Four aspects of factors influencing the accuracy of nondestructive chlorophyll (Chl) and nitrogen (N) measurement in fresh leaves were studied: (1) optimum wavelength (OW) identification; (2) indices development and evaluation; (3) influence of leaf properties; and (4) influence of meter parameters and sampling technique. Results were used to develop indices...
Landscape models for elk distribution developed at Starkey Experimental Forest and Range from 1993-1995 were tested on another landscape during 2003-2005 at Sled Springs Wildlife Demonstration Area. Using location data obtained from 23 wild elk captured and fitted with GPS telemetry collars, 8 spatial resource selection function models representing 8...
Stream temperature is a water quality parameter that directly influences
the quality of aquatic habitat, particularly for cold-water species such as Pacific
salmonids. Forest harvesting adjacent to a stream can increase the amount of
solar radiation the stream receives, which can elevate stream temperatures
and impair aquatic habitat. Oregon Forest...
Collegiate student's conceptual distinctions of what define a mathematical and a physical model seems to be affected by the epistemological beliefs they hold about this knowledge. These beliefs seem to influence student's thinking and reasoning as they embark on problem solving activities in collegiate mathematics. Student's epistemological beliefs of mathematical...
The encroachment of western juniper into mountain big sagebrush plant communities and the subsequent development of juniper stands results in significant changes in vegetation structure and complexity. This study described and compared vegetative structure and bird community measures among four cover types representing a broad range of structural stages among...
Cordia alliodora is used for reforestation programs and farm income in northern Costa Rica. This study investigated: 1) responses of C. alliodora associated with stand density, or trees/ha (TPH), and 2) plant diversity and biomass in the understory of C. alliodora plantations. Three Nelder plots, 31 temporary plots and 6...
Nine species of ectomycorrhizal fungi were grown in liquid media over a pH range of 2-7. Species fell into five major groups: (1)
growth significantly best only at the optimal pH, (2) growth increased with increase of pH, (3) significantly best growth spans three pH units, (4) spans four pH...
North American cultivation of Ribes L. may expand as small fruit growers seek species to diversify horticultural crops. The Ribes industry was suppressed for decades out of fear that cultivated black currants and gooseberries would intensify the fungal disease white pine blister rust (WPBR) on five-needle pine (Pinus L. section...
Oxidative stress that occurs during cryopreservation may be reduced by the addition of antioxidants. Vitamin E (Vit E), Vitamin C (Vit C), glutathione (GSH), lipoic acid (LA), glycine betaine (GB) and polyvinylpyrrolidone (PVP) were applied at four steps of the PVS2 vitrification protocol (pretreatment, loading, rinsing, and regrowth). Shoot tips...
As a preliminary step toward the establishment of a
70 mm. aerial photo timber inventory system capable of
generating accurate stand tables, stock tables, and gross
volume estimates, this project focuses on the development
of a system which (1) eliminates the need to measure tree
height on the photos through...
Large areas of non-coniferous communities in southwestern Oregon are thinned to reduce fire hazard and accomplish ecosystem restoration, under the assumption that current fuel loads are unnaturally high. Although Oregon white oak (Quercus garryana) woodlands are a characteristic landscape component in this region, little is known about their current or...
A feral pig population on Santa Catalina Island, California, was
studied for 17 months beginning in July 1980. Density was estimated
to be 21 to 34 pigs/km² (95% confidence interval) using capture-recapture
techniques. Dry season home ranges determined from
radio-telemetry data were small and differed significantly between
boars and sows....
Biological invasions pose one of the greatest threats to global biodiversity, but many naturalized invaders coexist with the native community. Community ecology theory provides a framework for understanding the mechanisms by which invaders might coexist with native species or exclude them from the community, thus informing management practices to maximize...
Rapid discoloration and checking of wooden surfaces when exposed outdoors has caused wood to fall out of favor as an outdoor building material, especially in applications where appearance is important. The surface appearance of wood products exposed outdoors can be improved through the application of film forming coatings or by...
The distribution of adult Pacific herring (Clupea harengue
pallasi) near Auke Bay, Lynn Canal, southeastern Alaska, varied by
depth and geographic area over 24 successive months during 1973-75.
From June through September, schools concentrated at 5- to 37-m
depths where zooplankton was abundant, and moderate currents were
present in a...
Reinforcement learning (RL) is the study of systems that learn from interaction with their environment. The current framework of Reinforcement Learning is based on receiving scalar rewards, which the agent aims to maximize. But in many real world situations, tradeoffs must be made among multiple objectives. This necessitates the use...
Farmers in the high plateau region of Algeria are
assumed to exhibit risk averse behavior, particularly, due
to highly variable weather conditions inducing income
instability over time. This in turn directly affects their
production behavior. The Eastern High Plateau (Setif) is
not a homogeneous region. In the El-Eulma daira, for...
The competition or rivalry for the use of water resources
among economic sectors of the Pacific Northwest and among geographical
regions of the western United States has intensified in recent
years. This rivalry and the long run prospects for water shortages
have increased the demand for research concerning the productivity...
The metabolic fate of cholesterol delivered to rat hepatocytes by rat plasma lipoproteins was determined. Binding and degradation of rat low and high density lipoproteins (LDL and HDL) in rat hepatocytes were studied. ¹²⁵I-labelled LDL and HDL were incubated with cells in the presence of varying concentrations of unlabelled lipoproteins...
In this thesis anomalous downcore shallowing of paleomagnetic
inclinations is interpreted to be caused by sediment compaction. Thus,
compaction-induced inclination shallowing may influence tectonic
reconstructions that are based on inclinations from deep-sea sediment
cores.
Progressive downcore shallowing of the remanent inclination was
observed in a 120-m section of Plio- Pleistocene...
DNA mismatch repair (MMR) plays an important role in preserving genomic stability and reducing cancer risk. Environmental exposures to polycyclic aromatic hydrocarbons (PAHs) are believed to contribute significantly to carcinogenesis. PAHs are found in food, air, water and soil and upon bioactivation can form diol epoxides which are electrophilic in...
Both transportation costs and market values of woody biomass are strongly linked to the amount of moisture in the woody biomass. Therefore, managing moisture in the woody biomass well can lead to significant advantages in the woody biomass energy business. In this study, two prediction models were developed to estimate...
Increased temperatures due to anthropogenic-induced climate change may raise the threat of extinction for taxa with sessile life histories (e.g., plants) in the near future. Linking climate change models to demographic models may provide useful insights into the potential effects of environmental changes on rare plants, and therefore aid in...
Mechanical behavior of Nb-Ti superconducting composites with copper matrices have
been studied experimentally and theoretically.
Experimental work includes extensive measurements of Cu/Nb-Ti composite system.
Techniques for fine fiber testing and composite wire measurement have been developed.
Experimental parameters examined in this research include geometry, hardness, Young's
modulus, Poisson's ratio, yield...
Stochastic analysis procedures have been recently applied to analyze nonlinear
dynamical systems. In this study, nonlinear responses, stochastic and/or chaotic, are
examined and interpreted from a probabilistic perspective. A multi-point-moored
ocean structural system under regular and irregular wave excitations is analytically
examined via a generalized stochastic Melnikov function and Markov...
The distribution and abundance of the interstitial acoel turbellarian,
Diatomovora amoena Kozloff, 1965 was studied in an
estuarine intertidal sand flat in Yaquina Bay, Oregon, from May
1970 through May 1971.
Monthly measurements of biological (organics, sulfides, chlorophyll,
and carotenoids), pore water (salinity, pH,oxygen, and temperature),
and sediment (fine sediment...
This study examines the effect of mood and fairness
of treatment on children's generosity toward peers.
Thirty-one third and nineteen fourth grade males participated.
A positive or negative mood was induced using
recorded stories. Each child then played a ring toss
game for which he had been promised a certain...
Seed yield in perennial ryegrass is the product of yield components
that develop during the life of the plant. Crop yield potential is
defined by the number of fertile tillers, spikelets per spike, and
florets per spikelet. It has been shown that perennial ryegrass
realizes only a small percentage of...
Populations of Western Tragopans Tragopan melanocephalus were studied at two areas (Machiara and Salkhala) in the Neelum Valley of northeastern Pakistan. A total of 130 sightings of birds was noted during the breeding seasons in 1982 and 1983, but only 100 were re-located for vegetation analysis. More sightings of birds...
Currently there is a great amount of interest in the phenomena of natural circulation as a cooling mechanism for normal operation as well as emergency conditions in nuclear reactors and spent fuel pools. In order to better understand this phenomena for the specific geometry of vertical, heated rods in water,...
Vibriosis caused by the bacterial pathogen Vibrio tubiashii is one of several factors contributing to mass larval mortalities of the Pacific oyster (Crassostrea gigas) in Pacific Northwest shellfish hatcheries in recent years. Genetically improved strains of the Pacific oyster resistant to V. tubiashii would be highly desirable. This study investigates...
A program of research has been established at Oregon State
University to study wood residue combustion using an experimental
spreader-stoker combustor. This research was conducted to increase
the understanding of combustion occurring in wood fired boilers.
Using Douglas Fir screened to 3/8-3/4 inches, two 4x4 factorial
experiments were conducted varying...
An experiment was conducted to examine the responses to
selection for high and low rate of gain in the mouse under a system
whereby inbreeding was maximized. Rate of gain was measured by an
index designed to include gains in both the pre- and postweaning
periods with the gains in...
A model of an exhaust plume was developed and programmed
on a digital computer. The purpose of the model was to predict the
concentration and size distribution of ice particles produced from
automobile exhaust during arctic conditions. The model accounted
for the nucleation, growth, and freezing of the condensed water...
The purpose of the study was to determine the current status
of provisions being made to provide for appropriate utilization of
the increasing quantities of audiovisual equipment and materials
available in the public schools of Oregon. The ultimate objective of
the study was to identify activities and programs essential to...
The Willamette River flows north between the Cascade Mountains and Coast Range of western Oregon within a 29,728-km² basin. The fish community in the geologically young basin consists of 36 native species, but introductions of non-native fishes have added 33 additional species for a total of 69 fish species. During...
Depletion-Based Stock Reduction Analysis (DB-SRA; Dick and MacCall, 2011) is a catch-only fisheries stock assessment model that has been developed to estimate an overfishing limit (OFL) in data-poor situations. DB-SRA projects the biomass trajectories of a stock by means of a catch time series and five parameters: the instantaneous, per...
Some of the most pressing conservation concerns involve declining populations of species with low fecundity and highly specialized foraging and reproductive requirements. Yet, we often lack a functional understanding of how individuals of those species interact with their environment, specifically how their movement is affected by human-induced changes. In order...
Recent climatic warming trends and increases in the frequency and extent of wildfires have prompted much concern regarding the potential for rapid change in the structure and function of forested ecosystems around the world. Episodes of mortality in wildfires and insect outbreaks associated with drought have affected large areas and...
The consumption of cruciferous vegetables is associated with several health benefits, including cancer prevention. Many of these benefits are attributed to the phytochemical, sulforaphane (SFN), which is derived from cruciferous vegetables such as broccoli and broccoli sprouts. These vegetables contain glucoraphanin (GFN), SFN’s precursor, which is converted to SFN by...
Empirical studies and theory have identified many early predictors of children's academic achievement and externalizing problems. Moreover, research shows that children's early cognitive abilities and behavioral problems are strong predictors of later academic achievement and externalizing problems. The current dissertation studies extend previous work and unpack how early predictors relate...
The family as a social unit is the earliest and most fundamental socialization influence and is an important contributor to children's development. Studies of family communication patterns (FCP) have emphasized two particular dimensions--a family's conversation orientation and their conformity orientation. However, many studies of FCP and its related outcomes have...
Currently, fungicide applications are the predominant method of control for the cool weather pathogen Microdochium patch (Microdochium nivale). Increasing pesticide restrictions have generated concern regarding management of Microdochium patch. Three separate field trials exploring non-traditional fungicides were conducted between 2013 and 2015 on an annual bluegrass (Poa annua L.) sand-based...
Self-regulation skills lay the foundation for short- and long-term school success, and strengthening these skills in early childhood can have significant implications for immediate and future life outcomes (e.g., Blair & Diamond, 2008; McClelland, Acock, Piccinin, Rhea, & Stallings, 2013). A large body of literature has investigated how characteristics of...
Early learning skills, such as executive function (EF), are a key component of healthy development and predict long-term academic success. Yet many children are entering kindergarten without the necessary skills (including EF) that are needed to set them on a successful learning trajectory. Early prekindergarten classrooms that encourage a high...