Few studies have directly compared denitrifying community composition and activities in soils by coupling molecular-genetic techniques and traditional measures of denitnfication. I investigated communities of denitrifying bacteria from adjacent meadow and forest soils in the Cascade Mountains, Oregon. A key gene in the denitrification pathway, N₂O reductase (nosZ), served as...
Seeding is a vital tool to facilitate recovery of degraded ecosystems, but low seedling recruitment rates limit the utility of this practice in a range of ecosystems across the globe. Plant functional traits impact individual fitness through effects on growth, reproduction and survival. Consequently, seed and seedling trait variation among...
Measurements on growth traits up to 41 years of age
from 68 progeny sites in eight first-generation breeding
zones of coastal Douglas-fir (Pseudotsuga menziesii
[MIRB.] FRANCO var. menziesii) in the US Pacific Northwest
were used to investigate age trends of genetic parameters
and to determine optimum age of selection. Heritabilities...
Queer students in American public schools may face significant challenges including unsupportive or hostile peers or staff members (Eisenberg et al., 2017). The culture of rural Southern schools may be particularly challenging for these students as they are less likely to have an active support group and more likely to...
Oregon Fishermen in Ocean Observing Research (OrFIOOR) is a cooperative research program between ocean scientists and fishermen in the Pacific Northwest. Dungeness crab fishermen attach sensor packages (temperature and dissolved oxygen) to crab pots. The pots serve as platforms of opportunity for ocean observing. This study examines three principle questions...
Predicting the average affect of a piece of music is a task which has been of recent interest in the field of music information retrieval. We investigate the use of sentiment analysis on online social media conversations to predict a song’s valence and arousal. Using four music emotion datasets -...
Successful ecosystem restoration requires an understanding of the ecological processes directing succession. One of the challenges in the semi-arid grasslands of western United States is replacement of native species by invasive annual grasses. Solutions to this problem require identifying and manipulating ecological processes that direct succession to favor desired vegetation....
The extent in which the evangelical Christian perspective influenced the career decision-making self-efficacy of six female college students was qualitatively explored. Interviews and a focus group were utilized to find common themes and influences amongst the women. Literature from the areas of female college student development, career decision-making self-efficacy, and...
This is a phenomenological research study of the lived experience of women student mentors at one community college located in an urban setting on the West Coast. The study participants were women students who served as mentors to other women at the community college who are participants in a returning...
The study of the infra-specific ranks (i.e., subspecies and variety) can be considered
the study of the process of speciation. Astragalus lentiginosus Douglas ex Hooker
(Fabaceae) is the most taxon rich species in the U.S. flora currently including 40
taxonomic varieties. These varieties were described using traditional taxonomic
methods primarily...
A sequence of volcanic, volcaniclastic, and epiclastic deposits from Oligocene to Recent age are exposed in the region from Lake
Simtustus to Madras in central Oregon. The epiclastic sediments of the Oligocene John Day Formation are unconformably overlain by two flows of the middle Miocene Columbia River Basalt Group. The...
Full Text:
AN, ABSTRACT OF THE THESIS OF
Jeremy B. Jay for the
Solid state luminescent sulfides are prepared as powders in order to elucidate the relationship between structure and light emission. While the sulfides studied in this dissertation are known phosphors, materials are investigated in a variety of new ways. Elementary properties and structures of MgS are reviewed, and preparation of MgS...
This dissertation explores one overarching question relevant to the
paleoclimate of the latest Pleistocene glacial cycle (approximately the last
130,000 years): “How did spatial and temporal evolution of ocean
temperature, both at the surface and interior, relate to other parts of the
climate system in the late Pleistocene?” Results from...
High early strength concrete (HESC) allows for faster construction with less impact on traffic, thus reducing the indirect costs associated with a project. There are multiple methods for achieving early strength, such as alternative cements like calcium sulfoaluminate (CSA) or chemically accelerated portland cements. The standard criteria for an HESC...
Ocean Acidification (OA) has emerged as a major threat to marine ecosystems, particularly regarding calcifying organisms. A growing body of literature describing laboratory investigations into pH stress indicates broadly deleterious effects for calcifiers, but responses vary greatly across taxa and can be influenced by variations in other environmental characteristics. Scaling...
Pure glycerol and the crude waste glycerin byproduct of biodiesel production were tested as substrates for electricity production in single-chamber, air-cathode microbial fuel cells (MFCs) and in single-chamber microbial electrolysis cells (MECs), using pure and mixed microbial cultures as anode biocatalyst. Current densities of 0.40 A/m² and 0.13 A/m² were...
Reinforcement learning has emerged as a popular tool for solving control tasks, with multiple works focusing on the complex and dynamic task of locomotion. However, the naive application of reinforcement learning to this problem often produces maladaptive policies that exploit the model or reward function. This results in behavior that...
Wind and solar energy levels are expected to increase in the Pacific Northwest as a result of maturing renewable energy technologies, and state and federal policies. Because wind and solar energy is intermittent, only producing electricity when weather conditions permit, the integration of these resources has posed challenges to operators...
Due to public and regulatory restrictions, genetic containment technology is critical for research and development of transgenic trees in forestry. A multi-year field trial demonstrated that the RNAi-LFY construct successfully induces sexual sterility in 6K10 poplar (Populus alba) without visible effects on vegetative development. However, its limited number of replicates...
Elevated groundwater nitrate (NO3
-) concentrations in the Southern Willamette
Valley (SWV) caused the Oregon Department of Environmental Quality (ODEQ) to
declare a Groundwater Management Area (GWMA) in Spring, 2004. To better
understand direction of groundwater flow, groundwater age, and nitrate transport
pathways of the SWV we developed a steady-state...
Marine environments provide services for ecosystems and humans, but face many threats, including sea star wasting disease (SSWD) and ocean acidification (OA). Biological research on these threats is abundant, but there has been limited research examining the human dimensions of these threats. This thesis contains two standalone articles that explore...
A Diels-Alder approach to biaryls (DAB) has been applied towards the synthesis
of highly substituted, programmable biaryl templates. Tri- and tetra-ortho-substituted
biaryls can be produced in just three to four steps from commercially available materials
utilizing the Diels-Alder [4+2] cycloaddition. The methods described herein will
illustrate the ability of mono...
Mandelalide A has attracted considerable interest from the synthetic community due to its intriguing structure and important cytotoxic activity. Madeirolide A, a structurally related macrolide, shows promising antifungal activity but no appreciable anticancer activity. This dissertation describes synthetic studies toward mandelalide A, madeirolide A and their hybrid structures.
Part I...
Part I of this dissertation includes the chronological synthetic background of mandelalide A as well as the synthesis of the C1-C14 glycosylated southern subunit of mandelalide. A key aspect of the synthesis includes a novel silver-catalyzed cyclization (AgCC) of a propargylic benzoate to construct the substituted cis-pyran ring system present...
This dissertation is separated into two parts according to the two major distinct research projects. In Part I, the full account of synthetic studies toward C10-functionalized lycopodium alkaloids is described. In Part II, the detailed discussion on the exploration of the Pummerer cyclization methodology and its application to the total...
The structural architecture present in marine toxin azaspiracid - 20 stereocenters, 9 rings, 3 separated spirocenters - has attracted considerable synthetic attention. Our efforts toward the synthesis of azaspiracid have led to the completion of both C₁-C₂₆ northern and C₂₇-C₄₀ southern halves. Herein, the
synthesis of southern FGHI ring system...
More than 30 members of the diverse amphidinolide family of biologically active macrolides have been isolated over last three decades. From this family, amphidinolides C and F stand among the most complex and densely functionalized affiliates. Recently, we have accomplished the first total synthesis of amphidinolide F. The all-carbon framework...
An expedient approach to the synthesis of a wide range of highly programmable biaryl templates has been accomplished. Utilizing the Diels-Alder [4+2] cycloaddition, a wide range of tri- and tetra-ortho-substituted biaryls have been synthesized in only three to four steps from commercially available materials. We have successfully synthesized entire classes...
This thesis is separated into three distinct projects. First, synthetic studies towards the furanosteroid viridin shown in part I. Second, synthetic studies towards the diperene obtusanal shown in part II. Third, the analysis, characterization, and synthesis of coronene derivatives towards their application in organic batteries shown in part III. Significant...
The enantioselective total synthesis of quinolizidine-containing natural product cermizine D and formal syntheses of senepodine G and cermizine C has been achieved. These natural products are members of the lycopodium alkaloids, which have attracted significant attention due to their exciting biological activities and the diverse structural scaffolds. Key steps in...
Lycopodium alkaloids have shown widespread and noteworthy biological activity, consisting of over 250 known natural products. Moreover, their structural complexity and diversity have attracted considerable attention from numerous laboratories including our own. Recently, we have developed a unified approach that would provides access to numerous, previously unprepared C₁₀-functionalized lycopodium alkaloids....
The furanyl diterpenoid family of natural products has drawn the attention of both synthetic organic chemists and pharmacologists due to their complex structural architectures and diverse biological activity. Among them, wortmannin has been most extensively studied for biological activities. All these furanyl diterpenoids consist of a highly strained naptha[1,8-bc]furan core,...
Lycopodium alkaloids have generated enormous amounts of interest from the scientific community, both as synthetic targets and for their medicinal properties. Herein is described work towards a unifying approach to large segments of the Lycopodium family. An organocatalyzed intramolecular heteroatom Michael reaction method, for the construction of piperidine and piperizine...
The work described herein details the synthesis and application of
biphenyls that probe the effects of hydrogen, Cl / Br, and methyl substituents
on the aryl ring of the terminal acetylenic carbon. From this work, we
successfully developed the rapid synthesis of phenyl acetylenes in 3-4 steps
from inexpensive commercially...
Azaspiracid has generated an enormous amount of scientific interest in the fourteen years since its initial discovery. The structure contains a 6,5,6 bis-spiroketal, a [3.3.1] bicyclic ketal and a 6,5-spiroaminal linkage as key moieties. With 9 rings, 20 stereocenters and three alkenes, the azaspiracid immediately attracted the interest of the...
Effective methods for the enantiopure formation of substituted piperidine rings are significantly important due to their presence in alkaloid products. A valuable method to form these ring systems would be via an intramolecular heteroatom Michael addition from the corresponding enone or enal. Described herein is a methodolgy that has been...
Part 1: A Diels-Alder Approach to the Synthesis of Novel Analogues of the Natural
Product Siamenol
Due to the prevalence of biaryl motifs in natural product synthesis, the Carter
research group has been exploring the utility of a Diels-Alder approach to biaryl
synthesis. The Diels-Alder approach involves a [4+2] cycloaddition...
To effectively study dynamic processes like forest succession over long time periods one must effectively integrate data collected at many different times, locations and spatial scales. The purpose of this research is to integrate forest inventory data collected by the USDA Forest Service’s Forest Inventory and Analysis (FIA) Program with...
A primary objective of fishery management is profit maximization, accomplished by managing externalities associated with catching fish, while acknowledging that some margins of fishing fall beyond regulatory bounds. Regulation often does not address the larger economy of which the fishery is a part, focusing instead on the cost--benefit structure of...
The value per-acre and annual amortization of
rural land varies dynamically by parcel size. There are
several adjustment factors or independent variables
spatial, productive and development potential which affect
the market value of all rural land. The evaluation of
these must be accomplished by parcel size to be realistically
equated....
Animation has long been a staple of children's television programming As
public service announcements (PSA5) have become an important part of children's
television programming, cartoon characters have started to appear in this form of
nonprogram material. By standard definition, PSAs are usually a 15 to 60-second spot
that promote education...
Bioremediation of chlorinated ethenes by the augmentation of contaminated soils with microorganisms is a proposed method of reducing contaminant concentrations in groundwater. To determine the viability of using ELW-1 or R. rhodochrous for groundwater remediation, kinetic analyses of transformation rates must be performed. The focus of this research was to...
Biological plant invasions are diminishing the ecological integrity and function of ecosystems worldwide. A primary example of this is in the Great Basin of the United States, where invasive annual grasses, like cheatgrass (Bromus tectorum L.) and medusahead (Taeniatherum caput-medusae L. Nevski), are dominating many sagebrush-steppe ecosystems. In these invaded...
The semiconductor gallium arsenide (GaAs) has many potential
advantages over the more widely used semiconductor silicon (Si).
These include higher low field mobility, semi-insulating substrates,
a direct band-gap, and greater radiation hardness. All these
advantages offer distinct opportunities for implementation of new
circuit functions or extension of the operating conditions...
Landslides are an insidious natural hazard, which can result in significant damage to public infrastructure. Limited monitoring tools are available, particularly tools suitable for use in forested environments. These tools often only allow a few locations across the slide to be monitored. Terrestrial Laser Scanning (TLS) shows promise as a...
Fusion reactions with radioactive neutron-rich projectiles have been the subject of much recent theoretical and experimental interest. Predictions of enhancement of the cross section due to the use of a neutron-rich projectile may have implications for synthesis of heavy nuclei. In this work, the fusion-fission excitation functions were measured for...
While exercise can be prescribed for improving cardiovascular and muscle health, no prescription exists for increasing bone mass. Because bone deformation rate has been identified as an important variable related to osteogenesis, estimates of skeletal loading during human activities likely characterize the associated osteogenic stimulus. However, estimates of body segment...
This research investigates the electronic properties of a fungi-derived pigment, xylindein
as a novel sustainable material for organic electronics. Xylindein molecules were characterized in solution and in film. Absorption spectra and (photo)luminescence spectra were
taken at various excitation wavelengths. Xylindein’s molecular properties were computed
with the Gaussian 09 software suite....