Microbial arsenic metabolism: New twists on an old poison
J.F. Stolz, P. Basu, Ronald S. Oremland
2010, Microbe (5) 53-59
Phylogenetically diverse microorganisms metabolize arsenic despite its toxicity and are part of its robust iogeochemical cycle. Respiratory arsenate reductase is a reversible enzyme, functioning in some microbes as an arsenate reductase but in others as an arsenite oxidase. As(III) can serve as an electron donor for anoxygenic photolithoautotrophy and chemolithoautotrophy....
Emplacement of the youngest flood lava on Mars: A short, turbulent story
Windy L. Jaeger, Laszlo P. Keszthelyi, James A. Skinner, Moses P. Milazzo, Alfred S. McEwen, Timothy N. Titus, Mark R. Rosiek, Donna M. Galuszka, Elpitha Howington-Kraus, Randolph L. Kirk, the HiRISE TEam
2010, Icarus (205) 230-243
Recently acquired data from the High Resolution Imaging Science Experiment (HiRISE), Context (CTX) imager, and Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) onboard the Mars Reconnaissance Orbiter (MRO) spacecraft were used to investigate the emplacement of the youngest flood-lava flow on Mars. Careful mapping finds that...
Anthropogenic influence on recent bathymetric change in west-central San Francisco Bay
Patrick L. Barnard, Rikk G. Kvitek
2010, San Francisco Estuary and Watershed Science (8)
Two multibeam sonar surveys of west-central San Francisco Bay, California, were conducted in 1997 and 2008. Bathymetric change analysis between the two surveys indicates a loss of 14.1 million cubic meters (-3.1 cm/yr) of sediment during this time period, representing an approximately three-fold acceleration of the rate that was observed...
HiRISE observations of gas sublimation-driven activity in Mars' southern polar regions: III. Models of processes involving translucent ice
Ganna Portyankina, Wojciech J. Markiewicz, Nicolas Thomas, Candice J. Hansen, Moses P. Milazzo
2010, Icarus (205) 311-320
Enigmatic surface features, known as 'spiders', found at high southern martian latitudes, are probably caused by sublimation-driven erosion under the seasonal carbon dioxide ice cap. The Mars Reconnaissance Orbiter (MRO) High Resolution Imaging Science Experiment (HiRISE) has imaged this terrain in unprecedented details throughout southern spring. It has been postulated...
Food habits of stunted and non-stunted white perch (Morone americana)
N.J.C. Gosch, J.R. Stittie, K.L. Pope
2010, Journal of Freshwater Ecology (25) 31-39
We studied food habits of white perch (Morone americana) from two populations with different stable states (stunted [Branched Oak Lake, Nebraska] and non-stunted [Pawnee Lake, Nebraska]) to determine if change in food habits of white perch is likely to occur in situations where a stunted white perch population is altered...
Decadal-timescale estuarine geomorphic change under future scenarios of climate and sediment supply
N. K. Ganju, D. H. Schoellhamer
2010, Estuaries and Coasts (33) 15-29
Future estuarine geomorphic change, in response to climate change, sea-level rise, and watershed sediment supply, may govern ecological function, navigation, and water quality. We estimated geomorphic changes in Suisun Bay, CA, under four scenarios using a tidal-timescale hydrodynamic/sediment transport model. Computational expense and data needs were reduced using the morphological...
The green alga, Cladophora, promotes Escherichia coli growth and contamination of recreational waters in Lake Michigan
A.V. Heuvel, C. McDermott, R. Pillsbury, T. Sandrin, J. Kinzelman, J. Ferguson, M. Sadowsky, M. Byappanahalli, R. Whitman, G.T. Kleinheinz
2010, Journal of Environmental Quality (39) 333-344
A linkage between Cladophora mats and exceedances of recreational water quality criteria has been suggested, but not directly studied. Th is study investigates the spatial and temporal association between Escherichia coli concentrations within and near Cladophora mats at two northwestern Lake Michigan beaches in Door County, Wisconsin. Escherichia coli concentrations...
Environmental conditions and biotic interactions influence ecosystem structure and function in a drying stream
J.P. Ludlam, D.D. Magoulick
2010, Hydrobiologia (644) 127-137
Benthic consumers influence stream ecosystem structure and function, but these interactions depend on environmental context. We experimentally quantified the effects of central stoneroller minnows (Campostoma anomalum (Rafinesque) and Meek's crayfish (Orconectes meeki meeki (Faxon)) on benthic communities using electric exclusion quadrats in Little Mulberry Creek before (June) and during (August)...
A Bayesian approach to identifying structural nonlinearity using free-decay response: Application to damage detection in composites
J.M. Nichols, W.A. Link, K.D. Murphy, C.C. Olson
2010, Journal of Sound and Vibration (329) 2995-3007
This work discusses a Bayesian approach to approximating the distribution of parameters governing nonlinear structural systems. Specifically, we use a Markov Chain Monte Carlo method for sampling the posterior parameter distributions thus producing both point and interval estimates for parameters. The method is first used to identify both linear and...
Prescribed fires as ecological surrogates for wildfires: A stream and riparian perspective
R.S. Arkle, D. S. Pilliod
2010, Forest Ecology and Management (259) 893-903
Forest managers use prescribed fire to reduce wildfire risk and to provide resource benefits, yet little information is available on whether prescribed fires can function as ecological surrogates for wildfire in fire-prone landscapes. Information on impacts and benefits of this management tool on stream and riparian ecosystems is particularly lacking....
Modeling the relations between flow regime components, species traits, and spawning success of fishes in warmwater streams
S.W. Craven, J.T. Peterson, Mary C. Freeman, T.J. Kwak, E. Irwin
2010, Environmental Management (46) 181-194
Modifications to stream hydrologic regimes can have a profound influence on the dynamics of their fish populations. Using hierarchical linear models, we examined the relations between flow regime and young-of-year fish density using fish sampling and discharge data from three different warmwater streams in Illinois, Alabama, and Georgia. We used...
Silica-rich deposits and hydrated minerals at Gusev Crater, Mars: Vis-NIR spectral characterization and regional mapping
M.S. Rice, J.F. Bell III, E.A. Cloutis, A. Wang, S. W. Ruff, M.A. Craig, D.T. Bailey, J. R. Johnson, P.A. De Souza Jr., W. H. Farrand
2010, Icarus (205) 375-395
The Mars Exploration Rover (MER) Spirit has discovered surprisingly high concentrations of amorphous silica in soil and nodular outcrops in the Inner Basin of the Columbia Hills. In Pancam multispectral observations, we find that an absorption feature at the longest Pancam wavelength (1009 nm) appears to be characteristic of these...
Predicting the retreat and migration of tidal forests along the northern Gulf of Mexico under sea-level rise
T.W. Doyle, K. W. Krauss, W.H. Conner, A.S. From
2010, Forest Ecology and Management (259) 770-777
Tidal freshwater forests in coastal regions of the southeastern United States are undergoing dieback and retreat from increasing tidal inundation and saltwater intrusion attributed to climate variability and sea-level rise. In many areas, tidal saltwater forests (mangroves) contrastingly are expanding landward in subtropical coastal reaches succeeding freshwater marsh and forest...
MTBE, TBA, and TAME attenuation in diverse hyporheic zones
James Landmeyer, Paul M. Bradley, D.A. Trego, K.G. Hale, J.E. Haas II
2010, Ground Water (48) 30-41
Groundwater contamination by fuel-related compounds such as the fuel oxygenates methyl tert-butyl ether (MTBE), tert-butyl alcohol (TBA), and tert-amyl methyl ether (TAME) presents a significant issue to managers and consumers of groundwater and surface water that receives groundwater discharge. Four sites were investigated on Long Island, New York, characterized by...
Eolian transport of geogenic hexavalent chromium to ground water
W.W. Wood, D. Clark, J. L. Imes, T.B. Councell
2010, Ground Water (48) 19-29
A conceptual model of eolian transport is proposed to address the widely distributed, high concentrations of hexavalent chromium (Cr+6) observed in ground water in the Emirate of Abu Dhabi, United Arab Emirates. Concentrations (30 to more than 1000 μg/L Cr+6) extend over thousands of square kilometers of ground water systems....
Morphologic dating of fault scarps using airborne laser swath mapping (ALSM) data
G.E. Hilley, S. Delong, C. Prentice, K. Blisniuk, J.R. Arrowsmith Jr.
2010, Geophysical Research Letters (37)
Models of fault scarp morphology have been previously used to infer the relative age of different fault scarps in a fault zone using labor-intensive ground surveying. We present a method for automatically extracting scarp morphologic ages within high-resolution digital topography. Scarp degradation is modeled as a diffusive mass transport process...
Bringing wisents back to the Caucasus Mountains: 70 years of a grand mission
Taras Sipko, Sergei Trepet, Peter J. Gogan, Ivan Mizin
2010, European Bison Conservation Newletter (3) 33-44
We describe the history of mountain wisent restoration in the north-west Caucasus region. We review information on wisent during the 18th and 19th centuries, contemporary regional development and reasons for wisent extirpation. We emphasize the key role of the Kuban Hunting Reserve as a main factor in preserving wisent in...
Elwha River dam removal: A major opportunity for salmon and steelhead recolonization
George R. Pess, Samuel J. Brenkman, Gary A. Winans, Michael L. McHenry, Jeffrey J. Duda, Timothy J. Beechie
2010, Osprey
In this in-depth paper, authors George R. Pess, Gary A. Winans and Timothy J. Beechie of the NOAA Fisheries, Northwest Fisheries Science Center in Seattle, Samuel J. Brenkman of the National Park Service, Olympic National Park, Michael L. McHenry of the Lower Elwha Klallam Tribe and Jeffrey J. Duda of...
Sources of suspended-sediment flux in streams of the chesapeake bay watershed: A regional application of the sparrow model
J. W. Brakebill, S.W. Ator, G. E. Schwarz
2010, Journal of the American Water Resources Association (46) 757-776
We describe the sources and transport of fluvial suspended sediment in nontidal streams of the Chesapeake Bay watershed and vicinity. We applied SPAtially Referenced Regressions on Watershed attributes, which spatially correlates estimated mean annual flux of suspended sediment in nontidal streams with sources of suspended sediment and transport factors. According...
Polychlorinated biphenyls, dioxins, furans, and organochlorine pesticides in spotted sandpiper eggs from the upper Hudson River basin, New York
Thomas W. Custer, Christine M. Custer, Brian R. Gray
2010, Ecotoxicology (19) 391-404
In 2004, spotted sandpipers (Actitis macularia) were studied on the Hudson River near Fort Edward south to New Baltimore, NY and on two river drainages that flow into the Hudson River. Concentrations of 28 organochlorine pesticides, 160 polychlorinated biphenyl (PCB) congeners, and 17 dioxin and furan (PCDD-F) congeners...
Housing growth in and near United States protected areas limits their conservation value
V. C. Radeloff, S. I. Stewart, T. J. Hawbaker, U. Gimmi, A.M. Pidgeon, C.H. Flather, R. B. Hammer, D.P. Helmers
2010, Proceedings of the National Academy of Sciences of the United States of America (107) 940-945
Protected areas are crucial for biodiversity conservation because they provide safe havens for species threatened by land-use change and resulting habitat loss. However, protected areas are only effective when they stop habitat loss within their boundaries, and are connected via corridors to other wild areas. The effectiveness of protected areas...
On the specification of structural equation models for ecological systems
James B. Grace, T. Michael Anderson, Han Olff, S.M. Scheiner
2010, Ecological Monographs (80) 67-87
The use of structural equation modeling (SEM) is often motivated by its utility for investigating complex networks of relationships, but also because of its promise as a means of representing theoretical concepts using latent variables. In this paper, we discuss characteristics of ecological theory and some of the challenges for...
Wound repair in Montipora capitata
Thierry M. Work, Greta S. Aeby
2010, Journal of Invertebrate Pathology (105) 116-119
We documented the microscopic morphology of tissue healing in Montipora capitata. Fragments from two healthy coral colonies were traumatized by scraping tissue and skeleton and monitored in flow-through seawater tables every 2-4. days for 40. days for gross and cellular changes. Grossly, corals appeared healed and repigmented by Day 40....
A revised ground-motion and intensity interpolation scheme for shakemap
C.B. Worden, D.J. Wald, T.I. Allen, K. Lin, D. Garcia, G. Cua
2010, Bulletin of the Seismological Society of America (100) 3083-3096
We describe a weighted-average approach for incorporating various types of data (observed peak ground motions and intensities and estimates from groundmotion prediction equations) into the ShakeMap ground motion and intensity mapping framework. This approach represents a fundamental revision of our existing ShakeMap methodology. In addition, the increased availability of near-real-time...
The role of soil drainage class in carbon dioxide exchange and decomposition in boreal black spruce (Picea mariana) forest stands
K.P. Wickland, J. C. Neff, J.W. Harden
2010, Canadian Journal of Forest Research (40) 2123-2134
Black spruce (Picea mariana (Mill.) B.S.P.) forest stands range from well drained to poorly drained, typically contain large amounts of soil organic carbon (SOC), and are often underlain by permafrost. To better understand the role of soil drainage class in carbon dioxide (CO2) exchange and decomposition, we measured soil respiration...
