Interest in measuring soil quality continues to increase worldwide in view of demands on land productivity and the necessity to preserve soil resources, yet identification of suitable indicators for soil quality assessment is still evolving. This study adapted 10 biological, physical, and chemical indicators of soil quality identified by the...
We construct a website to explain how Gaussian mixture models can be optimized using the expectation maximization algorithm. Previous free, online material on this process has been extremely limited. All sources surveyed failed to entirely describe our identified criteria for an in-depth description and useful visualizations. After surveying a variety...
This thesis analyzes the emerging technology of hydraulic fracturing and shale gas extraction process through a pluralistic philosophical approach. Rather than defending traditional values in nature, such as intrinsic value, I defend a metaphilosophical pragmatism centered on policy implications. I argue that different philosophical positions will, most of the time,...
This thesis explores some of the ethical issues pertaining to the use of so-called radical enhancement technology. Key concepts analyzed include “normal function”, “human being”, and “personhood.” I argue that the use of these key concepts in the debate thus far has lacked philosophical rigor, and that a reexamination of...
Wastewater epidemiology is an emerging discipline that requires collaborative research involving analytical chemists, drug epidemiologists, and wastewater engineers. Wastewater epidemiology involves the sampling and quantitative analysis of raw wastewaters from communities for illicit drugs and their metabolites. Mass loads (mass per day) and per capita (mg per day per person)...
A sensitive, selective, rapid analytical method based on large-volume injection (LVI)
liquid chromatography/ tandem mass spectrometry was developed using
commercially-available hardware that eliminates the need for either off-line or on-line
solid phase extraction. Centrifugation followed by the direct injection of 1,800 µL
was used for the quantification of illicit drugs,...
The Arctic climate system is changing dramatically as a response to rising atmospheric greenhouse gas concentrations. Key indicators of Arctic change include thinning and retreating of Arctic pack ice, thawing permafrost, greening tundra, and rising surface temperatures. The structure of the atmospheric boundary layer influences and is influenced by processes...
The effects of wind forcing on coastal ocean circulation are studied using a
numerical modeling approach. The first region of interest is on the North Carolina
shelf, where the Coastal Ocean Processes (CoOP) Inner Shelf Study (ISS) took place
during August - November 1994. ISS observations are used to initialize,...
I defend robust realism from arguments that raise epistemological challenges to it based on considerations about either moral disagreement or the genealogy of our moral beliefs. The first argument is the “Argument from Conciliationism,” which contends that the moral disagreements that obtain between moral peers give us reason to believe...
Per- and polyfluoroalkyl substances (PFAS) are an emerging chemical class of concern. Recently in the United States, Health Advisory Limits for two PFAS in drinking water were established for perfluorooctane sulfonate and perfluorooctanoate in drinking water (set to 70 ng/L combine concentration) by the EPA. Because of PFAS mobility, persistence,...
The production of carbon and export to deep ocean sediments is linked to carbon partitioning between the ocean and atmosphere and is a key driver of climate change over the glacial-interglacial transition. Yet conflicting reconstructions create barriers to understanding changes to the carbon system over this important climate transition. Production...
Stable oxygen and stable carbon isotopes of foraminifera are widely applied in paleoceanographic reconstructions. Oxygen and carbon isotopes are typically measured using pooled sample analysis (i.e., the combination of several shells) or single-shell analysis (typically restricted to heavier shells that weigh above 10 µg). With pooled sample analysis, where many...
Marine heat waves are forecasted to increase in frequency and intensity under future climate scenarios, but little is known about the impact of these events on the one of the most commonly used proxies of ocean temperature - foraminiferal assemblages. This research explores the planktic foraminifera community along the Newport...
We present student perceptions of a new first-year engineering programming class that was designed by informed research practices. While the College of Engineering at Oregon State University saw a lot of major switching in the first year, there were not many students switching into computer science (CS). This could have...
This research was undertaken to develop a sensitive, selective, and rapid analytical method to measure ethyl glucuronide (EtG) and ethyl sulfate (EtS) in urine as urinary biomarkers of alcohol exposure. Large-volume injection (LVI) coupled with liquid chromatography / electrospray tandem mass spectrometry was used to eliminate the need for either...
To determine the impact of emerging environmental contaminants on human and environmental health, quantitative analytical methods are required. Analysis of emerging contaminants is hampered by their widely varying physical-chemical properties. Therefore quantitative analytical methods must be developed to determine the behavior of emerging contaminants in environmental systems.
A quantitative analytical...
Per- and polyfluoroalkyl substances (PFAS) are a group of anthropogenic compounds that are used ubiquitously in different industrial fields. However, concerns regarding the potential health impacts of PFAS, including perfluoroalkyl carboxylic acids
(PFCAs) and perfluoroalkyl sulfonates (PFSAs), has raised stakeholder interest regarding continued use of PFAS. Analytical methods for PFAS...
My dissertation title is, “Applied economic strategies to evaluate policies and environmental outcomes: case studies from immigration and ecosystem services.” The first two chapters of this dissertation concern the relationship between local immigration policies and societal welfare. The third chapter examines the impact of human activity on the environment and...
It is the responsibility of humans, as environmental stewards, to monitor our impact on the environment so that efforts can be made to remediate the effects of our actions and change behaviors. To better understand our environmental footprint, sensitive and simple analytical methods are needed to quantify the contaminants that...
In computer science, learning abstract fundamental programming concepts requiring students to understand memory management can be very difficult and lead to misunderstandings that carry on into advanced topics. This is especially true in data structures with abstract data types. Understanding how novice students think and reason about data structures is...
Beginning with the inception of American art history as a formal discipline in the 1940s, the dominant mode of interpreting nineteenth-century American landscape painting has been to view aspects of the landscape as symbols for grand cultural, religious, national, and moral narratives. While this method of interpretation highlights some key...
An Ls-isocitrate:NADP oxidoreductase has been isolated and
purified from embryonic chicken liver. The enzyme was purified
200 fold by means of ammonium sulfate fractionation, gel filtration
chromatography on Sephadex G-200, ion-exchange chromatography
on Bio-Gel CM-100 and adsorption chromatography on hydroxylapatite
gel.
The purified enzyme was nearly homogeneous as determined
from...
Salmon and other anadromous fish are consumed by vertebrates with distinct
life history strategies to capitalize on this ephemeral pulse of resource availability.
Depending on the timing of salmon arrival, this resource may be in surplus to
the needs of vertebrate consumers if, for instance, their populations are limited
by...
Full Text:
of the paper.
• Jennifer M. Allen performed the experiments, reviewed drafts of the paper
Salmon and other anadromous fish are consumed by vertebrates with distinct
life history strategies to capitalize on this ephemeral pulse of resource availability.
Depending on the timing of salmon arrival, this resource may be in surplus to
the needs of vertebrate consumers if, for instance, their populations are limited
by...
Salmon and other anadromous fish are consumed by vertebrates with distinct
life history strategies to capitalize on this ephemeral pulse of resource availability.
Depending on the timing of salmon arrival, this resource may be in surplus to
the needs of vertebrate consumers if, for instance, their populations are limited
by...
Salmon and other anadromous fish are consumed by vertebrates with distinct
life history strategies to capitalize on this ephemeral pulse of resource availability.
Depending on the timing of salmon arrival, this resource may be in surplus to
the needs of vertebrate consumers if, for instance, their populations are limited
by...
Salmon and other anadromous fish are consumed by vertebrates with distinct life history strategies to capitalize on this ephemeral pulse of resource availability. Depending on the timing of salmon arrival, this resource may be in surplus to the needs of vertebrate consumers if, for instance, their populations are limited by...
Crown gall disease is an agricultural problem caused by the soil-borne bacterium, Agrobacterium tumefaciens. A. tumefaciens oncogenes cause transformed plant cells to overproduce the hormones, auxin and cytokinin. High hormone levels cause unorganized plant cell growth resulting in a gall. Control of crown gall disease is difficult because after plant...
Science is difficult for even its researchers to understand. Science journalists must understand scientific discoveries well enough to write clear, accurate explanations of scientific discoveries for laypeople. A sense of ethical judgment will help journalists ensure that their accounts are reliable and appropriate. Responsible science journalists will maintain a working...
Full Text:
).
Arthur Allen, who covered thimerosal for the New York Times Magazine, wrote a response beginning with the
Museums, aquariums, and technology centers are informal learning environments that facilitate the understanding of scientific phenomena while supporting self-motivated learning. Families are a social group that frequently visits these sites. There are multiple opportunities for adults and children to engage in independent sense-making and collective discussion about their experiences with...
In arid and semi-arid deserts, soils are commonly covered with biological soil crusts. The
study of arid biocrusts and their ecological function has become increasingly common in
the literature over the last several decades. Interestingly, no mention is made of
biological soil crusts in forested ecosystems, raising the question as...
Greater sage-grouse (Centrocercus urophasianus), a sagebrush obligate species, has contracted in extent by nearly half its original distribution. This is primarily due to habitat loss and degradation over the past 150 years. During winter, sage-grouse depend completely on sagebrush habitat for food and cover, yet sage-grouse winter ecology has been...
In this qualitative, phenomenological study I employed
oral history methodology, grounded in a life-span
developmental and feminist approach, to explore the
developmental importance of menarche in twenty older women's
"bodily histories." Menarche is an important developmental
event in the female life course because it represents a major
point of confluence...
The War Production Board issued limitation order 85 in April 1942 in order to conserve fabric and manpower needed for the war effort. The L-85 order froze the silhouette so no major style changes in women's wear would occur during the war. It is clear that on the one hand...
Pacific salmon are an integral part of ecosystems, industry, culture, and food source. Rapid declines and extirpation in many populations and species have caught the interest of environmentalists, scientists, recreational anglers, commercial fishers, general public, and economists. Billions of dollars have been spent to restore, return, improve, sustain dwindling populations...
An experiment was conducted to determine the effect of dietary copper (Cu)
on Cu status and lipid metabolism in Holstein and Jersey cattle. Eight Jersey and8
Holstein cows in mid-lactation were blocked by days in milk (169 ± 37) and
assigned at random to one of two diets. Cows received...
Internal waves and tides are a dominant source of current variability, and they are intermittent and hard to predict. Internal waves can have significant variability in alongshore structure. However, previous studies on internal waves have focused primarily on their cross-shore structure and propagation. For example, while alongshore-propagating superinertial internal tides...
Large burrowing owl (Aihene cunicularia) populations exist in areas of intensive agriculture in California, and pesticide exposure has been identified as a potential threat to population persistence. I evaluated breeding season use of agricultural fields by adult male owls using radio telemetry, and examined egg contaminant residues to estimate population-level...
This research summarizes the cumulative efforts of in-depth research,
extensive participant observation, and archival analysis focused on Southern Oregon
lesbian lands. This community of womyn has persisted in rural Southern Oregon for
nearly 30 years. The intention of this study is to examine both the accumulation of
knowledge of issues...
Trichloroethene (TCE) is a common groundwater contaminant. Bioremediation, or the enhancement of natural microbial processes for the transformation of toxic compounds in soil and groundwater, is an effective solution to this widespread problem. The organisms that transform TCE in the subsurface are sensitive to environmental conditions, especially to the presence...
Behavioral studies of populations provide clues as to what influences their
movements and life history strategies. This is an area of study that has been
underutilized in research surrounding the declining western stock of Steller sea
lions, Eumet opias jubatus, particularly with regards to haulout behaviors. During
the time of...
Clean cooking technologies and fuels have been cited as a viable way to slow climate change and reduce the health and environmental impacts associated with traditional cooking devices used by 40% of the world. While engineers in the Design for Development sector have created hundreds of stove designs that perform...
The US bridal industry has grown over the last 80 years to become a multibillion
dollar industry. Surprisingly, little research has been conducted concerning
the consumer behavior of brides. The bride is in a situation where purchase
decisions need to be made. She has many things she will purchase over...
Self-regulation in early childhood encompasses higher-order executive function processes and lower-order emotional responses that enable children to navigate the classroom environment. Although self-regulation and executive functions are overlapping constructs, self-regulation represents a broad assessment of children’s ability to call upon executive function processes in order to meet contextual demands. Prior...
Forest harvest can have significant impacts on forest ecosystems that may influence the capacity of soils to sequester carbon (C). The microbial community controls decomposition, which is a critical process in partitioning litter- and root-C between CO₂ and storage in semi-permanent soil-C pools. The objectives of this study were to...