Xylem anatomy is a strong determinant of water transport efficiency and is therefore an important component of the overall hydraulic strategy of any woody plant.
However, in addition to its role in water transport, xylem also serves in mechanical
support, and these two functions may represent conflicting design requirements. To...
• Compression wood has been shown to reduce stem permeability, but it is not known to what extent it affects leaf‐level processes. Here, we report whole‐plant hydraulic properties of Douglas‐fir (Pseudotsuga menziesii) seedlings induced to form varying amounts of compression wood.
• Seedlings were grown under three bending treatments to...
Stem sinuosity is thought to negatively impact wood quality, but no studies have characterized its vertical and radial effects on wood properties. Here we study wood quality along the entire stem in 25-year-old plantation grown Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) trees (32 trees total) that had been scored...
The factors that determine sapwood width and volume in a tree are not known. This study asked whether sapwood width is related to a need for stem storage sites. Experiments were conducted on 12 34-year-old Douglas-fir [(Pseudotsuga menziesii (Mirb.) Franco] trees with a 6-7 fold range of leaf areas and...
Heartwood durability of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) was studied as a function of vertical and radial position in boles of trees with a wide range of leaf area/sapwood area ratios. Six 34- year-old trees were harvested from each of three plots established 14 years before: very dense,...
A wealth of information on plant anatomy and morphology is available in the current and historical literature, and molecular biologists are producing massive amounts of transcriptome and genome data that can be used to gain better insights into the development, evolution, ecology, and physiological function of plant anatomical attributes. Integrating...
Southeast Alaska is located on the traditional territory of the Lingít, Haida, and Tsimshian People. It is comprised of the largest temperate rainforest in the world, with subregions receiving over 500 cm of rain annually. Climate change is predicted to alter the region's timing, type, and magnitude of precipitation and...
Interferon tau (IFN-τ) is the pregnancy recognition signal secreted by the trophectodermal cells of the developing bovine embryo that prevents luteolysis and maintains critical progesterone production. Recent evidence has suggested in addition to the mechanism of action identified in the uterus, there may be a direct effect of IFN-τ on...
An important aspect in device technology is the
processing of GaAs to produce highly-resolved etch
patterns on the substrate. This is done typically on the
GaAs(100) surface. Recently, a number of methods, all
using chlorinated vapor reactants, have been applied to
fabrication of GaAs devices. In spite of these
technological...
Cystic ovarian disease (COD) is an anovulatory condition in cattle
that afflicts between 6-18% of all dairy cows in the US. Ovulation is
dependent on the plasminogen activator (PA) family of proteases
and protease inhibitor for proteolysis, culminating in follicular rupture.
Failure of the follicle to ovulate suggests an aberration...
Biologists have long been fascinated with reproductive traits, in part because they are frequently exaggerated or showy, and they commonly vary among closely related species. Exaggerated sexual traits, in particular, have been the focus of intense empirical and theoretical research, but most of this work has focused on traits involved...
I studied developmental rates in a suite of temperate and tropical passerine bird species from the New World to test the hypothesis that tropical passerines exhibit slower patterns of growth and development than temperate birds. I also investigated how the expression of several developmental rates varied with life history traits...
The roles of fabrics in subdrains are identified for normal
groundwater flow conditions to determine hydraulic and pore characteristics
necessary for design considerations. Two conditions are discussed:
(1) the fabric in direct contact with the soil to provide
mechanical support, and (2) the fabric as a filter to remove soil...
Managing Microdochium patch on intensively manicured annual bluegrass putting greens is a challenge for turfgrass professionals in cool-humid climates similar to the Pacific Northwest. Fungicides are the predominant means to mitigate damage caused by this fungal pathogen, however pesticide restrictions are making it even more challenging to suppress Microdochium patch....
Archaeological investigations can reveal persistent traditions of ethnic
groups. Hawaiians were employed in the fur trade of the Columbia River from
1810 through 1850. The Hudson's Bay Company employed them at Ft.
Vancouver, Washington from 1825 through the end of this period. Data from
the excavations of the servant's village...
Tanoak (Lithocarpus densiflorus), along with some other members of Fagaceae, are susceptible to sudden oak death caused by the oomycete Phytophthora ramorum. Symptoms of the disease include dying crowns, bleeding cankers, and eventually death of infected trees. The cause of mortality is not well understood, but recent research indicates that...
Coagulation and flocculation are commonly used in drinking water treatment
as a means of destabilizing and aggregating particles and promoting adsorption of
dissolved organic carbon (DOC). In practice, jar tests are used to determine optimal
conditions for the removal of turbidity and DOC. However, beyond the inferences
that can be...
It has been just over five years since the first ‘Canine Special Issue’ was published in Behavioral Processes. As predicted in that issue, we have seen exponential growth in the number of researchers studying canine behavior, and consequently in the number of new publications arising from laboratories around the world....
Relatively little is known about wintering bird communities in lowlands of the Pacific Northwest, yet, the condition of winter habitats potentially can pose a major constraint on bird populations. I initiated a study to determine: (1) Which avian species use lowland riparian and wetland habitats in the Willamette Valley during...
Stem sinuosity is a highly visible stem-form trait in the leaders of fast-growing Douglas-fir (Pseudotsuga menziesii var. (Mirb.) Franco) trees, yet its cause is unknown. We tested the hypotheses that sinuous stems have longer expanses of primary growth than nonsinuous stems (putting the leader at higher risk curvature, induction of...
North American bighorn sheep (Ovis canadensis) have experienced significant declines and population extirpations due to novel pathogens such as Mycoplasma ovipneumoniae. This disease continues to limit the population restoration of bighorn sheep. Therefore, understanding the demographic consequences of pathogen presence and the risk of contact between bighorn populations and potential...
The application of laser generated ultrasonics was first
demonstrated in the mid-seventies and has shown good potential
when applied to isotropic materials. However, its use with
composite materials is still in the early stages of development.
This study explores the potential for application of laser
generated Rayleigh and Lamb waves...
Few studies to date have demonstrated widespread biological impacts of ocean
acidification (OA) under conditions currently found in the natural environment.
From a combined survey of physical and chemical water properties
and biological sampling along the Washington–Oregon–California coast in
August 2011, we show that large portions of the shelf waters...
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in the California Current
Ecosystem
Bednaršek, N., Feely, R. A., Reum, J. C. P., Peterson, B
Tanoak (Lithocarpus densiflorus (Hook. and Arn.) Rehder) is highly susceptible to sudden oak death, a disease caused by the oomycete Phytophthora ramorum Werres, De Cock & Man in’t Veld. Symptoms include a dying crown, bleeding cankers, and, eventually, death of infected trees. The cause of mortality is not well understood,...
The purposes of the research presented in this thesis were
to: (l) assess the nutritional status of vegetarian and nonvegetarian
Seventh-day Adventists (SDA), non-SDA non-vegetarians,
and non-vegetarian hormone dependent cancer subjects; (2) determine
the relationship of various blood and urinary biochemical
parameters to dietary intake; (3) determine hormonal status in...
It would be valuable economically to know what are the biological triggers for formation of mature wood (currently of high value) and (or) what maintains production of juvenile wood (currently of low value), to develop silvicultural regimes that control the relative production of the two types of wood. Foresters commonly...
We report the first measurements of CO₂, CH₄,
N₂O, CO₂, and H₂O(g) in the exhaust trails of T-39, B-757, and
DC-8 aircraft at cruise conditions. Emission indices (El)
derived from these in-situ measurements are presented.
Results are in agreement with ground-based tests indicating
aircraft act as a net sink for...
Ongoing greenhouse gas emissions can modify climate processes and induce shifts in ocean temperature, pH, oxygen
concentration, and productivity, which in turn could alter biological and social systems. Here, we provide a synoptic global
assessment of the simultaneous changes in future ocean biogeochemical variables over marine biota and their broader...
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Mora1*, Chih-Lin Wei2, Audrey Rollo3, Teresa Amaro4, Amy R. Baco5, David Billett6,
Laurent Bopp7, Qi
Despite renewed interest in the nature of limitations on maximum tree height, the mechanisms governing ultimate and species-specific height limits are not yet understood, but likely involve water transport dynamics. Tall trees experience increased risk of xylem embolism from air-seeding because tension in their water column increases with height due...
The state of Oregon has two distinct climate types bisected by the crest of the Cascade Mountain range. The western side of the Cascades experiences high levels of precipitation and mild temperatures due to the maritime influence of the Pacific Ocean, while the eastern side lies in the rain shadow...
Neurofilament proteins are intermediate filaments found in the neuronal cytoskeleton. Phosphorylation of these proteins is considered important for the assembly and stability of the filaments. Accurate molecular weights have been difficult to measure, largely because the high degree of phosphorylation results in M[subscript r]'S that are significantly greater than dictated...
One of the important ‘hallmarks’ of cancer is angiogenesis, which is the process of formation of new blood vessels that are necessary for tumor expansion, invasion and metastasis. Under normal physiological conditions, angiogenesis is well balanced and controlled by endogenous proangiogenic factors and antiangiogenic factors. However, factors produced by cancer...
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...
Experiments were conducted to determine the influence of cultural management practices on weed growth in nursery containers. Experiments 1 and 2 evaluated the effects of dolomitic lime rate and application method on substrate pH, creeping woodsorrel (Oxalis corniculata L.) establishment in containers, and growth of azalea (Rhododendron ‘Rosebud’) and pieris...
Heartwood can have properties that are distinct from sapwood,
including resistance to insect and microbial attack. Despite the practical
importance of heartwood formation in trees, a review of the literature revealed
that little was known about the effects of environmental factors on heartwood
quality or how variations in heartwood properties...
This review presents a framework for evaluating how cells, tissues, organs, and whole plants perform both hydraulic and mechanical functions. The morphological alterations that affect dual functionality are varied: individual cells can have altered morphology; tissues can have altered partitioning to functions or altered cell alignment; and organs and whole...
In the first set of studies, 2 experiments evaluated the influence of supplement composition on ruminal forage disappearance, performance, and physiological responses of Angus × Hereford cattle consuming a low-quality, cool-season forage (8.7 % CP and 57 % TDN). In Exp. 1, 6 rumen-fistulated steers housed in individual pens were...
From measurements of thermal and electrical conductivities of
64 ocean sediment samples obtained from piston cores taken off the
Oregon Coast, and from 37 water-saturated sandstone samples analyzed
by Zierfuss and Van der Vliet (1956), as well as 51 thermal
conductivities and water contents of ocean sediments analyzed by
Ratcliffe...
The ability of plants and microorganisms to take up organic nitrogen in the form of free amino acids and oligopeptides has received increasing attention over the last two decades, yet the mechanisms for the formation of such compounds in soil environments remain poorly understood. We used Nuclear Magnetic Resonance (NMR)...
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.;
Donald, B. R.; Alam, S. M.; Haynes, B. F.; Spicer, L. D. Structure of an
HIV-1-neutralizing antibody
This study investigated variation in xylem anatomy, hydraulic properties, and the relationship between anatomy and properties within Douglas-fir trees at multiple scales. The hierarchical scales in the study included fertilization treatments (fertilized and unfertilized), trees within the treatments, and positions within the trees. Tracheid diameter, tracheid length, percent latewood, number...
This study investigated variation in xylem anatomy, hydraulic properties, and the relationship between anatomy and properties within Douglas-fir trees at multiple scales. The hierarchical scales in the study included fertilization treatments (fertilized and unfertilized), trees within the treatments, and positions within the trees. Tracheid diameter, tracheid length, percent latewood, number...
The Manual on Uniform Traffic Control Devices prohibits positioning a bike lane right-adjacent to a vehicle turn-only lane to mitigate the potential for right-hook crashes. However, it provides no specific guidance on positioning with respect to bus-only lanes. This thesis describes a before/after safety evaluation of bike lanes positioned left...
Ice crystal larger than about 5 μm diameter were separated from interstitial particles in aircraft contrails and evaporated. Residual particles larger than 0.1 μm were analyzed by electron microscopy. Soot, metals, and volatile organic substances, apparently from the aircraft exhaust, were found. However, the residual particles also contained high percentages...
Student activities and instructor-made models are described to facilitate and encourage other instructors to develop their own appropriate activities and models for teaching the three-dimensional structure of wood.
The teaching activities include making several annual rings with straws pushed into clay, drawing wood’s structure onto a piece of paper that...
The cohesion-tension theory of water transport states that hydrogen bonds hold water molecules together and that they are pulled through the xylem under tension. This tension could cause transport failure in at least two ways: collapse of the conduit walls (implosion), or rupture of the water column through air-seeding. The...
Two studies were conducted to evaluate the influence of supplement composition on intake and digestibility of a low-quality (< 6% CP), cool-season forage, as well as cow performance. Treatments included a non-supplemented control (CON), corn (approximately 8% CP), corn and urea (LU = corn + 0.09 mg/kg BW urea, approximately...
The ability of plants and microorganisms to take up organic nitrogen in the form of free amino acids and oligopeptides has received increasing attention over the last two decades, yet the mechanisms for the formation of such compounds in soil environments remain poorly understood. We used Nuclear Magnetic Resonance (NMR)...
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zero charge. B. Kaolinite point of zero charge.
1. Reardon, P. N.; Spicer, L. D
• Premise of the study: The pathway of radial water movement in tree stems presents an unknown with respect to whole-tree
hydraulics. Radial profi les have shown substantial axial sap fl ow in deeper layers of sapwood (that may lack direct connection
to transpiring leaves), which suggests the existence of...
Establishment of a non-native plant species in new habitats beyond their native range is associated with inherent changes in ecosystem properties. These changes may be dramatic or subdued, and consequences may be positive or negative depending on characteristics and response of the resident ecosystem. Non-native aquatic plant species in the...