Skip to main content
U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Results

69061 results.

Alternate formats: RIS file of the first 3000 search results  |  Download all results as CSV | TSV | Excel  |  RSS feed based on this search  |  JSON version of this page of results

Page 699, results 17451 - 17475

Show results on a map

Publication Extents

Not all publications have extents, not all extents are completely accurate
Ecological controls on the shell geochemistry of pink and white Globigerinoides ruber in the northern Gulf of Mexico: implications for paleoceanographic reconstruction
Julie N. Richey, Richard Z. Poore, Benjamin P. Flower, David J. Hollander
2012, Marine Micropaleontology (82-83) 28-37
We evaluate the relationship between foraminiferal test size and shell geochemistry (δ13C, δ18O, and Mg/Ca) for two of the most commonly used planktonic foraminifers for paleoceanographic reconstruction in the subtropical Atlantic Ocean: the pink and white varieties of Globigerinoides ruber. Geochemical analyses were performed on foraminifera from modern core-top samples...
Assessment of pingo distribution and morphometry using an IfSAR derived digital surface model, western Arctic Coastal Plain, Northern Alaska
Benjamin M. Jones, G. Grosse, Kenneth M. Hinkel, C.D. Arp, S. Walker, R.A. Beck, J. P. Galloway
2012, Geomorphology (138) 1-14
Pingos are circular to elongate ice-cored mounds that form by injection and freezing of pressurized water in near-surface permafrost. Here we use a digital surface model (DSM) derived from an airborne Interferometric Synthetic Aperture Radar (IfSAR) system to assess the distribution and morphometry of pingos within a 40,000 km2 area on the...
Determination of sediment provenance by unmixing the mineralogy of source-area sediments: The "SedUnMix" program
John T. Andrews, D. D. Eberl
2012, Marine Geology (291-294) 24-33
Along the margins of areas such as Greenland and Baffin Bay, sediment composition reflects a complex mixture of sources associated with the transport of sediment in sea ice, icebergs, melt-water and turbidite plumes. Similar situations arise in many contexts associated with sediment transport and with the mixing of sediments from...
Water utilization of the Cretaceous Mussentuchit Member local vertebrate fauna, Cedar Mountain Formation, Utah, USA: Using oxygen isotopic composition of phosphate
C.A. Suarez, Luis A. Gonzalez, G.A. Ludvigson, R.L. Cifelli, E. Tremain
2012, Palaeogeography, Palaeoclimatology, Palaeoecology (313-314) 78-92
While the oxygen isotopic composition of pedogenic carbonate has successfully been used to address the effects of global climate change on the hydrologic cycle, detailed regional paleohydrologic studies are lacking. Since the hydrologic cycle can vary extensively on local or regional scales due to events such as such as...
Geochemical constraints on adakites of different origins and copper mineralization
W.-D. Sun, M.-X. Ling, S.-L. Chung, X. Ding, X.-Y. Yang, H.-Y. Liang, W.-M. Fan, R. Goldfarb, Q.-Z. Yin
2012, Journal of Geology (120) 105-120
The petrogenesis of adakites holds important clues to the formation of the continental crust and copper ± gold porphyry mineralization. However, it remains highly debated as to whether adakites form by slab melting, by partial melting of the lower continental crust, or by fractional crystallization of normal arc magmas. Here,...
Hydrological effects of the increased CO2 and climate change in the Upper Mississippi River Basin using a modified SWAT
Y. Wu, S. Liu, O. I. Abdul-Aziz
2012, Climatic Change (110) 977-1003
Increased atmospheric CO2 concentration and climate change may significantly impact the hydrological and meteorological processes of a watershed system. Quantifying and understanding hydrological responses to elevated ambient CO2 and climate change is, therefore, critical for formulating adaptive strategies for an appropriate management of water resources. In this study, the Soil...
Presence of avian influenza viruses in waterfowl and wetlands during summer 2010 in California: Are resident birds a potential reservoir?
V. Henaux, M.D. Samuel, Robert J. Dusek, J. P. Fleskes, Hon S. Ip
2012, PLoS ONE (7)
Although wild waterfowl are the main reservoir for low pathogenic avian influenza viruses (LPAIv), the environment plays a critical role for the circulation and persistence of AIv. LPAIv may persist for extended periods in cold environments, suggesting that waterfowl breeding areas in the northern hemisphere may be an important reservoir...
Photodissolution of soil organic matter
L.M. Mayer, K.R. Thornton, L.L. Schick, J.D. Jastrow, Jennifer W. Harden
2012, Geoderma (170) 314-321
Sunlight has been shown to enhance loss of organic matter from aquatic sediments and terrestrial plant litter, so we tested for similar reactions in mineral soil horizons. Losses of up to a third of particulate organic carbon occurred after continuous exposure to full-strength sunlight for dozens of hours, with similar...
Isotopically modified nanoparticles for enhanced detection in bioaccumulation studies
S.K. Misra, A. Dybowska, D. Berhanu, Marie Noele Croteau, Samuel N. Luoma, A.R. Boccaccini, E. Valsami-Jones
2012, Environmental Science & Technology (46) 1216-1222
This work presents results on synthesis of isotopically enriched (99% 65Cu) copper oxide nanoparticles and its application in ecotoxicological studies. 65CuO nanoparticles were synthesized as spheres (7 nm) and rods (7 × 40 nm). Significant differences were observed between the reactivity and dissolution of spherical and rod shaped nanoparticles. The extreme sensitivity...
Concentration, distribution, and translocation of mercury and methylmercury in mine-waste, sediment, soil, water, and fish collected near the Abbadia San Salvatore mercury mine, Monte Amiata district, Italy
V. Rimondi, J. E. Gray, P. Costagliola, O. Vaselli, P. Lattanzi
2012, Science of the Total Environment (414) 318-327
The distribution and translocation of mercury (Hg) was studied in the Paglia River ecosystem, located downstream from the inactive Abbadia San Salvatore mine (ASSM). The ASSM is part of the Monte Amiata Hg district, Southern Tuscany, Italy, which was one of the world’s largest Hg districts. Concentrations of Hg and...
Seasonal habitat use and selection by grizzly bears in Northern British Columbia
B. Milakovic, K.L. Parker, D.D. Gustine, R.J. Lay, A.B.D. Walker, M.P. Gillingham
2012, Journal of Wildlife Management (76) 170-180
We defined patterns of habitat use and selection by female grizzly bears (Ursus arctos) in the Besa-Prophet watershed of northern British Columbia. We fitted 13 adult females with Geographic Positioning System (GPS) radio-collars and monitored them between 2001 and 2004. We examined patterns of habitat selection by grizzly bears relative...
Correlation of early Paleogene global diversity patterns of large benthic foraminifera with Paleocene-Eocene hyperthermal events
Katherine J. Whidden, Robert J. Jones
2012, Palaios (27) 235-251
Large benthic foraminifera (LBF) were major contributors to many Paleogene carbonate platforms around the world. These photosymbiotic foraminifera lived in warm, oligotrophic, shallow waters within the photic zone. Such Paleogene families as the nummulitids, alveolinids, and orthophragminids rose to prominence in the late Paleocene, thrived in the early and middle...
Expert knowledge as a foundation for the management of secretive species and their habitat
C. Ashton Drew, Jaime Collazo
2012, Book chapter, Expert knowledge and its application in landscape ecology
In this chapter, we share lessons learned during the elicitation and application of expert knowledge in the form of a belief network model for the habitat of a waterbird, the King Rail (Rallus elegans). A belief network is a statistical framework used to graphically represent and evaluate hypothesized...
Evidence for earthquake triggering of large landslides in coastal Oregon, USA
W.H. Schulz, S.L. Galloway, J.D. Higgins
2012, Geomorphology (141-142) 88-98
Landslides are ubiquitous along the Oregon coast. Many are large, deep slides in sedimentary rock and are dormant or active only during the rainy season. Morphology, observed movement rates, and total movement suggest that many are at least several hundreds of years old. The offshore Cascadia subduction zone produces great...
An application and extension of the constraints–effects–mitigation model to Minnesota waterfowl hunting
Susan A. Schroeder, David C. Fulton, Jeffrey S. Lawrence, Steven D. Cordts
2012, Human Dimensions of Wildlife (17) 174-192
This study extends modeling work on the leisure constraint negotiation process from physically active leisure and celebrity fandom to hunting. We test a model derived from the constraints–effects–mitigation model of leisure participation. The model is examined in the context of continued Minnesota waterfowl hunting among a sample of Minnesota residents...
Habitat and prey availability attributes associated with juvenile and early adult pallid sturgeon occurrence in the Missouri River, USA
Bryan D. Spindler, Steven R. Chipps, Robert A. Klumb, Brian D. S. Graeb, Michael C. Wimberly
2012, Endangered Species Research (16) 225-234
The pallid sturgeon Scaphirhynchus albus is a federally endangered species native to the Missouri and lower Mississippi Rivers, USA. As part of recovery efforts, over 360000 pallid sturgeon have been stocked into the Missouri River since 1994, and a standardized, long-term monitoring program was initiated in 2003. Understanding the distribution...
Stable water isotopologue ratios in fog and cloud droplets of liquid clouds are not size-dependent
J.K. Spiegel, F. Aemisegger, M. Scholl, F.G. Wienhold, J.L. Collett Jr., T. Lee, D. van Pinxteren, S. Mertes, A. Tilgner, H. Herrmann, Roland A. Werner, N. Buchmann, W. Eugster
2012, Atmospheric Chemistry and Physics (12) 9855-9863
In this work, we present the first observations of stable water isotopologue ratios in cloud droplets of different sizes collected simultaneously. We address the question whether the isotope ratio of droplets in a liquid cloud varies as a function of droplet size. Samples were collected from a ground intercepted cloud...
Modeling of land use and reservoir effects on nonpoint source pollution in a highly agricultural basin
Yiping Wu, Shu-Guang Liu
2012, Journal of Environmental Monitoring (14) 2350-2361
Nonpoint source (NPS) pollution is tightly linked to land use activities that determine the sources and magnitudes of pollutant loadings to stream water. The pollutant loads may also be alleviated within reservoirs because of the physical interception resulting from changed hydrological regimes and other biochemical processes. It is important but...
Spatial pattern formation of coastal vegetation in response to external gradients and positive feedbacks affecting soil porewater salinity: A model study
J. Jiang, Donald L. DeAngelis, T. J. Smith III, S.Y. Teh, H. L. Koh
2012, Landscape Ecology (27) 109-119
Coastal vegetation of South Florida typically comprises salinity-tolerant mangroves bordering salinity-intolerant hardwood hammocks and fresh water marshes. Two primary ecological factors appear to influence the maintenance of mangrove/hammock ecotones against changes that might occur due to disturbances. One of these is a gradient in one or more environmental factors. The...
Molecular characterization and comparison of shale oils generated by different pyrolysis methods
Justin E. Birdwell, Jang Mi Jin, Sunghwan Kim
2012, Energy & Fuels (26)
Shale oils generated using different laboratory pyrolysis methods have been studied using standard oil characterization methods as well as Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with electrospray ionization (ESI) and atmospheric photoionization (APPI) to assess differences in molecular composition. The pyrolysis oils were generated from samples of...
The influence of wave energy and sediment transport on seagrass distribution
Andrew W. Stevens, Jessica R. Lacy
2012, Estuaries and Coasts (35) 92-108
A coupled hydrodynamic and sediment transport model (Delft3D) was used to simulate the water levels, waves, and currents associated with a seagrass (Zostera marina) landscape along a 4-km stretch of coast in Puget Sound, WA, USA. A hydroacoustic survey of seagrass percent cover and nearshore bathymetry was conducted, and...
Community-level response of fishes and aquatic macroinvertebrates to stream restoration in a third-order tributary of the Potomac River, USA
S.M. Selego, C.L. Rose, G.T. Merovich Jr., Stuart A. Welsh, James T. Anderson
2012, International Journal of Ecology (2012)
Natural stream channel design principles and riparian restoration practices were applied during spring 2010 to an agriculturally impaired reach of the Cacapon River, a tributary of the Potomac River which flows into the Chesapeake Bay. Aquatic macroinvertebrates and fishes were sampled from the restoration reach, two degraded control, and two...
Climate change and human health: Spatial modeling of water availability, malnutrition, and livelihoods in Mali, Africa
Marta M. Jankowska, David Lopez-Carr, Chris Funk, Gregory J. Husak, Z.A. Chafe
2012, Applied Geography (33) 4-15
This study develops a novel approach for projecting climate trends in the Sahel in relation to shifting livelihood zones and health outcomes. Focusing on Mali, we explore baseline relationships between temperature, precipitation, livelihood, and malnutrition in 407 Demographic and Health Survey (DHS) clusters with a total of 14,238 children, resulting...
Results of the first North American comparison of absolute gravimeters, NACAG-2010
David Schmerge, Olvier Francis, J. Henton, D. Ingles, D. Jones, Jeffrey R. Kennedy, K. Krauterbluth, J. Liard, D. Newell, R. Sands, J. Schiel, J. Silliker, D. van Westrum
2012, Journal of Geodesy (86) 591-596
The first North American Comparison of absolute gravimeters (NACAG-2010) was hosted by the National Oceanic and Atmospheric Administration at its newly renovated Table Mountain Geophysical Observatory (TMGO) north of Boulder, Colorado, in October 2010. NACAG-2010 and the renovation of TMGO are part of NGS’s GRAV-D project (Gravity for the Redefinition...