Radiative feedbacks associated with changes in water vapor, temperature, surface albedo and clouds remain a major source of uncertainty in our understanding of climate's response to anthropogenic forcing. In this dissertation climate model data is used to investigate variations in feedbacks that result from changing CO₂ forcing and the time...
Are equilibrium climate sensitivity and the associated radiative feedbacks a constant property of the climate system, or do they change with forcing magnitude and base climate? Using the radiative kernel technique, feedbacks and climate sensitivity are evaluated in a fully coupled general circulation model (GCM) for three successive doublings of...
Climate feedbacks vary strongly among climate models and continue to represent a major source of uncertainty in estimates of the response of climate to anthropogenic forcings. One method to evaluate feedbacks in global climate models is the radiative kernel technique, which is well suited for model intercomparison studies because of...
Root rot of sweet corn in western Oregon and Washington is a significant disease that
can reduce yield of intolerant cultivars of processed sweet corn by fifty percent. Root rot
is caused by a complex of soilborne organisms, including Drechslera sp., Phoma
terrestris, and Pythium arrhenomanes. Processors have adopted tolerant...
:
_______________________________________________________________________
Alexandra G. Stone
Root rot of sweet corn in western Oregon and Washington is a
Winter squash is an important late winter vegetable crop for local and regional markets; however, farmers in western Oregon report that this crop is marginally profitable due to losses in storage and relatively low yields for the high culinary value kabocha and buttercup types. In order to increase the sales...
Annual applications of fresh or composted dairy manure were assessed for their effects on root rots of sweet corn and snap bean and damping-off of cucumber in a field soil. Soil biological and physical properties were measured as possible indicators of root rot suppressive potential. Regardless of amendment type or...
The effect of serial (multiple-year) organic matter (OM) amendment on soil properties has been described in some cropping systems, although less is known about the effect of serially amended field soils on soil-borne plant diseases. The objectives of this study were to describe the effects of the third and fourth...
The increase in atmospheric concentrations of water vapor with global warming is a large positive feedback in the climate system. Thus, even relatively small errors in its magnitude can lead to large uncertainties in predicting climate response to anthropogenic forcing. This study incorporates observed variability of water vapor over 2002–2009...
As part of a participatory research project, where farmers and Oregon State University researchers collaborated, aspects of potato (Solanum tuberosum L.) growing systems were studied. It was determined through conversations with the farmers that quantification of certain growth parameters of potato was lacking, including dry matter accumulation, crop nitrogen (N)...
This thesis follows two studies performed with simple robots. The first follows a robot interacting with eight improvisers to create scenes and perform five isolated gestures (towards, away, sideways, spin, and circle) for interpretation. The second follows a group of three robots performing the same five isolated gestures at two...
Rhizopogon salebrosus is an abundant ectomycorrhizal fungus common throughout Western North America that forms mutualistic partnerships with Pinus species. Studied for its systematics, use in sapling nurseries, post-fire seedling establishment, and unique evolutionary history, R. salebrosus holds many secrets within its genome. This thesis aims to characterize the mating system,...
_____________________________________________________________________
Alexandra Weisberg, Committee Member, representing Department of Botany and Plant
Pathology
This thesis details investigations of marine cyanobacterial secondary metabolism, with emphasis on a strain of Phormidium sp. collected in Indonesia. These studies assessed the effects of nineteen putative elicitor compounds on the growth and metabolite production of five species of marine cyanobacteria, biosynthetic investigation of an intriguing secondary metabolite, phormidolide,...
We used both culture-dependent and culture-independent approaches to purify genomic DNA, and PCR to amplify 16S rRNA genes from soil sample microbes. We then sequenced the 16S rRNA amplicons of the bacterial species as well as the genomic DNA of one chosen cultured organism to identify and describe the soil...
Connectivity of fish populations is a crucial question for fisheries conservation and the development of spatial management plans. Both adult and larval movement define the extent and direction of ecological and evolutionary overlap between geographic regions and, therefore, how we define stocks for management purposes. Within that context, my work...
Domesticated cats frequently use their sense of smell to navigate their environment, convey social cues, and communicate with other individuals. In applied contexts, cat owners are often encouraged to leave items holding their scent with their cat in periods of absence with the aim of reducing stress. The purpose of...
The objectives of this study were to: 1) determine how organic matter (incorporated vs. surface mulch) and nitrogen fertilization rate impact northern highbush blueberry (Vaccinium corymbosum L.) plant biomass, carbon accumulation, plant losses and allocation, and mycorrhizal infection in mature plants, and 2) determine the magnitude of carbon fluxes (carbon...
This research examined public perceptions of risk, behavioral intentions in the event of the M9 Cascadia Subduction Zone (CSZ) earthquake and tsunami on the Oregon Coast, and factors that may influence both attitudes and intentions. A household survey was conducted to understand public opinion in Seaside, Oregon, which is located...
A wave-by-wave forecasting system is desired for optimization of wave energy conversion devices and for improving safety of vessel-based marine operations. This study outlines the first validation attempts of a recently developed forecasting system called Wavecast. The forecasting approach uses X-Band marine radar images for data assimilation, then reconstructs and...
Previous research on WWII veterans in their 70’s and 80’s has shown that positive and negative appraisals of military service mediate between combat exposure and PTSD symptoms in late life. This thesis extends this research in two ways, first by determining how these variables relate to functional health in later...
Watermelon (Citrullus lanatus) is rich in lycopene and citrulline and has high phenolic content and antioxidant capacity. Previous studies demonstrate the health benefits of watermelon intake on improved blood pressure regulation along with others. Similarly, cherries, raspberries, walnuts and green tea are rich in anthocyanins, polyphenols, and polyunsaturated fatty acids...