Methodologies that detect biologically active substances have important potential applications for medical diagnostics, drug discovery, and chemical and biological anti-terrorism efforts. The wide spectrum of potential analytes that induce a physiological response dictates that novel techniques be developed to more rapidly screen and characterize agents that are more economical and...
Understanding the drivers of species occurrence is a fundamental goal in basic and applied ecology. Occupancy models have emerged as a popular approach for inferring species occurrence because they account for problems associated with imperfect detection in field surveys. Current models, however, are limited because they assume covariates are independent...
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Understanding the drivers of species occurrence is a fundamental goal in basic and applied ecology. Occupancy models have emerged as a popular approach for inferring species occurrence because they account for problems associated with imperfect detection in field surveys. Current models, however, are limited because they assume covariates are independent...
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Methods & Research R-253:226–284.
Pearl, J. 2000. Causality. Cambridge, New York.
Preston, D. L., J. S
Understanding the drivers of species occurrence is a fundamental goal in basic and applied ecology. Occupancy models have emerged as a popular approach for inferring species occurrence because they account for problems associated with imperfect detection in field surveys. Current models, however, are limited because they assume covariates are independent...
Describing the mechanisms that drive variation in species interaction strengths is central to understanding, predicting, and managing community dynamics. Multiple factors have been linked to trophic interaction strength variation, including species densities, species traits, and abiotic factors. Yet most empirical tests of the relative roles of multiple mechanisms that drive...
High-elevation aquatic ecosystems are highly vulnerable to climate change, yet relatively few records are available to characterize shifts in ecosystem structure or their underlying mechanisms. Using a long-term data set on seven alpine lakes (3126 to 3620 m) in Colorado, USA, we show that ice-off dates have shifted 7 days earlier over...
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, Diane M. McKnight2,4, Mark W. Williams2,3, 7
Katherina Hell2, Matthew P. Miller5, Sarah J. Hart3
High-elevation aquatic ecosystems are highly vulnerable to climate change, yet relatively few records are available to characterize shifts in ecosystem structure or their underlying mechanisms. Using a long-term data set on seven alpine lakes (3126 to 3620 m) in Colorado, USA, we show that ice-off dates have shifted 7 days earlier over...
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Citation:
Preston, D. L., N. Caine, D. M. McKnight,
M. W. Williams, K. Hell, M. P. Miller,
S. J. Hart, and
High-elevation aquatic ecosystems are highly vulnerable to climate change, yet relatively few records are available to characterize shifts in ecosystem structure or their underlying mechanisms. Using a long-term data set on seven alpine lakes (3126 to 3620 m) in Colorado, USA, we show that ice-off dates have shifted 7 days earlier over...
Numerous tests were applied to rainbow trout
of eleven months of age to determine whether
ascorbic acid is an essential element of the diet
of these fish. Although previous work had been
done on this question, conflicts in the results,
the large reliance upon abnormal symptoms such as
lordosis and...
Reduction of pocket gopher damage to conifer seedlings is important to successful reforestation in many regions of the Pacific
Northwest. The objective of this study was to determine the factors that influence the local distribution of the northern pocket gopher (Thomomys talpoides Richardson) in a forested region of south-central Oregon....
The role of each habitat fish use is of great importance to the dynamics of populations. During
their early marine residence, Chinook salmon (Oncorhynchus tshawytscha), an anadromous fish
species, mostly inhabit estuaries but also use sandy beach surf zones and the coastal ocean.
However, the role of surf zones in...
Large quantities of smaller diameter materials are available in the overstocked forests of eastern Oregon and Washington, but the costs of removing these materials and the long distances from markets sharply reduce the potential of this resource. Failure to thin these forests will sharply increase the likelihood of catastrophic wildfires....
The inter-relationships among δ¹³C and δ¹⁸O in tree ring cellulose and ring width have the potential to illuminate long-term physiological and environmental information in forest stands that have not been monitored. We examine how within-stand competition and environmental gradients affect ring widths and the stable isotopes of cellulose. We utilize...
The wine grape industry is rapidly growing in Oregon. By the year 2005, we could predict that Oregon will have over 10,000 acres in wine grape production. At a meeting last year, the Grapevine Improvement Committee acknowledged that little was known about the presence of potential pest and beneficial insects...
The behavior of low-frequency baroclinic Rossby wave motion in the vicinity of coastal boundaries is investigated using linearized modulated wave theory in a stratified, constant-depth, equatorial β-plane ocean. A primary objective is to obtain an equation that describes large-scale, low-frequency pressure fluctuations along variable geometry ocean boundaries at all latitudes...
The Northwest Lau Backarc Basin, consisting of the Northwest Lau Spreading Center (NWLSC) and the Rochambeau Rifts (RR), is unique in having elevated ³He/⁴He ratios (up to 28 R[subscript a]) in the erupted lavas, clearly indicating a hot spot or ocean island basalt (OIB)-type signature. This OIB-type helium signature does...
Stable isotopes can be a valuable tool for tracing the redistribution, storage, and evaporation of water associated with canopy
interception of rainfall. Isotopic differences between throughfall and rainfall have been attributed to three mechanisms:
evaporative fractionation, isotopic exchange with ambient vapor, and temporal redistribution. We demonstrate the potential
importance of...
Sandy beach surf zones serve as alternative nursery habitats for juvenile Chinook salmon (0 age) during their early marine residency, a period considered critical due to high and variable mortality rates. Despite the importance of early marine residence, the extent of juvenile salmon surf zone use and movement along sandy...
Glucose-dependent growth of the luxCDABE reporter bacterium Pseudomonas fluorescens HK44 was monitored noninvasively in quartz sand under unsaturated-flow conditions within a 45- by 56- by 1-cm two-dimensional light transmission chamber. The spatial and temporal development of growth were mapped daily over 7 days by quantifying salicylate-induced bioluminescence. A nonlinear model...
A novel analytical method was developed that permitted real-time, noninvasive measurements of microbial growth and associated changes in hydrodynamic properties in porous media under unsaturated flowing conditions. Salicylate-induced, lux gene-based bioluminescence was used to quantify the temporal and spatial development of colonization over a 7-day time course. Water contents were...
Metal-plate-connected wood trusses with semi-rigid joints were investigated by the matrix method of structural analysis. The element-stiffness matrix and fixed-end forces of an individual member with one or both ends semi-rigid were derived as modifications of the idealized cases. The case of unequal elastic connections at two ends of a...
Strong modulation of turbulent mixing by a westward-propagating tropical instability wave (TIW) was observed in the stratified shear layer between the equatorial undercurrent (EUC) and the surface mixed layer during October and November 2008 at 0°N 140°W. The unique deep diurnal-cycle mixing in the stratified layer beneath the equatorial cold...
Turbulence measurements from the central equatorial Pacific in February 1982 have been analyzed and compared to synoptic CTD and current velocity profiles and current meter data. These suggest considerably more time (if not space) variability than had previously been anticipated. Above 300 m at the equator the turbulence levels were...
Collocated Moderate Resolution Imaging Spectroradiometer (MODIS) imagery and
Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) 532 nm
total attenuated backscatter coefficients were used to identify 50 km scale segments
for ocean regions that had only a single layer of marine stratocumulus. On the basis of
whether the underlying ocean...
A series of profiles of velocity microstructure along 152°E in the western North Pacific Ocean were collected in May–June 1982. Large, averaged turbulent dissipation rates, ϵ, found in the main thermocline (400 to 1000 m) were determined by a combination of large independent estimates of ϵ and a greater rate...
Current and hydrographic observations from the Coastal Mixing and Optics
experiment moored array, deployed from August 1996 through June 1997, are used to
describe the velocity variability and evaluate the dynamics of circulation over the New
England shelf on timescales ranging from a few days to several months. Subtidal (days...
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on the New
England shelf’’
R. Kipp Shearman and Steven J. Lentz
Received 22 December 2006
Current and hydrographic observations from the Coastal Mixing and Optics
experiment moored array, deployed from August 1996 through June 1997, are used to
describe the velocity variability and evaluate the dynamics of circulation over the New
England shelf on timescales ranging from a few days to several months. Subtidal (days...
Full Text:
on the New
England shelf’’
R. Kipp Shearman and Steven J. Lentz
Received 22 December 2006
Current and hydrographic observations from the Coastal Mixing and Optics experiment moored array, deployed from August 1996 through June 1997, are used to describe the velocity variability and evaluate the dynamics of circulation over the New England shelf on timescales ranging from a few days to several months. Subtidal (days...