Potential role of acetyl-CoA synthetase (acs) and malate dehydrogenase (mae) in the evolution of the acetate switch in Bacteria and Archaea
Elliott P. Barnhart, Marcella A. McClure, Kiki Johnson, Sean Cleveland, Kristopher A. Hunt, Matthew W. Fields
2015, Scientific Reports (5) 1-10
Although many Archaea have AMP-Acs (acetyl-coenzyme A synthetase) and ADP-Acs, the extant methanogenic genus Methanosarcina is the only identified Archaeal genus that can utilize acetate via acetate kinase (Ack) and phosphotransacetylase (Pta). Despite the importance of ack as the potential urkinase in the ASKHA phosphotransferase superfamily, an origin hypothesis does...
Spatial and temporal variation in recruitment and growth of Channel Catfish Alabama bass and Tallapoosa Bass in the Tallapoosa River and associated tributaries
Elise R. Irwin, Taconya Goar
2015, Cooperator Science Series FWS/CSS -116
Effects of hydrology on growth and hatching success of age-0 black basses and Channel Catfish were examined in regulated and unregulated reaches of the Tallapoosa River, Alabama. Species of the family Centrarchidae, Ictalurus punctatus Channel Catfish and Pylodictis olivaris Flathead Catfish were also collected from multiple tributaries in the basin....
Arsenic and antimony geochemistry of mine wastes, associated waters and sediments at the Giant Mine, Yellowknife, Northwest Territories, Canada
Skya E. Fawcett, Heather E. Jamieson, D. Kirk Nordstrom, R. Blaine McCleskey
2015, Applied Geochemistry (62) 3-17
Elevated levels of arsenic (As) and antimony (Sb) in water and sediments are legacy residues found downstream from gold-mining activities at the Giant Mine in Yellowknife, Northwest Territories (NWT), Canada. To track the transport and fate of As and Sb, samples of mine-waste from the mill, and surface water, sediment,...
Viewing the status of Virginia’s environment through the lens of freshwater fishes
Paul L. Angermeier, M. J. Pinder
2015, Virginia Journal of Science (66) 147-169
No abstract available....
Synoptic evaluation of scale-dependent metrics for hydrographic line feature geometry
Larry V. Stanislawski, Barbara P. Buttenfield, Paulo Raposo, Madeline Cameron, Jeff T. Falgout
2015, Conference Paper, 18th ICA Workshop on Generalisation and Multiple Representation
Methods of acquisition and feature simplification for vector feature data impact cartographic representations and scientific investigations of these data, and are therefore important considerations for geographic information science (Haunert and Sester 2008). After initial collection, linear features may be simplified to reduce excessive detail or to furnish a reduced-scale version...
Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Zane Hills, Hughes and Shungnak quadrangles, Alaska
Melanie B. Werdon, Matthew Granitto, Jaime S. Azain
2015, Report
The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and...
Golden Eagle predation of an adult turkey vulture
Clint W. Boal
2015, Bulletin of the Texas Ornithological Society (48) 53-55
The Golden Eagle (Aquila chrysaetos) is a large, apex predator that occurs at low densities, has a long life span, experiences delayed maturity, has low reproductive rates, and has no natural predators (Watson 1997, Kochert et al. 2002). Golden Eagles are sensitive to anthropogenic driven landscape changes in land cover...
Land use structures fish assemblages in reservoirs of the Tennessee River
Leandro E. Miranda, J. M. Bies, D. A. Hann
2015, Marine and Freshwater Research (66) 526-534
Inputs of nutrients, sediments and detritus from catchments can promote selected components of reservoir fish assemblages, while hindering others. However, investigations linking these catchment subsidies to fish assemblages have generally focussed on one or a handful of species. Considering this paucity of community-level awareness, we sought to explore the association...
Sea lamprey mark type, wounding rate, and parasite-host preference and abundance relationships for lake trout and other species in Lake Ontario
Brian F. Lantry, Jean Adams, Gavin Christie, Teodore Schaner, James Bowlby, Michael Keir, Jana Lantry, Paul Sullivan, Daniel Bishop, Ted Treska, Bruce Morrison
2015, Report
We examined how the frequency of attacks by Sea Lamprey on fishes in Lake Ontario varied in response to Sea Lamprey abundance and preferred host abundance (Lake Trout >432mm). For this analysis we assembled seven data sets. Two fishery independent surveys for Lake Trout: US Geological Survey (USGS)/New York State...
Discrete-storm water-table fluctuation method to estimate episodic recharge.
John R. Nimmo, Charles Horowittz, Lara Mitchell
2015, Groundwater (53) 282-292
We have developed a method to identify and quantify recharge episodes, along with their associated infiltration-related inputs, by a consistent, systematic procedure. Our algorithm partitions a time series of water levels into discrete recharge episodes and intervals of no episodic recharge. It correlates each recharge episode with a specific interval...
Soil ecology of a rock outcrop ecosystem: Abiotic stresses, soil respiration, and microbial community profiles in limestone cedar glades
Jennifer M. Cartwright, E. Kudjo Advised by Dzantor
2015, Thesis
Limestone cedar glades are a type of rock outcrop ecosystem characterized by shallow soil and extreme hydrologic conditions—seasonally ranging from xeric to saturated—that support a number of plant species of conservation concern. Although a rich botanical literature exists on cedar glades, soil biochemical processes and the ecology of soil microbial...
From icefield to ocean - Explore the many ways that glaciers influence Alaska's Coastal Ecosystems.
Shad O’Neel, Eran Hood, Kristin Timm
2015, Report
No abstract available....
Treatment of trace organic compounds in common onsite wastewater systems
Robert Siegrist, Kathleen E. Conn
2015, Conference Paper, Innovation in soil-based onsite wastewater treatment
Onsite wastewater systems (OWS) have historically been relied on to treat conventional pollutants and pathogens in a fashion similar to that expected from centralized wastewater systems. However, based on the occurrence of, and potential effects from, contaminants of emerging concern in wastewaters, OWS as well as centralized systems need...
Automated lidar-derived canopy height estimates for the Upper Mississippi River System
Enrika Hlavacek
2015, Thesis
Land cover/land use (LCU) classifications serve as important decision support products for researchers and land managers. The LCU classifications produced by the U.S. Geological Survey’s Upper Midwest Environmental Sciences Center (UMESC) include canopy height estimates that are assigned through manual aerial photography interpretation techniques. In an effort to improve upon...
Uranium Sequestration During Biostimulated Reduction and In Response to the Return of Oxic Conditions In Shallow Aquifers
Christopher C. Fuller, Kelly J. Johnson, Katherine Akstin, David M. Singer, Steven B. Yabusaki, Yi Fang, M. Fuhrmann
2015, Report
A proposed approach for groundwater remediation of uranium contamination is to generate reducing conditions by stimulating the growth of microbial populations through injection of electron donor compounds into the subsurface. Sufficiently reducing conditions will result in reduction of soluble hexavalent uranium, U(VI), and precipitation of the less soluble +4 oxidation...
Geology and neotectonism in the epicentral area of the 2011 M5.8 Mineral, Virginia, earthquake
William C. Burton, David B. Spears, Richard W. Harrison, Nicholas H. Evans, J. Stephen Schindler, Ronald C. Counts
2015, Field Guides (35) 103-127
This fi eld guide covers a two-day west-to-east transect across the epicentral region of the 2011 M5.8 Mineral, Virginia, earthquake, the largest ever recorded in the Central Virginia seismic zone. The fi eld trip highlights results of recent bedrock and surficial geologic mapping in two adjoining 7.5-min quadrangles, the Ferncliff...
Validation of the SCEC broadband platform V14.3 simulation methods using pseudo spectral acceleration data
Douglas S. Dreger, Gregory C. Beroza, Steven M. Day, Christine A. Goulet, Thomas H Jordan, Paul A. Spudich, Jonathan P. Stewart
2015, Seismological Research Letters (86) 39-47
This paper summarizes the evaluation of ground motion simulation methods implemented on the SCEC Broadband Platform (BBP), version 14.3 (as of March 2014). A seven-member panel, the authorship of this article, was formed to evaluate those methods for the prediction of pseudo-‐spectral accelerations (PSAs) of ground motion. The panel’s mandate...
An updated conceptual model of Delta Smelt biology: Our evolving understanding of an estuarine fish
Randy Baxter, Larry R. Brown, Gonzalo Castillo, Louise Conrad, Steven D. Culberson, Matthew P. Dekar, Melissa Dekar, Frederick Feyrer, Thaddeus Hunt, Kristopher Jones, Joseph Kirsch, Anke Mueller-Solger, Matthew Nobriga, Steven B. Slater, Ted Sommer, Kelly Souza, Gregg Erickson, Stephanie Fong, Karen Gehrts, Lenny Grimaldo, Bruce Herbold
2015, Technical Report 90
The main purpose of this report is to provide an up-to-date assessment and conceptual model of factors affecting Delta Smelt (Hypomesus transpacificus) throughout its primarily annual life cycle and to demonstrate how this conceptual model can be used for scientific and management purposes. The Delta Smelt is a small estuarine...
Complex interactions between global change drivers influence mountain forest and slpine GHG sequestration and stream chemistry
Jill Baron, Melannie D. Hartman
2015, Conference Paper, Mountain Views
Many mountain ecosystems are experiencing coincident increases in temperature, levels of atmospheric carbon dioxide (CO2) and atmospheric nitrogen (N) deposition. All are important controls on rates of plant growth, soil microbial activity, nutrient cycling, and stream N export. It is difficult for experimental studies to explore ecosystem responses to more than one or two treatments at...
Examining the utility of satellite-based wind sheltering estimates for lake hydrodynamic modeling
Jamon Van Den Hoek, Jordan S. Read, Luke A. Winslow, Paul Montesano, Corey D. Markfort
2015, Remote Sensing of Environment (156) 551-560
Satellite-based measurements of vegetation canopy structure have been in common use for the last decade but have never been used to estimate canopy's impact on wind sheltering of individual lakes. Wind sheltering is caused by slower winds in the wake of topography and shoreline obstacles (e.g. forest canopy) and influences...
Estimating relative sea-level rise and submergence potential at a coastal wetland
Donald R. Cahoon
2015, Estuaries and Coasts (38) 1077-1084
A tide gauge records a combined signal of the vertical change (positive or negative) in the level of both the sea and the land to which the gauge is affixed; or relative sea-level change, which is typically referred to as relative sea-level rise (RSLR). Complicating this situation, coastal wetlands exhibit...
Atmospheric particulate matter in proximity to mountaintop coal mines: Sources and potential environmental and human health impacts
Laura Kurth, Allan Kolker, Mark A. Engle, Nicholas J. Geboy, Michael Hendryx, William H. Orem, Michael McCawley, Lynn M. Crosby, Calin A. Tatu, Matthew S. Varonka, Christina A. DeVera
2015, Environmental Geochemistry and Health (37) 529-544
Mountaintop removal mining (MTM) is a widely used approach to surface coal mining in the US Appalachian region whereby large volumes of coal overburden are excavated using explosives, removed, and transferred to nearby drainages below MTM operations. To investigate the air quality impact of MTM, the geochemical characteristics of atmospheric...
Tracing historical trends of Hg in the Mississippi River using Hg concentrations and Hg isotopic compositions in a lake sediment core, Lake Whittington, Mississippi, USA
John E. Gray, Peter C. Van Metre, Michael J. Pribil, Arthur J. Horowitz
2015, Chemical Geology (395) 80-87
Concentrations and isotopic compositions of mercury (Hg) in a sediment core collected from Lake Whittington, an oxbow lake on the Lower Mississippi River, were used to evaluate historical sources of Hg in the Mississippi River basin. Sediment Hg concentrations in the Lake Whittington core have a large 10-15 y peak...
Comparison of fluvial suspended-sediment concentrations and particle-size distributions measured with in-stream laser diffraction and in physical samples
Jonathan A. Czuba, Timothy D. Straub, Christopher A. Curran, Mark N. Landers, Marian M. Domanski
2015, Water Resources Research (51) 320-340
Laser-diffraction technology, recently adapted for in-stream measurement of fluvial suspended-sediment concentrations (SSCs) and particle-size distributions (PSDs), was tested with a streamlined (SL), isokinetic version of the Laser In-Situ Scattering and Transmissometry (LISST) for measuring volumetric SSCs and PSDs ranging from 1.8-415 µm in 32 log-spaced size classes. Measured SSCs and...
Sensitivity of tsunami evacuation modeling to direction and land cover assumptions
Mathew C. Schmidtlein, Nathan J. Wood
2015, Applied Geography (56) 154-163
Although anisotropic least-cost-distance (LCD) modeling is becoming a common tool for estimating pedestrian-evacuation travel times out of tsunami hazard zones, there has been insufficient attention paid to understanding model sensitivity behind the estimates. To support tsunami risk-reduction planning, we explore two aspects of LCD modeling as it applies to pedestrian...
