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Page 1764, results 44076 - 44100

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Publication Extents

Not all publications have extents, not all extents are completely accurate
Patterns of coral disease across the Hawaiian Archipelago: Relating disease to environment
G.S. Aeby, G.J. Williams, E.C. Franklin, J. Kenyon, E.F. Cox, S. Coles, Thierry M. Work
2011, PLoS ONE (6)
In Hawaii, coral reefs occur across a gradient of biological (host abundance), climatic (sea surface temperature anomalies) and anthropogenic conditions from the human-impacted reefs of the main Hawaiian Islands (MHI) to the pristine reefs of the northwestern Hawaiian Islands (NWHI). Coral disease surveys were conducted at 142 sites from across...
High-resolution three-dimensional imaging and analysis of rock falls in Yosemite valley, California
Gregory M. Stock, Gerald W. Bawden, J.K. Green, E. Hanson, G. Downing, Brian D. Collins, Sandra Bond, M. Leslar
2011, Geosphere (7) 573-581
We present quantitative analyses of recent large rock falls in Yosemite Valley, California, using integrated high-resolution imaging techniques. Rock falls commonly occur from the glacially sculpted granitic walls of Yosemite Valley, modifying this iconic landscape but also posing significant potential hazards and risks. Two large rock falls occurred from the...
Potential misuse of avian density as a conservation metric
Susan K. Skagen, Amy A. Yackel Adams
2011, Conservation Biology (25) 48-55
: Effective conservation metrics are needed to evaluate the success of management in a rapidly changing world. Reproductive rates and densities of breeding birds (as a surrogate for reproductive rate) have been used to indicate the quality of avian breeding habitat, but the underlying assumptions of these metrics rarely have...
A first look at the petroleum geology of the Lomonosov Ridge microcontinent, Arctic Ocean
Thomas E. Moore, Arthur Grantz, Janet K. Pitman, Philip J. Brown
2011, Geological Society Memoir (35) 751-769
The Lomonosov microcontinent is an elongated continental fragment that transects the Arctic Ocean between North America and Siberia via the North Pole. Although it lies beneath polar pack ice, the geological framework of the microcontinent is inferred from sparse seismic reflection data, a few cores, potential field data and the...
Biogeochemistry of a temperate forest nitrogen gradient
Steven S. Perakis, Emily R. Sinkhorn
2011, Ecology (92) 1481-1491
Wide natural gradients of soil nitrogen (N) can be used to examine fundamental relationships between plant–soil–microbial N cycling and hydrologic N loss, and to test N-saturation theory as a general framework for understanding ecosystem N dynamics. We characterized plant production, N uptake and return in litterfall, soil gross and net...
Mapping permeability over the surface of the Earth
T. Gleeson, L. Smith, N. Moosdorf, J. Hartmann, H.H. Durr, Andrew H. Manning, L. P. H. Van Beek, A. Mark Jellinek
2011, Geophysical Research Letters (38)
Permeability, the ease of fluid flow through porous rocks and soils, is a fundamental but often poorly quantified component in the analysis of regional‐scale water fluxes. Permeability is difficult to quantify because it varies over more than 13 orders of magnitude and is heterogeneous and dependent on flow direction. Indeed,...
Management intensity alters decomposition via biological pathways
Kyle Wickings, A. Stuart Grandy, Sasha Reed, Cory Cleveland
2011, Biogeochemistry (104) 365-379
Current conceptual models predict that changes in plant litter chemistry during decomposition are primarily regulated by both initial litter chemistry and the stage-or extent-of mass loss. Far less is known about how variations in decomposer community structure (e.g., resulting from different ecosystem management types) could influence litter chemistry during decomposition....
When a habitat freezes solid: Microorganisms over-winter within the ice column of a coastal Antarctic lake
C.M. Foreman, M. Dieser, M. Greenwood, R.M. Cory, J. Laybourn-Parry, John T. Lisle, C. Jaros, P.L. Miller, Y.-P. Chin, Diane M. McKnight
2011, FEMS Microbiology Ecology (76) 401-412
A major impediment to understanding the biology of microorganisms inhabiting Antarctic environments is the logistical constraint of conducting field work primarily during the summer season. However, organisms that persist throughout the year encounter severe environmental changes between seasons. In an attempt to bridge this gap, we collected ice core samples...
The significance of turbulent flow representation in single-continuum models
Thomas Reimann, C. Rehrl, W.B. Shoemaker, T. Geyer, S. Birk
2011, Water Resources Research (47)
Karst aquifers exhibit highly conductive features caused from rock dissolution processes. Flow within these structures can become turbulent and therefore can be expressed by nonlinear gradient functions. One way to account for these effects is by coupling a continuum model with a conduit network. Alternatively, turbulent flow can be considered...
A hierarchical spatial framework and database for the national river fish habitat condition assessment
L. Wang, D. Infante, P. Esselman, A. Cooper, D. Wu, W. Taylor, D. Beard, G. Whelan, A. Ostroff
2011, Fisheries (36) 436-449
Fisheries management programs, such as the National Fish Habitat Action Plan (NFHAP), urgently need a nationwide spatial framework and database for health assessment and policy development to protect and improve riverine systems. To meet this need, we developed a spatial framework and database using National Hydrography Dataset Plus (I-.100,000-scale); http://www.horizon-systems.com/nhdplus)....
An occurrence of the protocetid whale "Eocetus" wardii in the middle Eocene Piney Point Formation of Virginia
Robert E. Weems, Lucy E. Edwards, Jason E. Osborne, A.A. Alford
2011, Journal of Paleontology (85) 271-278
Two protocetid whale vertebrae, here referred to “Eocetus” wardii, have been recovered from the riverbed of the Pamunkey River in east-central Virginia. Neither bone was found in situ, but both were found with lumps of lithified matrix cemented to their surfaces. Most of this matrix was removed and processed for...
Mapping the Philippines' mangrove forests using Landsat imagery
Jordan Long, Chandra Giri
2011, Sensors (11) 2972-2981
Current, accurate, and reliable information on the areal extent and spatial distribution of mangrove forests in the Philippines is limited. Previous estimates of mangrove extent do not illustrate the spatial distribution for the entire country. This study, part of a global assessment of mangrove dynamics, mapped the spatial distribution and...
Exploring the sensitivity of soil carbon dynamics to climate change, fire disturbance and permafrost thaw in a black spruce ecosystem
J. A. O'Donnell, Jennifer W. Harden, A. David McGuire, V.E. Romanovsky
2011, Biogeosciences (8) 1367-1382
In the boreal region, soil organic carbon (OC) dynamics are strongly governed by the interaction between wildfire and permafrost. Using a combination of field measurements, numerical modeling of soil thermal dynamics, and mass-balance modeling of OC dynamics, we tested the sensitivity of soil OC storage to a suite of individual...
Molecular insights into the biology of Greater Sage-Grouse
Sara J. Oyler-McCance, Thomas W. Quinn
2011, Book chapter, Greater Sage-Grouse: Ecology and conservation of a landscape species and its habitats
Recent research on Greater Sage-Grouse (Centrocercus urophasianus) genetics has revealed some important findings. First, multiple paternity in broods is more prevalent than previously thought, and leks do not comprise kin groups. Second, the Greater Sage-Grouse is genetically distinct from the congeneric Gunnison sage-grouse (C. minimus). Third, the Lyon-Mono population in...
Horizontal movements of Atlantic blue marlin (Makaira nigricans) in the Gulf of Mexico
Richard T. Kraus, R.J.D. Wells, J.R. Rooker
2011, Marine Biology (158) 699-713
We examined movements of Atlantic blue marlin (Makaira nigricans) from the Gulf of Mexico based upon 42 pop-up archival transmitting (PAT) tags. Long deployments (including one 334-day track) revealed diverse movement patterns within the Gulf of Mexico. North–south seasonal changes in blue marlin distribution showed strong correspondence with established seasonal...
Simulating adsorption of U(VI) under transient groundwater flow and hydrochemistry: Physical versus chemical nonequilibrium model
J. Greskowiak, M.B. Hay, H. Prommer, C. Liu, V.E.A. Post, R. Ma, J.A. Davis, C. Zheng, J.M. Zachara
2011, Water Resources Research (47)
Coupled intragrain diffusional mass transfer and nonlinear surface complexation processes play an important role in the transport behavior of U(VI) in contaminated aquifers. Two alternative model approaches for simulating these coupled processes were analyzed and compared: (1) the physical nonequilibrium approach that explicitly accounts for aqueous speciation and instantaneous surface...
Habitat fragmentation reduces nest survival in an Afrotropical bird community in a biodiversity hotspot
W.D. Newmark, T.R. Stanley
2011, Proceedings of the National Academy of Sciences of the United States of America (108) 11488-11493
Ecologists have long hypothesized that fragmentation of tropical landscapes reduces avian nest success. However, this hypothesis has not been rigorously assessed because of the difficulty of finding large numbers of well-hidden nests in tropical forests. Here we report that in the East Usambara Mountains in Tanzania, which are part of...
Impacts of Land-Cover Change on Suspended Sediment Transport in Two Agricultural Watersheds
K. E. Schilling, T.M. Isenhart, J.A. Palmer, C.F. Wolter, J. Spooner
2011, Journal of the American Water Resources Association (47) 672-686
Suspended sediment is a major water quality problem, yet few monitoring studies have been of sufficient scale and duration to assess the effectiveness of land-use change or conservation practice implementation at a watershed scale. Daily discharge and suspended sediment export from two 5,000-ha watersheds in central Iowa were monitored over...
Geology and petroleum potential of the Lincoln Sea Basin, offshore North Greenland
K. Sorensen, D. Gautier, Janet K. Pitman, H. Ruth Jackson, T. Dahl-Jensen
2011, Geological Society Memoir (35) 673-684
A seismic refraction line crossing the Lincoln Sea was acquired in 2006. It proves the existence of a deep sedimentary basin underlying the Lincoln Sea. This basin appears to be comparable in width and depth to the Sverdrup Basin of the Canadian Arctic Islands. The stratigraphy of the Lincoln Sea...
The dazed and confused identity of Agassiz's land tortoise, Gopherus agassizii (Testudines, Testudinidae) with the description of a new species, and its consequences for conservation
R. W. Murphy, K.H. Berry, T. Edwards, A.E. Leviton, A. Lathrop, J.D. Riedle
2011, ZooKeys (113) 39-41
We investigate a cornucopia of problems associated with the identity of the desert tortoise, Gopherus agassizii (Cooper). The date of publication is found to be 1861, rather than 1863. Only one of the three original cotypes exists, and it is designated as the lectotype of...
Demonstration of a conceptual model for using LiDAR to improve the estimation of floodwater mitigation potential of Prairie Pothole Region wetlands
S. Huang, Caitlin Young, M. Feng, Hans Karl Heidemann, Matthew Cushing, D.M. Mushet, S. Liu
2011, Journal of Hydrology (405) 417-426
Recent flood events in the Prairie Pothole Region of North America have stimulated interest in modeling water storage capacities of wetlands and their surrounding catchments to facilitate flood mitigation efforts. Accurate estimates of basin storage capacities have been hampered by a lack of high-resolution elevation data. In this paper, we...
The Augustine magmatic system as revealed by seismic tomography and relocated earthquake hypocenters from 1994 through 2009
E.M. Syracuse, C.H. Thurber, John A. Power
2011, Journal of Geophysical Research B: Solid Earth (116)
We incorporate 14 years of earthquake data from the Alaska Volcano Observatory with data from a 1975 controlled‐source seismic experiment to obtain the three‐dimensional P and S wave velocity structure and the first high‐precision earthquake locations at Augustine Volcano to be calculated in a fully three‐dimensional velocity model. Velocity tomography...
Reduction of structural Fe(III) in nontronite by methanogen Methanosarcina barkeri
D. Liu, Hailiang H. Dong, M.E. Bishop, Hongfang Wang, A. Agrawal, S. Tritschler, D. D. Eberl, S. Xie
2011, Geochimica et Cosmochimica Acta (75) 1057-1071
Clay minerals and methanogens are ubiquitous and co-exist in anoxic environments, yet it is unclear whether methanogens are able to reduce structural Fe(III) in clay minerals. In this study, the ability of methanogen Methanosarcina barkeri to reduce structural Fe(III) in iron-rich smectite (nontronite NAu-2) and the relationship between iron reduction and methanogenesis...
Groundwater chemistry near an impoundment for produced water, Powder River Basin, Wyoming, USA
R. W. Healy, T.T. Bartos, C. A. Rice, M.P. McKinley, B. D. Smith
2011, Journal of Hydrology (403) 37-48
The Powder River Basin is one of the largest producers of coal-bed natural gas (CBNG) in the United States. An important environmental concern in the Basin is the fate of the large amounts of groundwater extracted during CBNG production. Most of this produced water is disposed of in unlined surface...
Cytochrome P4501A biomarker indication of the timeline of chronic exposure of Barrow’s goldeneyes to residual Exxon Valdez oil
Daniel Esler, Brenda E. Ballachey, Kimberly A. Trust, Samuel A. Iverson, John A. Reed, A. Keith Miles, John D. Henderson, Bruce R. Woodin, John J. Stegeman, Malcolm McAdie, Daniel M. Mulcahy, Barry W. Wilson
2011, Marine Pollution Bulletin (62) 609-614
We examined hepatic EROD activity, as an indicator of CYP1A induction, in Barrow’s goldeneyes captured in areas oiled during the 1989 Exxon Valdez spill and those from nearby unoiled areas. We found that average EROD activity differed between areas during 2005, although the magnitude of the difference was reduced relative to a...