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Soils of Willamette series and their utilization
Get PDFPublished December 1928. 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/catalo
Liming western Oregon soils
Get PDFPublished December 1928. 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/catalo
Regulations of the secretary of agriculture for the occupancy, use, protection, and administration of the national forests
Get PDFGerald W. Williams Collectio
Development of new analytical methods for aroma analysis and investigation of impact of native yeasts on wine aroma
Get PDFThree analytical methods for determination of aroma compounds in alcoholic beverages were developed and validated. These methods are sensitive and reliable that can be applied to analyze volatile phenols, stale aldehydes as well as some highly volatile aromas in alcoholic beverages. In the first study, an ethylene glycol (EG) polydimethylsiloxane (PDMS) copolymer based stir bar sorptive extraction (SBSE)-GC–MS method was developed for the analysis of volatile phenols in alcoholic beverages. Parameters affecting extraction efficiency were studied including ionic strength, pH, extraction time, ethanol content and nonvolatile matrix. Good correlation coefficients with R2 in the range of 0.994–0.999 were obtained for volatile phenol concentration of 5–500 µg L. Recovery for all phenols were from 95.7% to 104.4% in a beer matrix and 81.4% to 97.6% in a wine matrix. The method had a standard deviation less than 5.8% for all volatile phenols. The limit of quantification (LOQs) in beer samples was lower than 3μg L. In the second study, a simple, fast and reliable method was validated, in which headspace sampling was used in combination with gas chromatography-flame ionization detector (GC-FID) for quantifying the most abundant and highly volatile compounds in alcoholic beverages. The linearity for all the compounds covered 2 orders of magnitude with correlation coefficients (R2) between 0.9993-0.9996. The recovery ranged from 92.7%-99.9% in beer samples and 90.9%-117% in wine samples. The repeatability of this method was satisfactory with relative standard deviation of 2.9%-4.7%. The LOQ and LOD were much lower than the reported concentrations in alcoholic beverage including beer and wine.In the third study, a sensitive method for the determination of stale aldehydes in alcoholic beverages has been developed. Aldehydes were derivatized with O-(2, 3, 4, 5, 6-pentafluorobenzyl) hydroxylamine (PFBHA) in solution and the corresponding oximes were extracted using a DVB PDMS SPME fiber and quantified by GC-MS-SIM mode. It is shown that acidic pH and lower temperature would favor the sensitivity of aldehyde derivatives. Meanwhile by using SIM mode, the background can be eliminated a lot and the limit of quantification reached as low as 0.01μg L (0.1ppb) for most compounds, and the linearity is up to 100μg L with R2 in the range 0.993–0.999.In the fourth study, 5 out of 12 yeasts that isolated from a pre-fermentation cold maceration (9°C) of Pinot noir grapes, were confirmed with β-glucosidase activity, namely Metschnikowia pulcherrima, Hanseniaspora uvarum, Lachancea thermotolerans, and two isolates of Saccharomyces cerevisiae. These yeasts were inoculated in Pinot noir grapes sterilized by high hydrostatic pressure, individually or mixed. Pre-fermentation cold maceration (9°C) was performed followed by alcoholic fermentation conducted by Saccharomyces cerevisiae RC212 at 27°C. Aroma analysis of wine by solid-phase microextraction-GC-MS demonstrated that the presence of the different yeast species during the pre-fermentation cold maceration could alter the volatile aroma composition of wine. The yeasts in pre-fermentation cold maceration altered the concentrations of ethyl esters, branch-chained esters, higher alcohols and monoterpenes. In the fifth study, one of the two Saccharomyces cerevisiae isolates with high β-glucosidase activity from previous work was used to further investigate the impact of pre-fermentation cold maceration on Gewürztraminer wine aroma. A commercial yeast was used in comparison where no cold maceration treatment was performed. The quantification results of aroma compounds showed that pre-fermentation cold-maceration did not significantly affect aroma profile of Gewürztraminer wine. OSU yeast isolate produced comparable amount of terpene alcohols as yeast Vin13, a commercial yeast strain known to produce good aromatic white wine. However, OSU yeast isolate produced dramatically higher concentration of 4-vinylphenol and 4-vinylguaiacol, which give spicy, clove-like aroma, a major character of Gewürztraminer wines. The results were highly correlated to the sensory evaluation. OSU yeast isolate is a good candidate in fermenting aromatic white wine. Pre-fermentation cold maceration is not essential in making white wines.In the sixth study, glycosides precursors extracted from pinot noir grape have been reconstituted with a synthetic must. The must is fermented by yeasts belonging to previously isolated different genera. Fermentation was allowed to take place for 48 hours. The fermented solutions were analyzed by headspace solid phase microextraction gas chromatography–mass spectrometry (HS-SPME-GC-MS) to determine the aroma composition. The results shows that the yeast genus exerts a critical influence on the levels of most varietal aroma compounds. The aroma produced from precursors such as norisoprenoids and terpenols has been affected.Keywords: Pinot Noir, Yeast, Wine, Arom
Visualization and analysis of sensor data for detecting microclimate cold air pools
Get PDFCold air pools are spatiotemporal phenomena that occur when cold air from higher elevations roll down the slope to accumulate in lower elevations. Behaviors like this lead to microclimate anomalies such as the city of Corvallis (Oregon) experiencing persistent cold weather even on a sunny day. We analyze multivariate temperature time-series data and associated covariates from about 160 sensors from the HJ Andrews Research Forest (Oregon) through visualization and modeling to study this phenomenon. We develop detectors to localize cold air pools in both time and space, and carry out simulation studies to assess their performance under different microclimatic and sensor-performance conditions.Keywords: Polynomial regression, Cold Air Pools, Piecewise Linear Regression, Machine Learnin
Investigating Timescales of Resurgence at Large Calderas: Post-74 ka Activity at Toba Caldera, Sumatra, Indonesia
No full textThe Toba Caldera Complex is the youngest resurgent caldera in the last 100 kyrs, formed from four overlapping eruptions starting 1.2 Myrs ago. The last caldera-forming eruption, the Youngest Toba Tuff eruption, occurred ~74 kyrs ago, emitting 2800 km3 of ash and pumice into the atmosphere and forming the caldera outline seen today. The amount of ejecta released into the atmosphere potentially affected the global climate and regional human evolution. The youth of this caldera system has made it the perfect natural laboratory for investigating resurgence, the last stage in the caldera cycle, associated with volcanic effusions and structural deformation and uplift. Organic-rich sediments found on the uplifted caldera floor provide a well-preserved and detailed history of the resurgent uplift, while lava extrusions along faults running through and around the caldera provide geological context for the initiation of resurgent activity at Toba Caldera. New data reveal details of the post-caldera history at the Earth’s youngest resurgent supervolcano, Toba caldera in Sumatra. Resurgence after the caldera-forming ∼74 kyrs ago Youngest Toba Tuff eruption uplifted the caldera floor as a resurgent dome, Samosir Island, capped with 100 m of lake sediments. 14C age data from the uppermost datable sediments reveal that Samosir Island was submerged beneath lake level (∼900 m a.s.l) at 33 kyrs ago. Since then, Samosir experienced 700 m of uplift as a tilted block dipping to the west. 14C ages and elevations of sediment along a transect of Samosir reveal that minimum uplift rates were ∼5.6 cm year from ∼33.7 to 22.5 kyrs ago, but diminished to ∼0.7 cm year after 22.5 kyrs ago.
Localised uplift activity continued along the eastern coast of Samosir associated with volcanic effusions, with 14C ages of sediments found blanketing lava domes as young as ~2.7 kyrs ago, producing localized uplift rates of ~1.9 cm yr. Zircon U-Th crystallization and (U-Th) He ages reveal resurgence commenced at 69.7 ± 4.5 kyrs ago progressing westward across the caldera, as reflected by post-caldera effusive lava eruptions and uplifted lake sediment. Previous geochronology for four of these lava dome localities (North Samosir, Tuk Tuk Samosir, North Pardepur, South Pardepur) by combined U-Th-disequilibrium (U-Th) He zircon geochronology yielded eruption ages ranging from 69.7 ± 4.5 kyrs ago to 56.9 ± 3.9 kyrs ago, implying resurgent volcanic activity started almost immediately after the climactic eruption and continued for ~20,000 years. 40Ar 39Ar ages from sanidine and plagioclase feldspar crystals from the same lava domes have returned ages that are contemporaneous with the climactic eruption, between 74.3 ± 0.4 and 71.4 ± 8.2 kyrs ago for North Samosir, Tuk Tuk Samosir, and South Pardepur, with only North Pardepur showing a substantially younger 40Ar 39Ar crystallization age of 23.6 ± 9.8 kyrs ago. These ages overlap with the (U-Th) He ages, but the younger error weighted average (U-Th) He eruption ages imply that the process of resurgence is more complex. Using eruption temperatures and a simple argon diffusion model, the difference between the weighted mean (U-Th) He age and stacked plateau 40Ar 39Ar ages can be explained by a difference in closure temperatures between argon and helium. Sanidine and plagioclase feldspar crystals from three lava domes record the YTT eruption age and are interpreted to be antecrysts that remained in the remnant magma system below argon closure temperature (Tc) in sanidine plagioclase (350°C). In contrast, the younger North Pardepur lava dome 40Ar 39Ar inverse isochron plagioclase age of 47.9 ± 11.1 kyrs ago overlaps with the (U-Th) He age, implying that plagioclase crystals are either autocrysts, formed during the eruption of the North Pardepur dome, or YTT antecrysts that have been reset due to their host magma remaining above argon Tc for >700 yrs. Matrix glass analyses represented on the quartz-albite-orthoclase (Qz-Ab-Or) ternary plot indicate that the Samosir dome magmas equilibrated over a deeper range of pressures (200-50 MPa) than the YTT (100-50 MPa), while the Pardepur dome magmas record the lowest pressures (50-0.1 MPa). Fault and drainage analysis of the resurgent dome shows that the southern half of Samosir Island is much more dissected than the northern half of the island. Drainage basins in the south are much more developed, with very little sediment cover left and basement rock observed to be exposed in some areas. Using drainage basin analysis tools in ArcGIS and the Geomorph Tools program in Matlab, the stream networks were analysed and channel profiles were created. Combining the identified locations of knickpoints along these channel profiles with assumed erodibility paramters, the minimum amount of time needed for the drainage basins to develop was calculated. Based on these calculations, drainage basins in the north and south took the same amount of time to develop. This means that the difference in drainage development is a result of another factor. One possible explanation is that pre-existing faults may underlie the thick intracaldera YTT deposit on the southern half of Samosir. These faults may have been from the previous half of the OTT resurgent dome, Uluan, which Samosir has appeared to take the place of. Pre-existing faults could have resulted in areas of weakness that were exploited during drainage basin development, thus making the southern drainage basins develop faster than the northern drainage basins. A more detailed study is required, however, to fully develop this potential hypothesis. A major active stratovolcano north of Toba, Sinabung, shows strong geochemical kinship with Toba, through 87Sr 86Sr isotopes, whole rock chemistry, and 238U-230Th disequilibrium ages of zircons from recent eruption products. This suggests that Toba’s climactic magma reservoir, which was tapped during resurgence, may extend beneath Sinabung and is being tapped during current Sinabung eruptions. This implies that resurgence at the Toba Caldera system may have continued as eruptions at Sinabung.Keywords: Resurgence, Toba Caldera, Timescales, Indonesia, Geochronology, Caldera Cycl
Characterizing the Plant-Associated Symbionts, Rhodococcus and Agrobacterium
Get PDFSymbioses are a spectrum of interactions between organisms living in closeassociation. These intimate interactions range from mutualism, in which bothorganisms benefit, to parasitism, where one organism benefits at the expense ofthe other. Horizontal gene transfer is the acquisition of genes independent ofvertical transmission and demonstrably promotes the transition of bacteria fromfree-living to symbiotic. The horizontal acquisition of plasmids allows members ofthe Agrobacterium and Rhodococcus genera to cause disease to plants, many ofwhich are important for the ornamental plant industry. Therefore, the accurate andrapid diagnosis of these pathogens is critical for management, and failure toproperly diagnose or respond can result in severe economic losses. Indeed, somediagnostic methods have the potential to be misleading and assign nonpathogenicRhodococcus as the causative agents of disease. I test the hypothesis thathorizontal gene transfer can elicit the transition of Rhodococcus between beneficialand pathogenic states.I demonstrate that most Rhodococcus isolates are beneficial and promotechanges to the root system, such as those that are frequently associated with plantgrowth promoting bacteria. I further demonstrate that beneficial Rhodococcusstrains transition to pathogens upon the acquisition of a virulence plasmid. Theseare virulent on plants and can cause disease symptoms to both roots and aerialportions of plants. Lastly, I develop reagents for use in a sensitive and specificnovel diagnostic test that accelerates identification of pathogenic strains ofRhodococcus and Agrobacterium. This work highlights the fluidity in the evolutionof plant-associated bacteria and how transitions in symbiotic state can confounddiagnosis.Keywords: Rhodococcus, Symbiosis, Detection, Agrobacteriu
Trends in streamflow above and below dams across the Columbia River basin from 1950 to 2012 : assessing sub-basin sensitivity
No full textClimate change, combined with population growth, is expected to exacerbate water scarcity globally. In the Columbia River basin (CRB), streamflow is managed for multiple objectives with a network of dams and reservoirs distributed throughout the basin that may mitigate climate change effects on water scarcity. This study quantified trends in daily streamflow from 1950-2012 in 28 pairs of gages above and below dams in the CRB, including the U.S. and Canada. Each gage pair consisted of an above-dam gage that is primarily forested and has little apparent human disturbance and minimal flow regulation or diversions, combined with a below-dam gage immediately downstream of a major dam and reservoir. Monthly streamflow and precipitation for a total of 59 sites was correlated with monthly indices of the Pacific Decadal Oscillation (PDO), the Northern Pacific Index (NPI), the Pacific North America pattern (PNA), and the 700-millibar wind speeds (u700) using Pearson's r. Long-term trends and patterns in daily streamflow and climate data were estimated using linear regression, the Mann-Kendall test, and wavelet analysis. Streamflow was generally weakly correlated with NPI, PNA, and PDO, while positively correlated with upper elevation wind speed at low elevations during wet months. Fewer than half of above-dam gages in the CRB have experienced increasing trends in daily streamflow from mid-March to the beginning of May over the period 1950 to 2012, whereas a majority has experienced decreasing trends from the middle of May to the middle of October. These trends in above-dam basins are consistent with trends expected from climate change, but they also may be affected by legacies of past forest harvest or wildfire. Below dams, reservoir management appears to have overwritten the signal of earlier snowmelt, except in the Boise sub-basin, but long-term declines in late summer flows were evident at half of below-dam sites. Declining summer flows below dams were attributable to a variety of factors, including changes in reservoir management as well as reservoir management that propagates signals from above dam catchments, such as climate change or forest-harvest legacy effects on streamflow. There have been very few significant changes in annual flow volume throughout the basin, and these streamflow trends represent a small percentage of annual flow volume; thus, observed trends appear to be shifts in timing rather than shifts in the annual water balance. The magnitude of 60-yr declines in late summer flow in above-dam catchments represents only a few percent of annual yield, and much less than the storage capacity of the dams, but these long-term changes may be quite important for water yield during the late summer low-flow period. These findings are relevant for strategies to adaptively manage water resources in light of the ongoing planning for renegotiation of the U.S.-Canada Columbia River Treaty.Keywords: Columbia, trend, water, streamflow, rive
Semantic image segmentation using domain constraints
Get PDFThis dissertation addresses the problem of semantic labeling of image pixels. In the course of our work, we considered different types of semantic labels, including object classes (e.g., car, person), 3D depth values (in the range 0 to 80 meters), and affordance classes (e.g., walkable, sittable). Semantic pixel labeling is challenging as objects may appear in various poses, under partial occlusion, and against a cluttered background in the scene. To address these challenges in semantic segmentation, we developed approaches in a unified research theme that of incorporating domain knowledge in learning and inference. As our results show, domain knowledge helps to resolve various ambiguities in semantic segmentation. We addressed this problem in supervised and weakly supervised settings, where the former provides pixel-wise ground-truth annotations in training, and the latter provides ground truths only as image-level tags. Our approaches range from beam search based inference to deep convolutional neural networks (CNN). Our approaches achieved state-of-the-art performance on the benchmark datasets for all types of semantic segmentation problems.Our main contributions include:1. Efficient beam search based inference that guarantees to respect domain constraints.2. Novel deep neural architecture called neural regression forest, which integratesdecision forests with CNNs.3. Multi-scale CNN architecture for extracting and fusing diverse mid-level visualcues, including depth map, surface normals, and object localization.4. Constraint-based regularized learning of a CNN where constraints are defined asspatial relationships between objects in the domain.5. Weakly supervised learning of CNNs using neural attention cues.6. We introduced first manually annotated dataset for evaluating affordance segmentation.Keywords: computer vision, semantic image segmentation, deep learnin
A survey on continuous-time modulators : theory, designs and implementations
Get PDFRecently, delta-sigma modulation has become a widely applied technique for high-performance analog-to-digital conversion of narrow-band signals. Most of the early designs used discrete-time structure for good accuracy and good linearity. The transfer functions are independent of the clock frequency. However, high unity-gain bandwidths of the opamps are required to satisfy the settling accuracy required in the discrete-time designs. Continuous-time structure can potentially achieve higher clock frequency with less power consumption. the anti-aliasing filter can also be eliminated due to the anti-aliasing property of CT modulators. On the other hand, CT ADC have their own problems, such as jitter sensitivity and excess loop delay. In this thesis, the state-of-the-art of CT modulator is reviewed. The problems in the design of CT ADCs are analyzed and solutions to them are described. The theory, design and implementations of CT modulator will also be reviewed.Keywords: Continuous-Time, Delta-Sigm