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The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
Browse more than 65,000 articles authored by our scientists over the past 100+ year history of the USGS and refine search by topic, location, year, and advanced search.
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The relative importance of mercury methylation and demethylation in rice paddy soil varies depending on the presence of rice plants The relative importance of mercury methylation and demethylation in rice paddy soil varies depending on the presence of rice plants
Neurotoxic methylmercury (MeHg) accumulates in rice grain from paddy soil, where its concentration is controlled by microbial mercury methylation and demethylation. Both up- and down-regulation of methylation is known to occur in the presence of rice plants in comparison to non-vegetated paddy soils; the influence of rice plant presence/absence on demethylation is unknown. To assess the...
Authors
R. J. Strickman, S. M. Larson, H. Huang, Evangelos Kakouros, Mark C. Marvin-DiPasquale, C. P. J. Mitchell, R. B. Neumann
Complete genome sequence of Rhodococcus opacus strain MoAcy1 (DSM 44186), an aerobic acetylenotroph isolated from soil Complete genome sequence of Rhodococcus opacus strain MoAcy1 (DSM 44186), an aerobic acetylenotroph isolated from soil
We report the genome of Rhodococcus opacus strain MoAcy1 (DSM 44186), an aerobic soil isolate capable of using acetylene as its primary carbon and energy source (acetylenotrophy). The genome is composed of a single circular chromosome of ∼8 Mbp and two closed plasmids, with a G+C content of 67.3%.
Authors
John M. Sutton, Timothy J. Bushman, Denise M. Akob, Janna L. Fierst
Introduction: Climate change in the mountains of Maine and the Northeast Introduction: Climate change in the mountains of Maine and the Northeast
No abstract available.
Authors
Sarah Nelson, Caitlin McDonough MacKenzie, Toni Lyn Morelli, Jay Wason, Bryan Wentzell, Rachel A. Hovel, Glenn A. Hodgkins, Abe J. Miller-Rushing, David Miller, Steve Tatko, Amanda Cross, Mike Pounch
Mesilla / Conejos-Médanos Basin: U.S.-Mexico transboundary water resources and research needs Mesilla / Conejos-Médanos Basin: U.S.-Mexico transboundary water resources and research needs
Synthesizing binational data to characterize shared water resources is critical to informing binational management. This work uses binational hydrogeology and water resource data in the Mesilla/Conejos-Médanos Basin (Basin) to describe the hydrologic conceptual model and identify potential research that could help inform sustainable management. The Basin aquifer is primarily composed of...
Authors
Andrew J. Robertson, Anne-Marie Matherne, Jeff D. Pepin, Andre B. Ritchie, Donald S. Sweetkind, Andrew Teeple, Alfredo Granados Olivas, Ana Cristina Garcia Vasquez, Kenneth C. Carroll, Erek H. Fuchs, Amy E. Galanter
Tectonostratigraphy and major structures of the Georgian Greater Caucasus: Implications for structural architecture, along-strike continuity, and orogen evolution Tectonostratigraphy and major structures of the Georgian Greater Caucasus: Implications for structural architecture, along-strike continuity, and orogen evolution
Although the Greater Caucasus Mountains have played a central role in absorbing late Cenozoic convergence between the Arabian and Eurasian plates, the orogenic architecture and the ways in which it accommodates modern shortening remain debated. Here, we addressed this problem using geologic mapping along two transects across the southern half of the western Greater Caucasus to reveal a...
Authors
Charles Cashman Trexler, Eric Cowgill, Nathan A Niemi, Dylan A Vasey, Tea Godoladze
Coastal paleogeography of the Pacific Northwest, USA, for the last 12,000 years accounting for three-dimensional earth structure Coastal paleogeography of the Pacific Northwest, USA, for the last 12,000 years accounting for three-dimensional earth structure
Predictive modeling of submerged archaeological sites requires accurate sea-level predictions in order to reconstruct coastal paleogeography and associated geographic features that may have influenced the locations of occupation sites such as rivers and embayments. Earlier reconstructions of the paleogeography of parts of the western U.S. coast used an assumption of eustatic sea level...
Authors
Jorie Clark, Jay R. Alder, Marisa Borreggine, Jerry X Mitrovica, Konstantin Latychev
Structural and functional landscape connectivity for lesser prairie-chickens in the Sand Shinnery Oak Prairie Ecoregion Structural and functional landscape connectivity for lesser prairie-chickens in the Sand Shinnery Oak Prairie Ecoregion
The lesser prairie-chicken (Tympanuchus pallidicinctus) is a species of conservation concern on the Southern High Plains of Texas and New Mexico, USA. Because fragmentation and isolation have increased since pre-settlement, dispersal through this heterogeneous landscape may be constrained, with serious implications for conservation and management of this species. Our objectives were to...
Authors
L.J. Schilder, L.J. Heintzman, N.E. Mcintyre, S. Harryman, C.A. Hagen, R. E. Martin, Clint W. Boal, Blake A. Grisham
Contributing areas to domestic wells in dipping sedimentary rocks under extreme recharge events Contributing areas to domestic wells in dipping sedimentary rocks under extreme recharge events
We use particle tracking to determine contributing areas (CAs) to wells for transient flow models that simulate cyclic domestic pumping and extreme recharge events in a small synthetic watershed underlain by dipping sedimentary rocks. The CAs consist of strike-oriented bands at locations where the water table intersects high-hydraulic conductivity beds, and from which groundwater flows...
Authors
Claire R. Tiedeman, Allen M. Shapiro
Disease and secondary sexual traits: Effects of pneumonia on horn size of bighorn sheep Disease and secondary sexual traits: Effects of pneumonia on horn size of bighorn sheep
Secondary sexual traits (e.g., horns and antlers) have ecological and evolutionary importance and are of management interest for game species. Yet, how these traits respond to emerging threats like infectious disease remains underexplored. Infectious pneumonia threatens bighorn sheep (Ovis canadensis) populations across North America and we hypothesized it may also reduce horn growth in...
Authors
Alynn Martin, John T. Hogg, Kezia R. Manlove, Tayler N LaSharr, Justin M. Shannon, Douglas E. McWhirter, Hollie Miyasaki, Kevin L. Monteith, Paul C. Cross
Regression of the Tethys Sea (central Asia) during middle to late Eocene: Evidence from calcareous nannofossils of western Tarim Basin, NW China Regression of the Tethys Sea (central Asia) during middle to late Eocene: Evidence from calcareous nannofossils of western Tarim Basin, NW China
Calcareous nannofossil assemblages from middle to upper Eocene sediments of the western Tarim Basin indicate two important episodes of marine incursion into the basin. The first episode represents a period of shallowing upward in the Wulagen Formation, which is dated as Zone CNE13 (Lutetian) by the co-occurrence of Discoaster bifax, Chiasmolithus solitus, and common Reticulofenestra...
Authors
Xuejiao Wang, Dangpeng Xi, David K. Watkins, Jean Self-Trail, Zihua Tang, Wenxin Cao, Tiantian Jiang, Muhammad Kamran, Xiaoqiao Wan
Multi-species amphibian monitoring across a protected landscape: Critical reflections on 15 years of wetland monitoring in Grand Teton and Yellowstone national parks Multi-species amphibian monitoring across a protected landscape: Critical reflections on 15 years of wetland monitoring in Grand Teton and Yellowstone national parks
Widespread amphibian declines were well documented at the end of the 20th century, raising concerns about the need to identify individual and interactive contributors to this global trend. At the same time, there was growing interest in the use of amphibians as ecological indicators. In the United States, wetland and amphibian monitoring programs were launched in some national parks as a...
Authors
Andrew M. Ray, Blake R. Hossack, William R. Gould, Debra A. Patla, Stephen Frank Spear, Robert W. Klaver, Paul E Bartelt, David P. Thoma, Kristin L Legg, Rob Daley, Charles R Peterson, P S Corn
Weakly supervised spatial deep learning for Earth image segmentation based on imperfect polyline labels Weakly supervised spatial deep learning for Earth image segmentation based on imperfect polyline labels
In recent years, deep learning has achieved tremendous success in image segmentation for computer vision applications. The performance of these models heavily relies on the availability of large-scale high-quality training labels (e.g., PASCAL VOC 2012). Unfortunately, such large-scale high-quality training data are often unavailable in many real-world spatial or spatiotemporal problems...
Authors
Zhe Jiang, Wenchong He, M. S. Kirby, Arpan Man Sainju, Shaowen Wang, Larry Stanislawski, Ethan J. Shavers, E. Lynn Usery