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• 91. [Article] Early forest succession following clearcuts in western Oregon : patterns and abiotic controls

  Historical aerial photos were used to examine the early phase of forest succession after stand replacement disturbance, covering the Coast Ranges Province (CRP) and the western Cascades Province (WCP) ...

  Citation × Citation Citation Abstract Copy Title: Early forest succession following clearcuts in western Oregon : patterns and abiotic controls Author: Yang, Zhiqiang Historical aerial photos were used to examine the early phase of forest succession after stand replacement disturbance, covering the Coast Ranges Province (CRP) and the western Cascades Province (WCP) of western Oregon. The study consisted of two components: characterizing the pattern of forest succession in western Oregon; analyzing the influence of climatic and physiographic factors on forest succession. Succession has many dimensions. In this study, I examined succession after stand replacement disturbance in terms of canopy cover change of different life forms: shrubs, hardwood trees, and conifer trees. Canopy cover changes from 1959 to 1997 for selected sample stands were obtained by photo interpretation. Canopy cover growth curves for each sample stand were developed based on a Chapman-Richards growth function. Seven successional pathways were defined to characterize forest successional processes based on projected canopy cover at age 50 and the process of canopy composition change over this 50 years period. In addition, seven parameters from the canopy cover growth curves were derived for the purpose of comparison of successional patterns in the CRP and WCP. These include time to reach 5% and 70% of canopy cover, weighted mean absolute growth rate, weighted mean relative growth rate, maximum absolute growth rate, time to reach maximum absolute growth rate, and active growth period. Results indicated that a wide range of variation in forest succession exists in western Oregon. Successional patterns for the CRP and WCP were different in terms of conifer development. Possible abiotic controls of two successional parameters were examined by stepwise regression analysis. Only 23%, 37%, and 29% of the total variation in the delay, and 29%, 25% and 57% of the total variation in rate parameters can be explained by abiotic factors for the WCP, CRP, and across provinces, respectively. Unexplained variation was likely due to stochastic, biotic, and management factors, as well as experimental error due to photo interpretation and derivation of successional paramters. The most important influential climatic factor was temperature, and the most important physiographic factor was elevation. Depending on location, interactions among climatic and physiographic factors also influenced successional delay and rate. Title: Early forest succession following clearcuts in western Oregon : patterns and abiotic controls Author: Yang, Zhiqiang Historical aerial photos were used to examine the early phase of forest succession after stand replacement disturbance, covering the Coast Ranges Province (CRP) and the western Cascades Province (WCP) of western Oregon. The study consisted of two components: characterizing the pattern of forest succession in western Oregon; analyzing the influence of climatic and physiographic factors on forest succession. Succession has many dimensions. In this study, I examined succession after stand replacement disturbance in terms of canopy cover change of different life forms: shrubs, hardwood trees, and conifer trees. Canopy cover changes from 1959 to 1997 for selected sample stands were obtained by photo interpretation. Canopy cover growth curves for each sample stand were developed based on a Chapman-Richards growth function. Seven successional pathways were defined to characterize forest successional processes based on projected canopy cover at age 50 and the process of canopy composition change over this 50 years period. In addition, seven parameters from the canopy cover growth curves were derived for the purpose of comparison of successional patterns in the CRP and WCP. These include time to reach 5% and 70% of canopy cover, weighted mean absolute growth rate, weighted mean relative growth rate, maximum absolute growth rate, time to reach maximum absolute growth rate, and active growth period. Results indicated that a wide range of variation in forest succession exists in western Oregon. Successional patterns for the CRP and WCP were different in terms of conifer development. Possible abiotic controls of two successional parameters were examined by stepwise regression analysis. Only 23%, 37%, and 29% of the total variation in the delay, and 29%, 25% and 57% of the total variation in rate parameters can be explained by abiotic factors for the WCP, CRP, and across provinces, respectively. Unexplained variation was likely due to stochastic, biotic, and management factors, as well as experimental error due to photo interpretation and derivation of successional paramters. The most important influential climatic factor was temperature, and the most important physiographic factor was elevation. Depending on location, interactions among climatic and physiographic factors also influenced successional delay and rate. Close

• 92. [Article] Analyzing fire mosaics in temperate coniferous forests with GIS and remote sensing

  This investigation on fire mosaics addressed several aspects: (1) quantifying the role of terrain variables in fire-related mortality and historical mean fire return interval (MFRI), (2) comparing post-burn ...

  Citation × Citation Citation Abstract Copy Title: Analyzing fire mosaics in temperate coniferous forests with GIS and remote sensing Author: Kushla, John D. This investigation on fire mosaics addressed several aspects: (1) quantifying the role of terrain variables in fire-related mortality and historical mean fire return interval (MFRI), (2) comparing post-burn Landsat Thematic Mapper (TM) imagery, TM difference imagery, and aerial photo interpretation to map forest survival after wildfire, and (3) to describe and discuss wildfire effects on successional stage patterns and wildlife habitat. The two study sites were located on the Willamette National Forest in the Oregon Cascades. The Warner Creek burn was the location of a 1991 wildfire covering 3669 ha; the Upper McKenzie site was the location of ecological and historical fire studies. Historical MFRI, terrain, and vegetation data were input into a geographical information system. Random sampling was conducted on all layers, and was also used to ground truth forest survival, primarily with aerial photography. Relationships of terrain to forest survival and historical MFRI were analyzed with regression. Regression was also used to model forest survival with TM data. Error matrices were used to compare classified TM data and aerial photo interpretation in mapping survival. At both sites, terrain variables accounted for more variation in forest survival (12-62%) or historical MFRI (4.8-21.9%) within individual physiographic areas, than across the respective study areas. Moreover, the significant topographic variables differed among individual physiographic areas. Regressions of TM band transformations were used to evaluate forest survival. The TM difference imagery with stratification by pre-f ire tasseled cap (TC) wetness explained 75% of the variation in live canopy ratio, and post-burn TM Structural Index (SI) accounted for 72%. Classification of the TM difference imagery with pre-f ire TC wetness had an overall accuracy of 68%, that of the post-burn SI was 63%, and that from aerial photo interpretation was 56%. Before the burn, landscape matrix was closed mature/old-growth. After the burn, the early seral/rock stage expanded, the open mature/old-growth stage was created, and the closed mature/old-growth was reduced and fragmented. Thus, overall habitat diversity and edge increased, but interior habitat decreased. Also, patches of early seral/rock were more variable in size and complex in shape than staggered setting clearcuts on public lands. Title: Analyzing fire mosaics in temperate coniferous forests with GIS and remote sensing Author: Kushla, John D. This investigation on fire mosaics addressed several aspects: (1) quantifying the role of terrain variables in fire-related mortality and historical mean fire return interval (MFRI), (2) comparing post-burn Landsat Thematic Mapper (TM) imagery, TM difference imagery, and aerial photo interpretation to map forest survival after wildfire, and (3) to describe and discuss wildfire effects on successional stage patterns and wildlife habitat. The two study sites were located on the Willamette National Forest in the Oregon Cascades. The Warner Creek burn was the location of a 1991 wildfire covering 3669 ha; the Upper McKenzie site was the location of ecological and historical fire studies. Historical MFRI, terrain, and vegetation data were input into a geographical information system. Random sampling was conducted on all layers, and was also used to ground truth forest survival, primarily with aerial photography. Relationships of terrain to forest survival and historical MFRI were analyzed with regression. Regression was also used to model forest survival with TM data. Error matrices were used to compare classified TM data and aerial photo interpretation in mapping survival. At both sites, terrain variables accounted for more variation in forest survival (12-62%) or historical MFRI (4.8-21.9%) within individual physiographic areas, than across the respective study areas. Moreover, the significant topographic variables differed among individual physiographic areas. Regressions of TM band transformations were used to evaluate forest survival. The TM difference imagery with stratification by pre-f ire tasseled cap (TC) wetness explained 75% of the variation in live canopy ratio, and post-burn TM Structural Index (SI) accounted for 72%. Classification of the TM difference imagery with pre-f ire TC wetness had an overall accuracy of 68%, that of the post-burn SI was 63%, and that from aerial photo interpretation was 56%. Before the burn, landscape matrix was closed mature/old-growth. After the burn, the early seral/rock stage expanded, the open mature/old-growth stage was created, and the closed mature/old-growth was reduced and fragmented. Thus, overall habitat diversity and edge increased, but interior habitat decreased. Also, patches of early seral/rock were more variable in size and complex in shape than staggered setting clearcuts on public lands. Close

• 93. [Article] Areal distribution, change, and restoration potential of wetlands within the lower Columbia River riparian zone, 1948-1991

  The lower Columbia River (LCR) riparian zone is rich in habitat diversity. However, the natural beauty and species diversity along the river have increasingly become affected by human activity. This study ...

  Citation × Citation Citation Abstract Copy Title: Areal distribution, change, and restoration potential of wetlands within the lower Columbia River riparian zone, 1948-1991 Author: Allen, Tracy Hunter The lower Columbia River (LCR) riparian zone is rich in habitat diversity. However, the natural beauty and species diversity along the river have increasingly become affected by human activity. This study quantifies the areal extent and degree of wetlands change and associated causes along the LCR over the past 44 years. This research examines the distribution of wetland types and their patterns of change, developing regional models which rank areas most conducive to potential wetland recovery or restoration efforts. The length of the study area totals 234 river kilometers, from the mouth of the Columbia River to Bonneville Dam. The width includes the active channel and an approximately three-kilometer swath on either side of the river. Aerial photography was the primary means for interpreting historical extent of wetlands, using five photo dates (1948, 1961, 1973, 1983, and 1991), based upon their time interval, coverage, and photo quality. For each photo throughout the entire study site, land uses and wetland habitats greater than one hectare were identified and classified. Each classified polygon was digitized and spatially analyzed using a Geographic Information System. This study indicates that wetland habitats which were once contiguously draped upon the linear features of the river are decreasing in size and becoming fragmented. There have been both increases and decreases in specific wetland habitat areas which vary by river reach, even though wetlands have diminished overall. The estuarine section of the LCR experienced a 25% net decrease in wetland area between 1948 and 1991, while the riverine tidal section fostered a 1% increase. The riverine lower perennial section sustained the greatest loss of wetlands, which decreased by 37%. Causes for wetland losses in the estuarine section were largely related to in-water activities, such as channelization, while the causes for declines in the riverine lower perennial section were correlated with rapid urbanization. Wetland increases in the riverine tidal section were generally influenced by significant growth in palustrine and forested wetlands associated with the establishment of wildlife refuges and the incremental increase of upstream flood storage capacity. This research provides a template for identifying degraded or displaced wetlands. Through the use of a GIS, each historical wetland was ranked in either low, moderate, or high categories for restoration potential. GIS technology permits focused, sequentially-refined queries to identify potential restoration or recovery sites. In the estuarine section, 74 historical wetland sites were ranked high for restoration potential, while in the riverine tidal and riverine lower perennial sections, there were 178 and 105, respectively. Overall, these sites represent only 25% of the area occupied by wetlands in 1948. While this study advocates restoration potential, restoration is not a surrogate for responsible ecosystem-wide stewardship of the riparian zone. Restoration will not succeed unless degrading factors are mitigated or eliminated. Title: Areal distribution, change, and restoration potential of wetlands within the lower Columbia River riparian zone, 1948-1991 Author: Allen, Tracy Hunter The lower Columbia River (LCR) riparian zone is rich in habitat diversity. However, the natural beauty and species diversity along the river have increasingly become affected by human activity. This study quantifies the areal extent and degree of wetlands change and associated causes along the LCR over the past 44 years. This research examines the distribution of wetland types and their patterns of change, developing regional models which rank areas most conducive to potential wetland recovery or restoration efforts. The length of the study area totals 234 river kilometers, from the mouth of the Columbia River to Bonneville Dam. The width includes the active channel and an approximately three-kilometer swath on either side of the river. Aerial photography was the primary means for interpreting historical extent of wetlands, using five photo dates (1948, 1961, 1973, 1983, and 1991), based upon their time interval, coverage, and photo quality. For each photo throughout the entire study site, land uses and wetland habitats greater than one hectare were identified and classified. Each classified polygon was digitized and spatially analyzed using a Geographic Information System. This study indicates that wetland habitats which were once contiguously draped upon the linear features of the river are decreasing in size and becoming fragmented. There have been both increases and decreases in specific wetland habitat areas which vary by river reach, even though wetlands have diminished overall. The estuarine section of the LCR experienced a 25% net decrease in wetland area between 1948 and 1991, while the riverine tidal section fostered a 1% increase. The riverine lower perennial section sustained the greatest loss of wetlands, which decreased by 37%. Causes for wetland losses in the estuarine section were largely related to in-water activities, such as channelization, while the causes for declines in the riverine lower perennial section were correlated with rapid urbanization. Wetland increases in the riverine tidal section were generally influenced by significant growth in palustrine and forested wetlands associated with the establishment of wildlife refuges and the incremental increase of upstream flood storage capacity. This research provides a template for identifying degraded or displaced wetlands. Through the use of a GIS, each historical wetland was ranked in either low, moderate, or high categories for restoration potential. GIS technology permits focused, sequentially-refined queries to identify potential restoration or recovery sites. In the estuarine section, 74 historical wetland sites were ranked high for restoration potential, while in the riverine tidal and riverine lower perennial sections, there were 178 and 105, respectively. Overall, these sites represent only 25% of the area occupied by wetlands in 1948. While this study advocates restoration potential, restoration is not a surrogate for responsible ecosystem-wide stewardship of the riparian zone. Restoration will not succeed unless degrading factors are mitigated or eliminated. Close

• 94. [Article] Gravitational Waves and the Laser Interferometer Space Antenna (LISA) and “Lab on a Chip”

  Improvements on the charge control measurements of the torsion pendulum, electron gun, and autocollimator system were conducted at the University of Washington in preparation for the fabrication of the ...

  Citation × Citation Citation Abstract Copy Title: Gravitational Waves and the Laser Interferometer Space Antenna (LISA) and “Lab on a Chip” Author: Gifford, Jessica Improvements on the charge control measurements of the torsion pendulum, electron gun, and autocollimator system were conducted at the University of Washington in preparation for the fabrication of the final prototype of the Laser Interferometer Space Antenna (LISA) gravitational wave detector for NASA. One main cause of transient forces on LISA is solar charges in space that can cause unwanted torque on the test masses. Using a torsion pendulum as a geometric equivalent of the test masses, charge control measurements were conducted by producing a sinusoidal curve of the charge. The pendulum could be negatively or positively charged by an electron gun or a UV LED by increments as small as a pico-coulomb. The average charging for the UV LED is 3.5*10⁻¹⁴ C/s, and electron gun is -4.4*10⁻¹⁴ C/s, which allows for very precise control. Photocurrent of the UV LED and electron gun were measured by fabricating two new electron guns, one including an Einzel lens. Preliminary results showed that a current leakage powering the UV LED was a major source of error. To compensate for this error a battery system was built to power the UV LED separately from the electron gun. Subsequent results showed that, even with the battery improvement, no difference in current could be measured. To cut down on further current leakage a data acquisition program (DAQ) was designed to electronically control the power of the system. The results from varying the voltage using the DAQ, showed that the photocurrent linearly increases and asymptotically approaches a maximum current. However, by moving the battery system, the current jumps drastically, which means that the production of photocurrent is yet to be conclusive. Finally, the autocollimator was used to measure the torque on the pendulum with heterodyne interferometry. A system of thermometers was fabricated to measure the temperature inside and outside the autocollimating system. It was shown that the thermal noise fluctuation is 0.14C° in the system. It is hypothesized that this fluctuation can be eliminated which will be enough to improve the sensitivity of the autocollimator by an order of magnitude. “Lab on a Chip” - Prototypes of a “Lab on a Chip” system that can make the sensors in situ in the device and then directly measure changes within a cell could greatly aid biologist in investigating changes within a variety of cells. At Oregon State University, an experimental setup was designed to trap and excite fluorescence of a particle or nano-sensor with and without a microfluidic device. An excitation laser at 532 nm and an optical trapping laser at 800 nm were used. The power of the excitation laser must be ~10 mW, which is low enough to cause minimal photo bleaching of the particles, and the power of the trapping laser must be ~5 mW for a 1 μm particle. One particle was trapped at a time by using confocal setting and aligning both lasers to hit the sample on the inverted microscope to within a few nano meters. Proof of concept of the setup was then conducted using commercial Fluorospheres. The spectrum measured by this design matches the theoretical spectra provided by the particles’ manufacturer demonstrating that the experimental design performs to specifications. Measurements were taken on the nano-sensors made by the collaborators at the chemistry department to verify that the setup is compatible with the new particles. First using only the excitation laser to excite and trap the sensors, different fluorescence peaks were measured for two samples of particles in pH ~2 and ~6 solutions. Because of photo bleaching, the behavior of the spectra are indistinguishable from that of deprotonated peaks, however there was notable difference between the particles. The trapping laser was then reintroduced and verified that fluorescence measurements of a nano-sensor can be obtained with this experimental design. Two other experiments were conducted, which confirm the proof of concept of this experimental design. Fluorescence data of K+ ion sensitive sensors, which switch from deprotonated peaks, to protonated, using widefield excitation, was measured. This shows that the sensors behave as expected. Also, using this experimental technique developed, the setup was able to trap and measure the fluorescence of pH 2 and pH 7.5 sensors inside a microfluidic trap, and that the correct measurements can be taken with the setup even within a microfluidic trap. Title: Gravitational Waves and the Laser Interferometer Space Antenna (LISA) and “Lab on a Chip” Author: Gifford, Jessica Improvements on the charge control measurements of the torsion pendulum, electron gun, and autocollimator system were conducted at the University of Washington in preparation for the fabrication of the final prototype of the Laser Interferometer Space Antenna (LISA) gravitational wave detector for NASA. One main cause of transient forces on LISA is solar charges in space that can cause unwanted torque on the test masses. Using a torsion pendulum as a geometric equivalent of the test masses, charge control measurements were conducted by producing a sinusoidal curve of the charge. The pendulum could be negatively or positively charged by an electron gun or a UV LED by increments as small as a pico-coulomb. The average charging for the UV LED is 3.5*10⁻¹⁴ C/s, and electron gun is -4.4*10⁻¹⁴ C/s, which allows for very precise control. Photocurrent of the UV LED and electron gun were measured by fabricating two new electron guns, one including an Einzel lens. Preliminary results showed that a current leakage powering the UV LED was a major source of error. To compensate for this error a battery system was built to power the UV LED separately from the electron gun. Subsequent results showed that, even with the battery improvement, no difference in current could be measured. To cut down on further current leakage a data acquisition program (DAQ) was designed to electronically control the power of the system. The results from varying the voltage using the DAQ, showed that the photocurrent linearly increases and asymptotically approaches a maximum current. However, by moving the battery system, the current jumps drastically, which means that the production of photocurrent is yet to be conclusive. Finally, the autocollimator was used to measure the torque on the pendulum with heterodyne interferometry. A system of thermometers was fabricated to measure the temperature inside and outside the autocollimating system. It was shown that the thermal noise fluctuation is 0.14C° in the system. It is hypothesized that this fluctuation can be eliminated which will be enough to improve the sensitivity of the autocollimator by an order of magnitude. “Lab on a Chip” - Prototypes of a “Lab on a Chip” system that can make the sensors in situ in the device and then directly measure changes within a cell could greatly aid biologist in investigating changes within a variety of cells. At Oregon State University, an experimental setup was designed to trap and excite fluorescence of a particle or nano-sensor with and without a microfluidic device. An excitation laser at 532 nm and an optical trapping laser at 800 nm were used. The power of the excitation laser must be ~10 mW, which is low enough to cause minimal photo bleaching of the particles, and the power of the trapping laser must be ~5 mW for a 1 μm particle. One particle was trapped at a time by using confocal setting and aligning both lasers to hit the sample on the inverted microscope to within a few nano meters. Proof of concept of the setup was then conducted using commercial Fluorospheres. The spectrum measured by this design matches the theoretical spectra provided by the particles’ manufacturer demonstrating that the experimental design performs to specifications. Measurements were taken on the nano-sensors made by the collaborators at the chemistry department to verify that the setup is compatible with the new particles. First using only the excitation laser to excite and trap the sensors, different fluorescence peaks were measured for two samples of particles in pH ~2 and ~6 solutions. Because of photo bleaching, the behavior of the spectra are indistinguishable from that of deprotonated peaks, however there was notable difference between the particles. The trapping laser was then reintroduced and verified that fluorescence measurements of a nano-sensor can be obtained with this experimental design. Two other experiments were conducted, which confirm the proof of concept of this experimental design. Fluorescence data of K+ ion sensitive sensors, which switch from deprotonated peaks, to protonated, using widefield excitation, was measured. This shows that the sensors behave as expected. Also, using this experimental technique developed, the setup was able to trap and measure the fluorescence of pH 2 and pH 7.5 sensors inside a microfluidic trap, and that the correct measurements can be taken with the setup even within a microfluidic trap. Close

• 95. [Article] Effect of sensory properties and health information on consumer acceptance and purchase of colorful fresh market potatoes

  Potato varieties characterized by non-conventional skin and flesh colors (purple, red, yellow) have the potential to revitalize consumer demand for fresh market potatoes because of their unique appearance ...

  Citation × Citation Citation Abstract Copy Title: Effect of sensory properties and health information on consumer acceptance and purchase of colorful fresh market potatoes Author: Wechsler, Linda J. Potato varieties characterized by non-conventional skin and flesh colors (purple, red, yellow) have the potential to revitalize consumer demand for fresh market potatoes because of their unique appearance and health benefits. Red and purple potatoes contain anthocyanins, which are flavonoids responsible for red, blue, and purple pigments in plants. Yellow potatoes contain carotenoids, which are xanthophylls responsible for orange and yellow pigments in plants. Both anthocyanins and carotenoids are antioxidants that benefit human health. The objective of this thesis research was to investigate consumer acceptance of colorful fresh market potato varieties and to understand the effect of health information on purchase intent. This thesis research was divided into three studies, preceded by a literature review. The literature review summarized research linking raw tuber characteristics to the culinary quality of fresh market potatoes. Specific compounds, genes, and processes affecting potato appearance, flavor, and texture were reviewed. In the first study, consumer attitudes and opinions about colorful fresh market potatoes were investigated using four focus group sessions with a total of 37 participants. Five colorful potato varieties were shown to participants. Purchase intent for each variety was marked on an anchored line scale after: 1) seeing and handling the raw uncut potato, 2) seeing a photo of the raw potato cut in half, 3) seeing a photo of the potato cooked (boiled) and cut in half, and 4) after receiving health information describing antioxidant benefits. Reactions to colorful potato varieties were mixed. Health information had a greater impact on purchase intent than the photos of the raw and cooked potatoes. Purchase intent was also influenced by positive and negative associations with appearance, concerns about genetic engineering, tampering, and chemicals, preparation and presentation considerations, point of sale, family acceptance, and anticipated flavor. In the second study, a consumer acceptance test with 222 participants evaluated six colorful fresh market potato varieties alongside a commonly available variety, the Yukon Gold. Participants rated liking of overall appearance, color, size, and shape for raw uncut potatoes on a 9-point category scale. Participants tasted the potatoes boiled and rated liking of cooked appearance, flavor, and texture on a 9-point category scale. Participant comments describing what they liked and/or disliked about each raw and cooked potato were also captured. For color, yellow and red varieties were accepted over purple varieties. For shape and size, large and round varieties were accepted over small, elongated varieties. Bimodal hedonic score distributions were observed for purple color, small size, and elongated shape. Consumer comments revealed that a uniform raw and cooked appearance, a distinct flavor with no undesirable aftertaste, and a smooth, firm, and consistent texture were all desirable characteristics. In the third study, the effect of health information on purchase intent for colorful fresh market potatoes was investigated. Participants either received no information, a simple statement, or a detailed statement about antioxidants in colorful potatoes. After reading the information, participants rated purchase intent on a 5-point category scale at a low, medium, and high price. The effect of antioxidant information on the probability of purchase for red and purple potatoes was compared to yellow potatoes. The impact of hedonic rating, price, gender, age, education, income, usage frequency, health interest, food interest, and antioxidant knowledge were also investigated. High hedonic ratings and interest in food had a positive effect on purchase intent for all potatoes. High price had a negative effect on purchase intent for all potatoes. Antioxidant information and interest in health had a positive effect on purchase intent for red and purple potatoes. Age had a negative effect on purchase intent for red and purple potatoes. An advanced degree of education had a negative effect on purchase intent for yellow potatoes. Title: Effect of sensory properties and health information on consumer acceptance and purchase of colorful fresh market potatoes Author: Wechsler, Linda J. Potato varieties characterized by non-conventional skin and flesh colors (purple, red, yellow) have the potential to revitalize consumer demand for fresh market potatoes because of their unique appearance and health benefits. Red and purple potatoes contain anthocyanins, which are flavonoids responsible for red, blue, and purple pigments in plants. Yellow potatoes contain carotenoids, which are xanthophylls responsible for orange and yellow pigments in plants. Both anthocyanins and carotenoids are antioxidants that benefit human health. The objective of this thesis research was to investigate consumer acceptance of colorful fresh market potato varieties and to understand the effect of health information on purchase intent. This thesis research was divided into three studies, preceded by a literature review. The literature review summarized research linking raw tuber characteristics to the culinary quality of fresh market potatoes. Specific compounds, genes, and processes affecting potato appearance, flavor, and texture were reviewed. In the first study, consumer attitudes and opinions about colorful fresh market potatoes were investigated using four focus group sessions with a total of 37 participants. Five colorful potato varieties were shown to participants. Purchase intent for each variety was marked on an anchored line scale after: 1) seeing and handling the raw uncut potato, 2) seeing a photo of the raw potato cut in half, 3) seeing a photo of the potato cooked (boiled) and cut in half, and 4) after receiving health information describing antioxidant benefits. Reactions to colorful potato varieties were mixed. Health information had a greater impact on purchase intent than the photos of the raw and cooked potatoes. Purchase intent was also influenced by positive and negative associations with appearance, concerns about genetic engineering, tampering, and chemicals, preparation and presentation considerations, point of sale, family acceptance, and anticipated flavor. In the second study, a consumer acceptance test with 222 participants evaluated six colorful fresh market potato varieties alongside a commonly available variety, the Yukon Gold. Participants rated liking of overall appearance, color, size, and shape for raw uncut potatoes on a 9-point category scale. Participants tasted the potatoes boiled and rated liking of cooked appearance, flavor, and texture on a 9-point category scale. Participant comments describing what they liked and/or disliked about each raw and cooked potato were also captured. For color, yellow and red varieties were accepted over purple varieties. For shape and size, large and round varieties were accepted over small, elongated varieties. Bimodal hedonic score distributions were observed for purple color, small size, and elongated shape. Consumer comments revealed that a uniform raw and cooked appearance, a distinct flavor with no undesirable aftertaste, and a smooth, firm, and consistent texture were all desirable characteristics. In the third study, the effect of health information on purchase intent for colorful fresh market potatoes was investigated. Participants either received no information, a simple statement, or a detailed statement about antioxidants in colorful potatoes. After reading the information, participants rated purchase intent on a 5-point category scale at a low, medium, and high price. The effect of antioxidant information on the probability of purchase for red and purple potatoes was compared to yellow potatoes. The impact of hedonic rating, price, gender, age, education, income, usage frequency, health interest, food interest, and antioxidant knowledge were also investigated. High hedonic ratings and interest in food had a positive effect on purchase intent for all potatoes. High price had a negative effect on purchase intent for all potatoes. Antioxidant information and interest in health had a positive effect on purchase intent for red and purple potatoes. Age had a negative effect on purchase intent for red and purple potatoes. An advanced degree of education had a negative effect on purchase intent for yellow potatoes. Close

• 96. [Article] Stop the spread of sudden oak death

  Revised January 2012. Revised March 2013. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog

  Citation × Citation Citation Abstract Copy Title: Stop the spread of sudden oak death Author: Shaw, David Carl, 1955-, Kanaskie, Alan, Oregon State University. Extension Service Revised January 2012. Revised March 2013. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Title: Stop the spread of sudden oak death Author: Shaw, David Carl, 1955-, Kanaskie, Alan, Oregon State University. Extension Service Revised January 2012. Revised March 2013. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Close

• 97. [Article] Stop the spread of sudden oak death

  Revised December 2009. Revised January 2012. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog

  Citation × Citation Citation Abstract Copy Title: Stop the spread of sudden oak death Author: Goheen, Ellen Michaels, Shaw, David Carl, 1955-, Oregon State University. Extension Service Revised December 2009. Revised January 2012. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Title: Stop the spread of sudden oak death Author: Goheen, Ellen Michaels, Shaw, David Carl, 1955-, Oregon State University. Extension Service Revised December 2009. Revised January 2012. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Close

• 98. [Article] Silver scurf management in potatoes

  Published August 2007. Revised April 2013. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog

  Citation × Citation Citation Abstract Copy Title: Silver scurf management in potatoes Author: Hamm, Philip B., Olsen, Nora, Nolte, Phillip, Oregon State University. Extension Service, Miller, Jeff S., Johnson, Dennis A. (Dennis Allen) Published August 2007. Revised April 2013. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Title: Silver scurf management in potatoes Author: Hamm, Philip B., Olsen, Nora, Nolte, Phillip, Oregon State University. Extension Service, Miller, Jeff S., Johnson, Dennis A. (Dennis Allen) Published August 2007. Revised April 2013. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Close

• 99. [Article] OSU Women in Development: Nepal Exchange 1995-1997

  This record includes three files including interview notes and photos from Roberta Hall's 1997 visit to Nepal and an annotated bibliography.

  Citation × Citation Citation Abstract Copy Title: OSU Women in Development: Nepal Exchange 1995-1997 Author: Hall, Roberta L. This record includes three files including interview notes and photos from Roberta Hall's 1997 visit to Nepal and an annotated bibliography. Title: OSU Women in Development: Nepal Exchange 1995-1997 Author: Hall, Roberta L. This record includes three files including interview notes and photos from Roberta Hall's 1997 visit to Nepal and an annotated bibliography. Close

• 100. [Article] Preventing herbicide drift and injury to grapes

  Published March 2004. Revised February 2014. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog

  Citation × Citation Citation Abstract Copy Title: Preventing herbicide drift and injury to grapes Author: Corp, Mary K., Ball, Daniel A. (Daniel Allen), 1954-, Oregon State University. Extension Service, Dami, Imed Published March 2004. Revised February 2014. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Title: Preventing herbicide drift and injury to grapes Author: Corp, Mary K., Ball, Daniel A. (Daniel Allen), 1954-, Oregon State University. Extension Service, Dami, Imed Published March 2004. Revised February 2014. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Close