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Page 1964, results 49076 - 49100

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Publication Extents

Not all publications have extents, not all extents are completely accurate
Vulnerability of a public supply well in a karstic aquifer to contamination
B. G. Katz, W.S. McBride, A.G. Hunt, C. A. Crandall, P. A. Metz, S. M. Eberts, M. P. Berndt
2009, Ground Water (47) 438-452
To assess the vulnerability of ground water to contamination in the karstic Upper Floridan aquifer (UFA), age-dating tracers and selected anthropogenic and naturally occurring compounds were analyzed in multiple water samples from a public supply well (PSW) near Tampa, Florida. Samples also were collected from 28 monitoring wells in the...
Sex, season, and time of day interact to affect body temperatures of the Giant Gartersnake
G.D. Wylie, Michael L. Casazza, B.J. Halstead, C.J. Gregory
2009, Journal of Thermal Biology (34) 183-189
1.We examined multiple hypotheses regarding differences in body temperatures of the Giant Gartersnake using temperature-sensitive radio telemetry and an information-theoretic analytical approach.2.Giant Gartersnakes selected body temperatures near 30 ??C, and males and females had similar body temperatures most of the year, except during the midsummer gestation period.3.Seasonal differences in the...
Web-client based distributed generalization and geoprocessing
E.B. Wolf, K. Howe
2009, Conference Paper, Proceedings of the International Conference on Advanced Geographic Information Systems and Web Services, GEOWS 2009
Generalization and geoprocessing operations on geospatial information were once the domain of complex software running on high-performance workstations. Currently, these computationally intensive processes are the domain of desktop applications. Recent efforts have been made to move geoprocessing operations server-side in a distributed, web accessible environment. This paper initiates research into...
Research in thermal biology: Burning questions for coldwater stream fishes
D.A. McCullough, J.M. Bartholow, H.I. Jager, R. L. Beschta, E.F. Cheslak, M.L. Deas, J. L. Ebersole, J.S. Foott, S. L. Johnson, K.R. Marine, M.G. Mesa, J.H. Petersen, Y. Souchon, K.F. Tiffan, W.A. Wurtsbaugh
2009, Reviews in Fisheries Science (17) 90-115
With the increasing appreciation of global warming impacts on ecological systems, in addition to the myriad of land management effects on water quality, the number of literature citations dealing with the effects of water temperature on freshwater fish has escalated in the past decade. Given the many biological scales at...
Symbiotic regulation of plant growth, development and reproduction
R. J. Rodriguez, D. Carl Freeman, E.D. McArthur, Y.-O. Kim, R. S. Redman
2009, Communitative and Integrative Biology (2) 141-143
The growth and development of rice (Oryzae sativa) seedlings was shown to be regulated epigenetically by a fungal endophyte. In contrast to un-inoculated (nonsymbiotic) plants, endophyte colonized (symbiotic) plants preferentially allocated resources into root growth until root hairs were well established. During that time symbiotic roots expanded at five times...
The role of reaction affinity and secondary minerals in regulating chemical weathering rates at the Santa Cruz Soil Chronosequence, California
K. Maher, Carl Steefel, A. F. White, David A. Stonestrom
2009, Geochimica et Cosmochimica Acta (73) 2804-2831
In order to explore the reasons for the apparent discrepancy between laboratory and field weathering rates and to determine the extent to which weathering rates are controlled by the approach to thermodynamic equilibrium, secondary mineral precipitation, and flow rates, a multicomponent reactive transport model (CrunchFlow) was used to interpret soil...
Summary of current radiometric calibration coefficients for Landsat MSS, TM, ETM+, and EO-1 ALI sensors
G. Chander, B. L. Markham, D. L. Helder
2009, Remote Sensing of Environment (113) 893-903
This paper provides a summary of the current equations and rescaling factors for converting calibrated Digital Numbers (DNs) to absolute units of at-sensor spectral radiance, Top-Of-Atmosphere (TOA) reflectance, and at-sensor brightness temperature. It tabulates the necessary constants for the Multispectral Scanner (MSS), Thematic Mapper (TM), Enhanced Thematic Mapper Plus (ETM+),...
Ultra-deep oxidation and exotic copper formation at the late pliocene boyongan and bayugo porphyry copper-gold deposits, surigao, philippines: Geology, mineralogy, paleoaltimetry, and their implications for Geologic, physiographic, and tectonic controls
D.P. Braxton, D. R. Cooke, A.M. Ignacio, R. O. Rye, P.J. Waters
2009, Economic Geology (104) 333-349
The Boyongan and Bayugo porphyry copper-gold deposits are part of an emerging belt of intrusion-centered gold-rich deposits in the Surigao district of northeast Mindanao, Philippines. Exhumation and weathering of these Late Pliocene-age deposits has led to the development of the world's deepest known porphyry oxidation profile at Boyongan (600 m),...
Using nitrogen stable isotopes to detect longdistance movement in a threatened cutthroat trout (Oncorhynchus clarkii utah)
A.J. Sepulveda, W.T. Colyer, W.H. Lowe, M.R. Vinson
2009, Canadian Journal of Fisheries and Aquatic Sciences (66) 672-682
Interior cutthroat trout occupy small fractions of their historic ranges and existing populations often are relegated to headwater habitats. Conservation requires balancing protection for isolated genetically pure populations with restoration of migratory life histories by reconnecting corridors between headwater and mainstem habitats. Identification of alternative life history strategies within a...
Numerical simulation of dune-flat bed transition and stage‐discharge relationship with hysteresis effect
Yasuyuki Shimizu, Sanjay Giri, Satomi Yamaguchi, Jonathan M. Nelson
2009, Water Resources Research (45)
This work presents recent advances on morphodynamic modeling of bed forms under unsteady discharge. This paper includes further development of a morphodynamic model proposed earlier by Giri and Shimizu (2006a). This model reproduces the temporal development of river dunes and accurately replicates the physical properties associated with bed form evolution....
Methylmercury enters an aquatic food web through acidophilic microbial mats in Yellowstone National Park, Wyoming
Eric S. Boyd, S. King, J.K. Tomberlin, D. Kirk Nordstrom, D. P. Krabbenhoft, T. Barkay, G. G. Geesey
2009, Environmental Microbiology (11) 950-959
Microbial mats are a visible and abundant life form inhabiting the extreme environments in Yellowstone National Park (YNP), WY, USA. Little is known of their role in food webs that exist in the Park's geothermal habitats. Eukaryotic green algae associated with a phototrophic green/purple Zygogonium microbial mat community that inhabits low-temperature regions...
Uptake rate constants and partition coefficients for vapor phase organic chemicals using semipermeable membrane devices (SPMDs)
W.L. Cranor, D.A. Alvarez, J.N. Huckins, J. D. Petty
2009, Atmospheric Environment (43) 3211-3219
To fully utilize semipermeable membrane devices (SPMDs) as passive samplers in air monitoring, data are required to accurately estimate airborne concentrations of environmental contaminants. Limited uptake rate constants (kua) and no SPMD air partitioning coefficient (Ksa) existed for vapor-phase contaminants. This research was conducted to expand the existing body of...
Food habits of the hoary bat (LASIURUS CINEREUS) during spring migration through new mexico
E.W. Valdez, P.M. Cryan
2009, Southwestern Naturalist (54) 195-200
Hoary bats (Lasiums cinernis) exhibit continental patterns of migration that are unique to bats, but details about their behaviors during migration are lacking. We captured 177 hoary bats in spring and early summer 2002 as individuals migrated through the Sandia Mountains of north-central New Mexico. Our results support earlier observations...
Brood rearing ecology of king eiders on the north slope of Alaska
Laura M. Phillips, Abby N. Powell
2009, Wilson Journal of Ornithology (121) 430-434
We examined King Eider (Somateria spectabilis) brood survival in the Kuparak oil field in northern Alaska in 2002 and 2003 by monitoring hens with broods using radiotelemetry. We observed complete brood loss in eight of 10 broods. Broods survived less than 2 weeks on average, and most mortality occurred within...
Nitrate removal in stream ecosystems measured by 15N addition experiments: Total uptake
R. O. Hall Jr., J. L. Tank, D. J. Sobota, P. J. Mulholland, J. M. O’Brien, W. K. Dodds, J.R. Webster, H. M. Valett, G. C. Poole, B. J. Peterson, J.L. Meyer, W. H. McDowell, S. L. Johnson, S. K. Hamilton, N. B. Grimm, S.V. Gregory, Clifford N. Dahm, L. W. Cooper, L. R. Ashkenas, S. M. Thomas, R.W. Sheibley, J. D. Potter, B.R. Niederlehner, L. T. Johnson, A. M. Helton, C.M. Crenshaw, A. J. Burgin, M. J. Bernot, J. J. Beaulieu, C.P. Arangob
2009, Limnology and Oceanography (54) 653-665
We measured uptake length of 15NO-3 in 72 streams in eight regions across the United States and Puerto Rico to develop quantitative predictive models on controls of NO-3 uptake length. As part of the Lotic Intersite Nitrogen eXperiment II project, we chose nine streams in each region corresponding to natural...
Use of OSL dating to establish the stratigraphic framework of Quaternary eolian sediments, Anton scarp upper trench, Northeastern Colorado High Plains, USA
S. A. Mahan, D.C. Noe, J.P. McCalpin
2009, Quaternary International (199) 92-103
This paper contains the results of the optically stimulated luminescence (OSL) dating used to establish stratigraphic ages and relationships of eolian sediments in a trench in northeastern Colorado, USA. This trench was located in the upper face of the Anton scarp, a major topographic lineament trending NW-SE for a distance...
Impacts of episodic acidification on in-stream survival and physiological impairment of Atlantic salmon (Salmo salar) smolts
S. D. McCormick, A. Keyes, K.H. Nislow, M.Y. Monette
2009, Canadian Journal of Fisheries and Aquatic Sciences (66) 394-403
We conducted field studies to determine the levels of acid and aluminum (Al) that affect survival, smolt development, ion homeostasis, and stress in Atlantic salmon (Salmo salar) smolts in restoration streams of the Connecticut River in southern Vermont, USA. Fish were held in cages in five streams encompassing a wide...
Recent experimental data may point to a greater role for osmotic pressures in the subsurface
C. E. Neuzil, A.M. Provost
2009, Water Resources Research (45)
Uncertainty about the origin of anomalous fluid pressures in certain geologic settings has caused researchers to take a second look at osmosis, or flow driven by chemical potential differences, as a pressure‐generating process in the subsurface. Interest in geological osmosis has also increased because of an in situ experiment by...
Nitrate removal in stream ecosystems measured by 15N addition experiments: Denitrification
P. J. Mulholland, R. O. Hall Jr., D. J. Sobota, W. K. Dodds, S.E.G. Findlay, N. B. Grimm, S. K. Hamilton, W. H. McDowell, J. M. O’Brien, J. L. Tank, L. R. Ashkenas, L. W. Cooper, Clifford N. Dahm, S.V. Gregory, S. L. Johnson, J.L. Meyer, B. J. Peterson, G. C. Poole, H. M. Valett, J.R. Webster, C. P. Arango, J. J. Beaulieu, M. J. Bernot, A. J. Burgin, C. L. Crenshaw, A. M. Helton, L. T. Johnson, B.R. Niederlehner, J. D. Potter, R.W. Sheibley, S.M. Thomasn
2009, Limnology and Oceanography (54) 666-680
We measured denitrification rates using a field 15N-NO- 3 tracer-addition approach in a large, cross-site study of nitrate uptake in reference, agricultural, and suburban-urban streams. We measured denitrification rates in 49 of 72 streams studied. Uptake length due to denitrification (SWden) ranged from 89 m to 184 km (median of...
Concentrations of cadmium, Cobalt, Lead, Nickel, and Zinc in Blood and Fillets of Northern Hog Sucker (Hypentelium nigricans) from streams contaminated by lead-Zinc mining: Implications for monitoring
C. J. Schmitt, W. G. Brumbaugh, T.W. May
2009, Archives of Environmental Contamination and Toxicology (56) 509-524
Lead (Pb) and other metals can accumulate in northern hog sucker (Hypentelium nigricans) and other suckers (Catostomidae), which are harvested in large numbers from Ozark streams by recreational fishers. Suckers are also important in the diets of piscivorous wildlife and fishes. Suckers from streams contaminated by historic Pb-zinc (Zn) mining...
Estimating the encounter rate variance in distance sampling
R.M. Fewster, S.T. Buckland, K.P. Burnham, D.L. Borchers, P.E. Jupp, J.L. Laake, L. Thomas
2009, Biometrics (65) 225-236
The dominant source of variance in line transect sampling is usually the encounter rate variance. Systematic survey designs are often used to reduce the true variability among different realizations of the design, but estimating the variance is difficult and estimators typically approximate the variance by treating the design as a...
Methane sources in gas hydrate-bearing cold seeps: Evidence from radiocarbon and stable isotopes
J. W. Pohlman, J.E. Bauer, E. A. Canuel, K.S. Grabowski, D.L. Knies, C.S. Mitchell, Michael J. Whiticar, R.B. Coffin
2009, Marine Chemistry (115) 102-109
Fossil methane from the large and dynamic marine gas hydrate reservoir has the potential to influence oceanic and atmospheric carbon pools. However, natural radiocarbon (14C) measurements of gas hydrate methane have been extremely limited, and their use as a source and process indicator has not yet been systematically established. In...
Historical and modern disturbance regimes, stand structures, and landscape dynamics in piñon-juniper vegetation of the western United States
William H. Romme, Craig D. Allen, John D. Bailey, William L. Baker, Brandon T. Bestelmeyer, Peter M. Brown, Karen S. Eisenhart, M. Lisa Floyd, David W. Huffman, Brian F. Jacobs, Richard F. Miller, Esteban H. Muldavin, Thomas W. Swetnam, Robin J. Tausch, Peter J. Weisberg
2009, Rangeland Ecology and Management (62) 203-222
Piñon–juniper is a major vegetation type in western North America. Effective management of these ecosystems has been hindered by inadequate understanding of 1) the variability in ecosystem structure and ecological processes that exists among the diverse combinations of piñons, junipers, and associated shrubs, herbs, and soil organisms; 2) the prehistoric...
A distal earthquake cluster concurrent with the 2006 explosive eruption of Augustine Volcano, Alaska
M. A. Fisher, N.A. Ruppert, R.A. White, Frederic H. Wilson, D. Comer, R. W. Sliter, F. L. Wong
2009, Tectonophysics (469) 25-36
Clustered earthquakes located 25 km northeast of Augustine Volcano began about 6 months before and ceased soon after the volcano's 2006 explosive eruption. This distal seismicity formed a dense cluster less than 5 km across, in map view, and located in depth between 11 km and 16 km. This seismicity was contemporaneous with sharply increased...
Thorium abundances on the Aristarchus plateau: Insights into the composition of the Aristarchus pyroclastic glass deposits
Justin Hagerty, D. J. Lawrence, B. R. Hawke, Lisa R. Gaddis
2009, Journal of Geophysical Research E: Planets (114)
Thorium (Th) data from the Lunar Prospector gamma ray spectrometer (LP‐GRS) are used to constrain the composition of lunar pyroclastic glass deposits on top of the Aristarchus plateau. Our goal is to use forward modeling of LP‐GRS Th data to measure the Th abundances on the plateau and then to...