The approximation of a continuous function, in the maximum
norm, by continuous splines in the Everett Interpolation Form is considered.
The topics of characterization, uniqueness, and calculation
of best approximations are investigated. Since uniqueness fails, a
new vector-valued norm, which yields uniqueness, is introduced.
Studies to identify the environmental factors that influence the rate of ectotrophic mycelial growth of Phellinus weirii (Murr.) Gilbertson along Douglas-fir roots were undertaken both in the laboratory and in the field. The effects of soil pH, nitrogen, moisture, temperature, microorganisms and bulk density were investigated. In the lab, the...
Phellinus weirii (Murr.) Gilbertson, cause of laminated
root and butt rot, is a heterothallic basidiomycete lacking
clamp connections. Two biological species groups of the fungus
have been hypothesized, the Douglas-fir and cedar-types, on the
basis of physiological, morphological and epidemiological
differences. Single-spore and vegetative isolates differ in
cultural morphology, nuclear...
Colonization of N. densiflorus tissues by P. ramorum is not well understood. The pathogen is able to colonize nearly all tissues of this host but it is unclear how a tree is ultimately killed. Because this is such a destructive invasive pathogen, it is important to investigate its pathogenic strategy....
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Everett M. Hansen
Colonization of N. densiflorus tissues by P. ramorum is not well
Two land breeze events occurred off the Oregon coast on the
nights of April 19th and 20th, 1973. An array of four moored toroid
buoys and one land station recorded the effect of the land breeze event
on the surface mesoscale wind and temperature fields. The land
breezes may have...
The one-dimensional numerical model developed by Carl R.
Goodwin is applied to the Siuslaw estuary. Vertical displacement,
horizontal velocity and flow of the water as a function of time and
distance from the mouth given by the model are compared with field
observations taken under different water mixing conditions in...
Fourier techniques have recently become popular for the
description of underwater image transmission. Two properties
necessary for the application of Fourier techniques to any system
are those of linearity and invariance. This work describes a
laboratory investigation of these properties for a variety of
aqueous media. The hypothesis is found...
The climate and the exchange of heat between atmosphere and
ocean are examined in a region adjacent to Washington and Oregon,
and in two sub-regions adjacent to Oregon. The sub-regions are
chosen such that one contains the nearshore upwelling region and the
other borders it on the seaward side.
The...
The wind field measured during Project JASIN 1972, a joint
British-American venture during September 1972, was analyzed.
These measurements were done, with equipment manufactured by
Ivar Aanderaa of Bergen, Norway, on large, anchored toroid buoys.
The results of the analysis of the wind field, which included
divergence and vorticity estimates...
The primary objective of this research was to determine if native species within the genera Castilleja and Pedicularis are naturally infected by white pine blister rust (Cronartium ribicola) in whitebark pine ecosystems of the Oregon and Washington Cascade Range. Secondary objectives were to monitor the phenology of aecial and telial...
The root systems of Douglas-fir trees infected with
Verticicladiella wagenerii and assigned by crown color and terminal
growth characteristics to several stages of decline were excavated at
three widely separated sites in the Coast Range of Oregon. Data were
gathered on insect species present, extent of colonization of the root...
Described as one of the most destructive pathogens of agricultural crops and forest trees, Phytophthora is a genus of microorganisms containing over 100 known species. Phytophthora alni has caused collar and root disease in alders throughout Europe and a form of the species has recently been isolated in North America....
The phytopathogen Phytophthora ramorum (Werres, DeCock & Man in't Veld), causal agent of Sudden Oak Death (SOD) of oaks (Quercus spp.) and tanoaks (Notholithocarpus densiflorus syn. Lithocarpus densiflorus), is established in coastal forests of the western United States. Since the discovery of SOD in the Douglas-fir / tanoak forests of...
Phaeocryptopus gaeumannii is a pathogenic fungus on Douglas-fir needles which has become a serious threat to timber production in the last decade along the Oregon coast This research was undertaken to describe the general biology and pathology of F. gaeumannii on Douglas-fir needles and how environmental variables affect fungal development....
This exploratory study examined whether temperament, home environment, and family stress impact the amount of prosocial behavior displayed by pre-school age low-income children and examined how much of an impact each factor has. Each factor was explored in depth along sub-scale dimensions including, (1) self-regulatory temperament, negative reactive temperament, and...
To determine which isolates will most rapidly replace
Phellinus weirii in stumps and roots, Trichoderma spp. were
isolated from P. weirii-infested stumps and roots, identified, and
examined for growth rates and lethal effects on P. weirii in vitro.
Phellinus weirii-infested Douglas-fir stumps and stump roots
were sampled for microorganisms by...
The chlamydospore is a survival spore produced by 35 of the 75 described species of Phytophthora. Phytophthora ramorum Werres, de Cock & Man in't Veld, the causal agent of Sudden Oak Death (SOD), produces abundant chlamydospores in artificial culture and plant tissue. The chlamydospore is likely the most important survival...
In early 2000, unusual mortality of a native North American tree, golden chinquapin, was reported by the USDA-Forest Service. Dying trees exhibited girdling cankers in the inner bark of the lower bole, branch flagging and defoliation. Isolations from necrotic tissues and soil associated with diseased or killed trees yielded Phytophthora...
Groups of second-growth Douglas-fir (Mirb.) Franco were excavated
in plots of two to six trees on two sites in the vicinity of Cowichan
Lake, Vancouver Is., British Columbia. Eleven excavation plots provided
36 trees which could be studied in pairs (a total of 50 pairs) in order
to ascertain the...
Laminated root rot of Douglas-fir (Pseudotsuga menziesii (Mirb.)
Franco) caused by the fungus Phellinus weirii (Murr.)Gilbertson was
studied in two successive stands in the Oregon Coast Range. Damage
due to the disease in a 60-year-old second-growth stand was compared
with incidence in the preceding 300-year-old stand on the same site....
Port-Orford-cedar (Chamaecyparis lawsoniana) is a forest tree native to
a small area of Oregon and California. A root disease caused by
Phytophthora lateralis causes widespread mortality of Port-Orford-cedar.
This dissertation examines three important elements of the Port-Orford-cedar
P. lateralis pathosystem related to breeding for disease resistance:
use of resistant rootstocks...
Breeding Port-Orford-cedar for resistance to Phytophthora lateralis, a causal agent of root disease, begins by screening, through artificial inoculation, phenotypically resistant trees selected from natural stands. The successful program selected tolerant or resistant POC parent trees for the purpose of disease management. Candidate resistant POCs were used in my dissertation...
A hierarchical series of studies, based mainly on molecular data, was conducted to elucidate the life history of the Douglas-fir Swiss needle cast pathogen Phaeocryptopus gaeumannii at macro- and micro-evolutionary scales. This information was then utilized to design and evaluate molecular diagnostic tools for use in studies on the epidemiology...
The genus Phytophthora contains some of the most destructive pathogens of forest trees, including the most destructive pathogen of alder in recent times, Phytophthora alni. Alder trees were reported to be suffering from canopy dieback in riparian ecosystems in western Oregon, which prompted a survey of alder health and monitoring...
The era of "customer satisfaction" brings students to colleges who are increasingly identifying themselves as customers. Competition among a growing number of institutions and learning organizations is sharpening the desire of institutions to deliver high quality service in order to attract and retain students. Some examples of interactions where service...
Alaska-cedar (Chamaecvparis nootkatensIs (D. Don) Spach) is a
valuable tree that is suffering from a serious decline and mortality of
unknown cause throughout southeast Alaska. Epidemiological and
pathological studies were initiated to determine if a pathogen is the
primary cause of this problem. By examining old aerial photographs and
by...
Verticicladiella wageneri Kendr. is a vascular wilt pathogen of
Douglas-fir in the Pacific Northwest, The disease is characterized by
black staining of colonized sapwood; crown symptoms are those typical
of a wilting syndrome. Histopathological studies revealed that the
pathogen is limited to the xylem but causes vascular dysfunction in
both...
In 1991 Pacific yew (Taxus brevifolia Nutt.) was reported as a new host for Phytophthora lateralis Tucker and Milbrath which is an aggressive root rot pathogen thought previously to be specific to Port-Orford-cedar. This study was designed to compare the pathogenicity of P. lateralis on the two hosts, and to...
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 root disease fungus Inonotus tomentosus, common in the old
growth boreal forests of British Columbia, poses a threat to the
health of second growth forests established on sites with a previous
history of root disease. Colonized stumps occur in groups of 1 to 6;
the groups are clumped within...
Phellinus arctostaphyli (Long) Niemela, P. igniarius
(L. ex Fr.) Quel., and P. tremulae (Bond.) Bond. et Boriss.,
heartrotting hymenomycetes in the family Hymenochaetaceae
(Aphyllophorales), all conform to a multi-allelic heterothallic
mating system. Both compatible and incompatible
reactions result from pairings of homokaryons from the same
basidiocarp. Homokaryons isolated from different...
Surveyor Deep-Sea Channel extends for approximately 700 km
over the northern Alaskan Abyssal Plain. It originates near the base
of the continental slope opposite Dry Bay and Alsek Strath and terminates
in the Aleutian Trench south of Kodiak Island. East of Giacomini
Seamount, the axial gradient of the channel is...
Understory species associations and their association with tree species were examined on three intensively studied stands. We studied the chronosequence of understory species associated with different aged singleleaf pinyon (Pinus monophylla Torr. and Frem.) trees. Mid- to late pinyon-juniper understory succession was found to be more spatial than floristic in...
The shallow, wave-swept sea floor off the central Oregon coast
is used by 0-age flatfishes as a nursery ground. This dissertation
is based on a series of projects designed to: 1) identify the dominant
meiobenthic nematodes present in a coastal nursery area; 2)
describe the important temporal and spatial scales...
Aquatic communities consisting of guppies, amphipods, copepods, snails, nematodes, rotifers, protozoans, euglenoid flagellates, and other microorganisms were established in sixteen laboratory microcosms. Guppies were exploited at four different levels (0 percent, 10 percent, 20 percent, and 40 percent of the population biomass) with four communities at each level of exploitation....
All carbon steel that is used in tools, springs,
and machine parts where tempering is necessary undergoes
three distinct heat treatments: first, heating for forging;
second, heating for hardening; and third, heating
for tempering.
This study was undertaken to determine the
effects of different chilling treatments during the dormant
season upon growth of Douglas-fir seedlings0 In
addition it was planned to determine whether seedlings
native to various geographic areas differ in their chilling
requirements0
The hypotheses were advanced, based on previous
studies, that chilling...
Sound waves are very convenient for the investigation of
all wave phenomena with the exception of polarization. They are
particularly useful in connection with microwaves because the
latter's wave length can be easily duplicated with sound waves,
making it possible to obtain the same diffraction pattern for
both when confronted...
This study was designed to evaluate the relative effectiveness
of a new college general biology course which utilized an audio -
tutorial laboratory as contrasted with a traditional lecture course.
Five biology classes with 720 students at the Kansas State
Teachers College in Emporia, Kansas, participated in the study.
The...
Anomaly timescales for the last 90 million years, derived from
marine magnetic profiles and published prior to mid-1979, are summarized,
illustrated for comparison, and critically reviewed. A revised timescale
is constructed using calibration points which fix the ages of anomalies
2.3', 5.5, 24, and 29. An equation is presented for...
Ponderosa pine is an important species both commercially and ecologically in western North America. This study considers the incidence of insect and disease pests on a series of replicated ponderosa pine research plantations in northern California. The studies, on an environmental gradient, contain a series of silvicultural treatments including vegetation...
Concerns over the possibility of exotic pest
introductions from eastern Russia to the West Coast of the United States due to proposed log imports raises the question of the effectiveness of possible mitigation measures. Toxicity of methyl bromide to representative pathogenic fungi was tested by exposing Armillaria ostoyae, Heterobasidion annosum,...
The effect of increased manganese superoxide dismutase (Mn-SOD) and cytosolic ascorbate peroxidase (cAPX) on various abiotic stresses was studied using transgenic tomato (Lycopersicon esculentum) plants. Transformants were selected in vitro based on kanamycin resistance, confirmed by PCR and northern blot analyses. Northern blots showed an enhanced gene expression of Mn-SOD...
Phytophthora ramorum, an oomycete plant pathogen, is the causal agent of sudden oak death, a serious disease of Fagaceous trees in California and Oregon over the last decade. Tanoak (Notholithocarpus densiflorus) is one of the most susceptible host species, but the cause of host mortality is poorly understood. Previous research...
Basal area and height growth were analyzed for individual trees in uneven-aged ponderosa and lodgepole pine stands in central Oregon. Basal area growth was modeled as a function of other stand and tree variables to address five general objectives: 1) to compare the predictive ability of distance-dependent versus distance-independent stand...
Phytophthora lateralis is the causal agent of cedar root rot, a fatal forest pathogen whose principal host is Chamaecyparis lawsoniana (Port-Orford-cedar), a predominantly riparian-restricted endemic tree species of ecological, economical, and cultural importance to coastal Oregon and California. Local scale distribution of P. lateralis is thought to be associated with...
Two theoretical models were examined based on the contributions of
preservice teachers' personal teaching efficacy, ethnic causal attributions, past
teaching, and international interaction experiences to their behaviors toward
international children in multicultural small group activity sessions. Path analytic
results revealed that for both models, these variables together did not significantly...
As the information-processing and telecommunications revolutions now underway will continue to change our life styles in the rest of the 21st century, our personal and economic lives rely more and more on our ability to transact over the electronic medium in a secure way. The privacy, authenticity, and integrity of...