The disposition of four therapeutically important antimicrobial agents was studied in llamas following intravenous bolus administration. Six llamas were each given ampicillin, tobramycin, trimethoprim and enrofloxacin at a dose of 12 mg/kg, 1 mg/kg, 3 mg/kg and 5 mg/kg of body weight with a wash out period of 3 days...
Seasonally, in 1998 and 1999, I examined spatial and temporal variation in fish assemblages of agricultural, forested, and acid mine drainage tributaries within the Wayne National Forest (WNF) in southern Ohio. Land use and natural disturbance explained patterns in stream fish assemblages. Creek chub and green sunfish were present in...
I used a comparative and experimental approach to examine nest habitat selection, reproductive success, and nest site fidelity of burrowing owls (Athene cunicularia) in a large, non-fragmented grassland in southwest California. In 1999, I compared habitat characteristics between nest sites (n = 31) and randomly selected, unoccupied burrows (n =...
In cross-cultural studies, respondents from specific cultures may have different product preferences and scale usage. Combining data from different cultures will result in departures from the basic assumptions of analysis of variance (ANOVA) and loss of power in testing capability of finding product and culture differences. However, the result of...
I conducted acoustic lure surveys of northern pygmy-owls (Glaucidium gnoma) on transects that were systematically placed in forested areas throughout the state of Oregon. My objectives were to determine if pygmy-owls were associated with particular forest types, ecoregions, or with large-diameter dominant overstory trees. I also examined temporal variation in...
The purpose of this study was to investigate the primary factors affecting colony size, reproductive success, and foraging patterns of Double-crested Cormorants (Phalacrocorax auritus albociliatus) nesting at East Sand Island in the Columbia River estuary, the largest colony of this species on the Pacific Coast of North America. This colony...
Although widely studied in many portions of North America, little is known about the specific habitat requirements of mallard ducks (Anas platyrhynchos) during the breeding season in western Oregon. I radio-marked 72 female mallards in the Willamette Valley of Oregon in March-April 1995-96 to document wetland habitat selection during pre-nesting...
The ability to non-destructively assess fish condition and subsequently track fish behavior and survival can be vital in understanding natural and anthropogenic stressors and sources of mortality, especially in populations of fish listed as threatened or endangered. I investigated the use of a quick, non-lethal, external examination technique to assess...
Recent studies suggest that competition from brook trout (Salvelinus fontinalis; EBT) may have negative effects (e.g. displacement) on Lahontan cutthroat trout (Oncorhynchus clarki henshawi; LCT). Results from these studies have failed to elucidate the responsible mechanisms and have not examined if changing environmental conditions result in competitive/subordinate role reversals. The...
North American sagebrush (Artemisia spp.) ecosystems are suffering from
reductions in habitat extent and quality. Only about 50% of sagebrush remains
from pre-settlement conditions, and much of the remaining habitat is
fragmented or degraded by invasive species, fire suppression and overgrazing.
Sagebrush-obligate species are experiencing population declines as a result...
I studied bird and rodent nesting in woodpecker-excavated
cavities in pifion-juniper (Pinus edulis-Juniperus monosperma) (P-J)
woodland in southeastern Colorado during the spring and summer of 1987
and 1988. Two related investigations were conducted: one described
characteristics of habitat used by birds and rodents nesting in
woodpecker-excavated cavities and the other...
The average size and age of chinook salmon (Oncorhynchus
tshawytscha) caught in commercial fisheries along the Pacific Coast
of North America have decreased substantially in this century. These
declines might be caused in part by changes in size and age at
maturity within the stocks contributing to those fisheries. Upriver...
This thesis examined the influence of fall-spawning coho salmon on the density, growth rate, body condition, and survival to outmigration of juvenile coho salmon rearing in beaver ponds on the Copper River Delta, Alaska. During the fall of 1999 and 2000 fish rearing in ponds that received spawning salmon were...
Asian countries have become one of the largest export markets for US food developers during the past decade. Understanding consumer expectations and needs in a cross-cultural framework has gained importance for new products to succeed in the international markets. A sports-drink, which is a functional drink for athletes, has been...
The aroma of milk has been often defined as bland and pleasant, yet characteristic. Conventional thermal processing of milk can certainly extend shelf life, but inevitably changes its flavor. High pressure processing has been suggested as an alternative for milk pasteurization with improved fresh flavor retention. The objective of this...
I examined the avian biogeography of the islands of Lago Gatun, Panama, in an effort to better understand the effects of forest fragmentation in this biodiverse region, and specifically to understand the importance of fragment isolation and the mechanism behind its effects on tropical bird distribution. I combined exhaustive surveys...
Hop aroma in beer is related to the unique compositional chemistry of the hops used in the brewing process. While the range of these compositions is quite diverse and primarily dependent on hop cultivar¹, other studies have also shown that cultivation, seasonality, harvesting², processing³⁴, and storage practices⁵⁶ contribute to differences...
While water scarcity and energy demand are continuously increasing in the world, alternative sources are needed to meet the requirement of a growing population. Microbial Fuel Cell (MFC) is a sustainable technology that converts organic matter in wastewater into electricity, thus it can be a potential alternative source for water...
Data in the form of counts or proportions often exhibit more
variability than that predicted by a Poisson or binomial
distribution. Many different models have been proposed to account
for extra-Poisson or extra-binomial variation. A simple model
includes a single heterogeneity factor (dispersion parameter) in the
variance. Other models that...
Quantitative habitat models of wildlife-habitat relationships are developed to
formalize our current understanding about an ecological system. A habitat
association model is one of these models that is useful for answering questions
about how the habitat is occupied, how much growth habitat is required by the
animal, or how the...
Nest sites of reticulate sculpin (Cottus perplexus) were located in two stream reaches, one from a basalt basin and one from a sandstone basin. Stream reaches were similar in gradient, basin area, elevation, climate, and riparian vegetation but differed in biologic community structure and substrate characteristics. An electivity index was...
Environmental monitoring poses two challenges to statistical analysis: complex data and complex survey designs. Monitoring for system health involves measuring physical, chemical, and biological properties that have complex relations. Exploring these relations is an integral part of understanding how systems are changing under stress. How does one explore high dimensional...
The 1989 Exxon Valdez oil spill was a major perturbation of nearshore habitats of Prince William Sound, a wintering area for harlequin ducks (Histrionicus histrionicus). This research was designed to evaluate harlequin duck population recovery from the oil spill from 1995 to 1998, using a demographic approach to assess both...
Lemon oil quality is affected by numerous factors including lemon variety, climate,
soil type, extraction method, etc.. Therefore, quality largely depends upon the lemons'
origin, and aroma profiles of oils obtained throughout the world have potential to vary
considerably. This research was conducted to identify differences in the aroma profiles...
Texture, a critical property of Asian wheat noodles, is normally assessed by
sensory evaluation. However, sensory evaluation may be impractical for wheat breeders
and noodle researchers who need to evaluate a large number of samples and have limited
sample. Instrumental Texture Profile Analysis (TPA) has been widely employed to
evaluate...
Chipping varieties and model systems were used to determine the role of potato
constituents on chip color. Composition was evaluated by HPLC and chip color
measured using a ColorQuest colorimeter. Reducing sugar (RS) content did not
completely explain color quality when present in low concentrations (<60 mg/lOOg).
Levels of ascorbic...
To assess the consequences of increased recreational activity on bald eagles (Haliaeetus leucocephalus), we studied factors that influenced their behavior and reproductive success in the Gulkana River basin, Alaska, from 1989 to 1993. Both extrinsic and intrinsic factors were associated with reproductive success. Productivity averaged 0.86 young fledged per occupied...
In this study an analysis of the commercial fishery of the Loreto Region, with emphasis on the fishery fleet of Iquitos, Amazon Basin, Peru, is presented. There is evidence of a progressive replacement of large species by smaller, more productive and lower value species in the landing of the commercial...
Since the early 1990s, declines in northern spotted owl (Strix occidentalis caurina) populations have been documented through extensive field surveys and range-wide demographic analyses. Although loss of late-successional forest has been credited as the primary cause for spotted owl population declines, environmental variation has also been shown to influence vital...
Frozen blueberries were pilot-plant-processed into juice and concentrate by 2 treatments (heat and SO2), and a control. Qualitative, and quantitative anthocyanin and polyphenolic content were monitored after each processing step. Major losses occurred after the initial processing steps. Juice processing by-product contained a substantial amount of anthocyanins and polyphenolics (>42%...
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...
Populations of coastal cutthroat trout, Oncorhynchus clarki clarki, were sampled in 16 headwater streams from logged (20-30 and 40-60 years ago) and unlogged (stand age 125-150 years) basins. Basins logged 20-30 years ago supported the widest range of mean biomass of age 1+ or older cutthroat trout (g/m2) and the...
The ecology of female mallards (Anas platyrhynchos) and their
broods was studied during 1988-90 on Lower Klamath National Wildlife
Refuge, California. Survival of 127 radio-marked ducklings from 64
broods was 0.18 to 10 days of life, and 0.37 and 0.34 to fledging for
1988, 1989, and 1990, respectively. For the...
Concerns have been expressed that wheat (Triticum aestivum L.) cultivars selected under optimum conditions may lack adequate adaptation for stress environments. Experimental populations were grown under three environmental conditions 1) optimum, 2) reduced irrigation, and 3) high temperature. Field experiments were conducted at the Center for Northwest Experimental Station (CIANO),...
Mycosphaerella graminicola (anamorph Septoria tritici) causes Septoria tritici blotch, a globally important disease of winter wheat. Resistance and pathogenicity generally vary quantitatively. The pathogen reproduces both sexually and asexually, and the pathogen population is highly genetically variable. Several unresolved questions about the epidemiology of this pathosystem are addressed by this...
We monitored larval Lost River and shortnose suckers from natal beds in the Williamson and Sprague rivers to nursery grounds in Upper Klamath Lake. Downstream movements occurred at night, in the middle of the channel, and on the falling limb of the hydrograph. Ages, sizes, and developmental stages of larvae...