Severe infection by the endemic myxozoan parasite, Ceratonova (synonym, Ceratomyxa) shasta, has been associated with declines in and impaired recovery efforts of populations of fall-run Chinook Salmon Oncorhynchus tshawytscha in the Klamath River, California. The parasite has a complex life cycle involving a polychaete worm host as well as a...
The myxozoan parasite, Ceratomyxa shasta, is the most significant pathogen of juvenile Chinook salmon (Oncorhynchus tshawytscha) in the Klamath River, CA, USA. This parasite requires two hosts - a freshwater polychaete (Manayunkia speciosa) and a salmonid - to complete its life cycle. The complex life cycle and large geographic area...
Cyclopropenoid fatty acids (CPFA), which are a group of
fatty acids produced by plants of the order Malvales, are known
to induce adverse physiological effects when administered to a
variety of animal species. A structurally strained cyclopropene
ring is present in all CPFA and is believed responsible for the
toxic...
The myxozoan parasite Ceratomyxa shasta is a significant pathogen of juvenile salmonids in the Pacific Northwest of North America and is limiting recovery of Chinook (Oncorhynchus tshawytscha) and coho (O. kisutch) salmon populations in the Klamath River. We conducted a 5-year monitoring program that comprised concurrent sentinel fish exposures and...
Two experiments were conducted to examine the effect of
a cyclopropenoid fatty acid on luteal cell function. In Exp.
1, 12 mature ewes were mated to a fertile ram, assigned to two
groups (n = 6/group) and laparotomized on day 18 of gestation.
Ewes with corpora lutea (CL) in both...
In this five-week feeding study male New Zealand rabbits were
fed diets containing cyclopropene fatty acids (CPFA), diets containing
cholesterol, and diets with both CPFA and cholesterol added to test
the effect of CPFA on cholesterol metabolism and atherosclerosis
induction. When CPFA-fed animals were compared with control
animals, they tended...
Cyclopropenoid fatty acids (CPFA) are unique compounds that
contain a highly strained and reactive cyclopropene ring structure.
These compounds have been shown to cause a number of toxic effects
in a variety of animals. Rainbow trout (Salmo gairdneri) have
proven to be particularly sensitive to CPFA. Studies have revealed
that...
Three studies were conducted to determine the effects of
cyclopropenoid fatty acids (CPFA) on the membrane components of livers
of rainbow trout (Salmo gairdneri). In the first study, ¹⁴C-sterculic
acid was administered by intraperitoneal injection into rainbow trout
and the trout maintained for 72 hours. The labelled sterculic acid
was...
Ceratonova gasterostea n. gen. n. sp. is described from the intestine of freshwater Gasterosteus aculeatus L. from the Klamath River, California. Myxospores are arcuate, 22.4 +/- 2.6 μm thick, 5.2 +/- 0.4 μm long, posterior angle 45 +/- 24°, with 2 sub-spherical polar capsules, diameter 2.3 +/- 0.2 μm, which...
Corn oil (CO) and Sterculic foetida oil (SFO) fed rats were
injected with [9, 10-methylene-¹⁴C]sterculic acid. Less than 1%
of the label was expired as carbon dioxide. The majority of the
label was excreted in the urine as short-chain dicarboxylic acids with
an intact cyclopropane ring. The major metabolites for...
Cyclopropenoid fatty acids (CPFA) are natural components of
cottonseed oil, a major food oil in the United States. The ability of
CPFA to cause abnormal biochemical and physiological effects when
fed to laboratory and farm animals has prompted an investigation of
their effects on mice.
Between 0.05 and 0.55% CPFA...
Three studies were designed to evaluate the promoting
effect of cyclopropenoid fatty acids (CPFA) on avian myeloblastosis
virus (AMV) infection in White Leghorn chickens.
In the first study effects on growth parameters, blood serum
and erythrocyte lipid composition of White Leghorn chickens
were investigated at 100 ppm and 300 ppm...
The cyclopropene fatty acids, sterculic and malvalic, occur
naturally in a major food lipid, cottonseed oil, and have been implicated
in several physiological disorders. Rainbow trout in this
study were fed semipurified diets containing 200 or 300 ppm methyl
sterculate, and the effects on hepatic lipid and glycogen levels,
lipid...
Most parasites and their hosts live in a balance within their environment; however a disease outbreak can occur when either the parasite, host, or environment, are perturbed. Myxozoan parasites are associated with a wide variety of cultured and wild fish populations. Most myxozoans are relatively benign to their vertebrate host;...
The freshwater polychaete Manayunkia speciosa was identified as an obligate host of the salmonid parasite Ceratomyxa shasta in 1997, prompting increased research on the small benthic invertebrate. Ceratomyxa shasta infection in fish can cause mortality, and presents a disease risk for both hatchery and wild salmon and trout. Ceratomyxa shasta...
Cyclopropenoid fatty acids cause several physiological disorders
in rainbow trout and rats. Rainbow trout appear to be more sensitive
than rats to the effects of cyclopropenoid fatty acids. Carbon-14
labeled sterculic acid with label in the methylene position of the
cyclopropene ring was injected into the stomach of rats and...
"The Service is proposing to establish the Siletz Bay National Fish and Wildlife Refuge by initially accepting a donation of 46 acres of salt marsh, acquiring up to 793 acres of land, and cooperatively managing 1,060 acres of tidelands with the State of Oregon... The primary need for the Service...
The within-host interactions that can occur as a result of mixed infections in wildlife likely influence the outcome of an infection. We investigated the infection frequency and outcome as well as the potential mechanisms regulating mixed infections with two Ceratonova shasta genotypes within the Chinook salmon host. Previous research in...
Fifty-seven stranded marine mammals representing seven species
were examined over a period of three years. The primary cause of
death along with contributing factors, incidental pathology and
parasites is reported for each animal examined.
Gunshot wounds directly or indirectly caused the death of 14
of 44 seals and sea lions...
Dietary cyclopropenoid fatty acids (CPFA) have long
been known to cause pronounced physiological disorders in
both farm and laboratory animals. Past work has shown
CPFA to be a powerful promoter of carcinogenesis in trout,
rats and mice. Sterculic and malvalic acids (CPFA's) are
found in seed lipids of plants from...
Shortnose Sucker (Chasimistes brevirostris) and Lost River Sucker (Deltistes luxatus) are endemic to the Upper Klamath Basin of Southern Oregon and Northern California. Populations of these fishes have been dwindling since the 1960’s and both species where listed to as endangered in 1988. Poor recruitment is thought to be a...
The purpose of this study is to identify factors that support the likelihood of persistence of academically underprepared community college students to 45 college level credits. Factors considered in this research include: (a) race/ethnicity, (b) age, (c) enrollment status, (d) socio-economic status (SES), (e) first quarter GPA, (f) developmental need,...
Seven experiments were carried out to investigate the
involvement of carbohydrate and lipid metabolism on the
incidence of Sudden Death Syndrome (SDS) in broiler
chickens.
Hepatic arachidonate level decreased after 1 h postmortem.
The decreased level of hepatic arachidonate
previously observed in SDS birds was, therefore, associated
with the post-mortem...
Studies were conducted to determine the effects of cyclopropenoid
fatty acids (CPFA) on the microsomal membrane of livers of rainbow
trout (Salmo gairdneri). Slab and tube gel electrophoresis of
microsomes from trout fed a CPFA diet (CPFA-microsomes) for varying
time periods showed a decrease in the number of protein bands...
This ethnographic research aims to discover the implications of the
commodification of production processes amongst the Ersu Tibetans of Sichuan,
China. This thesis examines the commodification of Ersu agriculture and ethnic
identity in the historical context of both China and the world-system. Ethnohistorical
and ethnoecological methodologies are utilized to answer...
This study examines the spatial and temporal distribution and life history of the "offshore" component of the Northeastern Pacific spiny dogfish (Squalus acanthias) population. Distribution was examined in relation to latitude, depth, the Columbia River plume and large-scale climate changes. Fishery and survey data indicate that the Northeastern Pacific spiny...
Diseases caused by parasites are recognized as significant sources of mortality in wild fish populations. I assessed the impacts of multispecies parasitism on a threatened stock of juvenile coho salmon (Oncorhynchus kisutch). A crucial prerequisite to this research was proper identification of parasites, which can be difficult for species lacking...
The purpose of this study is to examine the learning that occurs in Latina students
who enroll in learning communities designed for underprepared community college
students. The research question guiding this study is: What are the experiences of Latina
students enrolled in developmental learning community courses which have the greatest...
Pre-spawning mortality (PSM) presents a major problem for population recovery of spring Chinook salmon (Oncorhynchus tshawytscha) in the Willamette River basin. In certain reaches and years, PSM has exceeded 90%. Histology has been used as the primary diagnostic method to investigate PSM in the Chinook Salmon, and a collection of...
It is difficult to treat the heartwood of many wood species with liquid preservatives using conventional liquid processes. Supercritical fluids (SCF) used as carriers of preservatives to impregnate refractory wood species may be an attractive alternative to conventional liquid carriers. While SCF impregnation has many potential advantages, some wood species...
The use of Native American fire regimes evolved in the Klamath-Siskiyou bioregion over millennia. A mixture of Native American and Euro-American socio-cultural management has developed from adaptations to climate, topography, ecological processes, and land use practices. This research incorporates Traditional Ecological Knowledge (TEK) to partially examine the role of tribal...