The spreadsheet has become a common technology tool and is now a predominant form of end-user programming. Some of the same features that make spreadsheets excellent tools for ad-hoc development can introduce errors into the final product. Although a variety of research has been performed investigating methods to detect errors...
This dissertation is about statistical methods for data analysis using generalized linear mixed models (GLMMs) with censored covariates. Special attention in given to the particular problem of inference about age-specific reproductive success in wild animal populations using some animals with known ages and some animals with ages only known to...
Business is a social institution and society has always designated a role for
business which has been undergoing changes with changing societal values and
paradigms. Thus while business has always had some responsibilities, the modern
connotation of the words corporate social responsibility commonly refers to business
assuming responsibilities in economic,...
The extreme value index (EVI) links the generalized extreme value (GEV) distribution and the generalized Pareto (GP) distribution. These two distributions are fundamental in extreme value theory (EVT), with the GEV distribution being the only possible non-degenerate limiting distribution of properly normalized maxima of iid random variables, and the GP...
High severity fire is a historical and integral disturbance process in coniferous
forest types. Compounded disturbances such as multiple fires or post-disturbance
management activities are increasingly common, but ecological responses are not well
understood and may represent novel types of disturbances. I studied bird and small
mammal communities in the...
Aquatic ecological investigation is expanding to encompass considerations of
multiple scales across large landscapes. Much of the analysis included in this work
focuses specifically on coho salmon (Oncorhynchus kisutch) in multiple subbasins on
the Oregon coast. Coho salmon were chosen for an investigation of spatial scales,
network connections, and life...
This thesis synthesizes surficial structural data, a detailed analysis of an earthquake in 1944, and historical seismicity into a new model of crustal scale deformation in the eastern Precordillera in northwestern Argentina in the vicinity of San Juan. The eastern Precordillera was uplifted during previous thin-skinned deformation episodes, and is...
For data following a balanced mixed Anova model, the standard Anova method typically leads to exact F tests of the usual hypotheses about fixed effects. However, for most unbalanced designs with most hypotheses, the Anova method does not produce exact tests, and approximate methods are needed. One approach to approximate...
Since the 1964 earthquake and geologic uplift, beavers (Castor canadensis) have expanded their historic range from the inland (outwash plain) Copper River Delta, Alaska to the once tidally influenced areas of the outer area (uplifted marsh). The uplift presents a unique opportunity to observe beaver expansion, habitat selection and influence...
This dissertation is about the likelihood analysis of ordered categorical responses in a longitudinal/spatial study, meaning regression-like analysis when the response variable is categorical with ordered categories, and is measured repeatedly over time or space on the experimental or sampling units. Particular attention is given to the multivariate ordinal probit...
Habitat loss causes a reduction in available resources for wildlife, alters the configuration of remaining habitat, and may isolate wildlife populations. White-breasted nuthatches (Sitta carolinensis) are experiencing long-term population declines in the Willamette Valley of Oregon, where they are historically associated with oak woodlands. As secondary cavity-nesters, white-breasted nuthatches may...
Regression calibration inference seeks to estimate regression models with measurement error in explanatory variables by replacing the mismeasured variable by its conditional expectation, given a surrogate variable, in an estimation procedure that would have been used if the true variable were available. This study examines the effect of the uncertainty...
Lichens are an important part of the biota in western Oregon forests, where
they perform valuable ecological roles and contribute significantly to biodiversity.
Lichens in western Oregon are threatened by a number of factors including air
pollution and land use practices. If we wish to maintain the persistence of lichens...
Effects of whey concentrate crystallization parameters of temperature, pH, and length of time of crystallization on lactose crystal forms and amount of lactose crystallized were investigated. Effect of crystallization parameters on freeze-dried powder quality was also investigated. Lactose crystal forms were observed in x-ray crystal diffraction patterns of freeze-dried whey...
This dissertation describes the development of a new sustained release formulation of nifedipine. The new formulation was developed by coating commercially available immediate release soft elastic gelatin capsules using a spray coating technique with two different polymeric combinations. Dissolution studies were conducted and showed that controlled release of nifedipine was...
I investigated the relationship between harlequin duck (Histrionicus histrionicus) behavior and lack of recovery from the Exxon Valdez oil spill in Prince William Sound, Alaska. First, I evaluated the hypothesis that harlequin ducks in winter have little flexibility to increase foraging time in response to disturbance because they are constrained...
With increased resource development on the western Arctic coastal plain of Alaska (especially within the oil extraction industry) it is important to understand the basic life history attributes of whitefish stocks in the region in order to ensure appropriate management. These fish are a crucial part of subsistence harvests for...
Index counts for the Pacific Coast race of the band-tailed pigeon (Columba fasciata monilis) have declined by -2% per year since survey efforts began in the 1950's and 60's. Mineral sites, important resources with high ion concentrations, are regularly visited by band-tailed pigeons which nest in surrounding forest lands. I...
The purpose of this study was to investigate the survival and movements of newly metamorphosed Northern Red-legged frogs (Rana aurora aurora) as they emigrated from two ephemeral breeding ponds. Quantifying survival and movement rates will be important to our understanding how changes to terrestrial and aquatic systems affect behavior and...
In this study we use a combination of data from forest inventories,
intensive chronosequences, extensive sites, and remote sensing, to make estimates
of biomass and net primary production (NPP) for the forested region of Western
Oregon. Plot-level forest inventory data were provided by the USDA Forest
Service through their Forest...
Small remnants of 'natural' habitats exist today throughout much of the world. Upland prairies in the Willamette Valley, Oregon have been nearly eliminated by conversion to agriculture and other uses. As a result, very few prairies remain and at least four butterfly species that require this habitat appear to be...
Alfalfa accumulates phytoestrogens and when ingested binds the estrogen receptor and induces morphological changes similar to endogenous estrogens. The objective of this study is to evaluate morphological changes in uteri, vulva, and teats of ovariectomized prepubertal ewe lambs. Eighteen prepubertal ewe lambs were ovariectomized in November 2000 and fed nonestrogenic...
Two vintages of Vitis vinifera cv. Pinot noir wine from a viticulture trial evaluating nitrogen fertilization, tilling and irrigation underwent descriptive analysis using a modified version of free-choice profiling. Wines were made from three field blocks of the twelve factorial combinations of Irrigation (Dry or Irrigated), Tillage (Tilled or not...
Staling in beer is inevitable. Oxidation and increased temperatures are the main causes of stale flavors in bottled beers. Since 1934, research has been done to identify compounds and pathways involved in creating stale flavors. Although many research papers report stale flavors, there is not a lexicon per se of...
Ecologists have long questioned why fluctuating populations tend to persist rather than go extinct. Populations that persist indefinitely are regulated by mechanisms that cause demographic density dependence, which works to bound fluctuation above zero. In a series of studies, I have sought to determine the processes and mechanisms that regulate...