We identify all translation covers among triangular billiards surfaces. Our main tools are the J-invariant of Kenyon and Smillie and a property of triangular billiards surfaces, which we call fingerprint type, that is invariant under balanced translation covers.
This dissertation addresses two main issues involving alcohol markets. In the first, we employ both parametric and nonparametric methods to analyze the market structure and estimate the degree of market power in the U.S. brewing industry. In the nonparametric case, we use the variations in the excise tax to test...
This thesis presents methods to reduce the effects of finite opamp DC gain, output voltage swing limitations in opamps, and component mismatches. The primary contribution of this thesis is a new switched-capacitor method named correlated level shifting (CLS). CLS enables true rail-to-rail operation by storing an estimate of the desired...
Wave breaking in the surf zone is an important forcing
mechanism on the generation of nearshore currents and in the driving
of sediment transport. At the same time, wave breaking can have
significant spatial and temporal variability that needs to be
accounted for in the description of nearshore processes. Remote...
As recreation and tourism visitation increases and government budgets decrease, public
land management agencies are using private commercial operators as an alternative
source of offering products and services. Changes and trends in commercial outdoor
recreation and tourism such as a large scale increase in the number of visitors can affect...
The seasonal duration of snow cover is a primary factor influencing the patterns of vegetation in high subalpine and alpine environments, but little is known concerning the responses of plant reproduction and
seedling recruitment to gradients of snow-release. Vegetation patterns of a high subalpine site in the Oregon High Cascades...
This is a study of the ecology of the timberline and alpine vegetation of the Three Sisters which are located in the
central Oregon Cascades. The Sisters are a close group of three 1O,000-foot volcanic peaks. Volcanic activity within the last few hundred years as well as recent glaciation have...
Although some of the most difficult problems in forest management occur as a result of timber harvest operations, present methodology in harvest planning emphasizes guidelines which rely heavily upon the experience of the individual forest manager for their correct application. This study was undertaken in an effort to develop a...
The vegetation following forest site preparation was examined in ten clearcut units located in the western Oregon Coast Range. The site preparation techniques used in these units included scarification, slash burning, and chemical spraying. The ages of the clearcut units studied varied from one to nine growing seasons for the...
More than one-fourth of the forest land in the Pacific Northwest is growing timber at reduced capacity as the result of brush encroachment. Increasing use of chemicals in brush control requires that more information be available regarding their use. Bigleaf maple, Oregon oak and vine maple are among the more...
The experimental setup and data are presented for a laboratory experiment conducted to examine realistic wave forcing on a highway bridge superstructure. The experiments measure wave conditions along with the resulting forces, pressures, and structural response of a 1:5 scale, reinforced concrete model of a typical section of the I-10...
Risk is a crucial decision factor besides traditional cost and performance during collaborative decision making in a distributed environment. Three main challenges exist: 1) stakeholders' different perspectives and/or diverse cultures can lead to inconsistent risk probability evaluations; 2) risk consequence is hard to be quantified in concrete unit; 3) risk...
Three culverts, judged to be fish barriers, were replaced with "stream simulation" culverts on the Fremont National Forest of south central Oregon. The culvert sites are located in the Fort Rock Basin in streams that are home to resident Great Basin redband trout (Oncorhynchus mykiss). Great Basin redband trout is...
A population of Nuttall's cottontails (Sylvilagus nuttallii) in Deschutes County, Oregon, decreased fromm 166 individuals in August 1978 to 76 individuals in August 1979. Survival rates of four annual litter groups in 1978 were 0.74, 0.35, 0.72, and 0.93; survival rates for the same litter groups, respectively, in 1979 were...
Population dynamics, plant communities, and abiotic environments of three narrowly endemic, allopatric mariposa lilies (Calochortus Pursh) are described and compared. All were restricted to ultramafic soils in southwestern Oregon with high concentrations of nickel, zinc, and chromium, and low calcium to magnesium ratios. Soils inhabited by the three species differed...
The successful educator must be cognizant of and accommodate individual learner needs. The mediation of learning between the educator and learner is at the very root of
successful teaching and learning. Recognizing and acknowledging that educators have preferred methods of operation (teaching style preferences) and students have preferred methods of...
My objectives were to: 1) develop a point count technique for estimating relative
abundance of band-tailed pigeons (Columbafasciata monilis), 2) determine the
availability, distribution, and interspersion of mineral sites, and nesting and foraging cover in relation to abundance of band-tailed pigeons in west-central Oregon, and 3) test the hypothesis that...
Sperm competition is the post-copulatory analog of male-male combat, wherein sperm
from more than one male coincide in a female’s reproductive tract and compete with one
another for fertilization of a limited number of ova. Post-copulatory sexual selection,
such as sperm competition, can be a powerful driving force for the...
This paper discusses two main trends in the development of virtual
machine systems: full system virtualization, where an entire hardware
architecture is replicated virtually, and paravirtualization, where an
operating system is modified so that it can be run concurrently with
other operating systems that have also been designed for paravirtualization.
An energy balance analysis was performed on each of four
transplanted Douglas-fir [Pseudotsuga menziesii (Mirb.) Francol
seedlings growing on two cutover sites in southwestern Oregon. The
two sites were a clearcut and a partial-cut (shelterwood) side by
side, with a pair of seedlings used on each site. One seedling of...
Phosphorodiamidate morpholino oligomers (PMOs) are novel antisense drugs in the early stages
of development. These synthetic DNA mimics contain the same bases found in DNA and anneal
to RNA in a complementary fashion. PMOs have been designed that target genes responsible for
producing essential proteins in organisms such as Escherichia...
Maintenance of optimal nutrient supplies is fundamental to the functioning of
vertebrate, invertebrate, bacterial and plant physiology. Organisms on this planet compete
with each other primarily to fulfill nutritional needs in order to maximize their health,
wellbeing, and reproductive success. Here we examine nutrient concentrations in several
different grass species...
Two policies for allocating individual assets from a pool of assets to incoming requests were contrasted within the context of replacement analysis. Assets within a pool are considered similar in the service they provide, but may differ in age and cumulative usage. The two policies considered for allocating assets to...
Inner shelf hypoxia has occurred along the Oregon coast between the latitudes 44ºN
and 45ºN since 2002 with increasing duration and intensity, posing a threat to marine
life. The objective of this research was to determine whether variation in respiration
rate explains spatial and temporal variation in hypoxia. Dissolved oxygen...
The doctor-patient relationship is one of the most unique and privileged relations
a person can have with another human being, and having access to a well-developed and
effective association is important for the experienced and objective quality of health care.
Yet, over the past few decades a number of cultural...
Previous studies have revealed distinctive ecotypic differences between garter snakes living in the meadow and lakeshore environments around Eagle Lake in California. Snakes from these contrasting environments have significantly different growth rates, litter sizes, adult body size, annual survival, and coloration. To try and explain these differences, bird predation was...
Expansion of Juniperus occidentalis into the sagebrush steppe has resulted in significant changes in understory composition. A consequence of increased J. occidentalis dominance may be a depletion of the seed bank. The potential for depletion is problematic because a reduction in the amount of species available from the seed bank...
The doctor-patient relationship is one of the most unique and privileged relations a person can have with another human being, and having access to a well-developed and effective association is important for the experienced and objective quality of health care. Yet, over the past few decades a number of cultural...
Tillage of forest soils compacted by ground-based logging systems is a practice that is becoming widely accepted in the Pacific Northwest. However, past research has failed to adequately define the conditions and specifications that particular tillage operations should meet in order to produce the maximum growth response from planted seedlings....
This study evaluated the recovery of compacted soils on logging
skid trails in clearcuts of the western Cascade Mountains of Oregon.
Soil types included clay, clay loam, silt loam, loam, sandy loam
and loamy sands. Sites ranged in age from five to 38 years since
harvest and 370 to llOOm...
The management of existing forest road systems is an issue of growing importance and public debate. Roads can alter the hydrologic processes in a watershed especially at stream crossing culverts where road ditches channel runoff directly into the stream. The objective of this study was to determine how surface runoff...
Logging road construction in the coastal regions of British Columbia has always been a difficult and expensive undertaking. The soils are generally ill-suited to road construction, rock outcrops are numerous, and climatic conditions unfavourable. In
addition, the mineral soils are overlaid by a heavy layer of partly decomposed organic material....
Oregon's forestry industry has and will continue to be a vital component of Oregon's economy, with twenty-two percent of Oregon's 1986 gross state product and thirty-nine percent of Oregon's 1986 gross manufacturing product related the forestry goods. An integral component to proper management of Oregon's forestry lands is Sustaining the...
Twenty eight countersunk culverts in Oregon were evaluated to assess current conditions and hydraulic performance. The culverts were also assessed with respect to their stability, particularly when subjected to high flows. In general, the culverts were
found to be resistant to erosion and effective at conveying large discharges. Based on...
Many diverse applications have begun to study processes and patterns at a global
scale. To aid in this research, discrete global grid systems (DGGSs) are data models
which enable environmental modeling, monitoring and sampling across the earth at a
variety of spatial scales. A DGGS can be evaluated on a...
Precipitation data from 1988-1995 for 13 rain gauges of the Department of Forest
Engineering rain gauge network, and a longer precipitation record, 1976-1995, at Mapleton were analyzed. The objectives were to assess the spatial and temporal distribution of precipitation intensity and antecedent precipitation, and understand the role of these characteristics...
Modern environmental monitoring and modeling requires a good global
grid system for survey sampling and accurate, spatially complete data
collection of relevant environmental phenomena. A prime requirement for the
global grid system is that the global sampling grids be regular and equal in area
and have minimal shape distortion. None...
Numerous studies have demonstrated that vegetation canopies affect snow
accumulation and ablation processes. In addition, estimates of remotely sensed snow
covered area can be biased by the presence of an overlying vegetation canopy.
Consequently, any attempts to measure, model, or map the distribution of snow in a
region with heterogeneous...
Initially, a small experimental study was undertaken to examine the influence of incline on the frequency of taut cables. The experiments consisted of exciting a short cable at angles of incline from zero to 90 degrees and at various tensions. The results from these experiments shows a small effect due...
Taking advantage of a favorable physical system but also risking the hazards of flooding, man has long occupied flood plain land. He has attempted to adjust rivers to his needs in order to reduce flood loss, but the rising cost of flood protection accompanied by an increase in flood damage...
Several state and federal agencies have identified Oregon's coastal wetlands as
priority areas for conservation, and in some cases have specifically singled out
nontidal (mostly palustrine) wetlands as a major concern. Recent research has
highlighted the need to study and manage wetlands from a regional perspective that
considers the distribution...
A recent surge in the development of irrigated agriculture in
the Fort Rock Basin of the Oregon High Desert has resulted in two
principal types of agricultural operations in the area: cow-calf
operators and cash-crop agriculturalists. The agroclimatic
hazards associated with the present situation and the implications
of those hazards...
The growth of Alnus acuminata (HBK) 0. Ktze, Cupressus
lusitanica Mill., Gmelina arborea Roxb, Pinus caribaea var. hondurensis
Barr. & Golf., and Tectona grandis L. in Costa Rica and
twenty seven soil and climatic factors were analyzed to determine
the relationship between major environmental factors and growth
rates of these...
This study focused on extensive soil mass movement occurrence
in the Willamette National Forest of western Oregon and on intensive
measurements of some physical and biological changes in
streams following debris torrents. Debris torrents are a rapid
movement of water-charged debris confined to steep headwater channels.
The frequency (events/ha/yr) of...
This study compares production rates and costs for four ground skidding machines and for four harvesting treatments. The four
machine types studied were a Caterpillar 060 crawler (060), Caterpillar 518 rubber tired skidder (RTS), FMC 200 CA (FMC), and
International TD-8E crawler (TD-8E). Two treatments, conventional/whole tree and designated/tree length,...
In 1968, Congress passed the Wild and Scenic River Act
creating a system of rivers protected from dams and other
development. By 1987, segments of four Oregon rivers were
protected by the Wild and Scenic River System: the Rogue,
Illinois, Owyhee, and a portion of the Snake along the
Idaho...
Stream buffer strips are an important tool for protecting the stream environment. This research documents the losses from 40 stream buffer strips, in the Western Cascades of Oregon, established 1 to 15 years before the study. Predictive equations are developed
which identify the major reasons for buffer strip losses. Losses...
A spatially explicit population model written in C++ programming language is used in
this study examining the population dynamics of the Desert Tortoise (Gopherus
agassizii) in the California Mojave Desert. The model is constructed with hexagonal
divisions of space, and with one-year increments of time. Four thematic maps: vegetation,
soil...
Soil erosion is a natural physical process. However
it can become a detrimental force when factors such as
infertile soils, steep topography and poor farming
practices are combined. An important initial aspect of
resource planning and/or soil conservation involves
locating areas where such potentially hazardous
combinations occur in the field....
The John Day Reservoir, a large reservoir between the John Day and the McNary Dams on the Columbia River, must be lowered several feet below design level during salmon migration season in order to preserve anadromous fish habitat. This research assessed the north shore of the John Day Reservoir for...
Elk River is a sixth order stream, draining a 200 square
kilometer basin in the Klainath Mountain province of
southwestern Oregon. Timber harvesting began in the basin
during the 1950's, with peak removal of wood occurring in the
mid to late 1960's. This activity lead to an increase in the...
Remote sensing is an attractive method for the
detection and monitoring of crop stress. The feasibility of
using remote sensing for the detection and monitoring of
fungal diseases, insects, weeds, and non-infectious
diseases affecting the cultivated cranberry (Vaccinium
macrocarpon Ait.) is evaluated. A study on the fungal
disease twig blight...
Tourism has become an important factor in Oregon's and
New Zealand's economies. Both destinations are trying to
attract even more tourists. However, many other destinations
are also competing for a bigger share of the tourism market.
Tourism itself is a multi-faceted phenomenon and the travel
destination decision is of some...
This study examined the logbook record of the Oregon trawl fishery using a geographic information system (GIS) to determine the spatial and temporal distribution of English sole, Pleuronectes vetulus. The original logbook data for the years 1981,1982,1994,1995,1996 were filtered twice to provide both a general description of trends in the...
This project examined the harvest patterns found on private forestland in western Oregon (46000 1cm2) between 1972 and 2002. The research addressed hypotheses concerning the behaviors of different classes of owners as defined by total amount of forestland owned. Existing forest stand disturbance data and ownership data were combined using...
This thesis considered current approaches to describing landscape pattern,
identified scale issues associated with defining objects, and explored techniques to
reliably group elements based on land cover as represented by satellite imagery. It
was recognized that there is an important need to develop tools that can be applied
using remotely...
This report derives from two policy work sessions, one in January 2008 and one in May 2008, which explored policy cornerstones
and action strategies to bring an integrated ecosystem marketplace to fruition in Oregon. The report takes an initial look at ways in which
current state policies and practices either...
Windthrow has been studied extensively as a cause of mortality and as a landscape
disturbance agent in temperate forests throughout the United States. The effects of
windthrow mortality on stand species composition and structure, forest regeneration and
seral development have been well described at the site (e.g. single gap) and...
The impacts of modern limited-access highways on the spatial distribution of non-agricultural development, and their influence in the shaping of occupancy patterns, are far-reaching and should be of eminent concern to all Americans. The location of the Interstate routes, with 80 percent of their 41,000 miles crossing rural localities, renders...
This study investigates riparian cover change between 1939 and 1996 utilizing aerial
photography, bank conditions and stream gauge data. Three sites under 1.0 km2, along a 10-
km reach north of Harrisburg, Oregon, were evaluated. The cover classification scheme
included 18 classes composed of 3 canopy densities and 8 structural...
Sediment production and delivery in Pacific Northwest
coastal streams can have damaging effects on channel
morphology and anadromous fish habitat. The research in
Pistol River was designed to determine if a link exists
between sediment delivery processes and degradation of fish
habitat. Objectives of this basin-wide analysis were to:
1)...
The H. J. Andrews Experimental Forest in the Cascades of
central Oregon provides a unique opportunity to study spatial
climate patterns on a relatively small scale. Historical
records at the 64 square-kilometer site provide a spatiallydense
30-year dataset. Thermal regimes at the H. J. Andrews
are generally known but the...
Most aging individuals prefer to remain in a self-determined home environment, and generally aging adults want to remain in the same home or same community. The benefits of remaining in a self-determined private home environment while aging have been established. Because individuals present a diversity of needs, it takes interdisciplinary...
The study of carbonation perception is limited, even though carbonated beverages are very popular. A series of experiments
were conducted to determine the sensory properties of carbonation itself and its interaction with other sensory modalities.
First, the power functions of carbonation in carbonated spring water were developed by a trained...
The purpose of this study is to name and give voice to the spiritual expression of leadership by women community college presidents. The following questions guided the research: (1) How do women community college presidents describe spirituality? (2) How does spirituality convey itself in the reflections, self-expression, and practice of...
The goal of this research is to understand factors influencing the use of TEK in
natural resource management collaborations between tribes and federal agencies. This includes what evidence exists that TEK is being used, what tribal factors influence the use of TEK, what agency factors influence the use of TEK,...
Counselor expectations of supervision and counselor burnout were assessed. The sample consisted of 120 members of the Oregon Personnel and Guidance Association. Subjects were contacted by mail and asked to complete a questionnaire. The questionnaire contained two instruments: the Maslach Burnout Inventory (MBI) and the Counselor Supervision Inventory (CSI). The...
The effect of nitrogen on influencing the competitive balance between a shrub, Artemisia tridentata ssp. wyolningensis (ARTRW) and a perennial grass Stipa
thurberiana (STTH) in a sagebrush steppe community was determined. Nitrogen levels were altered on 5x5 in plots by applying 4.5 gun2 of nitrogen in the form of ammonium...
For resin based dental restorative composites, one of the major challenges is to optimize the balance between mechanical and optical properties. Although fracture is the second leading cause of dental restorative failures, very limited mechanistic understanding exists on a microscopic level. In the present study, the fracture properties and mechanisms...
Summer low-flow behavior in the semi-arid areas of the Pacific Northwest was studied. Long-term data from thirty-eight streams/rivers and thirty-six precipitation stations was exploited. The study area was divided into five zones based on annual average precipitation. Trends and patterns
in summer low-flows and precipitation were identified. Different zones showed...
The minnow genus Siphateles is distributed throughout the Great Basin and adjacent drainages of western North America. Three species are currently recognized in the genus: S. alvordensis, Alvord chub, S. boraxobius, Borax Lake chub, and S. bicolor, the tui chub. S. bicolor has long been recognized as a widespread species...
This study examined the occurrence of coarse woody debris (i.e., pieces greater than 0.15 m in diameter and 2.0 m in length) in first- through fifth-order streams located within the Drift Creek Basin of the Oregon Coast
Range. Nine "tributary reaches" were surveyed to determine how three land management treatments...
A descriptive model of bed material routing was developed for alluvial streams exhibiting sequences of pools and armored riffles. The model assumes that channel geometry, sediment transport competence and the availability of sediments for transport are all non-uniform in the downstream direction. Bedload transport is described as occurring in two...
Harvesting costs were determined for commercial thinning of young stands to
achieve vegetation and wildlife objectives. This included replicated comparisons of
thinning treatments. Treatments were defined based on residual tree stocking after
thinning. Study procedures were developed and evaluated to improve statistical
relevance. Multiple linear regression models were used to...
Fishery biologists and watershed management specialists have recently begun to investigate the pollutional threat posed by organic debris left in or near the forest watercourses. Oxygen content in some streams has fallen below the limits required for fish survival. The biochemical oxygen demand exerted by the debris and the reaeration...
Pool morphology was surveyed in 19 stream sections within the central Oregon Coast Range. Pool locations, sizes, spacings, numbers, and factors affecting pool formation were determined for each stream section. All sections were underlain by sedimentary rocks, had drainage areas ranging from 1.3 to 17.3 km², and had average water...
The energy budget of a pumice desert surface was analyzed under
clear skies during early, mid- and late summer periods. The pumice
site is in the semi-arid plateau region of Central Oregon at an elevation
of about 1500 meters. The flat pumice surface is approximately
250 hectares in extent, and...
The Steamboat Creek basin drains 227 mi² (588 km²) of steep forested terrain into the North Umpqua River of Southwest Oregon, 39
mi (63 km) northeast of Roseburg. Summer base flows for Steamboat Creek average 83 cfs (2.35 m³/sec). Steamboat Creek and its
tributaries are considered important to the production...
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...