Cells are constantly bombarded with mutagens, both endogenous and exogenous in origin. Endogenous sources of mutation include reactive oxygen species formed during aerobic respiration, replication errors by DNA polymerase, and spontaneous deamination and depurination (Jackson 2009). Exogenous sources of mutation include UV and ionizing radiation, aflatoxins, and polycyclic aromatic hydrocarbons...
Genomic instability underlies diseases of unregulated cell growth that result in
cancers and developmental abnormalities in humans. Similar genome destabilizing
mechanisms are used to create genetic variety in crops for use in breeding and trait
development. Errors that occur during DNA replication may cause mutations if
they are not corrected...
Mismatch repair is one of the mechanisms by which cells ensure genomic
stability. Deficiencies in mismatch repair (MMR) increase mutation rates and cancer
risks. In the well-characterized methyl-directed Escherichia co/i system, MMR is
initiated by MutS, Mut L, and MutH proteins. The single MutS protein and the
single MutL protein...
Maintaining genome integrity is essential for an organism, as mutation
accumulation can lead to cancer, reduced fitness, and heritable diseases in offspring.
Therefore the study of mutations, how they are induced, and how they are prevented is
vital. Biomonitor systems are useful for understanding the relevant biological effects
of a...
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JohnB. Hays
Maintaining genome integrity is essential for an organism, as mutation
A unique, permanent root-growth arrest phenotype was observed in UV-B irradiated Arabidopsis thaliana roots lacking the DNA damage response kinase ATR. Segregation analysis suggests the dependence of this phenotype on another, unidentified gene, termed ursu. High-throughput sequencing technologies were used to map and identify the causal ursu mutation. Illumina HiSeq...
The highly conserved multi-protein mismatch repair (MMR) system is known for its ability to correct post replication errors in genomic DNA. A hallmark of MMR deficiency in all organisms is microsatellite instability. The initiating proteins in the eukaryotic MMR system are hetrodimers formed with an integral MSH2 subunit and one...
Genetic and environmental factors influence individual cancer risk. Mutations in DNA mismatch repair (MMR) genes increase colon cancer risk. Exposure to carcinogens, including the ubiquitous polycyclic aromatic hydrocarbons (PAHs), also is associated with increased cancer risk. To understand the combined effects of both environmental exposures and genetic risk, we investigated...
DNA mismatch repair (MMR) plays an important role in preserving genomic stability and reducing cancer risk. Environmental exposures to polycyclic aromatic hydrocarbons (PAHs) are believed to contribute significantly to carcinogenesis. PAHs are found in food, air, water and soil and upon bioactivation can form diol epoxides which are electrophilic in...
DNA mismatch repair (MMR) plays an important role in preserving genomic stability and reducing cancer risk. Environmental exposures to polycyclic aromatic hydrocarbons (PAHs) are believed to contribute significantly to carcinogenesis. PAHs are found in food, air, water and soil and upon bioactivation can form diol epoxides which are electrophilic in...
The DNA mismatch repair (MMR) pathway maintains genomic stability and
reduces cancer risk (colorectal and other internal cancers) by correcting polymerase
errors and activating cell cycle checkpoints and apoptosis in response to DNA damage.
Few studies have examined the influence of commonly encountered environmental
mutagens/carcinogens on the etiology of MMR-deficient...
The Oregon Department of Energy has set up recommendations for agricultural crop and non-crop embargo zones following an accidental or purposeful radioactive release. Of special interest are the FDA’s Derived Intervention Levels (DIL) and the state’s exposure limit of 0.4µR/hr. At the Oregon State University Emergency Response Research and Support...
The relationships between zinc, iron, and phosphorus in sweet
corn were investigated under field and greenhouse conditions. The
soils used in this study (both acid and calcareous) were low in available
zinc and phosphorus.
The experiments received standard, uniform rates of nitrogen
potassium, magnesium, and sulphur. Corn was used as...
NCRP report No.160 states that medical exposure increased to nearly half of the total radiation exposure of the U.S. population from all sources in 2006 (NCRP 2009). Part of this increase in exposure is due to the rise in nuclear medicine procedures. With this observed growth in medical radionuclide usage,...
I studied nest-site characteristics and habitat relationships for three species ofprimary cavity-nesting birds--hairy woodpecker (Picoides villosus), northern flicker (Colaptes auratus), and red-breasted sapsucker (Sphyrapicus ruber)-- over spatially heterogeneous landscapes in managed forests of the Southern Oregon Cascades during 1995 and 1996. The study was conducted on the Diamond Lake Ranger...
This study investigated the level of available resources, the
use of available resources, and the degree of planning and personal
perception of the situation of four female heads of households under
60 years old and four households with male heads over 65 years old.
The study was conducted in the...
Letters included were sent to request increased funding for the Titles I and II of the Tribally Controlled College or University Assistance Act. Another letter to the director of Indian Health Services expresses concern over funding delays to the tribes for diabetes.
The multistage model of carcinogenesis states that an accumulation of mutations in genes that are important for maintaining cellular homeostasis may lead to cancer. A specific type of mutation observed in particular types of cancer is the CC-->TT mutation found in the TP53 gene of patients with basal or squamous...
The aim of this study was to gain more information about the
interactions between DNA and the histone octamer during the
process of transcription. This work used a pUC8 plasmid derivative
that contained the core promoter region of the RNA polymerase I of
Acanthamoeba castellanii, placed upstream of four repeats...
Mitotic recombination is a common autosomal mutation in mammalian cells involving crossover events between homologous chromosomes. This process can convert a cell with a heterozygous deficiency to one with a homozygous deficiency, and thus often represents the second step in tumor suppressor gene inactivation. In this study I examined the...
Four-stranded DNA junctions (also known as Holliday junctions) are structural intermediates involved in a growing number of biological processes including DNA repair, genetic recombination, and viral integration. Although previous studies have focused on understanding the conformational variability and sequence-dependent formation of Holliday junctions in solution there have been relatively few...
Aquifer recharge is generally driven by fluids that move from the Earth’s surface to groundwater through the unsaturated zone, also known as the vadose zone. When the vadose zone is fractured, fluids, which may include contaminants, can move through the fracture network as well as the porous matrix. Such a...
John Wesley Powell worked actively for public land system
reform while a director of geographical and geological surveys in
the West from 1869 to 1894. Although this has won him acclaim as a
conservationist, the basis of Powell's linkage of reform with
scientific work is poorly understood.
A study of...
Published November 1952. 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
Currently little is known about the mechanisms and locations of
lymphocyte development in teleosts. In this study several aspects of the
underlying factors which govern B lymphocyte development in trout
were investigated which included: the isolation and characterization of
immunoglobulin heavy chain (IgH) genes, the recombination activating
genes 1 and...
Published August 1948. 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
The dynein molecule is a peculiar motor protein recognized for its unique stepping behavior. Sometimes it steps forwards. Other times it steps backwards. It has even been observed to occasionally shuffle by beginning a step with the same domain many times in row. These motions make dynein an interesting object...
Modern science was produced by a Christian society,
and although science has had an effect on Christianity, it
could not itself remain unaffected. In the second half of
the nineteenth century, the subject of evolution was as
much a religious as a scientific issue. The battle line
was drawn and...
This thesis is a work of literary non-fiction. It
is divided into six sections. The first, "A Sense of
Place," and the last, "Pulling a Geographical," are
collage essays which establish and then reiterate major
themes in the work: movement, work, geography,
climate, people, and education--some curricular, some
not. The...
Partial migration is a common migratory behavior where some individuals in a population migrate and others do not. Patterns of partial migration can vary dramatically, especially for species that inhabit a wide range of environments. I described and predicted spatial variation in marine migration (anadromy) of female Oncorhynchus mykiss (steelhead...
Forms/3 is a declarative visual programming language that aims to provide general purpose programming language capabilities in a simple, form-based approach. This report provides an example-driven introduction to programming in Forms/3.
There were two viable theories of generation, preformation
and epigenesis, existing in the Seventeenth and
Eighteenth Centuries. Due to their irreconcilable nature,
they were often at loggerheads during this time interval.
The status of these generation theories can be effectively
understood in terms of Thomas Kuhn's conception of preparadigm
science....
In education today, there is a growing sense of urgency to build the capacity of
educators, parents, and community members to work together to solve the complex issues
facing schools. The central purpose of this study was to explore how one elementary school
site council learned and adopted a set...
Major (Fe, Mn, Al) and minor (Cr, Mo, Pb, Zn, Cd) element
analyses of metalliferous sediments in cores from the East Pacific
Rise and Bauer Deep indicate that the Bauer Deep sediments are
similar in chemistry and origin to metalliferous sediments of the
East Pacific Rises.
Fe, Pb, and Zn...
Chronic hepatitis B disproportionately affects Asian Americans. Although Asians make up only 4.2% of the total United States (U.S.) population, they account for more than half of those infected with hepatitis B. If left untreated, chronic hepatitis B could lead to cirrhosis, liver damage, and liver cancer. Studies show that...
The research presented in this thesis was designed to evaluate
the effects of feeding alfalfa hays from the Klamath Basin of Oregon
in practical dairy rations on milk fat production in high-producing
Holstein cows. Thirty-two second lactation or older animals estimated
to be capable of producing at least 70 lbs...
Anthropogenic releases of trace gases into the
atmosphere are causing a decrease in stratospheric ozone
concentrations and a subsequent increase in solar
ultraviolet-B (UV-B)(280-320 nm) radiation reaching the
earth's surface. The objective of this study was to
determine the acute effects of enhanced UV-B radiation on
the primary production of...
A crucial factor in determining the accuracy of DNA replication is
maintenance of a balanced supply of deoxyribonucleoside triphosphates
(dNTPs) at replication forks. Perturbation of dNTP biosynthesis can
induce dNTP pool imbalance with deleterious genetic consequences,
including increased mutagenesis, recombination, chromosomal
abnormalities and cell death. Using the T4 bacteriophage system,...
This dissertation has two objectives. The first objective is to determine where best to situate the study of mentoring (i.e. the 'making of scientists') on the landscape of the history of science and science studies. This task is accomplished by establishing mentoring studies as a link between the robust body...
The Columbia River system in the Pacific Northwest is currently comprised of a series of
reservoirs, resulting from regulation of river flow due to a series of hydroelectric dams.
A return to pre-dam conditions might improve salmon (Oncorhynchus sp.) survival rates
and increase migration efficiency. This study modeled both historic...
In Culture and Imperialism, Said illustrates that we have no "autonomous cultural forms," but rather "impure" ones that are the products of historically "discrepant experiences." American culture has an interesting relationship with the history of imperialism. The Europeans that settled the U.S. imported slave labor to assist in the growth...
Global increases in ultraviolet-B radiation (UVBR:290-
320 nm) resulting from decreases in stratospheric ozone
concentration have the potential to alter marine primary
production and affect global climate and marine trophic
dynamics. Effects of UVBR on phytoplankton carbon fixation
were determined from open ocean exposure studies conducted
off the coast of...
Studies were conducted under controlled conditions in order
to observe the resulting survival patterns in solid crabmeat of
Salmonella typhosa, Salmonella paratyphi B, and SaImonella wichita
following individual exposure to various doses of gamma radiation.
As shown in their survival curves, these species of Salmonella
exhibited in varying degrees a...
Two experiments were conducted to determine the effects of daily (D) vs
alternate day (AD) supplementation of soybean meal (SBM) or wheat
middlings (WM) on forage organic matter intake (OMI), ruminal digesta
kinetics, total tract digestibility, and ADG of steers consuming low quality
forage. In Exp. 1, five Angus x...
Clear Creek, tributary of North Fork John Day River, is a mountain stream located in the Blue Mountains of eastern Oregon. It joins Granite Creek about 1.5 miles below the old abandoned mining town of Granite. Gravel removed from Clear Creek by gold dredging activity was replaced in a 3.37-mile...
In 2008 the U.S. Geological Survey began a Global Change study that evaluated the watershed scale response to climate change in selected basins across the United States. Fourteen basins for which the Precipitation Runoff Modeling System (PRMS) had been calibrated and evaluated were selected as study sites. PRMS is a...
Questionnaires were mailed to farmers in six counties of the
Willamette Valley requesting the kind and size of enterprises and the
gross income received from the enterprises on each farm.
Enterprises were defined both as general livestock or crop categories
and as individual crop or livestock enterprises. Two computer
programs...
Global amphibian declines have been attributed to numerous and often synergistic causes, such as invasive species, pathogens, and ultraviolet-B (UV-B) radiation. The effects of these stressors are context dependent and can vary with location, species, and populations. As sensitivity to UV-B has shown inconsistencies across amphibian taxa, it can be...
Commercial hog diets in the United States commonly contain lipid sources high in polyunsaturated fatty acids, most notably linoleic acid (18:2). This may result in greater deposits of linoleic acid in pork adipose tissue, contributing to an increased potential for lipid oxidation, high n-6/n-3 fatty acid ratio and increased fat...
The Middle Fork John Day Basin in Northeastern Oregon is prime habitat for spring Chinook salmon and Steelhead trout. In 2008, a major tributary supporting rearing habitat, Big Boulder Creek, was restored to its historic mid-valley channel along a 1 km stretch of stream 800 m upstream of the mouth....
Endophytic fungi (A. coenophialum and A. lolii) which infect grasses produce ergot alkaloids that serve as the grasses' chemical defenses and enhance the vigor of the grass. Turf-type tall fescue with high endophyte levels has been deliberately developed to produce a greener, more vigorous, pest-resistant turf. Consumption of endophyte-infected grass...
Polyacrylamide gel disc electrophoresis of concentrated culture
media which had supported growth of Clostridium botulinum
types A and B was shown to be effective in separating the toxin
molecules from hemagglutinating molecules. Since the hemagglutinins
of the two types are immunologically identical and are present
in toxin and toxoid preparations,...
I examined two amphibian communities to assess factors
that may impact amphibian biodiversity. The results suggest
that the potential factors which influence the maintenance
of amphibian biodiversity are multi-faceted and thus,
attempts to understand these factors must reflect these
complexities.
I investigated factors that influenced the susceptibility
of western toad...
The Mahakam Delta which was once among the largest mangrove forests in Indonesia, has been subjected to dramatic changes in structure and function due to massive shifts from mangrove forest to shrimp ponds and oil and gas development. To understand the impacts of mangrove loss to the greenhouse gas (GHG)...
Because riparian canopy controls most energy inputs to stream
ecosystems, it directly affects the structure of aquatic food webs and the
ecological processes that govern interactions among trophic levels. This
study addresses the interdependence among riparian canopy, benthic
community structure, and the carrying capacity of high desert streams for
salmonid...
This study focuses in providing the knowledge on carbon (C) stocks, emission and ecosystem productivity related to land use/land cover change in tropical peatlands. The field research activities were conducted for about 17 months between August 2013 to December 2015, at Pematang Gadung peat dome (peat depth up to 10.5...
Major and trace element analyses were made on biogenic carbonate,
silica, and fish debris and on authigenic philhipsite, micronodules, and
yellow and brown aggregates recovered from Bauer and Roggeveen Basin
metalliferous sediments. Phase components and the bulk samples were
analyzed by INAA and MS methods. Leachates and residues from ammonium...
Mangrove forests store more organic carbon across ecosystem carbon pools than most other coastal and forested ecosystems, and are subject to high global rates of deforestation. For these reasons, they are recognized as prime candidates for inclusion in climate change mitigation strategies. However, the ecological drivers of regional and micro-scale...
The extensive and expanding use of radioactive materials
(RAM) in the production of power, industry, the healing
arts, and various branches of research has inevitably
resulted in a sizable increase of hazardous material
transportation in the state of Oregon. The location of the
Hanford facility just north of the Oregon...
The evolution and maintenance of multiple phenotypes within populations is an interesting evolutionary and ecological question, and is becoming increasingly important for the restoration and conservation of partially migratory species. In particular, why individuals adopt a particular phenotype has been the focus of numerous research efforts. In the partially migratory...
The need for increased efficiency in regeneration of western hemlock (Tsuga heterophylla (Raf.) Sarg.) requires greater understanding of seedling physiology. Experiments examined western hemlock seedling growth responses to in-bed root pruning, and pruning of shoots or roots prior to transplanting. Measurement of plant
moisture stress (PMS) after physical root disturbance,...
A growing realization that wetlands are potentially
valuable resources has recently stimulated efforts towards
their protection. While a foundation for wetland management
exists, decision makers still lack adequate tools for addressing
issues of wetland preservation vs. development.
Wetland preservation values are often neglected in traditional
market analyses and in the...
The mycorrhizal rootlets of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco.) and red alder (Alnus rubra Bong.) were extensively investigated. A jet-black mycorrhiza was found to be dominant on Douglas-fir rootlets. The fungal symbiont was identified as Cenococcum graniforme (Sow.) Ferd. and Winge. Two forms of mycorrhizae predominated on root systems of...