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Page 1761, results 44001 - 44025

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Late Pleistocene glaciation of the Mt Giluwe volcano, Papua New Guinea
T.T. Barrows, G.S. Hope, M.L. Prentice, L.K. Fifield, S.G. Tims
2011, Quaternary Science Reviews (30) 2676-2689
The Mt Giluwe shield volcano was the largest area glaciated in Papua New Guinea during the Pleistocene. Despite minimal cooling of the sea surface during the last glacial maximum, glaciers reached elevations as low as 3200 m. To investigate changes in the extent of ice through time we have re-mapped evidence...
Feasibility of waveform inversion of Rayleigh waves for shallow shear-wave velocity using a genetic algorithm
C. Zeng, J. Xia, R. D. Miller, G.P. Tsoflias
2011, Journal of Applied Geophysics (75) 648-655
Conventional surface wave inversion for shallow shear (S)-wave velocity relies on the generation of dispersion curves of Rayleigh waves. This constrains the method to only laterally homogeneous (or very smooth laterally heterogeneous) earth models. Waveform inversion directly fits waveforms on seismograms, hence, does not have such a limitation. Waveforms of...
Divergence in forest-type response to climate and weather: Evidence for regional links between forest-type evenness and net primary productivity
J.B. Bradford
2011, Ecosystems (14) 975-986
Climate change is altering long-term climatic conditions and increasing the magnitude of weather fluctuations. Assessing the consequences of these changes for terrestrial ecosystems requires understanding how different vegetation types respond to climate and weather. This study examined 20 years of regional-scale remotely sensed net primary productivity (NPP) in forests of the...
Sphaeridiotrema globulus and Sphaeridiotrema pseudoglobulus (Digenea): Species differentiation based on mtDNA (Barcode) and partial LSUrDNA sequences
L. Bergmame, J. Huffman, Rebecca A. Cole, S. Dayanandan, V. Tkach, J.D. McLaughlin
2011, Journal of Parasitology (97) 1132-1136
Flukes belonging to Sphaeridiotrema are important parasites of waterfowl, and 2 morphologically similar species Sphaeridiotrema globulus and Sphaeridiotrema pseudoglobulus, have been implicated in waterfowl mortality in North America. Cytochrome oxidase I (barcode region) and partial LSU-rDNA sequences from specimens of S. globulus and S. pseudoglobulus, obtained from naturally and experimentally infected hosts from...
Multimodel inference and adaptive management
S.E. Rehme, L.A. Powell, Craig R. Allen
2011, Journal of Environmental Management (92) 1360-1364
Ecology is an inherently complex science coping with correlated variables, nonlinear interactions and multiple scales of pattern and process, making it difficult for experiments to result in clear, strong inference. Natural resource managers, policy makers, and stakeholders rely on science to provide timely and accurate management recommendations. However, the time...
Using a semi-natural stream to produce young sturgeons for conservation stocking: Maintaining natural selection during spawning and rearing
B. Kynard, D. Pugh, T. Parker, Micah Kieffer
2011, Journal of Applied Ichthyology (27) 420-424
Young sturgeons used for conservation stocking are presently produced using the same methods used for commercial culture. To determine if young sturgeons could be produced without relaxing natural selection factors, we developed a semi‐natural stream where we annually studied mating of wild shortnose sturgeon (Acipenser brevirostrum) observed movement of gametes...
Landscape evolution in south-central Minnesota and the role of geomorphic history on modern erosional processes
K.B. Gran, P. Belmont, S.S. Day, N. Finnegan, C. Jennings, J.W. Lauer, P.R. Wilcock
2011, Conference Paper, GSA Today
The Minnesota River Valley was carved during catastrophic drainage of glacial Lake Agassiz at the end of the late Pleistocene. The ensuing base-level drop on tributaries created knickpoints that excavated deep valleys as they migrated upstream. A sediment budget compiled in one of these tributaries, the Le Sueur River, shows...
Behavioral and physiological responses to male handicap in chick-rearing black-legged kittiwakes
S. Leclaire, V. Bourret, R.H. Wagner, Scott A. Hatch, F. Helfenstein, O. Chastel, E. Danchin
2011, Behavioral Ecology (22) 1156-1165
Parental investment entails a trade-off between the benefits of effort in current offspring and the costs to future reproduction. Long-lived species are predicted to be reluctant to increase parental effort to avoid affecting their survival. We tested this hypothesis in black-legged kittiwakes Rissa tridactyla by clipping flight feathers of experimental males at...
Seasonal distribution of Gulf of Mexico sturgeon in the pensacola bay system, Florida
M.S. Duncan, B.M. Wrege, Frank M. Parauka, J. Jeffery Isely
2011, Journal of Applied Ichthyology (27) 316-321
Temporal and spatial distributions of Gulf of Mexico (Gulf) sturgeon Acipenser oxyrinchus desotoi were assessed in the Pensacola bay system, Florida, using stationary ultrasonic telemetry. Fifty‐eight Gulf sturgeon were tagged within the Escambia (n = 26), Yellow (n = 8), Blackwater (n = 12) and Choctawhatchee Rivers (n = 12) in June, July, September and October, 2005. Fifty‐four Gulf sturgeon...
Compositional diversity and geologic insights of the Aristarchus crater from Moon Mineralogy Mapper data
J.F. Mustard, C.M. Pieters, P.J. Isaacson, J.W. Head, S. Besse, R. N. Clark, R.L. Klima, N.E. Petro, M.I. Staid, J.M. Sunshine, C.J. Runyon, S. Tompkins
2011, Journal of Geophysical Research E: Planets (116)
The Moon Mineralogy Mapper (M3) acquired high spatial and spectral resolution data of the Aristarchus Plateau with 140 m/pixel in 85 spectral bands from 0.43 to 3.0 m. The data were collected as radiance and converted to reflectance using the observational constraints and a solar spectrum scaled to the Moon-Sun...
Surface complexation modeling for predicting solid phase arsenic concentrations in the sediments of the Mississippi River Valley alluvial aquifer, Arkansas, USA
M.S.U. Sharif, R.K. Davis, K.F. Steele, B. Kim, P.D. Hays, T.M. Kresse, J.A. Fazio
2011, Applied Geochemistry (26) 496-504
The potential health impact of As in drinking water supply systems in the Mississippi River Valley alluvial aquifer in the state of Arkansas, USA is significant. In this context it is important to understand the occurrence, distribution and mobilization of As in the Mississippi River Valley alluvial aquifer. Application of...
The efficacy of salvage logging in reducing subsequent fire severity in conifer-dominated forests of Minnesota, USA
S. Fraver, T. Jain, J.B. Bradford, A.W. D’Amato, D. Kastendick, B. Palik, D. Shinneman, J. Stanovick
2011, Ecological Applications (21) 1895-1901
Although primarily used to mitigate economic losses following disturbance, salvage logging has also been justified on the basis of reducing fire risk and fire severity; however, its ability to achieve these secondary objectives remains unclear. The patchiness resulting from a sequence of recent disturbances—blowdown, salvage logging, and wildfire—provided an excellent...
Late Holocene slip rate of the San Andreas fault and its accommodation by creep and moderate-magnitude earthquakes at Parkfield, California
N.A. Toke, J.R. Arrowsmith, Michael J. Rymer, A. Landgraf, D.E. Haddad, M. Busch, J. Coyan, A. Hannah
2011, Geology (39) 243-246
Investigation of a right-laterally offset channel at the Miller's Field paleoseismic site yields a late Holocene slip rate of 26.2 +6.4/−4.3 mm/yr (1σ) for the main trace of the San Andreas fault at Parkfield, California. This is the first well-documented geologic slip rate between the Carrizo and creeping sections of...
Identifying nest predators of American avocets (Recurvirostra americana) and black-necked stilts (Himantopus mexicanus) in San Francisco Bay, California
G. Herring, Joshua T. Ackerman, John Y. Takekawa, Collin A. Eagles-Smith, J.M. Eadie
2011, Southwestern Naturalist (56) 35-43
We evaluated predation on nests and methods to detect predators using a combination of infrared cameras and plasticine eggs at nests of American avocets (Recurvirostra americana) and black-necked stilts (Himantopus mexicanus) in Don Edwards San Francisco Bay National Wildlife Refuge, San Mateo and Santa Clara counties, California. Each...
The dynamical core, physical parameterizations, and basic simulation characteristics of the atmospheric component AM3 of the GFDL global coupled model CM3
L.J. Donner, B.L. Wyman, R.S. Hemler, L.W. Horowitz, Y. Ming, M. Zhao, J.-C. Golaz, P. Ginoux, S.-J. Lin, M.D. Schwarzkopf, J. Austin, G. Alaka, W.F. Cooke, T.L. Delworth, S.M. Freidenreich, C.T. Gordon, S.M. Griffies, I.M. Held, W.J. Hurlin, S.A. Klein, T.R. Knutson, A.R. Langenhorst, H.-C. Lee, Y. Lin, B.I. Magi, S.L. Malyshev, Paul Milly, V. Naik, M.J. Nath, R. Pincus, J.J. Ploshay, V. Ramaswamy, C.J. Seman, E. Shevliakova, J.J. Sirutis, W.F. Stern, R.J. Stouffer, R.J. Wilson, M. Winton, A.T. Wittenberg, F. Zeng
2011, Journal of Climate (24) 3484-3519
The Geophysical Fluid Dynamics Laboratory (GFDL) has developed a coupled general circulation model (CM3) for the atmosphere, oceans, land, and sea ice. The goal of CM3 is to address emerging issues in climate change, including aerosol–cloud interactions, chemistry–climate interactions, and coupling between the troposphere and stratosphere. The model is also...
2-D inner-shelf current observations from a single VHF WEllen RAdar (WERA) station
G. Voulgaris, N. Kumar, K.-W. Gurgel, John C. Warner, Jeffrey H. List
2011, Conference Paper, 2011 IEEE/OES/CWTM 10th working conference on current, waves and turbulence measurement, CWTM 2011
The majority of High Frequency (HF) radars used worldwide operate at medium to high frequencies (8 to 30 MHz) providing spatial resolutions ranging from 3 to 1.5 km and ranges from 150 to 50 km. This paper presents results from the deployment of a single Very High Frequency (VHF, 48...
Multiplets: Their behavior and utility at dacitic and andesitic volcanic centers
W. Thelen, S. Malone, M. West
2011, Journal of Geophysical Research B: Solid Earth (116)
Multiplets, or groups of earthquakes with similar waveforms, are commonly observed at volcanoes, particularly those exhibiting unrest. Using triggered seismic data from the 1980-1986 Mount St. Helens (MSH) eruption, we have constructed a catalog of multiplet occurrence. Our analysis reveals that the occurrence of multiplets is related, at least in...
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...
Whole-edifice ice volume change A.D. 1970 to 2007/2008 at Mount Rainier, Washington, based on LiDAR surveying
T. W. Sisson, J.E. Robinson, D.D. Swinney
2011, Geology (39) 639-642
Net changes in thickness and volume of glacial ice and perennial snow at Mount Rainier, Washington State, have been mapped over the entire edifice by differencing between a highresolution LiDAR (light detection and ranging) topographic survey of September-October 2007/2008 and the 10 m lateral resolution U.S. Geological Survey digital elevation...
Interactions between natural-occurring landscape conditions and land use influencing the abundance of riverine smallmouth bass, micropterus dolomieu
S.K. Brewer, C.F. Rabeni
2011, Canadian Journal of Fisheries and Aquatic Sciences (68) 1922-1933
This study examined how interactions between natural landscape features and land use influenced the abundance of smallmouth bass, Micropterus dolomieu, in Missouri, USA, streams. Stream segments were placed into one of four groups based on natural-occurring watershed characteristics (soil texture and soil permeability) predicted to relate to smallmouth bass abundance....
Position of the Triassic-Jurassic boundary and timing of the end-Triassic extinctions on land: Data from the Moenave Formation on the southern Colorado Plateau, USA
S. G. Lucas, L.H. Tanner, L. Donohoo-Hurley, J. W. Geissman, H. W. Kozur, A.B. Heckert, Robert E. Weems
2011, Palaeogeography, Palaeoclimatology, Palaeoecology (302) 194-205
Strata of the Moenave Formation on and adjacent to the southern Colorado Plateau in Utah–Arizona, U.S.A., represent one of the best known and most stratigraphically continuous, complete and fossiliferous terrestrial sections across the Triassic–Jurassic boundary. We present a synthesis of new biostratigraphic and magnetostratigraphic data collected from across the Moenave...
Changes in monoterpene mixing ratios during summer storms in rural New Hampshire (USA)
Karl B. Haase, C. Jordan, E. Mentis, L. Cottrell, H.R. Mayne, R. Talbot, B.C. Sive
2011, Atmospheric Chemistry and Physics Discussions (11) 20631-20665
Monoterpenes are an important class of biogenic hydrocarbons that influence ambient air quality and are a principle source of secondary organic aerosol (SOA). Emitted from vegetation, monoterpenes are a product of photosynthesis and act as a response to a variety of environmental factors. Most parameterizations of monoterpene emissions are based...
Assessment of clinical pathology and pathogen exposure in sea otters (Enhydra lutris) bordering the threatened population in Alaska
Tracey Goldstein, Verena A. Gill, Pamela A. Tuomi, Daniel H. Monson, Alexander Burdin, Patricia A. Conrad, J. Lawrence Dunn, Cara L. Field, Christine K. Johnson, David A. Jessup, James L. Bodkin, Angela M. Doroff
2011, Journal of Wildlife Diseases (47) 579-592
Northern sea otter (Enhydra lutris kenyoni) abundance has decreased dramatically over portions of southwest Alaska, USA, since the mid-1980s, and this stock is currently listed as threatened under the Endangered Species Act. In contrast, adjacent populations in south central Alaska, USA, and Russia have been stable to increasing during the...
Aeolian nutrient fluxes following wildfire in sagebrush steppe: Implications for soil carbon storage
N.J. Hasselquist, M.J. Germino, Joel B. Sankey, L.J. Ingram, N.F. Glenn
2011, Biogeosciences Discussions (8) 8323-8349
. Pulses of aeolian transport following fire can profoundly affect the biogeochemical cycling of nutrients in semi-arid and arid ecosystems. Our objective was to determine horizontal nutrient fluxes occurring in the saltation zone during an episodic pulse of aeolian transport that occurred following a wildfire in a semi-arid sagebrush steppe...
A bacterium that can grow by using arsenic instead of phosphorus
Felisa Wolfe-Simon, Jodi S. Blum, T.R. Kulp, Gordon W. Rattray, S.E. Hoeft, J. Pett-Ridge, J.F. Stolz, S.M. Webb, P.K. Weber, P.C.W. Davies, A.D. Anbar, R.S. Oremland
2011, Science (332) 1163-1166
Life is mostly composed of the elements carbon, hydrogen, nitrogen, oxygen, sulfur, and phosphorus. Although these six elements make up nucleic acids, proteins, and lipids and thus the bulk of living matter, it is theoretically possible that some other elements in the periodic table could serve the same functions. Here,...