoluene (TNT) in aqueous solution. The diatom frustule is an intricately nanostructured, highly porous biogenic silica material derived from the shells of microscopic algae called diatoms. This material emits strong visible blue photoluminescence (PL) upon UV excitation. PL-active frustule biosilica was isolated from cultured cells of the marine diatom T. pseudonana, exposed to varying concentrations of TNT, and the PL response was observed using PL spectroscopy. This process was repeated for live T. pseudonana cells. Both experiments showed distinct trends and an attempt at explanation was made. Close

• 313. [Article] Geology and geochemistry of Juniper Ridge, Horsehead Mountain and Burns Butte : implications for the petrogenesis of silicic magma on the High Lava Plains, southeastern Oregon

  The Juniper Ridge volcanic complex is located in the High Lava Plains Province of southeastern Oregon, a wide zone of bimodal volcanism and faulting that marks the northern limit of widespread Basin and ...

  Citation × Citation Citation Abstract Copy Title: Geology and geochemistry of Juniper Ridge, Horsehead Mountain and Burns Butte : implications for the petrogenesis of silicic magma on the High Lava Plains, southeastern Oregon Author: MacLean, James W. The Juniper Ridge volcanic complex is located in the High Lava Plains Province of southeastern Oregon, a wide zone of bimodal volcanism and faulting that marks the northern limit of widespread Basin and Range-style faulting in the northern Great Basin Province. Rhyolite dome complexes are progressively younger to the northwest along the High Lava Plains, providing a mirror-image to age-progressive silicic volcanism on the Snake River Plain in southern Idaho. 40Ar-39Ar dating of rocks from western and eastern Juniper Ridge (5.70 ± 0.02 Ma and 6.87 ± 0.02 Ma, respectively) and Burns Butte (7.75 ± 0.06 Ma) confirms the overall age progression, and shows that age relations within the Juniper Ridge complex are consistent with the trend. Horsehead Mountain (15.54 ± 0.03 Ma) predates the age progression altogether. Rocks at both eastern Juniper Ridge and western Juniper Ridge are overlain by diktytaxitic olivine basalt flows similar to regional high-alumina olivine tholeiites (HAOTs). At western Juniper Ridge, high-silica rhyolite flows overlie lower-silica rhyolite and hybrid andesite flows. At eastern Juniper Ridge, a suite of intermediate rocks ranging from basaltic andesite to dacite overlies a series of rhyolite flows. Rocks at Burns Butte consist of high-silica rhyolite, porphyritic dacite and rhyodacite, and andesite. Field and petrographic observations, including mixing textures, inclusions, and xenocrysts, along with straight-line relationships on chemical diagrams, show that the intermediate rocks at western Juniper Ridge formed by mixing between high-silica rhyolite magma and slightly evolved HAOT, probably at the base of a large silicic magma chamber. In contrast, curvilinear geochemical trends and an internally consistent four-stage major and trace element model suggest that intermediate rocks at eastern Juniper Ridge evolved in small, unconnected magma chambers by removal of olivine, plagioclase, clinopyroxene, and magnetite from a primitive HAOT parent, accompanied by contamination by up to 22 percent rhyolite. Unusually elevated concentrations of incompatible trace elements in the Squaw Butte basaltic andesite were produced by either zone refining or combined fractionation and recharge. The least-evolved rhyolites at eastern and western Juniper Ridge have lower rare-earth element concentrations than the intermediate fractionates at eastern Juniper Ridge, thus precluding an origin by crystal fractionation from the observed intermediate rocks, but have major element compositions close to those of experimental dehydration melts of amphibolite. The rhyolites probably originated as dehydration melts of an amphibolite lower crust, which were subsequently modified by removal of quartz, sanidine, plagioclase, clinopyroxene and zircon. At western Juniper Ridge, the fractionating assemblage probably included trace allanite. Rhyolites from dome complexes and ash-flow tufts of the 5- to 10-Ma portion of the ageprogressive trend show systematic trace element variations with position along the trend. Dome complexes include Burns Butte, Palomino Butte, eastern and western Juniper Ridge and Glass Buttes; ash-flow tufts include the Devine Canyon Tuft, the Prater Creek Tuft, the Rattlesnake Tuff and the tuft of Buckaroo Lake. From east to west, Y/Nb and Yb/Ta increase, and Ce/Yb decreases in the least-evolved rhyolite in each suite. These variations can be accounted for by a systematic increase in degree of garnet-residual partial melting of amphibolite crust from east to west, correlating either with degree of extension with time along the Brothers fault zone, or with distance from the main axis of faulting. Porphyritic, calc-alkaline andesites and dacites erupted from at least six vents at Horsehead Mountain. Field relationships indicate a general decrease in age from southwest to northeast within the complex. At 15 Ma, calc-alkaline volcanism at Horsehead Mountain predates the age-progressive rhyolftes, and is instead part of an earlier phase of volcanism that produced the Steens and Columbia River flood basalts, along with several other caic-alkaline intermediate centers that are unrelated to subduction. Overlapping rare-earth element patterns of Horsehead Mountain intermediate rocks with those of Steens basalts precludes their derivation by fractionation from the broadly contemporaneous flood basalts. Title: Geology and geochemistry of Juniper Ridge, Horsehead Mountain and Burns Butte : implications for the petrogenesis of silicic magma on the High Lava Plains, southeastern Oregon Author: MacLean, James W. The Juniper Ridge volcanic complex is located in the High Lava Plains Province of southeastern Oregon, a wide zone of bimodal volcanism and faulting that marks the northern limit of widespread Basin and Range-style faulting in the northern Great Basin Province. Rhyolite dome complexes are progressively younger to the northwest along the High Lava Plains, providing a mirror-image to age-progressive silicic volcanism on the Snake River Plain in southern Idaho. 40Ar-39Ar dating of rocks from western and eastern Juniper Ridge (5.70 ± 0.02 Ma and 6.87 ± 0.02 Ma, respectively) and Burns Butte (7.75 ± 0.06 Ma) confirms the overall age progression, and shows that age relations within the Juniper Ridge complex are consistent with the trend. Horsehead Mountain (15.54 ± 0.03 Ma) predates the age progression altogether. Rocks at both eastern Juniper Ridge and western Juniper Ridge are overlain by diktytaxitic olivine basalt flows similar to regional high-alumina olivine tholeiites (HAOTs). At western Juniper Ridge, high-silica rhyolite flows overlie lower-silica rhyolite and hybrid andesite flows. At eastern Juniper Ridge, a suite of intermediate rocks ranging from basaltic andesite to dacite overlies a series of rhyolite flows. Rocks at Burns Butte consist of high-silica rhyolite, porphyritic dacite and rhyodacite, and andesite. Field and petrographic observations, including mixing textures, inclusions, and xenocrysts, along with straight-line relationships on chemical diagrams, show that the intermediate rocks at western Juniper Ridge formed by mixing between high-silica rhyolite magma and slightly evolved HAOT, probably at the base of a large silicic magma chamber. In contrast, curvilinear geochemical trends and an internally consistent four-stage major and trace element model suggest that intermediate rocks at eastern Juniper Ridge evolved in small, unconnected magma chambers by removal of olivine, plagioclase, clinopyroxene, and magnetite from a primitive HAOT parent, accompanied by contamination by up to 22 percent rhyolite. Unusually elevated concentrations of incompatible trace elements in the Squaw Butte basaltic andesite were produced by either zone refining or combined fractionation and recharge. The least-evolved rhyolites at eastern and western Juniper Ridge have lower rare-earth element concentrations than the intermediate fractionates at eastern Juniper Ridge, thus precluding an origin by crystal fractionation from the observed intermediate rocks, but have major element compositions close to those of experimental dehydration melts of amphibolite. The rhyolites probably originated as dehydration melts of an amphibolite lower crust, which were subsequently modified by removal of quartz, sanidine, plagioclase, clinopyroxene and zircon. At western Juniper Ridge, the fractionating assemblage probably included trace allanite. Rhyolites from dome complexes and ash-flow tufts of the 5- to 10-Ma portion of the ageprogressive trend show systematic trace element variations with position along the trend. Dome complexes include Burns Butte, Palomino Butte, eastern and western Juniper Ridge and Glass Buttes; ash-flow tufts include the Devine Canyon Tuft, the Prater Creek Tuft, the Rattlesnake Tuff and the tuft of Buckaroo Lake. From east to west, Y/Nb and Yb/Ta increase, and Ce/Yb decreases in the least-evolved rhyolite in each suite. These variations can be accounted for by a systematic increase in degree of garnet-residual partial melting of amphibolite crust from east to west, correlating either with degree of extension with time along the Brothers fault zone, or with distance from the main axis of faulting. Porphyritic, calc-alkaline andesites and dacites erupted from at least six vents at Horsehead Mountain. Field relationships indicate a general decrease in age from southwest to northeast within the complex. At 15 Ma, calc-alkaline volcanism at Horsehead Mountain predates the age-progressive rhyolftes, and is instead part of an earlier phase of volcanism that produced the Steens and Columbia River flood basalts, along with several other caic-alkaline intermediate centers that are unrelated to subduction. Overlapping rare-earth element patterns of Horsehead Mountain intermediate rocks with those of Steens basalts precludes their derivation by fractionation from the broadly contemporaneous flood basalts. Close

• 314. [Article] Dental Amalgam Fillings: The Scientific Evidence for Safety

  Objective: To explore the controversial issue of the safety and use of mercury in amalgam dental fillings. Methods: Using a variety of scientifically oriented studies, overall trends and conclusions were ...

  Citation × Citation Citation Abstract Copy Title: Dental Amalgam Fillings: The Scientific Evidence for Safety Author: Young, Matthew J. Objective: To explore the controversial issue of the safety and use of mercury in amalgam dental fillings. Methods: Using a variety of scientifically oriented studies, overall trends and conclusions were analyzed. Relevant articles include Children’s exposure to Amalgam, fetal exposure, environmental mercury, occupational exposure, and mercury and Multiple Sclerosis. Additional literatures available to the public were also analyzed to provide background on the general public’s access to information regarding amalgam. Results: Many studies used analyzed mercury content of the urine, a key factor when deciding the toxicity of mercury in amalgam fillings. Most studies found little or no correlation between amalgam fillings and toxicity to the human body. Conclusion: The bulk of the evidence to date supports the use of mercury amalgam as probably safe. Key Title: Dental Amalgam Fillings: The Scientific Evidence for Safety Author: Young, Matthew J. Objective: To explore the controversial issue of the safety and use of mercury in amalgam dental fillings. Methods: Using a variety of scientifically oriented studies, overall trends and conclusions were analyzed. Relevant articles include Children’s exposure to Amalgam, fetal exposure, environmental mercury, occupational exposure, and mercury and Multiple Sclerosis. Additional literatures available to the public were also analyzed to provide background on the general public’s access to information regarding amalgam. Results: Many studies used analyzed mercury content of the urine, a key factor when deciding the toxicity of mercury in amalgam fillings. Most studies found little or no correlation between amalgam fillings and toxicity to the human body. Conclusion: The bulk of the evidence to date supports the use of mercury amalgam as probably safe. Key Close

• 315. [Article] Perceived Credibility of News Media Sources

  The purpose of this research is to study the relationship between popular news media sources and individual perceptions of media credibility. Findings in this research show that there is a relationship ...

  Citation × Citation Citation Abstract Copy Title: Perceived Credibility of News Media Sources Author: Palczewski, Nicole The purpose of this research is to study the relationship between popular news media sources and individual perceptions of media credibility. Findings in this research show that there is a relationship between media credibility, media habits, and media trust, which affects the choice of media that an individual determines is credible. Using a quasi-experimental survey, information was collected from a representative sample of the U.S. population on their opinions of the credibility of 19 mainstream news media outlets after reading an article about the passage of recreational marijuana laws in Alaska. Analysis of the findings from these experiments indicates that media trust is positively correlated with media credibility; media habits show less stable results. This research finds a trend of different audiences for different news sources, with a split between ‘sophisticated skeptics’ and ‘the less well informed’, as seen in previous research. These results are discussed for their theoretical implications. Title: Perceived Credibility of News Media Sources Author: Palczewski, Nicole The purpose of this research is to study the relationship between popular news media sources and individual perceptions of media credibility. Findings in this research show that there is a relationship between media credibility, media habits, and media trust, which affects the choice of media that an individual determines is credible. Using a quasi-experimental survey, information was collected from a representative sample of the U.S. population on their opinions of the credibility of 19 mainstream news media outlets after reading an article about the passage of recreational marijuana laws in Alaska. Analysis of the findings from these experiments indicates that media trust is positively correlated with media credibility; media habits show less stable results. This research finds a trend of different audiences for different news sources, with a split between ‘sophisticated skeptics’ and ‘the less well informed’, as seen in previous research. These results are discussed for their theoretical implications. Close

• 316. [Article] The Role of Political Party in Health Policy

  The role of political parties within legislation has been greatly debated over the decades. As health care continues to be an issue of concerns and contention, the question of how politics affects this ...

  Citation × Citation Citation Abstract Copy Title: The Role of Political Party in Health Policy Author: Rusetskiy, Karina I. The role of political parties within legislation has been greatly debated over the decades. As health care continues to be an issue of concerns and contention, the question of how politics affects this industry is of importance. Utilizing Congressional records and websites to determine roll call and voice voting within both chambers of Congress, allowed for the analysis of voting patterns and trends. The data demonstrated that control of both the Legislative and Executive branch were ultimately not needed for passage of health policy and that there is no strong definitive split among the parties toward specific policy subjects within health care. Both parties have made significant contributions, and historically have overwhelmingly worked together to pass health related policy. Title: The Role of Political Party in Health Policy Author: Rusetskiy, Karina I. The role of political parties within legislation has been greatly debated over the decades. As health care continues to be an issue of concerns and contention, the question of how politics affects this industry is of importance. Utilizing Congressional records and websites to determine roll call and voice voting within both chambers of Congress, allowed for the analysis of voting patterns and trends. The data demonstrated that control of both the Legislative and Executive branch were ultimately not needed for passage of health policy and that there is no strong definitive split among the parties toward specific policy subjects within health care. Both parties have made significant contributions, and historically have overwhelmingly worked together to pass health related policy. Close

• 317. [Article] Student Understanding and Generalization of Functions from Single to Multivariable Calculus

  Students struggle with the concept of functions and the notation associated with it in various mathematical contexts. This thesis investigates student understanding of function notation through their generalization ...

  Citation × Citation Citation Abstract Copy Title: Student Understanding and Generalization of Functions from Single to Multivariable Calculus Author: Kerrigan, Sarah Students struggle with the concept of functions and the notation associated with it in various mathematical contexts. This thesis investigates student understanding of function notation through their generalization of single variable functions to multivariable functions in a variety of situations. Semi-structured student interviews were conducted and analyzed through a framework using concept image and concept definition coupled with an actor-oriented generalization taxonomy. The findings suggest that students relate back to forms and situations from single variable to assign meaning to multivariable functions. Several teaching implications are suggested based on the trends that emerged in how students understand functions and notation. Title: Student Understanding and Generalization of Functions from Single to Multivariable Calculus Author: Kerrigan, Sarah Students struggle with the concept of functions and the notation associated with it in various mathematical contexts. This thesis investigates student understanding of function notation through their generalization of single variable functions to multivariable functions in a variety of situations. Semi-structured student interviews were conducted and analyzed through a framework using concept image and concept definition coupled with an actor-oriented generalization taxonomy. The findings suggest that students relate back to forms and situations from single variable to assign meaning to multivariable functions. Several teaching implications are suggested based on the trends that emerged in how students understand functions and notation. Close

• 318. [Article] Human Visitation in the Rocky Intertidal and its Effects on Abundance of Algal and Invertebrate Species

  The rocky intertidal is a diverse ecosystem with a variety of species and ecological interactions. Many biotic and abiotic interactions act together to restrict the abundance and distribution of species. ...

  Citation × Citation Citation Abstract Copy Title: Human Visitation in the Rocky Intertidal and its Effects on Abundance of Algal and Invertebrate Species Author: Silbernagel, Justin J. The rocky intertidal is a diverse ecosystem with a variety of species and ecological interactions. Many biotic and abiotic interactions act together to restrict the abundance and distribution of species. Anthropogenic effects can have an important impact on species abundance and distribution as well. This study looks at how human visitation affects community structure in the rocky intertidal along the Oregon coast. Areas of high human visitation were found to have lower species richness than areas of low visitation in the lower vertical zones of the rocky intertidal. However, species richness was found to be higher in high visitation areas in the highest intertidal zone. Abundance of species differed between areas of high and low human visitation, but showed few overall significant trends. Title: Human Visitation in the Rocky Intertidal and its Effects on Abundance of Algal and Invertebrate Species Author: Silbernagel, Justin J. The rocky intertidal is a diverse ecosystem with a variety of species and ecological interactions. Many biotic and abiotic interactions act together to restrict the abundance and distribution of species. Anthropogenic effects can have an important impact on species abundance and distribution as well. This study looks at how human visitation affects community structure in the rocky intertidal along the Oregon coast. Areas of high human visitation were found to have lower species richness than areas of low visitation in the lower vertical zones of the rocky intertidal. However, species richness was found to be higher in high visitation areas in the highest intertidal zone. Abundance of species differed between areas of high and low human visitation, but showed few overall significant trends. Close

• 319. [Article] I-V Characteristics of Al/HfO2/TaN RRAM Devices

  The memristor is a resistive switching random access memory (RRAM) with a basic metal/insulator/metal (MIM) structure. These nano devices are nonvolatile, have a conceptually simple crossbar device structure, ...

  Citation × Citation Citation Abstract Copy Title: I-V Characteristics of Al/HfO2/TaN RRAM Devices Author: Valdivia, Arturo H. The memristor is a resistive switching random access memory (RRAM) with a basic metal/insulator/metal (MIM) structure. These nano devices are nonvolatile, have a conceptually simple crossbar device structure, are power efficient and have the capability of switching between high and low resistance states in nanoseconds making them promising to replace current forms of memory storage. In this thesis Al/HfO₂/TaN RRAM devices were synthesized and bipolar switching was observed. I-V curves for devices of different areas were obtained and characteristics with regards to the set and reset voltages were attributed to literature trends for future production of stable devices. Title: I-V Characteristics of Al/HfO2/TaN RRAM Devices Author: Valdivia, Arturo H. The memristor is a resistive switching random access memory (RRAM) with a basic metal/insulator/metal (MIM) structure. These nano devices are nonvolatile, have a conceptually simple crossbar device structure, are power efficient and have the capability of switching between high and low resistance states in nanoseconds making them promising to replace current forms of memory storage. In this thesis Al/HfO₂/TaN RRAM devices were synthesized and bipolar switching was observed. I-V curves for devices of different areas were obtained and characteristics with regards to the set and reset voltages were attributed to literature trends for future production of stable devices. Close

• 320. [Article] The antibiotic discovery era (1940-1960) : vancomycin as an example of the era

  An examination of the technical and historical literature concerning the discovery and development of antibiotics suggests the possible existence of an era of discovery. This era appears to have a well-defined ...

  Citation × Citation Citation Abstract Copy Title: The antibiotic discovery era (1940-1960) : vancomycin as an example of the era Author: McGraw, Donald J. An examination of the technical and historical literature concerning the discovery and development of antibiotics suggests the possible existence of an era of discovery. This era appears to have a well-defined beginning (about 1940) and a well-defined close (about 1960). It is the purpose of this dissertation to examine the various strands of evidence that support the thesis that a definable antibiotic discovery era does indeed exist. An examination of several antibiotics discovered and developed during the period 1940-1960 support the thesis. One antibiotic in particular, vancomycin, discussed in depth is shown to be exemplary of the trends established about 1940 and which ceased to function about 1960. In concluding, a definition for the discovery era is proposed. Title: The antibiotic discovery era (1940-1960) : vancomycin as an example of the era Author: McGraw, Donald J. An examination of the technical and historical literature concerning the discovery and development of antibiotics suggests the possible existence of an era of discovery. This era appears to have a well-defined beginning (about 1940) and a well-defined close (about 1960). It is the purpose of this dissertation to examine the various strands of evidence that support the thesis that a definable antibiotic discovery era does indeed exist. An examination of several antibiotics discovered and developed during the period 1940-1960 support the thesis. One antibiotic in particular, vancomycin, discussed in depth is shown to be exemplary of the trends established about 1940 and which ceased to function about 1960. In concluding, a definition for the discovery era is proposed. Close