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...
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 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...