A model for nematode locomotion in soil
H. William Hunt, Diana H. Wall, Nicole DeCrappeo, John S. Brenner
2001, Nematology (3) 705-716
Locomotion of nematodes in soil is important for both practical and theoretical reasons. We constructed a model for rate of locomotion. The first model component is a simple simulation of nematode movement among finite cells by both random and directed behaviours. Optimisation procedures were used to fit the simulation output...
Characteristics of water-well yields in part of the Blue Ridge Geologic Province in Loudoun County, Virginia
D. M. Sutphin, L.J. Drew, J.H. Schuenemeyer, W.C. Burton
2001, Natural Resources Research (10) 1-20
Loudoun County, Virginia, which is located about 50 km to the west of Washington, DC, was the site of intensive suburban development during the 1980s and 1990s. In the western half of the county, the source of water for domestic use has been from wells drilled into the fractured crystalline...
Diamond-anvil cell observations of a new methane hydrate phase in the 100-MPa pressure range
I.-M. Chou, A. Sharma, R.C. Burruss, R.J. Hemley, A.F. Goncharov, L.A. Stern, S. H. Kirby
2001, Journal of Physical Chemistry A (105) 4664-4668
A new high-pressure phase of methane hydrate has been identified based on its high optical relief, distinct pressure-temperature phase relations, and Raman spectra. In-situ optical observations were made in a hydrothermal diamond-anvil cell at temperatures between -40?? and 60 ??C and at pressures up to 900 MPa. Two new invariant...
Volcano monitoring using the Global Positioning System: Filtering strategies
K.M. Larson, Peter Cervelli, M. Lisowski, Asta Mikijus, P. Segall, S. Owen
2001, Journal of Geophysical Research B: Solid Earth (106) 19453-19464
Permanent Global Positioning System (GPS) networks are routinely used for producing improved orbits and monitoring secular tectonic deformation. For these applications, data are transferred to an analysis center each day and routinely processed in 24-hour segments. To use GPS for monitoring volcanic events, which may last only a few hours,...
Effects of Land-Cover Change, Floods, and Stream Position on Geomorphic Processes - Implications for Restoration Activities
F. A. Fitzpatrick
Hayes D.F.Hayes D.F., editor(s)
2001, Conference Paper, Proceedings of the 2001 Wetlands Engineering and River Restoration Conference
A geomorphic study for North Fish Creek, a northern Wisconsin tributary to Lake Superior was analyzed to determine the hydrologic and geomorphic changes caused by clear-cut logging and agricultural activity. Discharge magnitude estimated with HEC-2 for full-channel capacities indicate that modern full-channel discharges are about twice as large as pre-1946...
Using GIS to analyze animal movements in the marine environment
Philip N. Hooge, William M. Eichenlaub, Elizabeth K. Solomon
Gordon H. Kruse, Nicolas Bez, Anthony Booth, Martin W. Dorn, Susan Hills, Romuald N. Lipcius, Dominique Pelletier, Claude Roy, Stephen J. Smith, David B. Witherell, editor(s)
2001, Conference Paper, Spatial processes and management of marine populations
Advanced methods for analyzing animal movements have been little used in the aquatic research environment compared to the terrestrial. In addition, despite obvious advantages of integrating geographic information systems (GIS) with spatial studies of animal movement behavior, movement analysis tools have not been integrated into GIS for either aquatic or...
Uncertainty and spatial linear models for ecological data
Jay M Ver Hoef, Noel Cressie, Robert N. Fisher, Ted J. Case
C. Hunsaker, M. Goodchild, Mark A. Friedl, Ted J. Case, editor(s)
2001, Book chapter, Spatial uncertainty in ecology
Models are not perfect; they do not fit the data exactly and they do not allow exact prediction. Given that models are imperfect, we need to assess the uncertainties in the fits of the models and their ability to predict new outcomes. The goals of building models for scientific problems...
North Pacific decadal climate variability since 1661
Franco Biondi, Alexander Gershunov, Daniel R. Cayan
2001, Journal of Climate (14) 5-10
Climate in the North Pacific and North American sectors has experienced interdecadal shifts during the twentieth century. A network of recently developed tree-ring chronologies for Southern and Baja California extends the instrumental record and reveals decadal-scale variability back to 1661. The Pacific decadal oscillation (PDO) is closely matched by the...
Colletotrichum as a model system for defining the genetic basis of fungal symbiotic lifestyles
R. J. Rodriguez, R. S. Redman
2001, Report, Host specificity, pathology and host pathogen interactions of Colletotrichum
Abstract not available ...
National digital elevation program (NDEP)
K. Osborn, J. List, D.B. Gesch, J. Crowe, G. Merrill, E. Constance, J. Mauck, C. Lund, V. Caruso, J. Kosovich
2001, Book chapter, Digital elevation model technologies and applications—the DEM users manual
No abstract available....
Estimation of brood and nest survival: Comparative methods in the presence of heterogeneity
Bryan F.J. Manly, Joel A. Schmutz
2001, Journal of Wildlife Management (65) 258-270
The Mayfield method has been widely used for estimating survival of nests and young animals, especially when data are collected at irregular observation intervals. However, this method assumes survival is constant throughout the study period, which often ignores biologically relevant variation and may lead to biased survival estimates. We examined...
Lichens from St. Matthew and St. Paul Islands, Bering Sea, Alaska
Stephen S. Talbot, Sandra Looman Talbot, John W. Thomson, Wilfred B. Schofield
2001, The Bryologist (104) 47-58
One hundred thirty-nine taxa of lichens including two lichen parasites are reported from St. Matthew and St. Paul Islands in the Bering Sea. Caloplaca lithophila is new to Alaska. Wide-ranging arctic-alpine and boreal species dominate the lichens; a coastal element is moderately represented, while amphi-Beringian species form a minor element....
Interactive visualization of vegetation dynamics
B. C. Reed, D. Swets, L. Bard, J. Brown, James Rowland
2001, Conference Paper, International Geoscience and Remote Sensing Symposium (IGARSS)
Satellite imagery provides a mechanism for observing seasonal dynamics of the landscape that have implications for near real-time monitoring of agriculture, forest, and range resources. This study illustrates a technique for visualizing timely information on key events during the growing season (e.g., onset, peak, duration, and end of growing season),...
Identifying variably saturated water-flow patterns in a steep hillslope under intermittent heavy rainfall
A. I. El-Kadi, J.D. Torikai
2001, Hydrogeology Journal (9) 231-242
The objective of this paper is to identify water-flow patterns in part of an active landslide, through the use of numerical simulations and data obtained during a field study. The approaches adopted include measuring rainfall events and pore-pressure responses in both saturated and unsaturated soils at the site. To account...
Macroinvertebrate instream flow studies after 20 years: A role in stream management and restoration
James A. Gore, James B. Layzer, Jim Mead
2001, Regulated Rivers: Research & Management (17) 527-542
Over the past two decades of refinement and application of instream flow evaluations, we have examined the hydraulic habitat of aquatic macroinvertebrates in a variety of conditions, along with the role of these macroinvertebrates in sustaining ecosystem integrity. Instream flow analyses assume that predictable changes in channel flow characteristics can,...
Density structure of the lithosphere in the southwestern United States and its tectonic significance
M.K. Kaban, Walter D. Mooney
2001, Journal of Geophysical Research B: Solid Earth (106) 721-739
We calculate a density model of the lithosphere of the southwestern United States through an integrated analysis of gravity, seismic refraction, drill hole, and geological data. Deviations from the average upper mantle density are as much as ?? 3%. A comparison with tomographic images of seismic velocities indicates that a...
Rehabilitation of gypsum-mined lands in the Indian desert
K.D. Sharma, S. Kumar, L. P. Gough
2001, Arid Soil Research and Rehabilitation (15) 61-76
The economic importance of mining in the Indian Desert is second only to agriculture. Land disturbed by mining, however, has only recently been the focus of rehabilitation efforts. This research assesses the success of rehabilitation plans used to revegetate gypsum mine spoils within the environmental constraints of the north-west Indian...
Moss and lichen cover mapping at local and regional scales in the boreal forest ecosystem of central Canada
G. Rapalee, L. T. Steyaert, F.G. Hall
2001, Journal of Geophysical Research D: Atmospheres (106) 33551-33563
Mosses and lichens are important components of boreal landscapes [Vitt et al., 1994; Bubier et al., 1997]. They affect plant productivity and belowground carbon sequestration and alter the surface runoff and energy balance. We report the use of multiresolution satellite data to map moss and lichens over the BOREAS region...
Coastline complexity: A parameter for functional classification of coastal environments
J.D. Bartley, R. W. Buddemeier, D.A. Bennett
2001, Conference Paper, Journal of Sea Research
To understand the role of the world's coastal zone (CZ) in global biogeochemical fluxes (particularly those of carbon, nitrogen, phosphorus, and sediments) we must generalise from a limited number of observations associated with a few well-studied coastal systems to the global scale. Global generalisation must be based on globally available...
Sex-biased gene flow in spectacled eiders (Anatidae): Inferences from molecular markers with contrasting modes of inheritance
Kim T. Scribner, Margaret R. Petersen, Raymond L. Fields, Sandra L. Talbot, John M. Pearce, Ronald K. Chesser
2001, Evolution (55) 2105-2115
Genetic markers that differ in mode of inheritance and rate of evolution (a sex-linked Z-specific microsatellite locus, five biparentally inherited microsatellite loci, and maternally inherited mitochondrial [mtDNA] sequences) were used to evaluate the degree of spatial genetic structuring at macro- and microgeographic scales, among breeding regions and local nesting populations...
Flow of variably fluidized granular masses across three-dimensional terrain 2. Numerical predictions and experimental tests
R.P. Denlinger, R.M. Iverson
2001, Journal of Geophysical Research B: Solid Earth (106) 553-566
Numerical solutions of the equations describing flow of variably fluidized Coulomb mixtures predict key features of dry granular avalanches and water-saturated debris flows measured in physical experiments. These features include time-dependent speeds, depths, and widths of flows as well as the geometry of resulting deposits. Threedimensional (3-D) boundary surfaces strongly...
Processes of nickel and cobalt uptake by a manganese oxide forming sediment in Pinal Creek, Globe mining district, Arizona
J.T. Kay, M.H. Conklin, C. C. Fuller, P. A. O’Day
2001, Environmental Science & Technology (35) 4719-4725
A series of column experiments was conducted using manganese oxide coated sediments collected from the hyporheic zone in Pinal Creek (AZ), a metal-contaminated stream, to study the uptake and retention of Mn, Ni, and Co. Experimental variables included the absence (abiotic) and presence (biotic) of active Mn-oxidizing bacteria, the absence...
Transport processes near coastal ocean outfalls
M.A. Noble, C. R. Sherwood, Hooi-Ling Lee, J. Xu, P. Dartnell, G. Robertson, M. Martini
2001, Conference Paper, Oceans Conference Record (IEEE)
The central Southern California Bight is an urbanized coastal ocean where complex topography and largescale atmospheric and oceanographic forcing has led to numerous sediment-distribution patterns. Two large embayments, Santa Monica and San Pedro Bays, are connected by the short, very narrow shelf off the Palos Verdes peninsula. Ocean-sewage outfalls are...
Earthquake stress drop and laboratory-inferred interseismic strength recovery
N.M. Beeler, S.H. Hickman, T.-F. Wong
2001, Journal of Geophysical Research B: Solid Earth (106) 30701-30713
We determine the scaling relationships between earthquake stress drop and recurrence interval tr that are implied by laboratory-measured fault strength. We assume that repeating earthquakes can be simulated by stick-slip sliding using a spring and slider block model. Simulations with static/kinetic strength, time-dependent strength, and rate- and state-variable-dependent strength indicate that the...
Permeability reduction in granite under hydrothermal conditions
C.A. Morrow, Diane E. Moore, D.A. Lockner
2001, Journal of Geophysical Research B: Solid Earth (106) 30551-30560
The formation of impermeable fault seals between earthquake events is a feature of many models of earthquake generation, suggesting that earthquake recurrence may depend in part on the rate of permeability reduction of fault zone materials under hydrothermal conditions. In this study, permeability measurements were conducted on intact, fractured, and...
