Even after 140 years without a fire, mixed-conifer forest such as Teakettle’s Experimental Forest has a
distinct patch pattern and complex structure. Researcher Malcolm North and colleagues examined the
structure and function of these ecosystems and their response to widely used restoration treatments.
Collectively the studies found fire was essential...
Francisella tularensis is a gram-negative facultative intracellular
coccobacillus that primarily infects macrophages. The causative agent of tularemia,
this bacterium is considered among the most infectious organisms known, requiring
fewer than ten organisms to cause disease. Although ubiquitous in nature,
transmission to humans is rare but can occur via insect bites,...
The photolysis of the aqueous thymine system has been investigated
at 214 nm, 229 nm and 254 nm at room temperature. Products
of photolysis have been identified as hydrogen peroxide, 6-hydroxy-5-
hydroperoxy thymine and tentatively 5-hydroxy-6-hydroperoxy thymine.
These together with thymine loss, were determined quantitatively
under a variety of conditions....
Fluorescence of adenine, guanine, thymine, cytosine, and uracil
has been detected at room temperature in neutral aqueous solution
using a digital signal accumulation technique and right angle fluorescence
detection from solutions with absorbances between 0. 4 and 0. 7.
The quantum yields are respectively 2.6 x 10⁻⁴, 3.0 x 10⁻⁴,...
Mechanical thinning and prescribed fire are widely used to restore western forests after a century of fire suppression, yet we know little about
how these treatments affect understory communities where plant diversity is highest. We followed understory plants and environmental factors in
old-growth, Sierran mixed conifer for two pre-treatment and...
Mechanical thinning and prescribed fire are widely used to restore western forests after a century of fire suppression, yet we know little about how these treatments affect understory communities where plant diversity is highest. We followed understory plants and environmental factors in old-growth, Sierran mixed conifer for two pre-treatment and...
Mechanical thinning and prescribed fire are widely used to restore western forests after a century of fire suppression, yet we know little about
how these treatments affect understory communities where plant diversity is highest. We followed understory plants and environmental factors in
old-growth, Sierran mixed conifer for two pre-treatment and...
We compared the abundance, diversity, and composition of truffles in riparian and upland areas within a
mixed-conifer forest of the Sierra Nevada of California. We sampled for truffles in a single watershed over two seasons
(spring and summer) and 4 years to determine whether truffles were more abundant and diverse...
Previous research has shown that activated carbon is effective
in inactivating certain herbicides applied as a preemergence treatment.
Studies were conducted in the greenhouse to determine the
influence of various factors on the ability of activated carbon to
inactivate herbicides applied after carbon application. Field studies
were conducted to determine...
Influence of temperature and wood moisture content on
spore germination and colonization of Douglas-fir
(Pseudotsuga jnenziesii) heartwood by Poria carbonica
basidiospores and chlamydospores was studied. Both spore
types germinated and colonized wood at moisture contents
above the fiber saturation point, but not below.
Germination and wood colonization occurred at 22°C...
Prescribed burning and mechanical thinning are used to manage fuels within many western North American forest ecosystems, but few studies have examined the relative impacts of these treatments on forest wildlife. We sampled northern flying squirrels (Glaucomys sabrinus) and microhabitat variables in burned, thinned and control stands of mixed-conifer forest...
Prescribed burning and mechanical thinning are used to manage fuels within
many western North American forest ecosystems, but few studies have examined the relative
impacts of these treatments on forest wildlife. We sampled northern flying squirrels
(Glaucomys sabrinus) and microhabitat variables in burned, thinned and control stands of
mixed-conifer forest...
In many western North American forests, prescribed burning and mechanical thinning are widely used to reduce
fuels and restore stand conditions after a century of fire suppression. Few studies have followed the relative impacts
of these treatments on the production and consumption of truffles in forest ecosystems, particularly in the...
In many western North American forests, prescribed burning and mechanical thinning are widely used to reduce
fuels and restore stand conditions after a century of fire suppression. Few studies have followed the relative impacts
of these treatments on the production and consumption of truffles in forest ecosystems, particularly in the...
Nitrogen is a limiting resource in many temperate forests and nitrogen-fixing plants are usually limited to the early
stages of post-disturbance succession. In fire-dependent Sierra Nevada forests, however, Ceanothus cordulatus is
relatively abundant even in old-growth forest conditions which are at least partly maintained by fire.We conducted
a field experiment...
Nitrogen is a limiting resource in many temperate forests and nitrogen-fixing plants are usually limited to the early stages of post-disturbance succession. In fire-dependent Sierra Nevada forests, however, Ceanothus cordulatus is relatively abundant even in old-growth forest conditions which are at least partly maintained by fire. We conducted a field...
In Sierra Nevada forests, shrubs are considered strong soil moisture competitors with regenerating trees, reducing seedling establishment, and
slowing growth. Recent studies, however, suggest that in some circumstances shrubs can facilitate tree establishment and growth by modifying
harsh microclimate conditions; increasing acquisition of water, carbon, and/or nutrients via shared mycorrhizal...
In Sierra Nevada forests, shrubs are considered strong soil moisture competitors with regenerating trees, reducing seedling establishment, and
slowing growth. Recent studies, however, suggest that in some circumstances shrubs can facilitate tree establishment and growth by modifying
harsh microclimate conditions; increasing acquisition of water, carbon, and/or nutrients via shared mycorrhizal...
The diets of a fungal specialist, northern flying squirrel (Glaucomys sabrinus (Shaw, 1801)), and a dietary generalist,
lodgepole chipmunk (Neotamias speciosus (Merriam, 1890)), were examined in the old-growth, mixed-conifer forest
at the Teakettle Experimental Forest in California’s southern Sierra Nevada. Spores of fungi were identified from fecal
pellets collected from...
We examined the nest-tree preferences of northern flying squirrels (Glaucomys sabrinus) in an old-growth,
mixed-conifer and red fir (Abies magnifica) forest of the southern Sierra Nevada of California. We tracked 27
individuals to 122 nest trees during 3 summers. Flying squirrels selected nest trees that were larger in diameter
and...
Forest managers have little information of the effects of common restoration treatments, thinning and burning, on dead woody material (DWM) dynamics in fire-suppressed forests. Fine woody debris (FWD; 0.6–29.9 cm), coarse woody debris (CWD; ≥30.0 cm), and snags (≥5 cm) were inventoried and mapped in eighteen 4 ha plots before...
Soil respiration is a major pathway for carbon cycling in terrestrial ecosystems yet little is known about its response to natural and
anthropogenic disturbances. This study examined soil respiration response to prescribed burning and thinning treatments in an old-growth, mixedconifer
forest on the western slope of the Sierra Nevada Mountains....
Soil respiration is a major pathway for carbon cycling in terrestrial ecosystems yet little is known about its response to natural and
anthropogenic disturbances. This study examined soil respiration response to prescribed burning and thinning treatments in an old-growth, mixedconifer
forest on the western slope of the Sierra Nevada Mountains....
Soil respiration is a major pathway for carbon cycling in terrestrial ecosystems yet little is known about its response to natural and
anthropogenic disturbances. This study examined soil respiration response to prescribed burning and thinning treatments in an old-growth, mixed-conifer
forest on the western slope of the Sierra Nevada Mountains....
Frankia strains symbiotic with Ceanothus present an interesting opportunity to study the patterns and causes of Frankia diversity and distribution within a particular host infectivity group. We intensively sampled Frankia from nodules on Ceanothus plants along an elevational gradient in the southern Sierra Nevada of California, and we also collected...
Triphenylmethyl dye cyanides have been known to be sensitive to ultraviolet radiation since early in this century. Under appropriate conditions, exposure to uv leads to heteropolar fission of the C-CN bond (photoionization) and intense coloration due to dye formation. Thin homogeneous films of hexahydroxyethyl pararosaniline cyanide in a nylon matrix...
The formation of cytosine hydroperoxide was detected in
aqueous cytosine solutions irradiated with Co-60 γ-rays at pH 2.
The nucleotide of cytosine, cytidylic acid, forms a hydroperoxide
which was detected in neutral solution. The stability of the hydroperoxides of cytosine, thymine, and their nucleotides was found to
be a function...
According to the World Health Organization’s (WHO) Tuberculosis Annual Report of 2014, from the 9 million cases worldwide, China has about 11% of these cases. Although the control of TB has improved over the years, China still has the second leading highest Tuberculosis epidemic in the world. Using literature reviews...
Experiments were conducted to determine the effect of environment
and several plant growth regulators on the physiology, quality,
and agronomic performance of snap beans (Phaseolus vulgaris L. )
and spring wheat (Triticum aestivum L. ). The potassium salts of
naphthenic acid and cyclohexanecarboxylic acid, received particular
attention.
Application of potassium...
Fire suppression has significantly increased canopy cover, litter depth, and stem density in many
western forests, altering microsite conditions that affect tree seedling establishment. We conducted studies in a
mixed-conifer forest in the Sierra Nevada, California, to determine relationships between established understory
trees and microsite quality, and to examine the...
Mortality patterns in an old-growth, mixed-conifer forest, in the absence of wildfire, were investigated at the Teakettle Experimental Forest from 2000 to 2002. We tested the hypothesis that after a century of fire suppression, pathogen- and insect-associated mortality (between episodic droughts) would be significantly greater on ingrowth trees (i.e., smaller-diameter,...
Mortality patterns in an old-growth, mixed-conifer forest, in the absence of wildfire, were investigated at the Teakettle Experimental Forest from 2000 to 2002. We tested the hypothesis that after a century of fire suppression, pathogen- and insect-associated mortality (between episodic droughts) would be significantly greater on ingrowth trees (i.e., smaller-diameter,...
The influence of fire and climate events on age structure of different species was examined in
old-growth mixed conifer in the southern Sierra Nevada. Within a 48-ha stem-mapped sample area, after a
mechanical thinning, all stumps were examined for fire scars and 526 stumps were cut to ground level and...
Sierra Nevada forests have high understory species richness yet we do not know which site factors influence
herb and shrub distribution or abundance. We examined the understory of an old-growth mixed-conifer
Sierran forest and its distribution in relation to microsite conditions. The forest has high species richness
(98 species sampled),...
Like much of the western United States, California’s forest has been severely altered by a century of fire suppression. The Sierra Nevada’s largest forest type, mixed conifer, which is primary habitat for more vertebrate species than any other Californian forest community, historically burned every 12–17 years. In 1894, John Muir...
The purpose of this study was to better understand the perceptions of employers and graduates regarding the applied baccalaureate degree when conferred by community colleges. By better understanding the perceptions of employers and graduates, community colleges considering offering applied baccalaureate degrees will have some context within which to begin communicating...
Blackside dace, Rhinichthys osculus nubilus (GIRARD), were
collected from ten western Oregon streams and examined for variation
among morphological and meristic characters. Several characters were
observed to vary between populations studied. Number of vertebrae,
number of scales in and above the lateral line, length of snout, and
depth of body...
Micro- and nanotechnologies are promising advancements across many industrial sectors, including alternative energy, chemical processing, and healthcare. In particular, a focus of research has been in manufacturing process development aimed at microdevice cost reduction and quality improvement. Microdevices take advantage of enhanced heat and mass transfer to improve energy and...
The decay scheme of Mn⁵¹ has been investigated using gamma-ray
and beta-ray scintillation spectrometers and a fast coincidence
spectrometer. A half-life value of 46.5 ± 0.2 minutes was determined
for Mn⁵¹ which decays predominantly to the ground state of
Cr⁵¹ by the emission of positons with an experimentally measured
end-point...
The hyporheic zone is of great interest for stream ecologists because of its role in stream biogeochemical processing. Our study addresses the effects of leaf-litter inputs and varying discharge on surface–hyporheic water exchange and their possible consequences for the hyporheic zone biogeochemistry. Our study was conducted during autumn in Riera...
One assisted reproductive tool used to propagate highly desirable genetics from elite sire and dam matings is embryo transfer. Superovulation is the first part of the overall protocol and it is a required yet costly and biologically stressful procedure in cattle embryo transfer. The process of superovulation results in high...
To understand the roles of forest management
practices in meeting the goals of forest sustainability and CO2
sequestration, we evaluated the effects of burning and thinning
treatments on soil respiration and soil environments in an
old-growth, mixed-conifer forest in California’s southern Sierra
Nevada. Six experimental treatments with two levels of...
Little is known about biophysical controls on soil respiration in California’s Sierra Nevada oldgrowth, mixed-conifer forests. Using portable and automated soil respiration sampling units, we measured soil respiration rate (SRR) in three dominant patch types: closed canopy (CC), ceanothus-dominated patches (CECO), and open canopy (OC). SRR varied significantly among the...
The purpose of this study was to estimate the portion of an ectomycorrhizal (ECM) fungi root
community with a hypogeous fruiting habit. We used molecular methods (DNA sequence analysis of the
internally transcribed spacer [ITS] region of rDNA) to compare three viewpoints: ECM fungi on the roots in a
southern...
The sedimentary, metamorphic, and igneous rocks of the
Callahan, California area formed on, or adjacent to, a Lower Paleozoic
island arc complex which has since been tectonically disrupted.
Sandstone, shale, lithic wacke, chert, banded quartzite, siliceous
mudstone, conglomerate, and limestone of the eastern Klamath belt
were deposited from the Middle...
Full Text:
north as Yreka. Zdanowicz (1971, p. 48), Porter (1973, p. 11),
Romey (1962, p. 19), and Potter (1977
The sedimentary, metamorphic, and igneous rocks of the
Callahan, California area formed on, or adjacent to, a Lower Paleozoic
island arc complex which has since been tectonically disrupted.
Sandstone, shale, lithic wacke, chert, banded quartzite, siliceous
mudstone, conglomerate, and limestone of the eastern Klamath belt
were deposited from the Middle...
The sedimentary, metamorphic, and igneous rocks of the
Callahan, California area formed on, or adjacent to, a Lower Paleozoic
island arc complex which has since been tectonically disrupted.
Sandstone, shale, lithic wacke, chert, banded quartzite, siliceous
mudstone, conglomerate, and limestone of the eastern Klamath belt
were deposited from the Middle...
The sedimentary, metamorphic, and igneous rocks of the
Callahan, California area formed on, or adjacent to, a Lower Paleozoic
island arc complex which has since been tectonically disrupted.
Sandstone, shale, lithic wacke, chert, banded quartzite, siliceous
mudstone, conglomerate, and limestone of the eastern Klamath belt
were deposited from the Middle...
A sucrose density-gradient ultracentrifugation technique for
obtaining microsomes has been developed. This technique has
advantages over the classic differential centrifugation technique, in
that it is faster, is better suited to work with small quantities of
tissue, and offers the opportunity to work with a defined microsomal
sub-cellular fraction, rather than...
This study was undertaken to determine the sorts of polygalacturonases
present in the culture filtrate of Fusarium oxysporum
f. sp. lycopersici, to purify and characterize these enzymes, and to
study any complexes that may form between polygalacturonase and
carbohydrate not degraded by the enzyme.
The polygalacturonase in culture filtrate consists...
This investigation was undertaken to determine 1) the effects
of various carbon sources in defined media on pectolytic enzyme production,
2) the effect of the incubation period on pectolytic enzyme
activity, and 3) the development of improved methods for the purification
and characterization of the polygalacturonases (PG) produced
by Fusarium...
An assay for fungicidal activity of sodium N-methyldithiocarbamate
(Na-MDC) and its decomposition products was developed
in which there was a minimum influence due to the widely varying
physical properties of the compounds (i.e. vapor pressure and water
solubility). Decomposition of the toxicant during the tests was
measured and held to...
The fungitoxicity of acetone extracts from the xylem of Fusarium
wilt disease resistant tomato plants (cv. Jefferson) inoculated with Fusarium
oxysporum f. sp. lycopersici was greatly influenced by environmental
factors. Extracts obtained from plants 1 h after watering were 4-times
more toxic than extracts from plants subjected to water stress...
The demand for new fungicides to control plant diseases has
led to experimentation with both previously used and newly developed
fungicides. Silver, an older but little used fungicide, was selected for
evaluation because of its high toxicity to microorganisms. Silver
nitrate and a silver electrolytic cell were tested as potential...
Bioassays of acetone extracts from xylem tissue in tomato stems
and corresponding reductions in Fusarium oxysporum f.sp. lycopersici
race 1 or 2 populations within the stems suggest that fungitoxic
materials within the xylem vessels of Bonny Best, Jefferson, and Marglobe
tomato cultivars initially kill a portion of the inoculum conidia....
With fire suppression, many western forests are expected to have fewer gaps
and higher stem density of shade-tolerant species as light competition becomes a more
significant influence on stand pattern and composition. We compared species composition,
structure, spatial pattern, and environmental factors such as light and soil moisture between
two...
The effects of management on soil carbon efflux in different ecosystems are still largely unknown yet crucial to both our understanding and management of global carbon flux. To compare the effects of common forest management practices on soil carbon cycling, we measured soil respiration rate (SRR) in a mixed-conifer and...
2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a potent immunosuppressant and a prototypic ligand for the aryl hydrocarbon receptor (AhR). In a graft versus host (GvH) response, treatment with TCDD suppresses a cytotoxic T-lymphocyte (CTL) response by Day 10, concurrent with a T-regulatory (Treg) like phenotype in the donor CD4+ T-cells, observed on Day...
Aquatic animals are exposed to a variety of natural and
anthropogenic xenobiotics. Biotransformation of xenobiotics was
examined in three aquatic animals: a primitive mollusc (chiton);
a shellfish which is an important human food source (oyster);
and, a lower vertebrate model for toxicological studies (rainbow
trout). Since digestive glands of Cryntochiton...
Landsliding is a significant contributor to continuous erosion
of the 150-mile northern Oregon coast. Direct loss of land to the sea
by landslides occurs along 47 percent of the coast. The remaining 53
percent has minor shifting of sand along depositional areas such as
spits and dunes. These minor movements...
There were two studies involved in the thesis research. In the
first study, variation in the amount of adenohypophysis gonadotropins
among 22 individual beef bulls were investigated. These bulls
represented four inbred lines, and six linecrosses. The bulls were
raised in the Oregon State University purebred herd.
The bulls were...
The scientific method applies hypothesis testing to material samples through experimentation, measurement, and data analysis, which produce representations—or features—that describe phenomena of interest. Biomolecular features come in numerous forms such as values, matrices, graphs, three-dimensional structures, trajectories, and molecular surfaces. Researchers have tested thousands of features related to protein molecules...
Rift Valley fever (RVF) is a mosquito-borne zoonotic viral disease native to the African continent. Outbreaks tend to occur in the wet seasons, and can affect numerous mammalian species including African buffalo. It is debated how the virus survives the inter-epidemic period when it is not detected in mammalian populations,...
With continual and worldwide human population growth, our impact on the natural environment expands and intensifies every day. We consume natural resources, burn fossil fuels, and release toxic compounds into the air, water, and earth. We build roads that fragment the landscape, construct new settlements, and develop agricultural lands in...
Raspberries are an important commodity worldwide, with the United States (U.S.) leading fourth in global production in 2017. An important factor when shipping propagated Rubus across the globe is the security of clean plant material verified through pathogen detection methods which is vital in preventing disease spread. A raspberry virus...
Using a linear quasi-geostrophic model of large scale spiraling flow and vertical density gradient in the eastern North Pacific, we evaluate the complex dispersion relationships for quasi-geostrophic waves. Our calculations indicate that the geostrophic circulation of the eastern North Pacific can locally convert potential energy to mesoscale kinetic energy on...
Three experiments compared ruminal, physiological, and performance responses of beef steers consuming hay ad libitum and receiving grain-based supplements with (CAM) or without (CO) inclusion of camelina meal. In Exp. 1, 9 steers fitted with ruminal cannulas received CAM (2.04 kg of DM/d) or CO (2.20 kg of DM/d). Steers...
To evaluate the immunologic and metabolic effects of OmniGen-AF® (Phibro Animal Health corporation, Quincy, IL; OG) supplementation in growing beef cattle, we designed three studies using replacement beef heifers (8.5 and 10.5 months of age) and steers supplemented across backgrounding, transition, and finishing periods. In Study 1, the effect of...
South Pacific intraplate volcanoes have been active since the Early Cretaceous. Their HIMU-EMI-EMII mantle sources can be traced back into the West Pacific Seamount Province (WPSP) using plate tectonic reconstructions, implying that these distinctive components are enduring features within the Earth's mantle for, at least, the last 120 Myr. These...
Some kinetics of the oxygen requirement of amine oxidases
have been investigated using bovine plasma monoamine oxidase (PAO)
and pea seedling diamine oxidase (DAO). A system is described for
studying enzyme reactions under controlled oxygen tension and in an
O₂-free N₂ atmosphere.
O₂ Km values were determined at two different...
The aryl hydrocarbon receptor (AhR) has recently been described as a novel therapeutic target, given the potent suppression of multiple immune-mediated diseases following activation by the prototypic ligand, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). In the parent-into-F1 graft-versus-host (GVH) model, suppression of the cytotoxic T-lymphocyte (CTL) response is associated with the presence of CD25⁺CTLA-4⁺IL-10⁺Foxp3[superscript...
During 1961, a program of shore station sampling of ocean temperatures
and salinities was carried out by the. Oceanography Department of Oregon
State University. This is a continuation of the work reported by
Kujala and Wyatt (1961). Sampling was conducted at 11 locations along
the Oregon coast and at one...
Emerging infectious diseases are increasing globally and are a threat to human, wildlife, and ecosystem health. The emerging fungal pathogen, Batrachochytrium dendrobatidis (Bd), or amphibian chytrid fungus, is associated with worldwide amphibian population declines and extinctions. Bd has been found on every continent where amphibians exist and has been documented...
Cell-based biosensors are function-based detectors that use the physiological response of a living cell to sense biologically stimulating agents. This emerging technology extends the application of current detection methods by reporting on the toxicity of a sample and the potential to cause disease. Previously, Betta splendens erythrophores have been described...
Cyprinid herpesvirus 3 (CyHV-3), commonly known as koi herpesvirus (KHV), is a member of the Alloherpesviridae and is a deadly pathogen for koi and common carp, Cyprinus carpio. It causes severe gill necrosis and nephritis, dermal ulceration and hemorrhage, and mass mortality of up to 100% of affected fish. Fish...
Vibrio parahaemolyticus is a Gram-negative, halophilic, human pathogenic bacterium ubiquitous in the marine environment. Like many Vibrio species, V. parahaemolyticus commonly associates with shellfish, particularly oysters. Ingestion of a raw or under cooked oysters contaminated with V. parahaemolyticus can cause gastroenteritis, which is typically self-limiting and rarely causes death. Globally,...