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...
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,...
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...
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...
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...
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...
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...
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...
Although the occurrence of ketosis is a postpartum phenomenon, recent studies have
focused on the prepartum period as key in the development of the disorder. Indicators of
prepartum energy status, such as depressed dry matter intake (DMI) and elevated plasma
non-esterified fatty acid (NEFA) concentrations have been associated with the...
The ability to faithfully replicate DNA is dependent upon the maintenance
and regulation of its precursors, the deoxyribonucleoside triphosphates.
Enzymes encoded by the bacteriophage T4 have been widely used as models
of biochemical processes. A body of evidence supports the concept that the
bacteriophage T4 enzymes involved in deoxyribonucleotide biosynthesis...
This paper presents a model of the determination of excise tax rates by studying the
substantial variation in the state excise taxes in the U.S. brewing industry. Two
approaches are used. First, assuming that the government is only interested in the public
interest, a socially optimal tax rate is derived....
In broiler operations, various health problems develop during the final two weeks of the growing period, resulting in increased mortality and condemnation losses. At this stage, sickly birds were found to be systemically infected by various bacteria regardless of varied clinical signs. The main objective of the present study was...
The purpose of this study was to determine if significant
relationships exist among terminal values, demographic variables and
health care preferences for information and behavioral involvement for
graduate students from the People's Republic of China and Taiwan.
The Rokeach Value Survey and the Krantz Health Opinion Survey
were used to...
The purpose of this study was to analyze and interpret the results
of fall term student ratings of faculty teaching performance (n= 40,000)
in order to determine whether relationships exist between a range of
demographic variables and the ratings professors receive from students
enrolled in their classes. A population of...