Revised August 1970. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Wheat endosperm morphogenesis was studied by light microscopy
during the entire growth period of anthesis to maturity. Four
developmental stages have been described in this thesis: (1) double
fertilization, (2) formation of the lower endosperm cells, (3)
termination of nuclear divisions, and (4) initiation of protein
bodies.
The first manuscript...
Marine bacterioplankton play an important role in global elemental cycles because they return carbon dioxide and nutrients to the biosphere as they reduce organic matter. Furthermore, marine bacterioplankton are not uniformly active, and subpopulations of the in situ community may be more or less active at any given time. Defining...
This research examines the downstream fining phenomenon as it operates in coastal gravel-bed rivers of Oregon. Downstream fining is a change in bed composition toward smaller sediment sizes in the downstream direction. Changes in stream flow discharge and channel slope affect the rate of bed-load transport, thereby altering the downstream...
Published June 1951. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Published November 1950. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Consistent with its charge under Oregon House Bill 3543, the Oregon Climate Change Research Institute (OCCRI) conducts a biennial assessment of the state of climate change science, including biological, physical, and social science, as it relates to Oregon and the likely effects of climate change on Oregon. This sixth Oregon...
Previous investigations of glacier dynamics at Tioga Pass during the Last Glacial Maximum (LGM) have produced different conclusions. A map of the LGM ice extent and flow direction (Alpha et al., 1987) illustrates a south-to-north direction of ice flow across the pass with little evidence to support this inference. Since...
Take-all root rot (Gaeumannomvces araminis var.tritici) is
a major disease of wheat (Triticum aestivum) in western Oregon.
Control of take-all is dependent on management practices such as crop
rotation and soil fertility-plant nutrition relationships. The
objective of this study was to develop a bioassay that could measure
the influences 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...
Use of Granier-style heat dissipation sensors to measure sap flow is common in plant physiology, ecology and hydrology. There has been concern that any change to the original Granier design invalidates the empirical relationship between sap flux density and the temperature difference between the probes. Here, we compared daily water...
This thesis includes three studies involving different aspects of modeling protein structure. The first study illustrates the levels of insight available from atomic-resolution protein structures. The second study derives general trends of protein geometry from atomic-resolution structures and shows their implications for modeling. The third study creates a model of...
Four root mutants, diageotropica (dgt), and altered root architecture (ara) 1, 2, and 3, were used to study root architecture and better understand the process by which root architecture is determined. Adventitious root formation, tissue response to auxin, nutritional response, and starch accumulation in the leaves were tested in ara...
Native shrublands and their associated grasses and forbs have been disappearing from the Great Basin as a result of grazing practices, exotic weed invasions, altered fire regimes, climate change and other human impacts. Native forb seed is needed to restore these areas. The irrigation requirements for maximum seed production of...
Ground-based assessments of foliar diseases including leaf blight are time-consuming and costly. We investigated the potential for using an unmanned aerial system (UAS) in conjunction with a multispectral sensor to determine whether we could more efficiently and reliably detect and quantify leaf blight in Pacific madrones. Our methods included ground-based...
Conflicts can arise when the recovery of one protected species limits the recovery of another through competition or predation. The recovery of many marine mammal populations on the west coast of the United States has been viewed as a success; however, within Puget Sound in Washington State, the increased abundance...
Swiss needle cast (SNC) is a foliage disease of Douglas-fir caused by Nothophaeocryptopus gaeumannii, an Ascomycete fungus (Mycosphaerellaceae) that causes growth reductions in Douglas-fir plantations across the Pacific Northwest. Epidemiology of the fungus is generally well known in plantation trees, but the relationship between disease expression and foliage nutrition and...
The upper ocean current and temperature fields in the western Weddell Sea were measured from the drifting pack ice at Ice Station Weddell 1 (ISW) and nearby sites using a vertical profiler and an array of moored sensors in January–June 1992. These data document the structure and variability of the...
Twelve stream segments in the Silvies River drainage system were classified in
the fall of 1993 and again in 1994, using a morphological classification of natural
rivers (Rosgen 1994). Bankfull flow of stream channels is the key feature of this
system. Measurement of bankfull is used in the calculation of...
The first goal of this study was to understand the role of u-calpain in skeletal muscle protein degradation in cultured muscle cells. Several strategies were developed to down-regulate endogenous u-calpain activity and m-calpain activity in rat myotubes. These included over-expression of antisense u-calpain (AnsL), dominant negative u-calpain (DN-u-CL), antisense 30K...
Agrobacterium rhizogenes has been shown to cause root
proliferation and increased water use efficiency in
certain woody dicots. Root proliferation may be desirable
in herbaceous legumes as a means of increasing potential
sites for infection by Rhizobium species and subsequent
nodulation and nitrogen fixation. Thus, A. rhizogenes was
used to...
The effects of enriching the rearing environment of laying hens on their learning ability and behavior were investigated. Day old ISA brown layer chicks were group housed in open floor pens that were either enriched or unenriched. The enriched rooms contained visual stimuli in the form of hanging decorations, auditory...
Chemical and biological sensor technologies have advanced rapidly in the past five years. Sensors that require low power and operate for multiple years are now available for oxygen, nitrate, and a variety of bio-optional properties that serve as proxies for important components of the carbon cycle (e.g., particulate organic carbon)....
Skeletal muscle is the largest organ in the body by mass, comprising roughly 40% of total bodyweight in adults. It plays diverse and unique roles that include movement, locomotion, and support for posture and internal organs, among others. The structural foundation for all skeletal muscle in adults is formed early...
The boundary between ice and basalt on Earth is an analog for some near-surface environments of Mars. We investigated neutrophilic iron-oxidizing microorganisms from the basalt-ice interface in a lava tube from the Oregon Cascades with perennial ice. One of the isolates (Pseudomonas sp. HerB) can use ferrous iron Fe(II) from...
Full Text:
, R., Rachel, R., Roßnagel, P.,
Burggraf, S., Huber, H., and Stetter, K.O. (1996) Ferroglobus
placidus
Microbial-induced corrosion of concrete (MICC) is a multi-stage deterioration process caused by microbial activity in wastewater infrastructure. MICC is a worldwide issue due to the reduced service life of the wastewater infrastructure and the economic impact associated with increased maintenance and reconstruction costs. This thesis explores two critical aspect of...
Despite the advances in surgery, physical therapy, and pharmaceutical agents, muscle
dysfunction (i.e., atrophy and weakness) continues to impair recovery from an anterior
cruciate ligament (ACL) injury and surgery. Ischemia-reperfusion injury during surgery
and the subsequent limb disuse are two events experienced by patients having ACL
surgery. Oxidative stress and...
Inflorescence necrosis (IN) is a recently described disorder in grapes
characterized by partial or complete deterioration of the pedicel and rachis near
bloom. Elevated levels of ammonium in the rachis are associated with the
incidence of IN and hypothesized as the cause of the disorder. An incubation
system with single-node...
Cell-to-cell communication by chemical signals, termed quorum sensing (QS), is a common regulatory scheme in the microbial world. Pseudomonas aeruginosa¸ an opportunistic pathogen of burn wounds and cystic fibrosis lungs, uses QS to control the expression of hundreds of genes, particularly those necessary for population level benefits such as biofilm...
Dense hyphal mats formed by ectomycorrhizal (EcM) fungi are prominent features in Douglas-fir (Pseudotsuga menziesii) forest soils and have been estimated to cover up to 40% of the forest floor in some stands. Although previous studies have examined various aspects of EcM fungi, little is known about their associated microbial...
Oomycetes are some of the most devastating pathogens, causing upwards of billions of dollars of damage each year to plants. They also diminish ecological diversity and health through the destruction of trees and shrubs. The genome sequence of Pseudoperonospora cubensis, an obligate plant pathogen and causative agent of downy mildew...
Accommodating motor vehicles that are turning (left or right) at signalized intersections requires a careful understanding of the safety and efficiency of design and operational variables. Turning vehicles are the primary collision risk for non-motorized road users at signalized intersections. When turning movements need to be controlled, proper driver response...
Greenhouse and field grown coffee plants were used to
study the synchronization of flowering and fruiting. The
purpose of these studies was to develop methods of
improving the selective harvesting of mature coffee fruits
by machine. The studies were divided into 4 parts: 1)
Synchronization of flowering, 2) Synchronization of...
Interception of precipitation by forest canopies has been found previously to reduce rainfall intensity, but this effect is poorly understood. The goal of this research is to quantify the attenuation of rainfall intensity by forest canopy interception, with the specific objective of estimating the contribution of this attenuation to hillslope...
The influence of fertilization on disease severity is unknown in most forest pathosystems. Fertilization treatments were randomly applied to 0.01 ha plots centered on individual dominant or co-dominant Douglas-fir trees in ten Douglas-fir stands from coastal Oregon to the foothills of the Oregon Cascade Range, USA. This region is affected...
Two trials were conducted to evaluate changes in the quantity, quality, and moisture of available forage in the pasture, and shrub utilization by cattle during a 30-d late summer grazing period (Trial 1) and the effect of cow age (experience) on grazing distribution and diet composition (Trial 2) in mountain...
Global environmental change is causing local extinctions of species. When species depend on one another, as in the mutualistic relationship between plants and pollinators, loss of one interaction partner may cause cascading effects within the community – such as additional extinctions and reduced pollination services. Network theory provides a way...
Estimating volume gains in genetically improved stands at rotation age is challenging because first-generation progeny tests in Douglas-fir were typically established to measure the relative growth performance of individual trees from open-pollinated parent trees. The overall goal of this dissertation research was to improve growth simulation of genetically improved Douglas-fir...
Recent advancements in unmanned aerial vehicle (drone*) technology, sensors, and software applications have increased efficiency in data collection, reduced human error, and increased safety while managing a wide range of projects. No longer relegated solely to military use, drones have become synonymous with picturesque views of natural wonders and resources...
Spalting fungi show strong potential as natural colorants on a variety of materials, specifically textiles and wood. Four species of spalting fungi are currently utilized in this manner: Scytalidium cuboideum, which produces a red pigment called draconin red, Scytalidium ganodermophthorum, that produces an unknown yellow pigment, and Chlorociboria aeruginosa and...
Forest harvest can have significant impacts on forest ecosystems that may influence the capacity of soils to sequester carbon (C). The microbial community controls decomposition, which is a critical process in partitioning litter- and root-C between CO₂ and storage in semi-permanent soil-C pools. The objectives of this study were to...
Intimate associations with reactive metal species permanently protect soil organic matter (SOM) from microbial access and oxidation, contributing to the build-up of organic carbon (C) stocks in soils. It is increasingly recognized, however, that such associations can be reversible and that reactive metal species might even facilitate the oxidation of...
This study was directed to improve our understanding of the ecology of Swiss needle cast (SNC) of Douglas-fir, a disease that produces extensive damage to forests and plantation in the coastal region of Oregon and Washington. A disease prediction model for the coastal area of Oregon was built by establishing...
The myxozoan Ceratonova shasta is an intestinal parasite of salmon and trout that causes ceratomyxosis, a disease characterized by severe inflammation of the intestine that can lead to hemorrhaging, necrosis, and death of the fish host. The parasite is endemic to the Pacific Northwest of the United States and Canada,...
"The First North American Root Weevil Workshop was held at the Oregon State University North Willamette Research and Extension Center in Aurora, Oregon, November 1–2, 2001. The participants discussed topics including root weevil biology, detection, and monitoring, as well as the population dynamics and integrated pest management of root weevils...