The main objective of this thesis was to determine the influence of tree vigor on susceptibility to Armillaria root disease. First, the effect of thinning, fertilizing
and pruning on tree vigor of four young Douglas-fir (Pseudo tsuga menziesii var.
menziesi,) plantations was explored. Tree vigor was calculated by measuring wood...
The main focus of this work is on the problem of existence of nonlinear optimal controllers
realizable by artificial neural networks. Theoretical justification, currently
available for control applications of neural networks, is rather limited. For example,
it is unclear which neural architectures are capable of performing which control
This research was conducted as part of the Strategic Highway Research Program (SHRP)
A-003A contract at Oregon State University to validate the findings of SHRP contracts
A-002A and A-003B with regard to aging of asphalt-aggregate mixtures. One short-term
and four long-term aging methods were used to simulate aging of asphalt-aggregate...
Nisin is an antibacterial peptide, which when adsorbed
on a surface can inhibit bacterial adhesion and viability.
The ability of noncovalently immobilized nisin to withstand
exchange by the milk proteins bovine serum albumin, β-lactoglobulin, α-lactalbumin, and β-casein on surfaces that
had been silanized with dichlorodiethylsilane to exhibit
high and low...
Diode lasers have many advantages such as small size, high efficiency and small
angular dispersion of the collimated beam. However they also have some problems like
lack of frequency stability. They can not be tuned in wavelength. An external cavity can
solve these problems and decrease the laser linewidth.
The objectives of this research were to 1) evaluate the establishment and peak
standing crop of Berber Orchardgrass (Dactylis glomerata var. "Berber"), Palestine
Orchardgrass (Dactylis glomerata var. "Palestine"), and Sheep Fescue (Festuca ovina
var. "Covar") ; 2) to assess establishment and production changes resulting from
environmental gradients (elevation, slope, aspect,...
The wind speed and significant wave height (H1/3) dependencies of the sea state is in altimeter estimates of sea level, expressed in the form ∆hSSB=bH1/3, are examined from least squares analysis of 21 cycles of collinear TOPEX data. The bias coefficient b is found to increase in magnitude with increasing...
Alias periods and wavelengths for the M2, S2, N2, K1, O1, and P1 tidal constituents are calculated for TOPEX/POSEIDON. Alias wavelengths calculated in previous studies are shown to be in error, and a correct method is presented. With the exception of the K1 constituent, all of these tidal aliases for...
Altimetric data from the TOPEX/POSEIDON mission will be used for studies of global ocean circulation and marine geophysics. However, it is first necessary to remove the ocean tides, which are aliased in the raw data. The tides are constrained by two distinct types of information: the hydrodynamic equations which the...
In 1987, Congress authorized a 5 year $150 million dollar research program called
the Strategic Highway Research Program (SHRP). SHRP was divided into four major
areas, including the asphalt research program. The asphalt research program was divided
into six major research contracts, one such contract, SHRP-003A was called Performance
A new method for encapsulating low-molecular weight, water-soluble substances
in lipid-walled microcapsules (LWMs) for delivery to marine bivalves was developed,
characterized, and tested. LWMs produced by a spray technique (spray microcapsules,
SMs) were demonstrated to encapsulate both aqueous (polymeric dye or oxytetracycline
hydrochloride) and particulate (riboflavin) core materials within a...
The incipient motion of sediment particles in gravel-bed
rivers is a very important process. It represents the
difference between bed stability and bed mobility. A field
study was conducted in Oak Creek, Oregon to investigate
incipient motion of individual particles in gravel-bed
streams. Investigation was also made of the incipient...
Forest recreation is one of the many non-commodity functions of forests that have
experienced a rapid growth in demand in the past few decades. Even faster growth in
demand for recreation is expected for several decades. However, such growing demand
for forest recreation is often not well perceived by owners...
The island of Tahiti, the largest in French Polynesia, comprises two major volcanoes aligned NW-SE, parallel with the general trend of the Society Islands hotspot track. Rocks form this volcanic system are basalts transitional to tholeiites, alkali basalts, basanites, picrites, and evolved lavas. Through K-Ar radiometric dating we have established...
There is renewed interest in agroforestry as a management strategy for marginal agricultural lands in western Oregon. Silvopastoral systems combine tree and
forage production, which involve crops and practices familiar to the area. The objective of this study was to determine how
management influences the physiology and ecological interactions of...
Lichen sensitivity to air quality has been recognized in Europe
for over 125 years: recently Federal agencies in this country have
begun using lichens as air quality bioindicators. This study presents
the results of three different approaches to air quality biomonitoring
using lichens: (1) a lichen community analysis, (2) an...
This thesis presents the design of various controllers for a highly maneuverable, high performance aircraft, namely the modified F-18. The aircraft was required to perform high angle-of-attack maneuvers, for which the aircraft behaves in as a highly nonlinear system. An adaptive PID controller was used to control the aircraft through...
This study explored perceptions of performance feedback communicated by
Japanese supervisors to their U.S. subordinates in Japanese subsidiaries in the U. S.
Individual face-to-face interviews were conducted with both Japanese supervisors and
U.S. subordinates and their responses were tape-recorded. The purpose of the study
was to assess perceptual similarities and...
This study investigated the job satisfaction of
elementary school counselors in the Pacific Northwest,
defined as Idaho, Oregon, and Washington. The purpose of
the study was to (a) describe current elementary counselor
characteristics, duties and functions; (b) determine the
overall level of job satisfaction of elementary school
counselors; (c) investigate...
The gonadal steroids, testosterone and estradiol, are known to be important
modulators of neuronal functions and behaviors in most vertebrate species. These
steroid hormones also elicit changes in neuropeptide synthesis and secretion, alter
specific neurohormone receptor levels, and alter neuronal morphology and
electrophysiology. Many of the actions of androgens and...
I have participated in a drug discovery program designed to screen marine algae for
inhibitors of cancer-related enzymes, antitumor compounds, antiinflammatory substances,
and other agents of potential pharmaceutical utility. Over 1,500 lipid and aqueous extracts
of marine plants and animals were surveyed for biomedical potential. Assays designed to
This thesis asserts that faculty are the critical resource for the integration of distance
education by postsecondary institutions. The major barriers to the participation and
adoption of distance education center around faculty. This manuscript thesis incorporates a
series of articles to develop applied frameworks and strategies that place faculty at...
Groundwater contamination on irrigated land is of concern in this nation
and around the world. In order to reduce the potential of groundwater
contamination by agricultural practices such as irrigation, fertilizer and pesticide
application, vadose-zone monitoring and sampling are needed. The main
objective of this study was to evaluate impacts...
Maize defective kernel (dek) mutants identify genes necessary for the
successful passage of embryos through the embryogenic and maturation
phases of embryo development. The goal of this thesis was to characterize the
developmental potential of three dek mutants that appeared to be
morphologically blocked prior to the maturation phase of...
Multiparadigm languages are languages that are designed to support more than one style of programming. Leda is a strongly-typed multiparadigm programming language that supports imperative, functional, object-oriented, and logic programming. The constraint programming paradigm is a declarative style of programming where the programmer is able to state relationships among some...
We introduce a relativistic model for pion-nucleon scattering which includes an elementary
delta dressed by its decay. Crossing-symmetric single-particle exchange
is augmented by parametrized multiple-scattering interactions, with covariant sideways
form factors in both 3- and 4-field vertices. Causality is enforced by dispersion
relations. Unitary fits to observed on-shell amplitudes are...
The effects of harvesting Pacific hake (Merluccius productus)
were examined with a multi-species numerical model composed of
seven logistic growth equations coupled by a food web. The
food web was composed of: California sea lions (Zalophus
californianus), hake, sablefish (Anaplopoma fimbria), spiny
dogfish (Squalus acanthias), a generic rockfish species
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 mammalian FMO represents a multigene family which
oxygenates a large number of xenobiotics. No physiological role has
been determined for FMO, although synthesis of disulfide bonds and
detoxification of dietary chemicals have been suggested. Five FMO
gene subfamilies, each containing a single gene, have been identified.
In this study,...
Sampling error associated with estimates of species composition and age composition
of commercial groundfish landings in Oregon from 1989 to 1991 is documented to evaluate
the impact of variable landing data on fisheries management and monitoring programs. The
statistical reliability and bias associated with two multistage sampling designs are
Although soil tillage has been used successfully to alleviate compaction of forest soil after logging in a number of management contexts, little is known about the feasibility of tilling in residual stands. In an attempt to weigh the benefits of tillage against possible damage done to residual trees during tillage,...
The studies presented here use the B- to Z-DNA transition and Z-DNA
crystallization as model systems to determine the contribution of solvent interactions to
macromolecular structures. The substituent groups of naturally occurring and modified
nucleotide bases affect the hydration and thus the stability of right-handed B-DNA and
left-handed Z-DNA. The...
Carbon isotopically based estimates of CO₂ levels have been generated from a record of the photosynthetic fractionation of ¹³C (≡εp) in a central equatorial Pacific sediment core that spans the last ~255 ka. Contents of ¹³C in phytoplanktonic biomass were determined by analysis of C37 alkadienones. These compounds are exclusive...
Data from the Hydrological and Atmospheric Pilot Experiment-Modélisation du Bilan Hydrigue (HAPEX-MOBILHY) field program and results from a one-dimensional model of the soil and atmospheric boundary layer are analyzed to study the daytime evolution of the relative humidity at the boundary layer top. This evolution is thought to control the...
Alcoholic off-flavor and accompanying volatile compounds produced by
bananas (Cavendishii spp) held at 20°C and subjected to aerobic (air control
treatment) or anaerobic conditions (nitrogen treatment) were compared by solid
phase micro extraction (SPME), a newly developed method for volatile
separation. In general, volatile production was suppressed under anaerobic
Oregon's rocky intertidal habitats have been subjected to gradually increasing human-use pressures as the coastal and tourist populations have risen over the years. Brosnan and Crumrine (1991,1992) have documented impacts to intertidal communities at Yaquina Head, Sunset Bay, and Haystack Rock that have resulted from people walking on the intertidal...