Beer brewing, broadly speaking, consists of two stages, a hot side and a cold side. The hot side occurs in the brewhouse and consists of steeping malted grain in hot water to extract sugars, separating the steeping liquid (wort) from the solids, and boiling the wort with an addition of...
The biotransformation of hop aroma via yeast is a prominent topic in the brewing industry with considerable interest placed on how yeast can enhance volatile thiol production during wort fermentation. Three potent thiols are known contributors to tropical qualities in wine and beer aroma, specifically 3-mercaptohexan-1-ol (3MH), 3-mercaptohexyl acetate (3MHA),...
In short, the brewing process uses hot water to extract fermentable sugars from malt to make a wort that is bittered by hops and finally fermented by yeast to produce beer. The four key ingredients in brewing are malt, water, hops, and yeast. Malt is perhaps the key ingredient, as...
Kilning, which is the drying operation in hop cultivation, is a processing step that can have a tremendous impact on hop quality. Historically, hops have been dried at temperatures ranging from 140-155°F. In the last decade, growers have moved toward kilning hops at lower temperatures averaging between 125-140°F in the...
Hop powdery mildew (Podosphaera macularis) was confirmed in the Pacific Northwest in 1996. Before 2012, the most common race of P. macularis was able to infect plants that possessed powdery mildew resistance based on the R-genes Rb, R3, and R5. Post 2012, two additional races of P. macularis were discovered...
According to conventional wisdom, hops are treated in the brewery as biologically inactive ingredients, added to wort or beer primarily as a flavoring agent. In the past, hops were used in relatively small quantities, with the majority of hop additions made to boiling wort. Converse to traditional hopping practices, modern...
Hops (Humulus lupulus L.) are primarily used to provide specific characteristics to beer, such as bitterness, aroma, flavor, and microbial stability. The chemical composition of hops, relative to how they are used during the brewing process, dictates the expression of these characteristics. Of the raw ingredients that go into making...
Wine grape pomace (WGP), the byproduct from winemaking, is a good source of polyphenols and dietary fibers, and may be utilized as antioxidant dietary fibers (ADF) for food applications. The objectives of this thesis research were to first determine the phenolic compounds, antioxidant and antimicrobial activities in red WGP under...
This work set out to examine the methodologies of dry hopping, compare different hop materials, and look at the extraction behavior of different types of hop compounds. This work consists of two discrete studies, where the first study informed the design of the second.
The first study measured the concentrations...
The popularity of hop-forward American craft beers has had a profound impact on the use of hops as an ingredient; where hops were once thought of as the “spice” of beer, they may now be considered the primary driver of flavor in beer styles such as American India Pale Ales....
Green bean flavor has been studied since the 1960’s to better understand Blue Lake flavor in processed green beans in Oregon. Research by Stevens and colleagues showed that Blue Lake flavor could be reconstituted in a bland bean by adding 0.4ppm of 1-octen-3-ol and 1.6ppm of 3-hexen-1-ol. These two volatile...
When hops are added to beer, varying degrees of hoppy aroma persist in the finished beer as a result of a number of factors. Dry-hopping is a technique whereby hops are added to beer post-fermentation to leverage the maximum aroma potential of the hop essential oils while minimizing bitterness contribution...
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...
Myxozoans are microscopic parasites, related to corals and jellyfish. Most Myxozoa probably have two-host lifecycles that require a vertebrate (typically fish) and invertebrate (annelid or bryozoan). However no life cycle is known from the Sphaerospora lineage.
I hypothesized that the life cycle of Sphaerospora elegans, a myxozoan parasite of three-spined...
In the Middle Rio Grande region of New Mexico, challenges such as droughts, growing urban demand for water, and newly listed endangered species have forced people to change the way that they manage water. New challenges in water governance have created cooperation among agencies that often have conflicting interests, goals,...
Habitat loss and fragmentation is a crisis affecting wildlife worldwide. In Tanzania, East Africa, a dramatic and recent (<80 years) expansion in human settlement and agriculture threatens to reduce gene flow among protected areas for many species of large mammals. Wildlife linkages can mitigate population isolation, but linkage designs lacking...
Many marine fish populations are severely declining due to over-fishing, loss of both juvenile and adult habitats, and accelerating environmental degradation. Fisheries management and the implementation of marine protected areas (MPAs) and other conservation tools are currently hindered by large gaps in knowledge about larval dispersal and its subsequent effects...
Starch is a significant component of the human diet and the glucose produced through its digestion provides a critical source of energy. When starch enters the mouth, salivary α-amylase hydrolyzes it into maltooligosaccharides (MOS, degree of polymerization [DP] 3-20) and maltopolysaccharides (MPS, DP >20). Previous studies have found that humans...
The production of Cheddar cheese is a complex process with multiple potential sources of undesirable bacteria, including those that have negative impacts on product quality (spoilage organisms) and those that are used to evaluate sanitary conditions in the production environment (indicator organisms). The dairy industry commonly uses coliform bacteria as...
This Thesis examines Brazil’s political and historical context to explore and understand the logics behind the high rates of violence in our society. It focuses in education as one of our main vehicles of disseminating knowledge and therefore culture, language and values that might be contributing and perpetuating sexism, racism,...
The purpose of this grounded theory mixed methods study is to understand how new scuba dive students are creating meaning of their relationship to the marine environment and how that might be shaped by dive training and dive experiences. Eighty-one scuba dive students enrolled in a standardized entry-level dive course...
Honey wine, also known as mead, is one of the oldest alcoholic beverages known to man. Made primarily from honey, water, and yeast, this beverage has recently been experiencing a resurgence in popularity. It is imperative that commercial producers focus on consistently creating quality products to differentiate themselves from competitors...
The solution chemistry and kinetic behavior of hafnium peroxy sulfate solutions ("HafSOx") is described in terms of peroxide content and solution speciation. Additionally, thin film behavior, including thermal behavior and solubility, is characterized, and a mechanism of patterning is presented, as well as parameters that should be considered when looking...
Parasites are ubiquitous members of ecological communities, capable of contributing to the decline of vulnerable populations. Therefore, monitoring parasite level is a critical component for host management. Molecular tools, such as quantitative polymerase chain reaction (qPCR), can be valuable additions to monitoring protocols that assess parasitic disease risk to hosts....
The Cackling goose (Branta hutchinsii minima) population has increased from a low of 20,000 in 1984 to the current population of 220,000-300,000 (Stehn 2012, Sanders 2013). As the Cackling goose population began to recover in the late 1990s, the majority of the population relocated from wintering in California to the...
When it comes to carbohydrate, it has been assumed that only mono- and disaccharides, but not oligo- and polysaccharides, can be tasted. However, because of its importance in the human diet, oral detection of starch or its hydrolysis products would be beneficial. The main goal of this study was to...
The objectives of this project were to investigate the critical factors impacting the physicochemical and antibacterial properties of β-chitosan based films derived from jumbo squid (Dosidicus gigas) pens, and to evaluate the feasibility of improving water solubility of β-chitosan through Maillard reaction. The studies examined the effect of molecular weight...
Invasive species are a major threat to global biodiversity. Understanding the mechanisms underlying successful invasions is imperative for developing effective management strategies. Plasticity in physiological, morphological, and behavioral traits could be an indicator of invasion potential in non-native species. The invasive American bullfrog (Lithobates catesbeianus) has recently been observed breeding...
Glioblastoma is the most malignant primary brain tumor with the average
patients surviving only one year after diagnosis, even with aggressive therapy. The
formation of numerous micro-tumors dispersed into the brain due to rapid invasion of
tumor cells, presents the primary challenge to the surgical removal of tumors and
limits...
Oceanic crust covers nearly 70% of the Earth's surface, of which, the upper,
sediment layer is estimated to harbor substantial microbial biomass. Marine crust;
however, extends several kilometers beyond this surficial layer, and includes the
basalt and gabbro layers. In particular, the basalt layer has high permeabilities which
allows for...
Myoglobin (Mb) was extracted from Pacific sardine and added to Pacific whiting surimi to measure its effects on protein gelation. The purity of Mb extract was determined by SDS-PAGE. Mb extracted using ethanol showed higher purity than Mb extract using ammonium sulfate. The addition of 0.2% Mb significantly reduced breaking...
Exotic ponderosa pine (Pinus ponderosa Doug. ex Lawson) plantations are being planted within the natural distribution area of cordilleran cypress (Austrocedrus chilensis (D.Don) Pic. Ser. et Bizzarri) in Patagonia, Argentina. The productivity of these exotic plantations is much greater than that of native forests, suggesting greater water use. Before these...
River basins provide essential services for both humans and ecosystems. Understanding the connections between ecosystems and society and their function has been at the heart of resilience studies and has become an increasing important endeavor in research and practice. In this dissertation, I define basin resilience as a river basin...
The semi-arid sagebrush steppe ecosystem is one of the largest biomes in
North America. The steppe provides critical habitat and forage for wildlife and is
economically important to recreation and livestock industries. However, the ecosystem
is threatened primarily due to several negative effects associated with expansion of the
exotic annual...
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David A. Pyke Patricia S. Muir
The semi-arid sagebrush steppe ecosystem is one of
Caenorhabditis elegans is arguably the best understood animal on the planet.
Used for over 50 years to study development, we have a vast amount of knowledge of
the inner workings of this worm. Our knowledge is incomplete, however, without
placing this organism in its evolutionary and ecological context. In this...
Attempts to develop dual-purpose durum wheat cultivars for both pasta and bread-making
have been unsuccessful. To better understand this limitation, thirty durum
genotypes, selected based on their diverse geographical origin, and five bread wheat
cultivars were compared as to their flour mixing properties, dough physical characteristics
and baking performance. The...
Pheromones are chemical cues produced by organisms that affect the behavior and/or physiology of conspecifics. The orchestration of reproductive behaviors in many animals depends on the expression of sex pheromones. In insects, intraspecific variation in sex pheromone expression is commonly observed and often influences social interactions between individuals. To what...
Daily cyclical changes of light are brought on by the axial rotation of the Earth while seasonal changes in light are caused by Earth’s tilt as it revolves around the sun. Major life history traits, such as development, which are tied to metabolic processes, have a strong link to the...
Polyoxometalates (POMs) are anions consisting of three or more early transition metals ™ (Gr V and VI) oxoanions (in their highest oxidation state) linked together by a shared oxygen bond to form a 3D framework. Polyoxometalates (POMs) are a rapidly growing class of metal oxo clusters with a wide range...
Racehorses are elite athletes that undergo repetitive stresses from jogging, cantering, and galloping exercises, and there is significant evidence that the majority of racehorse musculoskeletal injuries are due to repetitive stress or overuse. Musculoskeletal injuries have negative consequences on the racing industry through the loss of use or death of...
Under the label “Supported Employment,” services that promote competitive, integrated employment (CIE) for working-age adult with intellectual and developmental disabilities have been federally funded since the 1980s, alongside other more traditional day habilitation and segregated or sub-minimum wage employment services. However, since the early 2000s, over 30 states have adopted...
Structure-property relationships have always underpinned the field of solid state chemistry; dependable structural descriptions are integral to understanding and controlling the physical properties of inorganic compounds old and new. While a handful of crystal structures are celebrated for their versatility, flexibility, and functionality, the existence of more exotic structures is...
Analytical chemistry is an area of chemistry primarily focused on the study and use of instruments for separation, identification, and quantification of an analyte of interest. Specifically, separation science within analytical chemistry often refers to the process of dividing mixtures into their small component parts based on differences in their...
Research on the population genetics of microbial organisms requires the use of specialized analyses designed for clonal organisms to avoid violating the assumptions of traditional population genetic models. The tools necessary for performing these analyses existed as a set of unrelated software with non-overlapping capabilities and did not cover all...
There are presently two successful methods used to refine fish muscle proteins: surimi and fish protein isolate (FPI). Both surimi and FPI have the ability to form an elastic gel upon comminution and heating. However, their gelation behaviors are different as they are refined in a biochemically opposite way based...
The number of international inbound tourists to the United States has risen steadily. To serve these and other tourists best, traffic signs need to communicate information correctly across a potential language barrier. Of particular interest is the traffic sign intended to communicate directions to Tourist Information centers. While the general...
The primary objective of this study was to develop methods for
the selection of temperature sensitive division (TSD) mutants of
Chlamydomonas reinhardtii. Such methods were developed and four
temperature sensitive (TS) mutants were isolated and partially
characterized.
Wild type (WT) cells of the plus mating type were synchronized
by a...
Juvenile English sole (Parophrys vetulus) were
collected in Yaquina Bay, Oregon from January, 1986 to
March, 1987. Recruitment of young-of-the-year sole
occurred from January to June, 1986 and again from
December, 1986 to February, 1987. Emigration from Yaquina
Bay started in September, 1986, but a small portion of the
English...
The basic objective of this investigation was to identify and to
examine factors determining the volume of imports of inshell and shelled
Brazil nuts in major importing countries: the United States, the
Federal Republic of Germany and the United Kingdom.
The approach followed involved the construction and analysis of
an...
The main objective of this study was to offer an alternative methodology for
forest sector modeling in developing economies. To this effect, a policy preference
function was developed and estimated using data from the forest sector of the Cote
d'Ivoire.
The justification for this alternative framework for forest sector analysis...
Pacific sardines (Sardinops sagax) are an economically and ecologically important forage fish which transfer energy from planktonic primary producers and secondary consumers to upper trophic predators. Previous genetics studies of Pacific sardine suggested a panmictic population with a shallow genetic structure. However, more than one subpopulation within the Central California...
My thesis explored the effects of environmental variability on population
dynamics and community composition of aquatic insects. Environmental variability in
the form of flow regime in streams can limit the distribution and life-history traits of
aquatic insects. I used tributaries to the McKenzie River in Oregon with dramatically
different flow...
Since bulk p-CuO/n-ZnO heterocontacts were first proposed for gas detection, rapid development has taken place in improving the overall functionality of these structures. While bulk heterocontacts have been shown to exhibit desirable sensitivity and selectivity characteristics, these devices suffer from innate diffusion and ZnO/CuO connectivity drawbacks that limit their effective...
How complex traits evolve continues to be a major focus of evolutionary
investigation. A current topic of debate is the hypothesis that the phenotypic
integration of complex traits gives rise to evolutionary constraints. I studied two color
traits in the common garter snake, Thamnophis sirtalis, that show a high level...