The growing population of Oregon’s Willamette River Basin places an increasing demand on the basin’s surface waters. Watershed-scale research addressing spatial trends of dissolved nitrogen (DN) and its relationship with landuse and soil N dynamics, such as N mineralization, is sparse in the Willamette Basin. I measured DN along 124...
Birdsfoot trefoil (Lotus corniculatus L.) is a popular perennial, non-bloating forage legume used for pasture, hay and silage throughout the temperate regions of Europe, Asia Minor, North Africa and North and South America. It is regarded as the most morphologically and biochemically variable species in the genus. Research investigating the...
Runoff from agricultural lands into Upper Klamath Basin rivers and lakes can
cause water quality problems affecting fish and wildlife. Excessive eutrophication
in Upper Klamath Lake is linked to high nutrient input (particularly phosphorus)
stemming from both lake sediments and watershed tributaries.
On a unit area load basis the Wood...
The utilization of ⁷⁷ [superscript m] Se, half life 17.5 s, and ⁷⁵ Se, half life 119.8 d, for quantification of trace amounts of Se in well water and biological materials by means of instrumental neutron activation analysis (INAA) is described. A Se detection limit of 0.03 ppm was achieved...
The Calapooia River, a major tributary of the Willamette River in western Oregon, is a watershed typical of many found in the Willamette Basin. Public and private forested lands occur in the steep Upper Zone of the watershed, mixed forest and agriculture lands are found in the Middle Zone, and...
Cereal and commercial grass-seed straws are abundant plant biomass materials that are currently being considered for application in industrial processes aimed at the production of biofuels, biomaterials, and biochemicals. The carbohydrate fraction of these straws is of particular interest in this context due to its chemical functionality and relative ease...
Durum wheat cultivars for North-Eastern Oregon have to be competitive
in terms of their yield potential with soft white winter wheat cultivars and meet
strict quality requirements of the milling industry. Combining the high yield
potential of fall planted durum wheat cultivars which have an acceptable level of
winter hardiness...
The purpose of this study was to investigate the effect of the levels of group cooperation on students' achievement during a series of physical science laboratory activities. Six intact seventh grade physical science classes taught by two teachers, with each teacher instructing three classes, were selected from two middle schools....
In this thesis, A nonlinear methodology for the control of the highly
maneuverable, high performance aircraft HARV (F-18) is studied by using sliding-mode
control (SMC). This control law, which takes a continuous function when the
input constraints are not considered, satisfies the reachability condition by which
concerned states are driven...
The pulse-coupled oscillator model is widely used to simulate the dynamics of neural systems. For networks with particular internal (Mirollo-Strogatz) dynamics, I will define three broad patterns of collective behaviors found in literature in terms of inter-spike interval (ISI) statistics. These patterns are i) temporally-regular, characterized by all oscillators in...
The purposes of this study were to develop a valid and
reliable attitudes toward science instrument in the Thai
language and determine the differences in attitudes toward
science and achievement in physical and biological science
of Thai boys and girls in lower secondary education.
The population consisted of 709 students,...
The cultivated sunflower (Helianthus annuus L., x=17) is one of the most important annual oilseed crops in the world. There are very few publicly shared sequence-based DNA markers and genetic maps in sunflower, even though molecular DNA markers and genetic maps have become widely used in all areas of genetic...
Controls of substrate quality, temperature, and moisture on woody root decomposition in the Pacific Northwest were explored using chronosequences, time series, laboratory incubations, and simulation modeling approaches at three sites: Cascade Head
(CAH), H. J. Andrews (HJA), and Pringle Falls Experimental Forests (PRF). In the chronosequence study, a structural component-oriented...
In this study, we used a combination of conventional statistical analyses and mechanistic bioenergetics models to understand the potential effects of environmental variability on growth of stream-living fishes in four headwater streams subject to upstream forest harvest. We focused on two common fish consumers in headwater streams in the Pacific...
Clock-feedthrough effects, channel-length modulation and device mismatch are
the main causes of the inaccuracy of Switched-Current (SI) circuits. In this paper, these
non-ideal effects are analyzed. A high-performance current mirror, namely regulated
cascode current mirror, which eliminates drain voltage variation problem is introduced.
By using this current mirror as a...
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...
A MOS biquadratic (biquad) filter employing the switched-current technique is
reported. The circuit uses current-mode processing which can offer wide
bandwidth, low voltage operation, and can be implemented with standard CMOS
technology. Examples of lowpass, highpass, and bandpass filters are given
which illustrate the synthesis procedures and the versatility of...
The output characteristics of a conventional GaAs depletion-mode MESFET device have been investigated. One of the important parameters of the small-signal GaAs MESFET model, g[subscript ds] (output conductance), is shown to be frequency and temperature dependent. Variations in g[subscript ds] are a serious problem in many analog and digital circuits...
In this dissertation, two important current mode circuit design subjects have
been explored. In the first part, the switched-current circuit technique has been
investigated. The fundamental performance and limitations of this technique are
explored. One of the major limitations, the signal distortion caused by clock
feedthrough has been substantially reduced...
Although the biology of Bradyrhizobium has been studied for almost
one hundred years, virtually nothing is known about the ecology and genetic
variation in natural soil populations of this genus. The majority of
information has been obtained from studies of one species, Bradyrhizobium
japonicum, and the diversity within soil populations...
Nearly 80% of solid tumors, such as melanoma, metastasize via the lymphatic system. The most common form of melanoma is BRAF-mutant melanoma, and additional mutations, such as a PTEN mutation in the PI3K pathway, is required for metastases to occur. Standard therapy includes treatment with small molecules dabrafenib (DAB) and...
In this thesis the concept of inhomogeneous
dielectrics is demonstrated for various optical coating
applications. Compositionally-varying silicon oxynitride
(SiON) dielectric layers, with the refractive index
varying as a function of position, are grown by computer-controlled
plasma-enhanced chemical vapor deposition
(PECVD) using silane, nitrogen, and nitrous oxide reactant
gases. Compositionally graded...
Layered multiconductor coupled slot and strip-slot structures are characterized by introducing the full-wave modal analysis as well as the quasi-TEM spectral domain technique. In the modal analysis, the electric and magnetic fields are constructed in terms of modal fields in different regions. Application of the boundary conditions at interfaces for...
Breeding ecology and behavior were investigated in a field study of three sympatric anuran amphibians in the Oregon Cascade Mountains: the western toad (Bufo
boreas), the Cascades frog (Rana cascadae) and the Pacific treefrog (Hyla regilla). A comprehensive study of the western toad mating system was conducted at three populations...
A method based on fatty acid (FA) analysis is used to profile microbial community structure (MCS). Various extraction protocols are available, which alter the types of FAs extracted from soils. The more time consuming but widely used protocol extracts only FAs from phospholipids (PLFA). This technique is desirable because PLFAs...
The tracheal mite, Acarapis woodi (Rennie), parasitizes the
honey bee, Apis mellifera L., an insect used extensively by humans
for pollination of domestic crops and for bee products, primarily
honey.
This parasite was first discovered in 1921 on the Isle of
Wight, a small island situated in the English Channel...