Estimated variability of National Atmospheric Deposition Program/Mercury Deposition Network measurements using collocated samplers
G.A. Wetherbee, D.A. Gay, R.C. Brunette, C.W. Sweet
2007, Environmental Monitoring and Assessment (131) 49-69
The National Atmospheric Deposition Program/Mercury Deposition Network (MDN) provides long-term, quality-assured records of mercury in wet deposition in the USA and Canada. Interpretation of spatial and temporal trends in the MDN data requires quantification of the variability of the MDN measurements. Variability is quantified for MDN data from collocated samplers...
Wildlife species associated with non-coniferous vegetation in Pacific Northwest conifer forests: A review
J.C. Hagar
2007, Forest Ecology and Management (246) 108-122
Non-coniferous vegetation, including herbs, shrubs, and broad-leaved trees, makes a vital contribution to ecosystem function and diversity in Pacific Northwest conifer forests. However, forest management has largely been indifferent or detrimental to shrubs and trees that have low commercial value, in spite of a paradigm shift towards more holistic management...
Lethal and sublethal effects of ammonia to juvenile Lampsilis mussels (Unionidae) in sediment and water-only exposures
T.J. Newton, M.R. Bartsch
2007, Environmental Toxicology and Chemistry (26) 2057-2065
We compared the sensitivity of two juvenile unionid mussels (Lampsilis cardium and Lampsilis higginsii) to ammonia in 96-h water-only and sediment tests by use of mortality and growth measurements. Twenty mussels were placed in chambers buried 2.5 cm into reference sediments to approximate pore-water exposure (sediment tests) or elevated above...
Identification of plasma glucocorticoids in pallid sturgeon in response to stress
M.A.H. Webb, J.A. Allert, K.M. Kappenman, J. Marcos, G.W. Feist, C.B. Schreck, C.H. Shackleton
2007, General and Comparative Endocrinology (154) 98-104
Compared to teleosts, little is known about the stress response in chondrosteans, and the glucocorticoid(s) most responsive to stress have never been definitively determined in sturgeon. In terms of cortisol production, pallid sturgeon (Scaphirhynchus albus) have a low physiological response to stress compared to other sturgeons (Acipenser sp.). Because of...
Effect of relative volume on radio transmitter expulsion in subadult common carp
C.R. Penne, N.L. Ahrens, R.C. Summerfelt, C.L. Pierce
2007, North American Journal of Fisheries Management (27) 986-991
Expulsion of surgically implanted radio transmitters is a problem in some fish telemetry studies. We conducted a 109-d experiment to test the hypothesis that variation in relative volume of transmitters surgically implanted in subadult common carp Cyprinus carpio would affect transmitter expulsion. We also necropsied fish at the end of...
Cadmium ecophysiology in seven stonefly (Plecoptera) species: Delineating sources and estimating susceptibility
C.A. Martin, S. N. Luoma, D.J. Cain, D.B. Buchwalter
2007, Environmental Science & Technology (41) 7171-7177
A major challenge in ecotoxicology lies in generating data under experimental conditions that are relevant to understanding contaminant effects in nature. Biodynamic modeling combines species-specific physiological traits to make predictions of metal bioaccumulation that fare well when tested in the field....
Selection of den sites by black bears in the southern Appalachians
M. J. Reynolds-Hogland, M.S. Mitchell, R. A. Powell, D.C. Brown
2007, Journal of Mammalogy (88) 1062-1073
We evaluated selection of den sites by American black bears (Ursus americanus) in the Pisgah Bear Sanctuary, western North Carolina, by comparing characteristics of dens at 53 den sites with availability of habitat characteristics in annual home ranges of bears and in the study area. We also tested whether den-site...
Pesticide and transformation product detections and age-dating relations from till and sand deposits
K.L. Warner, W.S. Morrow
2007, Journal of the American Water Resources Association (43) 911-922
Pesticide and transformation product concentrations and frequencies in ground water from areas of similar crop and pesticide applications may vary substantially with differing lithologies. Pesticide analysis data for atrazine, metolachlor, alachlor, acetochlor, and cyanazine and their pesticide transformation products were collected at 69 monitoring wells in Illinois and northern Indiana...
Tree and stand transpiration in a Midwestern bur oak savanna after elm encroachment and restoration thinning
H. Asbjornsen, M.D. Tomer, M. Gomez-Cardenas, L.A. Brudvig, C.M. Greenan, K. Schilling
2007, Forest Ecology and Management (247) 209-219
Oak savannas, once common in the Midwest, are now isolated remnants within agricultural landscapes. Savanna remnants are frequently encroached by invasive trees to become woodlands. Thinning and prescribed burning can restore savanna structure, but the ecohydrological effects of managing these remnants are poorly understood. In this study, we measured sap...
Lithology-derived structure classification from the joint interpretation of magnetotelluric and seismic models
P. A. Bedrosian, N. Maercklin, U. Weckmann, Y. Bartov, T. Ryberg, O. Ritter
2007, Geophysical Journal International (170) 737-748
Magnetotelluric and seismic methods provide complementary information about the resistivity and velocity structure of the subsurface on similar scales and resolutions. No global relation, however, exists between these parameters, and correlations are often valid for only a limited target area. Independently derived inverse models from these methods can be combined...
Comparison of earthquake source spectra and attenuation in eastern North America and southeastern Australia
T.I. Allen, G. M. Atkinson
2007, Bulletin of the Seismological Society of America (97) 1350-1354
The paucity of ground-motion data in stable continental regions (SCRs) remains a key limitation when developing relations that seek to predict effects of strong ground shaking from large damaging earthquakes. It is desirable to combine data from more than one SCR to increase database size, but this raises questions as...
Mineralogic constraints on sulfur-rich soils from Pancam spectra at Gusev crater, Mars
J. R. Johnson, J.F. Bell, E. Cloutis, M. Staid, W. H. Farrand, T. McCoy, M. Rice, A. Wang, A. Yen
2007, Geophysical Research Letters (34)
The Mars Exploration Rover (MER) Spirit excavated sulfur-rich soils exhibiting high albedo and relatively white to yellow colors at three main locations on and south of Husband Hill in Gusev crater, Mars. The multispectral visible/near-infrared properties of these disturbed soils revealed by the Pancam stereo color camera vary appreciably over...
Three-dimensional flow in the Florida platform: Theoretical analysis of Kohout convection at its type locality
J.D. Hughes, H. Leonard Vacher, Ward E. Sanford
2007, Geology (35) 663-666
Kohout convection is the name given to the circulation of saline groundwater deep within carbonate platforms, first proposed by F.A. Kohout in the 1960s for south Florida. It is now seen as an Mg pump for dolomitization by seawater. As proposed by Kohout, cold seawater is drawn into the Florida...
Measurements of storm and nonstorm circulation in the northern Adriatic: October 2002 Through April 2003
J.W. Book, R. P. Signell, H. Perkins
2007, Journal of Geophysical Research C: Oceans (112)
Fifteen bottom-mounted Acoustic Doppler Current Profilers were deployed from October 2002 through April 2003 in the northern Adriatic Sea. Average transport from the portion of the Western Adriatic Current (WAC) along the Italian slope was 0.1470 ?? 0.0043 Sv, punctuated by bursts of more than twice that amount during storm...
Migratory movements of pacu, Piaractus mesopotamicus, in the highly impounded Paraná River
M.C. Makrakis, L.E. Miranda, S. Makrakis, A.M.M. Xavier, H.M. Fontes, W.G. Morlis
2007, Journal of Applied Ichthyology (23) 700-704
A mark-recapture study was conducted in 1997–2005 to investigate movements of stocked pacu, Piaractus mesopotamicus, in the Paraná River Basin of Brazil, Paraguay, and Argentina. Fish raised in cages within the Itaipu Reservoir and in ponds were tagged externally (n = 2976) and released in the Itaipu Reservoir (53.2%) and bays of its...
Modeling aboveground biomass of Tamarix ramosissima in the Arkansas River Basin of Southeastern Colorado, USA
P. Evangelista, S. Kumar, T.J. Stohlgren, A.W. Crall, G.J. Newman
2007, Western North American Naturalist (67) 503-509
Predictive models of aboveground biomass of nonnative Tamarix ramosissima of various sizes were developed using destructive sampling techniques on 50 individuals and four 100-m2 plots. Each sample was measured for average height (m) of stems and canopy area (m2) prior to cutting, drying, and weighing. Five competing regression models (P...
Correcting acoustic Doppler current profiler discharge measurements biased by sediment transport
D. S. Mueller, C. R. Wagner
2007, Journal of Hydraulic Engineering (133) 1329-1336
A negative bias in discharge measurements made with an acoustic Doppler current profiler (ADCP) is attributed to the movement of sediment on or near the streambed, and is an issue widely acknowledged by the scientific community. The integration of a differentially corrected global positioning system (DGPS) to track the movement...
Late Quaternary distal tephra-fall deposits in lacustrine sediments, Kenai Peninsula, Alaska
C.S. de Fontaine, D. S. Kaufman, Anderson R. Scott, A. Werner, Christopher F. Waythomas, T.A. Brown
2007, Quaternary Research (68) 64-78
Tephra-fall deposits from Cook Inlet volcanoes were detected in sediment cores from Tustumena and Paradox Lakes, Kenai Peninsula, Alaska, using magnetic susceptibility and petrography. The ages of tephra layers were estimated using 21 14C ages on macrofossils. Tephras layers are typically fine, gray ash, 1–5 mm thick, and composed of varying...
Effects of anthropogenic developments on common Raven nesting biology in the west Mojave Desert
W. B. Kristan III, W.I. Boarman
2007, Ecological Applications (17) 1703-1713
Subsidized predators may affect prey abundance, distribution, and demography. Common Ravens (Corvus corax) are anthropogenically subsidized throughout their range and, in the Mojave Desert, have increased in number dramatically over the last 3-4 decades. Human-provided food resources are thought to be important drivers of raven population growth, but human developments...
Evaluation of mean velocity and turbulence measurements with ADCPs
E.A. Nystrom, C.R. Rehmann, K. A. Oberg
2007, Journal of Hydraulic Engineering (133) 1310-1318
To test the ability of acoustic Doppler current profilers (ADCPs) to measure turbulence, profiles measured with two pulse-to-pulse coherent ADCPs in a laboratory flume were compared to profiles measured with an acoustic Doppler velocimeter, and time series measured in the acoustic beam of the ADCPs were examined. A four-beam ADCP...
Organic petrology of Paleocene Marcelina Formation coals, Paso Diablo mine, western Venezuela: Tectonic controls on coal type
P.C. Hackley, M. Martinez
2007, International Journal of Coal Geology (71) 505-526
About 7??Mt of high volatile bituminous coal are produced annually from the four coal zones of the Upper Paleocene Marcelina Formation at the Paso Diablo open-pit mine of western Venezuela. As part of an ongoing coal quality study, we have characterized twenty-two coal channel samples from the mine using organic...
Reducing energy-related CO2 emissions using accelerated weathering of limestone
Greg H. Rau, Kevin G. Knauss, William H. Langer, Ken Caldeira
2007, Energy (32) 1471-1477
The use and impacts of accelerated weathering of limestone (AWL; reaction: CO2+H2O+CaCO3→Ca2++2(HCO3-) is explored as a CO2 capture and sequestration method. It is shown that significant limestone resources are relatively close to a majority of CO2-emitting power plants along the coastal US, a favored siting location for AWL. Waste fines,...
Competitive release and facilitation of drug-resistant parasites after therapeutic chemotherapy in a rodent malaria model
A. R. Wargo, S. Huijben, J. C. De Roode, J. Shepherd, A.F. Read
2007, Proceedings of the National Academy of Sciences of the United States of America (104) 19914-19919
Malaria infections frequently consist of mixtures of drug-resistant and drug-sensitive parasites. If crowding occurs, where clonal population densities are suppressed by the presence of coinfecting clones, removal of susceptible clones by drug treatment could allow resistant clones to expand into the newly vacated niche space within a host. Theoretical models...
Three-dimensional P wave velocity model for the San Francisco Bay region, California
C.H. Thurber, T.M. Brocher, H. Zhang, V.E. Langenheim
2007, Journal of Geophysical Research B: Solid Earth (112)
[1] A new three-dimensional P wave velocity model for the greater San Francisco Bay region has been derived using the double-difference seismic tomography method, using data from about 5,500 chemical explosions or air gun blasts and approximately 6,000 earthquakes. The model region covers 140 km NE-SW by 240...
A global search inversion for earthquake kinematic rupture history: Application to the 2000 western Tottori, Japan earthquake
A. Piatanesi, A. Cirella, P. Spudich, M. Cocco
2007, Journal of Geophysical Research B: Solid Earth (112)
[1] We present a two-stage nonlinear technique to invert strong motions records and geodetic data to retrieve the rupture history of an earthquake on a finite fault. To account for the actual rupture complexity, the fault parameters are spatially variable peak slip velocity, slip direction,...
